JP2001044903A - Adaptive antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a hardware scale and also to stably perform operation even in an environment in which transmission quality is deteriorated remarkably. SOLUTION: This device is provided with a 1st A/D converter 105 converting an output of an analog beam forming circuit 102 weighting and synthesizing an input signal from each antenna element into a digital signal, a 1st clock generator 115 generating a sampling clock used for conversion here, 2nd converters performing the A/D conversion of the input signal from each antenna element and a 2nd clock generator generating the sampling clock used for the conversion here. Here, the generator 115 does not synchronize with >=2 times frequency of a transmission rate but performs oscillation so as to sample in an interval being almost the same as that of delay time of each delay element of a traversal filter, and the 2nd sampling clock is prevented from being synthesized with the 1st sampling clock.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an adaptive antenna device, and more particularly, to directivity control and waveform equalization of an antenna for a wireless communication system.

[0002]

2. Description of the Related Art An adaptive antenna apparatus is an antenna apparatus that synthesizes an incoming wave having a high correlation with a desired signal and controls directivity so as to suppress an incoming wave having a low correlation.

FIG. 25 shows a conventional adaptive antenna device (for example, RAMonzingo and TWMiller, Introductio).
n to Adaptive Arrays, John Wiley & Sons, Inc. 198
0).

This adaptive antenna apparatus includes a plurality of N antenna elements 13011 to 1301N and
Weighting means 13021 to 1302N for assigning complex weights to outputs of 011 to 1301N;
Weight controller 130 for controlling weights of 21 to 1302N
3, a reference signal generator 1304, and a combiner 1305 provided at the output of each of the plurality of antenna elements 13011 to 1301N, for combining complex-weighted signals.
Consists of

A plurality of antenna elements 1 of the adaptive antenna device
Let x1 to xN be the signals received by 3011 to 1301N, w1 to wN be the weight values set in the weighting means 13021 to 1302N, and let d be the desired signal component, then the square of the error from the desired signal The weight value that forms the directivity so that

[0006]

(Equation 3)

[0007]

In the adaptive antenna device, the directivity is changed so that an error between an output signal and a desired signal is minimized. Therefore, when the synchronization characteristics are not stable,
A large error occurs in r _xd , and the adaptive antenna device does not operate normally.

FIG. 26 shows a conventional adaptive antenna apparatus using a transversal filter (Philip Balaban, an
d Jack Salz, “Dual Diversity and Equalization in
Digital Cellular Mobile Radio ”, Transaction on V
EHICULAR TECHNOLOGY, VOL.40, NO.2, MAY 1991.). In this figure, reference numerals 14011 to 1401N denote antenna elements, 1402 denotes a beam forming circuit, 14031 to 1
403N is a first weighting means, 1404 is a first combiner, 1405 is a transversal filter, 14061
1406M are delay elements, 14070 to 1407M are second weighting means, 1408 is a second combiner, 1412
Denotes an automatic frequency converter control device, 1413 denotes a timing reproduction circuit, and 14141 to 1414N denote A / D converters.

FIG. 27 shows the first weighting means 140
31 to 1403N and second weighting means 14070-
FIG. 2 is a diagram illustrating a configuration of 1407M,
94 is a real number multiplier, 1410 is a real number subtractor, and 1411 is a real number adder.

The signal received by each antenna element has the same clock as the clock of the signal being received by the timing recovery circuit 1413, and the A / D converters 14141 to 1414N use the recovered clock to perform A / D conversion.
/ D conversion and input to the beam forming circuit 1402.

The output signal of beam forming circuit 1402 is represented by y _b
(t), the second weighting means 10470 to 104
The 7M weight values c0 to cM are

[0013]

(Equation 4)

## EQU1 ##

[0015]

In the above-mentioned adaptive antenna apparatus, since signal information at each antenna is actually required, it is necessary to convert a received signal at each antenna into a digital signal by an A / D converter. is there. If the sampling rate is different from the signal rate at that time, the beam forming circuit will be controlled with the data whose timing has not been compensated, so that the algorithm with the minimum square error cannot be applied.

Further, since the waveform equalization is performed by both the transversal filter unit and the beam forming circuit, the operation is not stable. Further, since the second weighting means is a complex number, the hardware scale increases.

That is, in digital radio transmission, transmission quality is degraded by a delay wave exceeding one symbol length, and transmission quality is significantly degraded by an interference wave, and timing synchronization characteristics are degraded. In the conventional adaptive antenna device, if the timing synchronization characteristic is deteriorated, the algorithm for minimizing the square error cannot be applied, and the adaptive antenna device does not operate.

The present invention has been made in view of such problems, and its object is to reduce the hardware scale, eliminate feedback to the sampling clock, and significantly degrade the transmission quality. An object of the present invention is to provide an adaptive antenna device that can operate stably even in an environment.

[0019]

In order to achieve the above object, an adaptive antenna apparatus according to a first aspect of the present invention includes a plurality of antenna elements, each of which is connected to each of the plurality of antenna elements. An analog beam forming circuit that weights and combines the input signals from the first and second weighting means, and a first A / D that converts an output signal of the analog beam forming circuit into an input signal, converts the signal into a digital signal, and outputs the digital signal
A converter, a first frequency converter for converting the input signal converted into a digital signal by the first A / D converter into a baseband signal, and a fractional symbol length in an output of the first frequency converter. A plurality of delay elements having a delay time of are connected in series, the output of each delay element is weighted by a second weighting means, and a first transversal filter with a fractional symbol length interval to be synthesized is combined with each of the antenna elements. , Or both the received signal at each of the antenna elements and the output signal of the first transversal filter are input signals, and the input signals from each of the antenna elements are converted by the second A / D converter. After the A / D conversion, the first digital signal processing device calculates a weight value used by the first weighting means, a first weight control circuit, and a first frequency control circuit. An output signal of the converter as an input signal, a second weight control circuit for calculating a value of weight used in the second weighting means, and an output signal of the first transversal filter as an input signal; A frequency converter automatic control device for controlling the first frequency converter so as to reduce a frequency conversion error in the frequency converter of the first embodiment, and a first sampling clock for the first A / D converter. A first sampling clock generator for generating a second sampling clock in the second A / D converter; and a first sampling clock generator for generating a second sampling clock in the second A / D converter. At a frequency that is at least twice the transmission rate, is not synchronized with the transmission rate, and is supported at substantially the same interval as the delay time of the delay element of the first transversal filter. Oscillates to pulling, the second sampling clock is a said first sampling clock so as not to synchronize.

The adaptive antenna apparatus according to a second invention is the adaptive antenna apparatus according to the first invention, wherein a second frequency converter is provided inside the first weight control device, and the second frequency converter is provided. Thus, the input signal from each antenna element is converted into an intermediate frequency signal.

