JP2005348236A - Array antenna transmitter and receiver, and calibration method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmitter employing an array antenna in which high precision calibration is realized while simplifying the configuration. <P>SOLUTION: The array antenna receiver having an array antenna constituted of a plurality of antenna elements comprises: a means for dividing the bandwidth of a transmission signal into a plurality of blocks; a first transmission calibration value calculating means for calculating a calibration value common to transmission signals in the block by averaging the transmission signals in the divided block; and a means for correcting an amplitude deviation and a phase deviation occurring between the branches of a transmission circuit provided in correspondence with each of the plurality of antenna elements. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an array antenna transmitter, a receiver, and a calibration method.

  As an advance from the third generation mobile communication, an even higher speed transmission is assumed, and an adaptive array antenna is an important technology for realizing the service. This adaptive array antenna uses a plurality of antenna elements, weights received signals appropriately, combines them, directs the main beam in the direction of arrival of the desired signal, and forms a directional zero in the direction of arrival of the interference signal The directivity can be controlled.

  In the adaptive array antenna as described above, in order to generate a transmission / reception beam with a high-precision main beam / null directed to the actual signal arrival direction of the desired wave / interference wave signal, in the uplink / downlink, It is necessary to perform calibration to compensate for the phase / amplitude deviation generated between the RF transmission circuit / reception circuit branches corresponding to the number of antennas. Here, calibration in the RF transmission circuit is called RF transmission circuit calibration, calibration in the RF reception circuit is called RF reception circuit calibration, and a general term for RF transmission circuit calibration and RF reception circuit calibration is RF radio circuit calibration. This is called

  FIG. 4 is a block diagram showing a configuration example of a conventional RF radio transmission circuit using an adaptive array antenna, and FIG. 5 is a block diagram showing a configuration example of a conventional RF radio reception circuit using an adaptive array antenna. is there. As shown in the figure, RF transmitter / receiver circuits are provided in parallel for the number of antenna branches (B). Since the RF transmission circuit / reception circuit for each antenna branch has the same configuration, an RF transmission circuit / reception circuit for antenna branch # 1 will be described as an example here.

  As shown in FIG. 4, the RF transmission circuit # 1 includes a digital / analog signal conversion processing unit 102, a quadrature modulation unit 103, a mixer (multiplier) 104, and a high-power amplifier 105.

  An input signal input to the digital / analog signal conversion processing unit 102 is digital-analog converted and orthogonally modulated by the orthogonal modulation unit 103. The signal subjected to quadrature modulation by the quadrature modulation unit 103 is frequency-converted (up-converted) by the mixer 104, which is a non-linear circuit, with the local frequency, amplified by the high-power amplifier 105, and then transmitted via the antenna.

  On the other hand, as shown in FIG. 5, the RF receiver circuit # 1 includes a low noise amplifier 202, a mixer (multiplier) 203, a band-limited pass filter 204, and an automatic gain control unit (AGC (Automatic Gain Control) circuit). ) 205, a quadrature detection unit 206, a reception level measurement unit 207, and an analog / digital signal conversion processing unit 208.

  An RF (Radio Frequency) received signal received via an antenna is amplified by a low noise amplifier 202, then frequency-converted (down-converted) by a local frequency and a mixer 203, passes through a band-limited pass filter 204, and is AGCed. Input to the circuit 205. The AGC circuit 205 controls the amplification gain so that the reception level measured after quadrature detection is constant. The received signal output from the AGC circuit 205 is analog-to-digital converted by the analog / digital signal conversion processing unit and output to the subsequent stage as an output signal.

  When a radio frequency (RF) signal passes through the RF transmitter / receiver circuit as described above, the amplitude / phase deviation between the antenna branches is affected by individual elements of amplifiers, mixers, and other active elements and parts constituting the circuit. Will appear as. In particular, the influence of individual differences between the AGC circuit in the RF receiving circuit and the high-power amplifier in the RF transmitting circuit becomes prominent. These influences cause degradation of adaptive array antenna characteristics, causing a problem that directivity different from expected directivity is formed. Therefore, in order to prevent the influence, it is necessary to perform calibration so that the characteristics of the RF transmission circuit / reception circuit are the same. That is, calibration technology is indispensable for realizing an adaptive array antenna.

