JP2011097459A - Mimo receiving apparatus - Google Patents

Mimo receiving apparatus Download PDF

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JP2011097459A
JP2011097459A JP2009251009A JP2009251009A JP2011097459A JP 2011097459 A JP2011097459 A JP 2011097459A JP 2009251009 A JP2009251009 A JP 2009251009A JP 2009251009 A JP2009251009 A JP 2009251009A JP 2011097459 A JP2011097459 A JP 2011097459A
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Kaoru Tsukamoto
薫 塚本
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Mitsubishi Electric Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To obtain an MIMO receiving apparatus which performs phase shift correction with a smaller processing amount than before, while maintaining performance. <P>SOLUTION: The MIMO receiving apparatus includes a data/known signal separation part 4 which extracts a data signal and a known signal from a received signal received by receiving antennas 1-1 to 1-M, a phase shift estimation part 11 which estimates the phase shift amount of each signal transmitted form each transmitting antenna based on the known signal, a known signal phase correction part 13 which corrects the phase of propagation path information based on the estimated result of the phase shift amount, a data signal separation means (a channel estimation part 15, a weighting factor creation part 17, a user separation part 19) which separates the signal in which transmitted data signals from each transmitting antenna are intermingled into the data signal for each transmitting antenna, based on the propagating path information after the phase correction, and data phase correction parts 21-1 to 21-N which correct each phase of data signal for each transmitting antenna based on the estimated result of the phase fluctuation amount. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、無線通信システムにおけるMIMO(Multiple Input Multiple Output)受信装置に関する。   The present invention relates to a multiple input multiple output (MIMO) receiver in a wireless communication system.

無線通信システムでは、送受信機における発振器の周波数偏差により、時間方向での位相変動が生じる。また、受信機側でフーリエ変換を行うOFDM(Orthogonal Frequency Division Multiplexing),SC−FDMA(Single Carrier Frequency Division Multiple Access)などのシステムでは、フーリエ変換のタイミングがずれると、周波数方向で位相回転が生じる。   In a wireless communication system, phase variation in the time direction occurs due to the frequency deviation of the oscillator in the transceiver. Also, in systems such as OFDM (Orthogonal Frequency Division Multiplexing) and SC-FDMA (Single Carrier Frequency Division Multiple Access) that perform Fourier transform on the receiver side, phase rotation occurs in the frequency direction when the timing of Fourier transform shifts.

また、送受信アンテナに複数のアンテナを使用するMIMO通信システムでは、各受信アンテナにおける受信信号について、送信信号ごとに、上述した位相変動の補正を行う必要がある。たとえば特許文献1には、MIMO通信システムにおける従来の位相変動の補正処理を適用したMIMO通信装置が記載されている。このMIMO通信装置における補正処理では、各受信アンテナにおいて送信信号ごとに位相回転量を推定し、推定結果を用いて送信信号ごとの補正を行っている。   Also, in a MIMO communication system that uses a plurality of antennas as transmission / reception antennas, it is necessary to correct the phase fluctuation described above for each transmission signal with respect to the reception signal at each reception antenna. For example, Patent Document 1 describes a MIMO communication apparatus to which a conventional phase variation correction process in a MIMO communication system is applied. In the correction processing in this MIMO communication apparatus, the phase rotation amount is estimated for each transmission signal in each reception antenna, and correction for each transmission signal is performed using the estimation result.

特開2009−130702号公報JP 2009-130702 A

しかしながら、上記従来のMIMO通信装置では、各受信アンテナの受信信号(各送信アンテナから送信された信号が混在した状態の信号)に対して位相補正を行っているため、受信アンテナ本数が増大するにつれ、位相補正に要する処理量が増大するという問題があった。   However, in the above conventional MIMO communication apparatus, phase correction is performed on the reception signals of the respective reception antennas (signals in which signals transmitted from the respective transmission antennas are mixed), so that the number of reception antennas increases. There is a problem that the amount of processing required for phase correction increases.

本発明は、上記に鑑みてなされたものであって、仮に受信アンテナが増大した場合においても処理量の増加を従来よりも低く抑え、かつ従来と同等の復調性能を実現するMIMO受信装置を得ることを目的とする。   The present invention has been made in view of the above, and it is possible to obtain a MIMO receiving apparatus that suppresses an increase in the processing amount even when the number of receiving antennas is increased, and realizes demodulation performance equivalent to that of the conventional art. For the purpose.

上述した課題を解決し、目的を達成するために、本発明は、MIMO受信装置であって、各受信アンテナで受信したそれぞれの受信信号から、データ信号と既知信号を抽出するデータ/既知信号分離手段と、前記抽出された既知信号に基づいて、各送信アンテナから送信されたそれぞれの信号の位相変動量を推定する位相変動量推定手段と、前記位相変動量の推定結果に基づいて、前記既知信号に基づき算出された伝搬路情報の位相を補正する既知信号位相補正手段と、前記位相が補正された後の伝搬路情報に基づいて、前記抽出されたデータ信号である、各送信アンテナからの送信データ信号が混在した信号、を送信アンテナごとのデータ信号に分離するデータ信号分離手段と、前記位相変動量の推定結果に基づいて、前記送信アンテナごとのデータ信号それぞれの位相を補正するデータ位相補正手段と、を備えることを特徴とする。   In order to solve the above-described problems and achieve the object, the present invention is a MIMO receiving apparatus, in which a data signal and a known signal are extracted from each received signal received by each receiving antenna. Means, phase fluctuation amount estimation means for estimating the phase fluctuation amount of each signal transmitted from each transmitting antenna based on the extracted known signal, and the known based on the estimation result of the phase fluctuation amount A known signal phase correcting means for correcting the phase of the propagation path information calculated based on the signal, and the extracted data signal from each transmitting antenna based on the propagation path information after the phase is corrected. Data signal separation means for separating a signal in which transmission data signals are mixed into data signals for each transmission antenna, and based on the estimation result of the phase fluctuation amount, Characterized in that it comprises a data phase correcting means for correcting the respective data signal of the phase.

本発明によれば、従来と同等の復調性能を維持しつつ位相変動補正にかかる処理量を削減することができる、という効果を奏する。   According to the present invention, it is possible to reduce the amount of processing required for phase fluctuation correction while maintaining the demodulation performance equivalent to the conventional one.

図1は、本発明にかかるMIMO受信装置の実施の形態1の構成例を示す図である。FIG. 1 is a diagram showing a configuration example of a first embodiment of a MIMO receiving apparatus according to the present invention. 図2は、本発明にかかるMIMO受信装置が受信する信号の構成例を示す図である。FIG. 2 is a diagram illustrating a configuration example of a signal received by the MIMO receiving apparatus according to the present invention. 図3は、本発明にかかるMIMO受信装置の実施の形態2の構成例を示す図である。FIG. 3 is a diagram illustrating a configuration example of the second embodiment of the MIMO receiving apparatus according to the present invention.

以下に、本発明にかかるMIMO受信装置の実施の形態を図面に基づいて詳細に説明する。なお、この実施の形態によりこの発明が限定されるものではない。下記の各実施の形態においては、MIMO受信装置がLTE(Long Term Evolution)の基地局を構成する場合を例にとって説明する。また、各実施の形態では、送信ユーザ数をN(Nは正整数)とし、各ユーザは1アンテナでの送信を行い、基地局のMIMO受信装置においては、M(Mは正整数)本の受信アンテナで受信するものとする。   Embodiments of a MIMO receiving apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In each of the following embodiments, a case will be described as an example where a MIMO receiving apparatus constitutes an LTE (Long Term Evolution) base station. In each embodiment, the number of transmission users is N (N is a positive integer), and each user performs transmission with one antenna. In the MIMO receiver of the base station, M (M is a positive integer) It shall be received by a receiving antenna.

