FR2788393A1 - Mobile telephone E-mail multiple terminal digital communication access technique having terminal selecting front end code and base post transmitting and searching possible codes/acquiring or terminal resending. - Google Patents

Abstract

The common channel direct access code division multiplexed access system has multiple terminals (100) transmitting digital words to a base post (200) using a communications channel. The base post receives digital word signals with front end codes, which are not address related, being selected by each of the multiple terminals. The base post searches all possible front end codes, to acquire the signal. If the base post acquires the front end code the terminal transmits the digital words, otherwise re transmitting the front end code.

Description

DEVICE AND METHOD FOR DIRECT ACCESS THROUGH

  OF A COMMON CHANNEL WITH A REVERSE LINK WHEN ACCESSING

MULTIPLE BY CODE DISTRIBUTION

  The present invention relates to a direct access device and method in which multiple terminals transmit data via a common channel according to a code division multiple access method, and more particularly, to a direct access device and method in which terminals select one of available preamble signatures and one of available access time slots and transmit a preamble, a base station attempts to acquire the preamble and broadcasts to all terminals the knowledge that the preambles are or are not acquired, and the terminals transmit data or retransmit a preamble depending on the result of the preamble acquisition. The device and method make it possible to improve the efficiency of a network 20 by reducing all transmission of unnecessary data and any interference signal and have an improved time delay characteristic by retransmitting preamble by preamble and climbing to a level of adequate power faster.25 At present, the demand for telecommunications in the mobile service is constantly increasing, the service can transmit voice information while on the move, but it cannot support data transmission. However, there is a growing demand for a service for transmitting simple data such as electronic mail (E-mail) to moving image data. In particular, there are studies from the International Mobile Telecommunication-2000 (IMT-2000) 35 for other telecommunications in the mobile service 2 capable of providing services anywhere in the world by means of a unified international standard. by supporting not only voice information but also a moving image. For example, in a wireless local area network (LAN), represented by the IEEE 802.11 standard, products capable of transmitting data at 2 Mbps (megabinary per second) are

usually used.

  In general, since a public switched telephone network (PSTN) or circuit switching method, used for a personal communication system or a digital cellular system, inefficiently uses a limited channel, they are not suitable for data transmission. Thus, in a local area network (LAN) or IMT-2000 system under study as a standard for the next generation of communication systems

  mobile telecommunications, a packet switching method is designed to overcome the disadvantages of the circuit switching method and to transmit data at variable speeds.

  Conversely, a spread spectrum method, a code division multiple access (CDMA) signaling method applied in a common digital cellular system, has the advantages of increased acceptance capacity, impossibility of pirate listening, stable communication even in multi-path environments occurring during a change of wireless channel. Now, support for both existing voice information and packet data is required in an IMT-2000 system which is in the process of standardization, however, the method using a dedicated channel as in a conventional voice service cannot use a source efficiently because of the non-periodic characteristic of packet data. A 3 namely, while data occurring in a way

  continuous, such as voice information, use a dedicated dedicated channel, discontinuous packet data, the speeds of which are variable, decrease the capacity of the system when dedicated channels are used.

  Thus, when a correct number of reverse link channels are used in common, a source is used efficiently and services with varying speeds as well as voice service can be accepted simultaneously as far as the

  system capacity. In addition, it is expected that the number of subscribers will increase and that the amount of data to be transmitted will increase, so efficient use of a source using a common reverse link channel will be necessary.

  An ALOHA method, among the channel access and data transmission methods using the common reverse link channel, is known to be the simplest method. The ALOHA process is a classic direct access process, it was developed as a protocol for a wireless network between the islands of the states of Hawaii at the University of Hawaii in 1970. However, in the ALOHA process, Since data is transmitted without a particular time schedule between a base station and a terminal, the efficiency of data transmission decreases. And, overloads can occur on many terminals, because data transmission collapses tend to increase. An ALOHA process subdivided in time by specific times between a base station and a terminal has been studied to solve the problems. The ALOHA process subdivided in time is a process by which data transmission is authorized35 only at a specific time even if data to be transmitted occurs at the level of a terminal, thus

  the efficiency of data transmission is increased, because the risk of data transmission interfering with data occurring at another terminal is decreased, and overall, the efficiency of a network is improved.

  FIG. 1 is a diagram representing a data transmission according to an ALOHA protocol

  using a prior code division multiple access method.

  According to FIG. 1, a terminal transmits data via a particular access attempt, the access attempt consists of multiple secondary access attempts, the secondary access attempt consists of multiple access explorer sequences, and the access explorer sequence consists of multiple access explorations. Access exploration consists of a preamble which is transmitted in the form of simple pilots before the transmission of an access channel message or

  user data for acquiring terminal synchronization, and an access message capsule comprising access information or user data.

  When a terminal transmits an access message or data to a common reverse link channel through the access attempt process, as previously described, first, it transmits an access scan to a predetermined power level. The power is at an adequate level not only to reduce an interference effect affecting other terminals transmitting data using a dedicated channel or via another reverse link channel, but also to reduce the time of processing by reducing the number of retransmissions. A terminal making an attempt at a first transmission of access exploration data controls the indication of whether or not access exploration is detected from a base station within a certain time (TA) . However, if a data transmission from the first access exploration fails, the terminal makes an attempt at a power level one predetermined level (PI) higher than that of the first access exploration after a time d 'random wait (RT). The terminal performs a continuous access exploration attempt including data transmission through the foregoing process. However, if the data transmission is not successful in a predetermined number of access explorations, after the completion of a particular access exploration sequence and after waiting for a random time20 ( RS), a terminal repeats a second access exploration sequence as the first access exploration. However, since the ALOHA method transmits data to the base with an inadequate power level in a conflict mode, an access exploration failure inevitably occurs due to an insufficient power level and a collision between transmitted data, resulting in unnecessary failed transmission. 30 There is a method using multiple preamble signatures to improve the possibility of acquiring a preamble. The preamble signature is a sequence consisting of multiple symbols to modulate a common spreading code used in a preamble for a common reverse link channel. Since an orthogonality is maintained between the preambles, a base station can simultaneously acquire multiple preambles having a different preamble signature. 5 While a preamble is a signal to obtain synchronization of a common channel with a reverse link, the longest preamble can acquire a more stable synchronization but is not efficient in terms of transmission efficiency. direct access having improved network efficiency by reducing unnecessary data transmission and interference signal and having an improved time delay characteristic by retransmitting preamble by preamble and climbing to an adequate power level faster , in which terminals select one of the available preamble signatures and one time slots20 available and transmit a preamble, a base station tries to acquire the preamble and broadcasts to

  all terminals know that the preambles are or are not acquired, and the terminals transmit data or retransmit a preamble depending on the result of the preamble acquisition.