  By the way, as a promising technology of the next generation mobile communication (4th generation mobile communication) of the third generation mobile communication (W-CDMA and cdma2000) that is currently being put into practical use, research on a multicarrier transmission system is being advanced. ing. The multicarrier transmission method is known as a method that is strong against multipath signals that cause signal characteristic degradation in a mobile communication environment. For example, the OFDM method, which is one of the multicarrier transmission methods, is used for digital terrestrial broadcasting and high-speed transmission. Use in a wireless LAN is being studied. Research is also being conducted to apply the above-described adaptive array antenna to multicarrier communications such as OFDM, MC-CDMA, MC-DS-CDMA, and the like.

  Here, a conventional method of calibration of the RF radio circuit at the time of multicarrier signal transmission will be described. In the conventional method, the calibration value in the RF transmission circuit / reception circuit is calculated for each subcarrier, and the calibration value calculated for each subcarrier is reflected in the transmission signal / reception signal of each subcarrier. Thereby, the amplitude / phase deviation between the branches of the RF transmission circuit / reception circuit is corrected.

In addition, in the calibration of the adaptive array antenna, even if the cross-correlation between the transmission signals of each antenna branch is strong, by inputting the transmission signal from which the cross-correlation between the transmission signals is removed to the amplitude phase adjustment unit, A technique is disclosed that makes it possible to accurately estimate the weight for amplitude phase adjustment without degrading the convergence performance of the amplitude phase adjustment unit (see, for example, Patent Document 1).
JP 2003-273633 A

  In the above-described conventional calibration of the RF radio circuit during multi-carrier signal transmission, it is necessary to calculate a calibration value for each subcarrier. Therefore, it is necessary to hold the calibration value for each subcarrier, and the required memory capacity Will increase. For this reason, there has been a problem that an attempt to realize a highly accurate calibration increases the hardware scale and enlarges the apparatus.

  The present invention has been made in view of the above problems, and an object thereof is to provide an array antenna transmission apparatus, a reception apparatus, and a calibration method in which a highly accurate calibration is realized and the apparatus configuration is simplified. And

  In order to solve the above-described problems, the present invention provides, as described in claim 1, an array antenna transmission apparatus including an array antenna composed of a plurality of antenna elements, wherein the transmission signal has a plurality of bandwidths. A block dividing means for dividing the block, a first transmission calibration value calculating means for calculating a calibration value common to the transmission signals in the block by averaging the transmission signals in the divided blocks; Correction means for correcting an amplitude deviation and a phase deviation generated between branches of a transmission circuit provided corresponding to each of the plurality of antenna elements based on the calculated common calibration value. It is a feature.

  According to claim 2 of the present invention, in the array antenna transmission apparatus, the transmission signal is a multicarrier signal, and the first transmission calibration value calculation means includes an amplitude deviation and a phase deviation for each subcarrier. Is averaged by a plurality of subcarriers in the divided block, thereby calculating a common calibration value for a plurality of subcarriers in the block.

  According to claim 3 of the present invention, in the array antenna transmission apparatus, the amplitude deviation and phase deviation of an arbitrary subcarrier in the block divided by the block dividing means are used, and a plurality of subcarriers in the block are used. A second transmission calibration value calculating means for calculating a calibration value common to the carrier is provided.

  According to a fourth aspect of the present invention, in the array antenna transmission apparatus, the block dividing means determines a block unit based on an amplitude deviation and a phase deviation for each subcarrier.

  In order to solve the above-mentioned problem, the present invention provides an array antenna receiving apparatus having an array antenna composed of a plurality of antenna elements, as described in claim 5. A block dividing means for dividing the block into a plurality of blocks and a first calibration unit that calculates a common calibration value for the received signal in the block by averaging with the received signal in the divided block using a known reference signal Based on the received calibration value calculation means and the calculated common calibration value, the amplitude deviation and phase deviation generated between the branches of the receiving circuit provided corresponding to each of the plurality of antenna elements are corrected. And a correcting means.