The adaptive antenna device according to a third invention is the adaptive antenna device according to the first invention, wherein the second frequency is connected to each of the antenna elements and converts an input signal from each of the antenna elements into an intermediate frequency signal. A converter is provided, and the intermediate frequency signal converted by the second frequency converter is input to the first weight control device.

The adaptive antenna apparatus according to the fourth invention is connected to a plurality of antenna elements and each of the plurality of antenna elements, and weights an input signal from each of the antenna elements by first weighting means. An analog beam forming circuit for synthesizing the signal, a first frequency converter for frequency-converting an output signal of the analog beam forming circuit as an input signal to a baseband signal, and digitally converting the baseband signal from the first frequency converter. A first A / D converter for converting the signal into a signal, and a plurality of delay elements having a fractional symbol length delay time connected in series to the output of the first A / D converter; Are weighted by the second weighting means, and only the first transversal filter with a fractional symbol length interval to be combined and the received signal at each of the antenna elements are used. After both the received signal at each of the antenna elements and the output signal of the first transversal filter are input signals, and the input signals from each of the antenna elements are A / D converted by a second A / D converter. A first digital signal processing device, a first weight control circuit for calculating a value of weight used in the first weighting means, an output signal of the first frequency converter as an input signal, A second weight control circuit for calculating the value of the weight used in the weighting means, and an output signal of the first transversal filter as an input signal, so as to reduce a frequency conversion error in the first frequency converter. A frequency converter automatic controller for controlling the first frequency converter,
A first sampling clock generator for generating a first sampling clock in the first A / D converter;
A second sampling clock generator for generating a second sampling clock in the second A / D converter, wherein the first sampling clock generator has a frequency of twice or more the transmission rate. Oscillates so as not to synchronize with the transmission rate, but to sample at substantially the same interval as the delay time of the delay element of the first transversal filter, and the second sampling clock is different from the first sampling clock. Avoid synchronization.

The adaptive antenna apparatus according to a fifth aspect of the present invention includes a plurality of antenna elements and a first antenna connected to each of the plurality of antenna elements for converting an input signal from each of the antenna elements into a digital signal. An A / D converter, a digital beam forming circuit for weighting and combining a signal converted to a digital signal by the first A / D converter by first weighting means, and an output signal of the digital beam forming circuit A first frequency converter for converting the input signal into a baseband signal, and a plurality of delay elements having a fractional symbol length delay time at the output of the first frequency converter are connected in series. A first transversal filter having a fractional symbol length interval for weighting and combining outputs of the delay elements by second weighting means, and the first A / D converters Using only the A / D-converted digital signal or both the digital signal A / D-converted by each of the first A / D converters and the output signal of the first transversal filter as an input signal, A first weight control circuit for calculating a weight value used in the first weighting means, an output signal of the first frequency converter as an input signal, and a first digital signal A second weight control circuit that calculates a value of the weight used by the second weighting means,
A frequency converter automatic control device for controlling an output signal of the first transversal filter as an input signal to reduce a frequency conversion error in the first frequency converter, and the first A / D converter And a first sampling clock generator for generating a first sampling clock in the first sampling clock, wherein the first sampling clock is:
Oscillation is performed at a frequency of twice or more the transmission rate, not in synchronization with the transmission rate, and sampling at substantially the same interval as the delay time of the delay element of the first transversal filter.

The adaptive antenna apparatus according to a sixth aspect of the present invention is the adaptive antenna apparatus according to the fifth aspect, further comprising a second frequency converter connected to each of the antenna elements and converting an input signal into an intermediate frequency signal. The intermediate frequency signal converted by the second frequency converter is input to the first A / D converter.

An adaptive antenna device according to a seventh aspect of the present invention includes a plurality of antenna elements and a first antenna connected to each of the plurality of antenna elements for frequency-converting an input signal from the antenna element into a baseband signal. , A first A / D converter for converting a baseband signal from the first frequency converter into a digital signal, and a first A / D converter
A digital beam forming circuit for weighting and synthesizing a signal converted into a digital signal by the D converter by a first weighting means, and a plurality of delay elements having a fraction symbol length delay time at the output of the digital beam forming circuit. A first transversal filter having a fractional symbol length interval, which is connected in series, and which weights the output of each delay element by a second weighting means and combines the first and second A / Ds;
An input signal of only the digital signal A / D-converted by the converter, or both the digital signal A / D-converted by each of the first A / D converters and the output signal of the first transversal filter A first digital signal processing device, a first weight control circuit for calculating the value of the weight used in the first weighting means, an output signal of the digital beam forming circuit as an input signal, the first digital The signal processing device, a second weight control circuit that calculates the value of the weight used in the second weighting means, the output signal of the first transversal filter as an input signal, in the first frequency converter A frequency converter automatic controller for controlling so as to reduce a frequency conversion error, and a first sampling clock generated by the first A / D converter. A first sampling clock generator, wherein the first sampling clock has a frequency of twice or more the transmission rate, is not synchronized with the transmission rate, and has a delay of the delay element of the first transversal filter. It oscillates so as to sample at substantially the same interval as time.

An adaptive antenna apparatus according to an eighth aspect of the present invention is the adaptive antenna apparatus according to any one of the first to seventh aspects, wherein it is determined whether or not the second weight control circuit has a frequency-selective fading environment. A propagation environment diagnostic device, the weighting of the second weighting means in the first transversal filter unit is frequency-selective fading when the weight of the second weighting means is a real number, and the frequency selection fading If not, the weight of the second weighting means is switched to a complex number.

According to a ninth aspect of the present invention, in the adaptive antenna device according to any one of the first to eighth aspects,
The second weight control device uses a modulation method in which the amplitude at the identification timing for performing the code determination is a discrete value, and performs the decoding and the timing at which the input signal is sampled by the first A / D converter. The storage device storing the optimal set of weights of the second weighting means corresponding to the deviation from the optimal timing of the storage device, and the weight of each second weighting device stored in the storage device, A transmission quality estimating device for estimating a deviation of the amplitude at the output of the transversal filter from the discrete value, wherein the transmission quality of the set of weights of the second weighting means stored in the storage device is The set in which the deviation of the amplitude of the output signal estimated by the estimating device from the discrete value is minimized is set as the weight value of the second weighting means.

The tenth invention is directed to the first, second, fifth,
In any one of the inventions described in 6, 8, and 9, the first digital signal processing device includes a reference signal generation unit that generates a reference signal d; A fourth frequency converter for converting the frequency with the same characteristics as the device, and a second transversal filter for converting the output signal of the fourth frequency converter with the same characteristics as the first transversal filter And the signal x′i (i = i = i) converted by the fourth frequency converter and the second transversal filter.
, NN: number of elements), the weight value w _opt i (i = 1,..., N) of the first weighting means is determined by the following equation.