  According to the present invention, when a terminal transmits a modulated preamble with a preamble signature, it randomly selects a preamble signature from a subset of 30 preamble signatures classified according to traffic characteristics to pass different data. in packets, effectively. Also, after a base station has acquired the preamble for all available preamble signatures, it informs all terminals of the preamble signature acquired via a common reverse link channel. Then, the terminal checks whether its own transmitted preamble is acquired or not, if the preamble is acquired, the terminal transmits user information data at the predefined time with a power level adequately estimated by the power level during of the preamble transmission. Otherwise, the terminal randomly selects an access time and a preamble signature, determines a power level increased by the predefined power step, compares a power level from a previous preamble, and retransmits a preamble. The invention also relates to a direct access device in which multiple terminals (100) transmit data to a base station (200) via a common reverse link channel using a multiple access method by code distribution, characterized in that the base station (200) acquires the preamble code transmitted from the multiple terminals (100) via a common reverse link channel for all the preamble signatures available , and transmits an acquisition indication signal, indicating whether or not the preamble signatures transmitted from the multiple terminals (100) are acquired, to the multiple terminals (100) via a common direct link channel ; and the multiple terminals (100) select their own preamble signatures from among the preamble signatures assigned to data characteristics to be transmitted, modulate, spread and transmit the preamble to the base station (200), receive the indication signal acquisition from base station 35 (200) via the common direct link channel 8, and, if the transmitted preamble signatures are acquired, the terminals (100) transmit the data, if this is not the case , the terminals (100) retransmit a preamble. In particular, this device can be characterized in that each terminal (100) comprises: first terminal determination means (110) for randomly selecting a preamble signature from among the available preamble signatures classified according to traffic characteristics and an access time slot to be transmitted, and a power level of determination of u preamble using a direct link path loss, an interference signal level from the base station (200) and the power level of the previous preamble if applicable; first terminal transmission means (120) for producing and transmitting a preamble having the determined preamble signature and a power level to the access time slot selected in the first determining means (110); first terminal processing means (170) active by the first terminal determining means (110) for formatting user information data to be transmitted; second terminal transmission means (180) for receiving the formatted user information signal from the first terminal processing means (170), for spreading and outputting the signal with the channel code corresponding to the signature of preamble; terminal selection means (130) for selecting either the data produced at the second terminal transmission means (180) or the preamble produced at the first terminal transmission means (120) according to the signal acquisition indication transmitted from the base station (200); second terminal processing means (140) for transforming the signal selected at the terminal selection means (130) into a high frequency (RF) signal and for transmitting it to the base station (200) via a wireless channel, and to transform an acquisition indication signal into a high frequency signal transmitted from the base station (200) into a baseband signal; terminal receiving means (150) for receiving the baseband acquisition indication signal from the second terminal processing means (140) and for verifying whether or not the transmitted preamble signature is acquired; and second terminal determining means (160) for validating and invalidating the first terminal determining means (110) according to the result verified at the terminal receiving means (150), and for outputting a signal to switch a switch terminal selection means (130). Alternatively, the first terminal determining means (110) may include: signature memory means (111) for receiving and storing information relating to a set of preamble signatures classified by a traffic characteristic transmitted from the station base (200) via a common channel 30 with direct connection; signature selection means (112) for classifying the data produced by considering traffic characteristics and demand conditions from the upper layer, and for randomly selecting a preamble signature from among the available preamble signatures corresponding to the traffic characteristic; time slot selection means (113) for selecting, randomly or deterministically, an access time slot when the preamble is transmitted; and power determining means (114) for determining the power of a transmission preamble by considering the interference signal level of the base station (200), the loss of direct link path, and the power level of the preamble previously transmitted. The first terminal transmission means (120) can advantageously transmit the preamble with the preamble signature and the power level to the transmission time slot, in the first terminal determination means (110) and by modulating the code d 'common sprawl by the signature of the preamble. The first terminal transmission means (120) can advantageously produce a complex band spread signal whose real value is the same as the imaginary value, using the selected preamble signature and the common spread code. terminal reception means (150) can advantageously receive the indication signal

  using a sequence corresponding to the transmitted preamble signature and a spreading code assigned to the common direct link channel30 for the transmission of acquisition indication.

  The second terminal determination means (160) can advantageously validate the first terminal determination means (110) and output a signal to connect the output of the first terminal transmission means (120) to the terminal selection means (130) , if the signal indicating positive acquisition or acquisition in function is received; otherwise, the second terminal determination means (160) invalidates the first terminal determination means (110), and connects the output of the second terminal transmission means (180) to the terminal selection means (130). Alternatively, the base station (200) includes: basic processing means (210) for receiving a high frequency signal transmitted from the terminal (100), and for transmitting a high frequency signal to the terminal (100 ); basic synchronization means (220) for receiving a preamble transmitted from the terminal (100) via a common reverse link channel from the basic processing means (210), and for carrying out an acquisition the preamble with all available preamble signatures; basic determination means (230) for verifying the acquisition, and for determining and outputting the acquired preamble signatures; basic transmission means (240) for producing multiple acquisition indication signals corresponding to the acquired preamble signatures input from the basic determination means (230), and for outputting the signal to the terminal (100) through the basic processing means (210); and basic transceiver means (250) for receiving multiple path time delay information obtained from the basic synchronization means (220), for producing a reverse spreading code using the information relating to the acquired preamble signature received from 12 from the basic determination means (230), for receiving the data transmitted from the terminal (100) via the common reverse link channel from the basic processing means5 ( 210), and to receive the processed data via demodulation and channel decoding. As a variant, the basic synchronization means (220) can then comprise: synchronization means for receiving the preamble transmitted from the terminal (100) via the common reverse link channel from the basic processing means (210), and to acquire preambles with all the available preamble signatures; means for outputting a time delay characteristic to cause all of the basic transceiver means (250) to identify a time delay characteristic corresponding to the acquired preamble signature, and for causing that the basic transmission-reception means (250) are ready to receive data to be transmitted at the predefined time if necessary; acquisition indication signal output means for informing the base determination means (230) that preamble signatures are acquired. Alternatively, the basic determination means (230) may include: means forming a spread spectrum signal to inform of a code

  spreading corresponding to the preamble signature entered from the basic synchronization means (220) to the transmission-reception means (250) and to ensure that the transmission means

  13 basic reception (250) are ready to receive data to be transmitted at a predefined time if necessary; and acquisition indication signal generator means for producing acquisition indication signals corresponding to only the preambles acquired and for outputting the signals to the basic transmission means (240). The basic transmission means (240) can advantageously transmit on-off signals to divide the available times into the number of available signatures and to assign each divided time to each available preamble signature, to transmit acquisition indication signals15 only on the divided times allocated to the acquired preamble signatures, and so as not to transmit any acquisition indication signal on the divided times allocated to the unearned preamble signatures. The basic transmission means (240) can advantageously transmit antipodal signals to divide the available times into the number of available signatures and to assign each divided time to each available preamble signature, to transmit positive acquisition indication signals for acquired preamble signatures and negative acquisition indication signals for unacquired preamble signatures on all divided times allocated to available preamble signatures. The basic transmission means (240) can advantageously transmit on signals -stop for

  assign an orthogonal code to a preamble signature and to position it as a symbol to be transmitted, and to transmit only an orthogonal code35 corresponding to the acquired preamble signature.

  The basic transmission means (240) can advantageously transmit antipodal signals to assign an orthogonal code to the preamble signature and to position it as a symbol, to transmit positive acquisition indication signals for preamble signatures acquired and

  negative acquisition indication signals for unacquired preamble signatures, all orthogonal codes being assigned to the available preamble signatures10.

  The basic transmission means (240) can transmit signals of any type so that the acquisition indication signals are orthogonal or antipodal to each other. Multiple terminals (100) can transmit data to a base station (200) via a common channel using a code division multiple access method, the method performing the following steps: in the multiple terminal (100), selection of one available preamble signatures corresponding to the traffic characteristics and an access time slot for transmitting a preamble, modulation and transmission of the preamble to the base station (200); in the base station (200), realization of acquisition of a preamble code of the preamble transmitted from the multiple terminals (100) via a common reverse link channel for all the preamble signatures available, transmission of a signal verifying whether or which preambles are acquired or not and determination of the preamble signatures acquired, production of acquisition indication signals corresponding to the preamble signatures acquired, and transmission of the signal to all the terminals35 (100) by l 'through a common direct link channel; and in the multiple terminals (100), reception of an acquisition indication signal of the preamble broadcast from the base station (200) to all the terminals (100), and, if the transmitted preamble is acquired , data transmission, if not, retransmission of a preamble. Each terminal (100) can possibly also perform the following steps: a first determination step for randomly selecting a preamble signature from among the preamble signatures classified according to traffic characteristics and an access time slot, and determination the power level of the preamble using a forward link loss, an interference signal level from the base station (200) and the power level of the previous preamble if applicable; a first transmission step for producing and transmitting a preamble with the determined preamble signature and the power level to the access time slot selected in the first determination step; a first processing step being active by the first determining step to format user information data to be transmitted; a second transmission step for receiving the formatted signal of user information from the first step of processing, spreading and outputting the signal with the channelization code corresponding to the preamble signature; a selection step for selecting either the data produced at the second transmission step, or the preamble produced at the first transmission step according to the acquisition indication signal 16 transmitted from the base station (200 ); a second processing step for transforming the signal selected at the selection step into a high frequency signal and for transmitting it to the base station (200) via a wireless channel, and transforming an acquisition indication signal in a high frequency signal transmitted from the base station (200) in a baseband signal; a reception step for receiving the baseband acquisition indication signal from the second processing step and checking whether the transmitted preamble signature has been acquired or not; and a second determination step to validate and invalidate the first determination step according to the result verified at the reception step, and output of a signal to switch the selection step.20 As a variant, the first step of determining may include the following steps: receiving and storing information regarding the set of preamble signatures classified by a traffic characteristic transmitted from the base station (200) via a common direct link channel; ranking the data produced by considering traffic characteristics and demand conditions from the upper layer, and random selection of a preamble signature from the available preamble signatures corresponding to the traffic characteristic; random or deterministic selection of an access time slot when the preamble is transmitted; and determining the power of a transmission preamble by considering a signal level

  interference from the base station (200), loss of direct link path, and the power level of the preamble previously transmitted if applicable.

