JP2003023379A - Transmitting diversity method and antenna switching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmitting diversity method and an antenna switching device, with which a transmitting diversity effect can be provided without deteriorating the demodulation performance of a mobile station using a single user type BLE. SOLUTION: This device is provided with a received power measuring instrument 3 for measuring a received power for each of users #1-#K, a transmitting antenna selector 10 for selecting a transmitting antenna from the received power measured by the received power measuring instrument 3, a signal multiplexer 11 for multiplexing user signals from the users #1-#K and a transmitting antenna switcher 12 for switching transmitting/receiving antennas 1-1, 1-2,..., 1-n according to the selected result of the transmitting antenna selector 10. Then, the received power of a received time slot is measured for each user and each antenna, the antenna of the greatest received power is selected for each user to transmit data by the present transmitting slot, and the antenna to be selected by the largest number of users is selected as a transmitting antenna.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission diversity method and an antenna switching device suitable for use in a base station device of a mobile radio communication system.

[0002]

2. Description of the Related Art FIG. 15 is a block diagram showing a configuration of a conventional antenna switching device. In this figure, each transmission / reception antenna 1-1, 1-2, ..., 1-n is provided with a transmission / reception switch 2, which is switched to the reception side during reception and switched to the transmission side during transmission. The received signals are input to the received power measuring devices 3 prepared for the number of users (# 1 to #K).

Each received power measuring device 3 measures the received power for each user and inputs the measured power to the transmitting antenna selector 4. The transmission antenna selector 4 selects the antenna that has the maximum value among the reception powers measured by the reception power measuring device 3 for each user, and inputs the result to the transmission antenna switcher 5. The transmission antenna switching device 5 switches the antenna for each user. The user # 1 signal to the user #K signal, which are user signals, are multiplexed by the multiplexer 6 prepared for each antenna and then output to the antenna selected by the transmission antenna selector 4.

FIG. 16 is a flow chart showing the operation of this conventional antenna switching device. The reception power is measured for each antenna in the reception slots of the plurality of users (step 130). Next, the antenna with the highest received power is selected as the transmission antenna for each user (step 132). Then, the antenna is switched to the selected antenna (step 134). After the above processing is performed for all users (step 136), the antenna is switched to the antenna selected for each user, and the user signal is multiplexed and transmitted to each antenna (step 138).

As described above, in TDD (Time Division Duplex) communication in which the same frequency is used in the upper and lower lines, the propagation attenuation amount is substantially the same in the upper and lower lines, so that a signal is always transmitted from an antenna with a good propagation path condition. It becomes possible to do. As is well known, in the TDD system, there are uplink time slots and downlink time slots.
FIG. 17 shows an example thereof. The radio frame is divided into a plurality of time slots, and each time slot is assigned to uplink or downlink communication. In the base station, an uplink time slot means a reception time slot, and a downlink time slot means a transmission time slot.

[0006]

However, in the conventional antenna switching device, the single-user type BL is used.
A mobile station using an E (Block Linear Equalizer) has a problem that demodulation performance deteriorates. As one of single-user BLE, "Data detection algorithms specially des
igned for the downlink of CDMA mobile radio system
s ", Klein, A., Vehicular Technology Conference, 1
997, IEEE 47th, Volume: 1, 1997, Page (s): 203-2
Some are listed in 07.

When a single-user BLE is used on the mobile station side, demodulation is performed on the assumption that the transmission signal from the base station reaches the mobile station through one propagation path. If there are signals that arrive through different propagation paths, demodulation performance will deteriorate.

The present invention has been made in view of the above points, and a transmission diversity method and an antenna capable of obtaining a transmission diversity effect without degrading the demodulation performance of a mobile station using a single-user BLE. An object is to provide a switching device.

[0009]

A transmission diversity method of the present invention is a transmission diversity method for performing transmission diversity using a plurality of transmission / reception antennas in a base station, and the reception power in a reception slot of each user is Measurement is performed for each antenna, a transmission antenna common to all transmission users is selected by using a part or all of the measured reception power of each user, and all user signals are transmitted from the selected transmission antenna.

According to this method, since the signals of all users are transmitted from the base station with one antenna, the signals reach the mobile station through one propagation path. Therefore, single-user type BLE is used. It becomes possible to perform transmission diversity without degrading the demodulation performance of the existing mobile station.

