JP3240984B2 - FDD / CDMA transmitting / receiving system, CDMA receiving apparatus, and CDMA transmitting apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CDMA transmission / reception system, and more particularly to a CDM generally applied to a downlink (communication from a base station to a mobile station) of a mobile communication system.
A (Code Division Multiple)
Access).

[0002]

2. Description of the Related Art In general, a code division multiple access (CDMA) system using direct spreading has attracted attention as a multiple access system in a future mobile communication system and the like because there is a possibility that a subscriber capacity can be greatly expanded. CDMA
In a system using the system, each user multiplies the own station signal by a unique spreading code, spreads the signal over a wide frequency band, and then transmits the signal to a transmission path. On the receiving side, a desired local station signal is detected through a process of despreading from the code-multiplexed signal.

FIGS. 11A and 11B show a conventional CDMA system.
FIG. 11 is a block diagram illustrating an example of a transmission / reception system.
FIG. 11A shows a transmitting device, and FIG. 11B shows a receiving device. In this transmission / reception system, each user signal to the receiving device, that is, the mobile station is multiplexed together in the transmitting device. The pilot signal is multiplexed together with the user signal in the transmitting apparatus so that the receiving apparatus can easily estimate the reception timing and the transmission path parameter of each user signal.

Referring to FIG. 11A, in a transmitting apparatus, user signal encoders 501-1 to 501-K (K is an integer of 1 or more, the same applies hereinafter) assign each user signal uniquely to each user. Is spread with the given code. Pilot encoder 50
2 spreads the pilot signal with a unique code. The combiner 503 encodes each user signal encoder 501-1.
The user signal supplied from 〜501K and the pilot code from pilot encoder 502 are multiplexed. The transmitting antenna 504 sends out the output of the combiner 503.

Referring to FIG. 11 (b), in a receiving apparatus, pilot correlator 601 detects a pilot signal from the above-mentioned signal from transmitting antenna 504 from a received signal received by a receiving antenna (not shown), and detects a user signal. The reception timing and transmission path parameters are extracted. Similarly, the user signal correlator 602 detects a desired own station signal from the received signal. The detector 603 detects the user signal using the transmission path parameters extracted from the pilot signal. A desired demodulated signal is obtained as an output of the detector 603. Note that, in FIGS. 11A and 11B, the modem is omitted.

[0006] In a mobile communication environment, fading generally occurring on a transmission path causes deterioration of reception quality. Means for improving the reception quality in a fading environment include, for example, Japanese Patent Application No. 6-189, filed by the applicant of the present invention.
The antenna diversity system described in the specification of Japanese Patent No. 293 (name of the invention, "code division multiplex receiver") is effective. This is because, in the receiving device, a plurality of antennas are arranged so that the spatial correlation characteristics between the antennas are independent, and a selection method of selecting a signal having good quality among the signals received by the plurality of antennas, or combining by performing appropriate weighting is performed. This is a synthesis method. By applying such a method, reception characteristics in a fading environment can be improved. However, application in mobile stations is difficult due to the complexity of the device.

On the other hand, in a CDMA transmitting / receiving system as shown in FIGS. 11 (a) and 11 (b), when a desired signal is detected, interference occurs due to the cross-correlation between the own code and the other code. appear. Various interference canceling methods have been proposed to eliminate such interference with a receiver to achieve high quality (for example, Japanese Patent Application Laid-Open No. 7-030519). Information is not enough, and it is not easy from the viewpoint of the scale of the apparatus. Therefore, it is desirable to have a means for obtaining an interference reduction effect without applying an interference canceller to the mobile station.

In response to such a demand, a system has recently been proposed in which a diversity effect and an interference reduction effect can be obtained without using a plurality of antennas or interference cancellers in a mobile station. As a well-known document, "Proposal of base station transmission diversity system in CDMA / TDD transmission" by Miya, Hayashi, Kato, and Honma (IEICE Technical Report, Radio Communication Systems Research Group RCS94-73, September 1994) There is. This method is based on TDD (Time Division).
n Duplex), that is, a method in which the same radio frequency is time-divided into transmission and reception for communication, and uses the same transmission path for transmission and reception. In the uplink, the base station performs antenna diversity and performs downlink transmission from the antenna having the most effective reception characteristics. As a result, a diversity effect can be obtained in the mobile station without using a plurality of antennas.