  The first transmission step can advantageously transmit the preamble with the

  preamble signature and the power level at the transmission time slot in the first determination step and by modulating a common spreading code by the preamble signature.

  Advantageously, the first step of transmission produces a complex band spread signal whose

  actual value is the same as the imaginary value using the selected preamble signature and the common spreading code.

  Advantageously, the reception step receives the acquisition indication signal using a

  sequence corresponding to the preamble signature transmitted and a spreading code assigned to the common channel 20 with direct link for a transmission of acquisition indication.

  Advantageously, the second determination step validates the first determination step and outputs a signal to link the output of the first transmission step to the selection step, if the signal indicating positive acquisition or acquisition in

  function is received; otherwise, the second determination step invalidates the first determination step, and links the output of the second transmission step to the selection step.

  Alternatively, the base station (200) may further perform the following steps: a first step of receiving a high frequency signal transmitted from the terminal, and transmitting a high frequency signal to the terminal; a second step of receiving the preamble transmitted from the terminal via the common reverse link channel from the first step, and carrying out the acquisition of the preamble with all the preamble signatures available; a third step of verification of the acquisition, determination and output of the acquired preamble signatures; a fourth step of producing multiple acquisition indication signals corresponding to the acquired preamble signatures entered from the third step, and output of the signal to the terminal (100) via the first step; and a fifth step of receiving multiple path time delay information obtained from the second step, producing a reverse spreading code using the information regarding the acquired preamble signature received from the third step , reception of data transmitted from the terminal via the common reverse link channel from the first

  step, and reception of the data processed by channel modulation and decoding.

  Advantageously, the second step comprises the following steps: reception of the preamble transmitted from the terminal (100) via the common reverse link channel from the first step, and realization of the acquisition of a preamble with all 30 the preamble signatures available; instruction in the fifth step to identify a time delay characteristic corresponding to the acquired preamble signature, and instruction in the fifth step to be ready to receive data to be transmitted at a predefined time if necessary; and

  information at the third stage of which preamble signatures are acquired.

  Advantageously, the third step comprises the following steps: informing a spreading code corresponding to the preamble signature entered from the second step to the fifth step, and instructing the fifth step to be ready to receive data to be transmitted at a predefined time if necessary; and producing acquisition indication signals corresponding only to the preambles acquired and outputting the signals to the fourth step. Advantageously, the fourth step transmits any signals so that the indication signals

  are orthogonal or antipodal to each other.

  Advantageously, the fourth step produces and transmits the acquisition indication signal as a combination of a combined or selected format 20 comprising: an on-off signal format for dividing the available times into the number of available signatures and for assigning each divided time at each available preamble signature, for transmitting acquisition indication signals only over the divided times allocated to the acquired preamble signatures, and for transmitting no acquisition indication signal over the divided times allocated to the signatures unacquired preamble; 30 an antipodal signal format for dividing available time into the number of available signatures and for assigning each divided time to each available preamble signature, and for transmitting positive acquisition indication signals for signatures35 of acquired preamble and negative acquisition indication signals for unearned preamble signatures on all divided times allocated to available preamble signatures; an on-off signal format for assigning an orthogonal code to a preamble signature and for positioning it as a symbol to be transmitted, and for transmitting only an orthogonal code corresponding to the acquired preamble signature; and an antipodal signal format for assigning an orthogonal code to the preamble signature and for positioning it as a symbol, for transmitting positive acquisition indication signals for acquired preamble signatures and indication signals negative acquisition for unacquired preamble signatures15, all orthogonal codes

  being attributed to the available preamble signatures.

  Alternatively, the fourth step may be carried out by one of the methods comprising: a penetration method applied to a common channel with an anterior direct link; a method using a code orthogonal to the other common direct link channel; and

  a method using a code that is not orthogonal to the other common direct link channel.

  Advantageously, the base station (200) classifies data characteristics to be transmitted via a common reverse link channel into direct and packet access for transmitting short data, a channel reservation request for transmitting intermediate data, and a channel request requesting a dedicated channel allocation for transmitting a large continuous stream of data, allocates the preamble signatures according to the classified characteristics of the data to be transmitted, and transmits the information concerning the preamble signatures 21 allocated by the through a common direct link channel for all terminals to identify them. In the case where data having a multiple frame length is served by direct and packet access, the base station (200) can advantageously classify, in a secondary manner, the preamble signatures allocated to direct and packet access according to the length of the data. 10 In the event that data is served by the channel reservation request, the method can advantageously be carried out by the following steps: random selection by the terminal (100) of one of the preamble signatures allocated for a channel reservation and transmission of a preamble; realization by the base station (200) of a preamble code acquisition transmitted from the terminals and information to all the terminals (100) of the preamble signature acquired via a common direct link channel; if the terminal (100) receives an acquisition indication signal for a successful preamble acquisition, random selection by the terminal (100) of one of the preamble signatures allocated for a channel reservation, determination of a slot access time, and retransmission of a preamble; if the terminal (100) receives an acquisition indication signal for a failed preamble acquisition, transmission by the terminal (100) of the data for a reservation request and attempt of a channel reservation after transmission of data for a channel reservation request; informing the corresponding terminals (100) by the base station (200) of a channel reservation, a reserved time, a spreading code, and a maximum admissible transmission speed, if reception is successful data transmitted for a channel reservation request from a terminal (100); transmission of data by the corresponding terminal (100) using the spreading code over the time reserved in the range of maximum admissible transmission speeds, and production of a power control by means of a power control command via a dedicated or common direct link channel; and transmission by the terminal of information indicating the completion of a data transmission with data during the transmission of a final frame, and cancellation of the channel reservation. Alternatively, the terminal (100) can transmit data to modify the reservation condition of

  channel with current transmission data, in parallel, in the same way as direct and packet access and the channel reservation request during reservation, or multiplex and transmit the data with the previously reserved data.

  Other characteristics and advantages of the invention will emerge more clearly on reading

  the description which will follow when taken in conjunction with the appended drawings, in which:

  FIG. 1 is a diagram showing a data transmission of an ALOHA method using a common reverse link channel according to a code division multiple access method according to the prior art; Figure 2 is a network configuration diagram for applying the present invention; FIG. 3A is a functional diagram of a terminal and of a base station at the level of a direct access device of a common channel with reverse link according to a multiple access method by code distribution according to the present invention; Figure 3B is a block diagram of a first terminal determining device of Figure 3A; FIG. 4 is a diagram showing operations between a base station and a terminal of a device according to the present invention; Figure 5 is an access flow diagram of a terminal according to the present invention; FIG. 6 is an access flow diagram of a base station according to the present invention; FIG. 7 is a diagram showing an example of operation of a common channel device with reverse link according to a code division multiple access method according to the present invention; Figure 8 is a diagram showing an example of an interference signal level of a

  common reverse link channel according to a code division multiple access method according to the present invention.

  To achieve the objective, the present invention provides a direct access device in which multiple terminals transmit data to a base station via a common reverse link channel using code division multiple access , in which the base station acquires a preamble transmitted from the multiple terminals via a common reverse link channel for all the preamble signatures available, and transmits a signal, indicating whether the signature of the preamble transmitted from the multiple terminals is acquired or not, to the terminals via a common direct link channel; and the multiple terminals randomly select the preamble signature classified by the 24 data characteristics to transmit and modulate the preamble, receive the signal indicating the acquisition of an indication transmitted from the base station via the channel common direct link. If the preamble is acquired, the terminal transmits user information data at the predefined time with a

  power level adequately estimated by the power level when the preamble is transmitted, otherwise, it retransmits a preamble having a preamble signature10 randomly selected to an access time slot.

