KR20090102594A - Method and apparatus for transmission and reception of control information in mobile telecommunication system supporting hsdpa - Google Patents

Abstract

PURPOSE: A control information transmitting and receiving method and an apparatus thereof in a mobile communication system are provided to improve receiving reliability by controlling transmission power of serving cell switching recognition information. CONSTITUTION: A method transmitting control information in a mobile communication system is as follows. The radio network controller receives the measurement report about the downlink channel state from the terminal(402). According to the measurement report content, it determines the serving cell about the terminal is converted to the purpose cell from the source cell. The data in which it sends to the terminal are transmitted to the source cell and purpose cell(418). A purpose cell transmits the power control information about the upward link signal and serving cell change over pointer with the terminal.

Description

METHOD AND APPARATUS FOR TRANSMISSION AND RECEPTION OF CONTROL INFORMATION IN MOBILE TELECOMMUNICATION SYSTEM SUPPORTING HSDPA}

The present invention relates to a mobile communication system, and more particularly, to a method and apparatus for transmitting and receiving control information for serving cell change in a situation of using a high speed downlink packet data service.

Third generation mobile communication system based on European system of Global Communications for Mobile Communications (GSM) and General Packet Radio Services (GPRS) and using Wideband Code Division Multiple Access (CDMA) The Universal Mobile Telecommunication Service (UMTS) system provides a consistent service that enables mobile phone or computer users to transmit packet-based text, digitized voice or video and multimedia data at high speeds, anywhere in the world.

In particular, in the UMTS system, a high speed downlink packet access (High Speed) is used to further improve the performance of packet transmission in the forward, that is, downlink (DL) communication from a base station (Node B) to a user equipment (UE). Downlink Pack Access (HSDPA) method is supported. HSDPA supports technologies such as Adaptive Modulation and Coding (AMC) and Hybrid Automatic Retransmission Request (HARQ) to support more stable and high speed data transmission. In the modulation scheme, one of QPSK, 16QAM, and 64QAM is adaptively selected according to channel conditions. The HARQ may be implemented in a fast retransmission and soft combining scheme. That is, retransmission is performed between the UE and the Node B with respect to the errored data, and soft combining is performed on the retransmitted data to improve overall communication efficiency. As control information exchanged between UE and Node B, channel quality information and modulation scheme information necessary for adaptively determining an OVSF (Orthogonal Variable Spreading Factor) code, a transport block size, and a modulation scheme to be used by an arbitrary UE according to channel conditions , Channel number information and ACK / NACK information necessary for supporting HARQ.

1 is a diagram illustrating a general structure of an asynchronous mobile communication system supporting the HSDPA method.

Referring to FIG. 1, the asynchronous mobile communication system is referred to as a core network (hereinafter referred to as "CN") 100 and a plurality of radio network subsystems (hereinafter referred to as "RNS"). 110 and 120 and the UE 130.

The RNS 110 is composed of a Radio Network Controller (hereinafter referred to as "RNC") 111 and a plurality of base stations 115 and 113. The RNS 120 also includes an RNC 112 and a plurality of Node Bs 114 and 116. The base station is composed of a plurality of cells. On the other hand, it should be noted that the term "base station" is used interchangeably with the term "Node B" for convenience of description below. The interface between the RNC and the Node B is called an Iub interface, and the interface between the RNCs is called an Iur interface. The RNCs 111 and 112 manage information of respective UEs and are responsible for data transmission with the core network 100. The interface between the RNC and the core network is called an lu interface. The cell connected to the UE and performing communication is called a serving cell. For example, in FIG. 1, the cell 117 communicating with the UE 130 becomes a serving cell. However, when the UE moves, the serving cell should be switched accordingly.

Hereinafter, a serving cell change procedure in the conventional HSDPA scheme will be described with reference to FIG. 2.

The UE 201 performs data transmission / reception with the source cell 202 (206). The source cell refers to a cell that performs data transmission / reception with the UE before serving cell switching is completed, and the target cell refers to a cell performing data transmission / reception with the UE after serving cell switching is completed. The UE periodically measures the downlink channel state from the received signal strength of pilots transmitted from neighbor cells and reports it to the RNC 204 periodically, or when the received pilot signal strengths of the target cell and the source cell exceed a predetermined threshold. report. The measurement is communicated to the RNC 204 via the source cell in the form of a radio resource control message (RRC) (208). From the reported RRC message, the RNC 204 determines whether to keep the current source cell 202 as a serving cell for the UE or to perform serving cell switching to the destination cell 203. If the downlink channel state from the destination cell 203 is better than the threshold channel state from the source cell 202 by a predetermined threshold or more, then the RNC 204 selects the destination cell 203 from the source cell 202. Serving cell switching is performed. The RNC 204 instructs the target cell 203 to prepare a radio link reconfiguration (210), and the target cell 203 prepares the radio link reconfiguration to the RNC 204 (radio link reconfiguration ready). 212, the RNC 204 again instructs the destination cell 203 to perform a radio link reconfiguration commit to cause the destination cell 203 to perform a series of serving cell transitions. Do it. The RNC 204 then directs the UE to serving cell switching by sending a radio bearer reconfiguration message to the UE 201 (216). The radio bearer reset message is sent from the RNC 204 to the UE 201 via the source cell 202. The UE 201 recognizes that a serving cell switch is made from the source cell 202 to the destination cell 203 by receiving the radio bearer reset message, and the radio bearer completes to the RNC 204. The 220 notifies that serving cell switching has been performed by sending a message. The radio bearer complete message is delivered from the UE 201 to the RNC 204 via the destination cell 203. Thereafter, the UE 201 performs data transmission / reception using the destination cell 203 as a new serving cell (224).