In the CDMA system, an interference suppression effect can be expected by using such a transmission diversity system. This is because the desired signal is always sent from the best transmission path, whereas the signal to other users, that is, interference, is not always sent on the best transmission path for the user of the own station. Therefore, interference power can be reduced as compared with the case where all user signals are transmitted by a single antenna as shown in FIG.

[0010]

As described above,
In the conventional CDMA transmission / reception system shown in FIG. 11, the mobile station becomes complicated when the anti-fading and anti-interference characteristics are to be improved. In addition, although the method of performing transmission diversity using the TDD scheme has an excellent advantage,
The method requires time synchronization between transmission and reception between base stations, and the system becomes complicated.

[0011] An FDD (Frequency Division) system that is simpler than such a TDD system.
Although there is a Duplex method, that is, a method using different radio frequencies for transmission and reception, it is desirable if there is a means that can obtain the above-mentioned effects in the FDD method. Therefore, an object of the present invention is to provide an FDD / CDMA transmission / reception system that can realize transmission diversity in the FDD / CDMA system and can improve the anti-fading and anti-interference characteristics as compared with the related art.

[0012]

A CDMA transmitting / receiving system according to the present invention comprises a CDMA transmitting device and a CDMA receiving device, wherein the CDMA transmitting device includes a plurality of transmitting antennas.
And transmit different weighted transmit signals to each transmit antenna.
Output signal transmitting means and different codes for each transmitting antenna
A pilot signal spread on the transmitting antennas corresponding in
Transmitting means for transmitting a pilot signal, wherein the CDMA receiving apparatus receives signals from a plurality of transmitting antennas of the CDMA transmitting apparatus.
Receiving means for obtaining a transmission signal, from the received signal of the receiving means
Each pilot signal is detected, and each detected pilot signal is detected.
And a means for transmitting an antenna selection signal corresponding to the received power value of the signal to the CDMA transmitting apparatus. This
In the case of, the transmission signal transmitted from the signal
Weight so that the signal is transmitted to only one of the
It is attached. Also, the CDMA reception according to the present invention is performed.
The transmitting device receives signals from a plurality of transmitting antennas of the CDMA transmitting device.
Multiple pie spreads with different codes for each transmit antenna
Means for receiving the lot signal and pyro from the received signal
Signal, and the received power of each detected pilot signal
Means for generating an antenna selection signal according to the force value;
Transmitting the selected antenna selection signal to the CDMA transmitting apparatus
And means for performing the above. In addition,
A CDMA transmitter according to Ming comprises a plurality of transmit antennas,
Each transmit antenna has a different weight based on the antenna selection signal.
Signal transmission means for transmitting the transmission signals
Multiple pilot signals spread with different codes for each antenna
Signal transmission to transmit to each corresponding transmitting antenna
Communication means and the CDMA receiver detects from the received signal.
Generated in accordance with the received power value of each pilot signal
Means for receiving an antenna selection signal.
It is.

Therefore, the CDMA transmitting apparatus weights and transmits transmission signals from a plurality of antennas. Further, a pilot signal for specifying the antenna is transmitted in the receiving device separately from each transmission signal. The CDMA receiving apparatus receives the pilot signal and transmits antenna selection signals for a plurality of antennas to the transmitting apparatus according to the received pilot signal.

[0014]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of one embodiment of a CDMA transmitting apparatus TR in a CDMA transmitting / receiving system according to the present invention, and FIG. 2 is a CDMA transmitting apparatus according to the present invention.
It is a block diagram showing composition of one embodiment of CDMA receiver RV in a transmitting and receiving system.

Referring to FIG. 1, in transmitting apparatus TR, user signal encoders 101-1 to 101-K are configured to assign user signals 10-1 to 10-K of K stations to codes uniquely assigned to each user. Spread with. The antenna selection / weighting circuits 103-1 to 103-K use the antenna selection signals obtained for each user or the weighting signals to set the transmission antennas for each user to N antennas 107-1 to 107-107.
-N, or weighted and transmitted to antennas 107-1 to 107-N.

FIG. 3 is a diagram showing a configuration of the antenna selection / weighting circuit 103. As shown in FIG. FIG. 3A shows an example of an antenna selection method using an antenna selection signal, and FIG. 3B shows a weighting circuit 103-i (i = 1−1).
K) shows one example. In the case of the antenna selection method of FIG. 3A, the selection circuit 103A determines to which combiner the signal from each signal encoder should be output based on the antenna selection signal.