Further, the transmission diversity method of the present invention is
In the transmission diversity method, the received power of a user who intends to transmit in the current transmission slot is compared between antennas, and the antenna with the largest received power is selected as the transmit antenna.

According to this method, it is possible to maximize the number of users who can obtain the effect of transmission diversity.

Further, the transmission diversity method of the present invention is
In the above-mentioned transmission diversity method, the total received power of all users who intend to perform transmission in the current transmission slot is obtained for each antenna, and the antenna with the maximum total received power is selected as the transmit antenna.

According to this method, it is possible to maximize the transmission diversity effect of combining all user signals.

Further, the transmission diversity method of the present invention is
In the above transmission diversity method, the user having the highest transmission power is selected among the users who intend to perform transmission in the current transmission slot, and the antenna having the maximum reception power in the previous reception slot of the selected user is selected as the transmission antenna. To do.

According to this method, it is possible to increase the transmission diversity effect of the user having the highest transmission power.

Further, the transmission diversity method of the present invention is
In the above transmission diversity method, the user having the highest downlink transmission rate is selected from among the users who intend to perform transmission in the current transmission slot, and the antenna having the maximum reception power in the previous reception slot of the selected user is transmitted. Select as an antenna.

According to this method, the user who is transmitting at the highest speed can maximize the transmission diversity effect, so that it is possible to maintain the reception quality of the high-speed transmitting user.

The transmission diversity method of the present invention is
In the above-mentioned transmission diversity method, among the users who are going to perform transmission in the current transmission slot, the variation amount of the reception power of the previous reception slot or the average value of the variation amount for a certain period of time is selected, and the selected user is selected. The antenna with the maximum received power in the previous reception slot of is selected as the transmission antenna.

According to this method, the user having a small variation in the received power, that is, the user moving at a low speed where the transmission diversity effect is easily obtained is prioritized, so that the transmission diversity effect can be efficiently obtained.

Further, the transmission diversity method of the present invention is
In the above-mentioned transmission diversity method, among the users who are going to perform transmission in the current transmission slot, the user who selects the minimum variation in the received power difference between the antennas in the previous reception slot or the average of the variation over a certain period is selected. , The antenna having the maximum received power in the previous reception slot of the selected user is selected as the transmission antenna.

According to this method, the user having a small variation in the received power difference between the antennas, that is, the user moving at a low speed that is likely to obtain the transmission diversity effect is prioritized, so that the transmission diversity effect can be efficiently obtained. Becomes

The antenna switching device of the present invention uses a plurality of transmission / reception antennas, reception power measuring means for measuring the reception power of each user, and transmission using the reception power of the user who intends to transmit in the current transmission slot. It is configured to include a transmitting antenna selecting unit that selects a trusted antenna and an antenna switching unit that switches to an antenna that transmits all user signals in the current slot according to the selection result of the transmitting antenna selecting unit.

According to this configuration, since signals of all users are transmitted from the base station with one antenna, the signals reach the mobile station through one propagation path. Therefore, single-user type BLE is used. It becomes possible to perform transmission diversity without degrading the demodulation performance of the existing mobile station.

Further, the antenna switching device of the present invention is the above antenna switching device, wherein the transmitting antenna selection means is
The received power of the user who intends to transmit in the current transmission slot is compared between the antennas, and the antenna with the largest number of users having the highest received power is selected as the transmission antenna.

According to this structure, the antenna selected by the largest number of users is selected as the transmission antenna, so that it is possible to maximize the number of users who can maximize the effect of transmission diversity.

Further, the antenna switching device of the present invention is the above antenna switching device, wherein the transmitting antenna selection means is
The total received power of all users who intend to perform transmission in the current transmission slot is calculated for each antenna, and the antenna with the maximum total received power is selected.

According to this structure, it is possible to maximize the transmission diversity effect of combining all user signals.

Further, in the antenna switching device of the present invention, in the above antenna switching device, the transmitting antenna selection means is
Among the users trying to transmit in the current transmission slot, the antenna having the highest reception power in the previous reception slot of the user having the highest transmission power is selected.

According to this configuration, the user with the highest transmission power can maximize the transmission diversity effect,
When the transmission power control is used, it is possible to reduce the transmission power in the next slot and thereafter.

The antenna switching device of the present invention is the above antenna switching device, wherein the transmitting antenna selection means is
An antenna having the highest received power in the previous reception slot of the user having the highest downlink transmission rate among the users who intend to perform transmission in the current transmission slot is selected.

According to this structure, the user who is transmitting at the highest speed can obtain the transmission diversity effect to the maximum extent, so that it is possible to maintain the reception quality of the high-speed transmitting user.

Further, the antenna switching device of the present invention is the above antenna switching device, wherein the transmitting antenna selection means is
Among the users who are going to transmit in the current transmission slot, the antenna having the maximum received power in the previous reception slot in the user having the smallest variation in the received power in the previous reception slot or the average value of the received variation over a certain period Select.

According to this structure, it is possible to efficiently obtain the transmission diversity effect by giving priority to a user having a small variation in the received power, that is, a user who is moving at a low speed where the transmission diversity effect is easily obtained.

Further, the antenna switching device of the present invention is the above antenna switching device, wherein the transmitting antenna selection means is
Among the users attempting to transmit in the current transmission slot, the variation in the difference in reception power between the antennas in the previous reception slot or the average value of the variation over a certain period of time is the minimum in the reception power of the user in the previous reception slot. Select the antenna.

According to this structure, the transmission diversity effect can be efficiently obtained by giving priority to the user having a small variation in the received power difference between the antennas, that is, the user moving at a low speed which is likely to obtain the transmission diversity effect. It will be possible.

The base station apparatus of the present invention has a configuration including the above antenna switching apparatus.

According to this structure, a single-user type B
Without degrading the demodulation performance of the mobile station using LE,
It becomes possible to perform transmission diversity.

The mobile radio communication system of the present invention has a configuration including the above base station apparatus and a communication terminal apparatus for performing radio communication via the base station apparatus.

According to this configuration, the base station apparatus can perform transmission diversity without degrading the demodulation performance of the mobile station using the single-user type BLE.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION The essence of the present invention is to measure the reception power of a reception slot for each user for each antenna and select a transmission antenna common to all transmission users by using a part or all of the measured reception power. , Transmitting all user signals from the selected transmitting antenna.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of an antenna switching apparatus according to Embodiment 1 of the present invention. In this figure, the same parts as those in FIG. 15 described above are designated by the same reference numerals. Further, the antenna switching device of the present embodiment is used for a base station device of a mobile radio communication system of TDD communication system.

In FIG. 1, the antenna switching apparatus according to the present embodiment has a plurality of transmitting / receiving antennas 1-1, 1-2, ...
1-n and each transmitting / receiving antenna 1-1, 1-2, ..., 1-
A transmission / reception switch 2 for switching n between transmission and reception, a reception power measuring device 3 for measuring reception power for each user (# 1 to #K), and a transmission antenna from reception power measured by the reception power measuring device 3. The transmitting antenna selector 10 to be selected, the signal multiplexer 11 that multiplexes the transmitting signals (that is, user signals) from the users # 1 to #K, and the transmitting / receiving antennas 1-1, 1- according to the selection result of the transmitting antenna selector 10. 2, ..., 1-
and a transmitting antenna switch 12 for switching n.

Each transmitting / receiving antenna 1 in the receiving time slot
The signals received at -1, 1-2, ..., 1-n are input to the received power measuring device 3. There are as many reception power measuring devices 3 as there are users, and the transmission / reception antennas 1-1 and 1 are provided for each user.
The received power at -2, ..., 1-n is measured. The reception power measured by each reception power measuring device 3 is input to the transmission antenna selector 10. The transmission antenna selector 10 selects one transmission antenna using the reception power of each antenna of each user. In this selection, the received signal of the user transmitting in the target transmission time slot is used.

The selection result from the transmission antenna selector 10 is input to the transmission antenna selector 12. The transmission antenna switching unit 12 switches the transmission / reception antennas 1-1, 1-2, ..., 1-n according to the selection result from the transmission antenna selector 10. In the transmission timeslot, the signal multiplexer 1
In 1, the user signals of users # 1 to #K are multiplexed and output to the transmission / reception antennas set in the transmission antenna switching unit 12.

The operation of the antenna switching device having the above configuration is shown in a flowchart of FIG. First, the reception power of each user is measured for each antenna in the reception time slot (steps 10 and 12). Then, in the transmission time slot, one antenna for which the effect of the transmission diversity becomes large is selected by using the reception power of each antenna of all users transmitting in the time slot (step 14).
Then, the antenna is switched to the selected antenna, and user signals for all users are transmitted from the antenna (step 1
6, 18).

