JP2012039170A - Transmission quality evaluation auxiliary device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission quality evaluation auxiliary device that is comprised of a plurality of distributors, a plurality of phase shifters, and cable communication lines, and that can construct a transmission line to evaluate a transmission characteristic from high correlation environment to low correlation environment in the transmission line by adjusting phases of the phase shifters without obtaining radio license or constructing a large scale transmission and reception system.SOLUTION: A transmission quality evaluation auxiliary device simulates a transmission line between communication devices in order to evaluate transmission quality between the communication devices performing multiplex transmission and reception of signals at the same time and using the same frequency channel. The transmission quality evaluation auxiliary device comprises: a plurality of input ports for inputting signals from a transmission device; distributors connected to the respective input ports for distributing the input signals; a plurality of output ports for outputting signals to a reception device; synthesizers connected to the respective output ports for synthesizing the output signals; communication lines for wiredly connecting the respective distributors and the respective synthesizers; and phase shifters connected in the respective middle of the communication lines.

Description

  The present invention uses a transmission line constructed in a pseudo-wired manner instead of an actually used transmission line for evaluating the transmission quality of a communication device that performs transmission and reception at a plurality of output ports and a plurality of input ports. The present invention relates to a transmission quality evaluation auxiliary device that simulates a transmission line.

  MIMO (Multiple Input Multiple Output) communication is known as a technology that can dramatically increase the communication speed. This is because a plurality of signals are transmitted from a plurality of output ports of the transmission side communication device (transmission device) at the same frequency channel and at the same time, and different reception signals are received from a plurality of input ports of the reception side communication device (reception device). This is a technology that increases communication speed. This technology can increase the communication speed in proportion to the number of input / output ports in the wired / wireless communication technology. As a high-speed wireless access system, MIMO communication is introduced, for example, in the wireless LAN standard IEEE 802.11n (see Non-Patent Document 1, for example).

  Since the communication speed in MIMO communication is determined depending on the propagation environment, the same communication speed cannot be achieved anytime and anywhere. FIG. 14 shows a configuration in the case of wireless communication. In FIG. 14, 101 is a transmission device, 103-1 to N are transmission antenna elements, 104-1 to M are reception antenna elements, and 102 is a reception device. Even in a wireless transmission path by wireless communication, the communication speed can be increased as the correlation of paths connecting antennas is lower (multipath environment).

Masahiro Morikura, Shuji Kubota, “Revised Third Edition 802.11 High-Speed Wireless LAN Textbook”, Impress R & D, March 27, 2008

  By the way, in order to confirm the characteristics of MIMO communication in an actual propagation environment, in the case of wireless communication, acquisition of a radio wave license, in optical communication, construction of a laser and a large-scale optical fiber transceiver, communication in a metal cable However, in any case, it is necessary to try various connection forms, and in any case, a great burden is required for constructing a transmission path for verification, and there is a problem that construction of an actual transmission path has a great difficulty. .

  The present invention has been made in view of such circumstances, and includes a plurality of distributors, a plurality of phase shifters, and a wired communication line, and has a high correlation in a propagation environment by adjusting the phase of the phase shifter. To provide a transmission quality evaluation auxiliary device capable of constructing a propagation environment for evaluating transmission characteristics without obtaining a radio license or constructing a large-scale transmission / reception system from the environment to an environment with low correlation With the goal.

  The present invention is a transmission quality evaluation auxiliary device for simulating a transmission path between the communication devices in order to evaluate the transmission quality between the communication devices performing multiplex transmission / reception of signals using the same time and the same frequency channel. A plurality of input ports for inputting signals from the transmission device, a distributor connected to each of the input ports and distributing the input signals, a plurality of output ports for outputting signals to the reception device, and the output ports A combiner that combines the output signals, a communication line that connects each of the distributors and the combiner in a wired manner, and a phase shifter that is connected in the middle of each of the communication lines; It is provided with.

  The present invention is further characterized by further comprising a phase adjusting device that adjusts a phase rotation amount of each of the phase shifters.

