HK1070195B - Array antenna communication apparatus - Google Patents

Description

Array antenna communication device

Technical Field

The present invention relates to a communication apparatus that controls a transmitting/receiving antenna pattern (pattern) by using a plurality of antennas.

Background

A communication device including an adaptive array antenna which forms a reception antenna/pattern having a combined pattern in the direction of arrival of a desired wave and a pattern in the direction of arrival of an interference wave by appropriately adding and combining signals received by a plurality of antennas which are spatially arranged at intervals and selectively receive the desired signal is known. When transmission is performed by the communication apparatus, it is preferable to form a transmission antenna/pattern having a pattern in the direction of the desired station and a pattern in the direction of the interfering station. Accordingly, it is effective in that the communication is performed independently in the group of the own communication apparatus and the subscriber station, and the interference is not easily affected by the own communication apparatus, because the directional pattern is formed in the subscriber station direction, the transmission power can be selectively steered to the subscriber station direction, and the directional pattern is directed to the interference station direction.

Here, a communication apparatus including a conventional adaptive array antenna will be described with reference to fig. 9. Here, as an example, a case will be described where an adaptive array antenna is used in which transmission/reception communication is performed with the same transmission/reception frequency and time-division is performed, and 4 antennas 52 are arranged spatially apart from each other.

First, the processing at the time of reception will be described. A signal received by the antenna 52 is amplified by a Low Noise Amplifier (LNA)56 via a transmission/reception converter 54 (a connection state at the time of reception is shown in fig. 9) for converting transmission/reception, and then input to a mixer 58, where it is converted into an Intermediate Frequency (IF) by crossing a local oscillation frequency from a local transmitter 60. Next, the signal is selected by the IF filter 62 to receive only a frequency signal near the frequency, amplified by the IF amplifier 64, input to the mixer 66, mixed with the local oscillation frequency from the local transmitter 68, and converted into a baseband signal. Then, the signal is identified as a necessary bandwidth by the low-pass filter 70, and converted into a digital signal by the sampling processing unit (a/D) 72. The received signals in the 4 antennas 52 are each thus converted into a baseband signal. These signals are input to the reception-side processing section 74, where characteristic weighting (coefficients: w1 to w4) is performed in accordance with the amplitude and phase, and thereafter, the signals are added and processed as reception signals. Although the signals received by the antenna include not only the desired station signal but also the interfering station signal, the adaptive antenna processing unit 76 can remove the interfering station signal from the received signal and receive only the desired station signal by appropriately determining the weighting coefficient (reception weighting value) based on the reference signal and the received signal. This process is described in detail in the document "adaptive signal processing using array antenna" of the first edition, scientific and technical publication of japan, 1998, month 11.

Next, a process at the time of transmission will be described. The transmission-side processing unit 78 divides the input transmission signal into 4 pieces and performs weighting for each piece. Here, as the weight value at the time of transmission, a weight value at the time of reception may be used. This is because a transmission antenna pattern having the same pattern and directional pattern as a reception antenna pattern is formed by utilizing the inverse of the transmission signal and the reception signal. The divided and weighted signals are input to a mixer 84 via a digital-analog converter (D/a)80 and a low-pass filter 82, and are converted to an IF frequency by mixing using a local frequency. The signal is filtered by an IF filter 86, amplified by an IF amplifier 88, and input to a mixer 90, where it is converted to an RF frequency by mixing using a local oscillation frequency. Subsequently, the signal is transmitted from the antenna 52 via a transmission Power Amplifier (PA)92 and a transmission/reception converter 54.

However, in the above-described conventional technique, the weight value at the time of transmission and the weight value at the time of reception are made the same. Although this is done according to the inverse of the spatial signal after the antenna 52, in the case of a radio section, since the transmission section (TX) through which the transmission signal passes and the reception section (RX) through which the reception signal passes are different, the inverse does not hold. Therefore, as in the conventional technique described above, even if the same weight value as that used in the reception-side processing unit 74 is used in the transmission-side processing unit 78, the same transmission directivity as that in the reception cannot be obtained. That is, since the phase rotation amount and amplitude variation amount of the transmission signal passing through TX are different from those of the reception signal passing through RX, even if the same weighting is applied during transmission and reception, the signal amplitude and phase when the transmission signal passes through TX and reaches the antenna are different from those when the reception signal is received. That is, if the same weighting is applied during transmission and reception, the transmission antenna pattern and the reception antenna pattern are different from each other, and the pattern directivity of the reception signal are different from each other at the time of transmission.

