JP2006333143A - Radio communication apparatus, radio communication system, method of improving reception quality, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suitably remove an effect of frequency offset on communication data. <P>SOLUTION: A base station device 20 includes a reception timing temporary determination section 54 which temporarily determines reception timing of a burst signal containing a first reference signal, communication data and a second reference signal in this order according to the first reference signal, an optimum frequency offset reverse deviation quantity and optimum reception wait determination section 55 which imparts a plurality of given mutually-different frequency offset reverse deviation quantities to the second reference signal respectively, acquires reception quantity information showing reception quality when the 2nd reference signal is received based upon the acquired reception timing as to respective frequency offset deviation quantities, and selects a frequency offset reverse deviation quantity based upon the acquired reception quality information, and a storage/composition/demodulation/decoding section 57 which decides signal points as to communication data based upon the selected frequency offset reverse deviation quantity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus, a wireless communication system, a reception quality improvement method, and a program.

  In a conventional wireless communication system, a frequency offset (shift from a frequency to be originally received) may occur in a received signal due to the Doppler effect or fading. If there is a frequency offset, the reception performance of the signal in the reception-side wireless communication device may be lowered. Since the signal point on the IQ plane of the received signal acquired at the time of sampling is rotated in phase from the original signal point, the possibility of determining an incorrect signal point as the signal point of the received signal is increased. The reception performance will be reduced.

  In order to suppress such a decrease in reception performance, the conventional receiver-side wireless communication device uses a known synchronization timing acquisition reference signal included in the head position of a communication signal transmitted as a burst signal to There is one that performs a frequency offset correction process for correcting a frequency offset of communication data included in a signal. The synchronization timing acquisition reference signal is obtained by calculating the correlation between the reception signal and the stored synchronization timing acquisition reference signal by the reception-side wireless communication apparatus, so that the position of the synchronization timing acquisition reference signal in the reception signal is calculated. By detecting this, the reception timing of communication data included in the burst signal is detected.

  Hereinafter, the frequency offset correction processing will be specifically described on the assumption that the frequency offset for one burst signal is constant. If there is a frequency offset, the phase rotation amount of signal points gradually accumulates from the beginning to the end of the burst signal. When the frequency offset is constant, the increase amount of the phase rotation amount accumulated in this way is a constant value corresponding to the deviation amount of the frequency offset. Therefore, the synchronization timing acquisition reference signal is given a frequency offset reverse shift amount in which the phase rotation amount increases at a constant predetermined rate in the reverse direction so as to cancel the rotation of this signal point. By correcting the communication data based on the frequency offset reverse shift amount where the reception performance is improved, the deterioration of the reception performance due to the frequency offset is suppressed.

Patent Document 1 describes an example of an apparatus for measuring a frequency offset.
JP 2001-69058 A

  The synchronization timing acquisition reference signal is always received before the communication data. In addition, since it is necessary to ensure communication throughput, it is not appropriate to make the synchronization timing acquisition reference signal too long. On the other hand, as described above, the rotation amount of the signal point due to the frequency offset gradually increases from the beginning to the end of the burst signal, so the phase rotation amount of the signal point at the end of the reference signal for synchronization timing acquisition is for synchronization timing acquisition. Even if it is a level that does not affect the reception performance of the reference signal (a level that cannot be detected by the reference signal for synchronization timing acquisition), there may be a phase rotation amount that cannot be ignored at the end of the communication data. In such a case, the influence of the frequency offset on the communication data cannot be appropriately corrected, and the signal reception performance has been lowered.

  The present invention has been made to solve the above problems, and one of its purposes is a radio communication apparatus, a radio communication system, and a reception quality improvement method capable of appropriately removing the influence of a frequency offset on communication data. And providing a program.