実施の形態1.
図1は、本発明にかかるMIMO受信装置の実施の形態1の構成例を示す図である。図1に示したように、本実施の形態のMIMO受信装置は、複数の受信アンテナ1−1〜1−M、FFT部3、データ/既知信号分離部4、既知信号レプリカ生成部7、既知信号レプリカ乗算部9、位相変動量推定部11、既知信号位相補正部13、チャネル推定部15、重み係数作成部17、ユーザ分離部19および複数のデータ位相補正部21−1〜21−Nを備える。なお、チャネル推定部15、重み係数作成部17およびユーザ分離部19がデータ信号分離手段を構成する。
Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration example of a first embodiment of a MIMO receiving apparatus according to the present invention. As shown in FIG. 1, the MIMO receiving apparatus according to the present embodiment includes a plurality of receiving antennas 1-1 to 1-M, an FFT unit 3, a data / known signal separation unit 4, a known signal replica generation unit 7, a known A signal replica multiplication unit 9, a phase variation estimation unit 11, a known signal phase correction unit 13, a channel estimation unit 15, a weight coefficient creation unit 17, a user separation unit 19 and a plurality of data phase correction units 21-1 to 21-N Prepare. The channel estimation unit 15, the weight coefficient creation unit 17, and the user separation unit 19 constitute a data signal separation unit.

上記構成のMIMO受信装置において、受信アンテナ1−1〜1−Mは、ユーザから送信された信号を受信し、各受信信号に基づいて生成された受信ベースバンド信号2−1〜2−Mは、FFT部3へ入力される。   In the MIMO receiving apparatus configured as described above, the receiving antennas 1-1 to 1-M receive signals transmitted from users, and the reception baseband signals 2-1 to 2-M generated based on the received signals are , Input to the FFT unit 3.

FFT部3は、入力信号を周波数領域の信号に変換し、データ/既知信号分離部4へ出力する。   The FFT unit 3 converts the input signal into a frequency domain signal and outputs the signal to the data / known signal separation unit 4.

データ/既知信号分離部4は、入力信号を既知信号5−1〜5−Mとデータ信号6−1〜6−Mとに分離し、既知信号は既知信号レプリカ乗算部9へ、またデータ信号はユーザ分離部19へ、それぞれ出力する。   The data / known signal separation unit 4 separates the input signal into known signals 5-1 to 5-M and data signals 6-1 to 6-M, and the known signal is transmitted to the known signal replica multiplication unit 9 and the data signal. Are output to the user separation unit 19, respectively.

既知信号レプリカ生成部7は、ユーザ毎の既知信号レプリカ8−1〜8−Nを生成し、既知信号レプリカ乗算部9へ出力する。   The known signal replica generation unit 7 generates known signal replicas 8-1 to 8-N for each user and outputs the known signal replicas 8-1 to 8-N to the known signal replica multiplication unit 9.

既知信号レプリカ乗算部9は、既知信号5−1〜5−Mに対して既知信号レプリカ8−1〜8−Nを乗算し、各ユーザに対する受信アンテナ毎の(各送信アンテナから各受信アンテナまでの伝搬路それぞれについての)伝搬路情報(伝搬路情報10−1−1〜10−1−M,…,10−N−1〜10−N−M)を生成し、生成した各伝搬路情報を位相変動量推定部11へ出力する。   The known signal replica multiplication unit 9 multiplies the known signals 5-1 to 5-M by the known signal replicas 8-1 to 8-N, and obtains each receiving antenna for each user (from each transmitting antenna to each receiving antenna). Propagation path information (propagation path information 10-1-1 to 10-1-M,..., 10-N-1 to 10-N-M) for each of the propagation paths, and the generated propagation path information Is output to the phase variation estimation unit 11.

位相変動量推定部11は、入力された各伝搬路情報に基づいて、各ユーザの送信信号の位相変動量12−1〜12−Nを推定し、既知信号位相補正部13およびデータ位相補正部21−1〜21−Nへ出力する。なお、各位相変動量は、対応するデータ位相補正部へ出力する。また、位相変動量推定部11は、入力された各伝搬路情報を既知信号位相補正部13に対して出力する。   The phase fluctuation amount estimation unit 11 estimates the phase fluctuation amounts 12-1 to 12-N of the transmission signals of the respective users based on the input propagation path information, and the known signal phase correction unit 13 and the data phase correction unit. Output to 21-1 to 21-N. Each phase fluctuation amount is output to the corresponding data phase correction unit. Further, the phase fluctuation amount estimation unit 11 outputs each input propagation path information to the known signal phase correction unit 13.

既知信号位相補正部13は、位相変動量12−1〜12−Nに基づいて、各伝搬路情報の位相を補正し、補正後の各伝搬路情報(伝搬路情報14−1−1,…,14−1−M,…,14−N−1,…,14−N−M)をチャネル推定部15へ出力する。   The known signal phase correction unit 13 corrects the phase of each propagation path information based on the phase fluctuation amounts 12-1 to 12-N, and each corrected propagation path information (propagation path information 14-1-1, ...). , 14-1-M,..., 14-N-1,..., 14-N-M) are output to the channel estimation unit 15.

チャネル推定部15は、入力された補正後の伝搬路情報に基づいて、各ユーザに対する受信アンテナ毎のチャネル推定値(チャネル推定値16−1−1,…,16−1−M,…,16−N−1,…,16−N−M)を生成し、重み係数作成部17へ出力する。   Based on the input channel information after correction, the channel estimation unit 15 estimates the channel estimation value for each user for each receiving antenna (channel estimation values 16-1-1, ..., 16-1-M, ..., 16). -N-1,..., 16-NM) are generated and output to the weighting factor creating unit 17.

重み係数作成部17は、入力されたチャネル推定値に基づいて、ユーザ分離に用いる重み係数(重み係数18−1−1,…,18−1−M,…,18−N−1,…,18−N−M)を生成し、ユーザ分離部19へ出力する。   Based on the input channel estimation value, the weighting factor creation unit 17 uses weighting factors (weighting factors 18-1-1,..., 18-1-M,..., 18-N-1,. 18-N−M) is generated and output to the user separation unit 19.

ユーザ分離部19は、データ/既知信号分離部4から入力されたデータ信号6−1〜6−Mに対して重み係数を乗算してユーザ毎の信号20−1〜20−Nに分離する。信号20−1〜20−Nは対応するデータ位相補正部21−1〜21−Nへ出力される。   The user separation unit 19 multiplies the data signals 6-1 to 6-M input from the data / known signal separation unit 4 by weighting factors to separate the signals 20-1 to 20-N for each user. The signals 20-1 to 20-N are output to the corresponding data phase correction units 21-1 to 21-N.

データ位相補正部21−1〜21−Nは、位相変動量推定部11から入力された位相変動量推定値12−1〜12−Nに基づいて、入力信号20−1〜20−Nの位相を補正し、補正後の信号を復調信号22−1〜22−Nとして出力する。   The data phase correction units 21-1 to 21 -N are based on the phase variation estimation values 12-1 to 12 -N input from the phase variation estimation unit 11 and the phases of the input signals 20-1 to 20 -N. And the corrected signals are output as demodulated signals 22-1 to 22-N.