Therefore, in the communication apparatus including such an adaptive array antenna, it is necessary to perform appropriate adjustment so that the amount of phase rotation of the transmission signal in the transmission unit (TX) is equal to the amount of phase rotation of the reception signal in the reception unit (RX) and the amount of amplitude change of the transmission signal in the transmission unit (TX) is equal to the amount of amplitude change of the reception signal in the reception unit (RX) and a fixed magnification common to the respective antennas for each of the 4 systems.

In this case, adjustment (receiver calibration) is usually performed for all the receiving units (RX) of 4 systems so that the amplitude variation and the phase rotation amount become fixed values, and adjustment (transmitter calibration) is performed for all the transmitting units (TX) of 4 systems so that the amplitude variation and the phase rotation amount become fixed values. This adjustment is performed by the amplitude/phase correction unit 94 provided in the reception-side processing unit 74 for each system (each reception unit) and by the amplitude/phase correction unit 96 provided in the transmission-side processing unit 78 for each system (each transmission unit). Specifically, as described in japanese patent No. 3332911 and japanese patent application laid-open No. 2003-501971, the calibration (calibration) is performed by switching to the receiving side or the transmitting side in each system to sequentially measure the amplitude and phase of the received signal when it passes through the receiving section (RX) and the amplitude and phase of the transmitted signal when it passes through the transmitting section (TX).

However, according to the methods described in japanese patent No. 3332911 and japanese patent application laid-open No. 2003-501971, since the respective orders of a plurality of systems are converted into transmission and reception to measure the amplitude and phase of the passing time in turn, there is a problem that it takes time until the calibration is completed. Further, there is a problem that it is difficult to perform calibration with high accuracy because amplitude change and phase rotation are newly generated in the process of performing calibration. In addition, it is generally extremely difficult to keep the transmitting unit and the receiving unit in a state where there is no characteristic change during the calibration, and as a countermeasure therefor, it is often necessary to perform a calibration which is extremely troublesome as described in japanese patent application laid-open No. 2001-53663 and in which normal calibration is always performed in parallel at the time of operation to continue such calibration.

In addition, since the signal levels from the desired station and the interfering station vary greatly depending on the distance to the desired station and the interfering station, an automatic gain control device (AGC) is usually provided in the receiving unit, but since the AGC is provided, there are cases where the amplitude variation amount and the phase rotation amount differ from each other in the receiving unit according to the variation in the reception level, and there are many cases where calibration correction values which are intentionally made cannot be effectively used in practice.

Further, when some abnormality occurs in the amplitude/phase correction unit on the receiving side, and normal correction cannot be performed, an error caused by the abnormality is added to the weight value of the processing unit on the receiving side. Further, since the weighted value added with the error is further used for the transmission side, there is a problem that the transmission antenna pattern and the reception antenna pattern are significantly different from each other.

Therefore, the inventors have invented an array antenna communication device which has not been found in the past, and so-called japanese patent application 2003-49556 is intended to solve the above-mentioned problems. The array antenna communication device is a communication device using an adaptive array antenna including a plurality of unit antennas, and includes: an RF transmission system circuit provided for each of the unit antennas and including at least a transmission power amplifier; an RF reception system circuit provided in parallel with the RF transmission system circuit for each unit antenna and including at least a low noise power amplifier; a bidirectional vector modulator connected to the RF transmitting circuit and the RF receiving circuit on the other side of the unit antenna; an allocation combining unit connected to the plurality of bidirectional vector modulation units; a transmission/reception unit (TRX) connected to the distribution/synthesis unit; and an adaptive processing unit for controlling the bidirectional vector modulator to cause the plurality of unit antennas to function as adaptive array antennas, wherein the difference between the amplitude change amounts and the difference between the phase rotation amounts of the signals passing through the unit antennas are made substantially equal between the unit antennas for the RF transmission system circuit and the RF reception system circuit corresponding to the unit antennas.

The array antenna communication device shares signal paths as much as possible during transmission/reception, and realizes adaptive operation based on the same parameters during transmission/reception. With this configuration, a significant effect is obtained that the difference between the antenna patterns between transmission and reception can be reduced more easily and more accurately.

The array antenna communication device will be described in more detail with reference to fig. 8. Fig. 8 is a block diagram showing an example of a main part of the array antenna communication device 10 a. Here, an example in which an adaptive array antenna is configured by using 4 antennas (unit antennas) 12 will be described.

