JP3498796B2 - Array antenna receiver - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly applies a code division multiple access (hereinafter referred to as CDMA) communication system, and enables highly accurate path search in compensation (calibration) of characteristic differences between receiving circuits. A possible array antenna receiver.

[0002]

2. Description of the Related Art Conventionally, in an array antenna receiving apparatus of this type, a directivity pattern peak is directed to a desired wave which is a radio wave to be received, or a directivity pattern null is directed to an interference wave generated at the time of reception. To control SIR (signal power to interference power ratio) and SINR
Communication is performed after maximizing (signal power to interference and noise power ratio) etc. For example, when the array antenna receiving device is a base station for a mobile phone, it is possible to improve communication quality by controlling the directivity pattern so that the terminal device emits a desired wave.

However, in such array control, in the array antenna receiving apparatus, in the receiving circuit corresponding to each antenna element, the characteristics of analog elements such as amplifiers are varied independently, and the temperature characteristics and the temporal variation due to aging deteriorate each independently. Due to the characteristic difference of the phase and the amplitude, and the unknown amplitude fluctuation and the phase rotation are added, the directivity pattern is formed differently from the desired one. Such a characteristic difference between the receiving circuits causes a decrease in the reception gain, which leads to a deterioration in communication quality.

Therefore, in order to prevent such a problem, it is necessary for the array antenna receiving apparatus to calculate the characteristic difference of the phase and the amplitude in each receiving circuit and perform the calibration. Specifically, for each receiving circuit. Of the characteristics between the receiving circuits by calculating the calibration coefficient by calculating the characteristic difference of the phase and amplitude of the received signal and multiplying the phase and amplitude of the received communication signal by the phase component and amplitude component of the calculated calibration coefficient, respectively. Compensating for the difference. By performing the calibration at any time by such a method, the array antenna receiving device can always perform accurate directivity pattern control, so that the advantages of the array antenna receiving device can be maximized.

In order to perform such calibration accurately, it is necessary to use a calibration device that calculates the characteristic difference between the receiving circuits based on the calibration signal. For example, in the calibration device of the array antenna radio receiving device disclosed in Japanese Patent Laid-Open No. 11-46180, a spread signal in the same frequency band as the spread signal used for communication is used as the calibration signal. Further, in order to perform the calibration at any time, it is necessary to have a configuration for performing the calibration during the communication. However, in the calibration device here, the calibration signal is multiplexed with the communication signal during the communication. It is possible to perform calibration, which enables communication while always compensating for characteristic differences between receiving circuits.

FIG. 6 is a circuit block diagram showing the basic configuration of an array antenna receiving apparatus according to the conventional CDMA communication system.

This array antenna receiving apparatus uses a CDMA
A communication system is applied, and a characteristic difference between receiving circuits is compensated for by using a calibration device (a calibration device for an array antenna radio receiving device disclosed in Japanese Patent Laid-Open No. 11-46180). The array antenna receiving device is integrated with the calibration device, and if the basic configuration is divided into functional blocks, the calibration signal generated in the baseband band is spread-modulated and then processed into the same radio band as the communication signal. A calibration signal transmission unit that performs frequency conversion and transmission, and a reception process of a multiplexed radio signal that is a multiplex of a radio band communication signal and a calibration signal received for each reception circuit corresponding to a predetermined number of antenna elements. A wireless processing unit that frequency-converts into a baseband band to generate a predetermined number of multiplexed baseband signals, and a searcher unit that detects synchronization timing in a calibration signal included in the predetermined number of multiplexed baseband signals in the baseband band. And the result of this synchronization timing detection is used. A calibration processing unit that calculates a predetermined number of calibration coefficients for each brazing signal, and a reception signal that uses a predetermined number of calibration coefficients for a communication signal included in a predetermined number of multiplexed baseband signals in the baseband. The communication processing unit is configured to add and combine a predetermined number of demodulated signals obtained by performing demodulation processing while compensating for characteristic differences between circuits, and performing reception output by an array antenna.

Of these, the calibration signal transmitting section spreads the calibration signal to the baseband calibration signal 301 and the calibration signal generating section 300 which outputs the baseband calibration signal 301 in which the calibration signal is generated in the baseband. A spreading modulator 302 that outputs a spread-modulated baseband calibration signal 303 by multiplying a code and performing spread-modulation processing, and frequency-converts the spread-modulated baseband calibration signal 303 into a radio band. Wireless transmission section 304 that outputs a wireless calibration signal 305 by wireless
Is a natural number of 2 or more) and outputs the wireless calibration signals 307-1 to 307-N.
6 and 6. However, N indicating the number of distributions in the distributor 306 is the antenna unit 3 for receiving a communication signal.
The number is equal to the number of antenna elements constituting 08, and the number of N does not matter here.