[0029]

(Equation 5)

The eleventh invention is the third, fourth, seventh and ninth aspects.
In any one of the inventions, the first digital signal processing device includes a reference signal generation unit that generates a reference signal d, and an input signal from each of the antenna elements having the same characteristics as the third frequency converter. A fourth frequency converter for frequency conversion, and a second transversal filter for converting the output signal of the fourth frequency converter with the same characteristics as the first transversal filter, The signal x′i (i = 1,..., N) converted by the fourth frequency conversion unit and the second transversal filter.
N: the number of elements), the weight value w of the first weighting means
_opt i (i = 1,..., N) is determined by the following equation.

[0031]

(Equation 6)

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

First, a first embodiment will be described.
In the first embodiment, an N-element array antenna is used, sampling is performed at an arbitrary timing by the first A / D converter and the second A / D converter, and the second transversal filter of the first transversal filter is used. In which the weight of the weighting means is a real number.

FIG. 1 is a diagram showing the configuration of the first embodiment of the present invention. In FIG. 1, reference numerals 1011 to 101
N is an antenna element, 102 is an analog beam forming circuit,
1031 to 103N are first weighting means, 104 is a first synthesizer, 105 is a first A / D converter, 106 is a first frequency converter, 107 is a first transversal filter, 1081 to 108M Is a delay element;
09M is a second weighting means, 110 is a second combiner,
111 is a first weight control circuit, 114 is a second weight control circuit, 115 is a first sampling clock generator, 1
Reference numeral 17 denotes a frequency converter automatic control device.

FIG. 2 is a diagram showing the configuration of the above-mentioned first weighting means 1031 to 103N, where 119 is a variable amplifier, and 120 is a variable phase shifter.

FIG. 3 is a diagram showing a configuration of the above-mentioned first weight control circuit 111, wherein 1121 to 112N are second A / D converters, 113 is a first digital signal processor, 116 Is a second sampling clock generator.

FIG. 4 shows the second weighting means 109.
FIG. 3 is a diagram showing a configuration of 0 to 109M,
2 is a real number multiplier. In the above configuration, signals x1 to xN received by the antenna elements 1011 to 101N are used.
Is input to the analog beam forming circuit 102 and the first weight control circuit 111. However, when the reception level is low, the signal received by each antenna is amplified by a low noise amplifier and then input to the analog beam forming circuit 102 and the first weight control circuit 111. In the analog beam forming circuit 102, the first weighting means 1031 to 1 for changing the amplitude and phase of the input signal from each antenna.
03N, weighting is applied to w1 to wN to obtain weighted signals w1x1, w2x2,..., WNxN.
The change of the amplitude and the phase is realized by, for example, connecting the variable amplifier 119 and the variable phase shifter 120 in cascade and controlling each of them. Each weighted signal is converted to a first combiner 104
And an output signal y is obtained. Here, y is expressed as y = w1x1 + w2x2 +... + WNxN.

The synthesized signal y is supplied to the first A / D converter 1
05 and converted into a digital signal. The signal y converted into a digital signal is supplied to the first frequency converter 1
06, the real part and the imaginary part of the baseband signal are separated (for example, Shinonaga et al., “Digital I / Q detection technology”, Technical Report of IEICE SANE94-59
(1994-11) pp. 9-15).

The output of the first frequency converter 106 is input to the first transversal filter 107 and the second weight control circuit 114, and the delay time T _s / a (T _s is the symbol length of the digital signal, a is (Real number of 2 or more) delay element 1
081 to 108M are input to the M delay units connected in series, and m × T _s / a (m = 0,..., M) for the input signal
Generate M + 1 delayed signals that are delayed.

Each delayed signal is supplied to the second weighting means 1090.
Are multiplied by real weights C0 to CM, respectively.
Each multiplication result is fully added by the second combiner 110 and output from the first transversal filter 107.
Multiplication with real weights is performed by real multipliers 1181 and 1182.
Reproduced by The complex weighting circuit performs the following calculation using the real number multipliers 1181 and 1182.

(Real part of output after real number weighting) = (weight) * (real part of signal to be weighted) (imaginary part of output after real number weighting) = (weight) * (imaginary part of signal to be weighted) The output signal (both real and imaginary parts) of the first transversal filter 107 is the output of the adaptive antenna device of the present invention.

First weighting means 1031 for determining the directivity pattern formed by analog beam forming circuit 102
In the first weight control circuit 111, the weight value of each of the antenna elements 1011 to 101N is determined based on only the reception signals x1 to xN of the antenna elements 1011 to 101N, or
It is determined by using the received signals x1 to xN at 011 to 101N and the output signal of the first transversal filter 107.

In the first weight control circuit 111, the signals received by the antenna elements 1011 to 101N are converted into digital signals by the second A / D converters 1121 to 112N using the clock of the second sampling clock generator 116. Converted to a signal. At this time, the second sampling clock of the second sampling clock generator 116 may or may not be the same as the first sampling clock.

For example, as a method using only x1 to xN, y '= w1x1 + w2x2 +... + WNxN is obtained as wn = exp (jnθ), and wn at which y' is maximized is determined.

In addition, for example, CMA algorithm, MMSE algorithm, DC
The value of the weight of the first weighting means is determined using an algorithm such as an MP algorithm or a power inversion algorithm.

(1) Kikuma, "Adaptive Signal Processing by Array Antenna," Science and Technology Publishing, September 20, 1998 (2) RAMonzingo and TWMiller, 'Introduction
to Adaptive Arrays, 'John Wiley & Sons, Inc. 1980 However, when using an algorithm that needs to convert the received signals x1 to xN at each antenna into baseband signals, the first digital signal processing device 113 Perform the same frequency conversion as that of the first frequency converter 106, determine the real part and the imaginary part of the baseband signal, and operate the algorithm on the values.

The first transversal filter 1
The value of the weight of the second weighting means 1090 to 109M at 07 can be determined, for example, by applying an algorithm described in the following document.

(1) RWLuck, “Automatic equalizati
on for digital communication ”, Bell Syst. Tech.
J., 44, 4, p.547 (1965). (2) RWLuck and HRRudin, “An automatic equal
izer for general-purpose communication channels ”,
Bell Syst. Tech. J., 46, 9, p. 2179 (1967). In a conventional adaptive antenna apparatus using a transversal filter, the second weights C0 to CM are set to complex numbers, and are used for waveform equalization. . However, in order to operate the adaptive antenna apparatus in an environment where the timing cannot be synchronized, the operation is not stable with the conventional configuration. Therefore, in the present invention, the first transversal filter 107 uses the second weights C0 to CM as real numbers and performs timing synchronization compensation. In the following, the principle of timing synchronization compensation when the second weights C0 to CM of the first transversal filter 107 are real numbers will be described.