When there are a plurality of reception time slots used by one user in one frame, it is preferable to use the reception power of the past reception time slot closest to the transmission time slot.

As described above, according to the antenna switching apparatus of the present embodiment, the user signals of all users are transmitted from one antenna, so that the single-user BL is used.
It becomes possible to perform transmission diversity without degrading the demodulation performance of the mobile station using E. Further, the conventional antenna switching device requires the multiplexer 7 (see FIG. 15) for multiplexing each user signal for each antenna, but in the present invention, only one multiplexer (signal multiplexer 11) is required. The device can be simplified and the cost can be reduced.

(Second Embodiment) FIG. 3 is a block diagram showing the configuration of the main part of an antenna switching apparatus according to the second embodiment of the present invention. The antenna switching device of the present embodiment is
Transmitting antenna selector 10 of the antenna switching device shown in FIG.
Other than that, the configuration is the same, and the portion corresponding to the transmission antenna selector 10 is composed of a maximum power antenna detector 13 and a detection number comparator 14, as shown in FIG.
Note that the base station apparatus having the antenna switching apparatus of this embodiment also performs TDD communication. As described above, the TDD method has a transmission time slot and a reception time slot.

Signals received by the transmitting / receiving antennas 1-1, 1-2, ..., 1-n in the receiving time slot in the base station apparatus are input to the received power measuring device 3. There are as many received power measuring devices 3 as there are users, and the received power of all antennas is measured for each user. The received power measured by the received power measuring device 3 is input to the maximum power antenna detector 13. The maximum power antenna detector 13 detects one antenna having the maximum received power for each user. In this detection, the received signal of the user transmitting in the target transmission time slot is used. Maximum power antenna detector 1
The antenna number detected in 3 is input to the detection number comparator 14.

The number-of-detections comparator 14 compares the numbers detected for each antenna and selects one antenna having the largest number of detections. That is, one antenna selected by the most users is selected. The selection result is input to the transmission antenna switching unit 12. The transmission antenna switching unit 12 switches the transmission antenna according to the selection result from the detection number comparator 14. In the transmission time slot, the user signals for all users are multiplexed in the signal multiplexer 11, and the multiplexed user signals are output to the antenna set in the transmission antenna switcher 12.

The operation of the antenna switching device having the above configuration is shown in a flowchart of FIG.

First, the reception power of each user is measured for each antenna in the reception time slot (steps 20, 2).
2). Then, in the transmission time slot, the antenna with the highest received power is selected for each user transmitting in that time slot (steps 24 and 26). Then, the antenna selected by the most users is selected as the transmission antenna (step 28). Then, the selected antenna is switched to and user signals for all users are transmitted (steps 30 and 32). At this time, if an antenna having a large received power for each user is selected, the received power of the downlink will also become large. That is, a transmission diversity effect can be expected.

When there are a plurality of reception time slots used by one user in one frame, it is preferable to use the reception power of the past reception time slot closest to the transmission time slot.

As described above, according to the antenna switching apparatus of the present embodiment, in addition to the same effect as the antenna switching apparatus of the first embodiment, the number of users who can maximize the effect of transmission diversity is maximized. It becomes possible.

(Embodiment 3) FIG. 5 is a block diagram showing the configuration of a main part of an antenna switching apparatus according to Embodiment 3 of the present invention. The antenna switching device of the present embodiment is
Transmitting antenna selector 10 of the antenna switching device shown in FIG.
Other than that, the configuration is the same, and the portion corresponding to the transmission antenna selector 10 is configured by a per-antenna power adder 15 and a received power comparator 16, as shown in FIG.
Note that the base station apparatus having the antenna switching apparatus of this embodiment also performs TDD communication.

In the base station device, the signal received from each antenna in the reception time slot is input to the reception power measuring device 3. The reception power measuring devices 3 exist for the number of users and measure the reception power of all antennas for each user. The received power measured by the received power measuring device 3 is input to the per-antenna power adder 15, and the received signals of all users are added. At this time, the received signal of the user transmitting in the target transmission time slot is used. The addition result from the power adder for each antenna 15 is input to the reception power comparator 16.

The reception power comparator 16 compares the addition results for each antenna and selects the largest antenna. The selection result is input to the transmission antenna switching unit 12. The transmission antenna switching unit 12 switches the transmission antenna according to the selection result from the reception power comparator 16. In the transmission time slot, user signals for all users are multiplexed in the signal multiplexer 11 and output to the antenna set in the transmission antenna switcher 12.