図2は、本発明にかかるMIMO受信装置が受信する信号の構成例を示す図であり、本実施の形態ではMIMO受信装置がLTEの基地局の場合を想定しているので、LTE上りリンクで規定されているスロットフォーマットを示している。図2では、1サブフレームの信号構成を示しており、このサブフレームは、12個のデータ信号スロット(データ#1〜データ#12)と2個の既知信号スロット(既知信号#1,#2)からなる合計14個のスロットを含んでいる。また、先頭から4番目と11番目に既知信号スロットを配置した構成となっている。   FIG. 2 is a diagram illustrating a configuration example of a signal received by the MIMO receiving apparatus according to the present invention. In this embodiment, since the MIMO receiving apparatus is assumed to be an LTE base station, the LTE uplink is used. The specified slot format is shown. FIG. 2 shows a signal configuration of one subframe, and this subframe includes 12 data signal slots (data # 1 to data # 12) and two known signal slots (known signals # 1 and # 2). ) Including a total of 14 slots. In addition, the fourth and eleventh known signal slots from the top are arranged.

つづいて、図1および図2を参照しながら、本実施の形態のMIMO受信装置の動作について詳細に説明する。   Next, the operation of the MIMO receiving apparatus according to the present embodiment will be described in detail with reference to FIG. 1 and FIG.

基地局(MIMO受信装置)に対しては、送信局である各ユーザ(図示せず)から、図2に示した構成のサブフレーム単位で信号が送信される。このサブフレームにおいては、各データ信号スロットにデータ信号(データシンボル)が、また各既知信号スロットには受信側で送信信号系列が既知である既知信号(既知信号シンボル)が配置されている。ここでは、すべてのユーザからの送信信号を、受信局である基地局が受信するタイミングが同じになるように、すべてのユーザの送信タイミングが制御されているものとする。また、すべてのユーザの使用周波数帯域は同じとし、使用周波数帯域の全てのサブキャリアにデータまたは既知信号が割り当てられているものとする。   Signals are transmitted to the base station (MIMO receiver) from each user (not shown) as a transmitting station in units of subframes having the configuration shown in FIG. In this subframe, a data signal (data symbol) is arranged in each data signal slot, and a known signal (known signal symbol) whose transmission signal sequence is known on the receiving side is arranged in each known signal slot. Here, it is assumed that transmission timings of all users are controlled so that transmission signals from all users are received by the same base station as a receiving station. In addition, it is assumed that the frequency bands used by all users are the same, and data or known signals are allocated to all subcarriers in the frequency bands used.

基地局を構成しているMIMO受信装置において、受信アンテナ1−1〜1−Mは、図示を省略したN個の移動端末(ユーザ)からの送信信号を受信する。各受信アンテナ1−1〜1−Mで受信された信号は、それぞれ、図示しない周波数変換部により、ベースバンド信号2−1〜2−Mに変換される。ベースバンド信号2−1〜2−Mは、FFT部3に渡され、FFT部3は、ベースバンド信号2−1〜2−Mに対してフーリエ変換(Fast Fourier Transform)を実行して周波数領域の信号に変換する。   In the MIMO receiving apparatus constituting the base station, the receiving antennas 1-1 to 1-M receive transmission signals from N mobile terminals (users) (not shown). Signals received by the receiving antennas 1-1 to 1-M are converted into baseband signals 2-1 to 2-M by frequency converters (not shown), respectively. The baseband signals 2-1 to 2-M are passed to the FFT unit 3, and the FFT unit 3 performs a Fourier transform on the baseband signals 2-1 to 2-M to perform frequency domain. Convert to a signal.

周波数領域の信号に変換されたベースバンド信号2−1〜2−Mは、データ/既知信号分離部4に渡され、データ/既知信号分離部4は、受け取った信号を既知信号5−1〜5−Mとデータ信号6−1〜6−Mに分離する。分離処理で得られた既知信号5−1〜5−Mは既知信号レプリカ乗算部9に渡され、データ信号6−1〜6−Mはユーザ分離部19に渡される。   The baseband signals 2-1 to 2-M converted into the frequency domain signals are transferred to the data / known signal separation unit 4, and the data / known signal separation unit 4 converts the received signals into known signals 5-1 to 5-1. 5-M and data signals 6-1 to 6-M are separated. The known signals 5-1 to 5 -M obtained by the separation processing are passed to the known signal replica multiplication unit 9, and the data signals 6-1 to 6 -M are passed to the user separation unit 19.

既知信号レプリカ乗算部9は、データ/既知信号分離部4から受け取った既知信号5−1〜5−Mに対して、既知信号レプリカ生成部7で生成されるユーザ毎の既知信号レプリカ8−1〜8−Nを複素共役乗算し、既知信号5−1〜5−Mのユーザ分離、および伝搬路情報の抽出を行う。抽出された伝搬路情報は各受信アンテナにおけるユーザ毎の伝搬路情報(各ユーザから各アンテナまでのそれぞれの伝搬路情報)であり、伝搬路情報10−1−1〜10−1−M,…,10−N−1〜10−N−Mは、位相変動量推定部11に対して出力される。なお、伝搬路情報10−n−m(n=1,2,…,N、m=1,2,…,M)は、ユーザn(ユーザnの送信装置)から送信されアンテナmで受信された信号に対応する伝搬路情報である。   The known signal replica multiplying unit 9 performs the known signal replica 8-1 for each user generated by the known signal replica generating unit 7 with respect to the known signals 5-1 to 5-M received from the data / known signal separating unit 4. ˜8-N is subjected to complex conjugate multiplication to perform user separation of known signals 5-1 to 5-M and extraction of propagation path information. The extracted propagation path information is propagation path information for each user at each receiving antenna (each propagation path information from each user to each antenna), and propagation path information 10-1-1 to 10-1-M,. , 10-N-1 to 10-N-M are output to the phase variation estimation unit 11. Note that the propagation path information 10-nm (n = 1, 2,..., N, m = 1, 2,..., M) is transmitted from the user n (the transmission device of the user n) and received by the antenna m. Is propagation path information corresponding to the received signal.

位相変動量推定部11は、既知信号レプリカ乗算部9から伝搬路情報を受け取ると、各受信アンテナにおけるユーザ毎の伝搬路情報10−1−1〜10−N−Mに基づいて、各ユーザの送信信号の位相変動量12−1〜12−Nを推定する。なお、位相変動量12−1〜12−Nとして、周波数方向の位相変動量と時間方向の位相変動量をそれぞれ求める。   When the phase variation estimation unit 11 receives the propagation path information from the known signal replica multiplication unit 9, the phase fluctuation amount estimation unit 11 determines each user's propagation path information 10-1-1 to 10-NM based on the propagation path information 10-1-1 to 10-N-M for each user. The phase fluctuation amounts 12-1 to 12-N of the transmission signal are estimated. Note that the phase fluctuation amount in the frequency direction and the phase fluctuation amount in the time direction are respectively obtained as the phase fluctuation amounts 12-1 to 12-N.

ここで、位相変動量12−1〜12−Nの推定方法について詳しく説明する。   Here, the estimation method of the phase fluctuation amounts 12-1 to 12-N will be described in detail.

FFTタイミングが理想的なタイミングからずれると、周波数方向に位相変動が生じる。周波数方向の位相変動量は、次式(1)のように、周波数方向で隣接するサブキャリア間の複素乗算により求めることができる。   When the FFT timing deviates from the ideal timing, phase fluctuation occurs in the frequency direction. The phase fluctuation amount in the frequency direction can be obtained by complex multiplication between subcarriers adjacent in the frequency direction as in the following equation (1).