When the serving cell is switched, communication must be seamless and transmission delay must be minimized. This is an important factor that determines service quality, especially for real-time services such as voice calls. However, the conventional serving cell switching procedure described above with reference to FIG. 2 has the following problems.

The RNC sends a message indicating the serving cell switching to the UE via the source cell in the form of an RRC message. The RNC determines that the destination cell is better than the downlink channel state of the source cell and determines serving cell switching. The RNC transmits a message indicating the serving cell switching via the source cell having a relatively poor channel state. The probability of successful reception is reduced, resulting in transmission delay or packet loss.

In addition, the UE sends a message to the RNC that feedback that the UE has successfully received the serving cell switch indication message, thereby causing additional transmission delay.

An object of the present invention is to provide a method for transmitting / receiving control information enabling fast serving cell switching in a mobile communication system to which an HSDPA scheme is applied.

According to an embodiment of the present invention, in a method for transmitting control information in a mobile communication system, a wireless network controller receives a measurement report on a downlink channel state from a terminal, and according to the measurement report, Determining to switch a serving cell from a source cell to a target cell, instructing the wireless network controller to perform serving cell switching from the source cell and the serving cell, and transmitting data to the terminal to transmit the data to the terminal; Transmitting to a target cell; transmitting, by the target cell, power control information about a serving cell switching indicator and an uplink signal to the terminal; and receiving, by the target cell, a response signal for serving cell switching from the terminal. And performing data communication with the terminal.

In addition, according to an embodiment of the present invention, in a method for receiving control information in a mobile communication system, a process of a terminal transmitting a measurement report on a downlink channel state to a source cell, and the terminal is a serving cell switching indicator from a target cell And receiving power control information for the uplink, transmitting a response message to which the power control information is applied to the target cell, and performing a data communication by the terminal with the target cell.

In addition, according to an embodiment of the present invention, in the apparatus for transmitting control information in a mobile communication system, a serving cell switching controller for determining whether to switch the serving cell according to the uplink channel state information received from the terminal, the serving cell switching Control information generation unit for generating the control information and serving cell switching indicator and uplink power control information for serving cell switching according to the controller's decision, the generated control information, serving cell switching indicator and uplink power control information And a transmitter for encoding, multiplexing, and transmitting the signals.

Further, according to an embodiment of the present invention, in the apparatus for receiving control information in a mobile communication system, a control information obtainer for obtaining serving cell switching control information from the received signal, and the validity of the control information obtained by the control information obtainer And a serving cell switching controller configured to set uplink transmission power according to the control information if the control information is valid.

When the effect obtained by the typical thing of the invention disclosed below is demonstrated briefly, it is as follows.

The present invention, when the UE receives the serving cell switching indication information from the base station in the procedure of performing the serving cell switching in a mobile communication system supporting the HSDPA service, and feeds back corresponding serving cell switching recognition information to the base station, the base station By adjusting the transmission power of the serving cell switching recognition information by reflecting the uplink channel state as described above, it is possible to improve reception reliability and perform fast serving cell switching.

1 is a diagram illustrating a general structure of an asynchronous mobile communication system supporting the HSDPA method.

2 is a diagram illustrating a serving cell switching procedure in the conventional HSDPA scheme.

3 illustrates an enhanced HSDPA serving cell switching procedure.

4 is a diagram illustrating an operation procedure of a network for switching a serving cell according to the present invention.

5 is a diagram illustrating an operation procedure of a terminal for switching a serving cell according to the present invention.

6 is a diagram illustrating the structure of an HSDPA serving cell switch indication channel according to a first embodiment of the present invention;

7 is a diagram illustrating an HSDPA serving cell switching indication channel transmitter of a base station according to a first embodiment of the present invention;

8 illustrates an apparatus for receiving HSDPA serving cell switching indication channel of a UE according to an embodiment of the present invention.

9 is a diagram illustrating an HSDPA serving cell switching indication channel transmitter of a base station according to a second embodiment of the present invention;

10 is a diagram illustrating an HSDPA serving cell switch indication channel receiver of a UE according to a second embodiment of the present invention;

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The present invention to be described below specifically describes a method and apparatus for transmitting reliable control information for serving cell change in a UMTS mobile communication system supporting a high speed downlink packet access (HSDPA) service. something to do. However, of course, the present invention can be applied to other similar communication systems.

Hereinafter, an enhanced HSDPA serving cell switching procedure will be described with reference to FIG. 3.

The UE 301 performs data transmission / reception with the source cell 302 (305). The UE 301 periodically measures the downlink channel state from the received signal strength of pilots transmitted from neighbor cells and reports it to the RNC 304 periodically, or receives the received pilot signal strengths of the target cell 303 and the source cell 302. Report when is greater than a predetermined threshold. The measurement report is communicated to the RNC 304 via the source cell 302 in the form of a radio resource control message (RRC) (306).