  According to claim 6 of the present invention, in the array antenna receiving apparatus, the received signal is a multicarrier signal, and the first reception calibration value calculating means includes an amplitude deviation and a phase deviation for each subcarrier. Is averaged with a plurality of subcarriers in the divided block using a known reference signal to calculate a calibration value common to the plurality of subcarriers in the block.

  According to claim 7 of the present invention, in the array antenna receiving apparatus, the amplitude deviation and the phase deviation in arbitrary subcarriers in the block divided by the block dividing means are used, and a plurality of pieces in the block are used. A second reception calibration value calculation means for obtaining a calibration value common to the subcarriers is provided.

  According to an eighth aspect of the present invention, in the array antenna receiving apparatus, the block dividing means determines a block unit based on an amplitude deviation and a phase deviation for each subcarrier.

  According to a ninth aspect of the present invention, the array antenna receiving apparatus further comprises reference signal generation control means for generating the reference signal used at the time of obtaining the common calibration value at a predetermined timing. It is said.

  According to the present invention, the bandwidth of a multi-carrier signal is divided into a plurality of blocks, and the transmission circuit and reception circuit calibration values common to the plurality of subcarriers present in the divided blocks are calculated and calculated. Calibration accuracy can be improved by performing calibration on the transmission signal and reception signal of each subcarrier in the block based on the common calibration value.

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

  FIG. 1 is a block diagram showing a configuration example of an array antenna transmission apparatus 1 according to an embodiment of the present invention. FIG. 1 shows a configuration of an array antenna (example: adaptive array antenna) transmission apparatus using B (# 1 to #B) antenna elements as an example. Moreover, in the array antenna transmission apparatus 1 in this embodiment, a multicarrier transmission system, for example, an OFDM transmission system, is applied, and description will be made below.

  The array antenna transmission apparatus 1 shown in FIG. 1 includes B antenna elements 11-1 to 11-B and duplexers 12-1 to 12-B provided corresponding to the antenna elements 11-1 to 11-B. RF transmission units (transmission circuits) 13-1 to 13-B, inverse fast Fourier transform units (IFFT (Inverse Fast Fourier Transform)) 14-1 to 14-B, measurement branch selector switch A15, and calibration Value multipliers 16-1 to 16 -B, measurement branch selector switch B 17, calibration RF receiver (receiver circuit) 18, fast Fourier transform unit (FFT (Fast Fourier Transform)) 19, and calibration value And a measuring unit 20.

  The baseband transmission signal (after transmission weight multiplication) of each subcarrier input to the array antenna transmission apparatus 1 is subjected to inverse Fourier transform in the inverse fast Fourier transform units 14-1 to 14-B, and the RF transmission unit 13-1. To 13-B. The transmission signals input to the RF transmitters 13-1 to 13-B are subjected to processing such as filtering and frequency conversion to the RF band, and the duplexers 12-1 to 12-B and the antennas 11-1 to 11-B. To the antennas (# 1 to #B) 11-1 to 11-B.

  RF band transmission signals (hereinafter referred to as RF transmission signals) branched by the duplexers 12-1 to 12-B are distributed in a small proportion immediately before the antenna elements 11-1 to 11-B, and the measurement branch is switched. The switch is switched for each measurement branch by the switch B17, and the RF transmission signal for each branch is input to the calibration RF receiving unit 18.

  The calibration RF receiving unit 18 performs processing such as filtering and frequency conversion to the baseband on the received RF transmission signal and outputs the processed signal to the fast Fourier transform unit 19. Then, the fast Fourier transform unit 19 performs a fast Fourier transform process on the input signal, thereby obtaining a reception signal for each subcarrier. The reception signal for each subcarrier obtained in this way is input to the calibration value measuring unit 20.