  In order to solve the above problems, a wireless communication apparatus according to the present invention receives a burst signal including a portion that is a first reference signal, a portion that is communication data, and a portion that is a second reference signal in this order. Burst signal receiving means, receiving timing acquisition means for acquiring the reception timing of the burst signal based on the first reference signal, and a plurality of given frequency offset reverse biases different from each other with respect to the second reference signal. Receive quality information acquisition means for acquiring reception quality information indicating reception quality when receiving the second reference signal based on the acquired reception timing and for each frequency offset reverse shift amount Selection means for selecting a frequency offset reverse shift amount based on the reception quality information acquired by the reception quality information acquisition means, and the selected frequency Offset based on an inverse shift amount, characterized in that it comprises a communication data signal point determining means for determining the signal point for said communications data.

  According to the present invention, since the second reference signal is received at the reception timing acquired by the first reference signal, the amount of phase rotation due to the frequency offset of the signal point of the second reference signal is the frequency offset for one burst signal. If it is constant, it becomes larger than the first reference signal or the communication data. For this reason, the reception quality of the second reference signal is generally worse than that of the first reference signal or communication data. In the present invention, since the signal point is determined for the portion that is the communication data based on the frequency offset reverse shift amount selected based on the reception quality of the second reference signal, the reception quality of the communication data is at least first. The reception quality of the two reference signals can be improved, and the influence of the frequency offset on the communication data can be appropriately removed.

  In the wireless communication apparatus, the selection unit receives the reception indicated by the acquired reception quality information out of the frequency offset reverse shift amount given when the reception quality information is acquired by the reception quality information acquisition unit. The frequency offset reverse shift amount with the best quality may be selected.

  The wireless communication apparatus further includes storage means for storing communication data included in the burst signal received by the burst signal receiving means, wherein the communication data signal point determination means is the inverse of the selected frequency offset. Based on the shift amount, the signal point for the stored communication data may be determined.

  According to the present invention, since the communication data is stored, the signal about the communication data based on the frequency offset reverse shift amount selected based on the reception quality of the second reference signal received after the communication data. A point can be determined.

  In the wireless communication apparatus, the wireless communication apparatus includes a plurality of antennas, the burst signal receiving unit receives the burst signal arriving at each antenna for each antenna, and the reception timing acquiring unit includes The reception timing of each burst signal is acquired based on the first reference signal included in each burst signal, and the reception quality information acquisition unit performs the following operation on the second reference signal included in each burst signal: A plurality of given frequency offset reverse shift amounts different from each other, and reception quality information indicating reception quality when receiving each of the second reference signals based on the acquired reception timing is represented by each frequency offset. The reverse shift amount is acquired, and the selection unit is configured to operate based on the reception quality information acquired by the reception quality information acquisition unit. A reverse offset amount of several offsets is selected, and the communication data signal point determination means determines a signal point for the portion that is the communication data based on the selected reverse offset amount of the frequency offset, and the wireless communication A reception weight indicating a relationship of the communication data between the antennas based on the frequency offset reverse shift amount when reception quality information indicating a predetermined reception quality is calculated by the reception quality information calculation means Reception weight calculation means for calculating the communication data, and signal combining means for combining the communication data received by the antennas based on the calculated reception weight.

  In this way, in a wireless communication apparatus including an adaptive array antenna composed of a plurality of antennas, communication data received by each antenna after performing signal point determination based on the optimum frequency offset reverse shift amount Therefore, even when an adaptive array antenna is used, the influence of the frequency offset on the communication data can be appropriately removed.

  Further, in the above wireless communication apparatus, based on the reception weight calculated by the reception weight calculation means, transmission power determination means for determining transmission power when transmitting communication data from each antenna, and the determined transmission Communication data transmission means for transmitting communication data from each antenna with electric power may be further included.

  In this way, the calculated reception weight can be reflected in the transmission power when transmitting communication data.

  Also, the wireless communication system according to the present invention includes a transmission means for transmitting a burst signal including a portion that is a first reference signal, a portion that is communication data, and a portion that is a second reference signal in this order. Including a first wireless communication device, burst signal receiving means for receiving the transmitted burst signal, reception timing acquiring means for acquiring the reception timing of the burst signal based on the first reference signal, and the second A plurality of given frequency offset reverse shift amounts different from each other with respect to the reference signal, and reception quality information indicating reception quality when receiving the second reference signal based on the acquired reception timing, Reception quality information acquisition means for acquiring each frequency offset reverse shift amount, and frequency based on the reception quality information acquired by the reception quality information acquisition means Second wireless communication comprising: selection means for selecting a reverse offset deviation amount; and communication data signal point determination means for determining a signal point for the communication data based on the selected frequency offset reverse deviation amount And a device.

