JP2000091970A - Radio base station device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio base station device in a radio base station where plural radio devices use an antenna in common where transmission quality of an outgoing channel is enhanced without increasing transmission power. SOLUTION: A signal quality value at each branch (antenna) obtained by a diversity reception section 501 of each of radio devices 51, 52,... in a TDD radio base station at reception is given to an antenna changeover control section 7, and each one transmission antenna is selected for each radio device so as not to be in duplicate among the radio devices. The antennas are selected such that signal quality of a radio device with the lowest signal quality is enhanced to the utmost among each combination between each antenna and each radio device in the selection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio base station apparatus for communicating with a mobile or fixed terminal via a radio channel.

[0002]

2. Description of the Related Art In recent years, the spread and digitization of public mobile communications represented by cellular phones and personal handy phones have been rapidly progressing. As a standard of a mobile radio communication system that performs communication via a base station or a radio section of a wireless local loop (WLL) that accommodates a fixed telephone in a house by a radio line, for example, the standard R of the Association of Radio Industries and Businesses
CR STD-28 with personal handy phone (PH
S) is specified. And the above PHS
A time division duplex transmission (TDD) for communicating a radio wave from the base station to the mobile station (hereinafter, referred to as “downlink”) and a radio wave from the mobile station to the base station (hereinafter, referred to as “uplink”) at the same frequency in a time division manner. ) Communicates. As a multiple access system, a combination of time division (TDMA) and frequency division (FDMA) is used.

[0003] In mobile communication, fading generally occurs, and the transmission quality, that is, the bit error rate characteristic is greatly deteriorated. Also, in WLL which is a fixed communication, fading is observed due to a temporal change of a propagation environment such as an automobile. As a method of compensating for deterioration of transmission quality due to fading, diversity reception is generally used.

[0004] However, diversity receivers that perform diversity reception are often used in base stations because of their complex structure, but are not preferred for use in terminal devices that require small size and low power consumption. As a method for solving this problem, there is transmission selection diversity. Transmission selection diversity is transmission in a TDD wireless system using a diversity branch (antenna) having the best reception quality at the time of reception immediately before transmission. Therefore, if diversity reception is performed at the base station and transmission selection diversity is performed, the effect of fading can be reduced for both the upper and lower channels without performing diversity at the mobile station. In particular, when fading such that the mobile station moves at about the walking speed is slow, the effect of the transmission selection diversity is equivalent to the effect of diversity reception by selective combining.

In the PHS, as described in detail in Ogawa / Kobayashi, edited by the Telecommunications Association, the third edition, "Easy Personal Handy Phone", diversity reception at the base station and the best reception condition at the time of reception were obtained. A radio channel design has been made on the assumption that transmission selection diversity for selecting an antenna as a next transmission antenna is performed.

In consideration of installation costs and ease of maintenance, it is preferable to increase the radius of the service zone per base station. However, in this case, the traffic volume per base station also increases. It is necessary to increase the number of wireless channels that can be simultaneously connected. In order to increase the number of the same radio channels beyond the number of TDMA multiplexes, it is necessary to mount a plurality of radios (transceivers) for simultaneous transmission and reception at a plurality of carrier frequencies. Therefore, when using independent and independent antennas for each wireless device, KN antennas are required if the number of diversity branches is K and the number of wireless devices is N. Therefore, when K and N are large, for example, K
= 4, N = 3, as many as 12 antennas are required, and the base station equipment becomes large, which is not preferable. An antenna can be shared between wireless devices by a hybrid circuit or the like, but a loss of 3 dB or more occurs in the antenna shared circuit. For this reason, especially, the transmission high-frequency power amplifier becomes large and the power consumption increases.

[0007] For this reason, in the conventional radio base station apparatus, reference is made to the literature (Kobayashi, Ogoshi, "Study on selective antenna shared diversity transmission", IEICE General Conference, 1997,
This problem has been solved by the method disclosed in 5-105). In the configuration of the radio base station apparatus disclosed in the above document, each radio device shares an antenna between radio devices by a hybrid circuit or the like during reception, but two specific radio channels determined for each radio device during transmission. The antenna (branch) is selected so as not to overlap between the wireless devices under a certain rule. Therefore, it is not necessary for the transmission signal to pass through a hybrid circuit or the like, and the above-mentioned configuration is such that the loss of 3 dB does not occur.