Figure 2011097459
Figure 2011097459

ただし、Δθは周波数方向における1サブキャリアあたりの位相変動推定量,rst,fは伝搬路情報10−1−1〜10−N−M,t(=0,1,…,Nrs-1)は時間方向の既知信号シンボルのインデックス,f(=0,1,…,NSC-1)はサブキャリア番号,Nrsは時間方向に挿入された既知信号のシンボル数(図2の例であればNrs=2となる),NSCはサブキャリア数である。 Where Δθ is an estimated amount of phase fluctuation per subcarrier in the frequency direction, and rst , f is propagation path information 10-1-1 to 10-NM, t (= 0,1,..., N rs −1 ) Is the index of the known signal symbol in the time direction, f (= 0, 1,..., N SC −1) is the subcarrier number, N rs is the number of symbols of the known signal inserted in the time direction (in the example of FIG. 2) If N rs = 2, N SC is the number of subcarriers.

なお、本実施の形態では、周波数方向の全てのサブキャリアに既知信号が割り当てられていることを想定しているが、飛び飛びのサブキャリアに既知信号が割り当てられている場合には、既知信号が割り当てられている周波数方向で隣接するサブキャリア間の位相変動量を求めた後、求めた位相変動量を「1/(周波数方向既知信号割り当てサブキャリア間隔)」することで、周波数方向における1サブキャリアあたりの位相変動量を推定することができる。   In this embodiment, it is assumed that a known signal is assigned to all subcarriers in the frequency direction. However, when a known signal is assigned to a skipped subcarrier, the known signal is After obtaining the phase fluctuation amount between adjacent subcarriers in the allocated frequency direction, the obtained phase fluctuation amount is “1 / (frequency direction known signal allocation subcarrier interval)”, so that one sub-frequency in the frequency direction is obtained. The amount of phase fluctuation per carrier can be estimated.

また、送信側と受信側における発振器の周波数偏差により、時間方向に位相変動が生じる。時間方向の位相変動量は、次式(2)のように、各サブキャリアにおいて時間方向で隣接するサブキャリア間の複素乗算により求めることができる。   Further, phase fluctuations occur in the time direction due to the frequency deviation of the oscillators on the transmission side and the reception side. The amount of phase variation in the time direction can be obtained by complex multiplication between subcarriers adjacent in the time direction in each subcarrier, as in the following equation (2).

Figure 2011097459
Figure 2011097459

ただし、Δfは時間方向の位相変動量である。式(2)で求められる位相変動量は既知信号割り当てシンボル間の位相変動量であり、本実施の形態で想定しているスロットフォーマット(図2参照)では、既知信号#1を基準としたときの既知信号#2の位相変動量である。各シンボル間の位相変動量は、式(2)を用いて求めた位相変動量を「1/(既知信号割り当てシンボル間隔)」することで求めることができる。図2の例では、既知信号割り当てシンボル間隔は7となるので、本実施の形態では、式(2)を用いて求めた位相変動量を1/7倍すればよい。   However, Δf is the amount of phase fluctuation in the time direction. The phase fluctuation amount obtained by Expression (2) is the phase fluctuation amount between the known signal allocation symbols. In the slot format assumed in the present embodiment (see FIG. 2), when the known signal # 1 is used as a reference. Of the known signal # 2. The amount of phase fluctuation between symbols can be obtained by “1 / (known signal allocation symbol interval)” of the amount of phase fluctuation obtained using equation (2). In the example of FIG. 2, since the known signal allocation symbol interval is 7, in this embodiment, the amount of phase fluctuation obtained using equation (2) may be multiplied by 1/7.

以上の位相変動量推定値は、各受信アンテナで推定した値をユーザ毎に平均する、または、受信品質値が最良の受信アンテナにおける推定値を選択する、または、受信品質値に基づいて、各受信アンテナにおける推定値を重み付け加算することで、時間方向および周波数方向それぞれについて、ユーザ毎に1つの位相変動量12−1〜12−Nを算出する。なお、上記受信品質値としては、各受信アンテナにおいて、信号電力対雑音電力比,受信信号電力などを測定することで求める。位相変動量推定部11は、上記算出した位相変動量(位相変動量推定値)12−1〜12−Nを既知信号位相補正部13およびユーザ分離部19へ出力する。また、既知信号位相補正部13に対しては、既知信号レプリカ乗算部9から受け取った伝搬路情報も併せて出力する。   The above phase fluctuation estimation values are averaged for each user for the value estimated at each receiving antenna, or the estimated value at the receiving antenna with the best receiving quality value is selected, or based on the receiving quality value, By weighting and adding the estimated values at the receiving antenna, one phase fluctuation amount 12-1 to 12 -N is calculated for each user in each of the time direction and the frequency direction. The reception quality value is obtained by measuring the signal power to noise power ratio, the received signal power, etc., at each receiving antenna. The phase fluctuation amount estimation unit 11 outputs the calculated phase fluctuation amounts (phase fluctuation amount estimation values) 12-1 to 12 -N to the known signal phase correction unit 13 and the user separation unit 19. Further, the propagation path information received from the known signal replica multiplication unit 9 is also output to the known signal phase correction unit 13.

既知信号位相補正部13は、位相変動量推定部11で推定されたユーザ毎の位相変動量12−1〜12−Nを受け取ると、位相変動量12−1〜12−Nに基づいて、各受信アンテナ,ユーザ単位で伝搬路情報10−1−1〜10−N−Mの全サブキャリアの位相が同相となるように、伝搬路情報10−1−1〜10−N−Mの位相を補正する。たとえば、図2の既知信号#1のサブキャリア番号0のサブキャリアの位相を基準として、既知信号#1の他のサブキャリアおよび既知信号#2のすべてのサブキャリアの位相を補正する。   When the known signal phase correction unit 13 receives the phase variation amounts 12-1 to 12 -N for each user estimated by the phase variation amount estimation unit 11, each of the known signal phase correction units 13 performs each based on the phase variation amounts 12-1 to 12 -N. The phase of the propagation path information 10-1-1 to 10-NM is set so that the phase of all the subcarriers of the propagation path information 10-1-1 to 10-NM is the same for each receiving antenna and user. to correct. For example, using the phase of the subcarrier of subcarrier number 0 of known signal # 1 in FIG. 2 as a reference, the phases of other subcarriers of known signal # 1 and all subcarriers of known signal # 2 are corrected.

既知信号位相補正部13における伝搬路情報10−1−1〜10−N−Mの位相補正が終了すると、位相補正後の伝搬路情報14−1−1〜14−N−Mはチャネル推定部15に渡され、チャネル推定部15は、各受信アンテナにおけるユーザ毎のチャネル推定値16−1−1〜16−N−Mを伝搬路情報14−1−1〜14−N−Mに基づいて生成する。チャネル推定部15は、位相補正後の伝搬路情報14−1−1〜14−N−Mを時間方向および周波数方向のそれぞれで平均化、または移動平均化、または重み付け補間することでチャネル推定値16−1−1〜16−N−Mを生成する。受信アンテナm,ユ−ザnのチャネル推定値をhmn(m=1〜M,n=1〜N)とすると、チャネル行列Hは次式(3)のように表される。 When the phase correction of the propagation path information 10-1-1 to 10-N-M in the known signal phase correction unit 13 is completed, the propagation path information 14-1-1-1 to 14-NM after the phase correction is the channel estimation unit. 15, the channel estimation unit 15 calculates channel estimation values 16-1-1 to 16 -N-M for each user at each reception antenna based on the propagation path information 14-1-1 to 14 -N-M. Generate. The channel estimator 15 averages the channel information 14-1-1-1 to 14-NM after phase correction in each of the time direction and the frequency direction, or performs a moving average or weighted interpolation to estimate the channel estimation value. 16-1-1 to 16-N-M are generated. Assuming that the channel estimation value of the receiving antenna m and the user n is h mn (m = 1 to M, n = 1 to N), the channel matrix H is expressed by the following equation (3).

