JP2002190704A - Adaptive array antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adaptive array antenna system consisting of a limited number of components which can be applied to a multipathes environment. SOLUTION: The system is provided with a phase synthesis means for forming a beam by adjusting to the arriving directions of a received desired signal and a delay wave, a synthesis means for compensating phase delay of the output signals of the phase synthesis means, a demodulating means for demodulating the summed output of the synthesis part and obtaining a demodulation signal used for the calculation of the phase compensation quantity and the delay compensation quantity of the synthesis means, and a least square processing means for obtaining a weight value multiplied for forming the beam based on the delay compensation quantity of the synthesis means, the demodulation signal of the demodulating means and the reference signal of beam formation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adaptive array antenna apparatus which optimizes directivity according to a radio wave environment and suppresses an interference wave, and more particularly, forms a beam on a desired signal wave including a delay wave in a multipath environment. The present invention relates to an adaptive array antenna system.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing a configuration of a conventional adaptive array antenna device. In the figure, 1
, 1k denote the same type of antenna elements constituting the adaptive antenna, and 2a, 2b, ..., 2k perform analog-to-digital conversion of the signals received by the antenna elements 1a, 1b, ..., 1k, respectively. A / of the same kind
It is a D converter. .., 2k time-process the outputs of the A / D converters 2a, 2b,..., 2k in accordance with the delay time of the delayed wave.
y Line: TDL) circuit. TDL
In the configuration of the circuit 3a, 4a, 4b,..., 4n are delay elements of the same type, 5a, 5b,.
4b,..., 4n output weight values W11 and W11, respectively.
, W1n, and an adder 6 for synthesizing the multiplication results of the weighting units 5a, 5b,..., 5n. Reference numeral 7 denotes a synthesizing unit for adding the outputs of the TDL circuits 3a, 3b,.
Is a demodulation unit for demodulating the output of the synthesis unit 7. Numeral 9 is a reference signal used as a reference at the time of beam forming. Numeral 10 is a least square error method for obtaining weight values W11, W12,..., W1n of the TDL circuits 3a, 3b,. (MMSE: Minimum Means S
(Que Error) processing unit.

Next, the operation will be described. A signal wave including a delay wave in the desired signal is transmitted to each of the antenna elements 1a, 1b,.
1k, and A / D converters 2a, 2b,.
It is converted to a digital signal by k. The converted digital signals are weighted by the TDL circuits 3a, 3b,..., 3k with weight values W11, W12,. Each weight value is calculated by the least squares error processing unit 10
, 3k using the output of the synthesizing unit 7 and the reference signal 9 serving as a reference.
The calculation is performed so that the square error between the two is minimized. Accordingly, even if the arrival direction and delay time of the delayed wave change, the signal can be added to the desired signal in the same phase, so that the signal-to-noise ratio of the signal input to the demodulation unit 8 is improved.

Normally, weighting of a received signal is realized only by phase rotation by a complex multiplier, so that a delayed wave that is longer than the symbol timing of the received signal is canceled in the same manner as an interference wave. For this reason, the delay wave cannot be used for the demodulation processing, but the use of the TDL circuits 3a, 3b,..., 3k enables the delay wave to be used effectively.

[0005]

Since the conventional adaptive array antenna device is configured as described above,
Since the respective TDL circuits 3a, 3b,..., 3k are mounted corresponding to the number of the antenna elements 1a, 1b,..., 1k, a weight multiplication circuit having a scale proportional to the maximum delay time regardless of the number of delay waves. However, there were problems such as an increase in hardware scale.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to obtain an adaptive array antenna system which can be applied in a multipath environment with a small hardware scale.

[0007]

In the adaptive array antenna system according to the present invention, each received signal received by a plurality of antenna elements and converted from analog to digital is beam-formed in accordance with the arrival direction of a desired signal and a delayed wave. The number of phase synthesizing means corresponding to the number of delay waves to be added by rotating the phase as much as possible, and the phase and delay amount between each delay wave of the phase synthesizing means using the correction compensation amount and the delay compensation amount calculated based on the demodulated signal. Means for compensating for and adding the respective signals, a demodulating means for demodulating the added output of the combining unit and supplying it to the combining means as a demodulated signal used for calculating the phase compensation amount and the delay compensation amount of the combining means, and a delay of the combining means. From the compensation amount, the demodulated signal of the demodulation means and the reference signal used as a reference for beam forming, each weight value to be multiplied by each phase synthesis means for phase rotation is determined. It is obtained by a least square error method processing unit.