  In the rest of the document, we will describe the preferred embodiment.

  Figure 2 is a configuration diagram of a

  network to apply the present invention.

  The network includes a terminal 100 for producing data and for transmitting a preamble (s) via a common reverse link channel, a base station 200 for acquiring code 20 using the transmitted preamble from terminal 100 via a common reverse link channel, to indicate to terminal 100 whether or not the preamble is acquired, to receive user information data corresponding to a terminal, and for s '' interface to an upper layer protocol; a CDMA network 300 to manage the multiple base stations 200 and 210 and to interface with other networks; a public switched telephone network (PSTN) 400 connected to the CDMA network 300 to connect the terminal 100 to a subscriber to the usual cable telephone; an Internet 500 connected to the CDMA 300 network to connect the

  Internet terminal 100; and a public switched data network (PSDN) 600 connected to the CDMA network 300 to connect the terminal 100 to the data server supported by a data service.

  A device for direct access to a common reverse link channel according to the present invention, on the network, further comprises means for transmitting the acquisition indication signal in a base station, means for receiving the acquisition indication signal and determination means for transmission in a terminal. The transmission means in the base station transmit an acquisition indication signal indicating to all the terminals whether the transmitted preamble signature has been acquired, after a preamble code acquisition has been carried out.

  for all preamble signatures available via a common reverse link channel. The reception means in the terminal receive the acquisition indication signal from the base station via a common direct link channel.

  And the determining means determines whether the user information data is to be transmitted or whether the preamble is to be transmitted again according to the acquisition indication signal. If the preamble signature is indicated as acquired, the terminal

  transmits user information data, otherwise, it again transmits a preamble having a randomly selected preamble signature and an increased power level to a newly selected access time slot.

  Figure 3A is a block diagram of a terminal and a base station at an access device

  reverse link common channel direct according to a code division multiple access method according to the present invention.

  The terminal 100 includes a first terminal determination device 110 for randomly selecting a preamble signature from among available preamble signatures classified according to traffic characteristics and an access time slot to be transmitted, and for determining a level power of the preamble using the direct link path loss, the interference signal level from the base station; a first terminal transmission device 120 for transmitting a preamble having the determined preamble signature and a power level to the access time slot selected in the first terminal determination device 110; a first terminal processing device 170 active by the first terminal determining device 110 for formatting user information data to be transmitted; a second terminal transmission device 180 for receiving the formatted user information signal from the first terminal processing device 170, for spreading and outputting the signal with the channelization code corresponding to the preamble signature; a terminal selection device 13020 for selecting either the data produced at the second terminal transmission device 180, or the preamble produced at the first terminal transmission device 120 according to the acquisition indication signal transmitted from from base station 25,200; a second terminal processing device 140 for transforming the signal selected at the level of the selection device 130 into a high frequency (RF) signal and for transmitting it to the base station 200 via a wireless channel, and to transform an acquisition indication signal into a high frequency signal transmitted from the base station 200 into a baseband signal; a terminal receiving device 150 for receiving the baseband acquisition indication signal from the second terminal processing device 140 and 27 to verify whether or not the transmitted preamble signature is acquired; and a second terminal determining device 160 for validating and invalidating the first terminal determining device 110 according to the result verified at the terminal receiving device 150, and for outputting a signal for switching a switch of the terminal selecting device 130. As described in FIG. 3, the first terminal determination device 110 includes a signature memory 111 for receiving and storing information relating to a set of preamble signatures classified by a characteristic of traffic transmitted from the station. base via a common direct link channel; a signature selection device 112 for classifying the data produced by considering the traffic characteristics and demand conditions originating from the upper layer, and for randomly selecting a preamble signature from the available preamble signatures corresponding to the characteristic traffic; a time slot selection device 113 for randomly or deterministically selecting an access time slot when the preamble is transmitted; and a power determining device 114 for determining the power of a transmission preamble by considering the interference signal level of the base station, the forward link loss, and the power level of the preamble previously transmitted. The power determining device 114 is configured to determine the power level by considering a level of base station interference signal transmitted from the base station via a common direct link channel, 35 the loss of direct link path, of a step 28 of predefined power increase, and of the power level of the preamble previously transmitted. The first terminal transmission device transmits the preamble using the access time slot, the preamble signature, and the power level determined at the first terminal determination device 110 and by modulating the common spreading code by the preamble signature, and produces a complex spread signal whose actual value is the same as the imaginary value, using the selected preamble signature and the common spread code. The terminal reception device 150 receives an acquisition indication signal using the same signature as the transmitted preamble signature and a code used for the transmission of acquisition indication in a direct link. Also, the second terminal determination device 160 validates the first terminal determination device 110 and outputs a signal to connect the output of the first terminal transmission device 120 to the terminal selection device 130, if the indication signal d acquisition indicates an acquisition of the preamble signature transmitted; otherwise, the determination device 160 invalidates the first terminal determination device 110, and connects the output of the second terminal transmission device 180 to the terminal selection device 130. The base station 200 comprises a basic processing device 210 for receiving a high frequency signal transmitted from the terminal 100, and for transmitting a high frequency signal to the terminal 100; a basic synchronization device 220 for receiving a preamble transmitted from the terminal 35 100 via a common channel with reverse link 29 from the basic processing device 210, and for carrying out an acquisition of the preamble with all the preamble signatures available; a basic determination device 230 for verifying the acquisition, and for determining and outputting the acquired preamble signatures; a basic transmission device 240 for producing multiple acquisition indication signals corresponding to the acquired preamble signatures entered from the basic determination device 230, and for outputting the signal to the terminal 100 via the device basic salary 210; and a basic transceiver device 250 for receiving multiple path time delay information 15 obtained from the basic synchronization device 220, for producing a reverse spreading code using the information about the preamble signature received received from the basic determination device 230, to receive the data transmitted from the terminal 100 via the common reverse link channel from the basic processing device 210, and to receive the data processed by the channel modulation and demodulation. 25 The basic synchronization device 220 comprises a synchronization device for receiving the preamble transmitted from the terminal 100 via the common reverse link channel from the basic processing device 210, and for carrying out the preamble acquisition with all the signatures preamble is available; a time delay characteristic output unit for causing all the basic transceiver devices 250 to identify a time delay characteristic corresponding to the acquired preamble signature,

  and to make sure that the transmitting devices-

  basic reception 250 are ready to receive data to be transmitted at the predefined time if necessary; and an acquisition indication signal output unit for informing the base determination device 230 that preamble signatures are acquired. The basic determination device 230 comprises a generator of a spread spectrum signal to inform of a spread code corresponding to the preamble signature entered from the basic synchronization device 220 destined for the transmit-receive 250 and to cause the base transceiver 250 to be ready to receive data to be transmitted at a predefined time if applicable, and a generator of acquisition indication signals to produce acquisition indication signals corresponding only to the preambles acquired and to output the signals intended for the basic transmission device 240.20 The basic transmission device 240 is configured to transmit the acquisition indication signal on the basis of one of the signal formats comprising: a stop signal format n 1 for dividing the available times into the number of available signatures25, for attrib uer each divided time at each available preamble signature, to transmit acquisition indication signals only on the divided times allocated to the preamble signatures acquired, and to transmit no acquisition indication signal30 on the divided times allocated unearned preamble signatures; an antipodal signal format n 2 for dividing the available times into the number of available signatures, for allocating each divided time to each available preamble signature, and for transmitting positive acquisition indication signals 31 for acquired preamble signatures and negative acquisition indication signals for preamble signatures not acquired over all the divided times allocated to the 5 preamble signatures available; an on-off signal format n 3 for assigning an orthogonal code to a preamble signature and for positioning it as a symbol to be transmitted, and for transmitting only an orthogonal code corresponding to the acquired preamble signature; and a No. 4 antipodal signal format for assigning an orthogonal code to the preamble signature and for positioning it as a symbol, for transmitting positive acquisition indication signals for acquired preamble signatures and indication signals negative acquisition for unacquired preamble signatures, all codes

  orthogonal being assigned to the available preamble signatures. Also, the additional signal formats can be used by combining the four signal formats in a hybrid fashion.