The wireless processing section includes an antenna section 308 composed of N antenna elements for receiving communication signals, and N wireless communication signals 309-received by the antenna section 308.
1 to 309-N and N wireless calibration signals 3
07-1 to 307-N and N couplers 310 that output N multiplexed radio signals 311-1 to 311-N.
-1 to 310-N and N multiplex radio signals 311-1 to 311-N are frequency-converted into a baseband band for reception processing, and N multiplex baseband signals 313-1 to 311-
N radio receiving units 312-1 to 312 which output 3-N
-N and.

The calibration processing section detects the synchronization timing in the calibration signals included in the N multiplexed baseband signals 313-1 to 313-N to obtain N synchronization timing signals 315-1 to 315.
-N is used to calibrate each of the calibration signals included in the N baseband multiplexed signals 313-1 to 313-N using the N synchronization timing signals 315-1 to 315-N. Calibration coefficient calculation units 316-1 to 316-N that output N calibration coefficient signals 317-1 to 317-N indicating the result of calculating the calibration coefficient.
Composed of and.

The communication processing unit has N calibration coefficient signals 317-1 to 31-31 for the communication signals included in the N multiplexed baseband signals 313-1 to 313-N.
N communication signals that output N demodulated signals 319-1 to 319-N by performing demodulation processing while compensating for the characteristic difference between the receiving circuits by multiplying the calibration coefficients indicated by 7-N respectively. Demodulation units 318-1 to 318-N
And N demodulated signals 319-1 to 319-N are added and combined to perform reception output by the array antenna.
Composed of and.

In the case of this array antenna receiving apparatus, by using the baseband calibration signal 303 which is spread-modulated by the spread modulator 302 in the calibration signal transmitter, the search processing is performed by the searcher unit 314 in the calibration processing unit. Is performed to detect the synchronization timing in the calibration signal included in the N multiplexed baseband signals 313-1 to 313-N. In the above-mentioned Japanese Patent Laid-Open No. 11-46180, the searcher unit 314
Although not described in detail, the searcher unit 314 to which the CDMA communication system is applied includes a delay profile generation circuit and a path search circuit for enabling the output of synchronization timing for the number of normal reception circuits. To be done.

FIG. 7 is a circuit block diagram showing a detailed configuration of the searcher section 314 provided in the array antenna receiving apparatus described above.

The searcher unit 314 includes N multiplexed baseband signals 400-1 to 400-N (N multiplexed baseband signals 313-1 to 313-N described above) and N contained therein. A delay profile, which is a correlation value obtained by correlating with a known spread code sequence (here, spread code) used in spread modulation processing in spread modulation unit 302 during generation and transmission of a calibration signal, is generated. N delay profile signals 402-1 to 402 for N calibration signals
N delay profile generation circuits 4 that output −N
01-1 to 401-N and N synchronization timing signals 40 indicating the results of path search performed on the N delay profile signals 402-1 to 402-N, respectively.
4-1 to 404-N (which become the above-mentioned N synchronization timing signals 315-1 to 315-N) and N path search circuits 403-1 to 403-N. ing.

Incidentally, as another well-known technique related to the above-mentioned array antenna receiving apparatus, there is Japanese Patent Laid-Open No. 11-3.
The array antenna wireless communication device disclosed in Japanese Patent No. 12917 or Japanese Patent Laid-Open No. 2000-295152 can be used.

[0016]

In the case of the above-mentioned array antenna receiving apparatus, when the calibration processing unit processes the calibration signal transmitted from the calibration signal transmitting unit, the calibration signal is transmitted from the wireless processing unit. Since it becomes an interference source with respect to the signal, it is required to keep the transmission level of the calibration signal as low as possible. However, if the transmission level of the calibration signal is low, multiplexing by the searcher unit provided in the calibration processing unit is required. When detecting the synchronization timing in the calibration signal included in the baseband signal, the level of the path on the delay profile indicated by the delay profile signal also becomes low, so it is not possible to accurately detect the synchronization timing at such a low path level. There is a problem that Tsu.

As described above, if the synchronization timing cannot be accurately detected by the searcher unit in the calibration processing unit, the calibration coefficient including the information of the characteristic difference between the receiving circuits of the phase and the amplitude necessary for the calibration is accurately calculated. Therefore, the accuracy of the calibration is deteriorated, and as a result, the directional pattern formed by the array antenna receiving apparatus is deviated by the error of the calibration coefficient, which causes the deterioration of the communication quality. become.