  Also, the reception quality improving method according to the present invention is a burst signal reception for receiving a burst signal including a part that is a first reference signal, a part that is communication data, and a part that is a second reference signal in this order. A reception timing acquisition step of acquiring the reception timing of the burst signal based on the first reference signal, and a plurality of given frequency offset reverse deviation amounts different from each other with respect to the second reference signal, respectively. A reception quality information acquisition step for acquiring reception quality information indicating reception quality when receiving the second reference signal based on the acquired reception timing, and for each frequency offset reverse shift amount; and A selection step of selecting a frequency offset reverse shift amount based on the reception quality information acquired in the quality information acquisition step; Based on the frequency offset reverse shift amount, characterized in that it comprises a communication data signal point determining step of determining the signal point for said communications data.

  The program according to the present invention includes a burst signal receiving means for receiving a burst signal including a part that is a first reference signal, a part that is communication data, and a part that is a second reference signal in this order, Receiving timing acquisition means for acquiring the receiving timing of the burst signal based on the first reference signal, giving a plurality of different frequency offset reverse deviation amounts to the second reference signal, respectively, and acquiring The reception quality information indicating the reception quality when receiving the second reference signal based on the received reception timing is acquired by the reception quality information acquisition means and the reception quality information acquisition means for acquiring the frequency offset reverse shift amount. Selecting means for selecting a frequency offset reverse shift amount based on the received reception quality information, based on the selected frequency offset reverse shift amount And characterized by causing a computer to function the communication data signal point determining means for determining the signal point for communication data, as.

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

  FIG. 1 is a configuration diagram of a mobile communication system 10 according to the present embodiment. As shown in the figure, the mobile communication system 10 according to the present embodiment includes a base station apparatus 20, a mobile station apparatus 30, and a communication network 40. The communication network 40 and the mobile station device 30 perform communication via the base station device 20.

  As illustrated in FIG. 2, the base station apparatus 20 includes a control unit 21, a storage unit 22, a wireless communication unit 23, and a network interface unit 24.

  The control unit 21 controls each unit of the base station device 20 and executes processing related to a call, data communication, or packet communication. In addition, by performing a sampling process for determining signal points included in the analog signal, the analog signal is converted into a digital signal and communication data is acquired. Further, a frequency offset removal process for removing the influence of the frequency offset on the received communication signal is also performed. Details will be described later.

  The storage unit 22 operates as a work memory for the control unit 21. The storage unit 22 holds programs and parameters related to various processes performed by the control unit 21. Further, the storage unit 22 also stores a synchronization timing acquisition reference signal and a frequency offset correction reference signal, which will be described later.

  The wireless communication unit 23 includes an aerial line, receives and demodulates a voice signal, a communication packet, and the like from the mobile station device 30 and outputs them to the control unit 21 or according to an instruction input from the control unit 21. Processing such as modulating an audio signal or a communication packet input from the unit 21 and outputting it via an antenna is performed.

  Further, in the present embodiment, the wireless communication unit 23 includes a plurality of antennas, and the base station apparatus 20 uses each antenna as an adaptive array antenna. That is, the base station apparatus 20 acquires a reception weight for determining the directivity with respect to the mobile station apparatus 30 from the received power of the signal received by each antenna. Next, the base station apparatus 20 calculates a transmission weight based on the reception weight. Then, the base station apparatus 20 transmits a signal using radio waves having directivity with respect to the mobile station apparatus 30 based on the calculated transmission weight. In this way, spatial multiplexing using the directivity of radio waves is realized (spatial division multiplexing, SDMA).

  The network interface unit 24 is connected to the communication network 40 and receives an audio signal, a communication packet, and the like from the communication network 40 and outputs them to the control unit 21, or according to an instruction from the control unit 21. A packet or the like is transmitted to the communication network 40.