As described above, in the conventional radio base station apparatus of the TDD system, the transmission quality is improved and the communicable area is expanded by performing diversity reception and transmission diversity.

[0009]

However, in the above-mentioned conventional radio base station apparatus, three or more antennas are mounted and diversity reception with three or more branches can be performed during reception. There are only two antennas to which transmission signals can be connected, and only the effect of transmission selection diversity of two branches can be obtained. For this reason, the diversity gain at the time of transmission is significantly lower than the diversity gain at the time of reception, so that the transmission power must be set high, power consumption increases, and it becomes difficult to reduce the size of the device. Was.

[0010] It is an object of the present invention to solve the above-mentioned problems and to provide a radio base station apparatus capable of improving the diversity gain at the time of transmission and improving the transmission quality of the downlink without increasing the transmission power.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a transmission antenna selection switch for selecting and connecting an antenna for supplying a transmission signal of each of a plurality of radios from all antennas used for reception. An antenna changeover switch connected to each of the antennas for selecting and connecting a reception signal output and a transmission signal input of the plurality of radios connected via the transmission antenna selection switch, so that diversity at the time of transmission is provided. It is possible to provide a radio base station apparatus capable of improving gain and improving downlink transmission quality without increasing transmission power.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, there are provided a plurality of antennas, a plurality of radios having the same number as the number of the plurality of antennas, and a plurality of radios. A transmission antenna selection switch that selects and connects an antenna that supplies a signal from the plurality of antennas,
An antenna changeover switch connected to each of the plurality of antennas, for selecting and connecting a reception signal output and a transmission signal input of the plurality of radios connected via the transmission antenna selection switch, The switch and the antenna changeover switch are controlled so that the transmission signals of each of the plurality of radios are connected to any one of the plurality of antennas without overlapping each other at the time of transmission. This has the effect of increasing the equivalent number of branches and improving the diversity gain during downlink transmission.

According to a second aspect of the present invention, there are provided a plurality of antennas, a plurality of radios whose number is equal to or less than the number of the plurality of antennas, and a transmission signal for each of the plurality of radios. A transmission antenna selection switch for selecting and connecting an antenna to be selected from a plurality of antennas, and selecting a reception signal output and a transmission signal input of a plurality of radios connected via the transmission antenna selection switch connected to each of the plurality of antennas An antenna change-over switch connected to the transmission antenna selection switch and the antenna change-over switch, the transmission signal of each of the plurality of radios being overlapped with any one of a plurality of antennas at the time of transmission. And the plurality of radios each determine a received signal quality value for each of the plurality of antennas. Means for issuing a signal, and assigning any one of the plurality of antennas to each of the plurality of radios without overlapping each other. Antenna switching control for finding a pair, selecting the combination having the highest signal quality value by comparing these signal quality values through all combinations, and controlling the transmission antenna selection switch and the antenna switching switch according to the result. The antenna to which the transmission signal from each radio is supplied is selected so that the transmission quality in each radio is as high as possible, the equivalent number of branches in transmission selection diversity increases, This has the effect of improving the diversity gain during line transmission.

According to a third aspect of the present invention, there are provided a plurality of antennas, a plurality of radios having the same number as the number of the plurality of antennas, and a transmission signal for each of the plurality of radios. A transmission antenna selection switch for selecting and connecting an antenna from a plurality of antennas, and selecting a reception signal output and a transmission signal input of a plurality of radios connected via the transmission antenna selection switch to each of the plurality of antennas. An antenna change-over switch connected to the transmission antenna selection switch and the antenna change-over switch. The transmission antenna selection switch and the antenna change-over switch connect the transmission signals of the plurality of wireless devices to any one of the plurality of antennas at the time of transmission without overlapping each other. And the plurality of radios each detect an error rate of transmission data for each of the plurality of antennas. Or a radio device having the highest error rate of transmission data for each combination, in a case where any one of a plurality of antennas is assigned to each of the plurality of radio devices without overlapping each other. And an antenna pair for selecting the combination having the lowest error rate by comparing these error rates across all combinations, and controlling the transmission antenna selection switch and the antenna switch according to the result. With the control unit, the equivalent number of branches in transmission selection diversity increases, and the antenna to which the transmission signal from each radio is supplied has a transmission quality in each radio, that is, an error rate of transmission data. Since it is selected to be as low as possible, diversity gain during downlink transmission is improved. It has the effect of.