The present invention has been made to solve such a problem, and its technical problem is that the level of the path is low even under the condition that the transmission level of the calibration signal is suppressed as low as possible. An object of the present invention is to provide an array antenna receiving apparatus capable of detecting synchronization timing in a calibration signal included in a multiplexed baseband signal with accuracy and high precision.

[0019]

According to the present invention, a CDM
In an array antenna receiving apparatus to which the A communication method is applied, a communication signal of a radio band received by each receiving circuit corresponding to a predetermined number of antenna elements and a same signal as the communication signal after being subjected to spread modulation processing in a base band band The calibration included in a predetermined number of multiple baseband signals obtained by frequency-converting a multiplex radio signal obtained by frequency-converting into a radio band and transmitting and transmitting the calibration signal into a baseband band by reception processing When detecting the synchronization timing in the signal, the delay profile for the number of the receiving circuits is obtained by taking the correlation value between the predetermined number of multiplexed baseband signals and the known spreading code sequence used in the spreading modulation processing. Is added and synthesized, and only the maximum path is path searched for the delay profile obtained by the additive synthesis. Calibration path search method of an array antenna receiving apparatus characterized by is obtained.

On the other hand, according to the present invention, in the array antenna receiving apparatus to which the CDMA communication system is applied, in the radio band communication signal and the base band band received by each receiving circuit corresponding to a predetermined number of antenna elements. A predetermined number of signals obtained by frequency-converting to a baseband band by receiving processing a multiplexed wireless signal obtained by multiplexing a calibration signal that has been frequency-converted into the same wireless band as the communication signal and transmitted and transmitted after spread-modulation processing. In the searcher unit that detects the synchronization timing in the calibration signal included in the multiplex baseband signal, the correlation value between the predetermined number of multiplex baseband signals and the known spreading code sequence used in the spreading modulation process is obtained. Delay profile generation circuits that generate delay profiles and delay profiles for the number of reception circuits And a delay profile combining circuit for adding and combining, searcher section for calibration of the array antenna receiving apparatus that includes a path search circuit to pass search only the maximum path is obtained for the delay profile obtained by additive synthesis.

On the other hand, according to the present invention, the calibration signal generated in the baseband band is spread-modulated and then frequency-converted into the same radio band as that of the communication signal for transmission and transmission, and a predetermined number. The multiplex wireless signal obtained by multiplexing the communication signal of the wireless band and the calibration signal received by each receiving circuit corresponding to the antenna element is frequency-converted into the baseband band by the receiving process to generate a predetermined number of multiple baseband signals. A wireless processing unit for generating and a searcher unit for detecting a synchronization timing in a calibration signal included in a predetermined number of multiple baseband signals in a baseband are included, and the calibration is performed by using a detection result of the synchronization timing. A calculator that calculates a predetermined number of calibration coefficients for each signal. The demodulation process is performed while compensating for the characteristic difference between the reception processing circuit using the predetermined number of calibration coefficients for the communication signal included in the predetermined number of multiplexed baseband signals in the baseband band CDMA including a communication processing unit that adds and synthesizes a predetermined number of obtained demodulated signals to perform reception output by an array antenna
In the array antenna receiving device to which the communication method is applied,
The searcher unit adds and synthesizes delay profiles corresponding to the number of receiving circuits obtained by obtaining a correlation value between a predetermined number of multiplexed baseband signals and a known spread code sequence used in the spread modulation processing for detecting synchronization timing. An array antenna receiving apparatus including a path search circuit that searches only the maximum path for the delay profile obtained by the addition and synthesis is obtained.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

First, a technical outline of a calibration path search method for an array antenna receiving apparatus applied to the array antenna receiving apparatus of the present invention will be briefly described. This path search method is, in an array antenna receiving apparatus to which a CDMA communication system is applied, performs spread modulation processing in a communication signal in a radio band and a baseband band received by each receiving circuit corresponding to a predetermined number of antenna elements. A predetermined number of multiplexed baseband signals obtained by frequency-converting the multiplexed wireless signal that has been frequency-converted to the same wireless band as the communication signal and transmitted and transmitted to the calibration signal to the baseband band by reception processing When the synchronization timing is detected in the calibration signal included in, the reception obtained by taking the correlation value between the predetermined number of multiplexed baseband signals and the known spreading code sequence used in the spreading modulation processing of the calibration signal The delay profiles for the number of circuits are added and combined, and the delay profiles obtained by this addition and combination are It is intended to pass search only the maximum path to the file.