The UE 301 detects whether a serving cell switch indicator is received from the destination cell 303 after transmitting the measurement report RRC message. The RNC 304 determines whether to keep the current source cell 302 as a serving cell for the UE 301 or perform serving cell switching to the destination cell 303 from the RRC message reported from the UE. . If the downlink channel state from the destination cell 303 is better than the threshold channel state from the source cell 302 by a predetermined threshold or more, then the RNC 304 may remove the destination cell 303 from the source cell 302. Decide to perform serving cell switching.

Accordingly, the RNC 304 instructs the destination cell 303 to perform serving cell switching by instructing the destination cell 303 to perform radio link reconfiguration commit (310), and also serves the source cell 302. Instruct 312 to prepare for cell switching. The RNC 304 transmits the data to be transmitted to the UE 301 to the destination cell 303 and the source cell 302, respectively (314 and 316).

The source cell 302 continues to transmit data to the UE 301 until the serving cell switch is complete. The destination cell 303 transmits a serving cell change indicator to the UE 301 (318, 320), and when receiving a serving cell change acknowledgment signal from the UE 301. The serving cell switch indicator is repeatedly transmitted to the UE. The serving cell switching indicator may transmit a modified HS-SCCH (downlink control channel), which is a downlink control channel for supporting the conventional HSDPA, or define and transmit a separate independent serving cell switching control channel. have.

When the UE 301 successfully receives the serving cell switch indicator 322, the UE 301 sends a serving cell switch acknowledgment signal to the destination cell 303 to notify that the serving cell switch indicator has been successfully received. (324). In this case, the UE 301 should appropriately set the transmission power for the serving cell switch acknowledgment signal so that the target cell 303 can successfully receive the serving cell switch acknowledgment signal. The serving cell switch acknowledgment signal may be notified by using a specific codeword of CQI (Channel Quality Information) control information for supporting conventional HSDPA, or by changing an uplink scrambling code or inserting into uplink data.

When the destination cell 303 successfully receives the serving cell switch acknowledgment signal (326), it starts to transmit data to the UE 301 (328). The destination cell 303 notifies the RNC 304 that serving cell switching is complete (330).

 Next, a method of properly setting the transmission power of the serving cell switch acknowledgment signal of the UE will be described.

In a frequency division duplex (FDD) system, since uplink and downlink transmission bands are distinguished, there is a feature that the correlation between uplink and downlink channel states is not high. That is, even if the downlink channel state from the target cell is good, the uplink channel state to the target cell is also not good. Accordingly, in order for the UE to successfully transmit the serving cell switch acknowledgment signal to the target cell, the UE receives power control information from the target cell, and transmits the transmission power of the serving cell switch acknowledgment signal according to the received power control information. You need to set it. That is, the transmission power of the serving cell switch acknowledgment signal follows the power control information of the target cell regardless of the power control information of the source cell.

Through the improved serving cell switching procedure, the serving cell switching message, which has been pointed out as a problem of the serving cell switching procedure, can be solved. In addition, an additional transmission delay can be reduced by allowing the serving cell switch acknowledgment signal to be detected directly in the target cell.

Hereinafter, an operation procedure of a network for switching serving cells will be described with reference to FIG. 4.

The serving cell switching procedure starts at step 402 with the RNC receiving a measurement report on the downlink channel condition from the UE. In step 403, the RNC detects the downlink channel state of the target cell through the measurement report received from the UE. That is, when the downlink channel state of the target cell is better than the predetermined downlink channel state of the source cell, the RNC transmits serving cell switching related control information to the source cell and the target cell in step 404. If the downlink channel state of the target cell is worse than the downlink channel state of the source cell in step 403, the RNC branches to step 402 and waits for the next channel state measurement report to be received from the UE.

In step 406, the RNC transmits data to be transmitted to the UE to the target cell and the source cell, respectively, so that the source cell continues to transmit the data to the UE until the serving cell switch detection signal is detected, and the target cell is serving cell switch recognition. Immediately after the signal is successfully detected, the data transmission is started to the UE.

In step 408, the target cell measures the uplink channel state from the pilot signal received from the UE, sets the power control information of the UE according to the measured uplink channel state in step 410, and switches the serving cell to the UE in step 412. The indicator and the power control information are transmitted together. The serving cell switching indicator and the power control information are transmitted by modifying the HS-SCCH, which is a downlink control channel for supporting the conventional HSDPA, or by defining a separate independent serving cell switching control channel.

In step 414, the target cell attempts to detect a serving cell switch acknowledgment signal from the UE. The UE uses a specific codeword of CQI control information for supporting the conventional HSDPA as the serving cell switch acknowledgment signal or changes the uplink scrambling code. If the target cell succeeds in detecting the serving cell switch acknowledgment signal in step 416, it starts data transmission to the UE in step 418. If the detection of the serving cell switch acknowledgment signal fails in step 416, the target cell branches to step 412 to retransmit the serving cell switch indicator to the UE.

In step 420, the target cell terminates the serving cell switch procedure by transmitting a serving cell switch complete message to the RNC.

Hereinafter, an operation procedure of the UE for switching the serving cell will be described with reference to FIG. 5.

In step 502, the UE measures downlink channel states of the source cell and neighbor cells. In step 504, it is determined whether the target cell is better than the downlink channel state of the source cell or whether a predefined measurement report time point arrives. If it is determined that the target cell is better than the downlink channel state of the source cell or a predefined measurement report time point arrives, the UE reports the measured channel state to the RNC in step 506. If it is determined in step 504 that the target cell is not better than the downlink channel state of the source cell or the predefined reporting time has not yet arrived, the UE branches to step 502 and performs measurement on the downlink channel state again. do.