The signal inputted to each antenna 12 is inputted to a bidirectional vector modulator 22 via a bandpass filter (BPF)16 and a Low Noise Amplifier (LNA)18 in a state where the transmission/reception converters 14 and 20 are connected to the receiving side, and further via the transmission/reception converter 20. Here, between the transmission/reception converter 14 and the transmission/reception converter 20, there are circuits (that is, an RF transmission system circuit and an RF reception system circuit) independent of each other in accordance with the transmission system and the reception system, and these are referred to as an unshared circuit section 24. Then, the plurality of system signals weighted by the bidirectional vector modulator 22 are added by the distribution/synthesis unit 26 and received (received signal) by the transmission/reception unit (TRX) 28. A part of the received signal is input to an Adaptive Processing Unit (APU) 30.

The signal output from the Low Noise Amplifier (LNA)18 is input to the adaptive processing unit 30 via a receiving unit (RX)32 provided in each system.

The adaptive processing unit 30 obtains a weight (weight in each bidirectional vector modulator 22) necessary for extracting a desired wave signal by separating interference waves, noise, and the like based on the input reference signal and the signal from the TRX28, and sets the weight in each bidirectional vector modulator 22. Thus, a reception antenna/pattern having a pattern in the direction of the useful station and a pattern in the direction of the interfering station can be formed. In addition, the SN ratio of the signal from the desired station can be improved.

On the other hand, the baseband transmission signal is distributed to each system by the distribution/synthesis unit 26 via the transmission/reception unit (TRX) 28. The distributed signals are input to the bidirectional vector modulator 22, passed through the transmission/reception converter 20 and the adjuster (mainly functioning as a phase adjuster, but may also function as an amplitude adjuster) 34, amplified in power by the transmission Power Amplifier (PA), and then output from the antenna 12 through the transmission/reception converter 14. Both the transmission/reception converters 14 and 20 are connected to the transmission side at the time of transmission.

In this configuration, the signal paths are different between the transmission/reception converters 14 and 20 in the RF band according to transmission/reception, that is, the unshared circuit section 24. However, the regulator 34 is provided in the unshared circuit unit 24, and the configuration (or regulation) of each system is such that the difference between the amplitude change amounts and the difference between the phase rotation amounts become almost the same value between the antennas (unit antennas) 12 in the transmission path (RF transmission system circuit) and the reception path (RF reception system circuit), respectively, and no problem occurs due to the difference therebetween.

The weight value for each system is a value for the bi-directional vector modulator 22 which is common to the transmission/reception processes. Therefore, according to the array antenna communication device 10a, by doubling the change in the signal characteristics in the transmission path and the reception path by the adjuster 34 in each system, it is possible to form the transmission antenna pattern and the reception antenna pattern as the same pattern (that is, antennas having the same pattern and pattern) using a weight value common in the transmission/reception process for each system.

The unshared circuit unit 24 is preferably configured to further equalize the elapsed delay times in the transmission system and the reception system (or to have an adjustable component). This is based on the definition of such group delay times that are equal in frequency dependence of the passing phase between circuits with equal delay times (more in detail group delay times). That is, if the phase difference between the transmission system and the reception system is fixed at a certain frequency, it is intended to prevent the phase difference from occurring at another frequency according to the fixed value. That is, this configuration is effective particularly for a communication apparatus using a plurality of frequencies because the phase difference between the transmission path and the reception path can be made substantially the same for a wider frequency band.

In the array antenna communication device 10a, it is preferable that the reception system is provided with a device (the adaptive processing unit 30 corresponds to this device in the present embodiment) for detecting and correcting an amplitude difference and a phase difference between a signal input to the adaptive processing unit 30 via the bidirectional vector modulator 22, the distribution/synthesis unit 26, and the TRX28, and a signal distributed from the previous stage (antenna 12 side) of the bidirectional vector modulator 22 and input to the adaptive processing unit via the reception unit (RX)32 of each system.

In fig. 8, a filter is used for selectively receiving a necessary frequency band in the common transceiver unit (TRX)28 and the individual receiver unit (RX)32 corresponding to each unit antenna, and a signal of the necessary frequency band corresponding to an information communication frequency band is finally extracted by the filter. The delay time of this filter depends on the attenuation outside the frequency band, the frequency drop characteristic, and the like, but generally involves at least a delay of several symbols for 1 symbol (symbol) of the signal.