In the case of the weighting method shown in FIG. 3B, the signals from the respective signal encoders are calculated based on the antenna weighting signals by the respective arithmetic units 103a, 103a in the weighting circuit 103B.
, 103n are given weights 1, 2,..., N, and the results are combined with the combiners 105-1, 105-2,.
.. Transmitted to 105N. Note that the antenna selection scheme is a modification of the weighting scheme, and can be considered to be weighted so that the signal from each signal encoder is transmitted to only one combiner (antenna). In other words, a signal of weight "1" is transmitted to only one combiner, and a signal of weight "0" is transmitted to a combiner (transmitting antenna) from which all other outputs are not transmitted. Think.

In the case of the combining system, a large weight is applied to a user signal to an antenna on a good transmission path, and a small weight is applied to a user signal to an antenna on a bad transmission path. Referring again to FIG. 1, pilot encoders 104-1 to 104-N (N is an integer of 2 or more, the same applies hereinafter) are used for pilot signals 40-1 to 107-N of transmission antennas 107-1 to 107-N. 40-N is spread with a code uniquely assigned. The combiners 105-1 to 105-N add the outputs of the antenna selection / weighting circuits 103-1 to 103-K and the outputs of the pilot encoders 104-1 to 104-N. The delay units 106-1 to 106-N are connected to the synthesizer 1
05-1 to 105-N are delayed, and transmission timings from the antennas 107-1 to 107-N are different from each other. The reason for this is that in the receiving device RV,
This is because the user signals transmitted from the antennas 107-1 to 107-N are temporally separated so that the antenna from which the signal has been transmitted can be easily determined. Delay device 106-1
The delay amount of the antennas 107-1 to 107-N
-N the mutual timing is greater than the delay dispersion of the transmission line,
In addition, it is desirable to set the time shorter than one symbol period of the user signal to about several chip periods. Transmission antennas 107-1 to 107-N are provided with delay units 106-1 to
Transmit the output of 106-N.

Referring to FIG. 2, in receiving apparatus RV, pilot correlators 201-1 to 201-N detect pilot signals corresponding to a transmitting antenna from received signals obtained from one receiving antenna 200, and The reception timing and transmission path parameters corresponding to the radio wave from the transmission antenna are extracted. The user signal correlator 202 detects a desired user signal from a received signal obtained from one receiving antenna 200 at each reception timing. Here, the user signal is temporally separated according to the transmission timing of the transmitted transmission antenna.

Here, a problem particularly in the selection method is that the receiving apparatus RV cannot know exactly from which transmitting antenna the user signal is transmitted. Although the antenna selection signal is detected by the receiving device RV, if an error occurs in the information when the information is transmitted through another line, the user signal may not be transmitted from the antenna considered by the receiving device.

Therefore, it is necessary for the receiving apparatus RV to independently estimate the transmitting antenna to which the user signal has been transmitted. In this example, the user signal is detected corresponding to all the transmitting antennas which may have been transmitted, and It is assumed that a demodulated signal of the transmitting antenna which is most likely to be sent is used. Detector 203
-1 to 203-N are pilot correlators 201-1 to 201-2.
The user signal is detected at the reception timing corresponding to each transmission antenna using the transmission path parameter which is the output of 01-N, and N outputs are obtained. User signal selection / synthesis circuit 20
4 is the output of the user signal correlator 202 or the detector 2
The detectors 203-203 -N are output using the outputs of the detectors 203-203 -N.
A user signal is obtained by selecting the most probable output from the outputs of 1 to 203-N, or combining them.

FIG. 4 shows an example of the user signal selection / synthesis circuit 204, and FIG. 4A shows a configuration in the case of a selection method. In FIG. 4A, the signal quality detection circuit 211 receives, for example, the output of the user signal correlator 202, obtains the symbol power of the output value of the reception timing corresponding to each antenna, and integrates it for the antenna control period. Here, since no output appears at the reception timing of the radio wave from the transmitting antenna to which no signal is transmitted, the transmitting antenna can be specified by selecting the one with the maximum detected value (the maximum received power value).

Here, assuming that the quadrature signal outputs of the reception timing corresponding to the transmission antenna of the user signal correlator 202 are I _N and Q _N , respectively, the output d _N of the signal quality detection circuit 211
Is represented by d _N = Σ ( _IN ² + Q _N ² ) (1). Note that the suffix of Σ in equation (1) is the number of symbols included in the antenna control cycle. As another example, coherent detection can be performed by using the outputs of the detectors 203-1 to 203-N.