  The system for transmitting the acquisition indication signal selects and transmits one of the methods comprising a penetration method applied to an earlier direct link common channel, a method using a code orthogonal to another common link channel direct, and a method using a code not orthogonal to another common direct link channel. Also, base station 200 distinguishes between characteristics of data to be transmitted via a common reverse link channel into packet access to transmit short data, a channel reservation request to transmit data intermediaries, and a channel request requesting 35 a dedicated channel allocation to transmit a large

  32 continuous stream of data such as voice data.

  And, the base station 200 classifies all the preamble signatures available according to the characteristics of the data to be transmitted, broadcasts them via a common direct link channel for all the terminals to identify them.

  To access the packet for base station 200, the terminal 100 transmits a preamble, one of the preamble signatures being classified by data characteristics via packet access such as its length and speed. transmission, reviews its acquisition indication transmitted from base station 200 and determines whether it retransmits a preamble or if it transmits user information data. 15 If it is determined that the user information data are transmitted, the terminal 100 transmits

  continuously one frame or multiple frames in accordance with a frame structure, and again performs an operation for packet access with regard to failed frames of the transmitted frames.

  For the channel reservation request, the terminal randomly selects one of the preamble signatures assigned for a channel reservation request and transmits a preamble identical to that of packet access, and the base station 200 performs the acquisition of the preamble transmitted from the terminal 100 and informs all the terminals via a common direct link channel that preambles are acquired. When none or a negative acquisition indication is indicated at the terminal 100, it randomly selects one of the preamble signatures allocated for a channel reservation, determines an access time slot, and retransmits a preamble. Furthermore, when the terminal 100 transmits the preamble whose signature is acquired, it transmits the user information data for a reservation request and performs a channel reservation attempt by transmitting data for a channel reservation. And, the base station 200 informs the corresponding terminals of a channel reservation or not, of a reserved time and of a spreading code, and of a transmission speed, by using a common channel with direct link. , after precise reception of the data transmitted for a channel reservation from a terminal. Then, the corresponding terminals transmit data to be transmitted using the reserved time, the spreading code, and the transmission speed, perform a power control using a power control instruction to be transmitted to a direct link channel, and transmit information indicating the completion of data transmission by data upon transmission of a final frame and cancel the reservation.20 To change a channel reservation condition during the reservation, there is a method of that the terminal 100 transmits data to modify the condition of channel reservation by transmission data in the same operation for the access by packets and the channel reservation request. The other method is that the terminal 100 multiplexes data

  to modify the channel reservation conditions by the user information data and then transmits it. In both methods, base station 20030 should transmit information related to acceptance or rejection.

  We will describe the implementation of a device of a common channel with a reverse link according to a multiple access method by code distribution according to the invention. FIG. 4 is a diagram representing 34 operations between a base and a terminal of a device according to the present invention. As shown in FIG. 4, once data to be transmitted occurs, a terminal 100 transmits a preamble to a base station 200, and the base station 200 performs a preamble code acquisition and transmits an indication signal d acquisition of the preamble code acquisition to all the terminals 100. According to the above, each terminal 100 checks the acquisition indication signals, and when the transmitted preamble is not acquired, the terminal 100 retransmits a preamble; otherwise, it transmits user information data. Then, the base station 200 receiving data transmits an acknowledgment signal 15 of the user information data to the terminal 100 after the reception and error checking of the user information data. The time for not acquiring the preamble is called free time (IT) .20 The implementation of a terminal is described in FIG. 5. As described by means of FIG. 5, when data to be transmitted are produced (S101), the terminal 100 selects one of the available preamble signatures corresponding to the traffic characteristics and an access time slot for transmitting a preamble (S102), and performs a determination step (S103) which determines the power level of a transmission preamble using direct link path loss, information regarding an interference signal level transmitted from a base station 200. Then, the terminal 100 produces

  and transmits a preamble, with the preamble signature randomly selected and the determined power level, to the randomly selected access time slot (S104).

  After that, the terminal 100 receives an indication signal of acquisition of the preamble broadcast.

  from base station 200 to all terminals 100 (S105) and checks whether or not its own transmitted preamble signature is acquired (S106).

  If the transmitted preamble is acquired during the step of receiving the acquisition indication signal, the terminal 100 formats the user information data in a predefined form, performs a step of transmitting data to select a message. or a preamble, for spreading according to a specific spreading code corresponding to the preamble signature, and for transmitting it (S107). However, if the preamble transmitted is not acquired during the step of receiving the acquisition indication signal, the terminal 100 performs a retransmission step for

  repeating the steps starting with the step of determining transmission sources such as a preamble signature, an access time slot and the power level, and to retransmit a preamble (S108).

  On the other hand, as described in FIG. 6, the base station 200 controls the transmission of the acquisition indication signal. First, base station 200 receives a high frequency signal from the terminal (S201), and performs a preamble code acquisition step to try to acquire synchronization for preambles with all available preamble signatures ( S202) .30 Next, the base station 200 checks whether or not the preambles are acquired or not and determines a signature

  preamble signal (S203), produces acquisition indication signals corresponding to the acquired preamble signature, and transmits the signal to all terminals (S204).

  Then, the base station 200 obtains a time delay and information on the fading phase information of the estimated multiple path obtained at the acquisition of preamble code, produces a spreading code using the information of the acquired preamble signature and is ready to receive (S205). And base station 200 receives

  data transmitted from the terminal via a common reverse link channel, and receives user information data via demodulation and channel decoding (S206).

  We will now describe the operations in more detail. When a first terminal determination device 110 is validated from the outside, the first terminal determination device 110 randomly selects a particular preamble signature from a set of preamble signatures classified by a characteristic of data to be transmitted , and, at the same time, randomly selects an access time slot. Then, a first terminal transmission device 120 spreads the preamble signature using a common spreading code, produces a preamble to be transmitted and transmits it to the selected transmission time slot. At this time, a terminal selection device 130 is connected to the first terminal transmission device 120, takes out the preamble for a second terminal processing device 140, and transmits it to the base station 200.30 Therefore, in the base 200, a base station processing device 210 receives the preamble transmitted from the terminal 100 and outputs the preamble to a basic synchronization device 220. The basic synchronization device 22035 performs a preamble code acquisition with all 37 the available preamble signatures, and outputs the information for the acquisition or not to a basic determination device 230. Then, the basic determination device 230 receives the information5 concerning each preamble signature from the synchronization device of base 220 and determines the acquired preamble signatures, then outputs it to the transmission device base 240 and to the basic transmit-receive device 250. The base transmission device 240 receives an acquired preamble signature, produces a signal corresponding to the acquired preamble signature and outputs the signal to the terminal 100 using a common channel with direct link via the basic processing device 210. At the same time, the basic transmission-reception device 250 receives the

  preamble signatures acquired from the basic determination device 230 and is ready to receive the data transmitted from the terminal 20 100 using the spreading codes corresponding to the preamble signature acquired.

  On the other hand, the terminal reception device 150 receives the acquisition indication signal transmitted from the base station 200 via a common direct link channel by means of the second data processing device. terminal 140, checks whether or not the transmitted preamble is acquired, and outputs the result of the verification to the second terminal determination device 160.30 At this time, if the second terminal determination device 160 verifies a successful acquisition of the transmitted preamble, the determining device 160 invalidates the first terminal determining device 110 and the first terminal transmitting device 120, and the second terminal transmitting device 180 spreads out the user information data formatted by the first processing device of terminal 170 with a spread corresponding to the preamble signature transmitted, and outputs the signal to the disp terminal selection device 130. Next, the terminal selection device 130 receives an indication signal for acquiring a preamble signature from the second terminal determination device 160, 10 closes a switch to the output of the terminal. second terminal transmitting device 180, and transmits the signal to the base station 200 via the second terminal processing device 140. Then, the transmitted data is entered into the basic transmitting / receiving device 250 by through the basic processing device 210, and the device

  basic transmit-receive 250 retrieves data by means of a demodulation and decoding process using a predefined spreading code through a common reverse link channel.