Figure 2011097459
Figure 2011097459

チャネル推定部15により生成されたチャネル推定値16−1−1〜16−N−Mは重み係数作成部17に渡され、重み係数作成部17は、後段のユーザ分離部19で使用する重み係数18−1−1〜18−N−Mをチャネル推定値16−1−1〜16−N−Mを用いて算出する。受信アンテナm,ユーザnの重み係数をwmnとし、重み係数18−1−1〜18−N−MをMMSE(Minimum Mean Square Error)規範で作成する場合、重み係数行列Wは次式(4)のように表される。 Channel estimation values 16-1-1 to 16 -N−M generated by the channel estimation unit 15 are passed to the weighting factor creation unit 17, which uses the weighting factor used by the user separation unit 19 at the subsequent stage. 18-1-1-1 to 18-NM are calculated using channel estimation values 16-1-1 to 16-NM. When the weighting factor of the receiving antenna m and the user n is w mn and the weighting factors 18-1-1-1 to 18-NM are created according to the MMSE (Minimum Mean Square Error) standard, the weighting factor matrix W is expressed by the following equation (4 ).

Figure 2011097459
Figure 2011097459

ただし、σ2は干渉電力値,[・]*は複素共役行列,[・]Tは転置行列,Iは単位行列である。また、重み係数18−1−1〜18−N−Mをゼロフォーシングで作成する場合、重み係数行列Wは上式(4)のσ2を0とすることで求められる。 Here, σ 2 is an interference power value, [·] * is a complex conjugate matrix, [·] T is a transposed matrix, and I is a unit matrix. Further, when the weighting coefficients 18-1-1 to 18-NM are created by zero forcing, the weighting coefficient matrix W is obtained by setting σ 2 in the above equation (4) to 0.

ユーザ分離部19は、重み係数作成部17で算出された重み係数18−1−1〜18−N−Mを受け取ると、これをデータ/既知信号分離部4からの入力信号(各受信アンテナにおけるデータ信号6−1〜6−M)に複素乗算することで、ユーザ毎の信号20−1〜20−Nに分離する。各受信アンテナにおけるデータ信号6−mをrm,ユーザ分離後の信号20−nをynとすると、ユーザ分離部19では、次式(5)のようにしてユーザ分離を行う。 Upon receiving the weighting factors 18-1-1 to 18 -N-M calculated by the weighting factor creating unit 17, the user separating unit 19 receives the weighting factors 18-1-1 to 18 -N-M from the input signals from the data / known signal separating unit 4 (at each receiving antenna). Data signals 6-1 to 6-M) are complex-multiplied to separate signals 20-1 to 20-N for each user. If the data signal 6-m at each receiving antenna is r m and the signal 20-n after user separation is y n , the user separation unit 19 performs user separation as shown in the following equation (5).

Figure 2011097459
Figure 2011097459

ユーザ毎の信号(ユーザ分離後の信号)20−1〜20−Nは、それぞれ、対応するデータ位相補正部21−1〜21−Nに渡される。そして、データ位相補正部21−n(n=1〜N)は、ユーザ分離部19から入力された信号20−nに基づいて、位相変動量推定部11から受け取ったユーザ毎の位相変動量12−nの位相を補正する。位相補正は時間方向および周波数方向それぞれに対して行い、位相補正後の信号は、ユーザ毎の復調信号22−nとして出力される。ユーザnの位相補正量をφn,ユーザnの復調信号をy’nとすると、各データ位相補正部では次式(6)のようにして位相補正を行う。 Signals for each user (signals after user separation) 20-1 to 20-N are respectively transferred to corresponding data phase correction units 21-1 to 21-N. The data phase correction unit 21-n (n = 1 to N) receives the phase fluctuation amount 12 for each user received from the phase fluctuation amount estimation unit 11 based on the signal 20-n input from the user separation unit 19. -N phase is corrected. The phase correction is performed in each of the time direction and the frequency direction, and the signal after the phase correction is output as a demodulated signal 22-n for each user. Assuming that the phase correction amount of user n is φ n and the demodulated signal of user n is y ′ n , each data phase correction unit performs phase correction as shown in the following equation (6).

Figure 2011097459
Figure 2011097459

このように、本実施の形態のMIMO受信装置では、既知信号に基づいて位相変動量を推定し、この位相変動量の推定結果を用いて、受信信号をユーザ分離した後の信号に対するユーザ毎の位相補正を行うこととした。すなわち、ユーザ毎の位相変動補正を各受信アンテナにおける受信データ信号ではなく、受信信号をユーザ分離した後の信号に対して実行することとした。これにより、従来と同程度の復調性能を維持しつつ、位相変動補正にかかる処理量を削減することができる。具体的には、本実施の形態で示した方法を適用した場合、位相変動補正に要する処理がN回となるのに対して、各受信アンテナにおける受信データ信号に対して位相変動補正処理を行う場合(従来のMIMO通信装置における位相変動補正処理に相当)にはM×N回の処理が必要になるので、位相変動補正に要する処理量を「1/(受信アンテナ本数)」に削減することができる。   As described above, in the MIMO receiving apparatus according to the present embodiment, the phase fluctuation amount is estimated based on the known signal, and the estimation result of the phase fluctuation amount is used for each user with respect to the signal after separating the received signal from the user. Phase correction was performed. In other words, the phase fluctuation correction for each user is performed not on the reception data signal at each reception antenna but on the signal after the user separation of the reception signal. As a result, it is possible to reduce the amount of processing required for phase fluctuation correction while maintaining demodulation performance comparable to that of the conventional art. Specifically, when the method shown in this embodiment is applied, the processing required for phase fluctuation correction is N times, whereas the phase fluctuation correction process is performed on the received data signal at each receiving antenna. In this case (corresponding to the phase fluctuation correction process in the conventional MIMO communication apparatus), M × N processes are required, so the processing amount required for the phase fluctuation correction is reduced to “1 / (number of receiving antennas)”. Can do.

実施の形態2.
実施の形態2のMIMO受信装置について説明する。図3は、実施の形態2のMIMO受信装置の構成例を示す図である。ただし、実施の形態1のMIMO受信装置(図1参照)と同一の部分(各受信アンテナ〜重み係数作成部17までの部分)については省略している。本実施の形態では、図3を用いて、実施の形態1のMIMO受信装置と異なる部分(ユーザ分離部19以降の処理)について説明を行う。また、説明を簡略化するため、ユーザ数を2,受信アンテナ数を4とした場合の動作について示す。なお、以下の説明においては、必要に応じて、各ユーザをユーザ#1,ユーザ#2と呼んで区別する。
Embodiment 2. FIG.
A MIMO receiving apparatus according to Embodiment 2 will be described. FIG. 3 is a diagram illustrating a configuration example of the MIMO receiving apparatus according to the second embodiment. However, the same parts as those of the MIMO receiving apparatus of Embodiment 1 (see FIG. 1) (the parts from each receiving antenna to the weighting coefficient creating unit 17) are omitted. In the present embodiment, parts different from those of the MIMO receiving apparatus of Embodiment 1 (processing after user separation section 19) will be described using FIG. In order to simplify the description, the operation when the number of users is 2 and the number of reception antennas is 4 is shown. In the following description, each user will be referred to as user # 1 and user # 2 as necessary.