  In wireless communication, a frequency offset may occur as described above. When this frequency offset occurs, the reception timing shifts and the reception quality deteriorates. Therefore, in this embodiment, in order to remove the influence of the frequency offset on the communication data, the synchronization timing acquisition reference signal (first reference signal), the communication data, and the frequency offset correction reference signal (second reference signal) are used. A burst signal included in this order is used as a communication signal. Then, after temporarily determining the reception timing based on the synchronization timing acquisition reference signal, a frequency offset removal process for removing the influence of the frequency offset is performed based on the synchronization timing acquisition reference signal and the frequency offset correction reference signal. The reception timing and the reception weight are determined.

  More specifically, the reverse shift is forcibly made by the amount corresponding to the frequency offset, and the reverse shift amount (frequency offset reverse shift amount) with the best reception quality is obtained. Then, based on the obtained frequency offset reverse shift amount, the reception timing and the reception weight are determined.

  Hereinafter, the frequency offset removal processing according to the present embodiment will be described in detail with reference to a functional block diagram and a processing flow diagram of the base station apparatus 20.

  FIG. 3 is a functional block diagram showing functional blocks of the base station apparatus 20. As shown in the figure, the base station apparatus 20 functionally includes n (n is an integer of 2 or more) transmission / reception units 51. Further, the base station apparatus 20 includes a synchronization timing acquisition reference signal acquisition unit 52, a frequency offset correction reference signal acquisition unit 53, a reception timing temporary determination unit 54, an optimal frequency offset reverse shift amount, and an optimal reception weight determination. 55, a reception timing determination unit 56, a storage / synthesis / demodulation / decoding unit 57, a transmission weight determination unit 58, and an encoding / modulation / distribution unit 59.

  The transmission / reception unit 51 uses the wireless communication unit 23 to obtain a synchronization timing acquisition reference signal acquisition unit 52, a frequency offset correction reference signal acquisition unit 53, a reception timing temporary determination unit 54, an optimal frequency offset reverse shift amount, and an optimal reception weight. The determination unit 55, the reception timing determination unit 56, the transmission weight determination unit 58, and the encoding / modulation / distribution unit 59 are realized by the control unit 21, and the storage / synthesis / demodulation / decoding unit 57 is realized by the control unit 21 and the storage unit 22. Has been.

  FIG. 5 is a flowchart showing a processing flow of the communication signal correction processing. Hereinafter, the description of each functional block shown in FIG. 3 will be made with reference to FIG.

  Each transmitting / receiving unit 51 includes an antenna, receives a radio signal arriving at the antenna, receives a synchronization timing acquisition reference signal acquisition unit 52, a frequency offset correction reference signal acquisition unit 53, and a storage / combining / demodulating / decoding unit. (S100). Each transmission / reception unit 51 also converts the communication signal input from the encoding / modulation / distribution unit 59 into a radio signal and transmits it from the antenna.

  FIG. 4 is a diagram illustrating a configuration of a radio signal received by the transmission / reception unit 51. The mobile station device 30 transmits a predetermined amount of data as a burst signal. As shown in the figure, the burst signal includes a portion that is a reference signal for synchronization timing acquisition, a portion that is communication data, and a portion that is a reference signal for frequency offset correction in this order. Has been.

  The synchronization timing acquisition reference signal acquisition unit 52 acquires the synchronization timing acquisition reference signal included in the burst signal (S102). Specifically, the correlation between the radio signal and the reference signal for acquiring synchronization timing stored in the storage unit 22 is acquired, and the portion having a high degree of correlation is determined to be the reference signal for acquiring synchronization timing.

  Next, the synchronization timing acquisition reference signal acquisition unit 52 and the reception timing provisional determination unit 54 perform reception timing provisional determination processing for provisionally determining the reception timing of the burst signal (S104).

