JP2002374191A - Device and method for adaptive equalization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that sufficient equalization can not be performed, if a signal of large electric power is present outside of the equalization range of an adaptive equalizer. SOLUTION: A received signal and a synchronous word signal are correlated with each other, and a window signal, having the same time width as the equalization range of the adaptive equalizer, is generated and shifted sequentially in time into #1, #2, #3, #3, etc., (Fig. 2B); and the sum of electric power of the correlation output signal (Fig. 2A) in each window signal is found, and the increase in the window signal which has the largest electric power sum is regarded as the symbol synchronization timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adaptive equalizer and a method for removing interference which can be used, for example, in mobile communications, and more particularly to a symbol synchronization timing generator for effectively performing adaptive equalization processing. And its method.

[0002]

2. Description of the Related Art An adaptive equalizer is a technique for removing interference in mobile communication. An adaptive equalizer is conventionally used to combine and remove intersymbol interference caused by delayed signals that are their own signals but are delayed in time by signal processing on the time axis. . A conventional example of a method for detecting a symbol synchronization timing of a received signal used in such an adaptive equalizer will be described below. In the conventional method, the symbol timing is synchronized with the preceding wave which is the earliest arriving path. FIG. 1 shows a configuration example in this case. Although not shown in the drawing, the transmitting side first transmits a long synchronization word signal whose transmission symbol pattern is known at the receiving side, and then transmits data indicating the information content to be transmitted. On the receiving side, although not shown in the drawing, the radio wave received from the transmitting side is amplified and demodulated to be a baseband signal, which is then converted to a digital sequence. , Sync word generator 1
The propagation path response is estimated by obtaining the correlation with the synchronization word signal from the second in the correlator 13. This propagation path response, that is, the output signal of the correlator 13 changes as shown in FIG. 2, for example, and the threshold signal Th from the threshold signal setter 14 is changed.
The symbol synchronization timing generator 15 compares s with the correlation output signal Sigc, detects the first timing t1 at which the correlation output signal Sigc exceeds the threshold signal Ths, and obtains the symbol synchronization timing of the preceding wave. The sampled signal is sampled in the sampler 16 by the digitized received signal from the input terminal 11 by the symbol synchronization timing signal, and the output signal is sampled by the adaptive equalizer 17.
The adaptive equalizer 17 performs adaptive equalization processing on the input sampling signal, and outputs a decision symbol signal to the output terminal 1.
8 is output.

[0003]

According to the conventional method for adjusting the symbol synchronization timing to the preceding wave, when the adaptive equalizer 17 whose equalization range is limited in time is used, the power is out of the equalization range. In some cases, there is a correlation output signal having a large value, and in this case, sufficient equalization cannot be performed, resulting in a problem that characteristics are deteriorated.

[0004]

According to the present invention, the correlation obtained from the correlator within a fixed time width of at least one symbol length or more, preferably more than a length substantially corresponding to the equalization range of the adaptive equalizer. The power sum of the output signal is calculated while shifting the fixed time width in time, and in one aspect of the present invention, the timing at which the power sum is maximized is detected, and the symbol synchronization timing is generated based on this timing. According to another aspect of the present invention, a timing at which the power sum first exceeds a threshold is detected, and a symbol synchronization timing is generated based on this timing.

[0005] With this configuration, the path power sum within the equalization range of the adaptive equalizer can be maximized, so that the equalization processing can be performed effectively. As a result, good reception characteristics can be expected.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment The structure of a first embodiment of the present invention is shown in FIG. 3 with parts corresponding to those in FIG. The correlator 13 outputs a correlation between the synchronization word signal generated by the synchronization word generator 12 and the signal received from the input terminal 11. At this time, as a synchronization word signal, which is used in the prior art, a symbol pattern having a high autocorrelation and a low cross-correlation with an interference wave, for example, a PN code sequence is used to obtain a symbol of a desired signal. Can detect timing,
In addition, the influence of the interference wave can be eliminated.

On the other hand, in this embodiment, the sum of the correlation outputs Sigc within a certain time width is obtained in the power measuring unit 22 while this time width is sequentially shifted in time. For example, a window signal generator 21 is provided, and the window signal generator 21 outputs a window signal having the same time width as the equalization range of the adaptive equalizer 17.
For example, when the equalization range is a delay of 4 symbols, a window signal is generated which becomes 1 during a time width 4T (T is a symbol period) and becomes 0 otherwise. This window signal and the correlation output signal Sigc from the correlator 13 are
To enter. The power measurement unit 22 sequentially calculates the power sum of the correlation output signal Sigc within the range of the window signal while shifting the temporal position of the window signal. This is shown in FIG. The baseband reception signal from the input terminal 11 is, for example, a sequence digitized by sampling at intervals of 1/16 of the symbol period T, and the synchronization word signal from the synchronization word generator 12 is also digitized at the same period. Therefore, the correlation output signal Sigc is also a digital sequence having the same period. FIG. 4A simply shows an example of the correlation output signal Sigc as a continuous waveform. As shown in FIG. 4B, the window signal # 1 having a level of 1 for the width of 4T in this example and 0 for the others in this example is sequentially shifted by the sampling period of the correlation output signal, in this example, T / 16. , # 3,..., And the sum of the correlation output signals Sigc when each of the window signals # 1, # 2, # 3,. That is, for the window signal # 1, the sum of the hatched portion in FIG. 4A in the correlation output signal is obtained.

As a specific example of the power measuring unit 22, for example, in the case of the above example in which the fixed time width is 4T and the sample period of the received signal is T / 16, as shown in FIG. 5A, a shift having 4 × 16 shift stages is used. At one end of the register 111, the correlation output signal S
igc, and the shift register 111 is set to T / 16
And the sum of the input and the output of each shift stage is obtained by the adder 112, the power sum in the window signal sequentially shifted by T / 16 is obtained for each T / 16. Alternatively, as shown in FIG.
The correlation output signal for each 16 is written into the memory 113. For example, when the writing of the correlation output signal corresponding to the end of the synchronization word signal is completed, the read address generator 114 outputs 4T.
The storage data is read from the memory 113 by generating a 4 × 16 address corresponding to the minute data, and the read 4 × 16 address is read.
The 16 data (correlation output signal) are added by the adder 115, and then shifted by one address, and the read address is set to 4 ×
The generation of 16 and the storage data of the memory 113 and the addition by the adder 115 may be repeated while shifting by one address. In this case, 4 × 16
The first data may be subtracted from the sum of the pieces of data and the data at the next address may be sequentially added. The reading may be performed in parallel before the writing to the memory 113 is completed.

The amount by which the window signal is shifted is determined by the correlation output signal S
igc is not limited to the sample period, but is an integral multiple thereof, for example, 2
It may be up to 4 times or larger. However, the accuracy of the required symbol synchronization timing increases as the deviation amount of the window signal decreases. In FIG. 3, the sampling clock used for digitizing the digital series received signal input to the input terminal 11 is transmitted from the sampling generator 19 to the synchronizing word generator 12, the window signal generator 21, and the power meter 22. Input and timed with each other.

However, when the power sum is obtained by using a shift register as described with reference to FIG. 5A, the window signal generator 2
1 is unnecessary. The symbol synchronization timing generator 23 generates the symbol synchronization timing using the timing at which the highest power is obtained from the sum of the powers output by the power measurement unit 22. In the case of the window signal as shown in FIG. 4, the rising timing of the window signal having the maximum power sum may be set as the symbol synchronization timing. In the above description, the time length (width) of the window signal, that is, the fixed time width for obtaining the power sum in the power measuring unit 22 is preferably the same time range as the equalization range of the adaptive equalizer 17. May be as short as one symbol period or longer, and the longer one may be as long as necessary. However, in practice, it is conceivable that the temporal range of the equalization range is about twice. Power measurement unit 2
The minimum number of power sums to be obtained in 2 is two, and the maximum is to obtain the power sum for window signals sequentially shifted from the generation to the end of the synchronization word signal. However, when the power sum obtained sequentially becomes equal to or less than a certain threshold value, and this state continues for a predetermined number of times, the calculation of the power sum is stopped, and the maximum power sum is selected from the power sum obtained up to that point. Is also good. It should be noted that, even when the sum of power is obtained, the sum of power obtained after the sum of power is equal to or larger than the threshold is regarded as valid, and the largest one is selected from the subsequent sums. Good.

The sampler 16 samples the received signal using the symbol synchronization timing signal. The adaptive equalizer 17 receives the sampling signal from the sampler 16 as input and performs equalization processing. FIG. 6 shows a configuration example of the adaptive equalizer 17. This configuration is MLSE (Maximum Likelihood S
This is called the “equence Estimation” type, which performs maximum likelihood sequence estimation and equalizes the received signal (for example, JG Proakis
^{: "Digital Communications 3 rd Edition,} " McGraw-
Hill pp. 249-254 (1995)). In this adaptive equalizer,
First, a symbol sequence candidate signal of the received signal is generated. If processing for band limitation or encoding is performed during transmission, a symbol sequence candidate signal is generated in consideration of these. Next, a parameter estimator 3 is added to the symbol sequence candidate signal.
The replica generator 32 performs a complex multiplication on the adaptive equalizer weighting coefficient output by 1 and combines the multiplication results to generate a replica of the received signal. Replica generator 3
FIG. 7 shows an example of the configuration of FIG. 7, which is composed of a plurality of complex multipliers 24 for complex multiplying the symbol sequence candidate signals by the adaptive equalizer weighting coefficients, respectively, and a complex adder 25 for adding these multiplication results. Also, each complex multiplier 24
Is output to the parameter estimator 31 as a tap input signal.

An adder 33 takes a difference between the replica signal and an input signal of the adaptive equalizer (output signal of the sampler 16) to generate an estimation error signal. Normally, the estimation error signal is squared by a squarer 34, and the squared value is used as a branch metric in a Viterbi algorithm for performing maximum likelihood sequence estimation by a maximum likelihood sequence estimator (MLSE) 35. Finally, the most probable symbol pattern obtained by the Viterbi algorithm is output to the output terminal 18 as a judgment symbol, and the received signal is demodulated. on the other hand,
The parameter estimator 31 updates the adaptive equalizer weighting coefficient using the estimation error signal and the tap input signal. An adaptive algorithm may be used for this update, and LMS (Le
ast Mean Square (RLS) algorithm and RLS (Recursive L
east Square) algorithm can be used (e.g., ^{JG Proakis: "Digital Communications 3 rd} Ed
, McGraw-Hill pp. 639-644, pp. 654-660 (199
5)). For the initial convergence of the adaptive equalizer weighting coefficients, a symbol pattern known as a training signal on the receiving side called a training signal is changed from a terminal 36 to a changeover switch 37 through a terminal 36 instead of the symbol sequence candidate signal from the MLSE processing unit 35. The data can be input to the replica generator 32 through the interface and used. Specifically, first, a training signal is used in place of the symbol sequence candidate signal to converge the adaptive equalizer weighting coefficient, and then the switch 37 is switched to the MLSE 35 side to demodulate the symbol using the symbol sequence candidate signal. Do. For an adaptive equalizer, see, for example, JG Proakis
^{: "Digital Communications 3 rd Edition,} " McGraw-
See Hill pp. 636-676 (1995).

As described above, in the first embodiment, the symbol synchronization timing generator 23 generates the synchronization timing such that the power within a fixed time width (window signal) is maximized. The path power that can be combined in the device 17 is maximized. As a result, as compared with the conventional symbol synchronization timing generator, it is advantageous in terms of a desired signal power to noise power ratio, and the reception characteristics can be improved. In addition,
The symbol synchronization timing generator 23 is not necessarily limited to a signal of one symbol period.
In the case of a linear equalizer having a transversal filter with a 1/2 symbol period interval, the sampler 1 has a 1/2 symbol period.
Sampling at 6 is performed. Second Embodiment The difference between the configuration of the second embodiment of the present invention and the first embodiment is as follows.
The difference lies in the method of measuring the power of the correlation signal in the power measuring unit 22. In the replica generator 32 in the adaptive equalizer,
As shown in FIG. 7, since the tap input signal is configured at a certain time interval, the received signal sampled at this time interval is equalized. Therefore, by determining the symbol synchronization timing in consideration of the tap interval of the replica generator 32, the path diversity effect can be more effectively obtained. The tap interval in the adaptive equalizer is often one symbol interval,
In this case, the power measuring method in the power measuring unit 22 is as follows.

The correlation output signal within the range of the window signal is sampled at each symbol interval, and the power sum of these sampling signals is calculated. This operation is repeated while shifting the temporal position of the window signal. For example, if the time width of the window signal in FIG. 4 is 4T, as shown in FIG.
The sum of the five sample values of the correlation output signal at the timings indicated by the three broken lines and the edges at # 2, # 3,... Is calculated. When calculating the power sum of the correlation output signal Sigc using the shift register shown in FIG. 5A, as shown in FIG.
Using the stage shift register 111, a shift operation is performed by the sampling clock Cs (the output of the sampling clock generator 19 in FIG. 3) to take in the correlation output signal Sigc. However, the input signal and the output of each of the 16 shift stages are added. The sum is added by the unit 112. The sum (power sum) is T / 16
Will be output every time.

In the symbol synchronization timing generator 23,
The timing which becomes the maximum in the sum of these powers is detected. With this method, it is possible to detect the timing at which the path diversity effect can be maximized even in an environment where the arrival paths of the received signal are distributed not only at symbol intervals but also at irregular intervals. The interval for summing the correlation output signals in the second embodiment may be the sampling interval by the sampler 16 in FIG. 3, and is not necessarily one symbol interval. Third Embodiment The configuration of a third embodiment of the present invention is shown in FIG. 9 by assigning the same reference numerals to parts corresponding to FIG. In this embodiment, as an adaptive equalizing means, a space-time equalizing configuration using both adaptive array antenna processing and adaptive equalizing processing is used.

An adaptive array antenna directs a beam having a relatively high antenna gain in the direction of a desired wave which is its own signal, and nulls a relatively low gain in the direction of an interference wave such as a signal of another user. A directional characteristic beam pattern to be directed is generated adaptively according to a change in signal condition. This is an effective technique for removing interference waves using the same frequency (channel), that is, co-channel interference. A space-time equalizer is a combination of the adaptive array antenna and the adaptive equalizer. For example, RT Compt
on, Jr .: “Adaptive Antennas-Concepts and Performa
nce, "Prentice-Hall, Englewood Cliffs (1988).

In the space-time equalizer, long delay waves and co-channel interference that cannot be equalized because they exceed the equalization range of the adaptive equalizer are removed by the adaptive array antenna, and the adaptive equalizer falls within the equalization range. Equalization processing is performed on a certain delayed wave. By adding equalization processing in the spatial domain in this way, even in a propagation environment where it is difficult to implement hardware due to an increase in the amount of computation only with signal processing in the time domain, equalization with a reasonable hardware scale Processing becomes possible. In FIG. 9, received signals from the respective elements of the adaptive array antenna are input to input terminals 11-1 to 11-N as baseband signals (digitized), and these N systems of received signals are samplers 16-1 to 16-1. 16
At −N, each is sampled by the symbol synchronization timing signal, and the generated N-system sampling signals are input to the adaptive equalizer 41, where equalization processing is performed. FIG. 10 shows a configuration example of the adaptive equalizer 41 in this embodiment. The difference from the adaptive equalizer shown in FIG. 6 is that an adaptive array antenna processing / combining unit 51 is provided. The sampling signals of the N systems from the terminals 52-1 to 52-N are combined by the adaptive array antenna processing / combining unit 51, and the combined signals are subjected to equalization processing. Adaptive array antenna processing / synthesizing section 51
FIG. 11 shows an example of the configuration. N complex multipliers 53-1 to 53-N for complexly multiplying N sampling signals from terminals 52-1 to 52-N and N adaptive array antenna (AAA) weighting coefficients, respectively, Complex adder 5 in which the outputs of the complex multipliers are complex-added
4. The weighting coefficients used in the adaptive array antenna processing / combining unit 51 are obtained by the parameter estimator 55.
It can be calculated using the second tap input signal which is the input of 53-N. For example, Ryuji Ko
hno: “Spatial and Temporal Communication Theory U
sing Adaptive Antenna Array ”, IEEE Personal Commu
nications, pp. 28-35, Feb. 1998, AJ Paulraj and
BC Ng, “Space-Time Modems for Wireless Personal
Communications ”, IEEE Personal Communications, p
See p. 36-48, Feb. 1998.

In this embodiment, there are N received signals, but it is sufficient if the correlation with the synchronizing word signal is obtained by the correlator 13 using any one of the received signals. However, the correlation between the plurality of received signals and the synchronization word signal is obtained, and the correlation output signals are added and averaged, for example, so that the correlation output signal can be obtained with higher accuracy. Fourth Embodiment FIG. 12 shows the configuration of a fourth embodiment of the present invention. The components other than the power comparator 61 and the symbol synchronization timing generator 62 are the same as those in the first and second embodiments shown in FIG. The power comparator 61 compares the power sums obtained by the power measurement unit 22, and selects L timing points (L is an integer of 1 or more) in descending order. When L is 1,
This embodiment is the same as the first embodiment. The maximum value of L is the number of power sums obtained by the power measurement unit 22, but may be set in consideration of the hardware scale. The symbol synchronization timing generator 62 outputs a symbol synchronization timing signal in accordance with the timing of each of the selected L power sums. In this embodiment, the sampler 16-1 corresponding to the L symbol synchronization timing signals
16-L, and each sampler 16-1 to 16-1
In 6-L, the received signal from the input terminal 11 is sampled by each of the L symbol synchronization timing signals from the symbol synchronization timing generator 62. The adaptive equalizer 63 performs an equalization process using these L sampling signals.

FIG. 13 shows a configuration example of the adaptive equalizer 63 in this case. The sampling signals from the samplers 16-1 to 16-L are input from terminals 64-1 to 64-L to the estimation error output units 65-1 to 65-L, respectively. As shown in the estimation error output section 65-1, the parameter estimator 31-1, the replica generator 32-1, and the parameter estimator 31-1 have the same configuration as that shown in FIG.
It includes an adder 33-1 and a squarer 34-1. The other estimation error output units 65-2 to 65-L also include a parameter estimator, an adder, a squarer, and a replica generator corresponding to each symbol synchronization timing. Have. In this example, the replica generation and the parameter estimation are performed at every L symbol synchronization timings, and the square values of the estimation error signals of the respective adders are all added by the adder 66 to obtain a branch metric.
The MLSE processing unit 35 performs the MLSE processing. ML
Other adaptive equalization processing may be performed instead of the SE processing unit 35.

As shown in FIG. 14, each of the estimated error output units 65-1 to 65-L has an MLSE processing unit 35-
After performing equalization processing independently for each symbol synchronization timing, the quality corresponding processing unit 67 outputs the output of each of the MLSE processing units 35-1 to 35-L. It is also possible to adopt a configuration in which a process according to the communication quality is performed to obtain a final output. In this case, as a process according to the communication quality, for example, a method in which the majority decision is made by the majority decision unit 69 using the obtained equalizer output (MLSE process output) as shown by a broken line in the drawing, The outputs when the MLSE processing units 35-1 to 35-L respectively output and the adders 33-1 to 3 corresponding to the outputs.
A weight corresponding to the magnitude of the square of each error signal of 33-L,
The outputs from the MLSE processing units 35-1 to 35-L are added to each other and added by an adder 68, and the added signal is binarized by a threshold circuit 68a and output. In the latter case, the one with a smaller estimation error may be regarded as having good communication quality and a large weight may be given.

It is also possible to use an adaptive array antenna processing / combining unit as in the third embodiment. FIG. 15 shows a configuration example in this case. Input terminals 11-1 to 11
−N are sampled by the samplers 1-1 to 1-N according to the first symbol synchronization timing signal from the symbol synchronization timing generator 62, respectively, and are sampled according to the second symbol synchronization timing signal.
2-N, are sampled by the samplers L-1 to L-N according to the N-th symbol synchronization timing signal, and are input to the adaptive equalizer 71.

In the adaptive equalizer 71, the outputs of the samplers 1-1 to 1-N are input to the estimation error output section 72-1 as shown in FIG. 16, and the estimation error output section 72-1 is shown in FIG. Similarly to the configuration, the replica generator 32-1, the error calculation adder 33-1, the error squarer 34-1, the adaptive array antenna processing / synthesizing unit 51-1 and the parameter estimator 55-
1 Outputs of the samplers 2-1 to 2-N to outputs of the samplers L-1 to LN are input to the estimation error output units 72-2 to 72-L, respectively. Estimation error output unit 72
Each of -2 to 72-L has the same configuration as the estimation error output unit 72-1. Estimation error output units 72-1 to 72
−L is added by the adder 66 to obtain the ML
It is input to the SE processing unit 35.

By using the adaptive array antenna, a path outside the equalization range of the adaptive equalizer can be removed, and the reception characteristics can be further improved. In the above description, it is assumed that L systems are prepared for necessary parts.
It can be realized with a smaller value than that, and the hardware scale can be reduced. As described above, in this embodiment, by using a plurality of symbol synchronization timings, more paths can be combined, so that the reception characteristics are improved. Fifth Embodiment In a fifth embodiment of the present invention, in the power comparator 61 shown in FIGS. 12 and 15, when generating the symbol synchronization timing as in the fourth embodiment, L powers are simply fixed in descending order of the power sum. Instead of selecting the timing of
As shown in A, the threshold value Th is set in advance in the threshold value setting device 70, and Q powers exceeding the threshold value Th (Q is 1 < Q < L) are detected by the power comparator 61 during the power sum from the power measurement unit 22. < M
-Q number of symbol synchronization timings are generated based on the integers satisfying the following. By this operation, the value of Q is adaptively selected according to the communication situation. For example, although the power sum is within the Lth from the top, even if the equalization processing is performed, the effect of improving the reception characteristics is small. It is possible to omit the equalization processing for the symbol synchronization timing obtained from the window signal having a very small power sum, and as a result, it is possible to reduce the calculation amount of the entire equalization processing. In other words, the selection of L timings in the claim means that L is not a predetermined value but the number of power sums equal to or greater than the threshold value.

Further, even when a power sum in a window signal capable of exhibiting a sufficient reception characteristic at the top several points among the selected L points can be obtained, equalization of the symbol synchronization timing based on a power sum less than that. By omitting the processing, it is possible to reduce the amount of calculation in the equalization processing without substantially deteriorating the reception characteristics. That is, if the number of power sums exceeding a relatively large threshold is a predetermined number (for example, 1 or 2), equalization processing is performed only for symbol synchronization timing based on the power sum exceeding the threshold. . For example, as shown in FIG. 17B, the M power sums from the power measurement unit 22 are used as power comparators 61a, 61b, 6 respectively.
1c respectively supplied to the threshold values Tha, Thb, Th
c (Tha>Thb> Thc), and each of the power comparators 61a, 61b, and 61c outputs a value exceeding the threshold value in the M input power sums.
a, the threshold value Tha is set to such an extent that one or two power sums are output even if the reception condition is good, and three or four power outputs are output from the power comparator 61b, and the comparator 61c
In this case, another threshold value is selected so that 5 to 7 signals are output. The output of the power comparator 61b is supplied to the prohibition gate 121. The prohibition gate 121 is prohibited by the output exceeding the threshold from the power comparator 61a. The output of the power comparator 61c is supplied to the prohibition gate 122, and the prohibition gate 122.
Are prohibited by the output exceeding the threshold value from the power comparator 61b. Power comparator 61a, prohibition gates 121 and 12
2 is input to the symbol synchronization timing generator 62, and outputs a symbol synchronization timing signal having a timing corresponding to each input power sum.

In this embodiment, since the value of Q fluctuates,
There is a problem of how many replica generators and parameter estimators are to be prepared. However, if there is enough hardware, prepare a sufficient number, and if the value of Q is small, use some of them. There is a way to do it. In this case, there is a merit that power consumption can be reduced as compared with the case where all are operated. When the hardware scale is to be reduced, as described in the fourth embodiment,
What is necessary is just to use a replica generator, a parameter estimator, etc. by time division. Sixth Embodiment FIG. 18 shows a functional configuration of a sixth embodiment of the present invention. This embodiment has a configuration including two symbol synchronization timing generators. That is, in addition to the symbol synchronization timing generator 23 which generates the symbol synchronization timing signal at the timing when the power sum from the power measurement unit 22 shown in FIG. 3 becomes maximum, the conventional symbol synchronization timing generator 15 shown in FIG. And the correlation output signal is set to the threshold signal setting unit 14
, The symbol synchronization timing is generated from the timing of the preceding wave of the received wave.

These symbol synchronization timing generators 15
, And 23 are switched by the timing selector 81 and supplied to the sampler 16. In this embodiment, adaptive equalization processing is performed, for example, on a sampling signal at each symbol synchronization timing in a time-division manner, and it is determined which symbol synchronization timing signal is to be demodulated according to communication quality. As the communication quality, for example, using the estimated error signals in the last symbol of the training signal section by each symbol synchronization timing signal, comparing the magnitudes of these error signals, and performing demodulation processing at the timing when the estimated error power becomes small. As you do,
What is necessary is just to control the timing selector 81. Seventh Embodiment FIG. 19 shows a functional configuration of a seventh embodiment of the present invention, in which parts corresponding to those in FIG. In this embodiment, the power measuring unit 91 sequentially outputs the power sums of the correlation output signals in the sequentially shifted window signals # 1, # 2, # 3,... As shown in FIG. The signal is input to the timing generator 92, and the symbol synchronization timing generator 92 generates the window signal when the input power sum first exceeds the threshold signal set in the threshold signal setter 93. A symbol synchronization timing signal is generated based on the timing. The rest is the same as the configuration shown in FIG. Also in the seventh embodiment, the sum of the powers of the correlation output signals may be the sum of those sampled at the sampling interval of the sampler 16. Eighth Embodiment As shown in FIG. 20A, the arrival path of a radio wave is divided into several groups G1, G2,.
0B, the received signals G1 ', G1
In the propagation path environment where the delay times of 2 ′,.
In the configuration shown in (including the embodiment), when the number of taps of the adaptive equalizer is small, it may not be possible to obtain sufficiently good reception characteristics. In this embodiment, the equalization process can be effectively performed even in such a propagation environment.

FIG. 21 shows the structure of the eighth embodiment, in which parts corresponding to those in FIG.
In this embodiment, in addition to the configuration used in the second embodiment, N-ary array antenna reception signals are input to input terminals 11-1,.
−N, and P is input by the multi-beam generator 101.
, 16-P, and outputs P-system beam reception signals to P-system correlators 13-1,..., 13-P, and P-system samplers 16-1,.
.., 13-P and the received signal of each beam and the sync word generator 1
., 22-P, the correlation output signals of the respective correlation output signals within the range of the window signal from the window signal generator 21 are calculated by the power measurement units 22-1,. Each of the power sums is calculated, and these calculations are performed by sequentially shifting the time position of the window signal. Each of the power sums sequentially output from the power measuring units 22-1,.
,..., 23-P, and in each of the symbol synchronization timing generators 23-1,..., 23-P, the symbol synchronization is performed using the timing of the window signal having the largest power in the power sum. A timing is generated, and at that timing, the reception signals of the corresponding beams of the samplers 16-1,..., 16-P are sampled. The sampled outputs of the samplers 16-1,..., 16-P are supplied to the adaptive equalizer 105.

FIG. 2 shows an example of the configuration of the multi-beam generator 101.
It is shown in FIG. As with the adaptive array antenna shown in FIG. 11, each antenna reception input terminal 11-1,.
-N, the multipliers 102-1,..., 10
The multiplication results are multiplied by 2-N, and the multiplication results are added up by the adder 103-1 to obtain an output signal of one of the multi-beams. By updating the weighting coefficient adaptively according to the arrival situation of the adaptive array antenna shown in FIG. 11, one beam output signal is output, while the multi-beam generator 1
In step 01, a received signal of one beam in a fixed direction is output using a weighting coefficient obtained in advance irrespective of the arrival state of the signal.
The difference is that a plurality of 1,..., 104-P are provided. As described above, in the multi-beam generator 101, the P-system beams are converted into the beamformers 104-1,
, 104-P, but their beams are
The directions of the main beams are different from each other. For example, as shown in FIG. 23, normally, all the beams G1,..., GP are used so as to cover all the radio wave arrival directions. A beam having such properties is, for example, Butl
It can be easily generated by using the er Matrix circuit. FIG. 23 shows an example of a multi-beam formed using a Butler Matrix circuit (for example, J. Ltva an
d TK Lo: “Digital Beamforming in Wireless Commun
ications, ”Artech House, Boston London pp. 22-34,
(1996)).

, GP 'of the P-system multi-beam reception signals G1',..., GP 'obtained by the multi-beam generator 101.
Are the correlators 13-1,..., 1 as described above.
3-P, through the power measuring units 22-1,..., 22-P,
Symbol synchronization timing generators 23-1,..., 23-P
To generate P symbol synchronization timing signals. Using the P symbol synchronization timing signals, samplers 16-1,..., 16-P generate P-system sampling signals from P-system beam reception signals G1 ',. That is, in each of the symbol synchronization timing generators 23-1,..., 23-P, as shown in FIG. The timing at which each power sum is the largest is the symbol synchronization timing. In FIG. 21, a correlator, a power measuring unit, a symbol synchronization timing generator, and a sampler are prepared for each beam system, but these units may be used in each system in a time division manner.

The P-system sampling signal generated in this manner is input to the adaptive equalizer 105, where the signal is equalized. FIG. 25 shows a configuration example of the adaptive equalizer 105 in this embodiment, and portions corresponding to those in FIG. 10 are denoted by the same reference numerals. The sampled signals of the P system from the samplers 16-1,..., 16-P are weighted by the linear combiner 106 and then combined, and the combined signal is subjected to equalization processing. The contents of the equalization processing are the same as in the third embodiment. That is, the linear synthesizer 106 in this case is the adaptive array antenna processing / combining unit 51 in FIG.
And corresponding. The weighting coefficient for the linear synthesizer 106 may be fixed.

As described above, by detecting the symbol synchronization timing for each beam of the multi-beams in different directions, it is possible to detect the symbol synchronization timing using not only the time domain but also the spatial domain as shown in FIG. Becomes possible. As in the example of the path of the incoming radio wave shown in FIG.
In the case where the delay times of the received signals are greatly different among the arrival path groups G1,..., GP and are spatially separated,
By separating the received signal in the spatial domain and detecting the symbol synchronization timing for each separated received signal, it is possible to obtain sufficiently good reception characteristics even when the equalization range of the adaptive equalizer 105 is small.

The multi-beam generator 1 shown in FIG.
01, the method of performing symbol synchronization according to the present invention for a received signal for each beam can also be applied to the first to seventh embodiments described above. When using L timings having a large sum power as shown in FIG. 12, L samplers are provided for each of the samplers 16-1,..., 16-P in FIG. .., 11-N are supplied with the P output signals from the multi-beam generator 101, respectively. The configuration of the adaptive equalizer 105 is shown in FIG. A configuration similar to that shown in FIG. Ninth Embodiment As shown in FIG. 26A, radio waves are transmitted through a plurality of paths G1,.
26B, the received signal G1 'of the path having relatively large received power among them arrives later in time than the received signals G2',..., GP 'of the other paths as shown in FIG. 26B. Consider the propagation path environment. In this case, in the configurations shown in the first to eighth embodiments, the symbol synchronization timing is adjusted so that the reception signal G1 'of one path having a large power falls within the window signal, and the reception signal G2' of the other path. ,
.., GP 'exist outside the equalization range T _AER .
As a result, the power within the equalization range T _AER is maximized, but since there is only one path, a sufficient path diversity effect cannot be obtained, and good reception characteristics may not be obtained in a fading environment. In this embodiment, good reception characteristics can be obtained even in such a propagation environment.

FIG. 27 shows the functional configuration of the ninth embodiment.
2 are denoted by the same reference numerals. This fruit
In this embodiment, the power measuring unit 22 used in the first to eighth embodiments is replaced.
Instead, a power dispersion value measuring unit 131 is used.
ing. The power variance value measuring unit 131 is configured to
Window signal and output from the threshold signal setting unit 132
The threshold signal Pth is input and 1
Measure the correlation output signal power for each sample and average the power
Value P_NIs calculated by the average value calculation unit 131a, and the power distribution
Value σ^TwoIs calculated by the variance value calculation unit 131b. Calculated
Power average value P_NIs greater than the threshold signal Pth,
Power dispersion value σ corresponding to that determined by comparison section 131c
^Two, For example, in order of small variance (K is an integer of 1 or more)
) Is selected and output by the variance comparison unit 131d. The value of K is
What is necessary is just to determine in consideration of a hardware scale. Note
The sample value of each correlation output signal in the signal is x (n), the window signal
Where N is the number of samples in the variance σ^TwoIs σ^Two= (1 /
N) Σ_n-1 ^N(X (n) -P _N)^TwoRequired by

The power variance value σ ² output by the power variance value measuring section 131 is input to the symbol synchronization timing generator 133, and the timing corresponding to each of these K power variance values σ ² , for example, the corresponding window A symbol synchronization timing signal is output based on the rising timing of the signal. For example, when the variance value in the window signal is 0, it indicates that the path exists at equal power at each sample point in the window signal, and the maximum path diversity effect can be obtained by adaptive equalization processing. Can be. The symbol synchronization timing signal is generated by the above process, and the samplers 16-1 to 16-16
−K generates a sampling signal of the received signal,
These sampling signals are input to the adaptive equalizer 63,
An equalization process is performed. Adaptive equalizer 6 in this embodiment
The configuration of 3 can use the same configuration as that shown in FIGS.

As described above, by using the ninth embodiment, it is possible to detect the symbol synchronization timing at which the number of paths exists within the equalization range, although the combined signal power is not always the maximum, and the path diversity is achieved. Due to the effect, good reception characteristics can be expected even in a fading environment. Tenth Embodiment As shown in FIG. 28, the tenth embodiment is different from the sixth embodiment shown in FIG. 18 in that the power dispersion value measuring unit 131 shown in FIG.
Is added. The two symbol synchronization timing generators 15 and 23 in the sixth embodiment
In addition to (62 in FIG. 12), a third symbol synchronization timing generator 133 is provided. Each symbol synchronization timing signal from the symbol synchronization timing generators 15, 62 and 133 is switched by the timing selector 81 and supplied to the samplers 16-1 to 16-L (or 16-K). Samplers are prepared by the larger of L and K.

As in the sixth embodiment, adaptive equalization processing is performed, for example, in a time-division manner at each synchronization timing, and the timing selector 81 is controlled to determine which symbol synchronization timing signal to use based on communication quality. decide. As a result, it becomes possible to detect a symbol synchronization timing that is more suitable for the propagation environment, and it is possible to expect improvement in reception characteristics. FIG. 2
8, one of the power measuring unit 22, the power comparator 61 and the symbol synchronization timing generator 62, and one of the threshold signal setting unit 14 and the symbol synchronization timing generator 15 may be omitted.

According to the ninth and tenth embodiments,
Even in a propagation path environment in which a radio wave arrives in multiple paths, and a path having relatively large received power arrives at a time distant from other paths, the adaptive equalizer can further obtain a path diversity effect. The symbol synchronization timing can be detected, and the reception characteristics can be improved. The second embodiment is applied to each of the seventh to ninth embodiments, and the power measurement unit 91 or the power dispersion measurement unit 131 converts the correlation output signal within the range of the window signal into the sampler 16 or 16. The sampling may be performed at every sampling interval of −1 to 16-P, and the power sum or the power variance of these sampling signals may be calculated. Also in the sixth, seventh, ninth, and tenth embodiments, the adaptive equalizer 17 performs adaptive array antenna processing and adaptive equalization processing similarly to the third embodiment. A space-time equalization configuration may be used in combination. Further, similarly to the sixth embodiment, the seventh embodiment,
The eighth embodiment may be combined with the conventional symbol synchronization timing generator 15 shown in FIG. 1 to selectively use both symbol synchronization timing signals according to communication quality. When K is plural in the ninth and tenth embodiments, the adaptive equalization processing shown in FIG. 13 or 14 may be performed. The ninth and tenth embodiments can also be applied to the multi-beam reception as shown in the eighth embodiment.

Each of the above-described embodiments can be operated by causing a computer to execute a program.

[0039]

As described above, according to the present invention, it is possible to detect the symbol synchronization timing at which the equalization processing in the adaptive equalizer can be performed more effectively, and the reception characteristics can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a functional configuration of a conventional adaptive equalizer.

FIG. 2 is a waveform chart showing an example of a correlation output signal and detection timing in a conventional symbol timing means.

FIG. 3 is a diagram showing a functional configuration of the first embodiment of the present invention.

FIG. 4 is a waveform chart showing an example of the relationship between a correlation output signal and a window signal used in the present invention.

5A is a diagram showing a specific example of a power measuring unit 22 in FIG. 3, and FIG. 5B is a diagram showing another example.

FIG. 6 is a diagram illustrating a functional configuration example of an adaptive equalizer 17 (MLSE-type adaptive equalizer) in FIG. 3;

FIG. 7 is a diagram illustrating a configuration example of a replica generator 32 in FIG. 6;

FIG. 8 shows a power measuring unit 22 according to a second embodiment of the present invention.
The figure which shows the specific example of.

FIG. 9 is a diagram illustrating a functional configuration example of a third embodiment of the present invention.

FIG. 10 is a diagram illustrating a functional configuration example of an adaptive equalizer 41 in FIG. 9;

11 is a diagram illustrating a configuration example of an adaptive array antenna processing / combining unit 51 in FIG. 9;

FIG. 12 is a diagram illustrating a functional configuration example of a fourth embodiment of the present invention.

FIG. 13 is a diagram illustrating a functional configuration example of an adaptive equalizer 63 in FIG. 12;

14 is a diagram illustrating another example of the functional configuration of the adaptive equalizer 63 in FIG.

FIG. 15 is a diagram illustrating an example of a functional configuration when an adaptive array antenna processing / synthesizing unit is used in a fourth embodiment.

16 is a diagram illustrating an example of a functional configuration of an adaptive equalizer 71 in FIG.

17A is a functional configuration diagram illustrating an example of detecting timing based on a power sum equal to or greater than a threshold, and FIG. 17B is a functional configuration diagram illustrating an example of detecting a number of timings according to the magnitude of the power sum. .

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

FIG. 19 is a diagram showing a functional configuration of a seventh embodiment of the present invention.

FIG. 20A is a diagram illustrating an example of a state in which radio wave arrival paths are divided into groups in different directions, and FIG. 20B is a diagram illustrating an example in which delay times of received signals differ greatly between paths in different directions.

FIG. 21 is a diagram showing a functional configuration of an eighth embodiment of the present invention.

FIG. 22 is a diagram showing a specific example of a multi-beam generator 101 in FIG. 21.

FIG. 23 is a diagram showing an example of a multi-beam.

FIG. 24 is a diagram showing an operation of generating symbol synchronization timing in the embodiment shown in FIG. 21.

FIG. 25 is a diagram showing a specific functional configuration example of an adaptive equalizer 105 in FIG. 21;

26A is a diagram showing an example of a state in which the radio wave arrival paths are divided in different directions, and FIG. 26B is a diagram showing a case where one path has a large received power, and a plurality of paths with small received power having greatly different delay times. FIG.

FIG. 27 is a diagram showing a functional configuration of a ninth embodiment of the present invention.

FIG. 28 is a diagram showing a functional configuration of a tenth embodiment of the present invention.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tadashi Matsumoto 2-1-1-1, Nagatacho, Chiyoda-ku, Tokyo F-term in NTT DoCoMo, Inc. (reference) 5K046 AA05 EE06 EF53

Claims (26)

[Claims] 1. A synchronization word generator for outputting a synchronization word signal of the same signal sequence as a synchronization word transmitted by a transmitter, a synchronization word signal and a reception signal, and a correlation between the reception signal and the synchronization word signal. A correlator that calculates and outputs the correlation value as a correlation output signal; and a power measurement that receives the correlation output signal as input and obtains the power sum of the correlation output signal within a fixed time width while shifting the time width in time. And the power sums obtained by the power measurement unit are compared by a predetermined reference to select timings at which L power sums (L is an integer of 1 or more) are obtained, and the selected L timings are selected. A symbol synchronization timing generator that generates and outputs a symbol synchronization timing signal, based on the L, and a sampler that samples a received signal using each of the L symbol synchronization timing signals. If, as input a received signal the sampling, the adaptive equalizer comprising an adaptive equalizer for outputting a decision symbol signal by processing adaptive equalization. 2. The power comparator according to claim 1, further comprising: a power comparator that receives the power sum from the power measurement unit and outputs a timing at which a power sum greater than a threshold is obtained to the symbol synchronization timing generator. An adaptive equalizer, comprising: 3. The apparatus according to claim 2, wherein a plurality of the thresholds are set, and the timing at which only the power sum exceeding the largest value among the power sums exceeding these thresholds is obtained is determined by the symbol synchronization. An adaptive equalizer comprising a power comparator for outputting to a timing generator. 4. A synchronizing word generator for outputting a synchronizing word signal having the same signal sequence as a synchronizing word transmitted by a transmitter, a synchronizing word signal and a receiving signal being input, and calculating a correlation between the receiving signal and the synchronizing word signal. A correlator that outputs the correlation value as a correlation output signal, and a power measurement unit that receives the correlation output signal as input, and obtains the power sum of the correlation output signal within a fixed time width while shifting the time width in time. A symbol synchronization timing generator that detects a timing when the magnitude of the power sum obtained by the power measuring device first exceeds the threshold value and generates and outputs a symbol synchronization timing signal based on the timing; A sampler for receiving a signal and sampling a received signal, and a received signal sampled by the sampler as an input and performing adaptive equalization processing To determine the adaptive equalizer comprising an adaptive equalizer for outputting a symbol signal. 5. A synchronizing word generator for outputting a synchronizing word signal of the same signal sequence as a synchronizing word transmitted by a transmitter, a synchronizing word and a receiving signal being input, and calculating a correlation between the receiving signal and the synchronizing word; A correlator that outputs the correlation value as a correlation output signal, and a correlation output signal and a threshold signal as inputs, and calculates an average value and a variance value of the correlation output signal within a fixed time width while shifting the time width in time. And K variance values at the timing when the average value is larger than the threshold signal (K is an integer of 1 or more)
An output power variance measurement unit, a symbol synchronization timing generator that generates K symbol synchronization timing signals based on the K timings, and a reception signal using the K symbol synchronization timing signals. An adaptive equalizer including: a sampler for sampling; and an adaptive equalizer that receives the sampled received signal as input, performs adaptive equalization processing, and outputs a determination symbol signal. 6. The apparatus according to claim 1, wherein a second symbol synchronization timing generator for generating a symbol synchronization timing signal based on the timing of the preceding wave, and a symbol synchronization timing signal from the symbol synchronization timing generator. An adaptive equalizer, comprising: a timing selector that adaptively switches between a symbol synchronization timing signal from the second symbol synchronization timing generator according to communication quality and supplies the signal to the sampler. 7. The power measuring unit according to claim 5, wherein the correlation output signal is input, and a power measuring unit that obtains the power sum of the correlation output signal within the fixed time width while shifting the power in time, and the power measuring unit. The respective timings at which L power sums (L is an integer of 1 or more) selected from the power sums obtained by the measurement unit are obtained, and a symbol synchronization timing signal is generated and output based on these L timings. A second symbol synchronization timing generator, a symbol synchronization timing signal from the symbol synchronization timing generator, and a symbol synchronization timing signal from the second symbol synchronization timing generator. An adaptive equalizer, comprising: a timing selector for supplying the sampler. 8. The apparatus according to claim 1, wherein the power measuring section or the power variance value measuring section samples a correlation output signal within the fixed time width at a sampling cycle of the sampler, and performs sampling. An adaptive equalizer, comprising a configuration for obtaining a power sum or a variance value of a selected signal. 9. The apparatus according to claim 1, wherein the adaptive equalizer is a space-time equalizer that performs signal processing in a space domain together with equalization processing in a time domain. Adaptive equalizer. 10. The apparatus according to claim 1, wherein said L or K is plural, and said adaptive equalizer outputs an error signal power between each of said plurality of sampled received signals and each replica signal. An adaptive equalizer, comprising: an estimation error output unit that outputs an error signal power; and an adaptive equalization processing unit that adds the error signal powers of these estimation error output units and inputs the error signal power. 11. The apparatus according to claim 1, wherein said L or K is plural, and said adaptive equalizer includes an adaptive equalization processing unit performed on said plurality of sampled received signals. And a final processing unit for performing a process according to the communication quality on the output from the adaptive equalization processing unit to obtain a final output. 12. The apparatus according to claim 1, 4 or 5, wherein weights are respectively applied to reception signals from a plurality of antennas to form a multi-beam antenna directional characteristic, and reception of each of the multi-beams is performed. A multi-beam generator that outputs a signal to the sampler, and the correlator, the power measurement unit or the power dispersion value measurement unit, and the symbol synchronization timing generator for each reception signal from the multi-beam generator, An adaptive equalizer, wherein a symbol synchronization timing signal from the symbol synchronization timing generator is supplied to the sampler to which a corresponding beam reception signal is supplied. 13. A process of generating a synchronization word signal having the same signal sequence as a synchronization word transmitted by a transmitter, a process of calculating a correlation between a received signal and the synchronization word signal, and using the correlation value as a correlation output signal. And calculating the power sum of the correlation output signal within a fixed time width while shifting the time width in time. Comparing the power sum according to a fixed criterion and calculating L (L is an integer of 1 or more) Selecting and generating a symbol synchronization timing signal based on the timing at which each of the selected power sums is obtained; sampling each of the received signals using the L symbol synchronization timing signals; Adaptively equalizing the received signal to obtain a decision symbol signal. 14. The adaptive equalization method according to claim 13, wherein the L selections select a power sum greater than a threshold to determine the L timings. 15. The adaptive equalization method according to claim 13, wherein the L selections are performed in descending order of power sum. 16. The method of claim 13, wherein the L selections include selecting a power sum greater than a largest threshold among a plurality of power sums greater than a threshold to determine a timing. A featured adaptive equalization method. 17. A process for generating a synchronization word signal having the same signal sequence as a synchronization word transmitted by a transmitter, a process for calculating a correlation between a received signal and the synchronization word signal, and using the correlation value as a correlation output signal. And calculating the power sum of the correlation output signal within a certain time width while shifting the time, and detecting the timing at which the power sum of which the magnitude of the power sum first exceeds the threshold is obtained. Generating a symbol synchronization timing signal based on the timing; sampling the reception signal using the symbol synchronization timing signal and the reception signal; and performing adaptive equalization processing on the sampled reception signal to make a determination. Determining a symbol signal; and an adaptive equalization method comprising: 18. A process for generating a synchronization word signal having the same signal sequence as a synchronization word transmitted by a transmitter, a process for calculating a correlation between a received signal and the synchronization word signal, and using the correlation value as a correlation output signal. The average value and the variance value of the correlation output signal within the fixed time width are obtained while shifting the time width in time, and K variance values at the timing when the average value is larger than the threshold signal (K is 1
The above integer), a step of generating a symbol synchronization timing signal based on the K timings, a step of sampling each of the reception signals using the K symbol synchronization timing signals, Adaptively equalizing the sampled received signal to obtain a decision symbol signal. 19. The method according to claim 13, 17 or 18, wherein the correlation power signal within the fixed time width is sampled at a sampling cycle for the reception signal, and the sum of the sampled signals is used as the power sum. Or the power variance value of the sampled signal is set to the variance value. 20. The method according to claim 13, wherein a step of generating a second symbol synchronization timing signal based on a timing of a preceding wave, and communicating the symbol synchronization timing signal and the second symbol synchronization timing signal. An adaptive equalization method comprising a step of adaptively switching the received signal as a symbol synchronization timing signal used for the sampling according to the quality. 21. The method according to claim 18, wherein a sum of powers of the correlation output signals within the predetermined time width is obtained while shifting a time width in time, and L selected from the power sums are selected. (L is an integer equal to or greater than 1) to determine respective timings at which respective power sums are obtained, and based on these L timings, a process of generating a second symbol synchronization timing signal; Adaptively switching a second symbol synchronization timing signal as a symbol synchronization timing signal used for the sampling of the received signal according to communication quality. 22. The method according to claim 18, wherein a sum of powers of the correlation output signals within the fixed time width is obtained while shifting a time width in time, and L selected from the power sums are selected. (L is an integer of 1 or more) to obtain respective power sums, a process of generating a second symbol synchronization timing signal based on these L timings, and a third process based on the timing of the preceding wave. Generating a symbol synchronization timing signal, and using the symbol synchronization timing signal, the second symbol synchronization timing signal, and the third symbol synchronization timing signal in accordance with communication quality to determine a symbol used for the sampling of the reception signal. Adaptively switching as a synchronization timing signal. 23. The method according to claim 13, wherein said L or K is plural, and said adaptive equalization processing calculates an error signal power between said plurality of sampled received signals and each replica signal. , Add these error signal powers,
An adaptive equalization method, wherein symbol determination is performed by performing adaptive equalization processing based on the added error signal power. 24. The method according to claim 13, wherein L or K is a plurality, and the adaptive equalization process performs an adaptive equalization process on each of the plurality of sampled received signals. An adaptive equalization method characterized by performing a process according to communication quality on a result of an adaptive equalization process to obtain a final result. 25. The adaptive equalization method according to claim 13, 17 or 18, wherein said adaptive equalization processing performs signal processing in a spatial domain together with equalization processing in a time domain. 26. The method according to claim 13, 17 or 18, wherein weights are respectively applied to received signals from a plurality of antennas to form multi-beam directivity characteristics, and each received signal from each beam of the multi-beams is formed. And an adaptive equalization method, wherein the correlation calculation is performed, a symbol synchronization timing signal based on the power sum or the variance value is obtained, and a corresponding beam reception signal is sampled by each of the symbol synchronization timing signals.