JP4991673B2

JP4991673B2 - Propagation path simulation circuit evaluation method and propagation path simulation circuit evaluation apparatus

Info

Publication number: JP4991673B2
Application number: JP2008275649A
Authority: JP
Inventors: 貴志柳本; 健塩入
Original assignee: Anritsu Corp
Current assignee: Anritsu Corp
Priority date: 2008-10-27
Filing date: 2008-10-27
Publication date: 2012-08-01
Anticipated expiration: 2028-10-27
Also published as: JP2010103924A

Description

本発明は、ＭＩＭＯ（Multiple Input Multiple Output）システムや空間ダイバーシティシステムのように送信側と受信側で複数の異なる電波伝搬路を用いて通信を行う方式に関し、その複数の異なる電波伝搬路を模擬する伝搬路模擬回路の評価を迅速にかつ容易に行うための技術に関する。 The present invention relates to a method of performing communication using a plurality of different radio wave propagation paths on a transmission side and a reception side, such as a MIMO (Multiple Input Multiple Output) system and a spatial diversity system, and simulates the plurality of different radio wave propagation paths. The present invention relates to a technique for quickly and easily evaluating a propagation path simulation circuit.

送信側と受信側との間に介在する複数の異なる電波伝搬路を模擬する伝搬路模擬回路の設計、評価等を行う際に、各伝搬路の遅延特定、振幅特性、雑音特性が所望の特性（伝達関数）になっているかを実際の通信状態に近い状態で確認したい場合がある。 When designing and evaluating a propagation path simulation circuit that simulates multiple different radio wave propagation paths interposed between the transmission side and the reception side, the delay identification, amplitude characteristics, and noise characteristics of each propagation path are the desired characteristics. There is a case where it is desired to check whether the transfer function is in a state close to the actual communication state.

例えば、図８示すように、送信部１１の２つの送信アンテナ１２_１、１２_２から発射された電波を、受信部１３の２つの受信アンテナ１４_１、１４_２で受ける２対２のＭＩＭＯシステムの場合、送信アンテナ１２_１から２つの受信アンテナ１４_１、１４_２に至る２つの伝搬路１５_１，１、１５_１，２と、送信アンテナ１２_２から２つの受信アンテナ１４_１、１４_２に至る２つの伝搬路１５_２，１、１５_２，２の計４つの異なる伝搬路が存在することになる。 For example, as illustrated in FIG. 8, a 2-to-2 MIMO system in which radio waves emitted from two transmission antennas 12 ₁ and 12 ₂ of a transmission unit 11 are received by two reception antennas 14 ₁ and 14 ₂ of a reception unit 13. case, the transmission antenna 12 ₁ of the two receiving antennas ₁₄ 1, 14 ₂ two channel ₁₅ leading to the _1,1, and _{15 1,2,} the transmitting antenna 12 ₂ of the two receiving antennas ₁₄ 1, 14 ₂ leading to 2 There are four different propagation paths, one propagation path 15 _2,1 and 15 _2,2 .

そして、これらの各伝搬路１５_１，１〜１５_２，２の伝達特性をそれぞれｈ_１，１〜ｈ_２，２とし、送信アンテナ１２_１、１２_２から発射された送信信号をＴｘ_１、Ｔｘ_２とすれば、受信アンテナ１４_１、１４_２で受信される受信信号Ｒｘ_１、Ｒｘ_２は、以下のように表すことができる。 Then, the transmission characteristics of these propagation paths 15 _1,1 to 15 _2,2 are set to h _1,1 to h _2,2 , respectively, and the transmission signals emitted from the transmission antennas 12 ₁ and 12 ₂ are Tx ₁ and Tx. if _2, the receiving antenna ₁₄ 1, 14 ₂ receive signal _Rx 1, Rx _2, which is received in, can be expressed as follows.

Ｒｘ_１＝Ｔｘ_１・ｈ_１，１＋Ｔｘ_２・ｈ_２，１
Ｒｘ_２＝Ｔｘ_１・ｈ_１，２＋Ｔｘ_２・ｈ_２，２ Rx ₁ = Tx ₁ · h _1,1 + Tx ₂ · h _2,1
Rx ₂ = Tx ₁ · h _1,2 + Tx ₂ · h _2,2

ここで、送信信号Ｔｘ_１、Ｔｘ_２と受信信号Ｒｘ_１、Ｒｘ_２が既知であるとしても、４つの未知の伝達関数を特定することはできない。 Here, even if the transmission signals Tx ₁ and Tx ₂ and the reception signals Rx ₁ and Rx ₂ are known, four unknown transfer functions cannot be specified.

そこで、上記送信信号Ｔｘ_１、Ｔｘ_２と異なる送信信号Ｔｘ_１′、Ｔｘ_２′を入力したとき、その受信信号Ｒｘ_１′、Ｒｘ_２′は次のようになる。 Therefore, the transmission signal _Tx 1, Tx ₂ and different transmission signal _Tx 1 ', _Tx _2' when entering, the received signal _Rx 1 ', _Rx _2' is as follows.

Ｒｘ_１′＝Ｔｘ_１′・ｈ_１，１＋Ｔｘ_２′・ｈ_２，１
Ｒｘ_２′＝Ｔｘ_１′・ｈ_１，２＋Ｔｘ_２′・ｈ_２，２ Rx ₁ ′ = Tx ₁ ′ · h _1,1 + Tx ₂ ′ · h _2,1
Rx ₂ '= Tx ₁ ' · h _1,2 + Tx ₂ '· h _2,2

つまり、これら４つの連立方程式を解くことで、４つの伝達関数を特定することが可能となる。 That is, it is possible to specify four transfer functions by solving these four simultaneous equations.

なお、上記のような多重伝搬特性を測定する技術は、例えば次の特許文献１に開示されている。 A technique for measuring the multiple propagation characteristics as described above is disclosed in, for example, the following Patent Document 1.

特開平０８−０７９１９１号公報Japanese Patent Application Laid-Open No. 08-079191

しかし、上記のように、例えば２×２の伝搬路回路の４つの伝達関数を求めるために、異なる二組の送信信号を切り替えて、それぞれの受信信号のデータを収集し、上記４つの連立方程式を解く処理は時間を要し、迅速な解析が行えない。 However, as described above, for example, in order to obtain four transfer functions of a 2 × 2 propagation path circuit, two different sets of transmission signals are switched and data of each received signal is collected, and the four simultaneous equations are collected. The process of solving takes time and cannot be quickly analyzed.

また、受信ポート数（前記例では２）に対する伝搬路の総数（前記例では４）の比に相当する回数だけ送信信号の切替処理が必要となり、その比が大きくなるにつれてさらに解析時間がかかってしまう。 In addition, it is necessary to perform transmission signal switching processing a number of times corresponding to the ratio of the total number of propagation paths (4 in the above example) to the number of reception ports (2 in the above example), and further analysis time is required as the ratio increases. End up.

本発明は、この問題を解決し、伝搬路模擬回路の評価を迅速にかつ容易に行うことができる伝搬路模擬回路の評価方法および評価装置を提供することを目的としている。 An object of the present invention is to solve this problem and provide an evaluation method and an evaluation apparatus for a propagation path simulation circuit capable of quickly and easily evaluating a propagation path simulation circuit.