In step 508, the UE checks whether the serving cell switch indicator and power control information are received from the target cell, and simultaneously receives data from the source cell. The destination cell transmits the serving cell switching indicator and power control information by modifying the HS-SCCH, which is a downlink control channel for supporting the conventional HSDPA, or by defining a separate independent serving cell switching control channel. Can be. If the UE succeeds in detecting the serving cell switch indicator and power control information in step 510, the UE sets transmission power of the serving cell switch acknowledgment signal using the power control information received from the target cell in step 512. If the serving cell switch indicator and power control information detection fails in step 510, the UE branches to step 508 to perform detection of the serving cell switch indicator and power control information from the target cell again.

In step 514, the UE transmits a serving cell switch acknowledgment signal to the target cell. The UE uses a specific codeword of CQI control information for supporting the conventional HSDPA as the serving cell switch acknowledgment signal, changes an uplink scrambling code, or inserts a serving cell switch acknowledgment signal into the uplink data. Can be used. The UE ends the serving cell switching procedure by receiving data from the destination cell in step 516.

Hereinafter, an embodiment of the present invention will be described with reference to a specific embodiment of the method for transmitting the serving cell switching indicator and power control information by the target cell.

<First Embodiment>

The first embodiment of the present invention proposes a method of transmitting a serving cell switching indicator and power control information by changing the HS-SCCH, which is a downlink control channel for supporting a conventional HSDPA.

Control information included in the conventional HS-SCCH includes 7 bits of information about OVSF codes to be used for HSDPA data transmission, 1 bit of modulation scheme to be applied to HSDPA data, 6 bits of HSDPA data, 7 bits of HARQ related information, and UE- There are 16 bits of ID. The HARQ related information may include three bits of HARQ process number of data to be transmitted through HSDPA, three bits of redundancy version (hereinafter referred to as "RV") of data to be transmitted through HSDPA, and data to be transmitted through HSDPA. A new data indicator indicating whether or not is new data consists of 1 bit.

The HS-SCCH configured with the above control information may be used for instructing discontinuous reception (DRX) and discontinuous transmission (DTX) operation to increase battery efficiency of the UE. In this case, the HS-SCCH Some of the control information uses a predetermined fixed value, and the other part of the control information is used for instructing the DRX and DTX operations. The HS-SCCH defined for this purpose is called an HS-SCCH order channel. Since the HS-SCCH order channel is not intended to provide control information for HSDPA data, the HS-SCCH order channel operates independently without involving the HSDPA data channel.

FIG. 6 shows an HSDPA serving cell switching indicator in which the HS-SCCH order channel is modified and a control channel for transmitting power control information (hereinafter referred to as an HSDPA serving cell switching indication channel for convenience). The HSDPA serving cell switch indication channel operates independently without involving the HSDPA data channel.

The HSDPA serving cell switch indication channel is composed of 37 bits in total like the conventional HS-SCCH and HS-SCCH order channels. The first 8 bits 602 are bits corresponding to 7 bits of information on the OVSF codes of the conventional HS-SCCH and 1 bit of a modulation scheme to be applied to the HSDPA data, and use a fixed value of the first predetermined pattern. The first predetermined pattern is '11100000'. The six bits 604 after the eight bits 602 are bits corresponding to six bits of the HSDPA data size of the conventional HS-SCCH, and use a fixed value of the second predetermined pattern. The second predetermined pattern is '111101'. The 3 bits 606 after the 6 bits 604 are bits corresponding to 3 bits of the HARQ process number of the conventional HS-SCCH, and use a fixed value of a third predetermined pattern. The predefined third pattern is '000'. The 3 bits 608 after the 3 bits 606 are bits corresponding to the redundant versions of the data to be transmitted through the HSDPA of the conventional HS-SCCH, and indicate DRX and DTX operation or HSDPA serving cell switching indicator and power. It is used to indicate control information.

The analysis method of the 3 bits 608 is shown in Table 1.

b1, b2 b3 Translate xx 0 Performing the DTX and DRX Operation of the conventional HS-SCCH order 00 One HSDPA Serving Cell Switching Instruction and Power Control Information # 1 01 One HSDPA Serving Cell Switching Instruction and Power Control Information # 2 10 One HSDPA Serving Cell Switching Instruction and Power Control Information # 3 11 One HSDPA Serving Cell Switching Instruction and Power Control Information # 4

According to Table 1, DTX and DRX operations according to the conventional HS-SCCH order defined according to the values of b1 and b2 when b3 = 0 according to the value of b3 among the three bits 608 b1, b2 and b3. When b3 = 1, HSDPA serving cell switching is indicated, and power control information is additionally provided according to the values of b1 and b2.

That is, when <b1, b2, b3> = <0,0,1>, the HSDPA serving cell switching is instructed, the power control information # 1 is indicated, and <b1, b2, b3> = <0,1,1. >, Instructing HSDPA serving cell switching, indicating power control information # 2, and if <b1, b2, b3> = <1,0,1>, indicating HSDPA serving cell switching, and power control information # 3. If <b1, b2, b3> = <1, 1, 1>, the HSDPA serving cell switching is indicated, and the power control information # 4 is indicated.