  The calibration value measuring unit 20 divides the bandwidth of the multicarrier signal into a plurality of blocks, and averages the amplitude deviation and the phase deviation for each subcarrier with the plurality of subcarriers in the divided block. And a function for obtaining a calibration value common to a plurality of subcarriers in a block. The block division function will be described later. Therefore, here, the description will be made assuming that the data is divided into predetermined block units.

  The calibration value measurement unit 20 performs each block (subcarrier) after each Fourier transform on each transmission subband before each inverse carrier wave and each transmission baseband signal of each branch that are output after being switched by the measurement branch changeover switch A15. A calibration value for each branch / transmission output is calculated, and the result is output to the calibration value multipliers 16-1 to 16-B. That is, the calibration value measurement unit 20 detects the amplitude / phase deviation between the antenna branches by comparing the transmission baseband signals for each subcarrier before and after passing through the RF transmission units 13-1 to 13-B. Based on the result, a calibration value for the transmission signal of each subcarrier in the block is calculated.

  The calibration values at each branch, each block (subcarrier), and each transmission output calculated as described above are the values of each subcarrier before inverse Fourier transform in the calibration value multipliers 16-1 to 16-B. Multiply by the transmitted baseband signal. As a result, the amplitude / phase deviation of the transmission signal of each subcarrier in the block is corrected.

  Next, a specific method for calculating the calibration value in the calibration value measuring unit 20 will be described.

(Calculation method 1)
The calibration value measuring unit 20 divides the entire frequency bandwidth into a plurality of blocks and calculates a calibration value common to a plurality of subcarriers in the divided band when obtaining a calibration value at the time of multicarrier signal transmission. .

  Specifically, the value obtained by multiplying the baseband reception signal of each subcarrier subjected to the fast Fourier transform by the fast Fourier transform unit 19 by the complex conjugate of the transmission signal of each subcarrier before being frequency converted to the RF band. The average calibration value for each subcarrier obtained by performing the in-phase addition averaging for a long time is further averaged within the block, thereby calculating a common calibration value within the block.

For example, after the transmission signal of the branch b (b = 1, 2,..., B) after passing through the downlink RF transmission unit is distributed by the duplexers 12-1 to 12-B, the calibration RF reception unit 18 is The baseband received signal of the j-th sample of the subcarrier s (s = 1, 2,..., N _sub ) that has passed through and subjected to the fast Fourier transform is represented by u _{b, s} (j), and the RF transmitters 13-1 to 13-1 Assuming that the transmission signal before passing through 13-B and before the inverse fast Fourier transform is r _{b, s} (j), the calibration value C _{b, of} block d (d = 1, 2,..., N _blk ) _d is calculated according to the following formula (1).

ここで、ｋは定数、Ｎ_ｃａｌは平均化サンプル数を表す。

Here, k is a constant, and N _cal is the number of averaged samples.

  As described above, according to the present calculation method 1, the calibration value of the block is obtained using a value obtained by averaging the amplitude / phase deviation for each subcarrier among all the subcarriers in the block. At this time, using the fact that the frequency response deviation between adjacent subcarriers is small, averaging is performed between adjacent subcarriers in the block, so that a highly accurate calibration value can be obtained. Accuracy can be improved.

(Calculation method 2)
The calibration value measuring unit 20 receives one subcarrier selected for each block from the baseband received signal of each subcarrier after passing through the calibration RF receiving unit 18 and subjected to fast Fourier transform. The signal is multiplied by the complex conjugate of the signal on the subcarrier selected in the block among the transmission signals of each subcarrier before the downlink inverse fast Fourier transform, and long-term in-phase addition averaging is performed. The calibration value obtained by this is calculated as a common calibration value in the block.