前記目的を達成するために、本発明の請求項１の伝搬路模擬回路評価方法は、
ｎ個（ｎは２以上の整数）の入力ポートとｍ個（ｍは整数）の出力ポートを有し、その入力ポートと出力ポートの間がｎ×ｍ個の伝搬路を模擬した回路で接続されている伝搬路模擬回路の評価を行うための伝搬路模擬回路評価方法であって、
前記伝搬路模擬回路のｎ個の入力ポートに対し、複素数ｅ^ｊωｔで表される送信信号、またはそれと複素共役な送信信号、またはそれらの送信信号に対して周波数が異なる送信信号からなるｎ種類の異なる送信信号を、互いに重複しないようにそれぞれ割り当てて並行して入力する送信信号入力段階（Ｓ１）と、
前記伝搬路模擬回路のｍ個の出力ポートから出力される受信信号に対して、前記ｎ個の入力ポートに並行して与えたｎ種類の送信信号とそれぞれ複素共役なローカル信号を乗算する演算段階（Ｓ３）と、
前記受信信号に対する乗算結果から、前記ローカル信号と複素共役な周波数成分との乗算により前記送信信号と前記ローカル信号の交流分が互いに相殺されて直流に変換された信号成分を前記伝搬路模擬回路の伝搬路の伝達関数として他の交流成分から分離抽出する伝達関数抽出段階（Ｓ４）とを含み、
前記抽出された伝達関数に基づいて前記伝搬路模擬回路の評価を行うことを特徴とする。 In order to achieve the above object, a propagation path simulation circuit evaluation method according to claim 1 of the present invention comprises:
It has n input ports (n is an integer of 2 or more) and m output ports (m is an integer), and the input port and output port are connected by a circuit that simulates n × m propagation paths. A propagation path simulation circuit evaluation method for evaluating a propagation path simulation circuit,
For the n input ports of the propagation path simulation circuit, there are n ^types of transmission signals represented by complex numbers e ^jωt , transmission signals complex with them, or transmission signals having different frequencies from those transmission signals. A transmission signal input step (S1) for assigning different transmission signals so as not to overlap each other and inputting them in parallel;
A calculation step of multiplying reception signals output from the m output ports of the propagation path simulation circuit by n types of transmission signals given in parallel to the n input ports and complex conjugate local signals, respectively. (S3),
From the result of multiplication of the received signal, the signal component converted into DC by the AC component of the transmission signal and the local signal canceling each other by the multiplication of the local signal and the complex conjugate frequency component is converted into the DC of the propagation path simulation circuit. A transfer function extracting step (S4) for separating and extracting from other AC components as a transfer function of the propagation path,
The propagation path simulation circuit is evaluated based on the extracted transfer function.

また、本発明の請求項２の伝搬路模擬回路評価方法は、請求項１記載の伝搬路模擬回路評価方法において、
前記伝搬路模擬回路の入力ポート数ｎと出力ポート数ｍがともに２であって、
前記送信信号入力段階では、
第１入力ポートに対し複素数ｅ^ｊωｔで表される第１送信信号を与え、第２入力ポートに対して第１送信信号と共役な複素数ｅ^−ｊωｔで表される第２送信信号を与え、
前記演算段階では、
第１出力ポートから出力された第１受信信号に対し、前記第１送信信号と共役な複素数ｅ^−ｊωｔで表される第１ローカル信号による乗算処理と、前記第２送信信号と共役な複素数ｅ^ｊωｔで表される第２ローカル信号の乗算処理とを行い、さらに、第２出力ポートから出力された第２受信信号に対して、前記第１ローカル信号による乗算処理と、前記第２ローカル信号による乗算処理とをそれぞれ行い、
前記伝達関数抽出段階では、
前記４種類の乗算処理の結果にそれぞれ含まれる直流の信号成分を前記伝搬路模擬回路の４つの伝搬路の伝達関数として他の交流成分から分離抽出することを特徴とする。 Further, a propagation path simulation circuit evaluation method according to claim 2 of the present invention is the propagation path simulation circuit evaluation method according to claim 1,
The number of input ports n and the number of output ports m of the propagation path simulation circuit are both 2,
In the transmission signal input step,
A first transmission signal represented by a complex number e ^jωt is given to the first input port, and a second transmission signal represented by a complex number e ^−jωt conjugate with the first transmission signal is given to the second input port,
In the calculation stage,
The first received signal output from the first output port is multiplied by a first local signal represented by a complex number e ^−jωt conjugate with the first transmission signal, and a complex number e conjugate with the second transmission signal. The second local signal represented by ^jωt is multiplied, and the second received signal output from the second output port is multiplied by the first local signal and the second local signal. Each with multiplication processing,
In the transfer function extraction step,
A DC signal component included in each of the four types of multiplication results is separated and extracted from other AC components as transfer functions of four propagation paths of the propagation path simulation circuit.

また、本発明の請求項３伝搬路模擬回路評価装置は、
ｎ個（ｎは２以上の整数）の入力ポートとｍ個（ｍは整数）の出力ポートを有し、その入力ポートと出力ポートの間がｎ×ｍ個の伝搬路を模擬した回路で接続されている伝搬路模擬回路の評価を行うための伝搬路模擬回路評価装置であって、
前記伝搬路模擬回路のｎ個の入力ポートに対し、複素数ｅ^ｊωｔで表される送信信号、またはそれと複素共役な送信信号、またはそれらの送信信号に対して周波数を変更した送信信号からなるｎ種類の異なる送信信号を、互いに重複しないようにそれぞれ割り当てて並行して入力する送信信号入力手段（２１）と、
前記伝搬路模擬回路のｍ個の出力ポートから出力される受信信号に対して、前記ｎ個の入力ポートに並行して与えたｎ種類の送信信号とそれぞれ複素共役なローカル信号を乗算する演算手段（２５）と、
前記受信信号に対する乗算結果から、前記ローカル信号と複素共役な周波数成分との乗算により前記送信信号と前記ローカル信号の交流分が互いに相殺されて直流に変換された信号成分を前記伝搬路模擬回路の伝搬路の伝達関数として他の交流成分から分離抽出する伝達関数抽出手段（３０）とを備え、
前記伝達関数抽出手段によって抽出された伝達関数に基づいて前記伝搬路模擬回路の評価を行うことを特徴とする。 Further, a propagation path simulation circuit evaluation apparatus according to claim 3 of the present invention is
It has n input ports (n is an integer of 2 or more) and m output ports (m is an integer), and the input port and output port are connected by a circuit that simulates n × m propagation paths. A propagation path simulation circuit evaluation apparatus for evaluating a propagation path simulation circuit,
For the n input ports of the propagation path simulation circuit, there are n ^types of transmission signals represented by complex numbers e ^jωt , transmission signals complex with them, or transmission signals whose frequencies are changed with respect to those transmission signals. Transmission signal input means (21) for assigning and transmitting different transmission signals in parallel so as not to overlap each other,
Arithmetic means for multiplying received signals output from m output ports of the propagation path simulation circuit by n kinds of transmission signals given in parallel to the n input ports and complex conjugate local signals, respectively. (25) and
From the result of multiplication of the received signal, the signal component converted into DC by the AC component of the transmission signal and the local signal canceling each other by the multiplication of the local signal and the complex conjugate frequency component is converted into the DC of the propagation path simulation circuit. A transfer function extracting means (30) for separating and extracting from other AC components as a transfer function of the propagation path,
The propagation path simulation circuit is evaluated based on the transfer function extracted by the transfer function extracting means.

また、本発明の請求項４の伝搬路模擬回路評価装置は、請求項３記載の伝搬路模擬回路評価装置において、
前記伝搬路模擬回路の入力ポート数ｎと出力ポート数ｍがともに２であって、
前記送信信号入力手段は、
第１入力ポートに対し複素数ｅ^ｊωｔで表される第１送信信号を与え、第２入力ポートに対して第１送信信号と共役な複素数ｅ^−ｊωｔで表される第２送信信号を与えるように構成され、
前記演算手段は、
第１出力ポートから出力された第１受信信号に対し、前記第１送信信号と共役な複素数ｅ^−ｊωｔで表される第１ローカル信号による乗算処理と、前記第２送信信号と共役な複素数ｅ^ｊωｔで表される第２ローカル信号の乗算処理とを行い、さらに、第２出力ポートから出力された第２受信信号に対して、前記第１ローカル信号による乗算処理と、前記第２ローカル信号による乗算処理とをそれぞれ行うように構成され、
前記伝達関数抽出手段は、
前記４種類の乗算処理の結果にそれぞれ含まれる直流の信号成分を前記伝搬路模擬回路の４つの伝搬路の伝達関数として他の交流成分から分離抽出することを特徴とする。 A propagation path simulation circuit evaluation apparatus according to claim 4 of the present invention is the propagation path simulation circuit evaluation apparatus according to claim 3,
The number of input ports n and the number of output ports m of the propagation path simulation circuit are both 2,
The transmission signal input means includes
A first transmission signal represented by a complex number e ^jωt is given to the first input port, and a second transmission signal represented by a complex number e ^−jωt conjugate with the first transmission signal is given to the second input port. Configured,
The computing means is
The first received signal output from the first output port is multiplied by a first local signal represented by a complex number e ^−jωt conjugate with the first transmission signal, and a complex number e conjugate with the second transmission signal. The second local signal represented by ^jωt is multiplied, and the second received signal output from the second output port is multiplied by the first local signal and the second local signal. Each of which performs a multiplication process,
The transfer function extracting means includes
A DC signal component included in each of the four types of multiplication results is separated and extracted from other AC components as transfer functions of four propagation paths of the propagation path simulation circuit.

