JP4429744B2 - Adaptive signal processing apparatus and adaptive signal processing method - Google Patents

Description

The present invention relates to an adaptive signal processing device and an adaptive signal processing method for calculating a weighting factor of a signal received by an array antenna.

  Conventionally, in wireless communication, radio waves are reflected, diffracted, and scattered by obstacles such as buildings. For this reason, since the wireless propagation path becomes a multiple propagation path, multipath fading due to multiple waves occurs, and communication quality deteriorates. Therefore, in order to reduce these adverse effects, an adaptive array antenna system is provided in a radio apparatus, for example, a radio base station or a mobile station.

  The adaptive array antenna system includes an array antenna in which a plurality of antenna elements are arranged, and receives a signal received by the array antenna by forming a directivity pattern by adaptive signal processing. As a result, a reception directivity pattern can be formed in the arrival direction of the desired wave and a null of the directivity pattern can be formed in the arrival direction of the interference wave such as a delayed wave to suppress the interference wave. Communication quality has been improved. Further, if the above-described directivity pattern is applied at the time of transmission, there are advantages that interference with wireless devices other than the transmission partner can be reduced and transmission power can be reduced.

An adaptive algorithm based on MMSE (Minimum Mean Square Error) is used for adaptive signal processing in the adaptive array antenna system described above. Known adaptive algorithms based on MMSE include, for example, LMS (Least Mean Square) and RLS (Recursive Least-Squares). In the adaptive signal processing by this MMSE-based adaptive algorithm, an average square error is obtained from the difference between the local reference signal generated inside the wireless device and the training signal in the received signal, and the value of this error is minimized. A weight (weight coefficient) for controlling the phase and amplitude of the received signal is calculated (for example, see Non-Patent Document 1).
Nobuyoshi Kikuma, “Adaptive signal processing by array antenna”, Science and Technology Publishing Co., Ltd., November 1998, p. 35-64

However, the conventional techniques described above have the following problems.
As a wireless communication system in which a training signal such as a unique word or a pilot signal is transmitted in bursts, a HRPD (High PD) adopted in a TDMA (Time Division Multiple Access) system, a CDMA system called “cdma2000 lxEV-DO”, or the like. Rate Packet Data) method is known. In these wireless communication systems, when adaptive signal processing using an adaptive algorithm such as an MMSE base is applied, the referenced training signal is received in bursts. Therefore, the adaptive signal processing is performed in bursts every time a training signal is received. Will be. Therefore, in the adaptive signal processing for calculating the weight, the processing is stopped in a section other than the training signal reception section, and the weight calculation calculation cannot be executed continuously. For this reason, it is desirable that the adaptive signal processing converges to an optimum weight within one training signal reception section.

  However, since the convergence speed of adaptive signal processing differs depending on the type of adaptive algorithm, the received radio wave environment, and the like, there is a case where it does not converge within one training signal reception section and an optimal weight cannot be obtained. For example, when comparing the LMS algorithm and the RLS algorithm, the convergence speed of the LMS algorithm is slower. Therefore, in the LMS algorithm, there is a high possibility that an optimal weight cannot be obtained within one training signal reception section, and there is a possibility that the communication quality may deteriorate. For this reason, although the LMS algorithm has the advantages that the calculation load is lighter than that of the RLS algorithm and the circuit configuration is simple, the LMS algorithm may not be adopted.

The present invention has been made in consideration of such circumstances, and its purpose is to continuously perform adaptive signal processing for calculating weights (weighting factors) when the referenced training signal is burst reception. It is an object of the present invention to provide an adaptive signal processing apparatus and an adaptive signal processing method capable of realizing an adaptive array antenna system capable of improving communication quality by being executed.

In order to solve the above problems, an adaptive signal processing device according to the present invention comprises adaptive signal processing means for calculating a weighting factor for forming a directivity pattern of an array antenna comprising a plurality of antenna elements, and the array antenna. A signal storage means for storing the training signal included in the received signal received by the step of supplying the received training signal to the adaptive signal processing means during a period in which the training signal is included in the received signal, During a period in which no training signal is included in the received signal, a partial training signal is created by sampling the training signal stored in the signal storage means at regular intervals, and the created partial training signal Training signal supply means for repeatedly supplying the adaptive signal processing means to the adaptive signal processing means To.