However, the delays of the several symbols are different from filter to filter, and may scatter about several tens% of the absolute delay amount depending on the situation. As a result, there is a possibility that a delay time error of about several symbols may occur between the common transmission/reception unit (TRX)28 and the individual reception unit (RX)32 corresponding to each unit antenna, and there is a problem that the delay difference between the Adaptive Processing Unit (APU)30, which performs analog-to-digital conversion processing at a time interval of 1/2 or 1/4 symbols, is generally large to such an extent that it cannot be ignored.

Disclosure of Invention

An array antenna communication device according to the present invention is an adaptive array antenna including a plurality of unit antennas, and is characterized in that: is provided with

An RF transmission system circuit provided for each of the unit antennas and including at least a transmission power amplifier;

an RF reception system circuit which is provided in parallel with the RF transmission system circuit for each unit antenna and includes at least a low noise amplifier, and in which a difference between an amplitude change amount and a difference between a phase rotation amount when a signal passes through the RF transmission system circuit and the RF reception system circuit for each unit antenna are set to be substantially equal to each other for each unit antenna;

a bidirectional vector modulator connected to the other end of the RF transmitting circuit and the RF receiving circuit connected in parallel to the unit antenna connection end;

a distribution synthesis unit connected to the plurality of bidirectional vector modulators;

a transmission/reception unit (TRX) connected to the distribution/synthesis unit;

a first sampling processing unit for sampling the analog reception signal outputted from the transmission/reception unit;

a Receiver (RX) connected to each of the RF reception system circuits;

a second sampling processing unit connected to each of the receiving units (RX) for sampling the analog reception signals outputted from the receiving units (RX);

a delay time correcting device for correcting a delay time of at least one of the output signal of the first sampling processing unit and the output signal of the second sampling processing unit;

and an adaptive processing unit for controlling the bidirectional vector modulator based on the output signal of the first sampling processing unit and the output signal of the second sampling processing unit corrected by the delay time correcting unit, so that the plurality of unit antennas function as adaptive array antennas, thereby reducing a symbol delay between the transmitting/receiving unit and the receiving unit.

In the array antenna communication device according to the present invention, it is preferable that the delay time correcting means includes means for correcting a sampling timing of at least one of the first sampling processing unit and the second sampling processing unit.

In the array antenna communication device according to the present invention, it is preferable that the delay time correction unit includes a variable shift register.

In the array antenna communication device according to the present invention, it is preferable that the delay time corrector corrects the delay time based on a correlation value between the output signal of the first sampling processor and the output signal of the second sampling processor corrected by the delay time corrector.

Drawings

Fig. 1 shows an example of a circuit configuration of an array antenna communication device according to an embodiment of the present invention.

Fig. 2 shows an example of a circuit configuration of a main part of the array antenna communication apparatus according to the first embodiment of the present invention.

Fig. 3 is an explanatory diagram showing an example of sampling timing control in the array antenna communication device according to the first embodiment of the present invention.

Fig. 4 shows an example of a circuit configuration of a main part of an array antenna communication apparatus according to a second embodiment of the present invention.

Fig. 5 is an explanatory diagram showing an example of sampling timing control in the array antenna communication device according to the second embodiment of the present invention.

Fig. 6 shows an example of an output waveform from a clock generator in the array antenna communication device according to the second embodiment of the present invention.

Fig. 7 shows an example of a circuit configuration of a main part of an array antenna communication apparatus according to a third embodiment of the present invention.

Fig. 8 is a block diagram showing the structure of the array antenna communication apparatus.

Fig. 9 shows a circuit configuration of a conventional communication device.

Detailed Description

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. Fig. 1 is a block diagram showing an example of the configuration of an array antenna communication device 10 according to the present embodiment, and fig. 2 is a block diagram showing the configurations of sampling processing units (a/D)101 and 102, an adaptive processing unit 30, and a sampling timing control unit 103 of the array antenna communication device 10. The array antenna communication device 10 according to the present embodiment includes the same configuration elements as those of the array antenna communication device 10a (fig. 8). Therefore, the same reference numerals are given to the same components, and detailed description of the overlapping parts will be omitted. In the present embodiment, an example in which an adaptive array antenna is configured by using 4 antennas (unit antennas) 12 will be described.