According to this path search method, when the path search is performed for the delay profile obtained by the addition synthesis, the calibration signal has only a single synchronization timing, and therefore the path search is performed only for the maximum path.
The search signal is used to accurately and accurately include the calibration signal contained in the multiplexed baseband signal even if the level of the path is low under the condition that the transmission level of the calibration signal is kept as low as possible. It is possible to detect the synchronization timing in. In this way, if the synchronization timing can be accurately detected, the calibration coefficient including the information of the characteristic difference between the receiving circuits of the phase and the amplitude necessary for the calibration can be accurately calculated, and the accuracy of the calibration is improved. As a result, it is possible to improve the communication quality without causing the deviation of the calibration coefficient error in the directivity pattern formed by the array antenna receiving device.

FIG. 1 is a circuit block diagram showing a basic configuration of an array antenna receiving apparatus by a CDMA communication system according to an embodiment to which the above-described calibration path search method of the array antenna receiving apparatus of the present invention is applied. is there.

Also in the case of this array antenna receiving apparatus, as in the conventional apparatus described in FIG. 6, the CDMA communication system is applied, and when the basic configuration is divided into functional blocks, the calibration generated in the baseband band. A calibration signal transmission unit that performs spread modulation processing of the transmission signal and then frequency-converts and transmits it to the same wireless band as the communication signal, and a communication signal of the wireless band received by each receiving circuit corresponding to a predetermined number of antenna elements A wireless processing unit that frequency-converts a multiplex wireless signal obtained by multiplexing a calibration signal and a calibration signal into a baseband band by reception processing, and a predetermined number of multiplex baseband signals in the baseband band. Including a searcher unit that detects the synchronization timing in the calibration signal contained in In addition, a calibration processing unit that calculates a predetermined number of calibration coefficients for each calibration signal using the detection result of the synchronization timing, and a communication signal included in a predetermined number of multiple baseband signals in the baseband. And a communication processing unit that adds and combines a predetermined number of demodulated signals obtained by performing demodulation processing while compensating for characteristic differences between receiving circuits using a predetermined number of calibration coefficients, and performing reception output by an array antenna. It has been configured.

Of these, the calibration signal transmission unit spreads the calibration signal to the calibration signal generation unit 100 that outputs the baseband calibration signal 101 generated by generating the calibration signal in the baseband and the baseband calibration signal 101. A spread modulation unit 102 that outputs a spread-modulated baseband calibration signal 103 by performing a spread-modulation process by multiplying a code, and frequency-converts the spread-modulated baseband calibration signal 103 into a radio band. Wireless transmission unit 104 that outputs a wireless calibration signal 105 by using the wireless calibration signal 105 N (N
Is a natural number greater than or equal to 2) and outputs the wireless calibration signals 107-1 to 107-N.
6 and 6. However, N, which indicates the number of distributions in the distributor 106, is the antenna unit 1 for receiving a communication signal.
The number is equal to the number of antenna elements constituting 08, and the number of N does not matter here.

The radio processing section includes an antenna section 108 composed of N antenna elements for receiving communication signals, and N radio communication signals 109-received by the antenna section 108.
1 to 109-N and N wireless calibration signals 1
07-1 to 107-N and N couplers 110 that output N multiplexed radio signals 111-1 to 111-N.
-1 to 110-N and N multiplexed radio signals 111-1 to 111-N
It is composed of N radio receiving units 112-1 to 112-N which frequency-convert 111-N into a baseband band and output N multiplexed baseband signals 113-1 to 113-N.

The calibration processing unit detects the synchronization timing in the calibration signals included in the N multiplexed baseband signals 113-1 to 113-N to generate N synchronization timing signals 115-1 to 115.
Using the searcher unit 114 that outputs -N and the N synchronization timing signals 115-1 to 115-N, the calibration signals included in the N baseband multiplexed signals 113-1 to 113-N are respectively calibrated. Calibration coefficient calculation units 116-1 to 116-N which output N calibration coefficient signals 117-1 to 117-N indicating the result of calculation of the calibration coefficient.
Composed of and.

However, N synchronization timing signals 115-1 to 115 output from the searcher unit 114 here.
-N indicates that the basic configuration for detecting the synchronization timing in the searcher unit 114 is the same as that of the conventional searcher unit 314, as suggested by the configuration in which one system is branched and constructed as an N system. Compared to different. That is, when the searcher unit 114 detects the synchronization timing in the calibration signal included in the N multiplexed baseband signals 113-1 to 113-N,
For the number of receiving circuits obtained by obtaining the correlation value between the multiple baseband signal and the known spreading code sequence (here, the spreading code multiplied) used for the spreading modulation processing in the spreading modulation unit 102 in the calibration signal transmitting unit. One line of synchronization timing signal of calibration signal with only single synchronization timing obtained by adding and combining delay profiles and performing path search for only the maximum path for the delay profile obtained by this adding and combining Is output as.