上記のように本発明では、伝搬路模擬回路のｎ個の入力ポートに対し、複素数ｅ^ｊωｔで表される送信信号、またはそれと複素共役な送信信号、またはそれらの送信信号に対して周波数が異なる送信信号からなるｎ種類の異なる送信信号を、互いに重複しないようにそれぞれ割り当てて並行して入力し、伝搬路模擬回路のｍ個の出力ポートから出力される受信信号に対して、ｎ個の入力ポートに並行して与えたｎ種類の送信信号とそれぞれ複素共役なローカル信号を乗算し、その乗算結果から、ローカル信号と複素共役な周波数成分との乗算により交流分が相殺されて直流に変換された信号成分を伝搬路模擬回路の伝搬路の伝達関数として他の交流成分から分離抽出しているので、送信信号の切替処理が不要となり、伝搬路模擬回路の評価を迅速にかつ容易に行うことができる。 As described above, in the present invention, with ^respect to the n input ports of the propagation path simulation circuit, the frequency differs with respect to the transmission signal represented by the complex number e ^jωt or the complex conjugate transmission signal or those transmission signals. N different types of transmission signals composed of transmission signals are assigned in parallel so as not to overlap with each other and input in parallel, and n inputs are input to reception signals output from m output ports of the propagation path simulation circuit. The n types of transmission signals given in parallel to the ports are multiplied by the complex conjugate local signals, and the multiplication result is multiplied by the local signal and the complex conjugate frequency component to cancel the AC component and convert it to DC. Signal components are separated and extracted from other AC components as the transfer function of the propagation path of the propagation path simulation circuit, so transmission signal switching processing becomes unnecessary, and the propagation path simulation circuit is evaluated. It can and easily performed that the speed.

以下、図面に基づいて本発明の実施の形態を説明する。
図１は、前記したように２×２のＭＩＭＯシステムで、２つの入力ポートと２つの出力ポートを有し、その入力ポートと出力ポートの間が４個の伝搬路を模擬した回路で接続されている伝搬路模擬回路の４つの伝達関数ｈ_１，１〜ｈ_２，２を求めて、伝搬路模擬回路の評価を行う手順を示すフローチャートである。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a 2 × 2 MIMO system as described above, which has two input ports and two output ports, and the input port and the output port are connected by a circuit that simulates four propagation paths. 4 is a flowchart showing a procedure for obtaining four transfer functions h _{1,1 to} h _2,2 of a propagation path simulation circuit and evaluating the propagation path simulation circuit.

始めに、伝搬路模擬回路の２つの入力ポートに、以下のように、互いに共役な複素数で示される第１送信信号Ｔｘ_１と第２送信信号Ｔｘ_２とを入力する（Ｓ１）。 First, the first transmission signal Tx ₁ and the second transmission signal Tx ₂ represented by complex numbers that are conjugate to each other are input to the two input ports of the propagation path simulation circuit as follows (S1).

Ｔｘ_１＝ｅ^ｊωｔ＝cos ωｔ＋ｊ・sin ωｔ ……（１）
Ｔｘ_２＝ｅ^−ｊωｔ＝cos ωｔ−ｊ・sin ωｔ ……（２） Tx ₁ = e ^jωt = cos ωt + j · sin ωt (1)
Tx ₂ = e ^−jωt = cos ωt−j · sin ωt (2)

このとき、伝搬路模擬回路の２つの出力ポートから出力される第１受信信号Ｒｘ_１と第２受信信号Ｒｘ_２は、以下の通りとなる。 At this time, the first reception signal Rx ₁ and the second reception signal Rx ₂ output from the two output ports of the propagation path simulation circuit are as follows.

Ｒｘ_１＝Ｔｘ_１・ｈ_１，１＋Ｔｘ_２・ｈ_２，１
＝ｅ^ｊωｔ・ｈ_１，１＋ｅ^−ｊωｔ・ｈ_２，１ ……（３）
Ｒｘ_２＝Ｔｘ_１・ｈ_１，２＋Ｔｘ_２・ｈ_２，２
＝ｅ^ｊωｔ・ｈ_１，２＋ｅ^−ｊωｔ・ｈ_２，２ ……（４） Rx ₁ = Tx ₁ · h _1,1 + Tx ₂ · h _2,1
= E ^jωt · h _1,1 + e ^−jωt · h _2,1 (3)
Rx ₂ = Tx ₁ · h _1,2 + Tx ₂ · h _2,2
= E ^jωt · h _1,2 + e ^−jωt · h _2,2 (4)

この受信信号は、例えば所定のサンプリング周期でサンプリングされてデジタルの信号列に変換されてメモリなどの記憶装置に収集される（Ｓ２）。ただし、以下の説明では処理が理解しやすいように、受信信号データも時間的に連続しているものとして説明する。 The received signal is sampled, for example, at a predetermined sampling period, converted into a digital signal sequence, and collected in a storage device such as a memory (S2). However, in the following description, it is assumed that the received signal data is continuous in time so that the processing is easy to understand.

そして、得られた２組の受信信号データに対して、前記送信信号と共役な複素数のローカル信号による乗算処理がなされる（Ｓ３）。 Then, the two sets of received signal data obtained are multiplied by a complex local signal conjugate with the transmission signal (S3).

ただし、この例では２種類の送信信号同士が互いに複素共役であるから、どちらの送信信号と等しいローカル信号を用いてもよい。 However, in this example, since two types of transmission signals are complex conjugates with each other, a local signal equal to either transmission signal may be used.

例えば、受信信号Ｒｘ_１に対し、複素数ｅ^−ｊωｔで表される第１ローカル信号Ｌ_１を乗算すると、以下の結果Ｕ_１が得られる。 For example, when the received signal Rx ₁ is multiplied by the first local signal L ₁ represented by the complex number e ^−jωt , the following result U ₁ is obtained.

Ｕ_１＝Ｌ_１・Ｒｘ_１＝ｅ^−ｊωｔ・Ｒｘ_１
＝ｅ^ｊωｔ・ｅ^−ｊωｔ・ｈ_１，１＋ｅ^−ｊωｔ・ｅ^−ｊωｔ・ｈ_２，１
＝ｅ^ｊ０・ｈ_１，１＋ｅ^{−ｊ２ωｔ}・ｈ_２，１
＝ｈ_１，１＋ｅ^{−ｊ２ωｔ}・ｈ_２，１ ……（５） U ₁ = L ₁ · Rx ₁ = e ^−jωt · Rx ₁
= E ^jωt · e ^−jωt · h _1,1 + e ^−jωt · e ^−jωt · h _2,1
= E ^j0 · h _1,1 + e ^−j2ωt · h _2,1
= H _1,1 + e ^−j2ωt · h _2,1 (5)

また、受信信号Ｒｘ_１に対し、複素数ｅ^ｊωｔで表される第２ローカル信号Ｌ_２を乗算すると、以下の結果Ｕ_２が得られる。 Further, when the received signal Rx ₁ is multiplied by the second local signal L ₂ represented by the complex number e ^jωt , the following result U ₂ is obtained.

Ｕ_２＝Ｌ_２・Ｒｘ_１＝ｅ^ｊωｔ・Ｒｘ_１
＝ｅ^ｊωｔ・ｅ^ｊωｔ・ｈ_１，１＋ｅ^ｊωｔ・ｅ^−ｊωｔ・ｈ_２，１
＝ｅ^ｊ２ωｔ・ｈ_１，１＋ｅ^ｊ０・ｈ_２，１
＝ｅ^ｊ２ωｔ・ｈ_１，１＋ｈ_２，１ ……（６） U ₂ = L ₂ · Rx ₁ = e ^jωt · Rx ₁
= E ^jωt · e ^jωt · h _1,1 + e ^jωt · e ^−jωt · h _2,1
= E ^j2ωt · h _1,1 + e ^j0 · h _2,1
= E ^j2ωt · h _1,1 + h _2,1 (6)

また、受信信号Ｒｘ_２に対し、複素数ｅ^−ｊωｔで表される第１ローカル信号Ｌ_１を乗算すると、以下の結果Ｕ_３が得られる。 Further, when the received signal Rx ₂ is multiplied by the first local signal L ₁ represented by the complex number e ^−jωt , the following result U ₃ is obtained.