According to a fourth aspect of the present invention, there are provided a plurality of antennas, a plurality of radio units having the same or less number as the number of the plurality of antennas, and a transmission signal for each of the plurality of radio units. A transmission antenna selection switch for selecting and connecting an antenna from a plurality of antennas, and selecting a reception signal output and a transmission signal input of a plurality of radios connected via the transmission antenna selection switch to each of the plurality of antennas. Antenna transmission switch, and the transmission antenna selection switch and the antenna transmission switch are connected to each other so that transmission signals of the plurality of radios do not overlap each other on any one of the plurality of antennas during transmission. Are controlled to be connected, and the plurality of radios are each configured to have an error rate of transmission data for each of the plurality of antennas. Means for detecting or estimating, wherein when any one of the plurality of antennas is assigned to each of the plurality of radio devices without overlapping each other, the error rate of transmission data is summed up for each combination. And a combination that minimizes the sum, selects an antenna switching control unit that controls the transmission antenna selection switch and the antenna selection switch according to the result, and provides an equivalent branch in transmission selection diversity. The number of antennas to which the transmission signal is supplied from each radio is increased, and the transmission quality, that is, the average error rate of the transmission data between the radios is selected as low as possible. This has the effect of improving the diversity gain.

According to a fifth aspect of the present invention, in the wireless base station apparatus according to the second aspect, when the number of the plurality of antennas is K, the number of antennas in each of the plurality of radios is K A first table in which the received signal quality values are arranged in descending order of the received signal quality values, a second received signal quality value of the first table is compared between the radios, and a first table having the lowest value is generated. The first
The first antenna having the first received signal quality value in the table is selected from the plurality of antennas and assigned, and from the first table in each of the plurality of radios except for the first radio. Generating a second table excluding the one for the first antenna, comparing a second received signal quality value of the second table between the radios, a second radio having the lowest value; The second
By selecting a second antenna having the first received signal quality value from the plurality of antennas and allocating the second antenna, the transmission antenna selection switch and the antenna switch are controlled according to the allocation. An antenna to which a transmission signal from each wireless device is supplied is selected by a simple algorithm, and has an effect that a diversity gain at the time of downlink transmission is improved.

According to a sixth aspect of the present invention, in the wireless base station apparatus according to the third aspect, when the number of the plurality of antennas is K, each of the plurality of radios has a K number corresponding to each of the plurality of antennas. A first table in which the transmission data error rates are arranged in ascending order, and
The second received signal quality value of the table is compared between the wireless devices, and the first transmitted data error of the first table is compared with the first wireless device having the highest value of the transmission data error rate. Selecting and assigning a first antenna having a ratio from the plurality of antennas, excluding the antenna for the first antenna from the first table in each of the plurality of radios except the first radio The second transmission data error rate of the second table is compared between the wireless devices, and the second transmission device having the highest value of the transmission data error rate is compared with the second wireless device having the highest value. The second antenna having the first data error rate in the second table is selected from the plurality of antennas and assigned, so that the transmitting antenna selection switch and the previous antenna are switched according to the assignment. Are those antenna changeover switch is controlled, is the antenna selection signal transmitted from the radio is provided by a simple algorithm, it has the effect of improving diversity gain when transmitting downlink.

According to a seventh aspect of the present invention, there is provided the radio base station apparatus according to the second, third, fourth or fifth aspect, wherein communication is not set during the reception period. Excluding the received signal quality value or the data error rate in the wireless device and the communication is not set, the transmission antenna for each wireless device, selecting from the plurality of antennas and allocating,
Since the number of equivalent diversity branches at the time of transmission in a radio device other than the radio device for which the communication is not set increases, the diversity gain at the time of downlink transmission is improved.

According to an eighth aspect of the present invention, in the wireless base station apparatus according to the second, third, fourth or fifth aspect, all of the received signal quality values in the receiving period In the low signal quality radio which is equal to or less than a predetermined value for the plurality of antennas, or in which the data error rate is equal to or more than a predetermined value for all the plurality of antennas, Excluding the received signal quality value or the data error rate, the transmitting antenna for each radio is selected from the plurality of antennas and assigned, and when transmitting in a radio other than the low signal quality radio. Has the effect of improving the diversity gain at the time of downlink transmission because the equivalent number of diversity branches increases.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Hereinafter, the number of wireless devices is represented by N, the number of antennas is represented by K, and N ≦ K.

(Embodiment 1) FIG. 1 is a block diagram of a radio base station apparatus using TDD communication according to an embodiment of the present invention. The figure shows the number of wireless devices N = 3, the number of antennas K =
Although the example of No. 4 is shown, the following description is exactly the same if 2 ≦ N ≦ K. In FIG. 1, 11, 12,
Reference numerals 13 and 1K denote antennas, respectively, which constitute a K-diversity branch. Generally, the omnidirectional one in the horizontal plane is used,
For example, a directional antenna may be used in the case of a sectorized cell or the like or when configuring directional diversity.

Reference numerals 21, 22, 23 and 2K denote antenna changeover switches for switching the radio equipment connected for transmission / reception and transmission for each antenna. Reference numeral 3 denotes a high-frequency low-noise amplifier (hereinafter, referred to as LNA). The high frequency low noise amplifier 3 is provided individually for each antenna,
A signal received by an antenna is amplified for each antenna. 4
Denotes a distributor, which is individually provided for each antenna. The reception signal received by the antenna 1 and amplified by the LNA 3 is distributed to N signals.

Reference numerals 51, 52, and 5N denote radio units, and a total of N units are provided. These radio devices are composed of a diversity receiving unit 501 and a transmitting unit 502 of the K branch, and a control unit 503 for performing data processing of transmission / reception signals and controlling connection with a telephone line. Note that the diversity receiving section 501 has a function of detecting the received signal quality of each branch (here, each antenna). As the received signal quality, for example, an RSSI value indicating the received signal strength can be easily obtained.

61, 62,. . . 6N is a transmission antenna selection switch, which is an antenna selection switch 21,
2,. . . 2K, and each of the wireless devices 51, 52,. . .
Antennas used for transmission every 5N are antennas 11, 1
2,. . . One of the 1K K lines is selected and connected.
Reference numeral 7 denotes an antenna switching control unit which compares the reception signal qualities of the respective antennas of the respective radios and determines the transmission antenna selection switches 61, 62,. . . 6N and antenna changeover switches 21, 22,. . . 2K is controlled.

The operation of the radio base station apparatus configured as described above will be described below. First, at the time of reception, all antenna changeover switches 21, 22,. . . 2K is connected to terminal R, and antennas 11, 12,. . . 1K is transmitted via the LNA 3 and the distributor 4 to each of the radios 51, 52,. . . 5N diversity receiver 501
Is input to The received signal is transmitted to each of the wireless devices 51, 52,. . .
After diversity combining / demodulation is performed by the diversity receiving unit 501 every 5N, signal processing required by the control unit 503 is performed.
For example, the data is subjected to format conversion, error detection / correction, etc., and sent to a telephone line, that is, a network. At this time, the diversity receiving section 501 detects the received signal quality of each antenna and sends the signal quality value to the antenna switching control section 7.

Next, the antenna switching control unit 7 compares the received signal quality of each radio and each antenna, and, like the antenna selection transmission diversity, the branch whose received signal quality was good at the time of the immediately preceding reception, ie, the branch. An antenna is selected for each radio and used for transmission.

However, in the configuration of the radio base station according to the present invention, the antennas 11, 12,. . . Since 1K is shared, the antennas having the best signal quality may overlap between wireless devices. In this case, one of the wireless devices selects the antenna having the second or higher signal quality based on the criteria described below.