For example, the transmission signal of the branch b (b = 1, 2,..., B) after passing through the downlink RF transmission units 13-1 to 13-B is distributed by the duplexers 12-1 to 12-B and then calibrated. The baseband received signal of the j-th sample of the subcarrier s (s = 1, 2,..., N _sub ) after passing through the fast RF receiving unit 18 and subjected to the fast Fourier transform, u _{b, s} (j), Assuming that the transmission signal before inverse fast Fourier transform is r _{b, s} (j), the calibration value C _{b, d} of the block d (d = 1, 2,..., N _blk ) is expressed by the following equation (2). Is calculated according to

ここで、ｋは定数、Ｎ_ｃａｌは平均化サンプル数を表す。

Here, k is a constant, and N _cal is the number of averaged samples.

  Also, the above equation (2) shows the calibration result when the central subcarrier in the block is selected as a certain subcarrier in each block. Here, since the amplitude / phase variation of the subcarrier due to the frequency in the block is considered to vary approximately linearly, in the example of the above formula (2), the central subcarrier in the block is set to a certain subcarrier. Selected as a carrier.

  As described above, according to the present calculation method 2, the calibration value of the block is obtained by using the amplitude / phase deviation of a certain subcarrier in the block. There exists an effect which can simplify the circuit structure of an antenna transmitter.

  FIG. 2 is a block diagram showing a calibration configuration of the array antenna receiving apparatus 2 according to the embodiment of the present invention. Elements that are used in common with the components in the array antenna transmission apparatus shown in FIG. 1 are given the same reference numerals.

  In the figure, the array antenna receiving apparatus 2 includes B antenna elements 11-1 to 11-B, duplexers 12-1 to 12-B provided corresponding to the antenna elements, and an RF receiving unit 31. -1 to 31-B, measurement branch changeover switch A32, calibration value multiplication units 33-1 to 33-B, measurement branch changeover switch B34, gain adjustment unit 35, and calibration RF transmission unit 36 , A calibration value measuring unit 37 and a calibration reference signal generator 38.

  The calibration reference signal (baseband signal) of each subcarrier and each branch generated by the calibration reference signal generator 38 is input to the calibration value measurement unit 37 and the calibration RF transmission unit 36, respectively. The As the calibration reference signal, for example, it is desirable to use a signal having a spectrum equivalent to the reception signal actually received by the RF reception units 31-1 to 31-B.

  The calibration reference signal is converted into orthogonal subcarriers by inverse fast Fourier transform (not shown), and then input to the calibration RF transmission unit 36 where filtering, frequency conversion to the RF band, etc. Are processed and converted into an RF transmission signal. Thereafter, gain adjustment is performed by the gain adjustment unit 35, and the transmission output from each branch is distributed by the duplexers 12-1 to 12-B and input to the RF reception units 31-1 to 31-B. Thereafter, fast Fourier transform (not shown) is performed to obtain a reception baseband signal for each subcarrier, and the output is switched for each measurement branch by the measurement branch switch A 32 and input to the calibration value measurement unit 37.

  The calibration value measurement unit 37 has a function of dividing the bandwidth of the multicarrier signal into a plurality of blocks, and a plurality of sub-carriers in the block obtained by dividing the amplitude deviation and phase deviation for each subcarrier using a known reference signal. A function of obtaining a calibration value common to a plurality of subcarriers in a block by averaging with carriers is provided. The block division function will be described later. Therefore, here, the description will be made assuming that the data is divided into predetermined block units.

  The calibration value measuring unit 37 receives the calibration reference signal for each subcarrier and each branch converted from the RF band to the baseband band, and each branch for the calibration reference signal for each subcarrier and each branch. Calibration values for each block (subcarrier), each branch, and each received output after passing through the RF receiving units 31-1 to 31-B of the RF receiving units 31-1 to 31-B, and the results are calculated as calibration value multiplying units 33-1 to 33-B. Output to. That is, the calibration value measuring unit 37 detects the amplitude / phase deviation between the antenna branches by comparing the calibration reference signals before and after passing through the RF receiving units 31-1 to 31 -B, and based on the result. Then, a calibration value for the received signal of each subcarrier in the block is calculated.

  The calibration value in each branch and each block (subcarrier) calculated as described above is the transmission baseband signal of each subcarrier after the fast Fourier transform in the calibration value multipliers 33-1 to 33-B. And multiplied. As a result, the amplitude / phase deviation of the received signal of each subcarrier in the block is corrected.