Ｕ_３＝Ｌ_１・Ｒｘ_２＝ｅ^−ｊωｔ・Ｒｘ_２
＝ｅ^ｊωｔ・ｅ^−ｊωｔ・ｈ_１，２＋ｅ^−ｊωｔ・ｅ^−ｊωｔ・ｈ_２，２
＝ｅ^ｊ０・ｈ_１，２＋ｅ^{−ｊ２ωｔ}・ｈ_２，２
＝ｈ_１，２＋ｅ^{−ｊ２ωｔ}・ｈ_２，２ ……（７） U ₃ = L ₁ · Rx ₂ = e ^−jωt · Rx ₂
= E ^jωt · e ^−jωt · h _1,2 + e ^−jωt · e ^−jωt · h _2,2
= E ^j0 · h _1,2 + e ^−j2ωt · h _2,2
= H _1,2 + e ^−j2ωt · h _2,2 (7)

さらに、受信信号Ｒｘ_２に対し、複素数ｅ^ｊωｔで表される第２ローカル信号Ｌ_２を乗算すると、以下の結果Ｕ_４が得られる。 Further, when the received signal Rx ₂ is multiplied by the second local signal L ₂ represented by the complex number e ^jωt , the following result U ₄ is obtained.

Ｕ_４＝Ｌ_２・Ｒｘ_２＝ｅ^ｊωｔ・Ｒｘ_２
＝ｅ^ｊωｔ・ｅ^ｊωｔ・ｈ_１，２＋ｅ^ｊωｔ・ｅ^−ｊωｔ・ｈ_２，２
＝ｅ^ｊ２ωｔ・ｈ_１，２＋ｅ^ｊ０・ｈ_２，２
＝ｅ^ｊ２ωｔ・ｈ_１，２＋ｈ_２，２ ……（８） U ₄ = L ₂ · Rx ₂ = e ^jωt · Rx ₂
= E ^jωt · e ^jωt · h _1,2 + e ^jωt · e ^−jωt · h _2,2
= E ^j2ωt · h _1,2 + e ^j0 · h _2,2
= E ^j2ωt · h _1,2 + h _2,2 (8)

上式（５）〜（８）の乗算結果Ｕ_１〜Ｕ_４は、いずれも共役な複素数の乗算により送信信号とローカル信号の交流分が互いに相殺されて直流帯に変換された伝達関数の信号成分（包絡線成分）と、ローカル信号の２倍の周波数の高周波成分との和になっている。 The multiplication results U _{1 to} U ₄ of the above formulas (5) to (8) are signals of transfer functions that are converted to the DC band by canceling the AC components of the transmission signal and the local signal with each other by multiplication of conjugate complex numbers. It is the sum of a component (envelope component) and a high frequency component having a frequency twice that of the local signal.

したがって、これらの乗算結果Ｕ_１〜Ｕ_４から、例えばローパスフィルタを用いて直流分を交流分から分離抽出する（Ｓ４）ことにより、各伝達関数ｈ_１，１〜ｈ_２，２を求めることができる。 Therefore, each transfer function h _{1,1 to} h _2,2 can be obtained by separating and extracting the direct current component from the alternating current component using, for example, a low-pass filter from these multiplication results U _{1 to} U ₄ (S4). .

このようにして伝達関数が求まると、伝搬路模擬回路の評価が可能となる（Ｓ５）。
この評価例としては、各伝達関数の時間波形に対する統計処理、即ち、ＰＤＦ（振幅確率密度）やＬＣＲ（レベル交差比）等を求めて、所望特性になっているか否かを調べる。 When the transfer function is obtained in this way, the propagation path simulation circuit can be evaluated (S5).
As an evaluation example, statistical processing on the time waveform of each transfer function, that is, PDF (amplitude probability density), LCR (level crossing ratio), and the like are obtained to check whether or not the desired characteristics are obtained.

また、ＭＩＭＯのチャネル情報（相関行列）Ｒ_MIMOを次の演算によって求めることができる。 Also, MIMO channel information (correlation matrix) R _MIMO can be obtained by the following calculation.

このチャネル情報Ｒ_MIMOは、各伝搬路の特性の相関性を示すものであり、理想的には各伝搬路が独立していて相関が小さいことが望ましい。 This channel information R _MIMO indicates the correlation of the characteristics of each propagation path. Ideally, each propagation path is independent and desirably has a small correlation.

図２は、上記評価方法を用いて２×２のＭＩＭＯ方式の伝搬路模擬回路（ＭＩＭＯシミュレータ）１を評価するための伝搬路模擬回路評価装置２０の構成例を示している。 FIG. 2 shows a configuration example of a propagation path simulation circuit evaluation apparatus 20 for evaluating a 2 × 2 MIMO propagation path simulation circuit (MIMO simulator) 1 using the above evaluation method.

この伝搬路模擬回路１の入力ポート２の数ｎと出力ポート３の数ｍがともに２であって、送信信号入力手段２１は、伝搬路模擬回路１の第１入力ポート２ａに対して、前記式（１）、（２）で示したように、前記複素数ｅ^ｊωｔで表される第１送信信号Ｔｘ_１を与え、第２入力ポート２ｂに対して第１送信信号Ｔｘ_１と共役な複素数ｅ^−ｊωｔで表される第２送信信号Ｔｘ_２を与える。 The number n of the input ports 2 and the number m of the output ports 3 of the propagation path simulation circuit 1 are both 2, and the transmission signal input means 21 is connected to the first input port 2a of the propagation path simulation circuit 1 with respect to the first input port 2a. equation (1), as indicated by (2), the complex number ^e providing a first transmission signal Tx ₁ represented by ^{j? t,} the first transmission signal Tx ₁ conjugate complex number e to the second input port 2b ^A second transmission signal Tx ₂ represented by ^−jωt is given.

このとき、伝搬路模擬回路１の２つの出力ポート３ａ、３ｂからそれぞれ出力される第１受信信号Ｒｘ_１と第２受信信号Ｒｘ_２は前記式（３）、（４）で表されるが、この受信信号は、２チャンネル型のＡ／Ｄ変換器２２により、所定のサンプリング周波数（送信信号の周波数の２倍以上の周波数）でサンプリングされてデジタルの信号列に変換されて受信データメモリ２３に一定時間分記憶収集される。ただし、以下の説明では処理が理解しやすいように、受信信号データも時間的に連続しているものとして説明する。 At this time, the first received signal Rx ₁ and the second received signal Rx ₂ respectively output from the two output ports 3a and 3b of the propagation path simulation circuit 1 are expressed by the equations (3) and (4). This received signal is sampled by a two-channel A / D converter 22 at a predetermined sampling frequency (a frequency that is at least twice the frequency of the transmission signal), converted into a digital signal sequence, and stored in the received data memory 23. Memory is collected for a certain time. However, in the following description, it is assumed that the received signal data is continuous in time so that the processing is easy to understand.

演算手段２５は、受信データメモリ２３に一定時間分のデータが記憶されると、これを読み出し、出力ポート３ａ、３ｂから出力された各受信信号に対して、それぞれ送信に用いた信号と複素共役なローカル信号による乗算処理を行う。 When the data for a predetermined time is stored in the reception data memory 23, the arithmetic means 25 reads this data, and for each reception signal output from the output ports 3a and 3b, the signal used for transmission and the complex conjugate are respectively received. Multiplication processing using a local signal is performed.

この演算手段２５の構成は任意であり、上記のように一定時間分の受信データを記憶してから乗算処理を行う場合には、図３のように、一つの乗算器２６と２つのローカル信号発生器２７、２８とローカル信号を切り替えるスイッチ２９で構成することができる。 The configuration of the calculation means 25 is arbitrary, and when the multiplication processing is performed after storing the received data for a certain time as described above, one multiplier 26 and two local signals are used as shown in FIG. It can be composed of generators 27 and 28 and a switch 29 for switching the local signal.

この場合、一方の受信信号Ｒｘ_１のデータ列を読み出して乗算器２６に与えるとともに一方のローカル信号Ｌ_１を選択して乗算器２６に与えて、その乗算処理が終了したら、一方の受信信号Ｒｘ_１のデータ列を再度読み出して乗算器２６に与えるとともに他方のローカル信号Ｌ_２を選択して乗算器２６に与える。これらの処理で前記した式（５）、（６）の演算結果Ｕ_１、Ｕ_２が得られる。 In this case, given to the multiplier 26 by selecting one of the local signal L ₁ together give to the multiplier 26 reads the data sequence of one of the received signal Rx _1, When the multiplication process is completed, one of the reception signal Rx providing with given to the multiplier 26 reads again the data string of ₁ to the multiplier 26 to select the other local signal L _2. With these processes, the calculation results U ₁ and U ₂ of the above-described equations (5) and (6) are obtained.