The power control information # 1, # 2, # 3, # 4 are different values previously promised, and the transmission power of serving cell switching recognition information transmitted by the UE depends on the uplink channel state from the UE to the target cell. This indicates how much boosting should be boosted relative to the reference transmission power of the UE. For example, when the power control information # 1 = 0 dB, the power control information # 2 = 1 dB, the power control information # 3 = 3 dB, and the power control information # 4 = 6 dB are previously defined, the power control information # 1 is defined by the UE. Set the transmission power of the serving cell switching recognition information to the same value as the reference transmission power of the UE, and the power control information # 2 sets the transmission power of the serving cell switching recognition information of the UE to be 1 dB higher than the reference transmission power of the UE. The power control information # 3 sets the transmission power of the serving cell switching recognition information of the UE to be 3 dB higher than the reference transmission power of the UE, and the power control information # 4 sets the transmission power of the serving cell switching recognition information of the UE as the reference of the UE. Set to 6dB higher than the transmission power.

In FIG. 6, one bit of reference numeral 610 is a value corresponding to one bit of a new data identifier of the conventional HS-SCCH and is left unused in the HSDPA serving cell switching indication channel. The UE-ID specific CRC of the reference numeral 612 is generated by performing an XOR operation on the CRC 16 bits generated by inputting the above-described control information 602, 604, 606, 608, 610 with the UE-ID 16 bits.

7 shows an HSDPA serving cell switch indication channel transmitter of a base station according to a first embodiment of the present invention. For convenience of description, channels other than the HSDPA serving cell switch indication channel are omitted.

The HSDPA Serving Cell Switching Indication Channel is transmitted using an OVSF code having a spreading factor of 128, such as HS-SCCH, and the first predetermined pattern '11100000' is the first slot of slots constituting the HSDPA Serving Cell Switching Indication Channel. Is transmitted in 40 bits, and control information other than the first predetermined pattern is transmitted in 80 bits through the second and third slots of the slots constituting the HSDPA serving cell switching indication channel. As such, by dividing the HSDPA serving cell switching indication channel into two parts and channel coding separately, the UE identifies whether the received channel is the HSDPA serving cell switching indication channel even if the UE receives only the first slot in which the first predetermined pattern is transmitted. I can do it.

The serving cell switching controller 702 sets whether to indicate serving cell switching according to a serving cell switching command provided from the RNC, and uses the uplink channel state information 703 measured from the pilot signal received from the UE to determine the HSDPA serving cell. Sets the power control information of the switch indication channel.

The control information generation unit # 1 704 generates the pre-scheduled first pattern information when the serving cell switching controller 702 is commanded to generate the serving cell switching instruction channel, and the encoder # 1 706 generates the generated first pattern information. The first pattern information is encoded by a convolutional code having a code rate of 1/3. The rate matcher 708 rate-matches the encoded first pattern information to 40 bits corresponding to one slot. When the control information generation unit # 2 714 receives a command for generating a serving cell switching indication channel from the serving cell switching controller 702, the control information generation unit # 2 714 receives the predetermined second pattern information 716 and the predetermined third pattern information ( 718, a serving cell switch indicator and power control information 720, a reserved bit 722, and a UE-DI specific CRC 724 are generated. The power control information 720 is generated according to Table 1 as the transmission power of the serving cell switching recognition signal of the UE determined according to the uplink channel state information measured from the pilot signal received from the UE. The UE-DI specific CRC 724 stores a 16-bit CRC generated by inputting control information generated by the control information generator # 1 704 and the control information generator # 2 714 as the UE-ID 16 bits. Generated by XOR operation. The encoder # 2 726 encodes the control information generated by the control information generator # 2 714 into a convolutional code having a code rate of 1/3, and the rate matcher 728 stores the encoded control information. Rate matching is performed using the 80 bits corresponding to the slot. The multiplexer 710 multiplexes the signals input from the rate matching units 708 and 728, and the transmitter 712 transmits the multiplexed signal through signal processing such as OVSF code spreading and scrambling.

8 shows an HSDPA serving cell switch indication channel receiver of a UE according to a first embodiment of the present invention. For convenience of description, channels other than the HSDPA serving cell switch indication channel are omitted.

The receiver 802 performs signal processing such as descrambling and despreading the received signal, and the demultiplexer 804 controls control information of the first slot and control of the second and third slots of the HSDPA serving cell switching indication channel. Separate information. The control information of the first slot is reverse rate matched by the inverse rate matcher 806, and decoded by a convolutional code having a code rate of 1/3 in decoder # 1 808, and then obtained by the control information obtainer # 1 810. Is entered. The control information obtainer # 1 810 obtains a first predetermined pattern from the control information of the decoded first slot. The control information of the second and third slots separated from the demultiplexer 804 is reverse rate matched by the reverse rate matcher 814 and a convolutional code having a code rate of 1/3 in decoder # 2 816. After decoding, it is input to the control information obtainer # 2 818. The control information obtainer # 2 818 examines the control information decoded by the decoder # 2 816 to check that there is no error through a CRC check, and if there is no error, the second pattern previously promised from the decoded control information. 820, the third pattern 822, the serving cell switch control information 824, the Reserved 826, and the UE-ID specific CRC 828 are acquired and applied to the serving cell switch controller 812. The serving cell switch controller 812 is a HSDPA serving of a predetermined first pattern, second pattern, and third pattern of control information received from the control information obtainer # 1 810 and the control information obtainer # 2 818. After confirming that it matches the pattern defined for the cell switching indication channel use, if it matches, it is determined that the obtained serving cell switching indicator and the power control information are valid and analyzed according to the method of <Table 1>, and then serving cell switching recognition signal. It is applied to set the transmission power of.