An adaptive signal processing device according to the present invention is included in adaptive signal processing means for calculating a weighting factor for forming a directivity pattern of an array antenna composed of a plurality of antenna elements, and a received signal received by the array antenna. A training signal is sampled at regular intervals to create a partial training signal, and a signal storage means for storing the created partial training signal, and a reception signal during a period in which the received signal is included in the training signal The training signal is supplied to the adaptive signal processing means, while the partial training signal stored in the signal storage means is repeated during the period when the training signal is not included in the received signal. And a training signal supply means for supplying to the processing means.

An adaptive signal processing method according to the present invention is included in an adaptive signal processing process for calculating a weighting factor for forming a directivity pattern of an array antenna composed of a plurality of antenna elements, and a received signal received by the array antenna. A signal storage process for storing a training signal, a first training signal supply process for supplying the received training signal to the adaptive signal processing process in a period in which the training signal is included in the received signal, and the received signal In a period in which no training signal is included in the second training, a partial training signal generated by sampling the training signal stored in the signal storage process at a predetermined interval is repeatedly supplied to the adaptive signal processing process. And a signal supply process.

An adaptive signal processing method according to the present invention is included in an adaptive signal processing process for calculating a weighting factor for forming a directivity pattern of an array antenna composed of a plurality of antenna elements, and a received signal received by the array antenna. The training signal is sampled at regular intervals to create a partial training signal, the signal storage process for storing the created partial training signal, and the reception signal is received during the period when the received signal is included in the training signal. The first training signal supply process for supplying the training signal to the adaptive signal processing process, and the partial training signal stored in the signal storage process in a period when the training signal is not included in the received signal. A second training signal supply process for repeatedly supplying to the adaptive signal processing process. It is characterized in.

  According to the present invention, adaptive signal processing for calculating a weighting factor (weight) can be continuously performed continuously when a training signal to be referred to is burst reception. As a result, there is a high possibility that the adaptive signal processing is executed until it substantially converges, so that a more appropriate weight can be obtained and the communication quality is improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an adaptive array antenna system according to a first embodiment of the present invention. The adaptive array antenna system shown in FIG. 1 is provided in, for example, a radio base station in a radio communication system, and uses an array antenna including a plurality of antenna elements 1-1 to N as a radio signal transmitted from a mobile station. The received signals x _{1 to} x _N are weighted with weights w _{1 to} w _N (weighting factors) for forming the directivity pattern of the array antenna and synthesized to generate an array output signal y. It is.

In FIG. 1, the wireless transmission / reception unit 2 performs transmission and reception using antenna elements 1-1 to N. In FIG. 1, other blocks related to the transmission function are omitted. Wireless transceiver 2, the N received signals from the antenna elements 1-1 to 1-N, converted and amplified into a baseband signal, into a digital signal, and outputs the received signal x ₁ ~x _N. These received signals x _{1 to} x _N correspond to the antenna elements 1-1 to _N , respectively.

The adaptive signal processing unit 3 performs adaptive signal processing using an adaptive algorithm such as an MMSE base, for example, an LMS algorithm, and calculates weights w _{1 to} w _N for forming an optimal directivity pattern of the array antenna. To do. The signal synthesizer 4 includes N multipliers 11 and one adder 12 provided corresponding to the antenna elements 1-1 to N, respectively. Received signals x _{1 to} x _N and weights w _{1 to} w _N are input to the signal synthesis unit 4. In the signal combining unit 4, the received signal x ₁ ~x _N, after being weighted it is multiplied by the corresponding weight w ₁ to w _N, respectively, by the multipliers 11 are synthesized is added by the adder 12. The combined signal is output as an array output signal y.