また、さらに、他方の受信信号Ｒｘ_２のデータ列を読み出して乗算器２６に与えるとともに一方のローカル信号Ｌ_１を選択して乗算器２６に与えて、その乗算処理が終了したら、他方の受信信号Ｒｘ_２のデータ列を再度読み出して乗算器２６に与えるとともに他方のローカル信号Ｌ_２を選択して乗算器２６に与える。これらの処理で前記した式（７）、（８）の演算結果Ｕ_３、Ｕ_４が得られる。 Also, further, it is given to select one of the local signal L ₁ multiplier 26 together provide the multiplier 26 reads the data row of the other received signals Rx _2, When the multiplication process is completed, the other received signal together gives the multiplier 26 reads out the data sequence rx ₂ again given to the multiplier 26 to select the other local signal L _2. By these processes, the calculation results U ₃ and U _{4 of} the expressions (7) and (8) described above are obtained.

また、図４のように、２組の乗算器２６ａ、２６ｂと２つのローカル信号発生器２７、２８とで構成することもできる。この場合には、一方の受信信号Ｒｘ_１のデータ列を読み出して乗算器２６ａ、２６ｂに与えるとともに一方のローカル信号Ｌ_１を乗算器２６ａに与え、他方のローカル信号Ｌ_２を乗算器２６ｂに与えることで各乗算結果Ｕ_１、Ｕ_２を得た後に、受信信号Ｒｘ_１に代わって受信信号Ｒｘ_２のデータ列を読み出して同様の乗算処理を行うことでその乗算結果Ｕ_３、Ｕ_４を得る。 Further, as shown in FIG. 4, it can be constituted by two sets of multipliers 26 a and 26 b and two local signal generators 27 and 28. In this case, one of the received signal Rx ₁ of the data sequence read out multiplier 26a, one of the local signal _{L 1} together give 26b provided to the multiplier 26a, giving the other local signal _{L 2} to the multiplier 26b Thus, after obtaining the multiplication results U ₁ and U ₂ , the data sequence of the reception signal Rx ₂ is read in place of the reception signal Rx ₁ and the same multiplication processing is performed to obtain the multiplication results U ₃ and U ₄ . .

さらに２組の受信データの読出しを並行して行える構成であれば、図５のように、４組の乗算器２６ａ〜２６ｄと２つのローカル信号発生器２７、２８で構成することもできる。この場合には、受信信号Ｒｘ_１のデータ列を乗算器２６ａ、２６ｂに与えるとともに一方のローカル信号Ｌ_１を乗算器２６ａに与え、他方のローカル信号Ｌ_２を乗算器２６ｂに与えて、さらにこれと並行して受信信号Ｒｘ_２のデータ列を乗算器２６ｃ、２６ｄに与えるとともに一方のローカル信号Ｌ_１を乗算器２６ｃに与え、他方のローカル信号Ｌ_２を乗算器２６ｄに与えることで、前記乗算結果Ｕ_１〜Ｕ_４を並行して求めることができる。 Furthermore, if two sets of received data can be read out in parallel, it can be configured with four sets of multipliers 26a to 26d and two local signal generators 27 and 28 as shown in FIG. In this case, the data string of the received signal Rx ₁ is supplied to the multipliers 26a and 26b, one local signal L ₁ is supplied to the multiplier 26a, and the other local signal L ₂ is supplied to the multiplier 26b. parallel data sequence of the received signal Rx ₂ in multiplier 26c and, given the multiplier 26c to one of the local signal _{L 1} together give 26 d, by giving the other local signal _{L 2} to the multiplier 26 d, the multiplication The results U _{1 to} U ₄ can be obtained in parallel.

このようにして得られた乗算結果Ｕ_１〜Ｕ_４は、伝達関数抽出手段３０に入力され、各乗算結果Ｕ_１〜Ｕ_４にそれぞれ含まれる直流成分が、伝搬路模擬回路１の４つの伝搬路の伝達関数ｈ_１，１〜ｈ_２，２として他の交流成分からそれぞれ分離抽出される。 The multiplication results U _{1 to} U ₄ obtained in this way are input to the transfer function extraction means 30, and the direct current components included in the multiplication results U _{1 to} U ₄ are the _four propagations of the propagation path simulation circuit 1. The transfer functions h _{1,1 to} h _2,2 of the road are separated and extracted from other AC components, respectively.

ここで、伝達関数抽出手段３０としては、乗算結果Ｕ_１〜Ｕ_４にそれぞれ含まれる直流分とローカル信号の２倍の周波数成分との間にカットオフ周波数をもつローパスフィルタで構成することができ、図３〜図５にそれぞれ示しているように、演算部２５の乗算器にそれぞれ対応してこのローパスフィルタ３０ａ〜３０ｄを設けることで実現できる。 Here, the transfer function extracting means 30 can be constituted by a low-pass filter having a cut-off frequency between a direct current component included in each of the multiplication results U _{1 to} U ₄ and a frequency component twice the local signal. As shown in FIGS. 3 to 5, it can be realized by providing the low-pass filters 30 a to 30 d corresponding to the multipliers of the arithmetic unit 25, respectively.

このようにして得られた伝達関数は、評価演算部３５に入力され、前記したようなＰＤＦ（振幅確率密度）やＬＣＲ（レベル交差比）等の統計量、あるいは前記ＭＩＭＯのチャネル情報（相関行列）Ｒ_MIMOが求められ、それらに基づく評価が可能となる。 The transfer function obtained in this way is input to the evaluation calculation unit 35, and statistics such as PDF (amplitude probability density) and LCR (level crossing ratio) as described above, or the MIMO channel information (correlation matrix). ) R _MIMO is required, and evaluation based on them is possible.

前記実施形態では２つの入力ポートに与える送信信号同士が互いに複素共役であったが、これは本発明を限定するものではなく、異なる周波数の複素数信号であってもよい。 In the embodiment, the transmission signals applied to the two input ports are complex conjugates with each other. However, this does not limit the present invention, and complex signals having different frequencies may be used.

例えば、異なる角周波数ω＝２πｆ、ω′＝２πｆ′に対して、第１送信信号Ｔｘ_１をｅ^ｊωｔ（またはｅ^−ｊωｔ）、第２送信信号Ｔｘ_２をｅ^ｊω′ｔ（またはｅ^{−ｊω′ｔ}）とすることも可能である。ただし、この場合、異なる角周波数としては、前記した乗算処理で得られる直流分をフィルタで抽出する際に急峻なカットオフ特性が要求されることが無いように、それぞれが０（直流）に近くなく（高周波）、その差の絶対値｜ω−ω′｜も０（直流）に近くないことが要求される。 For example, for different angular frequencies ω = 2πf and ω ′ = 2πf ′, the first transmission signal Tx ₁ is e ^jωt (or e ^−jωt ), and the second transmission signal Tx ₂ is e ^jω′t (or e ^{−jω 'T} ) can also be used. However, in this case, each of the different angular frequencies is close to 0 (direct current) so that a steep cut-off characteristic is not required when the direct current obtained by the multiplication process is extracted by a filter. The absolute value of the difference | ω−ω ′ | is not close to 0 (direct current).

この条件を満たす例としては、ω＝２ω′（ｆ＝２ｆ′）、またはその逆の２ω＝ω′（２ｆ＝ｆ′）の関係がある。 As an example satisfying this condition, there is a relationship of ω = 2ω ′ (f = 2f ′) or vice versa 2ω = ω ′ (2f = f ′).

例えば、第１送信信号Ｔｘ_１＝ｅ^ｊωｔ、第２送信信号Ｔｘ_２＝ｅ^ｊω′ｔ、ω＝２ω′の例で説明すると、伝搬路模擬回路１の２つの出力ポート３ａ、３ｂから出力される第１受信信号Ｒｘ_１と第２受信信号Ｒｘ_２は、以下の通りとなる。 For example, in the example of the first transmission signal Tx ₁ = e ^jωt , the second transmission signal Tx ₂ = e ^jω′t , and ω = 2ω ′, the signals are output from the two output ports 3 a and 3 b of the propagation path simulation circuit 1. The first received signal Rx ₁ and the second received signal Rx ₂ are as follows.