Incidentally, the searcher unit 114 here is the one to which the above-described calibration path search method of the array antenna receiving device is applied, that is, the array antenna receiving device to which the CDMA communication system is applied, and the antenna unit 108 is provided. Communication signals 109-1 to 10-10 of the radio band received by each receiving circuit corresponding to the predetermined number of antenna elements of
Radio calibration signals 107-1 to 107-1 to 10-N, which are frequency-converted to the same radio band as the communication signals 109-1 to 109-N after being spread and modulated in the baseband and 9-N.
107-N and multiplexed radio signals 111-1 to 111-1
11-N is a predetermined number of multiplexed baseband signals 113-N obtained by frequency conversion into a baseband band by reception processing.
1 to 113-N, when the synchronization timing in the calibration signals included in the calibration signals is detected, the searcher unit 114 spreads the predetermined number of multiplexed baseband signals 113-1 to 113-N and the calibration signals. A delay profile generation circuit that takes a correlation value with a known spreading code sequence (multiplied spreading code) used in modulation processing to generate a delay profile; and a delay profile combining circuit that adds and combines delay profiles for the number of receiving circuits, A path search circuit that searches only the maximum path for the delay profile obtained by the addition synthesis is provided.

FIG. 2 is a circuit block diagram showing a detailed configuration of the searcher section 114 here.

The searcher unit 114 includes multiple baseband signals 200-1 to 200-N (N multiple baseband signals 113-1 to 113-N described above) and N calibration signals included therein. N is generated by generating a delay profile which is a correlation value obtained by taking a correlation with a known spread code sequence (multiplied spread code) that has been spread and modulated by the spread modulator 102 during generation and transmission of
Delay profile signals 202-1 to 202-N
N delay profile generation circuits 201 for outputting
-1 to 201-N and N delay profile signals 202-1 to 202-N are added and combined to output a delay profile signal 204, and a path search is performed on the delay profile signal 204. And a path search circuit 205 for outputting a sync timing signal 206 (which becomes the above-mentioned N sync timing signals 115-1 to 115-N) indicating the result of detecting the sync timing. .

However, here, the path search circuit 205
Detects the synchronization timing of the calibration signal by performing a path search from the delay profile signal 204 added and synthesized by the delay profile synthesis circuit 203. However, since the calibration signal at this time has only a single synchronization timing, The search circuit 205 detects only the maximum path.

FIG. 3 shows a comparison of input / output signal waveforms in the delay profile synthesis circuit 203 of the searcher section 114.

Here, for example, when the waveforms of the delay profile signals 202-1 to 202-3 have the shapes shown in the figure, the delay profile combining circuit 203 adds and combines these waveforms to obtain the delay profile signal 204.
Output as, it is possible to improve the SN ratio of the delay profile by changing the shape as shown in the waveform and averaging the noise level. Therefore, the conventional searcher unit 314 as shown in FIG. It is possible to detect even a path that seems to be buried in noise in each delay profile that was impossible, and it is shown that the path search circuit 205 can perform a more accurate path search. Therefore, in the delay profile after addition and synthesis, the noise level is averaged and SN
The ratio is improved, and more accurate path search becomes possible.

FIG. 4 is a waveform diagram schematically showing how paths are allocated in the delay profile signal during multipath.

Generally, for example, when an array antenna receiving device is used as a base station, when the base station receives a communication signal from a terminal device, many reflected waves other than the direct wave are usually included in the received signal due to the radio propagation environment. Assuming that the delay profile signal 204 is generated from such a received signal, the delay profile signal 204 has several paths P1 to P5 as shown in FIG. . As described above, in the case of the searcher unit that is generally used for receiving the communication signal, the searcher unit is normally configured to search a plurality of paths.

However, in the case of the array antenna receiving apparatus here, since the calibration signal does not propagate in the air like a communication signal, multipath does not occur.

FIG. 5 shows the allocation of paths at the time of inputting a calibration signal included in the multiple baseband signals 200-1 to 200-N in the delay profile signal 204 output from the delay profile combining circuit 203 of the searcher unit 114. FIG. 6 is a waveform diagram schematically showing the situation. Here, when the path search circuit 205 outputs the synchronization timing signal 206, the maximum path P
It shows that only 1 is searched and then output. That is, in the searcher unit 114, when detecting the synchronization timing of the input calibration signal, it is sufficient to detect only a single path. Therefore, as shown in FIG. 4, each of the delay profile signals 204 at the time of multipath is detected. It suffices to operate so as to search only the maximum path P1 from those corresponding to the paths P1 to P5 as shown in FIG. As a result, only the synchronization timing of the calibration signal is constantly input to the calibration coefficient calculation units 116-1 to 116-N (the synchronization timing other than the calibration signal is set to the calibration coefficient calculation units 116-1 to 116-N. Therefore, the calculation accuracy of the calibration coefficient is improved.