In fig. 1, 101 is a second sampling processing unit (a/D converter, shown as a/D in the figure) that samples a signal of a receiving unit (RX)32 directly connected to a receiving system at a specified sampling timing and converts the sampled signal into a digital signal, 102 is a second sampling processing unit (a/D converter, shown as a/D in the figure) that samples a received signal of a common transmitting/receiving unit 28 at the specified sampling timing and converts the sampled signal into a digital signal, 103 is a sampling timing control unit that controls a mutual time relationship of sampling timings (sampling clock pulses that control the sampling timings) of the sampling processing units (a/D)101, 102, reference signal injection section 104 supplies a common reference signal to the monitoring system circuit of each unit antenna 12 including the reception section (RX)32 and the transmission/reception system circuit including the bidirectional vector modulator 22, the allocation combining section 26, and the transmission/reception section (TRX) 28. The delay time can be corrected based on the reference signal.

In the present embodiment, as shown in fig. 2, the adaptive processing unit 30 includes a correlation integrator 105 and a determination circuit 106, and the sampling timing control unit 103 includes a variable frequency divider 107, a frequency divider 108, and a clock generator 109. The output signals of the sampling processing units (a/D)101 and 102 are subjected to correlation integration by a correlation integrator 105 provided in the adaptive processing unit 30. The output signal of the clock generator 109 is divided by the frequency divider 108 into n times of the frequency, and becomes a sampling clock for determining the sampling timing of the first sampling processing unit (a/D) 102. The output signal of the frequency divider 108 is input to the variable frequency divider 107, and is divided by a frequency (n-1), n, or (n + 1). The output signal of the variable frequency divider 107 is a sampling clock pulse for determining the sampling timing of the second sampling processing unit (a/D) 101.

In this configuration, the individual receiving unit (RX)32 provided for each unit antenna 12 and the transmitting/receiving unit (TRX)28 shared by each of the plurality of unit antennas 12 include an RF filter, an IF filter, a baseband filter, and the like, and have a delay time specific to each of them. That is, each has a filter necessary for selectively receiving a necessary frequency band, and a signal of the necessary frequency band corresponding to the information communication frequency band is finally extracted by the filter. As described above, although the delay time of the filter depends on the attenuation amount outside the frequency band, the frequency drop characteristic, and the like, 1 symbol (symbol) of the signal is generally accompanied by a delay of at least several symbols.

However, the delays of the plurality of symbols are different from filter to filter, and may scatter about several tens% of the absolute delay amount depending on the situation. Therefore, as described above, in a state where any countermeasure is not implemented, there is a possibility that a delay time error of about several symbols may occur between the common transmission/reception unit (TRX)28 and the individual reception unit (RX)32 corresponding to each unit antenna, and in general, the delay difference between the Adaptive Processing Unit (APU)30 that performs analog-to-digital conversion processing at a time interval of 1/2 or 1/4 symbols becomes large to such an extent that it cannot be ignored.

Here, the signal injected from the reference signal injection unit 104 is converted into a digital signal by the sampling processing unit (a/D)101 through the individual reception unit (RX) 32. On the other hand, the signal injected from the reference signal injection unit 104 is converted into a digital signal by the sampling processing unit (a/D)102 via the bidirectional vector modulator 22, the distribution combining unit 26, and the common transmission/reception unit 28. A signal which is converted into a digital signal by a sampling processing unit (A/D)101 and a signal which is converted into a digital signal by a sampling processing unit (A/D)102 are detected as signals which are deviated only from the delay time differences between the individual receiving unit (RX) and the common transmitting/receiving unit (TRX).

Therefore, in the present embodiment, for example, the sampling timing of the second sampling processing unit (a/D)101 is variably controlled by the sampling timing control unit 103, and thus the delay time difference between them has been corrected so as to reduce the error caused by the delay time difference between the receiving unit (RX)32 and the transmitting/receiving unit (TRX)28 between the output signal of the first sampling processing unit (a/D)102 and the output signal of the second sampling processing unit (a/D)101 as much as possible. With this configuration, it is possible to absorb a delay time error equal to or less than the sampling interval of the sampling processing units (a/D)101 and 102, prevent the output signal of the receiving unit 32 used for directivity control of the adaptive array antenna from becoming a signal at a different time (time), and improve the convergence characteristic of control by the adaptive processing unit 30.

