JP2001144825A - Radio reception system and detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio reception system which can highly precisely demodulate a reception signal correspondingly to a synchronous detection system without the need of complicated hardware configuration, and to provide a detection method. SOLUTION: An adaptive array processing is executed on a signal received by using a plurality of antennas ANT1 to ANT4 by DSP 10. A signal from desired PS is extracted. A compulsory phase synchronous processing with respect to a prescribed signal reference point is executed on the extracted signal by DSP 10. Phase change quantity between the two continuous symbols of the signal which is compulsorily phase-synchronized is detected and demodulation data corresponding to phase change quantity is outputted, based on a prescribed correspondency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a radio reception system and a detection method, and more particularly to a radio reception system and a detection method for demodulating a signal received from a mobile terminal device in a base station of a mobile communication system.

[0002]

2. Description of the Related Art In recent years, portable telephones (for example, Personal Handyphone System: hereinafter, P
HS), at the time of communication between a base station (Cell Station: hereinafter, CS) and a mobile terminal device (Personal Station: hereinafter, PS), a modulated wave modulated and transmitted on the transmission side is
Various schemes have been adopted as demodulation schemes for demodulation on the receiving side.

[0003] These demodulation methods are appropriately adopted according to various factors such as a modulation method on the transmission side, a communication application, and cost.

[0004] A typical demodulation method will be described below. In general, demodulation methods are roughly classified into a method using a reference signal and a method not using a reference signal.

[0005] As the latter method, there are an envelope detection method for identifying the amplitude of a signal, a frequency detection method for identifying the frequency, and the like. It is not used in current mobile communication systems. Therefore, the description of the latter method is omitted, and the former method will be described in more detail below.

Representative examples of the former method include a synchronous detection method in which a carrier is reproduced from a received signal and used as a reference signal, and a delay detection method in which a signal delayed by one symbol from the received signal is used as a reference signal. Is adopted in the current PHS.

FIG. 7 is a schematic block diagram for explaining the principle of the synchronous detection system. Referring to FIG. 7, reception signal A (t) cosωt extracted through reception filter 1
Is supplied to one input of the multiplier 2 and to the carrier recovery circuit 3. The carrier recovery circuit 3 recovers the carrier cosωt from the received signal A (t) cosωt,
The other input of the multiplier 2 is given.

Multiplier 2 receives these inputs and performs the following operation: A (t) cosωt × cosωt = (A (t) + A
(T) cos2ωt) / 2 The result of this multiplication is given to the low-pass filter (LPF) 4, and A (t) / 2 is output as a demodulated output.

In this synchronous detection system, the carrier recovery circuit 3
Is detecting the same phase and the same frequency as the carrier.
It can be said that this is the most accurate demodulation method. This synchronous detection method is adopted, for example, in CS of PHS.

FIG. 8 is a schematic block diagram for explaining the principle of the differential detection system. Referring to FIG. 8, the received signal extracted via reception filter 1 is applied to one input of multiplier 2 and applied to delay circuit 5 to be delayed by one symbol. One symbol delay circuit 5
The received signal delayed by one symbol is applied to the other input of multiplier 2.

The multiplier 2 multiplies the two preceding and succeeding symbols, and the output is output via the LPF 4. That is, the symbol phase difference before and after the low frequency component of the product of the received signal and the one-symbol delayed signal is transmitted as one data. For example, if there is no change in the phase difference information of the preceding and following symbols, data "0" is demodulated and transmitted if there is a change in the phase difference information. This differential detection method is employed, for example, in a PHS PS.

[0012]

The synchronous detection system shown in FIG. 7 enables demodulation with very high precision as described above, but on the other hand, the hardware configuration becomes large and complicated. There is a problem of doing.

More specifically, in order to realize the carrier recovery circuit 3 shown in FIG. 7, a combination of a received signal multiplication circuit and a PLL circuit is required, or a method such as a Costas loop or an inverse modulation method is used. Requires a circuit configuration for realizing. For this reason, in the synchronous detection method, the circuit scale and cost are increased.

On the other hand, in the differential detection system shown in FIG. 8, since a delayed received signal is used as it is as a reference signal, a complicated hardware configuration such as the synchronous detection system described above is not required. Further, since the multiplier 2 multiplies one symbol of the delayed signal by one symbol of the received signal, the noise included in each signal is also multiplied, and the noise is reduced to some extent as a whole.

However, the influence of noise remains to some extent, and the delay detection method is not as good as the synchronous detection method in demodulation accuracy.

SUMMARY OF THE INVENTION An object of the present invention is to provide a radio receiving system and a detecting method capable of demodulating a received signal with high accuracy according to a synchronous detection method without requiring a complicated hardware configuration. It is.

[0017]

According to the first aspect of the present invention, a radio receiving system for receiving a signal from a mobile terminal device using a plurality of antennas performs an adaptive array process on the received signal. Signal extraction means for extracting a signal from a desired mobile terminal device, and forced phase synchronization for forcibly synchronizing the phase of each symbol point of the extracted signal with the phase of the closest signal reference point among predetermined signal reference points Means, phase change detecting means for detecting a phase change between two symbols of the phase-synchronized signal, and demodulation of data corresponding to the detected phase change based on a predetermined correspondence between the phase difference and the data. Demodulated data output means for outputting as data.

According to the invention of claim 2, according to claim 1,
Wherein the signal from the mobile terminal device has a predetermined reference signal for each predetermined section, the signal extracting means calculates a weight vector of the received signal, and the calculated weight Means for performing a product-sum operation between the vector and the received signal, outputting the result as a signal from a desired mobile terminal device, and means for storing a predetermined reference signal, and calculating a weight vector, The weight vector is updated so as to reduce the square of the error between the result of the product-sum operation and the stored reference signal.

According to the invention of claim 3, according to claim 2,
Means for calculating a weight vector, in a section of the received signal where a reference signal is present (known), based on a stored reference signal, using a RLS algorithm or an LMS algorithm. The vector is updated, and in the section of the received signal where there is no reference signal (unknown), the weight vector is updated using the LMS algorithm or the RLS algorithm based on the reference signal calculated backward from the previously calculated weight vector. Perform

According to the invention described in claim 4, according to claim 1,
4. In the wireless receiving system according to any one of to
The predetermined signal reference point is 1 which alternates every symbol.
Π / 4 shift QP composed of 2 sets of 4 points
These are the eight reference points of SK.

According to the invention described in claim 5, according to claim 1,
5. In the wireless receiving system according to any one of to
The predetermined correspondence between the phase difference and the data is (-3π / 4,
11), (3π / 4,01), (π / 4,00), (−
π / 4, 10).

According to the sixth aspect of the present invention, a detection method in a radio receiving system for receiving a signal from a mobile terminal device using a plurality of antennas performs an adaptive array process on the received signal to perform a desired movement. Extracting the signal from the terminal device, forcibly synchronizing the phase of each symbol point of the extracted signal with the phase of the closest signal reference point among predetermined signal reference points, Detecting a phase change between two symbols of the signal; and outputting data corresponding to the detected phase change as demodulated data based on a predetermined correspondence between the phase difference and the data.

According to the invention of claim 7, according to claim 6,
In the detection method according to the above, the signal from the mobile terminal device has a predetermined reference signal for each predetermined section, the step of extracting the signal, the step of calculating the weight vector of the received signal, the calculated Performing a product-sum operation of the weight vector and the received signal, outputting the result as a signal from a desired mobile terminal device, and storing a predetermined reference signal, and calculating the weight vector , The weight vector is updated so as to reduce the square of the error between the result of the product-sum operation and the stored reference signal.

According to the invention described in claim 8, according to claim 7,
In the detection method described in the above, the step of calculating the weight vector, in the section of the received signal with a reference signal (known), based on the stored reference signal,
The weight vector is updated using the RLS algorithm or the LMS algorithm, and in a section of the received signal where there is no reference signal (unknown), L is calculated based on the reference signal calculated backward from the previously calculated weight vector.
The weight vector is updated using the MS algorithm or the RLS algorithm.

According to the ninth aspect of the present invention, the sixth aspect is provided.
In the detection method according to any one of (1) to (8), the predetermined signal reference point is one set 4
Π / 4 shift QPSK 8 consisting of two sets of points
The reference point for the point.

According to a tenth aspect of the present invention, in the detection method according to any one of the sixth to ninth aspects, the predetermined correspondence between the phase difference and the data is (-3π / 4, 1
1), (3π / 4,01), (π / 4,00), (−π
/ 4, 10).

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a CS receiver extracts a received signal from a desired PS by adaptive array processing, and forcibly synchronizes the extracted signal with a predetermined signal reference point. The phase change information between symbols is detected and differential decoding is performed to obtain demodulated data.

FIG. 1 is a block diagram schematically showing a hardware configuration of a CS receiver according to the present invention.

Referring to FIG. 1, a plurality of, for example, four
Antenna ANT₁, ANT_Two, ANT _Three, ANT_FourReceived by
The signal from the received PS is transmitted to the corresponding RF circuit RF.₁, R
F_Two, RF_Three, RF_FourA / D conversion after amplification in
Exchanger AD₁, AD_Two, AD_Three, AD_FourConvert to digital signal with
Is done.

A / D converters AD ₁ , AD ₂ , AD ₃ , AD ₄
The output of the digital signal processor (hereinafter, DS
P) 10, the operation of the embodiment of the present invention is:
The DSP 10 implements the software.

In the DSP 10 shown in FIG. 1, the main processing executed by software by the DSP is "adaptive array processing", "forced phase synchronization processing", "differential decoding",
And "Reproduction of demodulated data" are listed over time. These processes will be described in detail below.

The data from the desired PS is finally demodulated from the DSP 10 of FIG. 1 and output to the outside.

FIG. 2 shows a DS according to an embodiment of the present invention.
It is a figure for explaining the flow of the whole processing of P10, and the principle.

In FIG. 2, four reception signal lines from the four A / D converters in FIG. 1 are represented by one signal line for convenience of description, and are referred to as "reception signals". .

The received signal is supplied to the DSP 1 via a receiving filter 11 not shown in the hardware configuration diagram of FIG.
Input to 0.

In general, a signal used for communication in PHS or the like is always π / 4 shifted QPSK (Quadri) at each symbol point.
There is a true signal point at any of the signal reference points of phase phase shift keying (8 points indicated by 〇 in each (I, Q) coordinate in FIG. 2). However, the I and Q phases of the signal wave actually received by the CS are indicated by (I,
Q) As depicted in the coordinate constellation, π
It does not converge to the signal reference point of / 4 shift QPSK.

For the received signal in such a state, the DSP
10, an adaptive array process is performed first.

In the adaptive array processing, a weight vector composed of a reception coefficient (weight) for each antenna is calculated based on a received signal and adaptively controlled.
This is a process for accurately extracting a signal from a desired PS.

FIG. 3 is a functional block diagram for functionally explaining the adaptive array processing by the DSP 10. As shown in FIG.

Referring to FIG. 3, weight calculation circuit 20
Calculates a weight vector W (t) composed of weights for each antenna by an algorithm described later, and receives a complex signal with a received signal X (t) from the corresponding antenna by multipliers MP ₁ , MP ₂ , MP ₃ , and MP ₄ . Multiply. The sum Y (t) of the multiplication results is obtained by the adder 21, and this Y (t) is expressed as a complex multiplication sum as follows: Y (t) = W (t) ^H X (t) where , W (t) ^H represent the transpose of the complex conjugate of the weight vector W (t).

The result Y (t) of the complex multiplication sum as described above
Is supplied to one input of a subtractor 22, and an error from a known reference signal d (t) stored in a memory of the CS in advance is obtained. This reference signal d (t) is a known signal common to all users included in the received signal from the PS,
For example, in PHS, a preamble section composed of a known bit string is used in a received signal.

The weight calculation circuit 20 executes a process of updating the weight coefficient so as to reduce the square of the error calculated by the subtractor 22. In the adaptive array processing, such updating of the weight vector (weight learning) is adaptively performed according to a change in time or a propagation path characteristic of a signal radio wave, and an interference wave component or noise is extracted from the received signal X (t). Then, the signal Y (t) from the desired PS is extracted.

In the weight calculation circuit 20 according to the embodiment of the present invention, as described above, the steepest descent method based on the square of the error (Minimum Mean Square Error: MMS)
The weight vector is updated, that is, weight learning is performed by E). More specifically, the weight calculation circuit 20 uses the MMSE RLS (Recurs
ive Least Squares) algorithm and LMS (Least Mea
n Squares) algorithm.

The adaptive array processing technology based on the MMSE and the RLS algorithm and the LMS algorithm based on the MMSE are known technologies. For example, “Adaptive signal processing using an array antenna” by Nobuyoshi Kikuma
(Science & Technology Publishing), pages 35 to 49, “Chapter 3 M
MSE Adaptive Array ".

FIG. 4 is a flowchart showing processing when the DSP 10 executes the operation of the functional block diagram of the adaptive array shown in FIG. 3 by software.

As described above, in the adaptive array processing, the complex multiplication sum Y (t) and the predetermined reference signal d
(T) An error from (t) (a known signal value such as a preamble unique word) is obtained. However, since the reference signal value does not exist in all the sections of the received signal, the received signal is set in the section where the reference signal is known. Different processing is performed depending on whether or not there is.

Referring to FIG. 4, when the adaptive array processing is started, time t is set to the first symbol in step S1. For example, one frame of the received signal of the PHS is composed of 1 to 120 symbols, of which a signal known section exists in the first half.

Next, in step S2, an initialization of the correlation matrix P, the forgetting coefficient λ, the weight vector W, and the step size μ is performed.

Next, in step S3, the symbol t
It is determined whether or not = 1 is within the section where the reference signal is known, and since it is within the section where the reference signal is known, the RLS algorithm is executed in steps S4 to S8 (for details of the RLS algorithm, refer to the above document).

First, in step S4, a Kalman gain vector K (t) at time t is calculated. The Kalman gain vector is K (t) = T (t) / (1 + X
^H (t) T (t)), where T (t) = λP
(T-1) X (t).

Next, in step S5, a known reference signal d (t) is read from the memory in the CS.

Next, in step S6, the error e (t) between the reference signal and the complex multiplication sum at time t is calculated as follows: e (t) = d (t) -W ^H (t -1) X (t) In step S7, the weight vector W (t) at time t is calculated using the Kalman gain vector K (t) as follows: W (t) = W ( t-1) + e ^* (t) K (t) (* represents a complex conjugate) Further, in step S8, the correlation matrix P (t) at time t is updated as follows: P (T) = λP (t) −K (t) ^H T (t) At this point, the RLS algorithm ends. In step S9, if the symbol t has not reached the last symbol of the frame, the symbol t is incremented. And returns to step S3. As long as it is determined in step S3 that the symbol t is within the section where the reference signal is known, the RLS algorithm of steps S4 to S8 is repeatedly executed, and in step S7, the weight vector W (t ) Is calculated.

On the other hand, in step S3, the symbol t
Is determined to be a section in which the reference signal is unknown, the LMS algorithm is executed in steps S10 to S12 (for details of the LMS algorithm, refer to the above document).

In the above-described steps S4 to S8, the weight learning is performed using the received signal X (t) and the reference signal d (t) because the received signal is in the section where the reference signal exists. Steps S10 to be described below
In the processing of S12, since the reference signal does not exist in the received signal, the complex multiplication sum of the weight vector calculated one symbol before and the received signal, and the π / 4 shift QP
Weight learning is performed using the phase difference between the SK signal reference point and the SK signal reference point as an error.

First, in step S10, the reference signal d is calculated from the weight vector W (t-1) one symbol before.
Inversely calculate (t). That is, d (t) = Det [W
(T-1) ^H X (t)], and the 4 / π shift QPSK with the shortest Euclidean distance from the I and Q signals at the signal point.
Is selected, and the signal d (t) is added to the signal reference point.
Take.

Next, in step S11, an error e (t) between the reference signal and the complex multiplication sum at time t is calculated as in step S6 described above: e (t) = d (t)- W ^H (t−1) X (t) Then, in step S12, the time t
Is calculated as follows: W (t) = W (t−1) + μe ^* (t) X (t) With the above, the LMS algorithm ends, and in step S9, the symbol t If the last symbol has not been reached, the symbol t is incremented and the process returns to step S3. Then, as long as it is determined in step S3 that the symbol t is outside the section where the reference signal is known,
The LMS algorithm in steps S10 to S12 is repeatedly executed, and the weight vector W (t) at that time is calculated in step S12 for each symbol t.

If it is determined in step S9 that the symbol t has reached t = 120, which is the last symbol of the frame, the adaptive array processing ends.

Here, if the received signal before the adaptive array processing is X (t), the processed received signal X '(t)
Is expressed as X ′ (t) = W (t) ^H X (t).

As can be understood from the flowchart of FIG. 4, the RLS algorithm of steps S4 to S8 takes a long time for weight learning because of its complicated processing, but has the advantage of fast convergence (for example, about 10 symbols). At which the weights converge). In contrast, steps S10 to S1
The LMS algorithm 2 does not require much time for weight learning because the processing is simplified, but has a disadvantage that convergence is slow (a large number of symbols are required for weight learning).

Thus, the RLS algorithm and the LMS
Algorithms have advantages and disadvantages, and adaptive array processing may be realized by appropriately combining the two in accordance with the performance of a receiver to be realized. That is, FIG.
Is a mere example, and when there is a reference signal, R
The LMS algorithm may be used instead of the LS algorithm, and the RLS algorithm may be used instead of the LMS algorithm when the reference signal is unknown.

As described above, in the signal generated by the adaptive array processing for performing the weight learning based on the known reference signal, the influence of the frequency offset and the like is considerably eliminated. This is because there is no such offset or noise in the reference signal stored in the memory in advance, and the accuracy of the signal itself generated by weight learning based on this reference signal is also improved.

Returning to FIG. 2, the (I, Q) coordinates indicated by the symbol indicate that the signal point (●) of the extracted desired signal after the adaptive array processing is concentrated near the true signal reference point (○). I do.

As described above, the true signal point of the PHS is always at one of the eight signal reference points (（) of the 4 / π-shifted QPSK, but the residual interference that could not be suppressed by the adaptive array processing was obtained. Due to factors such as wave components, noise, and problems in the accuracy of weight learning, there are some data in which the signal points (●) of the extracted symbols do not completely match the eight signal reference points (○).

For this reason, the DSP 10 executes forced phase synchronization processing after the adaptive array processing.
This process forcibly synchronizes the I and Q phases (●) of the signal points extracted by the adaptive array with the I and Q phases of the closest reference point among the signal reference points (○) of π / 4 shift QPSK. It is to let. That is, the I and Q phases of the extracted signal points are shifted by 4 / π shift QP so that the (I, Q) coordinates shown in FIG. 2 become the (I, Q) coordinates shown in FIG.
A process is performed to make the SK signal reference point coincide with the phase.

FIG. 5 shows such a forced phase synchronization process as D
FIG. 7 is a flowchart showing a process when the SP 10 executes by software.

Referring to FIG. 5, when the forced phase synchronization processing is started, time t is set to the first symbol in step S21.

Then, in step S22, the I and Q signals of the signal after the adaptive array processing are respectively (X
(T), Y (t)).

Next, in step S23, it is determined whether the symbol t is even or odd. Although it has been mentioned earlier that the true signal point of the PHS is located at any of the eight signal reference points of the 4 / π shift QPSK, more precisely, these eight signal reference points are: One set that alternates for each symbol is composed of two sets of four reference points.

More specifically, when the symbol t is an even number, as shown in step S24, the π / 4 shift QPS
The signal points of K are (1, 0), (0, 1), (-1,
0) and (0, -1).

On the other hand, when the symbol t is an odd number, as shown in step S25, the signal points of the π / 4 shift QPSK are (1, 1) / 2 ^1/2 , (-1, 1) / 2 ^{1 / 2} , (-
Four points of (1, -1) / 2 ^1/2 and (1, -1) / 2 ^1/2 are set.

In step S26, when the symbol t is even or odd, the I and Q signal coordinates (X (t), Y (t)) of the signal after the adaptive array processing are performed.
The signal reference point having the shortest Euclidean distance with respect to is selected from among the four signal reference points in any set corresponding to the time t, and (X (t), Y (t)) is set to the signal reference point. Are forcibly synchronized with the I and Q signals.

If it is determined in step S27 that the symbol t has not reached the last symbol of the frame, the symbol t is incremented in step S28, and the flow returns to step S23. Then, the forced phase synchronization processing for each symbol of the signal subjected to the adaptive array processing is performed until the symbol of the frame ends (t = 1).
(Until it reaches 20).

Returning to FIG. 2, the DSP 10 executes differential decoding processing after forced phase synchronization processing.

This processing detects a phase change between two consecutive symbols in the time series of the signal whose phase has been forcibly synchronized, and performs detection based on the correspondence between a predetermined phase difference and demodulated data. The 2-bit data corresponding to the phase change is output as demodulated data. That is, if there are four patterns of phase differences, 00, 01, 10, 1
It is possible to output four 2-bit data of 1.

In the example of FIG. 2, when the phase difference Δθ between two symbols is 3π / 4, 01 demodulated data is output.

FIG. 6 shows such a differential decoding process performed by a DSP.
FIG. 10 is a flowchart showing a process when software 10 executes by software.

Referring to FIG. 6, after the completion of the forced phase synchronization processing of FIG. 5, the differential decoding processing is started.
At 31, the time t is set to the first symbol.

Next, in step S32, the phase difference Δθ between the signal of the symbol at t = 1 and the signal one symbol after the symbol is calculated by the following equation: Δθ = atan (Y (t + 1) / X (t + 1) ) -At
an (Y (t) / X (t)) (atan means arc tangent) Next, in step S33, a conversion table between phase difference and data is obtained (−3π / 4, 11), ( 3π / 4,0
1) Based on (π / 4,00) and (−π / 4,10), demodulated data is generated from the phase difference detected in step S32.

If it is determined in step S34 that the symbol t has not reached the last symbol of the frame, the symbol t is incremented in step S35, and the flow returns to step S32. Then, the differential decoding process for each symbol of the signal is repeatedly executed until the symbol of the frame ends (until t = 120).

As described above, according to the embodiment of the present invention, the adaptive array processing based on the reference signal is first performed, so that a very high-accuracy extracted signal can be obtained after the array processing. This is because, by the adaptive array processing, the phase shift of the desired signal wave itself for each antenna is corrected by multiplication with the weight vector, and the signals are combined and output after each antenna has the same phase. At the same time, for the interference wave component, the interference power is canceled by multiplying the phase shift of each antenna by the weight vector.

Since the signal subjected to the adaptive array processing is further subjected to the forced phase synchronization to the reference signal point and the differential decoding processing, a complicated circuit such as a carrier recovery circuit as in the conventional synchronous detection system is used. A demodulated signal with high accuracy can be obtained in the same manner as at the time of synchronous detection without providing a simple hardware configuration.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0083]

As described above, according to the present invention, a complicated hardware configuration required in the conventional synchronous detection system is not provided, and an accuracy equivalent to the synchronous detection system is obtained in comparison with the conventional delay detection system. , The received signal can be demodulated.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a hardware configuration of a CS receiver according to the present invention.

FIG. 2 is a diagram for explaining overall processing of the DSP according to the embodiment of the present invention;

FIG. 3 is a functional block diagram for functionally explaining adaptive array processing by the DSP according to the embodiment of the present invention;

FIG. 4 is a flowchart showing processing when the DSP executes the operation of the functional block diagram of the adaptive array shown in FIG. 3 by software.

FIG. 5 is a flowchart showing processing when a DSP executes forced phase synchronization processing by software according to an embodiment of the present invention.

FIG. 6 is a flowchart showing a process when the DSP executes the differential decoding process by software according to the embodiment of the present invention;

FIG. 7 is a schematic block diagram for explaining the principle of a conventional synchronous detection system.

FIG. 8 is a schematic block diagram for explaining the principle of a conventional differential detection system.

[Explanation of symbols]

1 reception filter, 2 multiplier, 3 carrier generation circuit,
4 LPF, 51-bit delay circuit, 10 digital signal processor, 11 reception filter, 20 weight calculation circuit, 21 adder, 22 subtractor.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 5J021 AA05 AA06 AB00 DB03 EA04 FA09 FA13 FA14 FA15 FA16 FA23 FA25 HA05 HA10 HA10 5K004 AA05 FA05 FA14 FG02 5K059 CC03 CC04 DD33 DD37 EE02 5K067 AA02 AA23 BB04 CC24 DD13 DD25 GG51 DD21 KK03

Claims (10)

[Claims] 1. A radio receiving system for receiving a signal from a mobile terminal device using a plurality of antennas, the signal being subjected to an adaptive array process on the received signal to extract a signal from a desired mobile terminal device. Extraction means, forced phase synchronization means for forcibly synchronizing the phase of each symbol point of the extracted signal to the phase of the closest signal reference point among predetermined signal reference points, and Phase change detecting means for detecting a phase change between two symbols; demodulated data output means for outputting data corresponding to the detected phase change as demodulated data based on a predetermined correspondence between the phase difference and the data; , A wireless receiving system. 2. The signal from the mobile terminal device has a predetermined reference signal for each predetermined section, the signal extracting unit calculates a weight vector of the received signal, Means for performing a product-sum operation of a weight vector and the received signal, and outputting the result as a signal from the desired mobile terminal device; and means for storing the predetermined reference signal. The wireless reception system according to claim 1, wherein the calculating unit updates the weight vector so as to reduce a square of an error between the result of the product-sum operation and the stored reference signal. 3. The means for calculating the weight vector, wherein in the section of the received signal with the reference signal,
Based on the stored reference signal, the weight vector is updated using an RLS algorithm or an LMS algorithm. In the section of the received signal without the reference signal,
The wireless reception system according to claim 2, wherein the weight vector is updated using an LMS algorithm or an RLS algorithm based on a reference signal calculated backward from a previously calculated weight vector. 4. The method according to claim 1, wherein the predetermined signal reference points are eight reference points of π / 4 shift QPSK, each of which is composed of two sets of four points which are alternately alternated for each symbol. 4. The wireless receiving system according to any one of 3. 5. The predetermined correspondence between the phase difference and data is (-3π / 4,11), (3π / 4,01), (π
The wireless receiving system according to claim 1, wherein the wireless receiving system is (/ 4, 00) or (-π / 4, 10). 6. A detection method in a wireless reception system for receiving a signal from a mobile terminal device using a plurality of antennas, wherein the signal is subjected to an adaptive array process on the received signal to generate a signal from a desired mobile terminal device. Extracting, forcibly synchronizing the phase of each symbol point of the extracted signal with the phase of the closest signal reference point among predetermined signal reference points, and 2 symbols of the phase-synchronized signal. A detection method, comprising: detecting a phase change between the two; and outputting data corresponding to the detected phase change as demodulated data based on a predetermined correspondence between the phase difference and the data. 7. The signal from the mobile terminal device has a predetermined reference signal for each predetermined section, and the step of extracting the signal includes: a step of calculating a weight vector of the received signal. Performing a sum-of-products operation of the weight vector and the received signal, and outputting the result as a signal from the desired mobile terminal device; and storing the predetermined reference signal. The step of calculating the vector is performed by calculating the error of the product-sum operation and the stored reference signal.
7. The detection method according to claim 6, wherein the weight vector is updated so as to reduce the power. 8. The step of calculating the weight vector, wherein in the section of the received signal where the reference signal is present,
Based on the stored reference signal, the weight vector is updated using an RLS algorithm or an LMS algorithm. In the section of the received signal without the reference signal,
The detection method according to claim 7, wherein the weight vector is updated using an LMS algorithm or an RLS algorithm based on a reference signal calculated backward from a previously calculated weight vector. 9. The method according to claim 6, wherein the predetermined signal reference points are eight reference points of π / 4 shift QPSK, each of which is composed of two sets of four points, one set alternately for each symbol. 9. The detection method according to any one of 8. 10. The predetermined correspondence between the phase difference and data is (-3π / 4,11), (3π / 4,01),
The detection method according to any one of claims 6 to 9, wherein (π / 4,00) and (-π / 4,10).