  Here, the generation reference of the calibration reference signal generated by the calibration reference signal generator 38 will be described. For example, the following method can be considered as a reference for generating the calibration reference signal.

  (Method 1) Always introduced into the RF receiver and calibrated. According to the method 1, since calibration is always performed, there is no burden of control processing necessary for calibration. For this reason, an apparatus structure can be simplified.

(Method 2) a reference signal for calibration is introduced between the _{T 1 (T 1 <T 0} ) in every predetermined time _{T o,} perform calibration. During system operation, the RF receiver receives both the RF band calibration reference signal and the user radio signal received via the antenna, so the calibration reference signal interferes with the user signal. It may become. In Method 2, in order to suppress the influence of such interference as much as possible, the generation of the calibration reference signal is controlled by time. As a result, it is possible to perform calibration while minimizing the interference caused by the user signal during calibration.

(Method 3) advance constantly monitors the temperature of the RF receiver in the sensor, the temperature when performing the last calibration, when ΔT changes, the reference signal for calibration is introduced between the T _1, calibration I do. The amplitude / phase deviation in the RF receiver is strongly influenced by temperature fluctuations. In the method 3, such temperature fluctuation is detected, and a calibration reference signal is generated only when there is a predetermined temperature fluctuation. As a result, it is possible to accurately and efficiently compensate for the amplitude / phase deviation caused by the temperature fluctuation.

  Next, a calibration value calculation method in the calibration value measurement unit will be described.

(Calculation method 1)
In the present embodiment, the calibration value measurement unit 37 divides the entire frequency bandwidth into a plurality of blocks when obtaining the calibration value at the time of multicarrier signal transmission, as in the case of the array antenna transmission device 1 described above. A calibration value common to a plurality of subcarriers in the divided band is calculated.

  Specifically, each subcarrier received signal after passing through the RF receivers 31-1 to 31 -B and subjected to the fast Fourier transform is multiplied by the complex conjugate of the calibration reference signal signal of each subcarrier. A common calibration value is calculated in the block by further averaging the calibration values for each subcarrier obtained by performing the in-phase addition averaging for a long time.

For example, the subcarrier s (s = 1) in the branch b (b = 1, 2,..., B) after passing through the RF receiving units 31-1 to 31-B in the RF receiving units 31-1 to 31-B. , 2,..., N _sub ) j-th baseband received signal (combination of uplink actual received signal and calibration reference signal) u _{b, s} (j), calibration reference signal Is r _{b, s} (j), the calibration value C _{b, d} of the block d (d = 1, 2,..., N _blk ) can be calculated in the same manner as the above equation (1). it can.

According to this calculation method 1, the same effect as the calibration in the array antenna transmission apparatus 1 described above can be obtained.
(Calculation method 2)
The calibration value measuring unit 37 passes through the RF receiving units 31-1 to 31 -B, and among the received subcarrier signals after fast Fourier transform, the received signal of one subcarrier selected in each block On the other hand, a calibration value obtained by performing in-phase addition averaging for a long time on a value obtained by multiplying the complex conjugate of the calibration reference signal of the same subcarrier is calculated as a common calibration value in the block. The subcarrier s (s = 1, 2) in the branch b (b = 1, 2,..., B) after passing through the RF receiving units 31-1 to 31-B in the RF receiving units 31-1 to 31-B. ,..., N _sub ) j-th baseband received signal (combination of uplink actual received signal and calibration reference signal) u _{b, s} (j), and calibration reference signal r _{Assuming b, s} (j), the calibration values C _{b, d} of the block d (d = 1, 2,..., N _blk ) can be calculated in the same manner as the above equation (2).

According to this calculation method 2, the same effect as the calibration in the array antenna transmission apparatus described above can be obtained.
As described above, in the present embodiment, the overall bandwidth of a multicarrier signal is divided into a plurality of blocks, and the calibration value of the array antenna transmission / reception apparatus common to a plurality of subcarriers existing in the divided band is obtained. Is calculated.