Fig. 3 shows an example of the operation of the sampling timing control unit 103 required to perform the delay time correction. As shown in fig. 3, when the variable frequency divider 107 performs adjustment by frequency division (n-1), the sampling clock pulse is output at a timing 1/n faster and the sampling timing of the second sampling processing unit 101 is advanced by 1/n, whereas when the variable frequency divider performs adjustment by frequency division (n +1), the sampling clock pulse is output at a timing 1/n slower and the sampling timing of the second sampling processing unit 101 is slowed by 1/n. The variable frequency divider 107 performs control in accordance with the determination result of the determination circuit 106. When there is no delay time difference between the output signal of the second sampling processing section (a/D)101 and the output signal of the first sampling processing section (a/D)102, the correlation integral value (correlation value) of the output signals is maximized. That is, the determination circuit 106 may control the variable frequency divider 107 to change the sampling timing of the second sampling processing unit (a/D)101 so that the correlation integral value becomes maximum. The variable frequency divider 107 is normally set to divide by n, and is adjusted to divide by (n-1) or (n +1) by 1 or a predetermined number of times by the decision circuit 106. Although fig. 2 shows only a circuit corresponding to one unit antenna 12, it is preferable that this structure is provided together with each antenna 4 system and the above control is performed in each system.

Next, a second embodiment of the present invention will be described with reference to the drawings. Fig. 4 is a block diagram showing the configurations of the sampling processing units (a/D)101 and 102, the adaptive processing unit 30, and the sampling timing control unit 103 of the array antenna communication device 10 according to the present embodiment. The array antenna communication device 10 according to the present embodiment includes the same components as those of the array antenna communication devices 10 (fig. 1) and 10a (fig. 8). Therefore, the same reference numerals are given to the same components, and detailed description of the overlapping parts will be omitted. In the present embodiment, an example in which an adaptive array antenna is configured by using 4 antennas (unit antennas) 12 will be described.

In the present embodiment, the clock pulse generator 113 outputs, for example, a sine wave. The comparator 114 is used to compare the output signal of the clock pulse generator 113 with the reference voltage Vref, and generate a binary input signal. The output signal is a sampling clock of the first sampling processing unit (a/D) 102. That is, in the present embodiment, the sampling frequency of the first sampling processing unit (a/D)102 is also fixed.

On the other hand, the output signal of the clock pulse generator 113 is input to another comparator 116. The comparator 116 receives as a reference voltage an output signal of the determination circuit 106 converted into a digital signal by a D/a converter (D/a) 115. Subsequently, the binary output signal of the comparator 116 becomes a sampling clock pulse of the second sampling processing section (a/D) 101.

Fig. 5 shows an example of the action of the comparator 116. Fig. 5 shows a clock pulse waveform (output signal of the clock pulse generator 113) and a sampling clock pulse waveform in the (a) normal state, (b) higher-than-normal state, and (c) lower-than-normal state of the reference voltage (threshold) as the output signal of the D/a converter (D/a) 115. As can be seen from the drawing, in the present embodiment, the sampling timing is controlled by changing the threshold up and down according to the determination result of the determination circuit 106. Specifically, when the output signal of the second sampling processing unit (a/D)101 is relatively fast, the determination circuit 106 controls to increase the threshold value and delay the sampling clock pulse of the second sampling processing unit (a/D)101 by (b). Conversely, when the output signal of the second sampling processing unit (a/D)101 is relatively slow, the determination circuit 106 controls to decrease the threshold value and advance the sampling clock pulse of the second sampling processing unit (a/D)101 by (c). Although the description has been made with respect to an example in which the clock pulse generator 113 outputs a sine wave in fig. 5, signals of various waveforms may be used instead of the sine wave as shown in fig. 6. In the present embodiment, although only the circuit corresponding to one unit antenna 12 is shown in fig. 4, it is preferable that this configuration is provided together with each antenna 4 system and the control is executed in each system.

Next, a third embodiment of the present invention will be described with reference to the drawings. Fig. 7 is a block diagram showing the configuration of the sampling processing units (a/D)101 and 102, the adaptive processing unit 30a, and the sampling timing control unit 103 of the array antenna communication device 10 according to the present embodiment. The array antenna communication device 10 according to the present embodiment includes the same components as those of the array antenna communication devices 10 (fig. 1) and 10a (fig. 8). Therefore, the same reference numerals are given to the same components, and detailed description of the overlapping parts will be omitted. In the present embodiment, an example in which an adaptive array antenna is configured by using 4 antennas (unit antennas) 12 will be described.