Ｒｘ_１＝Ｔｘ_１・ｈ_１，１＋Ｔｘ_２・ｈ_２，１
＝ｅ^ｊωｔ・ｈ_１，１＋ｅ^ｊω′ｔ・ｈ_２，１ ……（３′）
Ｒｘ_２＝Ｔｘ_１・ｈ_１，２＋Ｔｘ_２・ｈ_２，２
＝ｅ^ｊωｔ・ｈ_１，２＋ｅ^ｊω′ｔ・ｈ_２，２ ……（４′） Rx ₁ = Tx ₁ · h _1,1 + Tx ₂ · h _2,1
= E ^jωt · h _1,1 + e ^jω′t · h _2,1 (3 ′)
Rx ₂ = Tx ₁ · h _1,2 + Tx ₂ · h _2,2
= E ^jωt · h _1,2 + e ^jω′t · h _2,2 (4 ′)

そして、受信信号Ｒｘ_１に対し、第１送信信号Ｔｘ_１と共役な複素数ｅ^−ｊωｔで表される第１ローカル信号Ｌ_１を乗算すると、以下の結果Ｕ_１が得られる。 Then, when the reception signal Rx ₁ is multiplied by the first local signal L ₁ represented by the complex number e ^−jωt conjugate with the first transmission signal Tx ₁ , the following result U ₁ is obtained.

Ｕ_１＝Ｌ_１・Ｒｘ_１＝ｅ^−ｊωｔ・Ｒｘ_１
＝ｅ^−ｊωｔ・ｅ^ｊωｔ・ｈ_１，１＋ｅ^−ｊωｔ・ｅ^ｊω′ｔ・ｈ_２，１
＝ｅ^ｊ０・ｈ_１，１＋ｅ^{−ｊ（ω−ω′）ｔ}・ｈ_２，１
＝ｈ_１，１＋ｅ^{−ｊω′ｔ}・ｈ_２，１ ……（５′） U ₁ = L ₁ · Rx ₁ = e ^−jωt · Rx ₁
= E ^−jωt · e ^jωt · h _1,1 + e ^−jωt · e ^jω′t · h _2,1
= E ^j0 · h _1,1 + e ^{−j (ω−ω ′) t} · h _2,1
= H _1,1 + e ^−jω′t · h _2,1 (5 ′)

また、受信信号Ｒｘ_１に対し、第２送信信号Ｔｘ_２と共役な複素数ｅ^{−ｊω′ｔ}で表される第２ローカル信号Ｌ_２を乗算すると、以下の結果Ｕ_２が得られる。 Further, when the received signal Rx ₁ is multiplied by the second local signal L ₂ represented by the complex number e ^−jω′t conjugate with the second transmission signal Tx ₂ , the following result U ₂ is obtained.

Ｕ_２＝Ｌ_２・Ｒｘ_１＝ｅ^{−ｊω′ｔ}・Ｒｘ_１
＝ｅ^ｊωｔ・ｅ^{−ｊω′ｔ}・ｈ_１，１＋ｅ^ｊω′ｔ・ｅ^{−ｊω′ｔ}・ｈ_２，１
＝ｅ^{ｊ（ω−ω′）ｔ}・ｈ_１，１＋ｅ^ｊ０・ｈ_２，１
＝ｅ^ｊω′ｔ・ｈ_１，１＋ｈ_２，１ ……（６′） U ₂ = L ₂ · Rx ₁ = e ^−jω′t · Rx ₁
= E ^jωt · e ^−jω′t · h _1,1 + e ^jω′t · e ^−jω′t · h _2,1
= E ^{j (ω−ω ′) t} · h _1,1 + e ^j0 · h _2,1
= E ^jω′t · h _1,1 + h _2,1 (6 ′)

また、受信信号Ｒｘ_２に対し、第１ローカル信号Ｌ_１を乗算すると、以下の結果Ｕ_３が得られる。 Further, when the received signal Rx ₂ is multiplied by the first local signal L ₁ , the following result U ₃ is obtained.

Ｕ_３＝Ｌ_１・Ｒｘ_２＝ｅ^−ｊωｔ・Ｒｘ_２
＝ｅ^−ｊωｔ・ｅ^ｊωｔ・ｈ_１，２＋ｅ^−ｊωｔ・ｅ^ｊω′ｔ・ｈ_２，２
＝ｅ^ｊ０・ｈ_１，２＋ｅ^{−ｊ（ω−ω′）ｔ}・ｈ_２，２
＝ｈ_１，２＋ｅ^{−ｊω′ｔ}・ｈ_２，２ ……（７′） U ₃ = L ₁ · Rx ₂ = e ^−jωt · Rx ₂
= E ^−jωt · e ^jωt · h _1,2 + e ^−jωt · e ^jω′t · h _2,2
= E ^j0 · h _1,2 + e ^{−j (ω−ω ′) t} · h _2,2
= H _1,2 + e ^−jω′t · h _2,2 (7 ′)

さらに、受信信号Ｒｘ_２に対し、第２ローカル信号Ｌ_２を乗算すると、以下の結果Ｕ_４が得られる。 Further, with respect to the received signal Rx _2, when multiplied by the second local signal _{L 2,} the result _{U 4} is obtained.

Ｕ_４＝Ｌ_２・Ｒｘ_２＝ｅ^{−ｊω′ｔ}・Ｒｘ_２
＝ｅ^ｊωｔ・ｅ^{−ｊω′ｔ}・ｈ_１，２＋ｅ^ｊω′ｔ・ｅ^{−ｊω′ｔ}・ｈ_２，２
＝ｅ^{ｊ（ω−ω′）ｔ}・ｈ_１，２＋ｅ^ｊ０・ｈ_２，２
＝ｅ^ｊω′ｔ・ｈ_１，２＋ｈ_２，２ ……（８′） U ₄ = L ₂ · Rx ₂ = e ^−jω′t · Rx ₂
= E ^jωt · e ^−jω′t · h _1,2 + e ^jω′t · e ^−jω′t · h _2,2
= E ^{j (ω−ω ′) t} · h _1,2 + e ^j0 · h _2,2
= E ^jω′t · h _1,2 + h _2,2 (8 ′)

上式（５′）〜（８′）の乗算結果Ｕ_１〜Ｕ_４は、いずれも共役な複素数の乗算により直流帯に変換された伝達関数の信号成分（包絡線成分）と、第２ローカル信号Ｌ_２の周波数（ω′）の高周波成分との和になっており、それらの乗算結果から直流帯を分離抽出することで、前記同様に４つの伝達関数ｈ_１，１〜ｈ_２，２を求めることができる。ただし、この場合、伝達関数ｈ_１，１〜ｈ_２，２の抽出に要求されるフィルタのカットオフ周波数は第２ローカル信号Ｌ_２の周波数（ω′）より低い位置に設定する必要がある。 The multiplication results U _{1 to} U ₄ of the above formulas (5 ′) to (8 ′) are the signal component (envelope component) of the transfer function converted into the DC band by the multiplication of conjugate complex numbers and the second local This is the sum of the high frequency component of the frequency (ω ′) of the signal L ₂ , and the four transfer functions h _{1,1 to} h _2,2 are similarly extracted by separating and extracting the DC band from the multiplication result. Can be requested. However, in this case, the cut-off frequency of the filter required for extracting the transfer functions h _{1,1 to} h _2,2 needs to be set at a position lower than the frequency (ω ′) of the second local signal L ₂ .

また、前記実施形態では、２×２の伝搬路模擬回路１の４つの伝達関数を求める場合について説明したが、図６のように２×１の伝搬路模擬回路１の場合には、出力ポート３ａが一つで受信信号Ｒｘ_１は、前記式（３）あるいは式（３′）で表され、これに前記同様に送信信号と複素共役なローカル信号Ｌ_１、Ｌ_２を乗じ、その乗算結果Ｕ_１、Ｕ_２から直流分をそれぞれ抽出すれば、２つの伝達関数ｈ_１，１、ｈ_２，１を求めることができる。 In the above embodiment, the case where four transfer functions of the 2 × 2 propagation path simulation circuit 1 are obtained has been described. However, in the case of the 2 × 1 propagation path simulation circuit 1 as shown in FIG. The reception signal Rx ₁ with one 3a is expressed by the equation (3) or (3 ′), and is multiplied by the local signals L ₁ and L ₂ complex to the transmission signal and complex as described above, and the multiplication result If the direct current component is extracted from U ₁ and U ₂ , two transfer functions h _1,1 and h _2,1 can be obtained.

また、入力ポート数ｎが３つ以上の場合には、上記送信信号として互いに複素共役な信号と、それと周波数が異なる信号を含めて、ｎ種類の異なる送信信号を用いる。 When the number of input ports n is 3 or more, n different types of transmission signals are used, including a complex conjugate signal and a signal having a frequency different from that of the transmission signal.

例えば図７のように、入力ポート数ｎが４の場合には、次の４つの送信信号を各入力ポート２ａ〜２ｄに並行して入力する。なお、前記したように、周波数関係としてω＝２ω′が望ましい。 For example, as shown in FIG. 7, when the number of input ports n is 4, the following four transmission signals are input in parallel to the input ports 2a to 2d. As described above, ω = 2ω ′ is desirable as the frequency relationship.