In the adaptive signal processing unit 3, the weight vector W is calculated from the training signal supplied from the training signal supply unit 6, the reference signal supplied from the reference signal generation unit 7, and the array output signal y by the expression (1). Is done. The reference signal supplied from the reference signal generation unit 7 is a predetermined signal corresponding to the training signal.
W (m) = W (m-1)-[mu] .Z (m-1) .e ^* (m-1)
= W (m-1)
−μ · Z (m−1)
· {R (m-1) -W (m-1) H · Z (m-1)} *
... (1)
However, the weight vector W = [w ₁ ,..., W _N ] ^T ,
Z is a training signal, Z = [z ₁ ,..., Z _N ] ^T ,
r is a predetermined reference signal corresponding to the training signal,
e is an error signal which is the difference between the reference signal r and the array output signal y;
m is the number of updates of adaptive signal processing,
μ is the step size to adjust the weight update rate,
^T is the transposition notation,
^H is the notation of complex conjugate transpose,
^* Is a complex conjugate notation,
It is.

The array output signal y is expressed by equation (2).
y = W ^H · X (2)
However, the received signal vector X = [x ₁ ,..., X _N ] ^T.
As represented by the above equation (2), the array output signal y is generated by weighting the received signal vector X by the weight vector W. As a result, the array output signal y becomes a received signal based on the directivity pattern of the array antenna formed by the weights w _{1 to} w _N.

The training signal storage unit 5 extracts and stores the training signals included in the received signals x _{1 to} x _N.
The training signal supply unit 6 supplies a training signal to the adaptive signal processing unit 3. The training signal supply unit 6 detects a training signal reception section using any one of the reception signals x _{1 to} x _N. In the training signal receiving section, the received training signal is supplied to the adaptive signal processing unit 3. On the other hand, in a period other than the training signal reception period, a training signal is partially read out from the training signal storage unit 5 and copied using the read partial training signal (hereinafter referred to as a partially duplicated training signal). Is supplied to the adaptive signal processing unit 3. The supply of the partially duplicated training signal is repeated until the next training signal is received.

  FIG. 2 is a conceptual diagram for explaining this training signal supply method. In the example of FIG. 2, the data signal is included between the training signals of the received signal (between the p-th training signal and the (p + 1) -th training signal). The training signal has a signal length Nt, and the data signal has a signal length Nd. As shown in FIG. 2, the partially duplicated training signal is continuously supplied to the adaptive signal processing unit 3 until the (p + 1) th training signal is received, continuously from the received pth training signal. The signal length of the partially duplicated training signal is Nk. However, Nk is less than the signal length Nt of the training signal. As a result, the maximum number of times the same partially duplicated training signal is repeatedly supplied to the adaptive signal processing unit 3 is “Nd / Nk”. The details of the method for creating the partially duplicated training signal will be described later.

  The training signal supply unit 6 instructs the reference signal generation unit 7 to generate a reference signal. This reference signal generation instruction is performed in response to the supply of the training signal to the adaptive signal processing unit 3. That is, it instructs to generate a predetermined reference signal (signal length Nt) corresponding to the received training signal (signal length Nt) in the training signal reception section.

  On the other hand, in a period other than the training signal reception period, a reference signal generation condition is instructed so as to generate a partial reference signal (signal length Nk) corresponding to the partially duplicated training signal (signal length Nk). This reference signal generation condition indicates which of the predetermined reference signals (signal length Nt) corresponds to the partially duplicated training signal.

  The reference signal generation unit 7 generates a corresponding reference signal based on a known reference signal in accordance with a reference signal generation instruction from the training signal supply unit 6 (see FIG. 2). Then, the generated reference signal is supplied to the adaptive signal processing unit 3.

  Thus, the adaptive signal processing unit 3 is continuously supplied with the training signal supplied from the training signal supply unit 6 and the reference signal corresponding to the training signal. As a result, in the example of FIG. 2, the data signal is included between the p-th training signal and the (p + 1) -th training signal, and the training signal is burst-received. ) Since the training signal and the reference signal corresponding to the training signal are continuously supplied to the adaptation signal processing unit 3 in the section T (p) _all until the reception of the training signal for the second time, the adaptation for weight calculation is performed. Signal processing is performed continuously.

  As described above, according to the present embodiment, the adaptive signal processing unit 3 is always supplied with a training signal and a reference signal corresponding to the training signal. Thereby, when the training signal to be referred to is burst reception, the adaptive signal processing for calculating the weight can always be executed continuously. As a result, there is a high possibility that the adaptive signal processing is executed until it substantially converges, so that a more appropriate weight can be obtained and the communication quality is improved.