In another implementation method of the first embodiment of the present invention, the HSDPA serving cell switching indicator and power control information may be defined as 1 bit of reference number 610 instead of 3 bits of reference number 608 in FIG. 6. In this case, for example, when 1 bit of reference numeral 610 is '0', it indicates to switch the HSDPA serving cell and apply the transmission power of the serving cell switching recognition information of the UE to the reference transmission power of the UE by the power control information # 1. If 1 bit of reference numeral 610 is '1', it may indicate HSDPA serving cell switching and apply transmission power of serving cell switching recognition information of UE to power transmission information # 2 to reference transmission power of UE.

Second Embodiment

The second embodiment of the present invention modifies the channel structure of an E-RGCH (E-DCH Relative Grant Channel), which is a downlink control channel of a conventional High Speed Uplink Packet Access (HSUPA), so that the target cell is serving cell switching indicator and power control information. Suggest a way to send it.

In the conventional E-RGCH, when the base station transmits 3-state control information of up / maintain / decrease as a scheduling command to the UE, the control information for channel multiplexing with the E-RGCH transmitted to another UE. Multiply by the orthogonal sequence of length 40 and send. The signal is repeatedly transmitted over several slots to improve reception reliability of the UE.

According to a second embodiment of the present invention, the control information of the HSDPA serving cell switching indication channel is defined as a 2-state, and the control information is transmitted in an orthogonal sequence by multiplexing in a similar manner to the E-RGCH. The physical channel mapping and interpretation method of the 2-state control information follows Table 2.

Physical Channel Mapping of HSDPA Serving Cell Switching Control Information Translate -One HSDPA Serving Cell Switching Instruction and Power Control Information # 1 One HSDPA Serving Cell Switching Instruction and Power Control Information # 2

The power control information # 1 and # 2 of Table 2 are previously promised different values, and according to the uplink channel state from the UE to the target cell, the transmit power of the serving cell switch recognition information transmitted by the UE is determined. This indicates how much boosting is compared to the reference transmission power of.

For example, when the power control information # 1 = 0dB and the power control information # 2 = 3dB are previously defined, if the physical channel mapping of the HSDPA serving cell switching control information is '-1', the HSDPA serving cell switching is instructed to the UE. The transmission power of the serving cell switching recognition information of the UE is set to be the same as the reference transmission power of the UE.If the physical channel mapping of the HSDPA serving cell switching control information is '1', the HSDPA serving cell switching is indicated and the serving cell switching recognition of the UE is performed. The transmission power of the information is set to be 3 dB higher than the reference transmission power of the UE.

9 shows an HSDPA serving cell switching indication channel transmitter of a base station according to a second embodiment of the present invention. For convenience of description, channels other than the HSDPA serving cell switch indication channel are omitted.

The base station may use orthogonal sequences having a total length of K and transmit up to K HSDPA serving cell switching control information for K UEs through one common code channel. A representative example of the orthogonal sequence is a Hadamard sequence. In the second embodiment of the present invention, the case where K = 40 will be described as an example. The HSDPA serving cell switch indication channel is transmitted using an OVSF code having a spreading factor of 128, such as an E-RGCH.

Referring to FIG. 9, the serving cell switching controller 902 sets whether to indicate serving cell switching according to a serving cell switching command provided from the RNC, and measures uplink channel state information 903 measured from a pilot signal received from the UE. ) To set the power control information of the HSDPA serving cell switch indication channel and apply it to the serving cell switch control information mapper 904. The serving cell switch control information mapper 904 generates the mapped control information into physical channel bits according to Table 2 above.

That is, the serving cell switching control information mapper 904 instructs the UE to switch the HSDPA serving cell and sets the transmission power of the serving cell switching recognition information of the UE by increasing the power control information # 1 previously promised relative to the reference transmission power of the UE. To do so, the physical channel mapping of the HSDPA serving cell switching control information is generated as '-1'. In order to instruct the UE to switch the HSDPA serving cell and to set the transmission power of the serving cell switching recognition information of the UE to be set by increasing the power control information # 2 in advance to the reference transmission power of the UE, the physical channel of the HSDPA serving cell switching control information Create a mapping of '1'.

The HSDPA serving cell switching control signal generated as described above is converted into transmit power by an appropriate gain 908 for each UE in the multiplier 906 for reliable transmission. The orthogonal sequence generator 912 receives an orthogonal sequence from a total of K orthogonal sequences from the serving cell switching controller 902, generates an orthogonal sequence, and inputs the orthogonal sequence to the spreader 910. The orthogonal sequence used by the HSDPA serving cell switching indication channel is a value that is commonly recognized between the UE and the base station by using a predetermined value or by higher signaling. The TTI length of the HSDPA serving cell switching indication channel is represented by N slots and uses a predefined value.