In the case where the QAM modulation method is used, if the in-phase component signal of the k-th signal is represented by I _k and the quadrature component signal is represented by Q _k , the carrier frequency is f and the impulse response of the band limiting filter is h ( t), the baseband signal s
(t) is

[0050]

(Equation 7)

Is represented by Generally, in digital communication,
In order to prevent intersymbol interference from occurring, the band-limiting filter sets the Nyquist condition h (kT _s ) = 0 (k =. , 2 ,.
・ ・) (Here, h (0) ≠ 0) is designed. Here, t = kT _s is referred to as identification timing. If sampling is performed at a timing shifted by Δτ from the identification timing, since h (kT _s + Δτ) ≠ 0, intersymbol interference occurs and transmission characteristics deteriorate.

[0052] For example, when _{t = 3T s, s (t} ) is out of the series sum of (Equation 11), I3 + JQ3 And t = 3
The signal of T _s can be extracted. However, t = 3T
_{At s} + Δτ, the series sum cannot be removed, so I2
+ JQ2 And I4 + JQ4 For example, signals at other times interfere with each other, resulting in intersymbol interference.

The number of delay elements at the output of the beam forming circuit is M, and the weight values of the second weighting means are c0 to c.
If M, the output signal y (t) of the first transversal filter is

[0054]

(Equation 8)

Is as follows. In order to restore the baseband signal with the output of the first transversal filter 107, the following equation may be obtained from (Equation 11) and (Equation 12).

[0056]

(Equation 9)

Since the frequency converter automatic controller 117 controls the frequency conversion error in the first frequency converter 106 to be small, Δf = 0 in the convergence state, and (Equation 13) becomes

[0058]

(Equation 10)

Is as follows. From equation (14), if the impulse response of the band-limiting filter is a real number, c0 to cm
Is a real number.

FIG. 24 shows a case where the adaptive antenna apparatus is used and the weight of the second weighting means of the first transversal filter is a complex number, and the coefficients are controlled so that the square error with respect to the received signal is minimized. Transmission speed and output SI
The result of having compared the characteristic of NR is shown.

The environment was an indoor propagation environment of 20 m × 20 m. The output SINR was an average value of 10,000 symbols transmitted. In the simulation, the delay time of the delay element of the first transversal filter 107 in this configuration was 0.5, and the number of delay elements was three. The sampling frequency in the first A / D converter 105 is a frequency shifted from twice the baud rate to 1000 ppm.

When comparing the case where the number of elements is set to four, as can be seen from the figure, in this adaptive antenna apparatus, the weight of the second weighting means of the first transversal filter 107 is constituted by a real number. However, the output SINR characteristics with respect to the transmission speed almost coincide with the case of using a complex number.

By using this configuration, the first transversal filter 107 can perform only timing compensation. Therefore, the analog beam forming circuit 1
02, only the transmission quality is improved, and the first transversal filter 107 performs only the timing compensation. Even in an environment where the transmission quality is significantly deteriorated,
Stable operation is realized.

Since the second weighting means is a real number, the hardware configuration of the first transversal filter 107 is reduced to about half.

Next, a second embodiment of the present invention will be described. In the second embodiment, an N-element array antenna is used, sampling at the first A / D converter and the second A / D converter is performed at an arbitrary timing, and the second transversal filter of the first transversal filter is used. In the adaptive antenna device with the weight of the weighting means of the real number, in the first weight control device,
A form in which a signal received by each antenna is frequency-converted into an IF (intermediate frequency) signal by a second frequency converter and then A / D converted is adopted.

Next, a second embodiment of the present invention will be described. FIG. 5 is a diagram showing a configuration of the second exemplary embodiment of the present invention. Here, the same components as those described with reference to FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. In FIG. 5, reference numerals 2011 to 201N
Is a second frequency converter, and 202 is an oscillator. Also,
FIG. 6 is a diagram showing a configuration of the second frequency converters 2011 to 201N. Reference numeral 203 denotes a mixer,
Is a low-pass filter.

In this configuration, each of the antennas 1011 to 1011
The signal received by the first weight control circuit 111N
, And after being frequency-converted into an IF signal by the second frequency converters 2011 to 201N, the second A / D
A / D conversion is performed by converters 1121 to 112N. In each of the second frequency converters 2011 to 201N, the input signals from the antenna elements 1011 to 101N and the signal from the oscillator 202 are input to the mixer 203, and the output of the mixer is input to the low-pass filter 204, It is output after the components are suppressed.

By using this configuration, it is possible to convert a signal received by each antenna element into an IF signal having completely the same center frequency, and to reduce the input frequency to the A / D converter. It is possible to increase the frequency band of the RF frequency in the section and reduce the power consumption of the A / D converter.

Next, a third embodiment of the present invention will be described. In the third embodiment, the signal received by each antenna element is converted into an IF signal by the second frequency converter, and the converted IF signal is input to the analog beam forming circuit and the first weight control device. I do.

FIG. 7 is a diagram showing the configuration of the third embodiment of the present invention. Here, the same components as those described in FIGS. 1 to 6 are denoted by the same reference numerals, and description thereof will be omitted.

In this configuration, each antenna element 101
The signals received at 1 to 101N are transmitted to the second frequency converter 2
After being frequency-converted into IF signals by 011 to 201N, they are input to the analog beam forming circuit 102 and the first weight control circuit 111.

By using this configuration, each antenna element 1
Since the signals received at 011 to 101N can be converted into IF signals having completely equal center frequencies, the analog beam forming circuit 102 can be configured in the IF band. Therefore, it is possible to increase the frequency band of the RF frequency in the wireless section, reduce the power consumption of the A / D converter, and reduce the frequency of the analog beam forming circuit 102.

Next, a fourth embodiment of the present invention will be described. The fourth embodiment adopts a mode in which after analog beam forming, a received signal is frequency-converted by an analog frequency converter, and then A / D conversion is performed.

FIG. 8 is a diagram showing the configuration of the fourth embodiment of the present invention. Here, the same components as those described in FIGS. 1 to 6 are denoted by the same reference numerals, and description thereof will be omitted. 8, reference numeral 401 denotes a third frequency converter having a configuration as shown in FIG. 9, reference numerals 4021 and 4022 denote mixers, 403 denotes a π / 2 phase shifter, 4041 and 4042 denote low-pass filters, and 405 denotes an oscillator.

The output of the analog beam forming circuit 102 is
The signal is input to the third frequency converter 401. In the third frequency converter 401, the output of the analog beam forming circuit 102 is branched into two and input to other mixers 4021 and 4022. That is, the output signal of the analog beam forming circuit 102 and the sine wave from the oscillator 405 are input to the mixer 4021, and the output of the mixer 4021 is input to the low-pass filter 4041, and the harmonics are suppressed.