Here, assuming that the orthogonal signal outputs of the detector 203-N are I _N and Q _N , respectively, the output d _N of the signal quality detection circuit 211 is d _N = Σ (| _IN | + | Q _N |). (2) is represented by Note that the subscript of Σ in equation (2) is the number of symbols included in the antenna control cycle. Based on this output, the selection circuit 212 detects the detectors 203-1 to 203-1.
One of the outputs 203-N is selected as a user signal.

On the other hand, in the case of the combining method shown in FIG.
The detector 203 has already been weighted by the transmitting device.
A demodulated signal (user signal) is obtained by directly combining the outputs of −1 to 203-N by the combiner 212a. FIG.
Power measurement circuits 205-1 to 205-N measure the power of each output of pilot correlators 201-1 to 201-N. The antenna selection / weighting signal detection circuit 206 outputs an antenna signal from each output of the power measurement circuits 205-1 to 205-N, or the power measurement circuits 205-1 to 205-N
, And antenna weighting signals are detected from the outputs of the detectors 203-1 to 203-N. For example, in the case of the antenna selection method, the power measurement circuits 205-1 to 205-
The transmitting antenna corresponding to the pilot signal having the maximum power among the N outputs is selected.

In the case of the combining method, weights are obtained from the respective outputs of the power measuring circuits 205-1 to 205-N and are directly transmitted, or the power measuring circuits 205-1 to 205-N
And the detectors 203-1 to 203-
A method of transmitting the comparison information using the weights actually multiplied by the transmitting device TR obtained from the respective outputs of N is conceivable. The combining method has a disadvantage in that it is difficult to transmit weight information from the receiving device to the transmitting device in a form with a relatively small amount of information, and control is complicated.

Antenna selection / weighting signal detection circuit 20
6, that is, an antenna selection / weighting signal is sent to the transmission section 300 and sent to the transmission apparatus TR via the antenna 200. In this case, the receiving apparatus RV shown in FIG. 2 shows only parts related to the present invention, and parts not directly related to the present invention are omitted. Note that in this example, different radio frequencies are used for transmission and reception because the FDD scheme is used. This FD
The D method is known.

In the present embodiment, an antenna selection signal or a weighting signal used in transmitting apparatus TR is received by receiving apparatus RV
It is necessary to transmit from the receiving device RV to the transmitting device TR on a different line (uplink line) from the line for transmitting the user signal. Therefore, there is a delay from when the antenna control signal is detected by the receiving device RV to when the signal is transmitted to the transmitting device TR and the antenna control is performed. This size is generally two to three times the antenna control period. If the fading transmission path fluctuates quickly, the transmission path changes during this time, and the antenna is erroneously controlled. Since the fluctuation speed of the transmission path is proportional to the speed of the mobile station, a diversity effect and an interference reduction effect can be expected for a low-speed mobile station, but these effects cannot be expected for a high-speed mobile station. Antenna control works well in an environment where low-speed mobile stations are mainly used, such as in a premises or a microcell, but in a microcell in which the ratio of high-speed mobile stations is high, the reception quality differs depending on the mobile station. In such a case, by performing transmission power control for each mobile station, constant reception quality can be maintained at all mobile stations, and the amount of interference of the entire system can be optimized.

Another example of the CDMA transmission / reception system according to the present invention will be described with reference to FIGS. FIG. 5 is a block diagram showing the configuration of another embodiment of the CDMA transmitting apparatus in the CDMA transmitting / receiving system according to the present invention, and FIG.
FIG. 14 is a block diagram illustrating a configuration of another embodiment of the DMA receiving apparatus. In both figures, the same parts as those in FIGS. 1 and 2 are indicated by the same reference numerals.

That is, in the configuration shown in FIGS. 5 and 6,
1 except that a configuration for controlling transmission power is added.
And the configuration of FIG. Referring to FIG. 5, in transmission device TR, power control circuits 102-1 to 102-
K receives each output of the user signal encoders 101-1 to 101-K, and controls transmission power for each user signal using a power control signal obtained for each user. Power control circuit 102
Outputs of -1 to 102-K are supplied to antenna selection / weighting circuits 103-1 to 103-K.