  Hereinafter, the reception timing provisional determination processing will be specifically described with reference to the processing flowchart shown in FIG. The temporary reception timing determination unit 54 inputs one or more reception timings to the synchronization timing acquisition reference signal acquisition unit 52 (S200, S206). The reference signal acquisition unit for synchronization timing acquisition 52 indicates the correlation between the input vector indicating the radio signal received by each transmission / reception unit 51 and the reference signal for synchronization timing acquisition stored based on each input reception timing. A correlation vector is calculated (S202). Further, a correlation matrix of the input vector is calculated, and based on the correlation vector and the correlation matrix, a least square error indicating an error between the received wireless signal and the stored synchronization timing acquisition reference signal is calculated (S204). The value of the least square error is reception quality information indicating the reception quality of the received radio signal.

  The reception timing provisional determination unit 54 provisionally determines the reception timing at which the least square error becomes the smallest among the reception timings input to the synchronization timing acquisition reference signal acquisition unit 52 as the communication signal reception timing (S208), and the frequency offset This is input to the correction reference signal acquisition unit 53.

  That is, the reception timing provisional determination unit 54 acquires the reception timing indicating the start position of the burst signal and the time interval of the signal points included in the burst signal as described above, and the base station apparatus 20 and the mobile station apparatus 30 Has been able to synchronize.

  The calculation process of the least square error in the synchronization timing acquisition reference signal acquisition unit 52 and the reception timing provisional determination unit 54 described above will be described in more detail using mathematical expressions.

First, an input vector X (i) indicating a radio signal input from the transmission / reception unit 51 to the synchronization timing acquisition reference signal acquisition unit 52 is expressed by Expression (1). Here, i is an integer indicating the sampling time, and x _k (i) indicates an input component at the i-th sampling time in the transmission / reception unit 51-k.

Next, a correlation vector r _Xr (j) indicating a correlation between the input vector and the stored reference signal for synchronization timing acquisition r (i) is expressed by Expression (2). Here, j is an integer indicating the number of the reception timing τ _j input from the reception timing temporary determination unit 54 to the synchronization timing acquisition reference signal acquisition unit 52. M is an integer indicating the length of the reference signal for synchronization timing acquisition.

In addition, the correlation matrix R _XX (m) of the input vector is expressed by Expression (3).

Then, using the correlation vector r _Xr and the correlation matrix R _XX expressed as described above, the least square error E [| e (t) | ² ] is expressed as shown in Expression (4). E [| r (t) | ² ] is the power of the stored reference signal for synchronization timing acquisition.

The synchronization timing acquisition reference signal acquisition unit 52 and the reception timing provisional determination unit 54 obtain the least square error while changing the reception timing τ _j as described above.

  Next, the frequency offset correction reference signal acquisition unit 53 acquires a frequency offset correction reference signal included in the burst signal (S106). Specifically, the reference signal acquisition unit 53 for frequency offset correction uses the reception timing temporarily determined by the reception timing temporary determination unit 54, the length of the burst signal stored in advance and the reference for frequency offset correction in the burst signal. Based on the position of the signal, the reception timing of the reference signal for frequency offset correction is predicted. Then, in the vicinity of the predicted reception timing, the correlation between the radio signal and the synchronization timing acquisition reference signal stored in the storage unit 22 is acquired, and the portion with a high correlation degree is the frequency offset correction reference signal. Judge.

  The synchronization timing acquisition reference signal acquisition unit 52, the frequency offset correction reference signal acquisition unit 53, and the optimum frequency offset reverse deviation amount and optimum reception weight determination unit 55 are configured to calculate the optimum frequency offset reverse deviation amount and the optimum reception weight. The process which determines is performed.

  Hereinafter, the process for determining these will be described in detail with reference to the process flowchart shown in FIG. The optimum frequency offset reverse deviation amount and optimum reception weight determination unit 55 inputs one or more frequency offset reverse deviation amounts to the synchronization timing acquisition reference signal acquisition unit 52 and the frequency offset correction reference signal acquisition unit 53. (S300, S314). The frequency offset reverse shift amount is for canceling the shift amount of the communication signal due to the frequency offset. At this time, it is unclear what amount of frequency offset reverse shift amount should give the reception quality, so the optimal frequency offset reverse shift amount and optimal reception weight determination unit 55 It is preferable to input an offset reverse shift amount.