On the other hand, an output signal of the analog beam forming circuit 102 and a signal obtained by passing a sine wave from the oscillator 405 through a π / 2 phase shifter 403 are input to the mixer 4022. That is, as the sine wave from the oscillator 405, a sine wave whose π / 2 phase is delayed by the π / 2 phase shifter 403 with respect to the sine wave input to the mixer 4021 is input. Therefore,
The low-pass filters 4041 and 4042 output the in-phase component (real part) and the quadrature component (imaginary part) of the baseband signal (for example, Saito, "Modulation and Demodulation of Digital Wireless Communication").
(Edited by the Institute of Electronics, Information and Communication Engineers, issued on August 20, 1996).

The outputs of the real part and the imaginary part of the third frequency converter 401 are A / D converted by the first A / D converter 105, respectively. The oscillation frequency of the oscillator 405 is controlled by the automatic frequency converter controller 117 so that the center frequency at the output of the first transversal filter 107 becomes zero.

When this configuration is used, A / D conversion using a baseband signal may be performed, so that the power consumption of the A / D converter can be reduced.

Next, a fifth embodiment of the present invention will be described. FIG. 11 is a diagram showing the configuration of the fifth embodiment, and shows a form in which the beam forming circuit is digitally configured. Here, the same components as those described in FIGS. 1 to 10 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 11, reference numerals 5011 to 5011
1N is a first A / D converter, 502 is a sampling clock generator for providing sampling timing used in the first A / D converters 5011 to 501N, and 503 is a digital beam forming circuit. FIG. 10 shows a configuration of the first weighting means 1031 to 103N. Reference numerals 5041 to 5044 denote multipliers, 505 denotes a real number subtractor, and 506 denotes a real number adder.

The signals received by the antenna elements 1011 to 101N are converted into digital signals by the first A / D converters 5011 to 501N, and the received signals are separated into real and imaginary parts. An example of a method of separating a real part and an imaginary part is described below.

(1) Each antenna element 1011 to 101N
A / D conversion is performed on the received signal at the sampling frequency of twice or more the center frequency and Hilbert transform is performed. (For example, Oppenheim and Shafer, “Digital Signal Processing”, Corona, vol. 2, pp. 26-
(2) The received signals from the antenna elements 1011 to 101N are sampled at four times the center frequency, the even-numbered sampled signal is taken as the real part, and the odd-numbered signal is taken as the imaginary part. Then, the real part and the imaginary part are separated.

(3) The received signal is separated into two signals, and one of the signals is caused to have a phase delay of π / 2 at the center frequency with respect to the other signal.
01N. A / D converters 5011 to 501N
Then, sampling is performed at twice or more the center frequency to obtain an output. Each output is a real part and an imaginary part, respectively.

The A / D-converted signal is input to the digital beam forming circuit 503 and the first weighting means 103
After weighting the complex numbers by 1 to 103N, they are combined by the first combiner 104 and output. Here, the complex number weighting by the first weighting means 1031 to 103N is realized as follows.

As described above, each first A / D converter 5
In the outputs at 011 to 501N, the real part and the imaginary part are output separately. Further, since the weight value for performing weighting is also a complex number, it can be separated into a real part and an imaginary part. In the weighting means, (real part of output after complex number weighting) = (real part of complex weight) * (real part of weighted signal) − (imaginary part of complex weight) * (imaginary part of weighted signal) The operation of (imaginary part of complex weighted output) = (real part of complex weight) * (imaginary part of weighted signal) + (imaginary part of complex weight) * (real part of weighted signal) is performed. Thus, complex weighting is realized.

By using this configuration, beam forming by digital signal processing can be realized, and stable beam forming can be realized without depending on temperature, so that highly accurate beam control becomes possible.

Next, a sixth embodiment of the present invention will be described. The sixth embodiment adopts a mode in which a signal received by each antenna element is converted into an IF signal, and the converted IF signal is input to a digital beam forming circuit and a first weight control device.

FIG. 12 is a diagram showing the configuration of the sixth embodiment of the present invention. Here, the same components as those described in FIGS. 1 to 11 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 12, in this configuration,
The signals received by the antennas 1011 to 101N are frequency-converted into IF signals by the second frequency converters 2011 to 201N, A / D converted, and input to the digital beam forming circuit 503.

By using this configuration, it is possible to convert a signal received by each antenna element into an IF signal having completely the same center frequency. Therefore, it is necessary to increase the frequency band of the RF frequency in the radio section. The power consumption of the D converter can be reduced.

Next, a seventh embodiment of the present invention will be described. In the seventh embodiment, a signal received by each antenna element is detected and frequency-converted into a baseband signal.
A form in which D conversion is performed and input to a digital beam forming circuit is employed.

FIG. 13 is a diagram showing the configuration of the seventh embodiment of the present invention. Here, the same components as those described in FIGS. 1 to 12 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 13, reference numerals 7011 to 7011
1N is a third frequency converter, the configuration of which is as described in FIG. Reference numeral 702 is an oscillator.

The received signals received by each of the antenna elements 1011 to 101N are converted into second frequency converters 2011 to 201N.
After being converted into an IF signal by the third frequency converter 7011 to 701N. Here, the input signals of the third frequency converters 7011 to 701N are signals in the IF band, but the second frequency converters may be omitted and RF signals may be used. In the third frequency converters 7011 to 701N,
As described in the fourth embodiment, the real part and the imaginary part of the baseband signal are output.

Outputs of the real part and the imaginary part of the third frequency converters 7011 to 701N are output from the first A / D converters 5011 to 5011N, respectively.
A / D conversion is performed at 501N. The oscillation frequency of the oscillator 702 is controlled by the automatic frequency converter controller 117 so that the center frequency at the output of the first transversal filter 107 becomes zero.

When this configuration is used, A / D conversion with a baseband signal may be performed, so that the power consumption of the A / D converter can be reduced.

Next, an eighth embodiment of the present invention will be described. In the eighth embodiment, a mode is adopted in which a propagation environment diagnostic device that determines whether the environment is a frequency selective fading environment is provided, and the configuration of the multiplier of the second weighting means is changed according to the propagation environment.

FIG. 14 is a diagram showing the configuration of the eighth embodiment of the present invention. Here, the same components as those described in FIGS. 1 to 13 are denoted by the same reference numerals, and description thereof will be omitted. In this figure, reference numeral 801
Is a propagation environment diagnostic device. The configuration of the complex coefficient multiplication circuit 802 used in this embodiment is as shown in FIG. 15, and the configuration of the real number coefficient multiplication circuit 803 is as shown in FIG.

FIG. 17 shows a signal processing flow in the propagation environment diagnostic apparatus 801, where an FFT operation (step S
100), determination of the presence or absence of a notch (step S101),
It consists of a circuit selection step (step S102).

[0100] The output signal of the first frequency converter 106 is input to the propagation environment diagnostic apparatus 801, and the frequency characteristic at the output of the first frequency converter 106 is obtained by performing Fourier transform. If the frequency characteristic is an environment having a notch in the transmission band, it is determined to be frequency selective fading, and waveform equalization in the first transversal filter 107 does not operate effectively. In the filter 107, the second weighting units 1090 to 109M are real numbers so that only the timing compensation is performed.