Referring to FIG. 6, in receiving apparatus RV, power control signal detecting circuit 207 performs a user signal selection /
Upon receiving the output of the combining circuit 204, a power control signal is detected based on, for example, a measurement of a desired signal to interference power. The transmission power control used here is sufficient to control the average value of the reception level, and the response may be slower than the antenna control cycle. There are various methods for measuring a desired signal to interference power. For example, US Pat.
Carrier-to-Noise Detector
for Digital Transmission
There is a method described in Systems. The power control signal is transmitted from the receiving device RV to the transmitting device TR on a different line (uplink) from the line for transmitting the user signal.

A further embodiment of the original CDMA transmission / reception system will be described with reference to FIGS. FIG. 7 is a block diagram showing a configuration of another embodiment of the CDMA transmitting apparatus in the CDMA transmitting / receiving system according to the present invention.
FIG. 8 is a block diagram showing the configuration of another embodiment of the CDMA receiving apparatus in the CDMA transmitting / receiving system according to the present invention. In both figures, the same parts as those in FIGS. 1 to 6 are indicated by the same reference numerals.

This embodiment is a modification of the embodiment of FIGS. 5 and 6, and the essential concept is based on the embodiment of FIGS. The embodiment of FIGS. 7 and 8 has a configuration without the delay units 106-1 to 106-N in FIG.
In the receiving apparatus RV, the user signal is not temporally separated at the output of the user signal correlator 202 corresponding to the transmission antenna. Therefore, in the configurations of FIGS. 1 and 2, the outputs of the detectors 203-1 to 203-N are almost zero except for the correct ones, whereas in the configurations of FIGS. The other values are obtained by multiplying erroneous transmission path parameters instead of zero. Therefore, in the present embodiment, the signal quality detection circuit 211 shown in Expression (1) cannot identify the signal, but the method shown in Expression (2) can identify the signal.

In the embodiments shown in FIGS. 7 and 8, a pilot signal is used for detection, but another method is to insert a pilot symbol into a user signal in advance on a time axis,
If the receiver performs detection using it (as a document,
"Fading Distortion Compensation Method for 16QAM for Land Mobile Communication" by Mikabe (Transactions of the Institute of Electronics, Information and Communication Engineers, B-IIVo)
l. J72-B-II No. 1 January 1989)), and the user signal selection circuit becomes unnecessary. However, it is not desirable from the viewpoints of detection characteristics and transmission efficiency not to use a strong pilot signal even though it is transmitted. Further, in the embodiment of FIGS. 7 and 8,
As in the case of the pilot signal, a system in which a different code is used for each antenna for the user signal is naturally considered.

Another embodiment of the CDMA transmitting / receiving system of the present invention will be described with reference to FIGS. FIG. 9 shows a CD in the CDMA transmitting / receiving system according to the present invention.
FIG. 10 is a block diagram illustrating a configuration of another embodiment of the MA transmitting apparatus, and FIG. 10 is a block diagram illustrating a configuration of another embodiment of the CDMA receiving apparatus in the CDMA transmitting / receiving system according to the present invention. In this figure, the same parts as those in FIGS. 1 to 8 are indicated by the same reference numerals.

This embodiment has a configuration in which there is only one pilot encoder in the configuration of FIG. 5, and each transmission antenna transmits a pilot signal spread with the same code. Referring to FIG. 9, at the time of transmission, delay units 106-1 to 106-1
The timing is shifted by 06-N. Therefore, FIG.
Referring to 0, the receiving apparatus can identify the antenna by using one pilot correlator 201 and separating them temporally. However, it is not easy to accurately specify the reception timing corresponding to each transmission antenna in an environment where a multipath wave exists.

In short, in the system of each of the above-described embodiments, the same effect can be obtained as when the spreading code of the pilot signal is different for each antenna or when the transmission timing of the pilot signal is different for each antenna and different codes are used. With this configuration, a transmission antenna with good transmission characteristics can be specified by measuring the magnitude of the received power value of each pilot signal in the receiving device, and thereby transmission diversity can be realized.

[0038]

In the CDMA transmission / reception system described above, transmission diversity using closed loop control by the transmission device and the reception device is realized in the FDD / CDMA system, so that the mobile station does not need to use a plurality of antennas or interference cancellers. A diversity effect and an interference reduction effect can be expected. Also, by using the transmission power control for each user signal together, the transmission power to the low-speed mobile station where the diversity effect is remarkable can be reduced, and the interference to the high-speed mobile station can be reduced. As a result, the characteristics of the entire system can be optimized .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a CDMA transmitting apparatus in a CDMA transmitting / receiving system according to the present invention.