Ｔｘ_１＝ｅ^ｊωｔ
Ｔｘ_２＝ｅ^−ｊωｔ
Ｔｘ_３＝ｅ^ｊω′ｔ
Ｔｘ_４＝ｅ^{−ｊω′ｔ} Tx ₁ = e ^jωt
^Tx ₂ = ^e -jωt
Tx ₃ = e ^jω′t
Tx ₄ = e ^−jω′t

ここで図７のように、出力ポート数ｍも４とすれば、入ポート２ａ〜２ｄと出力ポート３ａ〜３ｄの間には、４×４＝１６の伝搬路が存在し、その数分の伝達関数ｈ_１，１〜ｈ_４，４を求めることになる。 As shown in FIG. 7, if the number of output ports m is also 4, there are 4 × 4 = 16 propagation paths between the input ports 2a to 2d and the output ports 3a to 3d. The transfer functions h _{1,1 to} h _4,4 are obtained.

このとき、各出力ポート３ａ〜３ｄから出力される受信信号Ｒｘ_１〜Ｒｘ_４は以下のように表される。 At this time, the reception signals Rx _{1 to} Rx ₄ output from the output ports 3a to 3d are expressed as follows.

Ｒｘ_１＝Ｔｘ_１・ｈ_１，１＋Ｔｘ_２・ｈ_２，１
＋Ｔｘ_３・ｈ_３，１＋Ｔｘ_４・ｈ_４，１
Ｒｘ_２＝Ｔｘ_１・ｈ_１，２＋Ｔｘ_２・ｈ_２，２
＋Ｔｘ_３・ｈ_３，２＋Ｔｘ_４・ｈ_４，２
Ｒｘ_３＝Ｔｘ_１・ｈ_１，３＋Ｔｘ_２・ｈ_２，３
＋Ｔｘ_３・ｈ_３，３＋Ｔｘ_４・ｈ_４，３
Ｒｘ_４＝Ｔｘ_１・ｈ_１，４＋Ｔｘ_２・ｈ_２，４
＋Ｔｘ_３・ｈ_３，４＋Ｔｘ_４・ｈ_４，４ Rx ₁ = Tx ₁ · h _1,1 + Tx ₂ · h _2,1
+ Tx ₃ · h _3,1 + Tx ₄ · h _4,1
Rx ₂ = Tx ₁ · h _1,2 + Tx ₂ · h _2,2
+ Tx ₃ · h _3,2 + Tx ₄ · h _4,2
Rx ₃ = Tx ₁ · h _1,3 + Tx ₂ · h _2,3
+ Tx ₃ · h _3,3 + Tx ₄ · h _4,3
Rx ₄ = Tx ₁ · h _1,4 + Tx ₂ · h _2,4
+ Tx ₃ · h _3,4 + Tx ₄ · h _4,4

これらの各受信信号に対して、前記した演算部２５において、前記４種類の送信信号と複素共役な次の４種類のローカル信号をそれぞれ乗算する。 Each of these received signals is multiplied by the following four types of local signals complex-conjugated with the four types of transmission signals in the arithmetic unit 25 described above.

Ｌ_１＝ｅ^−ｊωｔ
Ｌ_２＝ｅ^ｊωｔ
Ｌ_３＝ｅ^{−ｊω′ｔ}
Ｌ_４＝ｅ^ｊω′ｔ L ₁ = e ^−jωt
L ₂ = e ^jωt
L ₃ = e ^−jω′t
L ₄ = e ^jω′t

第１受信信号Ｒｘ_１に対する各ローカル信号の乗算結果Ｕ_１〜Ｕ_４は、それぞれ以下のようになる。 The multiplication results U _{1 to} U ₄ of the local signals with respect to the first received signal Rx ₁ are as follows.

Ｕ_１＝Ｌ_１・Ｒｘ_１
＝Ｌ_１・Ｔｘ_１・ｈ_１，１
＋Ｌ_１（Ｔｘ_２・ｈ_２，１＋Ｔｘ_３・ｈ_３，１＋Ｔｘ_４・ｈ_４，１）
＝ｈ_１，１＋Ｙ_１ U ₁ = L ₁ · Rx ₁
= L ₁・ Tx ₁・ h _1,1
+ L ₁ (Tx ₂ · h _2,1 + Tx ₃ · h _3,1 + Tx ₄ · h _4,1 )
= H _1,1 + Y ₁

Ｕ_２＝Ｌ_２・Ｒｘ_１
＝Ｌ_２・Ｔｘ_２・ｈ_２，１
＋Ｌ_２（Ｔｘ_１・ｈ_１，１＋Ｔｘ_３・ｈ_３，１＋Ｔｘ_４・ｈ_４，１）
＝ｈ_２，１＋Ｙ_２ U ₂ = L ₂ · Rx ₁
= L ₂ · Tx ₂ · h _2,1
+ L ₂ (Tx ₁ · h _1,1 + Tx ₃ · h _3,1 + Tx ₄ · h _4,1 )
= H _2,1 + Y ₂

Ｕ_３＝Ｌ_３・Ｒｘ_１
＝Ｌ_３・Ｔｘ_３・ｈ_３，１
＋Ｌ_３（Ｔｘ_１・ｈ_１，１＋Ｔｘ_２・ｈ_２，１＋Ｔｘ_４・ｈ_４，１）
＝ｈ_３，１＋Ｙ_３ U ₃ = L ₃ · Rx ₁
= L ₃・ Tx ₃・ h _3,1
+ L ₃ (Tx ₁ · h _1,1 + Tx ₂ · h _2,1 + Tx ₄ · h _4,1 )
= H _3,1 + Y ₃

Ｕ_４＝Ｌ_４・Ｒｘ_１
＝Ｌ_４・Ｔｘ_４・ｈ_４，１
＋Ｌ_４（Ｔｘ_１・ｈ_１，１＋Ｔｘ_２・ｈ_２，１＋Ｔｘ_３・ｈ_３，１）
＝ｈ_４，１＋Ｙ_４ U ₄ = L ₄ · Rx ₁
= L ₄・ Tx ₄・ h _4,1
+ L ₄ (Tx ₁ · h _1,1 + Tx ₂ · h _2,1 + Tx ₃ · h _3,1 )
= H _4,1 + Y ₄

また同様に、各受信信号Ｒｘ_２〜Ｒｘ_４に対する４つのローカル信号Ｌ_１〜Ｌ_４の乗算結果Ｕ_５〜Ｕ_１６が次のように得られる。 Similarly, the multiplication results U _{5 to} U _{16 of the} _four local signals L _{1 to} L ₄ for the reception signals Rx _{2 to} Rx ₄ are obtained as follows.

Ｕ_５＝Ｌ_１・Ｒｘ_２＝ｈ_１，２＋Ｙ_５
Ｕ_６＝Ｌ_２・Ｒｘ_２＝ｈ_２，２＋Ｙ_６
………
Ｕ_１５＝Ｌ_３・Ｒｘ_４＝ｈ_３，４＋Ｙ_１５
Ｕ_１６＝Ｌ_４・Ｒｘ_４＝ｈ_４，４＋Ｙ_１６ U ₅ = L ₁ · Rx ₂ = h _{1, 2} + Y ₅
U ₆ = L ₂ · Rx ₂ = h _2,2 + Y ₆
………
U ₁₅ = L ₃ · Rx ₄ = h _3,4 + Y ₁₅
U ₁₆ = L ₄ · Rx ₄ = h _4,4 + Y ₁₆

上記各乗算結果は、前記同様に送信信号とローカル信号の交流分が互いに相殺されて直流帯に変換された伝達関数ｈ_１，１〜ｈ_４，４と、送信信号とローカル信号の周波数の和成分または差成分を含む交流成分Ｙ_１〜Ｙ_１６と和でそれぞれ表されるので、前記同様に、各乗算結果Ｕ_１〜Ｕ_１６から、伝達関数抽出手段３０のローパスフィルタにより直流分を抽出することで、１６個の伝達関数ｈ_１，１〜ｈ_４，４を求めることができる。 As described above, the multiplication results are as follows: the transfer functions h _{1,1 to} h _{4,4 in} which the AC components of the transmission signal and the local signal are canceled each other and converted into the DC band, and the sum of the frequencies of the transmission signal and the local signal. Since each component is expressed as a sum with the AC components Y _{1 to} Y ₁₆ including the difference component, the DC component is extracted from the multiplication results U _{1 to} U ₁₆ by the low-pass filter of the transfer function extracting unit 30 as described above. Thus, 16 transfer functions h _{1,1 to} h _4,4 can be obtained.