  In the present invention, when the number of the input ports and the number of the output ports are each set to the factorial of 2, and the connection relationship between the input ports and the output ports is regarded as a matrix, −1 of the orthogonal matrix Only the phase rotation amount of the phase shifter at a position corresponding to is controlled.

  The present invention is a transmission quality evaluation auxiliary device for simulating a transmission path between the communication devices in order to evaluate the transmission quality between the communication devices performing multiplex transmission / reception of signals using the same time and the same frequency channel. A plurality of input ports for inputting signals from the transmission device, a distributor connected to each of the input ports and distributing the input signals, a plurality of output ports for outputting signals to the reception device, and the output ports And a synthesizer that synthesizes output signals, and a communication line that connects each of the distributors and each of the synthesizers in a wired manner, the number of the input ports, and the number of the output ports When the number is a factorial of 2 and the connection relationship between the input port and the output port is regarded as a matrix, a phase shifter is provided in the middle of each communication line at a position corresponding to -1 of the orthogonal matrix. And said that there were pictures.

  The present invention is characterized in that the phase rotation amount of the phase shifter is changed at an arbitrary speed.

  The present invention is characterized in that the phase rotation amount of the phase shifter is changed, and the correlation of the simulated transmission path is changed at an arbitrary speed.

  The present invention is characterized in that an attenuator is further connected between the input port and the output port.

  The present invention is characterized in that the attenuation amount of the attenuator is changed at an arbitrary speed.

  According to the present invention, when evaluating a MIMO communication transmission apparatus that performs communication using a plurality of transmission / reception ports, a pseudo transmission path is formed by a wired transmission path including a distributor, a phase shifter, and a combiner. As a result, it is possible to easily reproduce from a good situation to a bad situation in the propagation environment of MIMO communication and to perform evaluation in that situation.

It is a block diagram which shows the structure of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the 3rd Embodiment of this invention. It is a block diagram which shows the modification of the structure of the 3rd Embodiment of this invention. It is explanatory drawing which shows the parameter used for the measurement. It is explanatory drawing which shows the result of phase rotation amount 0 degree. It is explanatory drawing which shows the result of phase rotation amount 50 degrees. It is explanatory drawing which shows the result of phase rotation amount 180 degrees. It is a block diagram which shows the structure of the 4th Embodiment of this invention. It is a block diagram which shows the structure of the 5th Embodiment of this invention. It is explanatory drawing which shows the structure of the table which defined the relationship between the correlation value and phase rotation amount in the 6th Embodiment of this invention. It is a block diagram which shows the structure of the 7th Embodiment of this invention. It is a block diagram which shows the structure of the 8th Embodiment of this invention. It is a block diagram which shows the structure of the transmitter in the case of using a wireless transmission path, and a receiver.

<First Embodiment>
Hereinafter, a transmission quality evaluation assisting apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. In this figure, reference numerals 101 and 102 are the same devices as the transmission device 101 and the reception device 102 shown in FIG. The apparatus configuration shown in FIG. 1 is different from the apparatus configuration shown in FIG. 14 in that the wireless transmission path shown in FIG. 14 is simulated by the transmission quality evaluation auxiliary device 111 shown in FIG.

  The transmission quality evaluation auxiliary device 111 in the first embodiment includes a plurality (N; N is a natural number of 2 or more) of input ports 105-1 to N, and a plurality of (N) distributors 106-1 to 106-1 to N. , A plurality of phase shifters 107, a plurality of cables 108, a plurality of (M; M is a natural number of 2 or more) combiners 109-1 to M, and a plurality (M) of output ports 110-1 to M. Composed.

  As a specific connection method, as shown in FIG. 1, a distributor 106 is connected to each input port 105. The distributor 106 is connected to a cable to which the phase shifter 107 is connected. A synthesizer 109 is connected to each output port 110. The combiner 109 is connected to a cable connected to each distributor. When the MIMO communication is evaluated using the transmission quality evaluation auxiliary device 111, each transmission port of the transmission device 101 is connected to each input port 105-1 to 105-1. In addition, the evaluation can be performed by connecting the output port 110-1 to the output port 110-1 to the reception port of the reception device 102.