上述した実施の形態1においては、位相変動量12−1〜12−Nとして、複数の受信アンテナによる推定値から、ユーザ毎に1つの値を位相変動量として使用し、ユーザ毎に全受信アンテナにおける位相変動量を同じ値として扱ったが、受信アンテナ毎に位相変動量が大きく異なる場合には、位相変動補正による誤差が生じてしまう。そこで、本実施の形態では、位相変動量が同じ値として扱うことのできる受信アンテナの組が複数あるものとする(各アンテナの位相変動量を同じ値として扱うと問題が生じる場合の実施の形態について説明する)。   In the first embodiment described above, as the phase fluctuation amounts 12-1 to 12-N, one value for each user is used as the phase fluctuation amount from the estimated values obtained by a plurality of receiving antennas, and all the receiving antennas are used for each user. Although the phase fluctuation amount at is treated as the same value, if the phase fluctuation amount differs greatly for each receiving antenna, an error due to phase fluctuation correction occurs. Therefore, in this embodiment, it is assumed that there are a plurality of sets of receiving antennas that can handle the same amount of phase variation (an embodiment in which a problem occurs when the amount of phase variation of each antenna is treated as the same value). Explain).

受信アンテナ間距離が小さいと、位相変動量は大きく変わらないため、受信アンテナ間距離が小さい受信アンテナ同士を1組として、同じ位相変動量を持つ受信アンテナとして扱うことができる。本実施の形態では、一例として、受信アンテナ1−1における位相変動量と受信アンテナ1−2における位相変動量を同じ値として扱うことができ、また、受信アンテナ1−3における位相変動量と受信アンテナ1−4における位相変動量を同じ値として扱うことができる場合について説明を行う。   If the distance between the receiving antennas is small, the amount of phase fluctuation does not change greatly. Therefore, the receiving antennas having a small distance between the receiving antennas can be treated as a pair of receiving antennas having the same amount of phase fluctuation. In this embodiment, as an example, the phase fluctuation amount in the reception antenna 1-1 and the phase fluctuation amount in the reception antenna 1-2 can be treated as the same value, and the phase fluctuation amount in the reception antenna 1-3 and the reception amount can be received. The case where the phase fluctuation amount in the antenna 1-4 can be treated as the same value will be described.

位相変動量を全受信アンテナで異なる値として扱うと、ユーザ分離部19以降の処理を示した上記の式(5)および(6)は次式(7)のようになる。ここでψmnは、受信アンテナmにおけるユーザnの位相変動量である。本実施の形態で想定しているような、ユーザ数が2,受信アンテナ数が4の場合には、M=4,N=2となる。 When the amount of phase fluctuation is treated as a different value for all receiving antennas, the above equations (5) and (6) showing the processing after the user separation unit 19 are as shown in the following equation (7). Here, ψ mn is the phase fluctuation amount of the user n at the receiving antenna m. When the number of users is 2 and the number of reception antennas is 4 as assumed in this embodiment, M = 4 and N = 2.

Figure 2011097459
Figure 2011097459

式(7)のように計算すると、位相変動量補正に要する演算が、M×N(=4×2)回必要となる。そこで、上述したように、受信アンテナ1−1における位相変動量と受信アンテナ1−2における位相変動量を同じ値,受信アンテナ1−3における位相変動量と受信アンテナ1−4における位相変動量を同じ値として扱うと、式(7)は次式(8)のように変形できる。ただし、ユーザn(n=1,2)の受信アンテナ1−1,1−2における位相変動量をΨ1n,受信アンテナ1−3,1−4における位相変動量をΨ2nとする。 When the calculation is performed as in Expression (7), the calculation required for the phase fluctuation amount correction is required M × N (= 4 × 2) times. Therefore, as described above, the phase fluctuation amount in the receiving antenna 1-1 and the phase fluctuation amount in the receiving antenna 1-2 are the same value, and the phase fluctuation amount in the receiving antenna 1-3 and the phase fluctuation amount in the receiving antenna 1-4 are set as follows. When treated as the same value, equation (7) can be transformed as the following equation (8). However, the phase fluctuation amount in the receiving antennas 1-1 and 1-2 of the user n (n = 1, 2) is ψ 1n , and the phase fluctuation amount in the receiving antennas 1-3 and 1-4 is ψ 2n .

Figure 2011097459
Figure 2011097459

このようにすることで、位相変動補正に要する計算量をM/2×2(=4/2×2)回に低減することができる。   In this way, the amount of calculation required for phase fluctuation correction can be reduced to M / 2 × 2 (= 4/2 × 2) times.

以上の動作について、図3を用いて説明する。なお、実施の形態1と同様の処理については説明を省略する。   The above operation will be described with reference to FIG. Note that description of the same processing as in the first embodiment will be omitted.

図3に示したように、本実施の形態のMIMO受信装置において、ユーザ分離部19は、ユーザ分離処理部19−1および19−2を備える。また、データ位相補正部21−1は、位相補正部21−1−1および21−1−2と、加算部21−1−3とを備え、データ位相補正部21−2は、位相補正部21−2−1および21−2−2と、加算部21−2−3とを備える。   As shown in FIG. 3, in the MIMO receiving apparatus of the present embodiment, user separation section 19 includes user separation processing sections 19-1 and 19-2. The data phase correction unit 21-1 includes phase correction units 21-1-1 and 21-1-2 and an addition unit 21-1-3, and the data phase correction unit 21-2 includes a phase correction unit. 21-2-1 and 21-2-2, and an adder 21-2-3.

図3においては図示を省略している位相変動量推定部11では、受信アンテナ1−1および1−2における位相変動量12−n−1と、受信アンテナ1−3および1−4における位相変動量12−n−2(n=1,2)を求める。求めた位相変動量は、対応する位相補正部へ出力する。なお、求めた位相変動量は既知信号位相補正部13(図1参照)に対しても出力する。   In the phase variation estimation unit 11 (not shown in FIG. 3), the phase variation 12-n-1 in the receiving antennas 1-1 and 1-2, and the phase variation in the receiving antennas 1-3 and 1-4. The quantity 12-n-2 (n = 1, 2) is determined. The obtained phase fluctuation amount is output to the corresponding phase correction unit. The obtained phase fluctuation amount is also output to the known signal phase correction unit 13 (see FIG. 1).