The operation of the antenna switching device having the above configuration is shown in a flowchart of FIG. First, the reception power of each user is measured for each antenna in the reception time slot (steps 30 and 32). Then, in the transmission time slot, the total received power of all the users transmitting in the transmission slot is calculated for each antenna (step 3).
4, 36). Then, the antenna with the maximum total received power is selected as the transmitting antenna (step 3).
8). Next, after switching the transmission antenna to the selected antenna, user signals for all users are transmitted (steps 40 and 42).

The fact that the received power is large means that the state of the propagation path is good or that the number of used resources such as spreading codes is large. By transmitting from the antenna with the large total received power, the total of all user signals is increased. The transmit diversity effect is best obtained.

As described above, according to the antenna switching device of the present embodiment, in addition to the same effects as those of the antenna switching device of the first embodiment, it is possible to enhance the total transmission diversity effect of all user signals. .

(Embodiment 4) FIG. 7 is a block diagram showing the configuration of the main part of an antenna switching apparatus according to Embodiment 4 of the present invention. The antenna switching device of the present embodiment is
Transmitting antenna selector 10 of the antenna switching device shown in FIG.
Other than that, the configuration corresponding to the transmission antenna selector 10 is the same as that shown in FIG.
And a reception power comparator 18 and a transmission power comparator 19. Note that the base station apparatus having the antenna switching apparatus of this embodiment also performs TDD communication.

In the base station device, the signal received from each antenna in the reception time slot is input to the reception power measuring device 3. The reception power measuring devices 3 exist for the number of users and measure the reception power of all antennas for each user. In the transmission slot, the user signal is input to the transmission power comparator 19, and the power of each user is measured and compared. Then, one user having the highest transmission power is selected, and the result is input to the user switching device 17.

The user switching unit 17 includes a transmission power comparator 19
The user to be input to the reception power comparator 18 is switched according to the selection result from. That is, the reception signal of the selected user is input to the reception power comparator 18. The reception power comparator 18 compares the reception power of each antenna and selects the antenna having the maximum reception power. Then, the selection result is input to the transmission antenna switching unit 12.

The transmission antenna switching unit 12 switches the transmission antenna according to the selection result from the reception power comparator 18. In the transmission time slot, user signals for all users are multiplexed in the signal multiplexer 11 and transmitted from the antenna set in the transmission antenna switcher 12.

The operation of the antenna switching device having the above configuration is shown in a flowchart of FIG. First, the reception power of each user is measured for each antenna in the reception time slot (steps 50 and 52). Then, in the transmission time slot, the transmission power of all users transmitting in the transmission slot is measured (steps 54 and 56). Next, the user with the highest transmission power is selected (step 58).
Then, the antenna having the maximum received power of the selected user is selected as the transmission antenna (step 60).
Then, it switches to the selected antenna and transmits a user signal (steps 62 and 64).

As a result, the downlink reception state of the user with the higher priority transmission power is improved, so that the transmission power of the downlink is reduced in the next frame in the case of the system for controlling the transmission power.

As described above, according to the antenna switching apparatus of the present embodiment, in addition to the effect similar to that of the antenna switching apparatus of the first embodiment, the transmission diversity effect is enhanced by giving priority to the user having the highest transmission power. It becomes possible. Moreover, an increase in system capacity can be expected by reducing the transmission power of the user having the maximum transmission power.

(Fifth Embodiment) FIG. 9 is a block diagram showing the configuration of the main part of an antenna switching apparatus according to the fifth embodiment of the present invention. The antenna switching device of the present embodiment is
Transmitting antenna selector 10 of the antenna switching device shown in FIG.
Other than that, the configuration corresponding to the transmission antenna selector 10 is the same as that shown in FIG.
And a reception power comparator 18 and a transmission rate comparator 20. Note that the base station apparatus having the antenna switching apparatus of this embodiment also performs TDD communication.

In the base station device, the signal received from each antenna in the reception time slot is input to the reception power measuring device 3. The reception power measuring devices 3 exist for the number of users and measure the reception power of all antennas for each user. The user signal transmitted in the transmission slot is input to the transmission rate comparator 20. The transmission rate comparator 20 measures and compares the transmission rates of the respective users, selects one user having the largest transmission rate, and inputs the result to the user switching unit 17. The transmission rate comparator 20 may be directly informed of the transmission rate of each user as the control information.