  On the other hand, if the second terminal determination device 160 verifies a non-acquisition of the transmitted preamble, the first terminal determination device 110 and the first terminal transmission device 120 are validated. Namely, the first terminal determination device 110

  randomly reselects a particular signature from a set of preamble signatures, at the same time, randomly selects 30 or deterministically an access time slot.

  Like the previous transmission of the initial preamble, the first terminal transmission device 120 spreads out the determined preamble signature using a common spreading code and produces a preamble to be transmitted, then transmits the preamble to the access time slot. selected. And, the terminal selection device 130 is connected to the first terminal transmission device 120, takes out the preamble to the second processing device of terminal 140 and transmits the preamble to the base station 200. And, said operations are repeated by the limited number of repetitions, which is a system setting

  depending on system loads, balances of traffic to be served and other system conditions.

  FIG. 7 is a diagram showing an example of implementation of a common channel device with reverse link according to a code division multiple access method according to the present invention. As described in FIG. 7, firstly, it is assumed that a frame period is 10 ms, that a time slot is 1.25 ms, that a frame period has 8 time slots d access and a preamble occupies i ms. Thus, an access time slot is constituted by a preamble duration of 1 ms long and by a free time of 0.25 ms. There is also the

  access time slot at base station 200, consisting of an acquisition indication signal duration of 1 ms in length and a free time of 0.25 ms.

  Also, we consider an example of 2 preamble signatures and short data available in a particular frame duration for the sake of clarity. It is assumed that three of the terminals, having data to be transmitted before a first access time slot start point (To), randomly select any preamble signatures and the same access time slot. However, no preamble is acquired in base station 200, since there is no preamble having a power level

sufficient.

  At this time, the base station 200 transmits only a negative acquisition indication signal according to signal formats 2 and n 4, while it transmits a non-acquisition indication signal according to signal formats n 1 and n 3. Therefore, each terminal

  should retransmit each preamble with a randomly selected preamble signature and with the power level increased at a randomly selected or predefined access time slot.

  When terminals determine a sufficient power level via a power servo and transmit each preamble having a different preamble signature to the next access time slot T1, the totality of the two preambles is successfully acquired and acquisition indication in operation or positive signals are received at all terminals. Thus, the terminals transmit each user information data item 20 ms long to an access time slot T2. Of course, the access time for a data transmission can be extended to T3 or T4. At time slot T2, there is a case where two terminals transmit preambles with an identical preamble signature and the base station successfully acquires preamble code synchronization. Thus, two terminals receive a functional or positive acquisition indication signal corresponding to its own preamble signature and transmit their user information data at the predefined time. In this case, if all the power levels of the acquired preambles are sufficient to effect the acquisition of preamble code in the base station, the base station cannot receive any user information data successfully being 41 since the receiving device combines multi-path signals from different user information data. However, if only one preamble has a power level sufficient for the receiving device and the other not, the receiving device in the base station will combine the signals to

  multiple paths from only particular user information data with sufficient power level, then it is likely to demodulate and decode user information data successfully.

  Fig. 8 is a diagram showing an example of an interference signal level of a device

  common reverse link channel according to a code access multiple access method according to the present invention.

  In FIG. 8, a solid line indicates a level of interference signal from a device for direct access to a common channel with an anterior reverse link, a dashed line indicates a level of interference signal from a device for direct access of a

  common reverse link channel according to the present invention, and oblique portions indicate a decreasing amount of an interference signal level of a device according to the present invention compared to the prior art.

  As described in FIG. 8, the device for direct access of a common reverse link channel according to the present invention reduces a level of interference signal and increases the overall acceptance capacity by eliminating any transmission of

  lots of unnecessary data, minimizes an effect on users using another channel, and transmits data faster because of retransmission35 preamble by preamble.

  In the remainder of the document, a short data transmission service of variable length will be described using an operation similar to the previous operation. Since a dedicated channel or a reservation request is required in the case of a data length exceeding a predetermined level, a data length which is accepted by the direct access method will be limited to several times a unit weft. Also, the types of data that can be accepted by the direct access process are

also limited.

  For example, if the direct access method can accept data up to 4 times the length of a frame, the terminal should request a dedicated channel allocation or a reservation channel for data the length of which exceeds 4 times a frame. At this time, firstly, a base station classifies a preamble signature allocated for packet access by data lengths and informs all the terminals thereof. The classification makes it easy to dynamically assign preamble signatures by considering traffic balances with data lengths that are too different.25 And, when the terminals transmit data using a common reverse link channel, they determine characteristics data traffic such as the length and transmission speed of a data transmission. If terminals 30 transmit data by a direct access method and a device according to the present invention, they transmit a preamble with preamble signatures and then they transmit the message signal including the data according to the acquisition indication. . If terminals transmit data 43 via a dedicated channel or a reservation channel, they transmit a preamble with preamble signatures and then transmit the message signal requesting a dedicated channel or a reservation channel according to the acquisition indication signal. For example, if terminals transmit ms data via a direct access method and a device, they transmit a preamble with one of the preamble signatures assigned for 40 ms data, and configure four 10 ms frames and transmit the frames continuously. And, if one of the frames transmitted continuously fails to be transmitted, only one is retransmitted. At this time, terminals can select a new preamble signature assigned for data characteristics to retransmit in the same manner as the previous method and transmit a preamble and a message signal. Next, we will describe an operation requesting a channel reservation using a common reverse link channel, when a terminal needs to reserve a channel temporarily to transmit data of intermediate length. First, the terminal 100 transmits information to request a channel reservation and an identification number of the terminal by the direct access method according to the present invention. When the terminal 100 transmits direct access, it selects one of the preamble signatures assigned for a channel reservation and transmits a preamble, and receives an acquisition indication signal for a preamble code acquisition from the base station 200 and transmits the data requesting a channel reservation. Since the data for a channel reservation can generally be accommodated 44 in a frame, the terminal 100 performs a transmission after the reception of a positive acquisition signal or of acquisition in function function coming from of the base station 200. Thus, the base station finds the length of data requested for a channel reservation and informs the terminal 100 of the status of the reservation request. That is, once the base station 200 precisely receives the data for a channel reservation, it informs the corresponding terminals of the channel reservation or not, of the time reserved, and of the spreading code. , and the maximum allowable transmission speed, and the receiving terminals transmit data within the range of maximum allowable transmission speeds using the time reserved spreading code. The base station 200 transmits a power control command signal using a dedicated or common direct link channel to a reserved terminal, it then performs a power control. When a terminal intends to modify the channel reservation conditions during a channel reservation, it transmits data concerning the channel reservation conditions to be modified according to the same method as the method transmitting a preamble for an initial channel reservation. Also, it is possible to multiplex the data concerning the channel reservation conditions to be modified with the current messages to be transmitted when the current transmission speed is lower than the maximum admissible transmission speed. And, when the channel reservation is completed, the terminal overlays

  the completion information on a predefined field of the latter and transmits it to the base station 200. Then, the base station 200 releases the reserved channel and the time reserved and informs all the terminals thereof.

  The intermediate length data channel reservation method will be used in an application domain such as voice service. On the other hand, when transmission data is long and a dedicated channel is requested to serve a voice signal, a method similar to that used when requesting a channel reservation is used. First, a terminal randomly selects one of the preamble signatures assigned10 for a dedicated channel request and transmits a preamble, receives an acquisition indication signal for a preamble code acquisition from the base station 200 and transmits data for a dedicated channel request. Then, the terminal transmits and receives the data using the dedicated channel after being informed whether or not an allocated dedicated channel and a spreading code have come from the base station 200. As an alternative to the request of previous channel reservation, a terminal can transmit data without frame length limit, and power servo can be easily achieved because one or more dedicated channels are allocated both for a forward link and for a link in the opposite direction. As previously described, the present invention is capable of using a variable type

  of a common reverse link channel such as a channel request for dedicated channel allocation, packet access for transmitting short data, intermediate data, classifying the preamble signature according to the characteristics of the data.

  Also, the invention is capable of improving the efficiency of a network by reducing the transmission of unnecessary data and interference signals, of rapidly approaching an adequate power level by retransmission preamble by preamble, and

  to obtain a good time delay characteristic.

  Although the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be readily understood by those skilled in the art that modifications in form and in details can be made without go out of mind or out of

field of the invention.