  When the transmitting device 101 or the receiving device 102 is a wireless transceiver, an antenna element is usually connected to the transmitting port or the receiving port, but the input port or output port of the transmission quality evaluation auxiliary device 111 is not connected. In the case of connection, a method of removing the antenna element and connecting directly or using a connector is used. Alternatively, antenna elements are also connected to the input ports 105-1 to N and output ports 110-1 to 110-M of the transmission quality evaluation auxiliary device 111, and the antenna elements of the transmission device 101 or the reception device 102 and the transmission quality evaluation auxiliary device 111 are connected. Signals may be transmitted and received between the antenna elements.

  Next, each device constituting the transmission quality evaluation auxiliary device 111 will be described. The input port 105 and the output port 110 are ports configured by connectors used for communication. The distributor 106 distributes the signal from the input port by the number to be distributed. The phase shifter 107 changes the phase rotation amount of the signal from the input port. The cable 108 transmits a signal. A combiner 109 combines and outputs a plurality of signals.

Next, an evaluation method for MIMO communication will be described. One of the causes of deterioration in communication capacity when performing MIMO communication is correlation of transmission paths. When the correlation is high, the propagation environment is deteriorated, and when the correlation is low, the propagation environment is improved. The correlation is determined by the phase rotation amount of each transmission path in the transmission path. Therefore, various propagation environments can be constructed by changing the rotation amount of the phase shifter 107 in FIG. At this time, the propagation coefficient between the i-th distributor 106-i and the j-th combiner 109-j is set to h _ji . At this time, if the phaser 107 is included in this path,
h _ij = a _ij exp (j (θ _ij + φ _ij )) (1)
Here, a _ij is an attenuation coefficient between distributor 106-i and synthesizer 109-j, and θ _ij [rad] is a phase rotation term due to circuit characteristics between distributor 106-i and synthesizer 109-j. , Φ _ij [rad] is a phase rotation set by the phase shifter 107.

ここで、Ｍは出力数、Ｎは入力数を示している。式（２）の行列式は、各位相器１０７の回転量を調整することで変化させることが可能であるので、例えば、行列式を大きくなるように位相器を調整することで良い伝搬環境を作ることができ、行列式を小さくするにように位相器を調整することで悪い伝搬環境を作ることができる。従って、伝搬環境が良い状態から悪い状態まですべてに対してＭＩＭＯ通信を評価することが可能である。 Next, an example of a method for adjusting the phase rotation amount will be described. The determinant shown in Expression (2) is used as an expression for determining whether the propagation environment is good or bad.
C = det (H) (2)
H is a matrix composed of the propagation coefficient represented by Expression (1). In MIMO communication, it is also called a propagation channel. H can be expressed as in Equation (3).

Here, M indicates the number of outputs, and N indicates the number of inputs. Since the determinant of Expression (2) can be changed by adjusting the rotation amount of each phase shifter 107, for example, a good propagation environment can be obtained by adjusting the phase shifter so as to increase the determinant. It is possible to create a bad propagation environment by adjusting the phase shifter so as to reduce the determinant. Therefore, it is possible to evaluate MIMO communication for everything from a good propagation environment to a bad propagation environment.

  As a signal to be input, a radio signal may be input, an optical signal may be input, or power may be input.

  As described above, the transmission quality evaluation auxiliary device 111 in the first embodiment includes the input ports 105-1 to N, the output ports 110-1 to M, the distributors 106-1 to 106-N, the phase shifter 107, the cable 108, and the synthesis. By using the devices 109-1 to 109 -M, it is possible to evaluate transmission characteristics in MIMO communication by constructing a wired virtual transmission path.

<Second Embodiment>
Next, with reference to FIG. 2, a transmission quality evaluation auxiliary device according to the second embodiment of the present invention will be described. FIG. 2 is a block diagram showing the configuration of the embodiment. In the transmission quality evaluation auxiliary apparatus 112 shown in FIG. 2, the same parts as those in the transmission quality evaluation auxiliary apparatus 111 shown in FIG. The apparatus shown in this figure is different from the apparatus shown in FIG. 1 in that a phase adjusting device 121 that adjusts each phase of the phase shifter 107 is provided. The phase adjusting device 121 easily constructs transmission paths having different correlations by adjusting the amount of phase rotation of each phase shifter 107.