なお、出力ポート数ｍが１の場合には、上記第１受信信号に対する４つの乗算結果Ｕ_１〜Ｕ_４から４つの伝達関数ｈ_１，１〜ｈ_４，１を求め、出力ポート数ｍが２の場合には、上記第１受信信号と第２受信信号に対する計８つの乗算結果Ｕ_１〜Ｕ_８から８つの伝達関数ｈ_１，１〜ｈ_４，２を求める。さらに出力ポート数ｍが３の場合には、上記第１受信信号、第２受信信号、第３受信信号に対する計１２の乗算結果Ｕ_１〜Ｕ_１２から１２の伝達関数ｈ_１，１〜ｈ_４，３を求める。 When the number of output ports m is 1, four transfer functions h _{1,1 to} h _4,1 are obtained from the four multiplication results U _{1 to} U ₄ for the first received signal, and the number of output ports m is In the case of 2, eight transfer functions h _{1,1 to} h _4,2 are obtained from a total of eight multiplication results U _{1 to} U ₈ for the first received signal and the second received signal. Further, when the number m of output ports is 3, a total of 12 multiplication results U _{1 to} U ₁₂ to 12 transfer functions h _{1, 1 to} h _{4 for} the first received signal, the second received signal, and the third received signal. _{, 3} is obtained.

また、入力ポート数ｎがさらに多い場合には、さらに異なる周波数（ω″）の送信信号を与えることで対応可能であるが、その周波数としては、前記したように、乗算処理で得られる直流分をフィルタで抽出する際に急峻なカットオフ特性が要求されることが無いように、それぞれが０（直流）に近くなく（高周波）、その差の絶対値｜ω−ω′｜、｜ω−ω″｜、｜ω′−ω″｜も０（直流）に近くないことが要求される。 Further, when the number of input ports n is larger, it can be dealt with by giving a transmission signal of a different frequency (ω ″). As described above, the frequency can be obtained by the DC component obtained by the multiplication process. Are not close to 0 (direct current) (high frequency) so that a steep cut-off characteristic is not required when extracting them with a filter, the absolute values of the differences | ω−ω ′ |, | ω− It is required that ω ″ | and | ω′−ω ″ | are not close to 0 (direct current).

この条件を満たす例としては、ω＝２ω′＝４ω″またはその逆の４ω＝２ω′＝ωの関係がある。 As an example satisfying this condition, there is a relationship of ω = 2ω ′ = 4ω ″ or vice versa 4ω = 2ω ′ = ω.

本発明の伝搬路模擬回路評価方法の手順を示すフローチャートThe flowchart which shows the procedure of the propagation path simulation circuit evaluation method of this invention 本発明の伝搬路模擬回路評価装置の構成を示す図The figure which shows the structure of the propagation path simulation circuit evaluation apparatus of this invention 実施形態の要部の構成例を示す図The figure which shows the structural example of the principal part of embodiment. 実施形態の要部の構成例を示す図The figure which shows the structural example of the principal part of embodiment. 実施形態の要部の構成例を示す図The figure which shows the structural example of the principal part of embodiment. ２×１の伝搬路模擬回路の例を示す図The figure which shows the example of a 2 * 1 propagation path simulation circuit ４×４の伝搬路模擬回路とそれに入力する信号例を示す図4 shows a 4 × 4 propagation path simulation circuit and a signal example input to the circuit ２×２のＭＩＭＯシステムの例を示す図Diagram showing an example of a 2x2 MIMO system

Explanation of symbols

１……伝搬路模擬回路、２ａ〜２ｄ……入力ポート、３ａ〜３ｃ……出力ポート、２０……伝搬路模擬回路評価装置、２１……送信信号入力手段、２２……Ａ／Ｄ変換器、２３……受信データメモリ、２５……演算手段、３０……伝達関数抽出手段、３０ａ〜３０ｄ……ローパスフィルタ、３５……評価演算部 DESCRIPTION OF SYMBOLS 1 ... Propagation path simulation circuit, 2a-2d ... Input port, 3a-3c ... Output port, 20 ... Propagation path simulation circuit evaluation apparatus, 21 ... Transmission signal input means, 22 ... A / D converter , 23... Received data memory, 25... Computing means, 30... Transfer function extracting means, 30 a to 30 d. Low pass filter, 35.

Claims

It has n input ports (n is an integer of 2 or more) and m output ports (m is an integer), and the input port and output port are connected by a circuit that simulates n × m propagation paths. A propagation path simulation circuit evaluation method for evaluating a propagation path simulation circuit,
For the n input ports of the propagation path simulation circuit, there are n ^types of transmission signals represented by complex numbers e ^jωt , transmission signals complex with them, or transmission signals having different frequencies from those transmission signals. A transmission signal input step (S1) for assigning different transmission signals so as not to overlap each other and inputting them in parallel;
A calculation step of multiplying reception signals output from the m output ports of the propagation path simulation circuit by n types of transmission signals given in parallel to the n input ports and complex conjugate local signals, respectively. (S3),
From the result of multiplication of the received signal, the signal component converted into DC by the AC component of the transmission signal and the local signal canceling each other by the multiplication of the local signal and the complex conjugate frequency component is converted into the DC of the propagation path simulation circuit. A transfer function extracting step (S4) for separating and extracting from other AC components as a transfer function of the propagation path,
A propagation path simulation circuit evaluation method, comprising: evaluating the propagation path simulation circuit based on the extracted transfer function.

The number of input ports n and the number of output ports m of the propagation path simulation circuit are both 2,
In the transmission signal input step,
A first transmission signal represented by a complex number e ^jωt is given to the first input port, and a second transmission signal represented by a complex number e ^−jωt conjugate with the first transmission signal is given to the second input port,
In the calculation stage,
The first received signal output from the first output port is multiplied by a first local signal represented by a complex number e ^−jωt conjugate with the first transmission signal, and a complex number e conjugate with the second transmission signal. The second local signal represented by ^jωt is multiplied, and the second received signal output from the second output port is multiplied by the first local signal and the second local signal. Each with multiplication processing,
In the transfer function extraction step,
2. The propagation according to claim 1, wherein DC signal components respectively included in the results of the four types of multiplication processing are separated and extracted from other AC components as transfer functions of four propagation paths of the propagation path simulation circuit. Road simulation circuit evaluation method.

It has n input ports (n is an integer of 2 or more) and m output ports (m is an integer), and the input port and output port are connected by a circuit that simulates n × m propagation paths. A propagation path simulation circuit device for evaluating a propagation path simulation circuit,
For the n input ports of the propagation path simulation circuit, there are n ^types of transmission signals represented by complex numbers e ^jωt , transmission signals complex with them, or transmission signals whose frequencies are changed with respect to those transmission signals. Transmission signal input means (21) for assigning and transmitting different transmission signals in parallel so as not to overlap each other,
Arithmetic means for multiplying received signals output from m output ports of the propagation path simulation circuit by n kinds of transmission signals given in parallel to the n input ports and complex conjugate local signals, respectively. (25) and
From the result of multiplication of the received signal, the signal component converted into DC by the AC component of the transmission signal and the local signal canceling each other by the multiplication of the local signal and the complex conjugate frequency component is converted into the DC of the propagation path simulation circuit. A transfer function extracting means (30) for separating and extracting from other AC components as a transfer function of the propagation path,
A propagation path simulation circuit evaluation apparatus that evaluates the propagation path simulation circuit based on the transfer function extracted by the transfer function extraction means.

The number of input ports n and the number of output ports m of the propagation path simulation circuit are both 2,
The transmission signal input means includes
A first transmission signal represented by a complex number e ^jωt is given to the first input port, and a second transmission signal represented by a complex number e ^−jωt conjugate with the first transmission signal is given to the second input port. Configured,
The computing means is
The first received signal output from the first output port is multiplied by a first local signal represented by a complex number e ^−jωt conjugate with the first transmission signal, and a complex number e conjugate with the second transmission signal. The second local signal represented by ^jωt is multiplied, and the second received signal output from the second output port is multiplied by the first local signal and the second local signal. Each of which performs a multiplication process,
The transfer function extracting means includes
4. The propagation according to claim 3, wherein DC signal components respectively included in the results of the four types of multiplication processing are separated and extracted from other AC components as transfer functions of four propagation paths of the propagation path simulation circuit. Road simulation circuit evaluation device.