Therefore, by using such a searcher unit 114, it is possible to perform a highly accurate path search, so that the calibration coefficient calculation units 116-1 to 116-N in the calibration processing unit are more accurate. The calibration coefficient can be calculated using different synchronization timings.

By the way, each delay profile signal 2
The reason why it is not necessary to independently perform the path search for each of the 02-1 to 202-N is that the calibration signals generated and transmitted from the same calibration signal transmission unit are transmitted to different reception circuits in the wireless processing unit. It can be considered that the difference in synchronization timing when reaching the searcher unit 114 can be regarded as a level that can be ignored. That is, when the chip rate adopted in the CDMA communication system is 3.84 Mchip / s, 1c
Since the hip is about 78 m, even if the length of the cable used when configuring the array antenna receiver and the error of the transmission path difference on the circuit can be suppressed to 1 m, 0.01c
This is a calculation that only produces an error in hip. This is a sufficiently negligible level, considering that the resolution of the delay profile generated by the searcher unit 114 in the calibration processing unit of the array antenna receiving device actually used is a fraction of a chip unit. I can say.

The communication processing unit has N calibration coefficient signals 117-1 to 11-11 for the communication signals included in the N multiplexed baseband signals 113-1 to 113-N.
N-communications signals that output N demodulated signals 119-1 to 119-N by performing demodulation processing while compensating for the characteristic difference between the receiving circuits by multiplying the calibration coefficients indicated by 7-N respectively. Demodulation units 118-1 to 118-N
And N demodulated signals 119-1 to 119-N are added and combined to perform reception output by the array antenna.
Composed of and.

The operation of this array antenna receiving apparatus will be described below. In the calibration signal transmission section, the baseband calibration signal 101 generated by the calibration signal generation section 100 in the baseband is used as the spread modulation section 102.
The baseband calibration signal 101 is transmitted and output to the wireless transmission unit 104 as the baseband calibration signal 103 subjected to the spread modulation processing by modulating the baseband calibration signal 101 with a spread code. The wireless transmission unit 104 frequency-converts the spread-modulation-processed baseband calibration signal 103 in a wireless band and delivers it as a wireless calibration signal 105 to a distributor 106, which distributes N wireless calibration signals 105. The distributed wireless calibration signals 107-1 to 107-N are delivered to the couplers 110-1 to 110-N in the wireless processing unit.

In the wireless processing section, the communication signal is received by the N antenna elements in the antenna section 108, and the couplers 110-1 to 110-1 as the wireless communication signals 109-1 to 109-N are received.
Handed over to 110-N. Couplers 110-1 to 110
In -N, N wireless multiplexing signals 107-1 to 107-N delivered from the distributor 106 in the calibration signal transmitting unit and wireless communication signals 109-1 to 109-N from the antenna unit 108 are multiplexed. Of the multiplex wireless signals 111-1 to 111-N of the wireless reception unit 112.
-1 to 112-N for transmission and output to the wireless reception unit 112-1
-112-N, multiplex radio signal 111-
N-multiple baseband signals 113-111 obtained by frequency converting 1-111-N to baseband
1 to 113-N are the searcher unit 114 and the calibration coefficient calculation unit 1 in the calibration processing unit.
16-1 to 116-N and the communication signal demodulation units 118-1 to 118-N in the communication processing unit are distributed and delivered.

In the calibration processing section, in the searcher section 114, the multiplexed baseband signal 113-1
To 113-N, the synchronization timing in the calibration signal included in each of the -113-N is accurately detected for the calibration signal having only a single synchronization timing by the above-described function.
6, but outputs the synchronization timing signal 206 of one system to the calibration coefficient calculation units 116-1 to 116-N as the synchronization timing signals 115-1 to 115-N branched into N in the device configuration. Is transmitted. Calibration coefficient calculation unit 116-1
116-N, the synchronization timing signals 115-1 to 11-11
Radio receiver 112 in the radio processor using 5-N-
1-112-N transmitted baseband multiplexed signal 1
Calibration coefficient signals 117-1 to 117-N obtained by calculating the characteristic difference of the phase and amplitude for each receiving circuit for the calibration signals in 13-1 to 113-N.
Communication signal demodulation units 118-1 to 11 in the communication processing unit
Hand over to 8-N.

However, in the searcher unit 114, the spread modulation unit 10 transmits the calibration signals included in the baseband multiplexed signals 113-1 to 113-N at the time of transmission.
By correlating with the spread code multiplied in 2, only the calibration signal can be code-separated.
In addition, the calibration coefficient calculation units 116-1 to 116
The calibration coefficient calculated by −N indicates the characteristic variation with respect to the reference value of the phase or amplitude of the calibration signal. The reference value is often the value of the reference antenna element or a value set arbitrarily, but the setting method is not limited here. Furthermore, it does not matter here whether the calibration coefficient is for both the phase value and the amplitude value, or for which one.