The transmit power-adjusted HSDPA serving cell switching control signal is spread in an orthogonal sequence allocated for each UE in the spreader 910 to distinguish each UE, and then the repeater 914 transmits a TTI (TTI) of the HSDPA serving cell switching indication channel. time interval) is generated repeatedly according to the length. The transmitter 916 spreads the repetitive signal chip level using a common channel code allocated for the HSDPA serving cell switching indication channel, and then scrambles the transmitted signal to the UE. The common channel code used by the HSDPA serving cell switching indication channel is a value that is commonly recognized between the UE and the base station by using a predetermined value or by higher signaling.

10 shows an HSDPA serving cell switch indication channel receiver of a UE according to a second embodiment of the present invention. For convenience of description, channels other than the HSDPA serving cell switch indication channel are omitted.

The receiver 1002 extracts the HSDPA serving cell switching indication channel by performing signal processing such as descrambling and despreading the received signal. The accumulator 1004 accumulates the extracted HSDPA serving cell switching indication channel signal by the number of times repeated by the base station repeater 914 of FIG. 9.

The accumulated signal has a length for one slot period, and the correlator 1006 takes a correlation value in an orthogonal sequence assigned to the UE and applies it to the serving cell switch control information extractor 1008. The serving cell switch controller 1012 controls orthogonal sequence generation by applying orthogonal sequence information for the HSDPA serving cell switch indication channel allocated thereto to the orthogonal sequence generator 1014. The serving cell switch control information extractor 1008 compares the correlation value received from the correlator 1006 with a preset threshold and outputs an HSDPA serving cell switch control signal, which is one of two values, + 1 / -1. The serving cell control information determiner 1010 interprets the HSDPA serving cell switching control signal received from the serving cell switching control information extractor 1008 according to the rules of Table 2 above. The power control information obtained according to the analysis is applied to set the transmission power of the serving cell switching recognition signal.

Third Embodiment

In the first and second embodiments of the present invention, a method of adjusting the transmission power of the serving cell switch acknowledgment signal is proposed to increase the reliability of the serving cell switch acknowledgment signal transmitted by the UE. The third embodiment of the present invention proposes another method for increasing the reliability of the serving cell switch recognition signal. That is, the target cell instructs the UE to repeatedly transmit the serving cell switch acknowledgment signal a predetermined number of times according to an uplink channel state. Accordingly, the target cell may receive additional serving energy as many times as the UE repeatedly transmits the serving cell switch acknowledgment signal, thereby successfully receiving the serving cell switch acknowledgment signal even when the uplink channel state is not good. Specifically, the target cell transmits the serving cell switch acknowledgment signal M times when the uplink channel state is good to the UE, and transmits the serving cell switch acknowledgment signal N times when the uplink channel state is not good. . Wherein M and N are integers greater than 0, and N is an integer greater than M. The serving cell switch acknowledgment signal can be notified by using a specific codeword of CQI control information for supporting a conventional HSDPA, or by changing an uplink scrambling code or inserting into uplink data. Information on the number of transmissions of the serving cell switch acknowledgment signal that the target cell notifies the UE is inserted into the conventional HS-SCCH and transmitted.

Hereinafter, referring to FIG. 6, a method of inserting information about the number of transmissions of the serving cell switch acknowledgment signal according to the third embodiment of the present invention into an HS-SCCH will be described. As described in the first embodiment of the present invention, part of the control information of the conventional HS-SCCH is used by using a predetermined fixed value, and the part of the control information is used for instructing the DRX and DTX operations. . In the third embodiment of the present invention, the HS-SCCH defined for the above uses is called an HS-SCCH order channel.

In addition, in the third embodiment of the present invention, for convenience, a control channel for transmitting information about the transmission frequency of the HSDPA serving cell switching indicator and the serving cell switching acknowledgment signal in which the HS-SCCH order channel is modified is called an HSDPA serving cell switching indication channel. Shall be. The HSDPA serving cell switch indication channel operates independently without involving the HSDPA data channel.

The HSDPA serving cell switch indication channel is composed of 37 bits in total like the conventional HS-SCCH and HS-SCCH order channels. The first 8 bits 602 are bits corresponding to 7 bits of information on the OVSF codes of the conventional HS-SCCH and 1 bit of a modulation scheme to be applied to the HSDPA data, and use a fixed value of the first predetermined pattern. The first predetermined pattern is '11100000'. The six bits 604 after the eight bits 602 are bits corresponding to six bits of the HSDPA data size of the conventional HS-SCCH, and use a fixed value of the second predetermined pattern. The second predetermined pattern is '111101'. The 3 bits 606 after the 6 bits 604 are bits corresponding to 3 bits of the HARQ process number of the conventional HS-SCCH, and use a fixed value of a third predetermined pattern. The predefined third pattern is '000'. The 3 bits 608 after the 3 bits 606 are bits corresponding to the redundant versions of the data to be transmitted through the HSDPA of the conventional HS-SCCH, and indicate DRX and DTX operations or HSDPA serving cell switching indicator and serving. It is used to indicate the transmission frequency information of the cell switch acknowledgment signal.