ここで、位相変動量12−n−1,12−n−2の推定方法の一例について説明する。位相変動量12−n−1については、受信アンテナ1−1での受信信号(受信既知信号)から推定した位相変動量と受信アンテナ1−2での受信信号から推定した位相変動量を平均、または一方を選択、または重み付け加算することで、受信アンテナ1−1および1−2で共通の位相変動量12−n−1を求める。同様に、位相変動量12−n−2については、受信アンテナ1−3での受信信号から推定した位相変動量と受信アンテナ1−4での受信信号から推定した位相変動量を平均、または一方を選択、または重み付け加算することで、受信アンテナ1−3および1−4で共通の位相変動量12−n−2を求める。なお、本実施の形態では、受信アンテナ1−1と1−2の位相変動量を同じ値として扱うことができ、また受信アンテナ1−3と1−4の位相変動量を同じ値として扱うことができることが予め分かっているものとして説明を行うが、位相変動量推定部11は、各受信アンテナの位相変動量推定結果を比較して、同じ値として扱うことができるものを特定するようにしてもよい。すなわち、値の近い推定結果は同じ値として扱うことができると判断する。   Here, an example of an estimation method of the phase fluctuation amounts 12-n-1, 12-n-2 will be described. For the phase fluctuation amount 12-n-1, the phase fluctuation amount estimated from the received signal (received known signal) at the receiving antenna 1-1 and the phase fluctuation amount estimated from the received signal at the receiving antenna 1-2 are averaged. Alternatively, a common phase fluctuation amount 12-n-1 is obtained by the receiving antennas 1-1 and 1-2 by selecting one or performing weighted addition. Similarly, for the phase fluctuation amount 12-n-2, the phase fluctuation amount estimated from the reception signal at the reception antenna 1-3 and the phase fluctuation amount estimated from the reception signal at the reception antenna 1-4 are averaged or one of them. Is selected or weighted and added to obtain the common phase fluctuation amount 12-n-2 for the receiving antennas 1-3 and 1-4. In the present embodiment, the phase fluctuation amounts of receiving antennas 1-1 and 1-2 can be treated as the same value, and the phase fluctuation amounts of receiving antennas 1-3 and 1-4 are treated as the same value. However, the phase variation estimation unit 11 compares the phase variation estimation results of the respective receiving antennas to identify those that can be treated as the same value. Also good. That is, it is determined that estimation results having similar values can be handled as the same value.

ユーザ分離部19のユーザ分離処理部19−1および19−2では、データ/既知信号分離部4から入力される受信データ信号6−1〜6−4に対して重み係数作成部17から入力される重み係数18−1−1〜18−2−4を複素乗算することにより、ユーザ分離を行う(上式(8)右辺のwmnm+wm’nm’の部分に相当)。具体的には、図示したように、ユーザ分離処理部19−1が、受信データ信号6−1,6−2と重み係数18−1−1,18−1−2,18−2−1,18−2−2を複素乗算し、ユーザ分離処理部19−2が、受信データ信号6−3,6−4と重み係数18−1−3,18−1−4,18−2−3,18−2−4を複素乗算する。 In the user separation processing units 19-1 and 19-2 of the user separation unit 19, the received data signals 6-1 to 6-4 inputted from the data / known signal separation unit 4 are inputted from the weight coefficient creation unit 17. the weighting factor 18-1-1~18-2-4 by complex multiplication that performs user separation (corresponding to the portion of the equation (8) the right-hand side of the w mn r m + w m'n r m '). Specifically, as shown in the figure, the user separation processing unit 19-1 receives the received data signals 6-1 and 6-2 and the weighting factors 18-1-1, 18-1-2, 18-2-1, and the like. 18-2-2 is subjected to complex multiplication, and the user separation processor 19-2 receives the received data signals 6-3 and 6-4 and the weighting factors 18-1-3, 18-1-4, 18-2-3. Complex multiplication of 18-2-4 is performed.

データ位相補正部21−1,21−2の位相補正部21−1−1,21−1−2,21−2−1,21−2−2では、ユーザ分離部19でユーザ分離されたデータ信号20−1−1,20−1−2,20−2−1,20−2−2に対して、位相変動量推定部11で推定された位相変動量12−1−1,12−1−2,12−2−1,12−2−2を複素乗算する(上式(8)右辺のe-jΨ kn(k=1,2)乗算部分に相当)。具体的には、位相補正部21−1−1が信号20−1−1と位相変動量12−1−1を複素乗算し、その結果得られた信号(位相補正後のデータ信号)26−1−1を加算部21−1−3へ出力する。同様に、位相補正部21−1−2が信号20−1−2と位相変動量12−1−2を複素乗算し、位相補正後のデータ信号26−1−2を加算部21−1−3へ出力する。位相補正部21−2−1が信号20−2−1と位相変動量12−2−1を複素乗算し、位相補正後のデータ信号26−2−1を加算部21−2−3へ出力する。位相補正部21−2−2が信号20−2−2と位相変動量12−2−2を複素乗算し、位相補正後のデータ信号26−2−2を加算部21−2−3へ出力する。 In the phase correction units 21-1-1, 21-1-2, 21-2-1, 21-2-2 of the data phase correction units 21-1 and 21-2, data separated by the user by the user separation unit 19 For the signals 20-1-1, 20-1-2, 20-2-1 and 20-2-2, the phase fluctuation amounts 12-1-1 and 12-1 estimated by the phase fluctuation amount estimation unit 11 -2, 12-2-1 and 12-2-2 are complex-multiplied (corresponding to the e- kn (k = 1,2) multiplication part on the right side of the above equation (8)). Specifically, the phase correction unit 21-1-1 complex-multiplies the signal 20-1-1 and the phase fluctuation amount 12-1-1, and the resulting signal (data signal after phase correction) 26- 1-1 is output to the adder 21-1-3. Similarly, the phase correction unit 21-1-2 performs complex multiplication of the signal 20-1-2 and the phase fluctuation amount 12-1-2, and the phase-corrected data signal 26-1-2 is added to the addition unit 21-1- Output to 3. The phase correction unit 21-2-1 multiplies the signal 20-2-1 and the phase fluctuation amount 12-2-1 and outputs the phase-corrected data signal 26-2-1 to the addition unit 21-2-3. To do. The phase correction unit 21-2-2 multiplies the signal 20-2-2 and the phase fluctuation amount 12-2-2 and outputs the phase-corrected data signal 26-2-2 to the addition unit 21-2-3. To do.

データ位相補正部21−1,21−2の加算部21−1−3,21−2−3では、入力された2系統のデータ信号を加算し、ユーザ毎の復調信号を得る。具体的には、加算部21−1−3は、データ信号26−1−1とデータ信号26−1−2を加算して1番目のユーザ(ユーザ#1)の復調信号22−1を得る。また、加算部21−2−3は、データ信号26−2−1とデータ信号26−2−2を加算して2番目のユーザ(ユーザ#2)の復調信号22−2を得る。   In the addition units 21-1-3 and 21-2-3 of the data phase correction units 21-1 and 21-2, two input data signals are added to obtain a demodulated signal for each user. Specifically, the adding unit 21-1-3 adds the data signal 26-1-1 and the data signal 26-1-2 to obtain the demodulated signal 22-1 of the first user (user # 1). . The adding unit 21-2-3 adds the data signal 26-2-1 and the data signal 26-2-2 to obtain a demodulated signal 22-2 of the second user (user # 2).

なお、本実施の形態では、ユーザ数が2(送信アンテナが2本),受信アンテナが4本の場合について説明したが、さらに多くの受信アンテナを備えた場合にも適用可能である。その場合、3本以上の受信アンテナについて位相変動量を同じとして扱ってもよい。また、たとえば受信アンテナが5本の場合に、距離が近い2本と3本のグループに分ける、2本,2本,1本の3つのグループに分けるなどして、同じグループのアンテナについては位相変動量を同じとして扱うようにすることも可能である。すなわち、位相変動量の差が小さいアンテナ同士(たとえば距離が近いアンテナ同士)が同じグループとなるのであれば、複数のアンテナをどのようにグループ分けするかについては問わない(たとえば、受信アンテナが4本の場合に1本と3本に分けることも可能である)。   In this embodiment, the case where the number of users is 2 (two transmission antennas) and the number of reception antennas is four has been described. However, the present invention can also be applied to a case where more reception antennas are provided. In that case, the phase variation amount may be treated as the same for three or more receiving antennas. Also, for example, when there are five receiving antennas, the antennas of the same group are divided into two groups, two groups, two groups, and one group with two distances. It is also possible to treat the fluctuation amount as the same. That is, if antennas having a small difference in phase fluctuation amount (for example, antennas having a short distance) are in the same group, it does not matter how a plurality of antennas are grouped (for example, four receiving antennas are used). In the case of a book, it can be divided into 1 and 3).