The user switching unit 17 is the transmission rate comparator 2
The user inputting to the reception power comparator 18 is switched according to the selection result of 0. That is, the reception signal of the selected user is input to the reception power comparator 18. The reception power comparator 18 compares the reception power of each antenna and selects the antenna having the maximum reception power. Received power comparator 18
The selection result of is input to the transmission antenna switching unit 12. The transmission antenna switching unit 12 switches the transmission antenna according to the selection result from the reception power comparator 18. In the transmission time slot, user signals are multiplexed for all users in the signal multiplexer and output to the antenna set by the transmission antenna switching unit 12.

The operation of the antenna switching device having the above configuration is shown in a flowchart of FIG. First, the reception power of each user is measured for each antenna in the reception time slot (steps 70 and 72). Then, in the transmission time slot, the downlink transmission rates of all users transmitting in the transmission slot are observed, and the user having the highest downlink transmission rate is selected (step 74). Next, the antenna having the maximum received power of the selected user is selected as the transmitting antenna (step 76). Then, the antenna is switched to the selected antenna, and user signals for all users are transmitted from the antenna (steps 78 and 8).
0).

As described above, according to the antenna switching apparatus of the present embodiment, in addition to the same effects as those of the antenna switching apparatus of the first embodiment, the user who is transmitting at the highest speed can obtain the maximum transmission diversity effect. By doing so, it becomes possible to maintain the reception quality of high-speed transmission users. In particular, when the reception quality of high-speed transmission users deteriorates, the number of retransmissions increases, which causes a decrease in system capacity.
The antenna switching device according to the present embodiment can prevent a decrease in system capacity.

(Sixth Embodiment) FIG. 11 is a block diagram showing the configuration of the main part of an antenna switching apparatus according to the sixth embodiment of the present invention. The antenna switching device of the present embodiment has the same configuration except the transmission antenna selector 10 of the antenna switching device shown in FIG.
As shown in FIG. 11, the portion corresponding to (1) includes a user switch 17, a received power comparator 18, a received power fluctuation amount measuring device 21, and a fluctuation amount comparator 22. Note that the base station apparatus having the antenna switching apparatus of this embodiment also performs TDD communication.

In the base station device, the signal received from each antenna in the reception time slot is input to the reception power measuring device 3. The reception power measuring devices 3 exist for the number of users and measure the reception power of all antennas for each user. The reception power measured by the reception power measuring device 3 is input to the reception power fluctuation amount measuring device 21, and the fluctuation amount from the previous reception slot is measured. This variation is averaged for each antenna.

The fluctuation amount measured by each received power fluctuation amount measuring device 21 is input to the fluctuation amount comparator 22, and the user having the smallest fluctuation amount is selected. This selection result is the user switching device 17
Entered in. The user switching device 17 includes a fluctuation amount comparator 22.
The user to be input to the reception power comparator 18 is switched according to the selection result from. That is, the reception signal of the selected user is input to the reception power comparator 18. The reception power comparator 18 compares the reception power of each antenna and selects the antenna having the maximum reception power.

The selection result from the reception power comparator 18 is input to the transmission antenna switching unit 12. The transmission antenna switching unit 12 switches the transmission antenna according to the selection result from the reception power comparator 18. In the transmission time slot, user signals for all users are multiplexed by the signal multiplexer 11 and transmitted from the antenna set by the transmission antenna switching unit 12.

The operation of the antenna switching device having the above configuration is shown in a flowchart of FIG. First, the reception power of each user is measured for each antenna in the reception time slot (steps 90 and 92). Then, in the transmission time slot, the fluctuation amount of the received power from the reception slot before the previous reception slot is measured for all the users transmitting in the transmission slot, and the fluctuation amount is averaged for a certain period (step 94-). 98). Then, the user having the smallest average fluctuation amount is selected (step 100). Then, the antenna having the highest reception power in the previous reception slot of the selected user is selected, and after switching to that antenna, user signals for all users are transmitted (step 10).
2-106).

As described above, according to the antenna switching device of the present embodiment, in addition to the same effects as those of the antenna switching device of the first embodiment, a user with a small variation in received power, that is, a transmission diversity effect, can be obtained. It is possible to efficiently obtain the transmission diversity effect by giving priority to the user who is moving easily at low speed.