Claims (32)

  1. Device for direct access in which multiple terminals (100) transmit data to a base station (200) via a common reverse link channel using a code division multiple access method, characterized in that the base station (200) acquires a preamble code transmitted from the multiple terminals (100) via a common reverse link channel for all available preamble signatures, and transmits a acquisition indication signal, indicating whether the preamble signatures transmitted from the multiple terminals (100) are acquired or not, to the multiple terminals (100) via a common direct link channel; and the multiple terminals (100) select their own preamble signatures from among the preamble signatures assigned to data characteristics to be transmitted, modulate, spread and transmit the preamble to the base station (200), receive the indication signal acquisition from the base station (200) via the common direct link channel, and, if the transmitted preamble signatures are acquired, the terminals (100) transmit the data, if this is not the case, the terminals (100) retransmit a preamble. 2. Device according to claim 1, characterized in that each terminal (100) comprises: first terminal determination means (110) for randomly selecting a preamble signature from among the available preamble signatures classified according to traffic characteristics and an access time slot to be transmitted, and a 48 power level of preamble determination using direct link path loss, an interference signal level from the base station (200) and the level of power of the previous preamble5 if applicable; first terminal transmission means (120) for producing and transmitting a preamble having the determined preamble signature and a power level to the access time slot selected in the first determining means (110); first terminal processing means (170) active by the first terminal determining means (110) for formatting user information data to be transmitted; second terminal transmitting means (180) for receiving the signal formatted user information from the first terminal processing means (170), to spread and output the signal with the channel code corresponding to the preamble signature; terminal selection means (130) for selecting either the data produced at the second terminal transmission means (180) or the preamble produced at the first terminal transmission means (120) according to the indication signal acquisition transmitted from the base station (200); second terminal processing means (140) for transforming the signal selected at the terminal selection means (130) into a high frequency (RF) signal and for transmitting it to the base station (200) via a wireless channel, and to transform an acquisition indication signal into a high frequency signal transmitted from the base station (200) into a baseband signal; terminal receiving means (150) for receiving the baseband acquisition indication signal from the second terminal processing means (140) and for checking whether the transmitted preamble signature is acquired or not; and second terminal determining means (160) for validating and invalidating the first terminal determining means (110) according to the verified result   at the terminal receiving means (150), and10 for outputting a signal to switch a switch of the terminal selecting means (130).   3. Device according to claim 2, characterized in that the first terminal determination means (110) comprise: signature memory means (111) for receiving and storing information relating to a set of preamble signatures classified by a traffic characteristic transmitted from the base station (200) via a common direct link channel20; signature selection means (112) for classifying the data produced by considering traffic characteristics and demand conditions from the upper layer, and for randomly selecting a preamble signature from among the available preamble signatures corresponding to the traffic characteristic; time slot selection means (113) for selecting, randomly or deterministically, an access time slot when the preamble is transmitted; and power determining means (114) for determining the power of a transmission preamble by considering the interference signal level of the base station (200), the loss of direct link path, and the power level of the preamble previously transmitted. 4. Device according to claim 2, characterized in that the first terminal transmission means (120) transmit the preamble with the preamble signature and the power level to the transmission time slot, in the first means for determining terminal (110) and modulating the common spreading code by the preamble signature. 5. Device according to claim 4, characterized in that the first transmission means   terminals (120) produce a complex band spread signal whose actual value is the same as the imaginary value, using the selected preamble signature and the common spread code.   6. Device according to claim 2, characterized in that the terminal reception means (150) receive the acquisition indication signal using a sequence corresponding to the transmitted preamble signature and a spreading code assigned to the channel common with direct link for the transmission of acquisition indication. 7. Device according to claim 2, in which the second terminal determination means (160) validate the first terminal determination means (110) and output a signal to connect the output of the first terminal transmission means (120) to terminal selection means (130), if the signal of indication of positive acquisition or of acquisition in function is received; otherwise, the second terminal determining means (160) invalidates the first   terminal determining means (110), and connecting the output of the second terminal transmitting means (180) to the terminal selecting means (130).   8. Device according to claim 1, 51 characterized in that the base station (200) comprises: basic processing means (210) for receiving a high frequency signal transmitted from the terminal (100), and for transmitting a high frequency signal at the terminal (100); basic synchronization means (220) for receiving a preamble transmitted from the terminal (100) via a common reverse link channel from the basic processing means (210), and for carrying out an acquisition the preamble with all available preamble signatures; basic determination means (230) for verifying the acquisition, and for determining and outputting the acquired preamble signatures; basic transmission means (240) for producing multiple acquisition indication signals corresponding to the signatures acquired preamble inputs from the base determination means (230), and for outputting the signal to the terminal (100) via the base processing means (210); and base transceiver means (250) for receiving multiple path time delay information obtained from the base synchronization means (220), for producing a reverse spread code using the information relating to the acquired preamble signature received from the basic determination means (230), to receive the data transmitted from the terminal (100) via the common reverse link channel from the basic processing means (210 ), and to receive the processed data via demodulation and channel decoding. 35 9. Device according to claim 8, 52 characterized in that the basic synchronization means (220) comprise: synchronization means for receiving the preamble transmitted from the terminal (100) via the common reverse link channel from the basic processing means (210), and for acquiring preambles with all the preamble signatures available; means for outputting a time delay characteristic to cause all of the basic transceiver means (250) to identify a time delay characteristic corresponding to the acquired preamble signature, and for causing that the basic transmission-reception means (250) are ready to receive data to be transmitted at the predefined time if necessary; acquisition indication signal output means for informing the determination means   basic (230) that preamble signatures are acquired.   10. Device according to claim 8, characterized in that the basic determination means (230) comprise: means forming a generator of a spread spectrum signal for informing of a spread code corresponding to the signature of preamble   input from the basic synchronization means (220) to the transceiver means (250) and to ensure that the transceiver means   basic reception (250) are ready to receive data to be transmitted at a predefined time if necessary; and acquisition indication signal generator means for producing acquisition indication signals corresponding to only the 53 preambles acquired and for outputting the signals to the basic transmission means (240). 11. Device according to claim 8, characterized in that the basic transmission means (240) transmit on-off signals to divide the available times into the number of available signatures and to assign each divided time to each available preamble signature, to transmit acquisition indication signals only on the divided times allocated to the acquired preamble signatures, and to transmit no acquisition indication signals on the divided times allocated to the unearned preamble signatures. 12. Device according to claim 8, characterized in that the basic transmission means (240) transmit antipodal signals to divide the available times into the number of available signatures and to assign each divided time to each available preamble signature, to transmit positive acquisition indication signals for acquired preamble signatures and negative acquisition indication signals for unacquired preamble signatures on all divided times allocated to available preamble signatures. 13. Device according to claim 8, characterized in that the basic transmission means (240) transmit on-off signals to assign an orthogonal code to a preamble signature   and to position it as a symbol to be transmitted, and to transmit only an orthogonal code corresponding to the acquired preamble signature.   14. Device according to claim 8, characterized in that the basic transmission means (240) transmit antipodal signals for assigning an orthogonal code to the preamble signature and for positioning it as a symbol, for transmitting signals positive acquisition indication for acquired preamble signatures and negative acquisition indication signals for unacquired preamble signatures5, all orthogonal codes   being attributed to the available preamble signatures.   15. Device according to claim 8, characterized in that the basic transmission means (240) transmit signals of any type so that   the acquisition indication signals are orthogonal or antipodal with respect to each other.   16. Direct access method characterized in that multiple terminals (100) transmit data to a base station (200) via a common channel using a code division multiple access method, the method performing the following steps: in the multiple terminal (100), selection of one of the available preamble signatures corresponding to the traffic characteristics and of an access time slot for transmitting a preamble, modulation and transmission of the preamble to the base station (200); in the base station (200), carrying out a preamble code acquisition of the preamble transmitted from the multiple terminals (100) via a common reverse link channel for all the preamble signatures available, transmission of a signal verifying whether or which preambles are acquired or not and determination of the signatures of the acquired preamble, production of acquisition indication signals corresponding to the preamble signatures acquired, and transmission of the signal to all the terminals (100) by the 'through a common direct link channel; and in the multiple terminals (100), reception of an acquisition indication signal of the preamble broadcast in   from the base station (200) to all the terminals (100), and, if the transmitted preamble is acquired, data transmission, if this is not the case, retransmission of a preamble.   