  As described above, the transmission quality evaluation auxiliary device 112 in the second embodiment can easily construct transmission paths having different correlations by adjusting the phase rotation amount of each phase shifter using the phase adjustment device.

<Third Embodiment>
Next, with reference to FIG. 3, a transmission quality evaluation auxiliary device according to the third embodiment of the present invention will be described. FIG. 3 is a block diagram showing the configuration of the embodiment. In the transmission quality evaluation auxiliary apparatus 113 shown in FIG. 3, the same parts as those in the transmission quality evaluation auxiliary apparatus 111 shown in FIG. The apparatus shown in this figure differs from the apparatus shown in FIG. 1 in that the number of input ports and the number of output ports are set to a factorial of 2 (in the example shown in FIG. And the output ports 110-1 to 110-4 are regarded as a matrix, various propagation environments are created by adjusting only the phase shifter 107 at a position corresponding to -1 of the orthogonal matrix. This is the point.

ｎ＝８以降は、式（８）によって生成される。

Here, the position and number of phase shifters 107 corresponding to −1 of the orthogonal matrix will be described. An orthogonal matrix (code) is a matrix (code) used to secure an independent communication channel, and is also called a Walsh matrix (code). The orthogonal matrix W _n is a matrix represented by the equations (4) to (7), and appears only when n = 2 ^m (m = 1, 2, 3, 4,...).

After n = 8, it is generated by equation (8).

  It is possible to evaluate MIMO transmission from a good propagation environment to a bad propagation environment only by adjusting the orthogonal matrix shown above and the propagation channel H and adjusting only the phase shifter 107 at the position corresponding to −1 of the orthogonal matrix. It becomes. Here, the rows and columns of the matrix respectively correspond to the input ports 105-1 to 10-4 and the output ports 110-1 to 110-4 of the transmission quality evaluation auxiliary device 113, and each element of the matrix corresponds to the corresponding input port and output. The cable that connects the ports will be specified. This is because the determinants of the orthogonal matrix are all maximized, and the adjustment of the propagation environment can be changed to the maximum by adjusting only the phase shifter 107 at the position corresponding to −1 of the orthogonal matrix.

  That is, when the evaluation is to be performed in the best propagation environment, the phase rotation amount of the phase shifter 107 at the position corresponding to −1 of the orthogonal matrix may be adjusted to be 180 ° compared to other paths. Further, when it is desired to evaluate in the worst propagation environment, the phase rotation amount of the phase shifter 107 at the position corresponding to −1 of the orthogonal matrix may be adjusted to be 0 ° compared to other paths. Therefore, by adjusting only a part of the phase shifters 107 (positions corresponding to −1 of the orthogonal matrix), it is possible to evaluate all from the best propagation environment to the worst propagation environment.

  However, it is necessary to adjust the phase shifter 107 of the path corresponding to 1 of the orthogonal matrix in advance so that the phase difference of each path is 0 °. This may be adjusted by changing the type of cable instead of the phase shifter 107.

  Further, as shown in FIG. 4, a phase adjustment device 121 is provided in the transmission quality evaluation auxiliary device 114, and the phase rotation amount of only the phase shifter 107 corresponding to −1 of the orthogonal matrix is controlled by the phase adjustment device 121. Good.

  Next, the measurement result using the transmission quality evaluation auxiliary apparatus 113 in the third embodiment will be described. FIG. 5 shows parameters used in the measurement for evaluating the MIMO transmission. 6, 7, and 8, the phase rotation amount of the phase shifter 107 at the position corresponding to −1 of the orthogonal matrix is set to 0 ° (FIG. 6), 50 ° (FIG. 7), and 180 ° (FIG. 8). The result of signal point arrangement of each transmission stream at the time is shown. The stream here refers to each data when performing spatial multiplexing by the MIMO technique.