(Embodiment 7) FIG. 13 is a block diagram showing a configuration of a main part of an antenna switching apparatus according to Embodiment 7 of the present invention. The antenna switching device of the present embodiment has the same configuration except the transmission antenna selector 10 of the antenna switching device shown in FIG.
As shown in FIG. 13, the part corresponding to the user switching device 17, the reception power comparator 18, and the reception power difference measuring device 23 are
And a fluctuation amount measuring device 24 and a fluctuation amount comparator 22. Note that the base station apparatus having the antenna switching apparatus of this embodiment also performs TDD communication.

In the base station apparatus, the signal received from each antenna in the reception time slot is input to the reception power measuring device 3. The reception power measuring devices 3 exist for the number of users and measure the reception power of all antennas for each user. The received power measured by the received power measuring device 3 is input to the received power difference measuring device 23, and the received power difference between the antennas is measured. For example, if there are three or more antennas, the difference between the maximum power and the minimum power is measured. The received power difference measured by the received power difference measuring device 23 is input to the fluctuation amount measuring device 24, and the fluctuation amount from the previous reception slot is measured.

The fluctuation amount measured by the fluctuation amount measuring unit 24 is input to the fluctuation amount comparator 22, and the user having the smallest fluctuation amount is selected. The selection result from the fluctuation amount comparator 22 is input to the user switching device 17. The user switching unit 17 switches the user inputting to the received power comparator 18 according to the selection result from the fluctuation amount comparator 22. That is, the reception signal of the selected user is input to the reception power comparator 18.
The reception power comparator 18 compares the reception power of each antenna and selects the antenna having the maximum reception power. The selection result from the reception power comparator 18 is the transmission antenna switch 1
Entered in 2.

The transmission antenna switching unit 12 switches the transmission antenna according to the selection result from the reception power comparator 18. In the transmission time slot, user signals for all users are multiplexed in the signal multiplexer 11 and transmitted from the antenna set in the transmission antenna switcher 12.

The operation of the antenna switching device having the above configuration is shown in a flowchart of FIG. First, the reception power of each user is measured for each antenna in the reception time slot (steps 110 and 112). Then, in the transmission time slot, the variation amount of the reception power difference between the antennas of the previous reception slots of all the users transmitting in the transmission slot from the previous reception slot is measured, and the variation amount is averaged for a certain period ( Steps 114-120). Then, the user having the smallest average variation is selected (step 122). Then, the antenna having the maximum received power in the previous reception slot of the selected user is selected as the transmission antenna (step 124). Then, the transmission antenna is switched to the selected antenna and user signals for all users are transmitted (steps 126 and 128).

As described above, according to the antenna switching device of the present embodiment, in addition to the same effects as the antenna switching device of the first embodiment, the user, that is, the transmission diversity, in which the variation amount of the received power difference between the antennas is small. By giving priority to a user who is moving slowly and is likely to obtain an effect, it is possible to efficiently obtain the transmission diversity effect.

[0087]

As described above, according to the present invention,
It is possible to provide a transmission diversity method and an antenna switching device that can obtain a transmission diversity effect without degrading the demodulation performance of a mobile station using single-user BLE.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an antenna switching device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the antenna switching device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a main part of an antenna switching device according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of the antenna switching device according to the second embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a main part of an antenna switching device according to a third embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the antenna switching device according to the third embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a main part of an antenna switching device according to a fourth embodiment of the present invention.

FIG. 8 is a flowchart showing an operation of the antenna switching device according to the fourth embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a main part of an antenna switching device according to a fifth embodiment of the present invention.

FIG. 10 is a flowchart showing the operation of the antenna switching device according to the fifth embodiment of the present invention.

FIG. 11 is a block diagram showing a configuration of a main part of an antenna switching device according to a sixth embodiment of the present invention.

FIG. 12 is a flowchart showing an operation of the antenna switching device according to the sixth embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a main part of an antenna switching device according to a seventh embodiment of the present invention.

FIG. 14 is a flowchart showing the operation of the antenna switching device according to the seventh embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a conventional antenna switching device.

FIG. 16 is a flowchart showing the operation of the conventional antenna switching device.

FIG. 17 is a diagram showing an example of how to use a time slot in the TDD system.