  Also, the convergence speed is slower than that of the RLS algorithm, but it is easy to adopt the LMS algorithm with a light computation load and a simple circuit configuration. By using the LMS algorithm, the device configuration can be simplified and the power can be saved. Can do.

Next, a method for creating the above-described partially duplicated training signal will be described.
As described above, the partially duplicated training signal (signal length Nk) is composed of a part of the training signal (signal length Nt) (where Nk is less than Nt). 3 and 4 are diagrams for explaining an example of creating a partially duplicated training signal.

  In the example of FIG. 3, a signal of a continuous partial section (a continuous section corresponding to the signal length Nk) is extracted from the training signal (signal length Nt) to be a partially duplicated training signal. Here, it is desirable to select the section to be extracted by excluding the head portion of the training signal (signal length Nt). This is because the head portion of the training signal may be affected by a delayed wave of a signal before the training signal (for example, the data signal in FIG. 2), which may adversely affect adaptive signal processing. Because. Thereby, for example, as shown in FIG. 3, the central portion of the training signal is extracted to create a partially duplicated training signal.

  In the example of FIG. 4, a partially duplicated training signal is created by sampling a signal length Nk from a training signal (signal length Nt) at a constant interval. For example, an odd number signal of the training signal is extracted. Alternatively, even-numbered signals are extracted. As described above, it is desirable not to include the sampling signal at the head of the training signal in the partially duplicated training signal. For example, the central part of the training signal is sampled by combining both the methods shown in FIGS.

  As described above, in a period other than the training signal reception period, a part of the training signal is repeatedly supplied to the adaptive signal processing unit 3 as a partially duplicated training signal, so that the entire part of the training signal is repeatedly supplied. The number of signal processing can be increased. Thereby, the accuracy of the weight is improved and the communication quality is improved.

  FIG. 5 is a graph for illustrating the communication quality improvement effect according to the present invention. FIG. 5 shows a simulation result (C / I cumulative probability distribution) of C / I (Carrier to Interference power Ratio) using an adaptive array antenna. Waveforms A1, A2, and A3 are simulation results according to the present invention, and waveform B is a conventional simulation result. The simulation conditions are as follows: the array antenna is a four-element array arranged in a square at half-wave intervals, the fading frequency is 31.9 Hz, the desired wave is 1 wave (0 dB), and the interference wave is 3 waves (-5 dB, 10 dB, -5 dB: C /I=-10.3 dB), the adaptation algorithm is LMS.

In the conventional waveform B, adaptive signal processing is performed only in the training signal reception section. In addition, the weight calculated by the previous adaptive signal processing is used as the initial value of the weight.
In the waveform A1, a continuous section including the center portion of the training signal (signal length Nt / 2 minutes) is a partially duplicated training signal (signal length Nk) (ie, Nk = Nt / 2).
In the waveform A2, a continuous section including the center portion of the training signal (signal length Nt / 4 minutes) is a partially duplicated training signal (signal length Nk) (that is, Nk = Nt / 4).
In the waveform A3, odd-numbered training signals are sampled to obtain a partially duplicated training signal (signal length Nk) (that is, Nk = Nt / 2).
Each of the waveforms A1 to A3 uses the weight calculated by the immediately preceding adaptive signal processing using the received training signal or the partially duplicated training signal as the initial value of the weight.

  As shown in FIG. 5, according to the present invention, the communication quality is improved compared to the prior art regardless of which partial duplication training signal is used. Further, the improvement effect may be greater as the signal length of the partially duplicated training signal is shorter.

  Further, when a sampling signal is used, an even greater improvement effect can be obtained. The reason for this is that although the resolution deteriorates by sampling at regular intervals, the C / I improves due to factors such as the fact that the sampling signal contains time-varying components of the radio propagation environment in the entire training signal reception section. Because it does.

  In the above-described embodiment, the training signal supply unit 6 partially reads out the training signal stored in the training signal storage unit 5 and creates a partially duplicated training signal, but the training signal storage unit 5 A signal may be partially extracted from the training signal included in the received signal and stored. In this way, the memory amount of the training signal storage unit 5 can be reduced, so that it is possible to reduce power consumption and cost, downsize the apparatus, and the like.