  As shown in FIG. 6, the result of the phase rotation amount 0 ° is the same in all the paths, the determinant becomes smaller, the propagation environment becomes worse, and even the decoding is almost wrong. Further, as shown in FIG. 7, the result of the phase rotation amount of 50 ° is that the determinant value is increased by changing the phase rotation amount, and the result is slightly correct, but is almost correctly received. Furthermore, as shown in FIG. 8, it can be seen that the result of the phase rotation amount 180 ° can be received with almost no error as a result of decoding because the determinant has the largest value and the propagation environment is improved. .

  As described above, the transmission quality evaluation auxiliary apparatuses 113 and 114 in the third embodiment can evaluate from a good propagation environment to a bad propagation environment by adjusting only a few phase shifters 107.

<Fourth Embodiment>
Next, with reference to FIG. 9, a transmission quality evaluation auxiliary device according to the fourth embodiment of the present invention will be described. FIG. 9 is a block diagram showing the configuration of the embodiment. In the transmission quality evaluation auxiliary apparatus 115 shown in FIG. 9, the same parts as those in the transmission quality evaluation auxiliary apparatus 111 shown in FIG. The apparatus shown in this figure is different from the apparatus shown in FIG. 1 in that the number of input ports and the number of output ports are set to a factorial of 2 (in the example shown in FIG. 9, the number of ports is 4), and the input ports 105-1 to 10-4. The phase shifter 17 is connected only to a position corresponding to −1 of the orthogonal matrix when the connection relationship between the output ports 110-1 to 110-4 is regarded as a matrix. However, the phase rotation amount difference of each path corresponding to 1 of the orthogonal matrix is set to 0 ° in advance.

  As described above, the transmission quality evaluation auxiliary device 115 according to the fourth embodiment is configured by using only a small number of phase shifters 107 by previously configuring the phase rotation amount difference of each path corresponding to 1 of the orthogonal matrix as 0 °. can do.

<Fifth Embodiment>
Next, with reference to FIG. 10, a transmission quality evaluation auxiliary device according to the fifth embodiment of the present invention will be described. FIG. 10 is a block diagram showing the configuration of the embodiment. In the transmission quality evaluation auxiliary apparatus 116 shown in FIG. 10, the same parts as those of the transmission quality evaluation auxiliary apparatus 112 shown in FIG. The apparatus shown in this figure is different from the apparatus shown in FIG. 2 in that a phase change device 122 that changes the phase of the phase shifter 107 at an arbitrary speed is further provided.

  The phase change device 122 controls the operation of the phase adjustment device 121 and causes the phase shifter 107 to change the phase rotation amount at an arbitrary speed. By adding control for arbitrarily changing the phase rotation amount of each phase shifter 107 in time series by the phase change device 122, a propagation environment in which the phase rotation amount changes in time series can be created. Therefore, it is possible to evaluate when there is a time variation in the phase rotation amount.

  As described above, the transmission quality evaluation auxiliary device 116 in the fifth embodiment controls the phase rotation amount for each time using the phase change device 122 that changes the phase rotation amount of the phase shifter 107 at an arbitrary speed. Thus, it is possible to perform evaluation in a state where there is a time variation of the transmission line close to the real environment.

<Sixth Embodiment>
Next, a transmission quality evaluation auxiliary device according to the sixth embodiment of the present invention will be described with reference to FIG. FIG. 11 is an explanatory diagram illustrating a configuration of a table that defines the relationship between the correlation value and the phase rotation amount stored in the transmission quality evaluation auxiliary device according to the embodiment. Various transmission paths can be created by adjusting the amount of phase rotation, but the number of combinations is enormous. Therefore, the sixth embodiment defines a combination of each correlation value (1, 2, 3, 4, 5: 1 has low correlation and 5 has high correlation) and a phase rotation amount that can achieve each correlation value. This table is stored in advance in the transmission quality evaluation auxiliary device.