  The synchronization timing acquisition reference signal acquisition unit 52 is based on each input frequency offset reverse shift amount, and stores a synchronization timing acquisition reference signal stored with an input vector indicating a radio signal received by each transmission / reception unit 51. A correlation vector indicating the correlation with is calculated (S302). Further, a correlation matrix of the input vector is calculated, and based on the correlation vector and the correlation matrix, a least square error indicating an error between the received wireless signal and the stored synchronization timing acquisition reference signal is calculated (S304).

  In addition, the synchronization timing acquisition reference signal acquisition unit 52 calculates the reception weight of the received radio signal based on the correlation vector and the correlation matrix (S306).

  Similarly, the frequency offset correction reference signal acquisition unit 53, based on each input frequency offset reverse shift amount, stores an input vector indicating a radio signal received by each transmitting / receiving unit 51 and a frequency offset correction stored. A correlation vector indicating the correlation with the reference signal is calculated (S308). Further, a correlation matrix of the input vector is calculated, and a least square error indicating an error between the received radio signal and the stored frequency offset correction reference signal is calculated based on the correlation vector and the correlation matrix (S310).

  The optimum frequency offset reverse shift amount and optimum reception weight determination unit 55 acquires the least square error calculated in S304 and the least square error calculated in S310, and calculates an average least square error that is the average of these. (S312).

  The optimum frequency offset reverse deviation amount and optimum reception weight determining unit 55 determines the frequency offset reverse deviation amount with the smallest mean least square error among the input frequency offset reverse deviation amounts, as the frequency offset reverse deviation of the communication signal. The quantity is selected and determined (S316) and input to the reception timing determination unit 56.

  Further, the optimum frequency offset reverse deviation amount and optimum reception weight determination unit 55 decides the reception weight calculated in S306 for the frequency offset reverse deviation amount of the determined communication signal as the optimum reception weight, and stores, combines, The data is input to the demodulation / decoding unit 57 and the transmission weight determination unit 58.

  Calculation processing of least square error and calculation of reception weight in the reference signal acquisition unit 52 for synchronization timing acquisition, the reference signal acquisition unit 53 for frequency offset correction, and the optimal frequency offset reverse shift amount and optimal reception weight determination unit 55 described above. The process will be described in more detail using mathematical expressions.

When the frequency offset reverse shift amount f _p (p is an integer) is given, the correlation vector shown in Expression (2) is transformed as shown in Expression (5) and expressed as a function r _Xr (p) of p. The Note that R _S is a symbol rate. Further, the reception timing is not taken into consideration in the equation (5). Note that, by using r (i) as the frequency offset correction reference signal, the same calculation is performed for the frequency offset correction reference signal.

  Then, using the correlation vector shown in Equation (5), the least square error is calculated by Equation (4).

The reception weight W (p) is calculated by the following equation (6).

The synchronization timing acquisition reference signal acquisition unit 52, the frequency offset correction reference signal acquisition unit 53, and the optimum frequency offset reverse deviation amount and optimum reception weight determination unit 55 perform the frequency offset reverse deviation amount f _{p as described above.} , The least square error and the reception weight are obtained from the synchronization timing acquisition reference signal, and the least square error is similarly obtained from the frequency offset correction reference signal.

  The storage / synthesis / demodulation / decoding unit 57 temporarily stores the received burst signal. Then, based on the input optimum reception weight, the temporarily stored burst signal is synthesized (S110).

  Further, the reception timing determination unit 56 determines the reception timing based on the optimum frequency offset reverse shift amount (S112). As described above, the reception timing indicates the time interval between the start position of the burst signal and the signal points included in the burst signal. Also, if there is a frequency offset, the time interval of the burst signal changes compared to the case where there is no frequency offset by an amount corresponding to the frequency offset, so the reception timing changes. In order to cope with this, the reception timing determination unit 56 determines the reception timing based on the optimal frequency offset reverse shift amount. The reception timing determination unit 56 outputs the determined reception timing to the storage / combination / demodulation / decoding unit 57.

  The storage / synthesizing / demodulating / decoding unit 57 performs demodulation / decoding by determining (sampling) the signal point of the portion that is communication data of the combined burst signal based on the input reception timing ( S112).