  Next, the block division method (block size determination method) will be described with reference to FIG. FIGS. 3A to 3C show block size determination methods 1 to 3. FIG.

The block size determination method 1 is a method of _equally dividing all subcarriers into N _blk blocks as shown in FIG. This method does not change the block size even when the calibration value is updated.

As shown in FIG. 2B, the block size determination method 2 measures the amplitude / phase fluctuation amount in each subcarrier when an array antenna transmission / reception apparatus is installed, The number of subcarriers in each block is divided into N _blk so that the amplitude / phase deviation is equal to or smaller than ΔAmp and ΔPhase (parameters) (the number of subcarriers in each block is not necessarily the same). Also, the number of subcarriers in each block is not changed when the calibration value is updated.

As shown in FIG. 3C, the block size determination method 3 measures the amplitude / phase fluctuation amount in each subcarrier when the array antenna transmission / reception apparatus is installed, and determines the subcarriers in the block. The number of subcarriers in each block is divided into N _blk so that the amplitude / phase deviation of A is less than ΔAmp and ΔPhase (parameters) (the number of subcarriers in each block is not necessarily the same). When updating the calibration value, the amplitude / phase deviation between the subcarriers in the block is less than ΔAmp and ΔPhase (parameters) based on the amplitude / phase fluctuation amount in each subcarrier. Thus, the number of subcarriers in each block is adaptively changed.

  In this way, by changing the number of subcarriers (block size) in each block according to the amplitude / phase deviation between subcarriers in the block, the array antenna transmission / reception device due to secular change or temperature change Can be accurately calibrated.

  In the above embodiment, the calibration method including the duplexers 12-1 to 12-B has been described as one aspect. However, the present invention is not limited to such an aspect. For example, the calibration may be performed by directly inputting the transmission output of the RF transmitters 13-1 to 13 -B to the calibration RF receiver 18 without going through the duplexers 12-1 to 12 -B. Calibration may be performed by directly inputting the transmission output from the RF transmitter for transmission 36 to the RF receivers 31-1 to 31 -B. In this case, there is an advantage that it is not necessary to consider the influence (passage loss etc.) of the duplexers 12-1 to 12-B when obtaining the calibration value.

  In the above embodiment, a transmission / reception apparatus that performs multicarrier signal transmission has been described. However, the present invention is a transmission / reception apparatus that uses a single carrier transmission scheme, for example, third-generation mobility such as W-CDMA. The present invention can also be applied to a communication system.

  Further, in the above embodiment, the function of the calibration value measurement unit 20 in the array antenna transmission apparatus 1 includes the calibration value in the block division unit, the first transmission calibration value calculation unit, and the second transmission calibration value calculation unit. The functions of the multiplication units 16-1 to 16-B correspond to correction means. The function of the calibration value measuring unit 37 in the array antenna receiving apparatus 2 is the same as the block dividing unit, the first received calibration value calculating unit, and the second received calibration value calculating unit. The function of .about.33-B corresponds to the correction means. The function of the calibration reference signal generator 38 corresponds to the reference signal generation control means.

It is a block diagram which shows the structural example of the array antenna transmission apparatus in embodiment of this invention. It is a block diagram which shows the structural example of the array antenna receiver in embodiment of this invention. It is a figure for demonstrating the determination method of block size (the number of subcarriers for every block). It is a block diagram which shows the structure of the conventional RF radio | wireless transmitter circuit using an adaptive array antenna. It is a block diagram which shows the structural example of the conventional RF radio | wireless receiving circuit using an adaptive array antenna.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Array antenna transmitter 2 Array antenna receiver 11-1 to 11-B, 101-1 to 101-B Antenna element 12-1 to 12-B Duplexer 13-1 to 13-B RF transmitter 14-1 to 14 -B Inverse Fast Fourier Transform (IFFT)
15 Measurement branch selector switch A
16-1 to 16-B Calibration value multiplication unit 17 Measurement branch selector switch B
18 RF receiver for calibration 19 Fast Fourier transform (FFT)
20, 37 Calibration value measuring unit 31-1 to 31-B RF receiving unit
32 Measurement branch selector switch A
33-1 to 33-B Calibration value multiplier 34 Measurement branch selector switch B
35 Gain adjuster 36 Calibration RF transmitter 38 Calibration reference signal generator 102 Digital / analog signal conversion processor 103 Orthogonal modulator 104, 203 Mixer (multiplier)
105 High-power amplifier 202 Low-noise amplifier 204 Band-limited pass filter 205 Automatic gain controller (AGC circuit)
206 Quadrature detection unit 207 Reception level measurement unit 208 Analog / digital signal conversion processing unit