[Explanation of symbols]

1-1, 1-2, ..., 1-n Transmission / reception antenna 2 send / receive switch 3 Received power measuring instrument 10 Transmit antenna selector 11 Signal multiplexer 12 Transmit antenna switch 13 Maximum power antenna detector 14 Detection number comparator 15 Antenna power adder 16 Received power comparator 17 User switch 18 Received power comparator 19 Transmit power comparator 20 Transmission rate comparator 21 Received power fluctuation measuring instrument 22 Fluctuation comparator 23 Received power difference measuring instrument 24 Fluctuation meter

Claims (16)

[Claims] 1. A transmission diversity method for performing transmission diversity in a base station using a plurality of transmission / reception antennas, wherein the reception power in a reception slot of each user is measured for each user, and the measured reception of each user is performed. A transmission diversity method characterized in that a transmission antenna common to all transmission users is selected by using a part or all of electric power and all user signals are transmitted from the selected transmission antenna. 2. The reception power of a user who intends to transmit in the current transmission slot is compared between antennas, and the antenna having the largest reception power is selected as the transmission antenna. The transmission diversity method according to claim 1. 3. The total of the reception power of all users who intend to perform transmission in the current transmission slot is calculated for each antenna, and the antenna having the maximum total reception power is selected as the transmission antenna. 1. The transmission diversity method described in 1. 4. The user having the highest transmission power is selected from the users who intend to perform transmission in the current transmission slot, and the antenna having the highest reception power in the previous reception slot of the selected user is selected as the transmission antenna. The transmission diversity method according to claim 1, wherein: 5. The transmitting antenna is selected by selecting the user having the highest downlink transmission rate among the users who intend to perform transmission in the current transmission slot and selecting the antenna having the maximum reception power in the previous reception slot of the selected user. The transmission diversity method according to claim 1, wherein the transmission diversity method is selected as 6. A user having a minimum variation in received power of a previous reception slot or an average value of the variation over a fixed period is selected from among users who intend to perform transmission in the current transmission slot,
2. The transmit diversity method according to claim 1, wherein an antenna having the maximum received power in the previous reception slot of the selected user is selected as a transmission antenna. 7. Among the users who are going to perform transmission in the current transmission slot, a user having the smallest variation amount of the received power difference between the antennas of the previous reception slot or the average value of the variation amount for a certain period is selected, 2. The transmit diversity method according to claim 1, wherein an antenna having a maximum reception power of the previous reception slot of the selected user is selected as a transmission antenna. 8. A transmission antenna is selected using a plurality of transmission / reception antennas, reception power measuring means for measuring reception power for each user, and the reception power of a user who intends to perform transmission in the current transmission slot. Transmitting antenna selection means,
An antenna switching device for switching to an antenna for transmitting all user signals of the current slot according to the selection result of the transmission antenna selection unit. 9. The transmission antenna selection means compares the reception power of a user who intends to perform transmission in the current transmission slot between the antennas, and selects the antenna having the largest reception power as the transmission antenna. 9. The antenna switching device according to claim 8, wherein: 10. The transmitting antenna selecting means obtains the total received power of all users who intend to perform transmission in the current transmission slot for each antenna, and selects the antenna having the maximum total received power. The antenna switching device according to claim 8. 11. The transmitting antenna selecting means selects an antenna having the maximum received power in the previous reception slot of the user having the largest transmission power among the users who intend to perform transmission in the current transmission slot. The antenna switching device according to claim 8. 12. The transmitting antenna selecting means selects an antenna having the highest received power in the previous receiving slot of the user having the highest downlink transmission rate among the users who intend to perform transmission in the current transmitting slot. Claim 8 characterized by
The antenna switching device described. 13. The transmitting antenna selection means is a user who has the smallest fluctuation amount of the reception power in the previous reception slot or the average value of the reception fluctuation amount in a certain period among the users who are going to transmit in the current transmission slot. 9. The antenna switching device according to claim 8, wherein the antenna having the highest received power in the previous reception slot in is selected. 14. The transmission antenna selection means minimizes a variation amount of a received power difference between antennas of a previous reception slot or an average value of the variation amount for a certain period of time among users trying to perform transmission in the current transmission slot. 9. The antenna switching device according to claim 8, wherein the antenna having the maximum reception power of the previous reception slot for the user is selected. 15. A base station device comprising the antenna switching device according to claim 8. 16. A mobile radio communication system comprising: the base station apparatus according to claim 15; and a communication terminal apparatus that performs radio communication via the base station apparatus.