17. Method according to claim 16, characterized in that each terminal (100) additionally performs the following steps: a first determination step for randomly selecting a preamble signature from among the preamble signatures classified according to traffic characteristics and an access time slot, and determination of the power level of the preamble using direct link path loss, an interference signal level from the base station (200) and the power level of the previous preamble If it's happened; a first transmission step for producing and transmitting a preamble with the determined preamble signature and the power level to the access time slot selected in the first determination step; a first processing step being active by the first determining step to format user information data to be transmitted; a second transmission step for receiving the formatted signal of user information from the first step of processing, spreading and outputting the signal with the channelization code corresponding to the preamble signature; a selection step for selecting either the data produced at the second transmission step, or the preamble produced at the first transmission step according to the acquisition indication signal 35 transmitted from the 56 base station (200 ); a second processing step for transforming the signal selected at the selection step into a high frequency signal and for transmitting it to the base station (200) via a wireless channel, and transformation of an acquisition indication signal in a high frequency signal transmitted from the base station (200) in a baseband signal; a reception step for receiving the signal of acquisition band signal of base from the second processing step and verification of whether the transmitted preamble signature is acquired or not; and15 a second determination step to validate and invalidate the first determination step according to the result verified at the reception step, and output of a signal to switch the selection step. 18. The method as claimed in claim 17, characterized in that the first determination step comprises the following steps: reception and storage of information concerning the set of preamble signatures classified by a traffic characteristic transmitted from the base station ( 200) via a common direct link channel; ranking the data produced by considering traffic characteristics and demand conditions from the upper layer, and random selection of a preamble signature from the available preamble signatures corresponding to the traffic characteristic; random or deterministic selection of an access time slot when the preamble is transmitted; and determining the power of a preamble of 57 transmission by considering a signal level   interference from the base station (200), loss of direct link path, and the power level of the preamble previously transmitted if applicable.   19. The method of claim 17, characterized in that the first step of transmission transmits the   preamble with the preamble signature and the power level at the transmission time slot in the first determination step and by modulating a common spreading code10 by the preamble signature.   20. The method of claim 19, characterized in that the first step of transmission produces a   complex band spread signal whose actual value is the same as the imaginary value using the selected preamble signature and the common spread code.   21. Method according to claim 17, characterized in that the reception step receives the acquisition indication signal using a sequence 20 corresponding to the preamble signature transmitted and a spreading code assigned to the common direct link channel for transmission of acquisition indication. 22. The method of claim 17, characterized in that the second determination step validates the first determination step and outputs a signal to connect the output of the first transmission step to the selection step, if the indication signal positive acquisition or acquisition in function is received; otherwise, the second determination step 30 invalidates the first determination step, and links the output of the second transmission step to the selection step. 23. The method of claim 16, characterized in that the base station (200) further performs the following steps: a first step of receiving a high frequency signal transmitted from the terminal, and transmission of a signal high frequency at the terminal; a second step of receiving the preamble transmitted from the terminal via the common reverse link channel from the first step, and carrying out the acquisition of the preamble with all the preamble signatures available; a third step of verification of the acquisition, determination and output of the acquired preamble signatures; a fourth step of producing multiple acquisition indication signals corresponding to the acquired preamble signatures entered from the third step, and output of the signal to the terminal (100) via the first step; and a fifth step of receiving multiple path time delay information obtained from the second step, producing a reverse spreading code using the information regarding the acquired preamble signature received from the   third step, reception of the data transmitted from the terminal via the common reverse link channel coming from the first step, and reception of the data processed by channel modulation and decoding.   24. The method as claimed in claim 23, characterized in that the second step comprises the following steps: reception of the preamble transmitted from the terminal (100) via the common reverse link channel from the first step, and completion of the acquisition of a preamble with all the preamble signatures available; 35 instruction in the fifth step to identify a time delay characteristic 59 corresponding to the   preamble signature acquired, and instruction in the fifth step to be ready to receive data to be transmitted at a predefined time if necessary; and5 information at the third stage of which preamble signatures are acquired.   25. The method as claimed in claim 23, characterized in that the third step comprises the following steps: informing a spreading code corresponding to the preamble signature entered from the second step to the fifth step, and instruction in the fifth step to be ready to receive data to be transmitted at a predefined time if necessary; and producing acquisition indication signals corresponding only to the preambles acquired and outputting the signals to the fourth step. 26. The method of claim 23, characterized in that the fourth step transmits any signals so that the acquisition indication signals are orthogonal or antipodal to each other. 27. The method as claimed in claim 23, characterized in that the fourth step produces and transmits the acquisition indication signal as a combination of a combined or selected format comprising: an on-off signal format for dividing the times available in number of available signatures and to assign each divided time to each available preamble signature, to transmit acquisition indication signals only on the divided times allocated to acquired preamble signatures, and to transmit no indication signal acquisition over the divided time allocated to the 35 unearned preamble signatures; an antipodal signal format for dividing the available times into the number of available signatures and for assigning each divided time to each available preamble signature, and for transmitting positive acquisition indication signals5 for acquired preamble signatures and d signals negative acquisition indication for unacquired preamble signatures on all divided times allocated to available preamble signatures; 10 an on-off signal format for assigning an orthogonal code to a preamble signature and for positioning it as symbol to be transmitted, and to transmit only an orthogonal code corresponding to the acquired preamble signature; and15 an antipodal signal format for assigning an orthogonal code to the preamble signature and for positioning it as a symbol, for transmitting positive acquisition indication signals for acquired preamble signatures and indication signals negative acquisition for unacquired preamble signatures, all orthogonal codes   being attributed to the available preamble signatures.   28. The method of claim 27, characterized in that the fourth step is carried out by one of the methods comprising: a penetration method applied to a common channel with an anterior direct link; a method using a code orthogonal to the other common direct link channel; and   a method using a code that is not orthogonal to the other common direct link channel.   29. Method according to claim 16, characterized in that the base station (200) classifies data characteristics to be transmitted via a common reverse link channel into a direct and packet access 61 for transmitting data short, a channel reservation request to transmit intermediate data, and a channel request requesting dedicated channel allocation to transmit a large continuous stream of data, allocates preamble signatures according to specifications   classified data to be transmitted, and transmits the information concerning the preamble signatures allocated via a common direct link channel for all the terminals to identify them.   30. The method as claimed in claim 29, characterized in that if data having a multiple frame length is served by direct access and by 15 packets, the base station (200) classifies, in a secondary manner, the preamble signatures allocated to direct and packet access depending on the length of the data. 31. Method according to claim 29, characterized in that if data are served by the channel reservation request, the method is carried out by the following steps: random selection by the terminal (100) of one of the preamble signatures allocated for channel reservation and transmission of a preamble; realization by the base station (200) of a preamble code acquisition transmitted from the terminals and information to all the terminals (100) of the preamble signature acquired via a common direct link channel; if the terminal (100) receives an acquisition indication signal for a successful preamble acquisition, random selection by the terminal (100) of one of the preamble signatures allocated for a channel reservation, determination of a slot access time, 62 and retransmission of a preamble; if the terminal (100) receives an acquisition indication signal for a failed preamble acquisition, transmission by the terminal (100) of the data for a reservation request and attempt of a channel reservation after transmission of data for a channel reservation request; informing the corresponding terminals (100) by the base station (200) of a channel reservation, a reserved time, a spreading code, and a maximum admissible transmission speed, if successful reception of the data transmitted for a channel reservation request from a terminal (100); transmission of data by the corresponding terminal (100) using the spreading code over the time reserved in the range of maximum admissible transmission speeds, and production of a power control by means of a power control command via a dedicated or shared direct channel; and transmission by the terminal of information indicating the completion of a data transmission with data during the transmission of a final frame, and cancellation of the channel reservation. 32. Method according to claim 31, characterized in that the terminal (100) transmits data to modify the channel reservation condition with the current transmission data, in parallel, in the same way as direct and packet access and the channel reservation request during the reservation, or multiplexes and transmits the data with the data previously reserved.