If no notch exists in the transmission band, it is determined that the frequency band is not frequency selective fading.
Since there is no long delay wave delayed by more than the symbol length, the first transversal filter 107
, The second weighting means 1090 to 109 so that the first transversal filter 107 has both functions of timing compensation and waveform equalization.
M is a complex number.

When the value of the weight of the second weighting means 1090 to 109M in the first transversal filter 107 is a complex number, a program for configuring the complex multiplying circuit 802 from the propagation environment diagnosing device 801 is digitally programmed. The signal is input to the signal processing unit, and the second weighting means 1090 to 1 in the first transversal filter 107
09M weighted complex multiplication.

The second weighting means 1090 to 1090
When the value of the 9M weight is a real number, a program for configuring the real number multiplication circuit 803 is input from the propagation environment diagnostic device 801 to the digital signal processing unit, and the second weighting in the first transversal filter 107 is performed. The weighting by means 1090 to 109M is a real number.

By using this configuration, when applied to a system in which the transmission rate is variable, the second weighting means is a real number at the time of high-speed transmission, so that the stable operation of the first transversal filter can be reduced. High power consumption is achieved, and high-quality transmission quality can be obtained in low-speed transmission by waveform equalization in both space and time.

Next, a ninth embodiment of the present invention will be described. In the ninth embodiment, of the optimal weight set of the second weighting means corresponding to the discrepancy of the identification timing, the set in which the amplitude variation error of the output signal is the smallest is set as the weight value of the second weighting means. Adopt a form that does.

FIG. 18 is a diagram showing the configuration of the ninth embodiment of the present invention. Here, the same components as those described with reference to FIGS. 1 to 17 are denoted by the same reference numerals, and description thereof will be omitted. FIG. 19 shows the configuration of the second weight control circuit 114 shown in FIG. 18, and reference numeral 901 indicates the output signal of the first transversal filter 107 when the weight set of the second weighting means is determined. A transmission quality estimating device for estimating a deviation of the amplitude from a desired discrete value, 902
Is the difference Δτ between the timing sampled by the first A / D converters 1031 to 103N and the optimum identification timing.
Second weighting means 1090 to 1090 corresponding to
This is a storage device in which sets of 9M weights are stored.

In the transmission quality estimating device 901, the first A / D converter 103 stored in the storage device 902 in advance with respect to the input signal of the first transversal filter 107.
Regarding the optimal set of weights of the second weighting means corresponding to the difference Δτ between the timing sampled at 1 to 103N and the optimal identification timing, the desired output level of the output signal of the adaptive antenna apparatus when each set is used. The following equation Q = E [| (y-d1) (y-d2) (yd-3)... |] Representing the deviation from the discrete value is used to estimate the value Q indicating the deviation. Is determined as the weight of the second weighting means. In the above equation, dn (n = 1, 2,..., L) represents a desired discrete value.

By using this configuration, even if a frequency error and a phase shift exist in the input signal to the first transversal filter 107, it is possible to stably determine the optimum weight.

Next, a tenth embodiment of the present invention will be described. In the tenth embodiment, the input signal to the beam forming circuit is an RF signal or an IF signal, and the frequency converter used when demodulating the output signal of the beam forming circuit and the characteristics of the first transversal filter are used. A mode in which a beam forming circuit is controlled using a signal demodulated for each antenna is employed.

FIG. 21 is a diagram showing the configuration of the tenth embodiment of the present invention. FIG. 22 shows the configuration of the first weight control circuit 111 shown in FIG.
Reference numeral 1001N denotes a fourth frequency converter, the configuration of which is as shown in FIG. Reference numerals 10021 to 10021
1002N is a second transversal filter,
The configuration is as shown in FIG. Reference numeral 1003 is a reference signal generator, and 1004 is a weight control circuit.

The signals x1 to xN received by the antenna elements 1011 to 101N are input to the first weight control circuit 111 as RF signals or after being converted into IF signals. Inside the first weight control circuit 111, input signals x1 to xN from the antenna elements 1011 to 101N are
The fourth frequency converters 10011 to 1001N and the second transversal filters 10021 to 1002N use the weight values of the second weighting means 1090 to 109M determined by the first transversal filter 107 to obtain the following. It is converted like an expression. Where x
n ′ is the output signal of the transversal filter operation unit,
M is the number of taps, cm tap coefficients, T _s / a represents a tap interval.

[0112]

[Equation 11]

When the weight values set in the first weighting means 1031 to 103N are w1 to wN, and the reference signal input from the reference signal generator is d, the square of the error is minimized. The value of the weight forming the directivity is given by (Equation 1). By operating in this way, it is possible to operate the adaptive antenna apparatus using the algorithm with the minimum square error even when data acquired at an arbitrary timing is used.

Next, an eleventh embodiment of the present invention will be described. In the eleventh embodiment, a form in which the beamforming circuit is converted to a baseband signal before A / D conversion, and the characteristics of the first transversal filter are used, and a signal demodulated for each antenna is used. adopt.

FIG. 23 is a diagram showing the configuration of the eleventh embodiment of the present invention. Here, the same components as those described with reference to FIGS. 1 to 22 are denoted by the same reference numerals, and description thereof will be omitted.

The signals x1 to xN received by the respective antenna elements 1011 to 101N are converted by the second frequency converter 2011 to xN.
The signal is converted into an IF signal at 201N,
011 to 701N, the baseband signal is separated into an in-phase component and a quadrature component.
11 to 501N and the first weight control circuit 111. The configuration of the third frequency converters 7011 to 701N is as shown in FIG.

In the first weight control circuit 111, input signals x1 to xN from each antenna are converted into first transversal signals by second frequency converters 2011 to 201N and a second transversal filter operation unit. Filter 1
Using the value of the weight of the second weighting means determined by 07, the conversion is performed as in (Equation 16). Assuming that the weight values set in the first weighting means are w1 to wN and the reference signal input from the reference signal generator is d, the weight for forming the directivity so that the square of the error is minimized. Is given by (Equation 1). By operating in this way,
2 when using data acquired at any timing
It is possible to operate the adaptive antenna device using the algorithm with the minimum squared error.

[0118]

According to the present invention, in the adaptive antenna apparatus of the present invention, the sampling clock for converting into a digital signal is set to an arbitrary frequency, and the timing is compensated by the transversal filter using real number weighting. In addition, the hardware scale can be reduced, and the feedback to the sampling clock is eliminated, so that the adaptive antenna apparatus can be stably operated even in an environment where the transmission quality is significantly deteriorated.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 shows first weighting means 1031 to 10 shown in FIG.
It is a figure which shows the structure of 3N.