FIG. 2 is a block diagram illustrating a configuration of an embodiment of a CDMA receiving apparatus in a CDMA transmitting / receiving system according to the present invention.

FIG. 3 is a block diagram illustrating a configuration example of an antenna selection / weighting circuit.

FIG. 4 is a block diagram illustrating a configuration example of a user signal selection / synthesis circuit.

FIG. 5 is a block diagram showing a configuration of another embodiment of the CDMA transmitting apparatus in the CDMA transmitting / receiving system according to the present invention.

FIG. 6 is a block diagram showing a configuration of another embodiment of the CDMA receiving apparatus in the CDMA transmitting / receiving system according to the present invention.

FIG. 7 is a block diagram showing a configuration of still another embodiment of a CDMA transmitting apparatus in a CDMA transmitting / receiving system according to the present invention.

FIG. 8 is a block diagram showing a configuration of still another embodiment of the CDMA receiving apparatus in the CDMA transmitting / receiving system according to the present invention.

FIG. 9 is a block diagram showing a configuration of still another embodiment of the CDMA transmitting apparatus in the CDMA transmitting / receiving system according to the present invention.

FIG. 10 is a block diagram showing a configuration of still another embodiment of the CDMA receiving apparatus in the CDMA transmitting / receiving system according to the present invention.

FIG. 11 is a block diagram showing a configuration of a conventional CDMA transmission / reception system, where (a) shows a configuration of a transmission device;
(B) shows the configuration of the receiving device.

[Explanation of symbols]

101-1 to 101-K ... user signal encoder, 102-
1 to 102-K: power control circuit, 103-1 to 103-
K: antenna selection / weighting circuit, 103a to 103n
... Calculator, 104-1 to 104-N ... Pilot encoder, 105-1 to 105-N ... Synthesizer, 106-1 to 1
06-N: delay device, 107-1 to 107-N: antenna, 201-1 to 201-N: pilot correlator, 20
2 ... User signal correlator, 203-1 to 203-N ... Detector, 204 ... User signal selection / synthesis circuit, 205-1 to 205-1
205-N: power measurement circuit, 206: antenna selection / weighting signal detection circuit, 211: signal quality detection circuit, 21
2 ... selection circuit, 212a ... combiner.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04J 13/00 H04B 7/06 H04B 7/08 H04B 7/26

Claims (4)

(57) [Claims] 1. A CDMA transmitting apparatus comprising: a CDMA transmitting apparatus; and a CDMA receiving apparatus, wherein the CDMA transmitting apparatus includes a plurality of transmitting antennas, a signal transmitting unit for transmitting a transmission signal having a different weight to each transmitting antenna, and a transmitting antenna. and a pilot signal transmitting means for transmitting to each transmit antenna corresponding pilot signal spread with different codes for each, the CDMA receiving apparatus, transmitting <br/> signal from a plurality of transmitting antennas of the CDMA transmitting apparatus a receiving means for obtaining a No., detects each pilot signal from the received signal of the receiving means
An FDD / CDMA transmission / reception system, wherein an antenna selection signal corresponding to a reception power value of each detected pilot signal is transmitted to the CDMA transmission device. 2. The FDD / CDMA transmission / reception system according to claim 1, wherein the transmission signal transmitted from the signal transmission unit is weighted so that the signal is transmitted to only one of a plurality of transmission antennas. . 3. A plurality of transmitting antennas of a CDMA transmitting apparatus
From multiple codes spread with different codes for each transmit antenna.
Means for receiving a pilot signal, and detecting and detecting a pilot signal from the received signal.
Antenna selection according to the received power value of each pilot signal
Means for generating a signal, and transmitting the generated antenna selection signal to the CDMA transmitting apparatus.
Means for transmitting to the device .
CDMA receiver. 4. A plurality of transmitting antennas, and each transmitting antenna has a different weight based on an antenna selection signal.
Signal transmitting means for transmitting a transmission signal with a predetermined number of codes, and a plurality of packets spread with different codes for each of the transmitting antennas.
Pi that sends out the pilot signal to each corresponding transmitting antenna
Lot signal transmitting means, and each pyro detected from the received signal by the CDMA receiver.
The antenna generated according to the received power value of the cut signal
Japanese to be configured to include a means for receiving a selection signal
CDMA transmitter.