Claims (10)

In an array antenna transmission apparatus comprising an array antenna composed of a plurality of antenna elements,
Block dividing means for dividing the bandwidth of the transmission signal into a plurality of blocks;
A first transmission calibration value calculating means for calculating a calibration value common to the transmission signals in the block by averaging the transmission signals in the divided blocks;
Based on the calculated common calibration value, correction means for correcting amplitude deviation and phase deviation generated between branches of the transmission circuit provided corresponding to each of the plurality of antenna elements;
An array antenna transmission apparatus comprising: The array antenna transmission apparatus according to claim 1,
The transmission signal is a multi-carrier signal;
The first transmission calibration value calculation means averages the amplitude deviation and phase deviation for each subcarrier among the plurality of subcarriers in the divided block, thereby common to the plurality of subcarriers in the block. An array antenna transmitter characterized by calculating a calibration value. The array antenna transmission apparatus according to claim 2,
Second transmission calibration value calculation means for calculating a calibration value common to a plurality of subcarriers in the block using amplitude deviation and phase deviation of arbitrary subcarriers in the block divided by the block division means An array antenna transmission apparatus comprising: The array antenna transmission apparatus according to claim 2 or 3,
The array antenna transmitting apparatus according to claim 1, wherein the block dividing means determines a block unit based on an amplitude deviation and a phase deviation for each subcarrier. In an array antenna receiving apparatus comprising an array antenna composed of a plurality of antenna elements,
Block dividing means for dividing the bandwidth of the received signal into a plurality of blocks;
A first received calibration value calculating means for calculating a common calibration value for the received signals in the block by averaging the received signals in the divided block using a known reference signal;
Based on the calculated common calibration value, correction means for correcting an amplitude deviation and a phase deviation that occur between branches of the receiving circuit provided corresponding to each of the plurality of antenna elements;
An array antenna receiving apparatus comprising: The array antenna receiver according to claim 5,
The received signal is a multi-carrier signal;
The first reception calibration value calculation means averages the amplitude deviation and phase deviation for each subcarrier with a plurality of subcarriers in the divided block by using a known reference signal, and An array antenna receiving apparatus that calculates a calibration value common to a plurality of subcarriers. In the array antenna receiver according to claim 6,
Second received calibration value calculation means for obtaining a calibration value common to a plurality of subcarriers in the block by using amplitude deviation and phase deviation in arbitrary subcarriers in the block divided by the block dividing means. An array antenna receiving apparatus comprising: In the array antenna receiver according to claim 6 or 7,
The array antenna receiving apparatus according to claim 1, wherein the block dividing means determines a block unit based on an amplitude deviation and a phase deviation for each subcarrier. The array antenna receiving apparatus according to any one of claims 5 to 8,
An array antenna receiving apparatus, comprising: reference signal generation control means for generating the reference signal used for obtaining the common calibration value at a predetermined timing. A method for calibrating a radio circuit in an array antenna radio communication device comprising an array antenna composed of a plurality of antenna elements,
Divide the bandwidth of the radio signal into multiple blocks,
By averaging the radio signals in the divided blocks, a common calibration value is calculated for the radio signals in the block,
A calibration method comprising correcting an amplitude deviation and a phase deviation generated between the branches of the radio circuit based on the calculated calibration value.

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