  Next, a second embodiment will be described. FIG. 6 is a block diagram showing a configuration of an adaptive array antenna system according to the second embodiment of the present invention. In FIG. 6, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. The adaptive array antenna system shown in FIG. 6 further includes a weight storage unit 31, a weight selection unit 32, and a signal synthesis unit 40 in the configuration of FIG. In FIG. 6, the signal synthesis unit 4 generates a feedback signal ya used in the adaptive signal processing and outputs it to the adaptive signal processing unit 3.

In FIG. 6, the weight storage unit 31 selects and stores weights wm ₁ to wm _N for generating the array output signal y from the weights w _{1 to} w _N calculated by the adaptive signal processing unit 3. The weight selection unit 32 receives the weights wm _{1 to} wm _N stored in the weight storage unit 31 and the weights w _{1 to} w _N calculated by the adaptive signal processing unit 3. The weight selection unit 32 selects an optimum weight among the weights wm _{1 to} wm _N stored in the weight storage unit 31 or the latest weights w _{1 to} w _N calculated by the adaptive signal processing unit 3. . The selected weights ws _{1 to} ws _N are input to the signal synthesizer 40 and set in the corresponding multipliers 11. Then, the signal synthesis unit 40 weights the received signals x _{1 to} x _N with the weights ws _{1 to} ws _N and synthesizes them to generate the array output signal y.

In the configuration of FIG. 6 described above, the weights ws _{1 to} ws _N for generating the array output signal y are selected from the weights w _{1 to} w _N calculated by the adaptive signal processing unit 3. Various methods can be considered as the weight selection method, and an example thereof will be described below.

First weight selection method;
FIG. 7 is a conceptual diagram for explaining the first weight selection method. Weight storage unit 31, in FIG. 7, it stores the weights w ₁ to w _N to adaptive signal processing by the training signal of the received signal is finally calculated in a section that runs as the weight wm ₁ ~wm _N. Then, the weight selection unit 32 selects the weights wm _{1 to} wm _N stored in the weight storage unit 31 for weighting the data signal received subsequent to the training signal of the reception signal. For example, the weights w _{1 to} w _N finally calculated in the section T (p) _1 are stored, and the stored weights w _{1 to} w _N are applied to the data signal following the p-th training signal.

Second weight selection method;
FIG. 8 is a conceptual diagram for explaining the second weight selection method. In FIG. 8, the weight selection unit 32 uses the weights w _{1 to} w _N finally calculated in the adaptive signal processing for each training signal supply section supplied to the adaptive signal processing unit 3 as the next training signal. Is selected for weighting the data signal received in the section corresponding to the supply section.

For example, the weights w _{1 to} w _N finally calculated in the section T (p) _1 are applied to the data signal of the reception signal corresponding to the section T (p) _2 following the p-th training signal. Next, the weights w _{1 to} w _N finally calculated in the section T (p) _2 are applied to the data signal of the reception signal corresponding to the section T (p) _3. In this way, the weights w _{1 to} w _N calculated in the immediately preceding training signal supply interval are applied to the data signal of the reception signal corresponding to the next supply interval. The weights w _{1 to} w _N calculated in the immediately preceding section T (p) _n−1 are applied to the data signal of the received signal corresponding to the last training signal supply section T (p) _n. .

Third weight selection method;
FIG. 9 is a conceptual diagram for explaining the third weight selection method. Weight storage unit 31, in FIG. 9, for each signal length Nt interval of the training signal, to store the weights w ₁ to w _N, which is calculated by the adaptive signal processing section 3 as the weight wm ₁ ~wm _N. Then, the weight selection unit 32 selects the weights wm _{1 to} wm _N stored in the weight storage unit 31 for the weighting of the data signal received subsequent to the signal length Nt interval. For example, the weights w _{1 to} w _N calculated in the section T (p) _1a are applied to the data signal of the reception signal corresponding to the section T (p) _1b of the next signal length Nt. Next, the weights w _{1 to} w _N calculated in the section T (p) _1b are applied to the data signal of the reception signal corresponding to the section T (p) _1c of the next signal length Nt. In this manner, the weights w _{1 to} w _N calculated in the immediately preceding signal length Nt are applied to the data signal of the received signal corresponding to the next signal length Nt. Then, the weight w ₁ calculated in the section T (p) _1 (j−1) of the immediately preceding signal length Nt with respect to the data signal of the received signal corresponding to the section T (p) _1j of the last signal length Nt. ~w _N is applied.