  Further, the transmission weight determination unit 58 calculates a transmission weight based on the input optimum reception weight. The transmission weight determined in this process is determined so as to transmit the transmission radio wave with directivity with respect to the transmission source position of the reception radio wave determined based on the optimum reception weight. Specifically, the transmission power at each antenna is determined based on the transmission weight.

  As described above, in the present embodiment, the optimum frequency offset reverse shift amount and the optimum reception weight are determined based on the reference signals before and after the burst signal, and communication data is received based on these. The reception quality of the communication data can be at least equal to or higher than the reception quality of the frequency offset correction reference signal, and the influence of the frequency offset on the communication data can be appropriately removed.

  Further, since the storage / synthesis / demodulation / decoding unit 57 temporarily stores the communication data, the frequency offset reverse shift amount selected based on the reception quality of the frequency offset correction reference signal received after the communication data. Based on the above, it becomes possible to determine signal points for communication data.

  In addition, even when using an adaptive array antenna, the communication point received by each antenna is synthesized after the signal point is determined based on the optimum amount of reverse frequency offset shift, and the communication transmitted from each antenna is used. Since the transmission power of data can be determined, the influence of the frequency offset on the communication data can be appropriately removed.

  The present invention is not limited to the above embodiment. For example, in the above-described embodiment, an example in which the present invention is applied to a base station apparatus using an adaptive array antenna has been described. However, even a single-antenna wireless communication apparatus may cause a frequency offset in a communication signal. The present invention can be applied to any wireless communication device that is compatible.

  Further, when applied to a base station apparatus using an adaptive array antenna, strictly speaking, the frequency offset reverse shift amount is often different for each antenna. Therefore, in calculating the least square error, the least square error may be calculated by giving different frequency offset reverse shift amounts for each antenna.

  Furthermore, although the least square error is used as the reception quality in the above embodiment, the quality calculated based on the digital signal such as the frame error rate is used as the reception quality after the signal point is determined, for example. It is good to do.

1 is a configuration diagram of a mobile communication system according to an embodiment of the present invention. It is a system configuration | structure figure of the base station apparatus which concerns on embodiment of this invention. It is a functional block diagram of the base station apparatus which concerns on embodiment of this invention. It is a burst signal which concerns on embodiment of this invention. It is a flowchart of the process of the base station apparatus which concerns on embodiment of this invention. It is a flowchart of the process of the base station apparatus which concerns on embodiment of this invention. It is a flowchart of the process of the base station apparatus which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Mobile communication system, 20 Base station apparatus, 21 Control part, 22 Storage part, 23 Wireless communication part, 24 Network interface part, 30 Mobile station apparatus, 40 Communication network, 51 Transmission / reception part, 52 Acquisition of reference signal for synchronous timing acquisition 53, frequency offset correction reference signal acquisition unit, 54 reception timing temporary determination unit, 55 optimum frequency offset reverse shift amount and optimum reception weight determination unit, 56 reception timing determination unit, 57 storage / synthesis / demodulation / decoding unit, 58 transmission weight determination unit, 59 encoding / modulation / distribution unit.

Claims (8)