FIG. 3 is a diagram showing a configuration of a first weight control circuit 111 shown in FIG. 1;

FIG. 4 shows second weighting means 1090 to 1090 shown in FIG.
It is a figure showing the composition of 9M.

FIG. 5 is a diagram illustrating a configuration of a first weight control circuit 111 according to a second embodiment of the present invention.

FIG. 6 shows second frequency converters 2011 to 20 shown in FIG.
It is a figure showing 1N composition.

FIG. 7 is a diagram showing a configuration of a third embodiment of the present invention.

FIG. 8 is a diagram showing a configuration of a fourth embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a third frequency converter 401 shown in FIG.

FIG. 10 shows a first weighting unit 1031 shown in FIG.
It is a figure showing composition of 103N.

FIG. 11 is a diagram showing a configuration of a fifth embodiment of the present invention.

FIG. 12 is a diagram showing a configuration of a sixth embodiment of the present invention.

FIG. 13 is a diagram showing a configuration of a seventh embodiment of the present invention.

FIG. 14 is a diagram showing a configuration of an eighth embodiment of the present invention.

FIG. 15 is a diagram showing a configuration of a complex coefficient multiplication circuit 802 used in the eighth embodiment.

FIG. 16 is a diagram showing a configuration of a real number coefficient multiplication circuit 803 used in the eighth embodiment.

FIG. 17 is a diagram showing a signal processing flow in the propagation environment diagnostic device 801.

FIG. 18 is a diagram showing a configuration of a ninth embodiment of the present invention.

19 is a diagram showing a configuration of a second weight control circuit 114 shown in FIG.

20 is a diagram showing a configuration of second transversal filters 10021 to 1002N shown in FIG.

FIG. 21 is a diagram showing a configuration of a tenth embodiment of the present invention.

FIG. 22 is a diagram illustrating a configuration of a first weight control circuit 111 illustrated in FIG. 21;

FIG. 23 is a diagram showing a configuration of an eleventh embodiment of the present invention.

FIG. 24 is a diagram illustrating a result of comparing characteristics of a transmission rate and an output SINR.

FIG. 25 is a diagram showing a configuration of a conventional adaptive antenna device.

FIG. 26 is a diagram showing a configuration of a conventional adaptive antenna device using a transversal filter.

FIG. 27 shows a first weighting means 14031 shown in FIG.
1403N and second weighting means 14070-14
It is a figure which shows the structure of 07M.

[Explanation of symbols]

1011 to 101N Antenna element 102 Analog beam forming circuit 1031 to 103N First weighting means 104 First combiner 105 First A / D converter 106 First frequency converter 107 First transversal filter 1081 to 108M Delay element 1900-109M second weighting means 110 second combiner 111 first weight control circuit 1121-112N second A / D converter 113 first digital signal processing device 114 second weight control circuit 115 First sampling clock generator 116 Second sampling clock generator 117 Automatic frequency converter controller 1181-1182 Real multiplier 119 Variable amplifier 120 Variable phase shifter 2011-201N Second frequency converter 202 Oscillator 203 Mixer 204 Low pass 01 Third frequency converter 4021 to 4022 Mixer 403 π / 2 phase shifter 4041 to 4042 Low-pass filter 5011 to 501N First A / D converter 502 Sampling clock generator 503 Digital beam forming circuit 5041 to 504N Multiplier 505 Real number subtractor 506 Real number adder 7011-701N Third frequency converter 702 Oscillator 801 Propagation environment diagnostic device 802 Complex coefficient multiplication circuit 803 Real number coefficient multiplication circuit 901 Transmission quality estimation device 902 Storage device 10011-1001N Fourth frequency conversion Devices 10021 to 1002N second transversal filter 1003 reference signal generator 1004 weight control circuit 13011 to 1301N antenna element 13021 to 1302N weighting means 1303 weight control device 1304 Reference signal generator 1305 Combiner 14011 to 1401N Antenna element 1402 Beam forming circuit 14031 to 1403N First weighting means 1404 First combiner 1405 Transversal filter 14061 to 1406M Delay element 14070 to 1407M Second weighting means 1408 Second Synthesizer 14091 to 14094 real number multiplier 1410 real number subtractor 1411 real number adder 1412 automatic frequency converter controller 1413 timing recovery circuit 14141 to 1414N A / D converter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kentaro Nishimori 2-3-1 Otemachi, Chiyoda-ku, Tokyo Within Nippon Telegraph and Telephone Corporation (72) Inventor Toshikazu Hori 2-3-1, Otemachi, Chiyoda-ku, Tokyo No. 1 Nippon Telegraph and Telephone Corporation F term (reference) 5J021 AA05 AA06 CA06 DB01 EA04 FA17 FA20 FA24 FA25 FA26 FA29 FA32 GA01 GA08 HA05 HA10 JA07 5J022 AA01 BA06 CA10 5K059 CC03 DD33 DD37 DD39 EE02 5K062 AA01 AB10 AC01 BE02

Claims (11)

[Claims] A plurality of antenna elements, an analog beam forming circuit connected to each of the plurality of antenna elements, and weighting and combining an input signal from each of the antenna elements by first weighting means; The output signal of the beam forming circuit is used as an input signal,
A first A / D converter that converts and outputs a digital signal, a first frequency converter that converts an input signal converted into a digital signal by the first A / D converter into a baseband signal, A plurality of delay elements having a fractional symbol length delay time are connected in series to the output of the first frequency converter, and the output of each delay element is weighted by the second weighting means, and the fractional symbol length interval to be combined is provided. The first transversal filter, and only the received signal at each antenna element, or both the received signal at each antenna element and the output signal of the first transversal filter as input signals, A / D-converts the input signal from the second digital-to-analog converter by a second A / D converter, and then the first digital signal processing device uses the value of the weight used in the first weighting means. A first weight control circuit that performs an operation, a second weight control circuit that receives an output signal of the first frequency converter as an input signal, and calculates a value of a weight used in the second weighting unit; An output signal of the transversal filter as an input signal, and a frequency converter automatic control device for controlling the first frequency converter so as to reduce a frequency conversion error in the first frequency converter; A first sampling clock generator for generating a first sampling clock in the A / D converter, and a second sampling clock generating for generating a second sampling clock in the second A / D converter Vessels,
The first sampling clock generator has a frequency that is at least twice the transmission rate, is not synchronized with the transmission rate, and has an interval substantially equal to the delay time of the delay element of the first transversal filter. Wherein the second sampling clock is not synchronized with the first sampling clock. 2. A second frequency converter is provided inside the first weight control device, and the second frequency converter converts an input signal from each of the antenna elements into an intermediate frequency signal. The adaptive antenna device according to claim 1, wherein: 3. A second frequency converter connected to each of the antenna elements and converting an input signal from each of the antenna elements into an intermediate frequency signal, wherein the second frequency converter is converted by the second frequency converter. 2. The adaptive antenna device according to claim 1, wherein a subsequent intermediate frequency signal is input to said first weight control device. A plurality of antenna elements; an analog beam forming circuit connected to each of the plurality of antenna elements, for weighting an input signal from each of the antenna elements by first weighting means and combining the signals; A first frequency converter for converting the output signal of the beam forming circuit into a baseband signal as an input signal, and a first A for converting the baseband signal from the first frequency converter to a digital signal and outputting the digital signal / D converter, and a plurality of delay elements having a delay time of a fractional symbol length are connected in series to the output of the first A / D converter, and the output of each delay element is weighted by the second weighting means. A first transversal filter with a fractional symbol length interval to be combined, and only the received signal at each antenna element, or the received signal at each antenna element After both the output signals of one transversal filter are input signals, and the input signals from the respective antenna elements are A / D-converted by the second A / D converter, the first digital signal processing device performs the above-described processing. A first weight control circuit for calculating a value of a weight used in the first weighting means, and an output signal of the first frequency converter as an input signal, and calculating a value of a weight used in the second weighting means. A second weight control circuit, an output signal of the first transversal filter being an input signal, and controlling the first frequency converter so as to reduce a frequency conversion error in the first frequency converter. A frequency converter automatic control device, a first sampling clock generator for generating a first sampling clock in the first A / D converter, and a second A / D converter. A second sampling clock generator for generating a second sampling clock in vessels,
The first sampling clock generator has a frequency that is at least twice the transmission rate, is not synchronized with the transmission rate, and has an interval substantially equal to the delay time of the delay element of the first transversal filter. Wherein the second sampling clock is not synchronized with the first sampling clock. 5. A plurality of antenna elements, a first A / D converter connected to each of the plurality of antenna elements, for converting an input signal from each of the antenna elements into a digital signal, A digital beam forming circuit for weighting and synthesizing a signal converted to a digital signal by the A / D converter by first weighting means; an output signal of the digital beam forming circuit as an input signal; A first frequency converter for converting the signal into a signal; a plurality of delay elements having a fractional symbol length delay time connected in series to an output of the first frequency converter; A first transversal filter with a fractional symbol length interval to be weighted and synthesized by means, and only the digital signal A / D converted by each of the first A / D converters, Rui A in the above first A / D converter /
A first digital signal processing device calculates a weight value used in the first weighting means by using both the D-converted digital signal and the output signal of the first transversal filter as input signals. And a second weight control circuit that uses the output signal of the first frequency converter as an input signal and calculates a weight value used by the second weighting means by a first digital signal processing device. A frequency converter automatic control device for controlling an output signal of the first transversal filter as an input signal to reduce a frequency conversion error in the first frequency converter; A first sampling clock generator for generating a first sampling clock in the converter;
The first sampling clock has a frequency of twice or more the transmission rate, is not synchronized with the transmission rate, and is sampled at substantially the same interval as the delay time of the delay element of the first transversal filter. An adaptive antenna device that oscillates in such a manner as to perform the following. 6. An intermediate frequency signal which is connected to each of said antenna elements and converts an input signal into an intermediate frequency signal, wherein said intermediate frequency signal is converted by said second frequency converter. The adaptive antenna apparatus according to claim 5, wherein? Is input to the first A / D converter. 7. A plurality of antenna elements, a first frequency converter connected to each of the plurality of antenna elements, and frequency-converting an input signal from the antenna elements into a baseband signal, A first A / D converter for converting a baseband signal from the converter to a digital signal, and a signal weighted by the first A / D converter to a digital signal by first weighting means. A digital beam forming circuit to be combined, a plurality of delay elements having a fractional symbol length delay time connected in series to the output of the digital beam forming circuit, and the output of each delay element is weighted by second weighting means;
A first transversal filter having a fractional symbol length interval to be combined, a digital signal converted by the first A / D converter only, or an A / D converted by the first A / D converter.
A first digital signal processing device calculates a weight value used in the first weighting means by using both the D-converted digital signal and the output signal of the first transversal filter as input signals. A second weight control circuit for calculating the value of the weight used in the second weighting means by using a first digital signal processing device with an output signal of the digital beam forming circuit as an input signal; A frequency converter automatic control device for controlling an output signal of the first transversal filter as an input signal so as to reduce a frequency conversion error in the first frequency converter; and a first A / D converter. A first sampling clock generator for generating a first sampling clock at
The first sampling clock has a frequency of twice or more the transmission rate, is not synchronized with the transmission rate, and is sampled at substantially the same interval as the delay time of the delay element of the first transversal filter. An adaptive antenna device that oscillates in such a manner as to perform the following. 8. A propagation environment diagnosis device for judging whether the environment is a frequency selective fading environment inside the second weight control circuit, wherein the second weighting is performed by the first transversal filter unit. The weighting of the second weighting means is set to a real number when frequency selective fading is performed by the means, and the weight of the second weighting means is switched to a complex number when not frequency selective fading. 8. The adaptive antenna device according to any one of items 7 to 7. 9. A modulation method in which an amplitude at a discrimination timing for judging a code is a discrete value, wherein the second weight control device comprises a timing at which an input signal is sampled by the first A / D converter. And a storage device storing an optimal set of weights of the second weighting means corresponding to the difference between the optimum timing for performing decoding and the optimum timing for decoding, and a weight of each second weighting means stored in the storage device. A transmission quality estimating device for estimating the deviation of the amplitude at the output of the first transversal filter from the discrete value, wherein a set of weights of the second weighting means stored in the storage device is provided. 2. The method according to claim 1, wherein a set in which the deviation of the amplitude of the output signal estimated by the transmission quality estimating device from the discrete value is minimized is set as the weight value of the second weighting means. ~ 8 The adaptive antenna device according to any one of the above. 10. The first digital signal processing device, wherein: a reference signal generating section for generating a reference signal d; and frequency conversion of an input signal from each of the antenna elements with the same characteristics as the first frequency converter. And a second transversal filter for converting an output signal of the fourth frequency converter with the same characteristics as the first transversal filter. The signal x′i (i = 1,...,...) Converted by the frequency converter and the second transversal filter.
The value of the first weighting means w _opt i (i = 1,..., N) is determined by the following equation with respect to (NN: number of elements). , 6, 8, and 9. (Equation 1) 11. The first digital signal processing device, wherein: a reference signal generating unit for generating a reference signal d; and frequency conversion of an input signal from each of the antenna elements with the same characteristics as the third frequency converter. And a second transversal filter for converting an output signal of the fourth frequency converter with the same characteristics as the first transversal filter. A signal x'i (i = 1,...,...) Converted by the frequency converter and the second transversal filter.
NN: The number of elements w _opt i (i = 1,..., N) of the first weighting means is determined by the following equation with respect to (N: number of elements). 10. The adaptive antenna device according to any one of 9. (Equation 2)