Note that the weight selected by any of the first to third weight selection methods described above can be used as the weight initial value of the adaptive signal processing. For example, the weights w _{1 to} w _N finally calculated in the adaptive signal processing section based on the immediately preceding training signal may be used by the second weight selection method. Thus, in FIG. 8, in the adaptive signal processing interval T (p + 1) _all based on the (p + 1) -th training signal, the adaptive signal processing interval based on the p-th training signal is used as the initial value of the adaptive signal processing weight. T (p) in _all final weights w ₁ to w _N, that is, the weight w ₁ to w _N, which is calculated in the interval T (p) _n used. Thereby, since the adaptive signal processing is started from the weight initial value that matches the current wireless propagation environment, the convergence time can be shortened.

  Further, the weight used for weighting the data signal and the weight initial value of the adaptive signal processing may be selected by the same selection method or may be selected by different selection methods.

Further, a square error e representing the accuracy of the weights w _{1 to} w _N may be calculated from the equation (3), and an optimum weight may be selected based on the square error e. This square error may be an instantaneous value or an average value for a certain period.
e = | r−W ^H · Z | ² (3)

Further, when the square error e of the latest weights w _{1 to} w _N is equal to or less than a predetermined threshold value that maintains a certain accuracy, the adaptive signal is applied only during the period until the next training signal is received. The operation of the processing unit 3 may be temporarily stopped. As a result, power consumption can be reduced.

  Further, reception quality characteristic measuring means for measuring the reception quality characteristic based on the array output signal y may be provided, and an optimum weight may be selected based on the reception quality characteristic. As reception quality characteristics, for example, C / I, SINR (Signal to Interference and Noise power Ratio), BER (Bit Error Rate), FER (Frame Error Rate), and the like can be used.

  Further, the first to third weight selection methods described above may be combined with the selection method based on the square error e or the reception quality characteristic.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention.
For example, the optimum weight used for the reception process may be used for forming the directivity pattern for transmission.

According to the present embodiment, various effects shown below can be obtained.
According to the present embodiment, the circuit configuration is simple, can be applied to various MMSE-based adaptive algorithms, can be expected to improve communication quality, and is already provided in an actual device. Can be diverted.

As an initial value of the adaptive signal processing weight, an optimal weight, for example, weights w _{1 to} w _N finally calculated in the adaptive signal processing section based on the immediately preceding training signal, or the weight selection unit 32 performs the weighting. since ws ₁ to wS weights is selected as _N w ₁ to w _N can be used, so even LMS algorithm requires a lot of number of updates to converge to the optimum values the convergence rate is accelerated, RLS algorithm, etc. The reception quality characteristic can be improved while utilizing the advantage of the LMS algorithm that the circuit configuration is simple and the calculation load is small compared to other MMSE-based adaptive algorithms.

  In addition, an adaptive algorithm whose convergence is slowed by fluctuations in received power, such as the LMS algorithm, has a slower convergence speed in a radio propagation environment where the received power fluctuates, such as mobile communications, Since the adaptive signal processing is continued, there is a high possibility that the signal will converge to the optimum weight, and the reception quality characteristic is improved early.

  Further, since the weight calculated in the process of the applied signal processing by the partially duplicated training signal can be applied to the data signal as needed, the effect that the reception quality characteristic is further improved can be obtained.

  Further, the adaptive signal processing can be continuously executed even when the calculation speed of the adaptive signal processing is low due to the circuit configuration, so that the possibility of convergence to the optimum weight increases.

  Further, by repeatedly supplying a part of the training signal as a partially duplicated training signal to the adaptive signal processing unit, the number of times of adaptive signal processing can be increased as compared with the case where all parts of the training signal are repeatedly supplied. Thereby, the accuracy of the weight is improved and the communication quality is improved.

  Further, by creating a partially duplicated training signal by excluding the head part of the training signal, the influence of the delayed wave can be reduced, so that higher quality weight can be obtained.