That is, each of the wireless devices 51, 52,. . . 5
N transmitting antennas 11, 12,. . . From 1K, when assigning one by one so as not to overlap between radios,
The signal quality value of the wireless device having the lowest signal quality value for the assigned antenna is evaluated, and a combination of each wireless device and each antenna is determined so that the signal quality value becomes high. If there are a plurality of such combinations, the signal quality for the antenna assigned among them is 2
Evaluate the signal quality value of the next lowest radio and determine the combination with the highest signal quality value. Further, when there are a plurality of combinations, the third and fourth lowest signal quality values are similarly evaluated, and the combination having the highest signal quality value is determined. Hereinafter, a specific example of the operation will be described, taking as an example the case where the signal quality values shown in FIG. 2 and (Table 1) are obtained.

[0029]

[Table 1]

The combination of the transmitting antenna and the radio is N! / (NK)! There are only streets. However! Indicates a factorial operation. In this example, 4 × 3 × 2 = 24 patterns. Table 2 shows these combinations and the signal quality values in each wireless device.

[0031]

[Table 2]

Then, the signal quality value of the wireless device having the lowest signal quality value is checked for each combination. In Table 2, the signal quality value of the wireless device having the lowest signal quality value for each combination is marked with a triangle. For example, in the first combination (the column of combination number 1), the wireless device 53 is connected to the antenna 1
3, the signal quality value is 30 which is the lowest, and in the second combination, the wireless device 53 is connected to the antenna 14.
Is the lowest signal quality value when connected to 15,
In the third combination, the wireless device 52 is connected to the antenna 13.
Is 75, which is the lowest signal quality value.

Next, the signal quality value (信号) throughout the table
Are compared, and the combination having the highest signal quality value is selected, which is clearly the fifth combination from the table (combination number: 5). That is, the wireless device 51 is the antenna 1
1, the antenna 52 is selected by the antenna switching control unit 7 as the transmission antenna, and the antenna 52 is selected as the transmission antenna.

Then, at the time of transmission, the antenna switching control unit 7 controls the transmission antenna selection switches 61, 62,. . . 6N and antenna changeover switches 21, 22,. . . 2K is switched, and a radio wave is transmitted. (Table 1) and (Table 2) above
In the case of the example shown in FIG.
2,. . . 2K are transmission antenna selection switches 61, 62,. . . 6N are connected as indicated by arrows in FIG.

It is to be noted that, even when the diversity receiving section 501 can obtain a transmission data error rate such as a bit error rate for each branch (antenna) as a received signal quality value, the same radio base station apparatus as in the present embodiment can be used. Can be configured. The transmitted data error rate can be evaluated on known data portions that are often inserted into the transmitted signal for synchronization or other purposes. In this case, each of the wireless devices 51, 52,. . . The 5N transmitting antennas are connected to antennas 11, 12,. . . From 1K
When one radio is assigned so as not to overlap between the radios, the signal quality value of the radio having the highest data error rate for the assigned antenna is evaluated. What is necessary is just to determine the combination of antennas.

For example, if the data error rate shown in (Table 3) is obtained at the time of reception, the worst error rates marked with a triangle from among the 24 combinations shown in (Table 4) are compared. The combination with the lowest error rate (error rate: 0.01), that is, the fifth combination is selected from those marked with a triangle. The use of the error rate as the evaluation criterion is effective when the signal quality evaluation value such as RSSI is not necessarily proportional to the signal quality, for example, when interference or interference is received.

[0037]

[Table 3]

[0038]

[Table 4]

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described. This embodiment corresponds to the first embodiment shown in FIG.
This is the same configuration as that of the embodiment. However, the diversity receiving section 501 obtains a transmission data error rate such as a data error rate for each branch (antenna) as a received signal quality value. Then, in the antenna switching control unit 7, each of the wireless devices 51, 52,. . . The 5N transmitting antennas are connected to antennas 11, 12,. . . From 1K, when assignments are made one by one so as not to overlap between the radios, the average value of the data error rates for the assigned antennas among the N radios is evaluated. Then, the combination of the antenna and the radio having the lowest average is selected, and the transmission antenna selection switches 61, 62,. . . 6N and antenna changeover switches 21, 22,. . . 2K is switched, and a radio wave is transmitted.

For example, (Table 3) When the error rate is obtained, there are 24 combinations shown in (Table 4). N times the average error rate of each combination, that is, the sum of the error rates between the wireless devices is the value shown in the rightmost column of the table, and the fifth combination that gives the lowest value among these is selected. That is, the wireless device 51 is the antenna 11 and the wireless device 52
Is selected by the antenna switching control unit 7 with the antenna 14 as the transmitting antenna and the antenna 53 as the transmitting device. By using the average error rate as the evaluation criterion in this way, the overall signal quality can be improved.

(Embodiment 3) Hereinafter, a third embodiment of the present invention will be described. This embodiment is also the first in FIG.
The configuration is the same as that of the first embodiment, and operates in the same manner as the first embodiment, except for a transmission antenna assignment algorithm for each wireless device in the antenna switching control unit 7.

Hereinafter, the assignment algorithm will be described. First, each of the wireless devices 51, 52,. . . Every 5N, each antenna 11, 12,. . . A first table is generated in which K signal quality values for 1K are arranged in descending order.
For example, in the case of the signal quality values in (Table 1), (Table 5) (a)
Is obtained.

[0043]

[Table 5]

In Table 5, for example, when looking at the radio 53, since the signal quality is highest when combined with the antenna 12 (signal quality value: 115), the combination with the antenna 12 comes first in the ranking. . Also, since the signal quality is the lowest when combined with the antenna 14 (signal quality value: 15), this combination comes fourth in the ranking.
Similarly, for the other radios 51 and 52, the signal quality values for each antenna are arranged in descending order.

The allocation algorithm here first compares the signal quality values of the second rank in the tables of (Table 5) and (a) among the radios, and compares the radio quality with the lowest value with the rank in the table. The antenna having the first signal quality value is selected and assigned.

For example, in (Table 5) (a), among the signal quality values of the second rank, the one of the wireless device 53 marked with ▲ is the lowest (signal quality value: 30). An antenna is assigned to the wireless device 53. That is, for the wireless device 53, the antenna 12 having the first signal quality value is selected and assigned.

Next, as shown in (Table 5) and (c), the K for each antenna is again determined for each radio as shown in (Table 5) and (c), except for the radios already allocated and the allocated antennas as shown in (Table 5) and (b).
A second table in which -1 signal quality values are arranged in descending order is generated. Then, the second-ranked signal quality value in the same table is compared again between the wireless devices, and the antenna having the first-ranked signal quality value in the same table is selected and assigned to the wireless device having the lowest value. For example, in (Table 5) (c), the signal quality value of the second rank is ▲
The one with the radio 51 attached with is the lowest (signal quality value: 50)
Therefore, the antenna 11 having the first signal quality value is selected and assigned to the wireless device 51.

In the case of N> 3, this procedure may be repeated as follows. For the last remaining radio, (Table 5)
As shown in (d), the antenna with the higher signal quality is assigned. As described above, in the present embodiment, it is not necessary to evaluate all combinations of the antenna and the wireless device, so that the amount of calculation in the antenna switching control unit 7 is reduced.

In any of the above embodiments,
If communication has not been set during the reception period,
For a low signal quality radio whose received signal quality value is less than or equal to a predetermined value for all antennas, or whose data error rate is greater than or equal to a predetermined value for all antennas, the same radio and Excluding the signal quality value or data error rate in the wireless device, the antenna switching control unit 7
, The transmission antennas may be assigned. In other words, when the reception state of any antenna is poor in a specific wireless device, for example, when an antenna is assigned to any antenna in voice transmission, an error rate of 0.01 or less or a signal strength that is expected to be the same is not obtained. , The transmitting antenna is first allocated by a radio device other than the radio device. By doing so, in the radio equipment other than the low signal quality, the probability that the antenna having the best signal quality value is assigned increases, and the communication quality as a whole improves.

Although each of the above embodiments has been described with respect to a base station for TDD communication, it can be applied to FDD (frequency division duplex) as follows. For example, the transmitting antenna of the base station is switched during a period in which information such as a preamble is not mounted, and the mobile station notifies the signal quality of each transmitting antenna. Switching of the transmitting antenna
11, 12, 13, 14 for the wireless device 51, 1 for the wireless device 52
2, 13, 14, 11, 13, 53, 13, 14, 11,
If it is performed in the order of 12, it is possible without duplication. Then, using the signal quality value notified from the mobile station, the antenna switching control unit 7 may select and control the next transmission antenna.

[0051]

According to the present invention, in a radio base station apparatus equipped with a plurality of radios, the transmission antenna of each radio can be selected from all the mounted antennas. And the diversity gain is improved. In addition, since there is no antenna shared circuit such as a hybrid circuit in the transmission system and the antenna is shared between the wireless devices by simple switching, the loss of transmission power is small.

Further, for a radio having a poor signal quality value regardless of which antenna is used for transmission, a radio other than the radio is assigned a transmission antenna first so that transmission by another radio can be performed. The diversity gain is improved, and the communication quality as a whole is improved. Therefore, it is possible to provide an excellent radio base station apparatus capable of improving downlink transmission quality without increasing transmission power.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a radio base station apparatus according to an embodiment of the present invention.

FIG. 2 is a bar graph showing an example of signal quality in each wireless device.

[Explanation of symbols]

 11, 12, 13, 1K antenna 21, 22, 23, 2K antenna changeover switch 3 High frequency low noise amplifier (LNA) 4 Divider 51, 52, 5N radio 501 Diversity receiver 502 Transmitter 503 Controller 61, 62, 6N transmission antenna selection switch 7 antenna switching control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K059 AA12 CC02 DD04 DD16 DD27 EE03 5K067 AA02 BB02 CC24 EE10 HH21 KK03

Claims (8)