The interpretation method of the 3 bits 608 is shown in Table 3.

bb1, b2 b3 Translate XX 0 Performing the DTX and DRX Operation of the conventional HS-SCCH order 00 One Transmission count information # 1 of HSDPA serving cell switch indication and serving cell switch acknowledgment signal 01 One Transmission count information # 2 of HSDPA serving cell switch indication and serving cell switch acknowledgment signal 10 One Transmission count information # 3 of HSDPA serving cell switch indication and serving cell switch acknowledgment signal 11 One Transmission count information # 4 of HSDPA serving cell switch indication and serving cell switch acknowledgment signal

According to Table 3, DTX and DRX operations according to the conventional HS-SCCH order defined according to the values of b1 and b2 when b3 = 0 according to the value of b3 among the three bits 608 b1, b2 and b3. When b3 = 1, HSDPA serving cell switching is instructed, and the number of times of transmission of the serving cell switching recognition signal is additionally provided according to the values of b1 and b2.

That is, if <b1, b2, b3> = <0,0,1>, HSDPA serving cell switching is indicated, transmission number information # 1 of the serving cell switching acknowledgment signal is indicated, and <b1, b2, b3> = If <0,1,1>, HSDPA serving cell switching is indicated, and transmission frequency information # 2 of the serving cell switching acknowledgment signal is indicated, and if <b1, b2, b3> = <1,0,1>, HSDPA Instructs serving cell switching, indicates transmission frequency information # 3 of the serving cell switching acknowledgment signal, and if <b1, b2, b3> = <1,1, 1>, indicates HSDPA serving cell switching, and serving cell switching The transmission frequency information # 4 of the acknowledgment signal is indicated.

The number of transmission information # 1, # 2, # 3, and # 4 of the serving cell switch acknowledgment signal are different values previously promised, and the number of times of transmission of the serving cell switch acknowledgment signal transmitted by the UE is changed from the UE to the target cell. The target cell determines the value according to the uplink channel state. That is, as the uplink channel state from the UE to the target cell is poor, the target cell sets the transmission frequency of the serving cell switch acknowledgment signal to the UE and instructs the UE to transmit the serving cell as indicated by the target cell. Transmit acknowledgment signal is transmitted to the target cell.

In FIG. 6, one bit of reference numeral 610 is a value corresponding to one bit of a new data identifier of the conventional HS-SCCH and is left unused in the HSDPA serving cell switching indication channel. The UE-ID specific CRC of the reference numeral 612 is generated by performing an XOR operation on the CRC 16 bits generated by inputting the above-described control information 602, 604, 606, 608, 610 with the UE-ID 16 bits.

The base station transmitter according to the third embodiment of the present invention follows the description of FIG. 7. However, in the third embodiment of the present invention, the power control information of the serving cell switch indication channel in FIG. 7 is replaced with the transmission count of the serving cell switch acknowledge signal, and the generation of the transmission count of the serving cell switch acknowledge signal is shown in Table 3 below. Follow>

In addition, the terminal receiving apparatus according to the third embodiment of the present invention follows the description of FIG. 8. However, in the third embodiment of the present invention, the power control information of the serving cell switch indication channel in FIG. 8 is replaced with the transmission count of the serving cell switch acknowledge signal, and the analysis of the transmission count of the serving cell switch acknowledge signal is shown in Table 3 below. Follow>

In another implementation method of the third embodiment of the present invention, the transmission count information of the HSDPA serving cell switch indicator and the serving cell switch acknowledgment signal may be defined as one bit of reference number 610 instead of three bits of reference number 608 in FIG. 6. have. In this case, the transmission count information of the HSDPA serving cell switch indicator and the serving cell switch acknowledgment signal may be defined as two types. For example, when 1 bit of the reference number 610 is '0', the HSDPA serving cell switching indication is instructed and the number of transmissions of the serving cell switching acknowledgment signal of the UE is applied as much as the transmission number information # 1 of the serving cell switching acknowledgment signal. If 1 bit of reference numeral 610 is '1', it may indicate HSDPA serving cell switching and apply the number of transmissions of the serving cell switching acknowledgment signal of the UE by the number of transmissions # 2 of the serving cell switching acknowledgment signal.

Claims (4)

In the method for transmitting control information in a mobile communication system, Receiving, by the wireless network controller, a measurement report on a downlink channel state from a terminal, and determining to switch a serving cell for the terminal from a source cell to a target cell according to the measurement report content; Instructing the radio network controller to perform serving cell switching between the source cell and the serving cell, and transmitting data to be transmitted to the terminal to the source cell and the destination cell; Transmitting, by the target cell, power control information on a serving cell switching indicator and an uplink signal to the terminal; And receiving, by the target cell, a response signal for switching a serving cell from the terminal, and performing data communication with the terminal. In the method for receiving control information in a mobile communication system, Transmitting, by the terminal, a measurement report on a downlink channel state to a source cell; Receiving, by the terminal, a serving cell switching indicator and power control information for uplink from a target cell, and transmitting a response message to which the power control information is applied to the target cell; And receiving, by the terminal, data communication with the target cell. An apparatus for transmitting control information in a mobile communication system, A serving cell switch controller for determining whether to switch a serving cell according to uplink channel state information received from a terminal; A control information generator for generating control information for serving cell switching, a serving cell switching indicator, and uplink power control information according to the determination of the serving cell switching controller; And a transmitter for encoding, multiplexing and transmitting the generated control information, a serving cell switching indicator, and uplink power control information. An apparatus for receiving control information in a mobile communication system, A control information obtainer for obtaining serving cell switching control information from the received signal; And a serving cell switching controller configured to determine validity of control information acquired by the control information obtainer and to set uplink transmission power according to the control information if the control information is valid.