このように、本実施の形態のMIMO受信装置では、複数の受信アンテナのうち、位相変動量が同じ値として扱うことのできる受信アンテナの位相変動量を同じものとして扱って位相補正を行うこととした。これにより、複数の受信アンテナの中に位相変動量が大きく異なるものが含まれる場合であっても、位相変動補正の実行時に発生する誤差が増大するのを防止できるとともに、位相変動補正に要する処理量を従来よりも削減できる。   As described above, in the MIMO receiving apparatus of the present embodiment, among the plurality of receiving antennas, the phase fluctuation amount of the receiving antenna that can be treated as the same value of the phase fluctuation amount is treated as the same value, and the phase correction is performed. did. As a result, even when a plurality of receiving antennas include ones with greatly different phase fluctuation amounts, it is possible to prevent an increase in errors that occur during execution of phase fluctuation correction and to perform processing required for phase fluctuation correction. The amount can be reduced than before.

たとえば、位相変動量を同じ値として扱うことのできる受信アンテナの組をKとすると、各受信アンテナ(受信アンテナの総数をMとする)における受信データ信号に対して位相変動補正処理を行う場合(従来の場合に相当)と比較して、本実施の形態のMIMO受信装置では位相変動補正に要する処理量を「K/M」とすることができ、復調性能を維持しつつ、処理量を削減することができる。   For example, when a set of receiving antennas that can treat the amount of phase variation as the same value is K, the phase variation correction process is performed on the received data signal at each receiving antenna (the total number of receiving antennas is M) ( Compared to the conventional case), the MIMO receiver of this embodiment can reduce the amount of processing required for phase fluctuation correction to “K / M”, while maintaining the demodulation performance. can do.

なお、実施の形態1,2ともにLTEの上りリンクを例として説明を行ったが、これに限る必要はなく、どのようなMIMO受信装置に対しても、本発明は適用可能である。   In the first and second embodiments, the LTE uplink has been described as an example. However, the present invention is not limited to this, and the present invention can be applied to any MIMO receiver.

以上のように、本発明にかかるMIMO受信装置は、無線通信システムに有用であり、特に、復調性能を維持しつつ位置変動補正にかかる処理量を従来よりも削減可能なMIMO受信装置に適している。   As described above, the MIMO receiving apparatus according to the present invention is useful for a radio communication system, and is particularly suitable for a MIMO receiving apparatus that can reduce the amount of processing for position variation correction while maintaining demodulation performance. Yes.

1−1〜1−M 受信アンテナ
3 FFT部
4 データ/既知信号分離部
7 既知信号レプリカ生成部
9 既知信号レプリカ乗算部
11 位相変動量推定部
13 既知信号位相補正部
15 チャネル推定部
17 重み係数作成部
19 ユーザ分離部
19−1,19−2 ユーザ分離処理部
21−1〜21−N データ位相補正部
21−1−1,21−1−2,21−2−1,21−2−2 位相補正部
21−1−3,21−2−3 加算部
1-1 to 1-M reception antenna 3 FFT unit 4 data / known signal separation unit 7 known signal replica generation unit 9 known signal replica multiplication unit 11 phase fluctuation amount estimation unit 13 known signal phase correction unit 15 channel estimation unit 17 weighting factor Creation unit 19 User separation unit 19-1, 19-2 User separation processing unit 21-1 to 21 -N Data phase correction unit 21-1-1, 21-1-2, 21-2, 21-2 2 Phase corrector 21-1-3, 21-2-3 Adder

Claims (3)

MIMO(Multiple Input Multiple Output)受信装置であって、
各受信アンテナで受信したそれぞれの受信信号から、データ信号と既知信号を抽出するデータ/既知信号分離手段と、
前記抽出された既知信号に基づいて、各送信アンテナから送信されたそれぞれの信号の位相変動量を推定する位相変動量推定手段と、
前記位相変動量の推定結果に基づいて、前記既知信号に基づき算出された伝搬路情報の位相を補正する既知信号位相補正手段と、
前記位相が補正された後の伝搬路情報に基づいて、前記抽出されたデータ信号である、各送信アンテナからの送信データ信号が混在した信号、を送信アンテナごとのデータ信号に分離するデータ信号分離手段と、
前記位相変動量の推定結果に基づいて、前記送信アンテナごとのデータ信号それぞれの位相を補正するデータ位相補正手段と、
を備えることを特徴とするMIMO受信装置。
A MIMO (Multiple Input Multiple Output) receiver,
Data / known signal separation means for extracting a data signal and a known signal from each received signal received by each receiving antenna;
Phase fluctuation amount estimation means for estimating the phase fluctuation amount of each signal transmitted from each transmitting antenna based on the extracted known signal;
Based on the estimation result of the phase fluctuation amount, known signal phase correction means for correcting the phase of the propagation path information calculated based on the known signal;
Data signal separation for separating the extracted data signal, which is a mixture of transmission data signals from each transmission antenna, into data signals for each transmission antenna based on propagation path information after the phase is corrected Means,
Data phase correction means for correcting the phase of each data signal for each transmission antenna based on the estimation result of the phase variation amount;
A MIMO receiving apparatus comprising:
前記位相変動量推定手段は、各送信アンテナからの送信信号の位相変動量を受信アンテナごとに推定し、また、位相変動量が同じとみなせる受信アンテナが存在する場合には、同じとみなせる各受信アンテナで受信した信号のそれぞれの位相変動量に基づいて、同じとみなせる各受信アンテナで共通の位相変動量を算出し、
前記データ位相補正手段は、前記位相変動量が同じとみなせる受信アンテナに対応するそれぞれのデータ信号の位相補正をまとめて行う
ことを特徴とする請求項1に記載のMIMO受信装置。
The phase fluctuation amount estimation means estimates the phase fluctuation amount of the transmission signal from each transmission antenna for each reception antenna, and when there are reception antennas that can be regarded as having the same phase fluctuation amount, Based on the amount of phase variation of each signal received by the antenna, calculate the amount of phase variation common to each receiving antenna that can be considered the same,
The MIMO receiving apparatus according to claim 1, wherein the data phase correcting means collectively performs phase correction of respective data signals corresponding to receiving antennas that can be regarded as having the same phase fluctuation amount.
前記データ位相補正手段は、前記位相変動量が同じとみなせる受信アンテナに対応するそれぞれのデータ信号の位相補正をまとめて行った後、同じ送信アンテナから送信されたデータ信号同士を加算することにより、最終的な位相補正後のデータ信号を得る
ことを特徴とする請求項2に記載のMIMO受信装置。
The data phase correction means, after collectively performing the phase correction of each data signal corresponding to the receiving antenna that can be regarded as the same amount of phase variation, by adding the data signals transmitted from the same transmitting antenna, The MIMO signal receiving apparatus according to claim 2, wherein a data signal after final phase correction is obtained.
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