The array antenna communication apparatus 10 according to the first and second embodiments described above is particularly effective when the delay time difference between the receiving unit (RX)32 and the transmitting/receiving unit (TRX)28 is smaller than the time interval of the sampling time, but the array antenna communication apparatus 10 according to the present embodiment can be applied even when the delay time difference is larger than the time interval of the sampling time.

As shown in fig. 7, the output signal of the second sampling processing section (a/D)101 is input to the correlation integrator 105 via a variable shift register 110 as delay time correction means. On the other hand, the output signal of the first sampling processing unit (a/D)102 is input to the correlation integrator 105 via the fixed shift register 111. Each correlation integrator 105 acquires a correlation integral value (correlation value) between the output signal of the variable shift register 110 and the output signal of the fixed shift register 111, and the determination circuit 106 controls the shift amount (delay amount) of the variable shift register 110 based on the correlation integral value. Specifically, when it is found that the output signal of the second sampling unit (a/D)101 is faster than the output signal of the first sampling unit (a/D)102 by 1 sampling interval or more, the determination circuit 106 increases the shift amount of the corresponding variable shift register 110 to increase the delay amount. On the other hand, when the output signal of the second sampling unit (a/D)101 is slower than the output signal of the first sampling unit (a/D)102 by 1 sampling interval or more, the decision circuit 106 decreases the shift amount of the corresponding variable shift register 110 to reduce the delay amount. With this configuration and control, the relative delay time corresponding to the signal passing through the fixed shift register 111 can be controlled in units of integer multiples of the sampling interval.

Further, the determination circuit 106 may correct the delay time within the sampling interval by adopting the configuration and method described in the first or second embodiment. The delay time correction using the variable shift register 110 and the delay time correction according to the first or second embodiment may be performed for both of them, or may be performed selectively according to the error of the delay time (that is, according to the determination result [ correlation integrated value ] in the determination circuit 106 in the above embodiment).

Effects of the invention

As described above, according to the present invention, even if there is a delay time difference between the receiving section (RX) provided in each unit antenna and the transmitting/receiving section (TRX) shared by a plurality of unit antennas, it is possible to correct it with high accuracy and quickly, and therefore, a significant effect is obtained that the control convergence characteristic using the adaptive processing section is improved.

Claims (4)

1. An array antenna communication apparatus using an adaptive array antenna including a plurality of unit antennas, characterized in that: is provided with

A plurality of RF transmission system circuits each including at least a transmission power amplifier, the RF transmission system circuits being provided for each of the unit antennas;

a plurality of RF receiving system circuits which are provided in parallel with the RF transmitting system circuit for each unit antenna and which include at least a low noise amplifier, wherein the difference between the amount of change in amplitude and the difference between the amount of phase rotation when a signal passes through the RF transmitting system circuit and the RF receiving system circuit for each unit antenna are set to be substantially equal between the unit antennas;

a plurality of bidirectional vector modulators respectively connected to the other ends of the RF transmitting circuit and the RF receiving circuit, which are connected in parallel, and which are opposite to the unit antenna connection end;

a distribution synthesis unit connected to the plurality of bidirectional vector modulators;

a transmission/reception unit (TRX) connected to the distribution/synthesis unit;

a first sampling processing unit for sampling the analog reception signal outputted from the transmission/reception unit;

a plurality of Receivers (RX) connected to the plurality of RF reception system circuits, respectively;

a plurality of second sampling units connected to the plurality of receiving units (RX), respectively, for sampling the analog reception signals outputted from the receiving units (RX);

a delay time correcting device for correcting a delay time of at least one of the output signal of the first sampling processing unit and the output signal of the second sampling processing unit;

and an adaptive processing unit for controlling the bidirectional vector modulator based on the output signal of the first sampling processing unit and the output signal of the second sampling processing unit corrected by the delay time correcting unit, so that the plurality of unit antennas function as adaptive array antennas, thereby reducing a symbol delay between the transmitting/receiving unit and the receiving unit.

2. The array antenna communication device according to claim 1, wherein:

the delay time correcting device includes a device for correcting a sampling timing of at least one of the first sampling processing unit and the second sampling processing unit.

3. The array antenna communication device according to claim 1 or 2, wherein:

the delay time correction device comprises a variable shift register.

4. The array antenna communication device according to claim 1, wherein:

the delay time correcting means corrects the delay time based on a correlation value between the output signal of the first sampling processing section and the output signal of the second sampling processing section corrected by the delay time correcting means.