Burst signal receiving means for receiving a burst signal including a portion that is a first reference signal, a portion that is communication data, and a portion that is a second reference signal in this order;
Reception timing acquisition means for acquiring the reception timing of the burst signal based on the first reference signal;
Reception quality indicating reception quality when a plurality of different given frequency offset reverse shift amounts are given to the second reference signal, respectively, and the second reference signal is received based on the acquired reception timing Reception quality information acquisition means for acquiring information for each frequency offset reverse shift amount;
Selection means for selecting a frequency offset reverse shift amount based on the reception quality information acquired by the reception quality information acquisition means;
Communication data signal point determination means for determining a signal point for the communication data based on the selected frequency offset reverse shift amount;
A wireless communication apparatus comprising: The wireless communication device according to claim 1,
The selecting means is the frequency offset reverse bias having the best reception quality indicated by the acquired reception quality information, out of the amount of frequency offset reverse shift given when the reception quality information acquisition means acquires the reception quality information. Select the transfer amount,
A wireless communication apparatus. The wireless communication apparatus according to claim 1 or 2,
Storage means for storing communication data included in the burst signal received by the burst signal receiving means;
Further including
The communication data signal point determination means determines a signal point for the stored communication data based on the selected frequency offset reverse shift amount.
A wireless communication apparatus. The wireless communication device according to any one of claims 1 to 3,
The wireless communication device includes a plurality of antennas,
The burst signal receiving means receives the burst signal arriving at each antenna, for each antenna,
The reception timing acquisition means acquires the reception timing of each burst signal based on the first reference signal included in each burst signal,
The reception quality information acquisition unit gives a plurality of different predetermined frequency offset reverse shift amounts to the second reference signal included in each burst signal, and based on the acquired reception timing, Obtaining reception quality information indicating reception quality when receiving each second reference signal for each frequency offset reverse shift amount;
The selection means selects a frequency offset reverse shift amount based on the reception quality information acquired by the reception quality information acquisition means,
The communication data signal point determination means determines a signal point for a portion that is the communication data based on the selected frequency offset reverse shift amount,
The wireless communication device
Based on the frequency offset reverse shift amount when reception quality information indicating predetermined reception quality is calculated by the reception quality information calculation means, a reception weight indicating a relationship of the communication data between the antennas is calculated. Receiving weight calculating means;
Signal combining means for combining the communication data received at each antenna based on the calculated reception weight;
Further including
A wireless communication apparatus. The wireless communication apparatus according to claim 4, wherein
Transmission power determining means for determining transmission power when transmitting communication data from each antenna based on the reception weight calculated by the reception weight calculating means;
Communication data transmitting means for transmitting communication data from each antenna at the determined transmission power;
A wireless communication apparatus, further comprising: A transmitting means for transmitting a burst signal including a portion that is a first reference signal, a portion that is communication data, and a portion that is a second reference signal in this order;
A first wireless communication device including:
Burst signal receiving means for receiving the transmitted burst signal;
Reception timing acquisition means for acquiring the reception timing of the burst signal based on the first reference signal;
Reception quality indicating reception quality when a plurality of different given frequency offset reverse shift amounts are given to the second reference signal, respectively, and the second reference signal is received based on the acquired reception timing Reception quality information acquisition means for acquiring information for each frequency offset reverse shift amount;
Selection means for selecting a frequency offset reverse shift amount based on the reception quality information acquired by the reception quality information acquisition means;
Communication data signal point determination means for determining a signal point for the communication data based on the selected frequency offset reverse shift amount;
A second wireless communication device including:
A wireless communication system comprising: A burst signal receiving step of receiving a burst signal including a portion that is a first reference signal, a portion that is communication data, and a portion that is a second reference signal in this order;
A reception timing acquisition step of acquiring the reception timing of the burst signal based on the first reference signal;
Reception quality indicating reception quality when a plurality of different given frequency offset reverse shift amounts are given to the second reference signal, respectively, and the second reference signal is received based on the acquired reception timing Receiving quality information acquisition step for acquiring information for each frequency offset reverse shift amount;
A selection step of selecting a frequency offset reverse shift amount based on the reception quality information acquired in the reception quality information acquisition step;
A communication data signal point determination step for determining a signal point for the communication data based on the selected frequency offset reverse shift amount;
A reception quality improvement method comprising: Burst signal receiving means for receiving a burst signal including a portion that is a first reference signal, a portion that is communication data, and a portion that is a second reference signal in this order;
A reception timing acquisition means for acquiring the reception timing of the burst signal based on the first reference signal;
Reception quality indicating reception quality when a plurality of different given frequency offset reverse shift amounts are given to the second reference signal, respectively, and the second reference signal is received based on the acquired reception timing Reception quality information acquisition means for acquiring information for each frequency offset reverse shift amount;
A selection unit that selects a frequency offset reverse shift amount based on the reception quality information acquired by the reception quality information acquisition unit, and a signal point of the communication data based on the selected frequency offset reverse shift amount. Communication data signal point determination means for performing determination,
A program characterized by causing a computer to function.

Images