[Claims] 1. A plurality of antennas, a plurality of radios whose number is equal to or less than the number of the plurality of antennas, and an antenna for supplying a transmission signal of each of the plurality of radios are selected from the plurality of antennas. A transmission antenna selection switch to be connected, and an antenna selection switch connected to each of the plurality of antennas for selecting and connecting a reception signal output and a transmission signal input of the plurality of radios connected via the transmission antenna selection switch. The transmission antenna selection switch and the antenna changeover switch,
A radio base station comprising: an antenna switching control unit that controls transmission signals of each of the plurality of wireless devices to be connected to any one of the plurality of antennas without overlapping each other during transmission. apparatus. 2. A plurality of antennas, a plurality of radios whose number is equal to or less than the number of the plurality of antennas, and an antenna for supplying a transmission signal of each of the plurality of radios are selected from the plurality of antennas. And a transmission antenna selection switch connected to each of the plurality of antennas, and an antenna switch for selecting and connecting a reception signal output and a transmission signal input of the plurality of radios connected via the transmission antenna selection switch. A transmission antenna selection switch and the antenna changeover switch, so that transmission signals of the plurality of wireless devices are connected to any one of the plurality of antennas without overlapping each other during transmission. Wherein said plurality of radios each comprise means for detecting a received signal quality value for each of said plurality of antennas. Then, when any one of the plurality of antennas is assigned to each of the plurality of radios without overlapping each other, a radio and antenna pair having the lowest signal quality value is searched for each combination. An antenna switching control unit that selects the combination having the highest signal quality value by comparing these signal quality values through all combinations, and controls the transmission antenna selection switch and the antenna switching switch according to the result. A wireless base station device. 3. A plurality of antennas, a plurality of radios whose number is equal to or less than the number of the plurality of antennas, and an antenna for supplying a transmission signal of each of the plurality of radios are selected from the plurality of antennas. A transmission antenna selection switch to be connected, and an antenna selection switch connected to each of the plurality of antennas for selecting and connecting a reception signal output and a transmission signal input of the plurality of radios connected via the transmission antenna selection switch. The transmission antenna selection switch and the antenna selection switch are controlled so that transmission signals of the plurality of wireless devices are connected to any one of the plurality of antennas without overlapping each other during transmission. The plurality of radios, each of which detects an error rate of transmission data for each of the plurality of antennas or Means for assigning any one of the plurality of antennas to each of the plurality of radios without overlapping each other, wherein the radio having the highest error rate of transmission data for each combination is provided. An antenna for controlling the transmission antenna selection switch and the antenna changeover switch according to the result by searching for a pair of a transmitter and an antenna, selecting a combination having the lowest error rate by comparing these error rates through all combinations, and A wireless base station device comprising a switching control unit. 4. A plurality of antennas, a plurality of radio units whose number is equal to or less than the number of said plurality of antennas, and an antenna for supplying a transmission signal of each of said plurality of radio units are selected from said plurality of antennas. A transmission antenna selection switch to be connected, and an antenna selection switch connected to each of the plurality of antennas for selecting and connecting a reception signal output and a transmission signal input of the plurality of radios connected via the transmission antenna selection switch. The transmission antenna selection switch and the antenna selection switch are controlled so that transmission signals of the plurality of wireless devices are connected to any one of the plurality of antennas without overlapping each other during transmission. The plurality of radios, each of which detects an error rate of transmission data for each of the plurality of antennas or And means for constant, the sum of the error rate of the transmission data any one of the plurality of antennas to the plurality of radios, each when performing assignment without overlapping each other, each combination,
A radio base station apparatus comprising: an antenna switching control unit that selects a combination that minimizes the sum and controls the transmission antenna selection switch and the antenna switching switch according to the result. 5. When a number of said plurality of antennas is K, a first table is generated in each of said plurality of radios, in which K received signal quality values for each of said plurality of antennas are arranged in descending order. , Comparing the second received signal quality value in the first table between the radios, and comparing the first received radio signal quality value in the first table to the first radio having the lowest value.
A first antenna having a second received signal quality value is selected from the plurality of antennas and assigned, and the first antenna is selected from the first table in each of the plurality of radios except for the first radio. Generating a second table excluding the one for the antenna, comparing the second received signal quality value of the second table between the radios, and comparing the second received signal quality value for the second radio with the lowest value; 1 of the second table
3. The radio base according to claim 2, wherein a second antenna having a third received signal quality value is selected from the plurality of antennas to determine a combination, and the transmission antenna selection switch and the antenna changeover switch are controlled based on the result. Station equipment. 6. When a number of the plurality of antennas is K, a first table in which K transmission data error rates for each of the plurality of antennas are arranged in ascending order in each of the plurality of antennas is generated. , 2 of the first table
The first received signal quality value is compared between the wireless devices, and the first wireless device having the highest transmission data error rate has the first transmission data error rate in the first table for the first wireless device. One antenna is selected from the plurality of antennas and assigned, and a second table obtained by removing one for the first antenna from the first table in each of the plurality of radios except the first radio is described. Generating a table, comparing the second transmission data error rate of the second table between the wireless devices, and comparing the second transmission data error rate to the second wireless device having the highest value. The second antenna having the first data error rate in the table is selected from the plurality of antennas to determine a combination, and based on the result, the transmission antenna selection switch and the antenna changeover switch are set. Gosuru claim 2 or claim 3 radio base station apparatus according. 7. Excluding a reception signal quality value or a data error rate in a radio in which communication is not set in the reception period and a radio in which communication is not set in the reception period among the plurality of radios, 6. The radio base station apparatus according to claim 2, wherein a transmission antenna for each radio device is selected from the plurality of antennas and assigned. 8. The plurality of radios, wherein the received signal quality value is equal to or less than a predetermined value for all of the plurality of antennas during the reception period, or the data error rate is equal to all of the plurality of antennas. The low signal quality radio which has become a predetermined value or more with respect to the antenna, and excluding the reception signal quality value or the data error rate in the low signal quality radio, the transmitting antenna for each radio, the plurality of Claim 2, wherein the antenna is selected and assigned.
The radio base station apparatus according to claim 3, 4, or 5.