  In addition, by sampling the training signal at regular intervals and creating a partially replicated training signal, it becomes possible to cover the time-varying components of the radio propagation environment in the entire area of the training signal reception section. Receive quality characteristics are improved.

  Note that the adaptive array antenna system according to the present invention can be applied to a radio apparatus such as a radio base station or a mobile station. As a result, the wireless device can receive or transmit a wireless signal with an appropriate directivity pattern, thereby improving communication quality. Examples of the mobile station include a portable wireless terminal such as a mobile phone and a wireless terminal mounted on a moving object such as a car phone.

  The present invention also provides various wireless communication systems in which training signals are transmitted in bursts, such as a TDMA (Time Division Multiple Access) system, a CDMA system called “cdma2000 lxEV-DO”, etc. (High Rate Packet Data) method.

It is a block diagram which shows the structure of the adaptive array antenna system by the 1st Embodiment of this invention. It is a conceptual diagram for demonstrating the supply method of the training signal which concerns on embodiment of this invention. It is a figure for demonstrating the 1st example of preparation of a partial replication training signal. It is a figure for demonstrating the 2nd example of preparation of a partial replication training signal. It is a graph for showing the communication quality improvement effect by the present invention. It is a block diagram which shows the structure of the adaptive array antenna system by the 2nd Embodiment of this invention. It is a conceptual diagram for demonstrating the 1st weight selection method which concerns on embodiment of this invention. It is a conceptual diagram for demonstrating the 2nd weight selection method which concerns on embodiment of this invention. It is a conceptual diagram for demonstrating the 3rd weight selection method which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1-1-N ... Antenna element, 2 ... Wireless transmission / reception part, 3 ... Adaptive signal processing part, 4,40 ... Signal synthetic | combination part, 5 ... Training signal storage part, 6 ... Training signal supply part, 7 ... Reference signal generation part , 31 ... weight storage unit, 32 ... weight selection unit.

Claims (4)

Adaptive signal processing means for calculating a weighting factor for forming a directivity pattern of an array antenna composed of a plurality of antenna elements;
Signal storage means for storing a training signal included in the received signal received by the array antenna;
In a period in which the received signal includes a training signal, the received training signal is supplied to the adaptive signal processing unit, while in a period in which the received signal does not include a training signal, the signal storage unit Training signal supply means for sampling the training signal stored in a predetermined interval to create a partial training signal, and repeatedly supplying the created partial training signal to the adaptive signal processing means;
An adaptive signal processing device comprising: Adaptive signal processing means for calculating a weighting factor for forming a directivity pattern of an array antenna composed of a plurality of antenna elements;
A signal storage means for sampling the training signal included in the reception signal received by the array antenna at a regular interval to create a partial training signal, and storing the created partial training signal;
In a period in which the received signal includes a training signal, the received training signal is supplied to the adaptive signal processing unit, while in a period in which the received signal does not include a training signal, the signal storage unit Training signal supply means for repeatedly supplying the partial training signal stored in to the adaptive signal processing means;
An adaptive signal processing device comprising: An adaptive signal processing process for calculating a weighting factor for forming a directivity pattern of an array antenna including a plurality of antenna elements;
A signal storage process for storing a training signal included in a received signal received by the array antenna;
A first training signal supplying process for supplying the received training signal to the adaptive signal processing process during a period in which the received signal is included in the received signal;
During a period in which no training signal is included in the received signal, a partial training signal created by sampling the training signal stored in the signal storage process at regular intervals is repeatedly supplied to the adaptive signal processing process. 2 training signal supply process,
An adaptive signal processing method comprising: An adaptive signal processing process for calculating a weighting factor for forming a directivity pattern of an array antenna including a plurality of antenna elements;
A signal storage process for creating a partial training signal by sampling a training signal included in a reception signal received by the array antenna at regular intervals, and storing the created partial training signal;
A first training signal supplying process for supplying the received training signal to the adaptive signal processing process during a period in which the received signal is included in the received signal;
A second training signal supply process for repeatedly supplying the partial training signal stored in the signal storage process to the adaptive signal processing process in a period in which the received signal does not include a training signal;
An adaptive signal processing method comprising:

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