In the communication processing section, the communication signal demodulation section 11
8-1 to 118-N, N calibration coefficient signals 117-1 to 117 for communication signals included in N multiplexed baseband signals 113-1 to 113-N.
-N demodulated signals 119-1 to 119-obtained by performing demodulation processing while compensating for the characteristic difference between the receiving circuits by multiplying each by the calibration coefficient indicated by N
The N is output and transmitted to the adder 120. In the adding section 120,
The N demodulated signals 119-1 to 119-N are added and combined to perform reception output by the array antenna.

However, the communication signal demodulation units 118-1 to 118
-N, N multiple baseband multiplexed signals 113-1
~ N can be code-separated by correlating with the spread code multiplied to perform spread modulation processing when transmitting the communication signal, and the calibration coefficient signals 117-1 to 117-1 to the communication signal. By multiplying by 117-N and demodulating, demodulation can be performed while compensating for the characteristic difference in each receiving circuit.

In such an operation, in the array antenna receiving apparatus, the calibration processing unit can calculate the calibration coefficient more accurately and accurately, and the calculated calibration coefficient is stored in the communication processing unit. Since the communication signal is transmitted and the communication signal is compensated by the communication processing unit, calibration can be performed with high accuracy as the entire device. Therefore, in this array antenna receiving device, if highly accurate calibration is performed at any time,
Since the directivity pattern can always be controlled with high accuracy, it is possible to receive the communication signal while keeping the communication quality to the maximum.

[0051]

As described above, according to the present invention, after the spread modulation processing in the base band, the calibration signal frequency-converted into the same radio band as the communication signal and the predetermined number of antenna elements are supported. Synchronization in the calibration signal included in a predetermined number of multiple baseband signals obtained by frequency-converting multiplex wireless signals obtained by multiplexing the wireless band communication signals received by each receiving circuit to the baseband band by reception processing When performing timing detection,
The delay profiles for the number of receiving circuits obtained by taking the correlation value between the predetermined number of multiplexed baseband signals and the known spreading code sequence used in the spreading modulation processing of the calibration signal are added and combined, and obtained by this addition and combining. When the path search is performed for the specified delay profile, the path search can be performed only for the maximum path because the calibration signal at this time has only a single synchronization timing. It becomes possible to detect the synchronization timing in the calibration signal included in the multiplex baseband signal accurately and accurately even if the path level is low under the condition that is kept as low as possible. As a result, since the synchronization timing can be accurately detected, it is possible to accurately calculate the calibration coefficient including the information on the characteristic difference between the receiving circuits of the phase and the amplitude necessary for the calibration, and the accuracy of the calibration is improved. As a result, it is possible to improve the communication quality without causing a deviation of the calibration coefficient error in the directivity pattern formed by the array antenna receiving apparatus.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing a basic configuration of an array antenna receiving apparatus by a CDMA communication system according to an embodiment to which a calibration path search method of an array antenna receiving apparatus of the present invention is applied.

FIG. 2 is a circuit block diagram showing a detailed configuration of a searcher unit included in the array antenna receiving apparatus shown in FIG.

FIG. 3 is a diagram showing, in comparison, input / output signal waveforms in the delay profile combining circuit of the searcher unit shown in FIG.

4 is a waveform diagram schematically showing how paths are allocated in multipath in a delay profile signal output from the delay profile combining circuit of the searcher unit shown in FIG.

5 is a waveform diagram schematically showing how paths are allocated when a calibration signal is input in the delay profile signal output from the delay profile combining circuit of the searcher unit shown in FIG.

FIG. 6 is a circuit block diagram showing a basic configuration of an array antenna receiving apparatus according to a conventional CDMA communication system.

7 is a circuit block diagram showing a detailed configuration of a searcher unit provided in the array antenna receiving apparatus shown in FIG.