In the adaptive array antenna system according to the present invention, each phase synthesizing means multiplies each analog-to-digital converted received signal by a respective weight value, and calculates each multiplication result of the weighting section. And an adder for combining.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration of an adaptive array antenna system according to Embodiment 1 of the present invention. Corresponding parts in FIG. 2 are denoted by the same reference numerals. In the figure, 1a, 1b, ..., 1k are antenna elements constituting an adaptive antenna, and 2a, 2b, ...,
Reference numeral 2k denotes an A / D converter of the same type for performing analog-to-digital conversion of the received signals received by the antenna elements 1a, 1b,..., 1k. 11a, 11b, ..., 11
n is a phase synthesizing unit (phase synthesizing means) of the same type which rotates the digital outputs of the A / D converters 2a, 2b,..., 2k in accordance with the arrival directions of the desired signal and the delayed signal, and adds them. is there. In the phase synthesis unit 11a, 5
, 5k are A / D converters 2a, 2b,.
The weight values W11, W12,...
A weighting unit of the same type for multiplying W1k, and 6 is an adder for combining the multiplication results of the weighting units 5a, 5b,..., 5k. Numeral 7 denotes a synthesizing unit (synthesizing means) for compensating for the delay amount of each delay wave output from the phase synthesizing units 11a, 11b,... Reference numeral 8 denotes a demodulation unit (demodulation means) for demodulating the output of the synthesis unit 7. Reference numeral 9 denotes a reference signal used as a reference at the time of beam combining. Reference numeral 10 denotes a weighting unit 5a, 5b,...
.., W1k for determining the respective weight values W11, W12,..., W1k.

Next, the operation will be described. The signal wave including the delay wave in the desired signal is transmitted to each of the antenna elements 1a, 1b,.
k and received by the A / D converters 2a, 2b,.
Is converted into a digital signal. These digital signals are phase-combined by 11a,
11b, a beam is formed in the arrival direction of each delayed wave. The weighting weight values W11, W12,..., W1k for beamforming are the demodulated signal of
It is calculated and determined by the least squares error processing unit 10 based on the delay compensation amount of the combining unit 7 and the reference signal 9 serving as a reference for beam forming. Each of the phase synthesis units 11a, 11b,.
The outputs of 1n are combined after the combining unit 7 compensates for the phase and the amount of delay between the delayed waves. The compensation of the phase and the delay amount is performed using the phase compensation amount and the delay compensation amount calculated based on the demodulated signal provided from the demodulation unit 8. The synthesized signal is demodulated by the demodulation unit 8 and then output as demodulated data.

As described above, according to the first embodiment, even when the amount of delay between delayed waves is large, antenna element 1
a, 1b,..., 1k, but not for each output.
Since the outputs of a, 11b,..., 11n are compensated for in the synthesizer 7, the multiplier for weighting conventionally used can be reduced, and the effect of reducing the hardware scale as compared with the TDL circuit can be obtained.

[0012]

As described above, according to the present invention, a phase rotation is performed so that each received signal received by a plurality of antenna elements and converted from analog to digital is beam-formed in accordance with the arrival direction of a desired signal and a delayed wave. And compensating the phase and the delay amount between the delay waves of the phase combining means using the number of phase combining means corresponding to the number of delayed waves to be added and the amount of phase compensation calculated based on the demodulated signal and the amount of delay compensation. Synthesizing means for demodulating the added output of the synthesizing section and supplying the demodulated signal to the synthesizing means as a demodulated signal used for calculating the phase compensation amount and the delay compensation amount of the synthesizing means; A least squares error processing means for determining each weight value to be multiplied by each phase synthesizing means for phase rotation from the demodulated signal of the demodulating means and a reference signal serving as a reference for beam forming. With such a configuration, the delay wave can be weighted and synthesized by the phase synthesizer corresponding to the number of delay waves, and the delay wave can be synthesized with the output by the delay circuit (synthesis unit) into a desired signal. Conventional T
There is an effect that the hardware scale is reduced as compared with the method using the DL circuit, and the apparatus can be configured inexpensively.

According to the present invention, each phase synthesizing means includes a weighting section for multiplying each of the analog-to-digital converted received signals by a respective weight value, and an adder for synthesizing each multiplication result of the weighting section. Therefore, there is an effect that the circuit configuration can be simplified because only the delayed wave beam formation is mainly performed and no delay circuit is provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an adaptive array antenna device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional adaptive array antenna device.

[Explanation of symbols]

, 1k antenna elements, 2a, 2b,
..., 2k A / D converters, 3a, 3b, ..., 3k TD
L circuit, 4a, 4b,..., 4n delay element, 5a, 5
b,..., 5k weighting unit, 6 adder, 7 combining unit (synthesizing unit), 8 demodulating unit (demodulating unit), 9 reference signal, 10 least square error method processing unit (least square error method processing unit), 11a, 11b,..., 11n Phase synthesis unit (phase synthesis means), W11, W12,.

Claims (2)

[Claims] 1. A method according to the number of the delayed waves to be received, which are received by a plurality of antenna elements and converted from analog to digital, are phase-rotated and beam-formed to form a beam in accordance with the arrival direction of a desired signal and a delayed wave. Combining means for compensating and adding the phases and delay amounts between the respective delayed waves of the phase combining means using the phase compensation amounts and the delay compensation amounts calculated based on the demodulated signals. Demodulating means for demodulating the added output of the combining unit and supplying the demodulated signal to the combining means as the demodulated signal for use in calculating the phase compensation amount and the delay compensation amount of the combining means; and From the demodulated signal of the demodulation means and a reference signal serving as a reference for beamforming, each phase synthesizing means determines a respective weight value to be multiplied for the phase rotation. An adaptive array antenna system comprising a small square error method processing means. 2. Each phase synthesizing means includes a weighting unit for multiplying each of the analog-to-digital converted received signals by a respective weight value, and an adder for synthesizing each multiplication result of the weighting unit. 2. The adaptive array antenna system according to claim 1, wherein: