JP3935750B2 - Wireless receiver, reception response vector estimation method, and reception response vector estimation program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radio reception apparatus, a reception response vector estimation method, and a reception response vector estimation program, and more particularly to a radio reception apparatus for estimating a reception response vector of a signal received from a mobile terminal apparatus in a base station of a mobile communication system. The present invention relates to a reception response vector estimation method and a reception response vector estimation program.
[0002]
[Prior art]
In recent mobile communication systems (for example, Personal Handyphone System: hereinafter referred to as PHS), a base station radio receiving apparatus estimates a response vector of each user's mobile terminal apparatus.
[0003]
Here, the response vector (Steering Vector) represents information related to the amplitude and phase of the signal from each mobile terminal device among the signal components from the mobile terminal device received by the radio reception device of the base station. In the wireless reception device, by estimating the response vector for each mobile terminal device, the propagation path characteristics of the wireless section from each mobile terminal device to the wireless reception device of the base station, the power value at the time of signal reception, etc. It becomes possible to detect.
[0004]
In particular, in an adaptive array radio receiver that controls the directivity of signal radio wave transmission and reception by adjusting the amplitude and phase components of signals transmitted and received by multiple antennas of the base station, the amplitude of each antenna The adjustment of the and phase components is essentially done by calculating a weight vector based on the estimated response vector.
[0005]
Conventionally, as a method of estimating a response vector (reception response vector) of a signal received at each base station from each mobile terminal apparatus, a received signal (IQ signal) received for each antenna of the base station, There has been proposed a method of performing estimation by performing complex multiplication on a remodulated signal of demodulated bit data and performing ensemble averaging (time averaging) of the result. This method will be described in detail later.
[0006]
[Problems to be solved by the invention]
However, in such a conventional reception response vector estimation method, when a mobile terminal device of a plurality of users has a path division multiple access (hereinafter referred to as PDMA) to the base station, a reception signal (IQ of each antenna) Signal) and the re-modulated signal from the desired mobile terminal device is the correlation between the re-modulated signal from the desired mobile terminal device and the received signal from the other mobile terminal device connected in multiple connections. It will contain a value term.
[0007]
Such a correlation value term is expected to be zero if the signal components to be subjected to complex multiplication are completely random in time series or if the above-described ensemble averaging is performed sufficiently.
[0008]
However, in practice, there is no guarantee that the signal components to be complex-multiplied are random in time series, and it is difficult to take a long-term ensemble average due to various limitations on signal processing in mobile communication systems. Yes (usually about 20 symbol periods at most).
[0009]
For this reason, the correlation value term between the remodulated signal of the desired user and the received signal of the other user remains without being erased even after the ensemble averaging process, and is included in the estimation result of the received response vector as a surplus component. Become.
[0010]
Therefore, the conventional reception response vector estimation method has a problem that it is difficult to estimate the reception response vector with high accuracy because such surplus components remain after the ensemble averaging process.
[0011]
SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a radio reception apparatus, a reception response vector estimation method, and a reception response vector estimation program that can estimate a reception response vector with a small amount of calculation and high accuracy.
[0012]
[Means for Solving the Problems]
According to one aspect of the present invention, there is provided a wireless reception device that receives signals from a plurality of mobile terminal devices using a plurality of antennas, and the reception timing difference of the signals from the plurality of mobile terminal devices is a symbol period. It is an integer multiple. The wireless reception device includes a signal extraction unit, a correlation value calculation unit, a correlation value selection unit, and a calculation unit. The signal extraction means performs adaptive array processing on signals from a plurality of mobile terminal apparatuses received by a plurality of antennas, and converts the signals from the plurality of mobile terminal apparatuses at any one of a plurality of predetermined reference signal points for each symbol. Extract. The correlation value calculation means specifies the cross-correlation value of the signals from the plurality of mobile terminal apparatuses extracted for each symbol by the signal extraction means as one of a plurality of predetermined reference signal points for each symbol. The correlation value selection unit selects a combination of cross-correlation values that is (0 + 0j) when averaged in combination among a plurality of cross-correlation values calculated corresponding to each symbol by the correlation value calculation unit. The computing means estimates a reception response vector for each symbol corresponding to the selected combination of cross-correlation values.
[0013]
Preferably, the wireless reception device has a combination number determination unit that determines whether or not the number of combinations of cross-correlation values that are (0 + 0j) when combined and averaged is equal to or greater than a predetermined number, and when combined and averaged And (0 + 0j) further including estimation permission means for allowing the calculation means to estimate the reception response vector when the number of combinations of cross-correlation values is equal to or greater than a predetermined number.
[0014]
Preferably, the wireless reception device includes timing difference determination means for determining whether or not a reception timing difference of signals from a plurality of mobile terminal devices is an integral multiple of a symbol period, and reception of signals from the plurality of mobile terminal devices. A transmission timing control means for controlling transmission timings for a plurality of mobile terminal apparatuses so that a reception timing difference of signals from the plurality of mobile terminal apparatuses is an integer multiple of the symbol period if the timing difference is not an integer multiple of the symbol period; Is further provided.
[0015]
Preferably, the transmission timing control means, when each of the plurality of mobile terminal devices corresponds to a unique known reference signal, the transmission timing so that the reception timing difference of the signals from the plurality of mobile terminal devices becomes zero. To control.
[0016]
Preferably, the correlation value selection unit multiplies the cross-correlation value calculated corresponding to a certain symbol by the correlation value calculation unit by (−1 + 0j), and a mutual value having the same value as the multiplication result of the multiplication unit. Symbol specifying means for specifying another symbol for which a correlation value has been calculated, and selection means for selecting a cross-correlation value for each of a certain symbol and another symbol as a combination of cross-correlation values.
[0017]
Preferably, the correlation value selection unit terminates the selection operation when the number of selected combinations of cross-correlation values reaches a predetermined number sufficient for estimation of the reception response vector.
[0018]
According to another aspect of the present invention, there is provided a reception response vector estimation method in a radio reception apparatus that receives signals from a plurality of mobile terminal apparatuses using a plurality of antennas, wherein signals of the plurality of mobile terminal apparatuses are received. The reception timing difference is an integral multiple of the symbol period. The reception response vector estimation method performs adaptive array processing on signals from a plurality of mobile terminal apparatuses received by a plurality of antennas, and converts signals from the plurality of mobile terminal apparatuses to any one of a plurality of predetermined reference signal points for each symbol. Extracting the cross-correlation values of the signals from the plurality of mobile terminal apparatuses extracted for each symbol as one of a plurality of predetermined reference signal points for each symbol, and for each symbol A step of selecting a combination of cross-correlation values that becomes (0 + 0j) when averaged in combination among a plurality of cross-correlation values calculated correspondingly, and symbols respectively corresponding to the selected combination of cross-correlation values And calculating a reception response vector.
[0019]
Preferably, the reception response vector estimation method includes a step of determining whether or not the number of combinations of cross-correlation values that become (0 + 0j) when averaged in combination is greater than or equal to a predetermined number, and when averaged in combination A step of permitting estimation of a reception response vector when the number of combinations of cross-correlation values to be (0 + 0j) is a predetermined number or more.
[0020]
Preferably, in the reception response vector estimation method, a step of determining whether or not a difference in reception timing of signals from a plurality of mobile terminal apparatuses is an integral multiple of a symbol period, and a reception timing of signals from the plurality of mobile terminal apparatuses If the difference is not an integral multiple of the symbol period, the method further includes a step of controlling transmission timings for the plurality of mobile terminal apparatuses such that a difference in reception timing of signals from the plurality of mobile terminal apparatuses is an integral multiple of the symbol period.
[0021]
Preferably, the step of controlling the transmission timing is performed such that when the plurality of mobile terminal apparatuses correspond to specific known reference signals, the reception timing difference of the signals from the plurality of mobile terminal apparatuses becomes zero. Control transmission timing.
[0022]
Preferably, the step of selecting a combination of cross-correlation values includes a step of multiplying a cross-correlation value calculated corresponding to a certain symbol by (−1 + 0j), and a cross-correlation value having the same value as the multiplication result is calculated. Identifying the selected other symbols, and selecting a cross-correlation value for each of the symbol and the other symbols as a combination of cross-correlation values.
[0023]
Preferably, the step of selecting the combination of cross-correlation values terminates the selection operation when the number of the selected cross-correlation value combinations reaches a predetermined number sufficient to estimate the reception response vector.
[0024]
According to still another aspect of the present invention, there is provided a reception response vector estimation program in a radio reception apparatus that receives signals from a plurality of mobile terminal apparatuses using a plurality of antennas, The reception timing difference is an integral multiple of the symbol period. The reception response vector estimation program performs adaptive array processing on signals from a plurality of mobile terminal apparatuses received by a plurality of antennas on a computer, and converts signals from the plurality of mobile terminal apparatuses into a plurality of predetermined reference signals for each symbol. Extracting at any of the points, identifying the cross-correlation values of the signals from the plurality of mobile terminal devices extracted for each symbol as any of a plurality of predetermined reference signal points for each symbol, and Selecting a cross-correlation value combination that is (0 + 0j) when combined and averaged among a plurality of cross-correlation values calculated corresponding to the symbols of And calculating a reception response vector for the corresponding symbol.
[0025]
Preferably, the reception response vector estimation program determines whether or not the number of combinations of cross-correlation values that are (0 + 0j) when combined and averaged is greater than or equal to a predetermined number, and when combined and averaged When the number of combinations of cross-correlation values that are (0 + 0j) is greater than or equal to a predetermined number, the computer is further caused to execute a step of permitting estimation of a reception response vector.
[0026]
Preferably, the reception response vector estimation program determines whether or not a difference between reception timings of signals from a plurality of mobile terminal apparatuses is an integral multiple of a symbol period, and reception timings of signals from the plurality of mobile terminal apparatuses If the difference is not an integral multiple of the symbol period, the computer further includes a step of controlling transmission timings for the plurality of mobile terminal apparatuses so that a difference in reception timing of signals from the plurality of mobile terminal apparatuses is an integral multiple of the symbol period. Let it run.
[0027]
Preferably, the step of controlling the transmission timing is performed such that when the plurality of mobile terminal apparatuses correspond to specific known reference signals, the reception timing difference of the signals from the plurality of mobile terminal apparatuses becomes zero. Control transmission timing.
[0028]
Preferably, the step of selecting a combination of cross-correlation values includes a step of multiplying a cross-correlation value calculated corresponding to a certain symbol by (−1 + 0j), and a cross-correlation value having the same value as the multiplication result is calculated. Identifying the selected other symbols, and selecting a cross-correlation value for each of the symbol and the other symbols as a combination of cross-correlation values.
[0029]
Preferably, the step of selecting the combination of cross-correlation values terminates the selection operation when the number of the selected cross-correlation value combinations reaches a predetermined number sufficient to estimate the reception response vector.
[0030]
Therefore, according to the present invention, by selecting a combination of cross-correlation values that becomes zero when time-averaged in combination and calculating a reception response vector in a symbol corresponding to the combination, It is possible to prevent the surplus correlation value from remaining, and to realize a highly accurate reception response vector estimation with a small amount of calculation.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.
[0032]
In the mobile communication system (PHS) as the background of the present invention, in order to improve the frequency utilization efficiency of radio waves, the same time slot of the same frequency is spatially divided to pass the mobile terminal device of multiple users to the base station. It is assumed that a PDMA system capable of multiple connection is adopted.
[0033]
In this PDMA system, signals from each user's mobile terminal apparatus are separated and extracted by known adaptive array processing.
[0034]
The background of the present invention will be described below. First, a general reception response vector estimation method will be described.
[0035]
For example, it is assumed that the base station has four antennas and user 1 and user 2 are path-multiplexed as in the example of FIG. 5 described later.
[0036]
In this case, the reception response vector H1 of the user 1 and the reception response vector H2 of the user 2 are expressed by the following equations.
[0037]
H1 = [h11, h21, h31, h41]
H2 = [h12, h22, h32, h42]
Here, it is assumed that user 1 is a desired user to be extracted and user 2 is an interference user. For example, among the reception response vectors h11 and h12 of the antenna 1, h11 is the reception response vector of the desired user, and h12 is the reception response vector of the interference user.
[0038]
On the other hand, the signals received by the four antennas are X1 (t), X2 (t), X3 (t), and X4 (t), and the received signals of user 1 and user 2 are S1 (t). , S2 (t), the received signal of each antenna is expressed by the following equation.
[0039]
X1 (t) = h11 · S1 (t) + h12 · S2 (t) + N1 (t)
X2 (t) = h21 · S1 (t) + h22 · S2 (t) + N2 (t)
X3 (t) = h31 · S1 (t) + h32 · S2 (t) + N3 (t)
X4 (t) = h41 · S1 (t) + h42 · S2 (t) + N4 (t)
Here, N1 (t), N2 (t), N3 (t), and N4 (t) are noise components.
[0040]
The reception response vector of the desired user 1 is obtained by the adaptive array processing after successfully receiving each of the reception signals X1 (t), X2 (t), X3 (t), and X4 (t) of the four antennas. Complex conjugate S1 of signal S1 (t) obtained by remodulating the received signal of desired user 1 ^* By averaging the product with (t) for a certain period of time, that is, by taking the ensemble average E, the following equation is obtained.
[0041]
E [X1 (t) ・ S1 ^* (t)] = E [h11 · S1 (t) · S1 ^* (t) + h12 ・ S2 (t) ・ S1 ^* (t) + N1 (t) ・ S1 ^* (t)] ... (1)
E [X2 (t) ・ S1 ^* (t)] = E [h21 · S1 (t) · S1 ^* (t) + h22 ・ S2 (t) ・ S1 ^* (t) + N2 (t) ・ S1 ^* (t)] ... (2)
E [X3 (t) ・ S1 ^* (t)] = E [h31 · S1 (t) · S1 ^* (t) + h32 ・ S2 (t) ・ S1 ^* (t) + N3 (t) ・ S1 ^* (t)] ... (3)
E [X4 (t) ・ S1 ^* (t)] = E [h41 · S1 (t) · S1 ^* (t) + h42 ・ S2 (t) ・ S1 ^* (t) + N4 (t) ・ S1 ^* (t)] ... (4)
Here, the received signal S1 (t) and its complex conjugate, S1 ^* The ensemble average with (t) is E [S1 (t) · S1 ^* (t)] = 1. Further, S1 which is a complex conjugate of the noise component Nn (t) random in time series and the received signal S1 (t). ^* The average ensemble with (t) is E [Nn (t) · S1 ^* (t)] = 0.
[0042]
Therefore, the above equations (1) to (4) are expressed as the following equations (5) to (8), respectively.
[0043]
E [X1 (t) ・ S1 ^* (t)] = h11 + h12 · E [S2 (t) · S1 ^* (t)] ... (5)
E [X2 (t) ・ S1 ^* (t)] = h21 + h22 · E [S2 (t) · S1 ^* (t)] ... (6)
E [X3 (t) ・ S1 ^* (t)] = h31 + h32 · E [S2 (t) · S1 ^* (t)] ... (7)
E [X4 (t) ・ S1 ^* (t)] = h41 + h42 · E [S2 (t) · S1 ^* (t)] ... (8)
Here, the complex conjugate S1 of the received signal S2 (t) of the other user 2 and the modulated signal of the desired user 1 ^* Ensemble average with [t] E [S2 (t) ・ S1 ^* If (t)] becomes zero, the reception response vector H1 = [h11, h21, h31, h41] of the user 1 is obtained as in the following equations (9) to (12).
[0044]
h11 = E [X1 (t) · S1 ^* (t)] ... (9)
h21 = E [X2 (t) · S1 ^* (t)] ... (10)
h31 = E [X3 (t) · S1 ^* (t)] ... (11)
h41 = E [X4 (t) · S1 ^* (t)] ... (12)
However, the term E [S2 (t) · S1 in the equations (5) to (8) ^* (t)] is not necessarily zero. This is because there is no guarantee that the signal S1 (t) and the signal S2 (t) are uncorrelated in time series. Therefore, long term (over a large number of data symbols) time average is required to make this term completely zero.
[0045]
However, as described above, due to the time restriction on the signal processing of the system, it is not possible to take a sufficiently long time average (of the number of symbols) (as described above, with a data period of about 20 symbols at most). is there).
[0046]
In practice, the term E [S2 (t) · S1 ^* (t)] can be considerably reduced, but if the interference component S2 (t) is large in the first place, E [S2 (t) · S1 ^* (t)] remains as a relatively large term.
[0047]
Therefore, such surplus term E [S2 (t) · S1 ^* (t)] remains in the equations (5) to (8), the estimated reception response vector does not become the above equations (9) to (12), and the estimation accuracy of the reception response vector is It will deteriorate.
[0048]
In the conventional method, an arbitrary multiple symbol period is used as the ensemble average period, and therefore, the surplus term E [S2 (t) · S1 within a limited period. ^* It was difficult to make (t)] zero.
[0049]
In contrast, in the present invention, S2 (t) · S1 ^* A combination of data symbols such that when the time average of (t) is taken, the result is zero is found in advance, and the reception response vector is calculated (averaged) for such symbols. Is. As a result, the cross-correlation value (E [S2 (t) · S1) of signals between users (desired user and interfering user) ^* (t)]) remaining (influence on the reception response vector) can be suppressed, and a highly accurate reception response vector can be estimated with a small amount of calculation.
[0050]
The basic principle of the reception response vector estimation method according to the present invention will be described below with reference to FIGS.
[0051]
As described above, the basic principle of the present invention is that the surplus term E [S2 (t) · S1 which is the time average of the cross-correlation values of signals between users. ^* (t)] is found to be zero (that is, 0 + 0j) and a combination of canceling components is found, and the averaging process is performed in the data period.
[0052]
Such a method will be described by taking, as an example, a case where two users are path-multiplexed under the π / 4 shift QPSK (Quaternary Phase Shift Keying) modulation method employed in PHS and the like.
[0053]
FIG. 1 is a diagram showing the arrangement of reference signal points A to H in the π / 4 shift QPSK modulation system, and FIG. 2 is a table showing patterning (I, Q coordinates) of these reference signal points A to H. . In the π / 4 shift QPSK modulation method, each symbol point always has a true signal point at any of eight reference signal points A to H on (I, Q) coordinates. Actually, the signal after adaptive array processing from each user is distributed in the vicinity of any one of the reference signal points A to H on the (I, Q) coordinates.
[0054]
Here, when the reception response vector is estimated using the above-described equations (1) to (4), the cross-correlation E [S1 (t) · S1 between the desired users. ^* In order for (t)] to be 1, the sampling of the signal S1 (t) is performed at the timing t corresponding to the reference signal points A to H in FIG. That is, E [S1 (t) · S1 using the data symbol in the case where the signal of the user 1 accurately arrives at any of the reference signal points A to H. ^* (t)] is calculated, E [S1 (t) · S1 ^* (t)] = 1 is obtained.
[0055]
When the base station arrival timing of the desired user 1 and the interfering user 2 is an integer multiple of the symbol period, the signal of the user 2 is any of the reference signal points A to H at the sampling timing t of the signal S1 (t). It has come to crab.
[0056]
FIG. 3 shows cross-correlation values S2 (t) · S1 depending on signal points that can be taken by the signal S1 (t) of the user 1 and the signal S2 (t) of the user 2 and combinations thereof. ^* It is a table which shows the correspondence of the signal point which (t) can take. As shown in FIG. 3, the signal point where the signal S1 (t) of the user 1 appears is one of the eight reference signal points A to H, and the signal point where the signal S2 (t) of the user 2 appears is also One of eight reference signal points A to H.
[0057]
These cross-correlation values S2 (t) · S1 ^* The output result of (t) eventually becomes one of the eight reference signal points A to H in FIG. 1 as shown in the table of FIG.
[0058]
Here, focusing on FIG. 1 and FIG. 2, when the reference signal points A (1, 0) and E (-1, 0) are averaged, 0 + 0j is obtained. Similarly, when the reference signal points B (0.71, 0.71) and F (−0.71, −0.71) are averaged, 0 + 0j is obtained, and the reference signal points C (0, 1) and G (0 , -1) is 0 + 0j, and the reference signal points D (-0.71, 0.71) and H (0.71, -0.71) are averaged to 0 + 0j.
[0059]
Therefore, the surplus term E [S2 (t) · S1 ^* (t)] is set to zero, a combination of signal points (corresponding to the above (A, E), (B, F), This can be achieved by selecting (C, D), (D, H)) and performing an averaging process.
[0060]
As actual processing, modulated signals S1 (t) and S2 (t) obtained by remodulating the demodulated data (bit strings) extracted by the adaptive array processing of user 1 and user 2 are calculated, and the respective reference signals taken Cross-correlation values S2 (t) and S1 corresponding to points ^* (t) is obtained from the table of FIG. Cross-correlation values S2 (t) · S1 obtained from the table of FIG. ^* Since (t) is at one of the signal points A to H, the cross-correlation value S2 is obtained from the above combinations (A, E), (B, F), (C, D), (D, H). (t) ・ S1 ^* A pair of signal points for canceling (t) is found.
[0061]
E [S2 (t) · S1 which is a surplus term is obtained by obtaining data of signal points of cross-correlation values that are canceled out by averaging in such a combination and performing averaging processing. ^* (t)] can be set to zero, and the reception response vector can be estimated as shown in equations (9) to (12).
[0062]
Next, a method for selecting a combination for canceling the cross-correlation value will be described with reference to FIG. In FIG. 4, time t indicates a data section consisting of 120 symbols of 1 to 120, and calculated modulation signals S1 (t) and S2 (t) and their cross-correlation values corresponding to each symbol. S2 (t) ・ S1 ^* (t) is illustrated.
[0063]
Note that the estimation principle of the present invention is not limited to the case where the number of multiple users is two users, but can be similarly applied when the number of users increases to three users and four users. In the example of FIG. 4, for each symbol, the modulation signal S3 (t) of the third user, user 3, and the cross-correlation values S3 (t) · S1 ^* (t) is further illustrated.
[0064]
Referring to FIG. 5, for example, cross-correlation values corresponding to times (symbols) t = 1 and t = 119 are combined and averaged.
[0065]
User 1 and User 2 cross-correlation values S2 (t) and S1 ^* As for (t), it is the value of signal point A at time t = 1, and the value of signal point E at time t = 119. Therefore, the cross-correlation values S2 (t) · S1 at time t = 1,119. ^* When the average of (t) is taken, the cross-correlation value S2 (t) · S1 ^* (t) is 0 + 0j.
[0066]
Further, the cross-correlation values S3 (t) · S1 of user 1 and user 3 ^* As for (t), it is the value of signal point H at time t = 1, and the value of signal point D at time t = 119. Therefore, the cross-correlation values S3 (t) · S1 at time t = 1,119. ^* When the average of (t) is taken, the cross-correlation value S3 (t) · S1 ^* (t) is 0 + 0j.
[0067]
For example, a procedure for actually obtaining the reception response vector h11 of the user 1 corresponding to the antenna number 1 will be described with reference to the example of FIG. The reception response vector corresponding to antenna number 1 is RV1 (t), and the reception signal at antenna number 1 is RX1 (t).
[0068]
The reception response vector RV1 (1) at time t = 1 is RX1 (1) · S1 at time t = 1. ^* (1) and RX1 (119) · S1 at time t = 119 paired with (1) ^* It is obtained by taking the average with (119). That is, it is expressed as the following equation.
[0069]
RV1 (1) = [RX1 (1) ・ S1 ^* (1) + RX1 (119) ・ S1 ^* (119)] / 2 ... (13)
= [H11 (1) ・ S1 (1) ・ S1 ^* (1) + h12 (1) ・ S2 (1) ・ S1 ^* (1) + h13 (1) ・ S3 (1) ・ S1 ^* (1) + N1 (1) ・ S1 ^* (1) + h11 (119) ・ S1 (119) ・ S1 ^* (119) + h12 (119) ・ S2 (119) ・ S1 ^* (119) + h13 (119) ・ S3 (119) ・ S1 ^* (119) + N1 (119) ・ S1 ^* (119)] / 2
= [H11 {S1 (1) · S1 ^* (1) + S1 (119) ・ S1 ^* (119)}] / 2+ [h12 {S2 (1) · S1 ^* (1) + S2 (119) ・ S1 ^* (119)}] / 2+ [h13 {S3 (1) · S1 ^* (1) + S3 (119) ・ S1 ^* (119)}] / 2+ [N1 (1) · S1 ^* (1) + N1 (119) ・ S1 ^* (119)] / 2
Here, as described above, at time t = 1, 119, the cross-correlation value S2 (t) · S1. ^* When taking the average of (t), the cross-correlation value S2 (t) · S1 ^* (t) is 0 + 0j, and the cross-correlation value S3 (t) · S1 ^* When the average of (t) is taken, the cross-correlation value S3 (t) · S1 ^* (t) is 0 + 0j. Therefore, the reception response vector RV1 (1) is as follows.
[0070]
RV1 (1) = h11 + 0 + 0 + (noise component)
Since the noise component becomes zero when the averaging number is increased, the reception response vector RV1 (1) = h11 is finally obtained.
[0071]
FIG. 5 is a functional block diagram showing an overall configuration of a base station of a mobile communication system (for example, PHS) according to the present invention.
[0072]
Referring to FIG. 5, signals from mobile terminal apparatuses of a plurality of users received by a plurality of base stations, for example, four antennas 1, 2, 3, 4 are transmitted to corresponding transmission / reception circuits 5, 6, 7, Each of the RF circuits 5a, 6a, 7a, and 8a is subjected to reception processing, and further converted into digital signals by the A / D and D / A converters 9, 10, 11, and 12.
[0073]
The four systems of received signals from the respective antennas converted into digital signals are given to a digital signal processor (DSP) 14 via a circulator 13. The inside of the DSP represented by the broken line 14 is a functional block diagram showing processing executed by the DSP in software.
[0074]
The four received signals given to the DSP 14 via the circulator 13 are given to the synchronization processing unit 15 a of the reception processing unit 15.
[0075]
The synchronization processing unit 15a accurately estimates the reception timing of each received signal from a plurality of users (user 1 and user 2 in this example) that are path-multiplex connected to the base station, using a known synchronization position estimation method. Then, the estimated reception timing is given to the reception response vector estimation processing unit 17.
[0076]
The synchronization window control unit 15b performs predetermined synchronization window control on the received signal.
Next, a known adaptive array process is performed on the received signal by the adaptive array processing unit 15c, and the received signals of the users 1 and 2 are separated and extracted using the calculated weights for the users 1 and 2.
[0077]
The separated and extracted signals for each user are demodulated by the detection unit 15d, supplied to the reception response vector estimation processing unit 17 as demodulated data (bit strings) of the users 1 and 2, and output from the DSP 14.
[0078]
The reception response vector estimation processing unit 17 estimates the reception response vector based on the estimation principle described with reference to FIGS. 1 to 4 based on the demodulated bit strings of the users 1 and 2 from the detection unit 15d.
[0079]
In the estimation process, a signal for controlling the transmission timing for the users 1 and 2 is generated based on the reception timings of the users 1 and 2.
[0080]
On the other hand, data to be transmitted by the users 1 and 2 (such as audio data) is given to the modulation processing unit 16 a of the transmission processing unit 16 of the DSP 14. The data of users 1 and 2 modulated by the modulation processing unit 16a are given to one input of multipliers 16b and 16c, respectively.
[0081]
Further, the weights for the users 1 and 2 calculated by the adaptive array processing unit 15c are given to the other inputs of the multipliers 16b and 16c, and the transmission directivity of the data of the users 1 and 2 is determined.
[0082]
The outputs of the multipliers 16b and 16c are given to the transmission timing control unit 16d. The transmission timing control unit 16d adjusts the data transmission timing of the users 1 and 2 based on the transmission timing control signal for the users 1 and 2 given from the reception response vector estimation processing unit 17.
[0083]
The transmission signal synthesis processing unit 16e synthesizes the transmission signals of the users 1 and 2 and converts them into four transmission signals indicated by one arrow in the figure, and the A / D and D / A converters via the circulator 13 Allocate to 9, 10, 11, 12.
[0084]
The four transmission signals converted into analog signals by the A / D and D / A converters 9, 10, 11, and 12 are respectively transmitted to the corresponding RF circuits 5a, 6a, and 6 of the transmission / reception circuits 5, 6, 7, and 8, respectively. Transmission processing is performed at 7a and 8a, and the data is transmitted toward the mobile terminal device via corresponding antennas 1, 2, 3, and 4.
[0085]
[Embodiment 1]
FIG. 6 is a flowchart for explaining a reception response vector estimation method according to the first embodiment of the present invention realized by the DSP 14 of FIG. 5 based on the basic principle described above.
[0086]
Referring to FIG. 6, it is assumed that reception / demodulation processing by adaptive array processing of a plurality of path multiplexed users is completed at the start of processing.
[0087]
First, in step S1, it is determined whether or not there is a reception error in the demodulated data (bit string) of all the multiple users. If even one user has a reception error, the reception response vector cannot be accurately estimated. Therefore, the reception response vector estimation process ends in step S2, and the most recent frame (for example, the previous frame) in which no reception error has occurred. The calculated reception response vector is used as the reception response vector of the current frame.
[0088]
On the other hand, if it is determined in step S1 that there is no reception error in the demodulated data of all multiplex users, it is determined in step S3 whether or not the reception timing difference between all multiplex users is an integral multiple of the symbol period. The
[0089]
If it is determined that this condition is not satisfied, the operation principle of the present invention cannot be realized as described above, so that in step S4, the reception timing difference among all the multiplexed users becomes an integral multiple of the symbol period. Transmission timing control from the base station to the user terminal is executed. Details of the process of step S4 will be described later.
[0090]
By such base station transmission timing control, the multiplicity X of the current time slot (path multiplex connection by the number of multiplexed users X) is realized in step S5. In step S6, this is not the present invention, but described above. The reception response vector is estimated by conventional processing.
[0091]
On the other hand, if it is determined in step S3 that the reception timing difference between all the multiplexed users is an integral multiple of the symbol period, in step S7, processing related to the first user (X = 1) of the X multiplexed users (X = 1) User loop) is set.
[0092]
Next, in step S8, the cross-correlation value between users is specified as one of eight reference signal points from the table shown in FIG. 3, for example, using the demodulated signals of the user X (= 1) and all other users. And ask. For example, as shown in FIG. 4, such processing is performed for each symbol in the entire section of the frame (120 symbols) (where each symbol time is represented by t = 1 to 120), and time t = 1. A table corresponding to each of ~ 120 is created.
[0093]
Then, in step S9, as described above with reference to the table of FIG. 4, a combination for canceling the cross-correlation value (set to 0 + 0j) is searched. Details of the processing in step S9 will be described later.
[0094]
In step S10, as a result of the search in step S9, it is determined whether there is a combination that cancels the cross-correlation value. If there is no such combination, the process proceeds to step S6, and the reception response vector is estimated not by the present invention but by the conventional process described above.
[0095]
On the other hand, if it is determined in step S10 that there is a combination that cancels the cross-correlation value, in step S11, the reception response vectors RV1 (X) to RV4 (X) corresponding to the antenna numbers 1 to 4 are described above. (13) is calculated based on the expansion formula.
[0096]
That is, when a combination of times (a plurality of times from t = 1 to 120) corresponding to the canceled cross-correlation value combination determined in step S9 is represented by z, each received signal of antenna numbers 1 to 4 is represented. Is represented by RX1 (z) to RX4 (z).
[0097]
Similarly, assuming that the demodulated signal of user number X of the user loop is SX (z), the reception response vector of each antenna number is a combination of times z of the multiplication results of the received signal of each antenna and the demodulated signal of the user. Is the sum of That is, it is expressed as follows.
[0098]
RV1 (X) = Σ (RX1 (z) · SX ^* (Z)) ... (14)
RV2 (X) = Σ (RX2 (z) · SX ^* (Z)) ... (15)
RV3 (X) = Σ (RX3 (z) · SX ^* (Z)) ... (16)
RV4 (X) = Σ (RX4 (z) · SX ^* (Z)) ... (17)
A reception response vector vector corresponding to the user X = 1 is calculated by calculating each of these expressions by the cross-correlation value averaging process like the expansion expression of the expression (13).
[0099]
In step S12, it is determined whether or not the user loop X has reached the multiplex number in the current slot. If not, X is incremented by 1 and the process returns to step S8, and the processes from step S8 to step S11 are repeated.
[0100]
Until it is determined in step S12 that X has reached the multiplex number, the processing in steps S8 to S11 is repeated, and a reception response vector for each user is obtained in step S11. In step S12, X is the current slot. If it is determined that the multiplexing number has been reached, the reception response vector estimation process is terminated.
[0101]
Next, FIG. 7 is a flowchart showing a combination search process for canceling the cross-correlation value in step S9 of FIG.
[0102]
First, in step S21, a process (symbol loop) regarding the first symbol (t = 1) of 120 symbols of the frame is set.
[0103]
In step S22, for example, the cross-correlation value between the user X and each of the other users at time t (= 1) in the table of FIG. 4 is set.
[0104]
Next, in step S23, each cross-correlation value at time t (= 1) is multiplied by (−1 + 0j).
[0105]
In step S24, another time t1 in which a cross-correlation value matching the multiplication result in step S23 exists is searched for in the frame (t = 1 to 120).
[0106]
If such a time t1 does not exist in step S24, the process proceeds to step S26. On the other hand, if such a time t1 exists in step S24, then in step S25, the symbol loop t (= 1) and the found time t1 (t = 1 and 119 in the example of FIG. 4) are cross-correlated. Stored as data used for averaging values (ensemble averaging).
[0107]
In step S26, it is determined whether or not the symbol loop t has reached t = 120, that is, whether or not the search has been completed for all of the times t = 1 to 120. If not, t is incremented by 1 and step is performed. Returning to S22, the processing from step S22 to step S25 is repeated.
[0108]
Until it is determined in step S26 that t has reached 120, which is the total number of symbols, the processing in steps S22 to S26 is repeated, and time data for canceling the cross-correlation value is stored in step S25. If it is determined in step S26 that t has reached 120, which is the total number of symbols, and the search has been completed for all times t = 1 to 120, the search process ends.
[0109]
Next, FIG. 8 is a flowchart showing the transmission timing control in step S4 of FIG. As described above, for example, in the case of the π / 4 shift QPSK modulation system, the modulation signal of each user can be sampled at any timing (reference timing) of 8 reference signal points. The principle of the present invention is realized.
[0110]
On the other hand, a signal sampled at a timing slightly deviated from the reference timing does not converge to eight reference signal points, and the principle of the present invention cannot be applied.
[0111]
That is, the principle of the present invention can be applied only when the base station arrival timing difference of each user connected by path multiplexing is an integer symbol multiple, but in other cases, the principle of the present invention cannot be applied. .
[0112]
In general, it is accidental that the difference in base station arrival timing of each user connected by path multiplexing is an integer symbol multiple, and it is considered probabilistically low.
[0113]
That is, in a mobile communication system, it is normally possible that the difference in distance between each of a plurality of mobile terminal apparatuses connected in multiple ways and the base station is large. The reception timing between multiple users in a base station is usually likely to change due to the delay time due to the distance difference.
[0114]
In addition to the time delay due to such a distance difference, the time difference in reception timing may change during reception of the base station due to the difference in characteristics of each mobile terminal apparatus. That is, the standard determines that a mobile terminal apparatus transmits a signal to a base station after a predetermined time from receiving a signal from the base station. A terminal that transmits a transmission signal to the base station earlier than the predetermined time after receiving a transmission signal from the base station, or a terminal that transmits a transmission signal to the base station later than the predetermined time. Exists.
[0115]
Therefore, in order to realize the present invention, it is necessary to make the difference in the reception timings of all users connected in path multiplex connection an integral multiple of the symbol period.
[0116]
As a method for controlling the reception timing from the mobile terminal apparatus in the base station, it is effective to control the transmission timing from the base station to the mobile terminal apparatus.
[0117]
The reason why the reception timing for each user can be controlled by controlling the transmission timing for each user will be described.
[0118]
For example, in a mobile communication system such as PHS, for the timing of signal transmission / reception between a base station and a mobile terminal device, the mobile terminal device is directed to the base station a predetermined time after receiving a signal from the base station. The standard determines that signals are transmitted.
[0119]
That is, if the signal transmission timing is shifted for each user in the base station, the signal reception timing is shifted for each corresponding mobile terminal device. Therefore, the timing for transmitting a signal from each mobile terminal apparatus to the base station is also shifted for each mobile terminal apparatus.
[0120]
As a result, the timing of signal reception from each mobile terminal apparatus in the base station is shifted for each mobile terminal apparatus.
[0121]
In this way, in the base station, by controlling the signal transmission timing for each mobile terminal device, the reception timing from each mobile terminal device in the base station can be indirectly controlled. It is also possible to control the reception timing so as to leave.
[0122]
In general, in the base station, by maximizing the time difference of the transmission timing for a plurality of users that are path-multiplex connected to the same time slot, it is possible to prevent the reception timings from these users from approaching each other, It has been proposed to stabilize the communication quality at the time of path multiplex connection.
[0123]
Referring to FIG. 8, in step S31, the movement position of the transmission timing is calculated by normal base station transmission timing control (for example, maximization of the transmission timing difference described above).
[0124]
Next, in step S32, it is determined whether or not the reception timing difference of all users connected by path multiplexing is an integer multiple of the symbol period. If it is determined that the number is an integral multiple, the process proceeds to step S33, and normal base station transmission timing control (in this example, maximization of the transmission timing difference as described above) is executed.
[0125]
On the other hand, if it is determined in step S32 that the number is not an integral multiple, it is determined in step S34 whether or not users connected by path multiplexing correspond to different unique words (UW).
[0126]
In general, in PHS, UW is a known signal sequence common to all users. For this reason, a plurality of multiple users cannot be separated by UW, and the transmission timing difference needs to be maximized in order to prevent the proximity of reception timings from these users.
[0127]
On the other hand, it can be considered that a plurality of UWs are provided and different UWs are provided for each user. In that case, since multiple users can be separated by UW, it is not necessary to provide a transmission timing difference in the base station.
[0128]
In step S34, it is determined whether or not multiple users are compatible with such multiple UWs. In the case of supporting a plurality of UWs, the reception timings of all the multiplexed users can be separated even if the reception timings of all the multiplexed users are close to each other. Such transmission timing control is performed.
[0129]
On the other hand, if it is determined in step S34 that it does not support a plurality of UWs, the process proceeds to step S36 so that the reception timing difference of all users connected by path multiplexing is an integral multiple (other than 0) of the symbol period. Transmission timing control.
[0130]
As described above, according to the first embodiment of the present invention, a combination of cross-correlation values that becomes zero when combined and averaged is selected from cross-correlation values for each symbol of signals from a plurality of users. Since the reception response vector is calculated for each symbol corresponding to the combination, it is possible to estimate the reception response vector with high accuracy with a small amount of calculation.
[0131]
[Embodiment 2]
In the table of cross-correlation values between users as shown in FIG. 4, when the number of multiple users increases to 3 users and 4 users, the types of cross-correlation values that are combinations of users for each symbol t are also increased. It will increase.
[0132]
On the other hand, the number of symbols in each frame is limited to 120 symbols in PHS, for example, and when the number of multiple users increases, find a combination of cross-correlation values that can be offset within the entire interval of 120 symbols. Becomes difficult. For example, as shown in the example of FIG. 4, when only two symbols (t = 1, 119) can be canceled, noise may be included, and the number of samples for the averaging process may be too small. There is a risk of deterioration of the vector estimation accuracy.
[0133]
On the other hand, there is a problem that even if the number of combinations is too large, the amount of extra calculation increases.
[0134]
Therefore, in the second embodiment of the present invention, the minimum value of the number of cross-correlation value combinations to be subjected to averaging processing (ensemble averaging) is determined in advance, and if the value is less than that value, the control according to the present invention is not performed. It is intended to prevent deterioration of the estimation accuracy of the reception response vector. Also, if the number of combinations reaches a certain number sufficient for estimation, the search is terminated at that time to prevent an increase in the amount of calculation.
[0135]
FIG. 9 is a flowchart for explaining a reception response vector estimation method according to the second embodiment of the present invention realized by the DSP 14 of FIG. 5 based on the principle described above. The flowchart of the second embodiment shown in FIG. 9 is the same as the flowchart of the first embodiment shown in FIG. 6 except for the following points, and the description of the processing of common parts is omitted.
[0136]
That is, the search process in step S40 in FIG. 9 is executed instead of the search in step S9 in FIG. 6, and the determination process for the number of combinations in step S41 in FIG. 9 is performed instead of the determination of the presence / absence of combinations in step S10 in FIG. Is executed.
[0137]
First, in step S40, basically, as in step S9 of FIG. 6, a combination for canceling the cross-correlation value (set to 0 + 0j) is searched. However, in step S40 in FIG. 9, when the number of cross-correlation value combinations reaches a predetermined number, the search process is terminated at that point to prevent an increase in the amount of calculation.
[0138]
FIG. 10 is a flowchart showing the search process in step S40. The flowchart shown in FIG. 10 is the same as the flowchart of the first embodiment shown in FIG. 7 except for the following points, and the description of common parts is omitted.
[0139]
First, in step S51, in addition to the symbol loop setting in step S21 of FIG. 7, the number Z of cross-correlation values (corresponding symbols t) to be subjected to ensemble averaging is set to zero.
[0140]
Then, in step S52, in addition to storing the data (symbol t pair) to be ensemble averaged in step S25 of FIG. 7, the average number Z is incremented by 2 corresponding to the symbol t pair.
[0141]
In step S53, it is determined whether or not the average number Z is equal to or greater than the predetermined value β, in addition to determining whether or not the search has been completed for all times t = 1 to 120 in step S26 of FIG. . The predetermined value β is set to an averaging number that allows the reception response vector to be estimated with a certain accuracy.
[0142]
In step S53, even if the symbol loop t has not reached 120, if the average number Z is equal to or greater than the predetermined value β, the process is terminated at that point to prevent an increase in calculation amount.
[0143]
Next, returning to FIG. 9, in step S41, it is determined whether or not the number of combinations that cancel the cross-correlation value searched in step S40 is equal to or greater than a predetermined value α. The predetermined value α is set to the minimum number that can estimate the reception response vector without causing deterioration in accuracy.
[0144]
If it is determined in step S41 that it is not equal to or greater than the predetermined value α, the process proceeds to step S6, and the reception response vector is estimated by the conventional process described above, not by the present invention.
[0145]
On the other hand, if it is determined in step S41 that the value is greater than or equal to the predetermined value α, the reception response vectors RV1 (X) to RV4 (X) corresponding to the antenna numbers 1 to 4 are determined in step S11 as described above. Calculated.
[0146]
As described above, according to the second embodiment of the present invention, when the number of combinations of cross-correlation values for averaging processing is not sufficient, the reception response vector estimation method according to the present invention is terminated and the estimation accuracy deteriorates. In addition, when the number reaches a certain number, the combination search can be terminated to prevent an increase in the amount of extra calculation.
[0147]
The embodiment disclosed this time should be considered as illustrative in all points 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.
[0148]
【The invention's effect】
As described above, according to the present invention, among cross-correlation values for each symbol of signals from a plurality of mobile terminal apparatuses, a combination of cross-correlation values that becomes zero when combined and time-averaged is selected. Since the reception response vector is calculated for each symbol corresponding to the combination, it is possible to realize a highly accurate reception response vector estimation with a small amount of calculation.
[Brief description of the drawings]
FIG. 1 is a diagram showing an arrangement of reference signal points in a π / 4 shift QPSK modulation method used in the present invention.
FIG. 2 is a diagram showing patterning of reference signal points shown in FIG. 1;
FIG. 3 is a diagram showing a table of cross-correlation values of signal components between users.
FIG. 4 is a diagram showing a table for explaining a method for selecting a combination of cross-correlation values according to the present invention.
FIG. 5 is a functional block diagram showing an overall configuration of a base station according to the present invention.
FIG. 6 is a flowchart showing a reception response vector estimation method according to Embodiment 1 of the present invention.
7 is a flowchart showing a method for selecting a combination of cross-correlation values in the reception response vector estimation method shown in FIG. 6. FIG.
FIG. 8 is a flowchart showing a base station transmission timing control method in the reception response vector estimation method shown in FIG. 6;
FIG. 9 is a flowchart showing a reception response vector estimation method according to Embodiment 2 of the present invention;
10 is a flowchart showing a method for selecting a combination of cross-correlation values in the reception response vector estimation method shown in FIG.
[Explanation of symbols]
1, 2, 3, 4 Antenna, 5, 6, 7, 8 Transmission / reception circuit, 5a, 6a, 7a, 8a RF circuit, 9, 10, 11, 12 A / D and D / A converter, 13 Circulator, 14 DSP, 15 reception processing unit, 15a synchronization processing unit, 15b synchronization window control unit, 15c adaptive array processing unit, 15d detection unit, 16 transmission processing unit, 16a modulation processing unit, 16b, 16c multiplier, 16d transmission timing control unit, 16e Transmission signal synthesis processing unit, 17 Reception response vector estimation processing unit.

Claims (18)

A radio reception apparatus that receives signals from a plurality of mobile terminal apparatuses using a plurality of antennas, wherein a reception timing difference of signals from the plurality of mobile terminal apparatuses is an integer multiple of a symbol period,
Adaptive array processing is performed on signals from the plurality of mobile terminal apparatuses received by the plurality of antennas, and signals from the plurality of mobile terminal apparatuses are extracted at any one of a plurality of predetermined reference signal points for each symbol. Signal extraction means for
Correlation value calculating means for specifying a cross-correlation value of signals from the plurality of mobile terminal devices extracted for each symbol by the signal extraction means as any of the plurality of predetermined reference signal points for each symbol;
Correlation value selection means for selecting a combination of the cross-correlation values that is (0 + 0j) when averaged in combination among the plurality of cross-correlation values calculated corresponding to each symbol by the correlation value calculation means. When,
A radio receiving apparatus comprising: arithmetic means for estimating the reception response vector in symbols respectively corresponding to the selected combination of cross-correlation values. Combination number determination means for determining whether or not the number of combinations of the cross-correlation values that become (0 + 0j) when averaged in combination is equal to or greater than a predetermined number;
An estimation permission unit that permits estimation of a reception response vector by the calculation unit when the number of combinations of the cross-correlation values that are (0 + 0j) when the combination is averaged is equal to or greater than the predetermined number; The wireless receiver according to claim 1. Timing difference determination means for determining whether or not a reception timing difference of signals from the plurality of mobile terminal devices is an integral multiple of a symbol period;
If the reception timing difference of the signals from the plurality of mobile terminal apparatuses is not an integral multiple of the symbol period, the plurality of movements so that the reception timing difference of the signals from the plurality of mobile terminal apparatuses is an integral multiple of the symbol period The radio reception apparatus according to claim 1, further comprising transmission timing control means for controlling transmission timing for the terminal apparatus. When the plurality of mobile terminal devices correspond to specific known reference signals, the transmission timing control means transmits the transmission timing so that a difference in reception timing of signals from the plurality of mobile terminal devices becomes zero. The wireless receiver according to claim 3, wherein the wireless receiver is controlled. The correlation value selection means includes:
Multiplying means for multiplying the cross-correlation value calculated corresponding to a certain symbol by the correlation value calculating means by (−1 + 0j);
Symbol specifying means for specifying other symbols for which the cross-correlation value having the same value as the multiplication result of the multiplication means is calculated;
The radio reception apparatus according to claim 1, further comprising selection means for selecting the cross-correlation value in each of the certain symbol and the other symbol as a combination of the cross-correlation values. 6. The radio reception according to claim 1, wherein the correlation value selection unit terminates the selection operation when the number of selected combinations of the cross-correlation values reaches a predetermined number sufficient for estimation of a reception response vector. apparatus. A reception response vector estimation method in a radio reception apparatus that receives signals from a plurality of mobile terminal apparatuses using a plurality of antennas, wherein a reception timing difference of signals from the plurality of mobile terminal apparatuses is an integral multiple of a symbol period. Yes,
Adaptive array processing is performed on signals from the plurality of mobile terminal apparatuses received by the plurality of antennas, and signals from the plurality of mobile terminal apparatuses are extracted at any one of a plurality of predetermined reference signal points for each symbol. Steps,
Identifying a cross-correlation value of signals from the plurality of mobile terminal devices extracted for each symbol as one of the plurality of predetermined reference signal points for each symbol;
Selecting a combination of the cross-correlation values that is (0 + 0j) when averaged in combination among the plurality of cross-correlation values calculated corresponding to each symbol;
Calculating a reception response vector for each symbol corresponding to the selected combination of cross-correlation values. Determining whether the number of combinations of the cross-correlation values that become (0 + 0j) when averaged in combination is greater than or equal to a predetermined number;
The method of claim 7, further comprising: allowing estimation of the reception response vector when the number of combinations of the cross-correlation values that are (0 + 0j) when the combination is averaged is equal to or greater than the predetermined number. Receiving response vector estimation method. Determining whether a reception timing difference of signals from the plurality of mobile terminal devices is an integral multiple of a symbol period;
If the reception timing difference of the signals from the plurality of mobile terminal apparatuses is not an integral multiple of the symbol period, the plurality of movements so that the reception timing difference of the signals from the plurality of mobile terminal apparatuses is an integral multiple of the symbol period The reception response vector estimation method according to claim 7, further comprising a step of controlling transmission timing for the terminal device. The step of controlling the transmission timing is such that, when each of the plurality of mobile terminal devices corresponds to a unique known reference signal, a difference in reception timing of signals from the plurality of mobile terminal devices becomes zero. The reception response vector estimation method according to claim 9, wherein the transmission timing is controlled. The step of selecting a combination of the cross-correlation values includes
Multiplying the cross-correlation value calculated corresponding to a certain symbol by (−1 + 0j);
Identifying another symbol for which the cross-correlation value having the same value as the multiplication result is calculated;
The reception response vector estimation method according to claim 7, further comprising: selecting the cross-correlation value in each of the certain symbol and the other symbol as a combination of the cross-correlation values. The step of selecting the combination of cross-correlation values terminates the selection operation when the number of selected combinations of the cross-correlation values reaches a predetermined number sufficient for estimation of a reception response vector. The reception response vector estimation method described in 1. A reception response vector estimation program in a radio reception apparatus that receives signals from a plurality of mobile terminal apparatuses using a plurality of antennas, wherein a reception timing difference of signals from the plurality of mobile terminal apparatuses is an integral multiple of a symbol period Yes, on the computer,
Adaptive array processing is performed on signals from the plurality of mobile terminal apparatuses received by the plurality of antennas, and signals from the plurality of mobile terminal apparatuses are extracted at any one of a plurality of predetermined reference signal points for each symbol. Steps,
Identifying a cross-correlation value of signals from the plurality of mobile terminal devices extracted for each symbol as one of the plurality of predetermined reference signal points for each symbol;
Selecting a combination of the cross-correlation values that is (0 + 0j) when averaged in combination among the plurality of cross-correlation values calculated corresponding to each symbol;
And a step of calculating the reception response vector for each symbol corresponding to the selected combination of cross-correlation values. Determining whether the number of combinations of the cross-correlation values that become (0 + 0j) when averaged in combination is greater than or equal to a predetermined number;
The computer is further configured to allow the estimation of the reception response vector when the number of combinations of the cross-correlation values that become (0 + 0j) when the combination is averaged is equal to or greater than the predetermined number. 14. A reception response vector estimation program according to item 13. Determining whether a reception timing difference of signals from the plurality of mobile terminal devices is an integral multiple of a symbol period;
If the reception timing difference of the signals from the plurality of mobile terminal apparatuses is not an integral multiple of the symbol period, the plurality of movements so that the reception timing difference of the signals from the plurality of mobile terminal apparatuses is an integral multiple of the symbol period The reception response vector estimation program according to claim 13 or 14, further causing the computer to execute a step of controlling transmission timing for the terminal device. The step of controlling the transmission timing is such that, when each of the plurality of mobile terminal devices corresponds to a unique known reference signal, a difference in reception timing of signals from the plurality of mobile terminal devices becomes zero. 16. The reception response vector estimation program according to claim 15, which controls transmission timing. The step of selecting a combination of the cross-correlation values includes
Multiplying the cross-correlation value calculated corresponding to a certain symbol by (−1 + 0j);
Identifying another symbol for which the cross-correlation value having the same value as the multiplication result is calculated;
The reception response vector estimation program according to claim 13, further comprising: selecting the cross-correlation value in each of the certain symbol and the other symbol as a combination of the cross-correlation values. The step of selecting the combination of cross-correlation values terminates the selection operation when the number of selected combinations of the cross-correlation values reaches a predetermined number sufficient for estimation of a reception response vector. The reception response vector estimation program described in 1.

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