[Explanation of symbols]

100,300 Calibration signal generation unit 101,103,301,303 Baseband calibration signal 102,302 Spread modulation unit 104,304 Radio transmission unit 105,107-1 to 107-N, 305,307-1
To 307-N wireless calibration signals 106 and 306 distributors 108 and 308 antenna units 109-1 to 109-N, 309-1 to 309-N wireless communication signals 110-1 to 110-N, 310-1 to 310- N couplers 111-1 to 111-N, 200-1 to 200-N, 3
11-1 to 311-N, 400-1 to 400-N multiplex radio signals 112-1 to 112-N, 312-1 to 312-N radio receiving sections 113-1 to 113-N, 313-1 to 313- N multiple baseband signals 114, 314 Searcher units 115-1 to 115-N, 206, 315-1 to 315
-N, 404-1 to 404-N synchronization timing signal 11
6-1 to 116-N, 316-1 to 316-N calibration coefficient calculation units 117-1 to 117-N, 317-1 to 317-N calibration coefficient signals 118-1 to 118-N, 318-1 To 318-N communication signal demodulation units 119-1 to 119-N, 319-1 to 319-N demodulation signals 120, 320 addition units 201-1 to 201-N, 401-1 to 401-N delay profile generation circuit 202 -1 to 202-N, 204, 402-1 to 402
-N delay profile signal 203 delay profile synthesis circuit 205, 403-1 to 403-N path search circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 2001-36451 (JP, A) JP 2000-307489 (JP, A) JP 11-46180 (JP, A) JP 2001-251124 (JP , A) JP 2001-345747 (JP, A) JP 2000-353986 (JP, A) JP 11-312917 (JP, A) Akio Aoyama, Naomasa Yoshida, Akihisa Gokawa, Utilize delay profile of antenna synthesis CDMA Path Search Method, IEICE Technical Report, Japan, The Institute of Electronics, Information and Communication Engineers, July 23, 1999, Vol. 99, No. 220, p. 25-30 (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04B 1/69-1/707 H04J 13/00-13/06

Claims (3)

(57) [Claims] 1. An array antenna receiving apparatus to which a code division multiple access communication system is applied, wherein spread spectrum modulation processing is performed in a radio band communication signal and a base band band received by each receiving circuit corresponding to a predetermined number of antenna elements. After that, a predetermined number of multiple basebands obtained by frequency-converting a multiplex radio signal obtained by multiplexing the calibration signal transmitted and transmitted by frequency conversion into the same radio band as the communication signal to the baseband band by the receiving process When detecting the synchronization timing in the calibration signal included in the signal, it is obtained by taking the correlation value between the predetermined number of multiplexed baseband signals and the known spreading code sequence used in the spreading modulation processing. The delay profiles for the number of the receiving circuits are added and combined, and the delay profiles obtained by the addition and combination are the maximum. A path search method for calibration of an array antenna receiving apparatus, characterized in that only a large path is path searched. 2. An array antenna receiving apparatus to which a code division multiple access communication system is applied, wherein spread spectrum modulation processing is performed in a radio band communication signal and a base band band received by each receiving circuit corresponding to a predetermined number of antenna elements. After that, a predetermined number of multiple basebands obtained by frequency-converting a multiplex radio signal obtained by multiplexing the calibration signal transmitted and transmitted by frequency conversion into the same radio band as the communication signal to the baseband band by the receiving process In the searcher unit for detecting the synchronization timing in the calibration signal included in the signal, the delay profile is obtained by taking the correlation value between the predetermined number of multiplexed baseband signals and the known spreading code sequence used in the spreading modulation processing. The delay profile generation circuit that generates A delay profile synthesizing circuit that performs arithmetic synthesis, and a path that searches only the maximum path for the delay profile obtained by the additive synthesis.
A searcher unit for calibration of an array antenna receiving device, comprising a search circuit. 3. A calibration signal transmitting unit that performs spread modulation processing of a calibration signal generated in a baseband band, and then performs frequency conversion into the same wireless band as a communication signal and transmits and transmits the signal, and a calibration signal transmitting unit that corresponds to a predetermined number of antenna elements. Radio processing for frequency-converting a multiplexed radio signal obtained by multiplexing the communication signal and the calibration signal in the radio band received for each receiving circuit into a baseband band by reception processing to generate a predetermined number of multiplexed baseband signals And a searcher unit for detecting synchronization timing in the calibration signal included in the predetermined number of multiplexed baseband signals in the baseband band, and the calibration signal using the detection result of the synchronization timing. A carrier that calculates a predetermined number of calibration coefficients for Demodulation while compensating for the characteristic difference between the brazing processing unit and the communication signal included in the predetermined number of multiplexed baseband signals in the baseband using the predetermined number of calibration coefficients. In an array antenna receiving device to which a code division multiple access communication system is applied, which includes a communication processing unit that adds and combines a predetermined number of demodulated signals obtained by performing processing and performs reception output by an array antenna, the searcher unit is A delay profile generation circuit that takes a correlation value between the predetermined number of multiplexed baseband signals and a known spreading code sequence used in the spreading modulation processing to generate a delay profile, and the delay profiles for the number of reception circuits are added and combined. For the delay profile synthesis circuit and the delay profile obtained by the additive synthesis, Array antenna receiving apparatus characterized by comprising a path search circuit to pass search only the maximum path.