  In this way, several combinations of phase rotation amounts capable of generating a plurality of correlation values are prepared in advance and stored in the apparatus, and the phase rotation amount of the phase shifter 107 is adjusted only within the combinations. Thus, MIMO communication can be easily evaluated.

<Seventh Embodiment>
Next, with reference to FIG. 12, a transmission quality evaluation auxiliary apparatus according to the seventh embodiment of the present invention will be described. FIG. 12 is a block diagram showing the configuration of the embodiment. In the transmission quality evaluation auxiliary apparatus 117 shown in FIG. 12, the same parts as those in the transmission quality evaluation auxiliary apparatus 116 shown in FIG. The apparatus shown in this figure differs from the apparatus shown in FIG. 10 in that a phase shifter 119 having an attenuation function is used in place of the phase shifter 107 so that not only the phase but also the attenuation is changed for evaluation. This is the point.

  Thus, by connecting the phase shifter 119 having an attenuator, the propagation loss of each transmission line can be changed. In actual transmission, it is rare that the propagation loss of each path matches. Therefore, by using the phase shifter 119 having an attenuator, it is possible to evaluate the transmission path closer to the actual environment.

<Eighth Embodiment>
Next, with reference to FIG. 13, a transmission quality evaluation auxiliary device according to the eighth embodiment of the present invention will be described. FIG. 13 is a block diagram showing a configuration of the embodiment. In the transmission quality evaluation auxiliary apparatus 118 shown in FIG. 13, the same parts as those in the transmission quality evaluation auxiliary apparatus 117 shown in FIG. The apparatus shown in this figure is different from the apparatus shown in FIG. 12 in that a phase / attenuation adjusting device 123 and a phase / attenuation changing device 124 are provided in place of the phase adjusting device 121 and the phase changing device 122, respectively. This is also the point that the attenuation is adjusted.

  Thus, by providing the phase / attenuation adjusting device 123 capable of adjusting the phase and attenuation, and the phase / attenuation changing device 124 capable of changing the phase and attenuation at an arbitrary speed, the phase and attenuation can be arbitrarily set. Therefore, it is possible to evaluate in an environment that is simple and close to an actual transmission path.

  As described above, signal transmission is performed by wire or wireless from a transmission device having a plurality of transmission ports to a reception device having a plurality of reception ports, such as MIMO (Multiple-Input Multiple-Output) technology. When evaluating transmission quality in a system, it is necessary to simulate transmission paths in various states. The transmission quality evaluation auxiliary device described above has a configuration in which each input port is connected to a distributor and each output port is connected to a combiner. Further, each distributor inputs an input to each combiner. Each synthesizer is configured to synthesize and output the inputs. The distributor and the combiner are connected by a wired communication line, and a phase shifter is disposed between the distributor and the combiner.

At this time, the i-th distributor between the j-th synthesizer, a phase shift amount phi _ij by phaser relationship of the propagation coefficient h _ji is given by Equation (1), the propagation environment h _ji Based on this, a propagation channel H is given (formula (3)), and an amount C representing the propagation environment is given (formula (2)). As is apparent from the above description, the propagation environment simulated by the transmission quality evaluation auxiliary device can be controlled by adjusting the phase shift amount φ _ij of each phase shifter. Therefore, each transmission port of the transmission device is connected to each input port of the transmission quality evaluation auxiliary device, and each output port of the transmission quality evaluation auxiliary device is connected to each reception port of the reception device, so that the phase shift amount of each phase shifter can be adjusted. For example, transmission paths in various states can be simulated in the target transmission / reception system, and transmission quality can be easily evaluated. That is, in the transmission quality evaluation auxiliary device of the present invention, in a system that performs signal transmission by wire or wireless from a transmission device having a plurality of transmission ports to a reception device having a plurality of reception ports, the transmission environment evaluation assisting device The effect that even a bad situation can be easily reproduced can be obtained.

  Instead of the actual transmission path used to evaluate the transmission quality of communication devices that transmit and receive at multiple output ports and multiple input ports, the transmission path can be changed by using a pseudo-wired transmission path. It can be applied to applications where simulation is essential.

  DESCRIPTION OF SYMBOLS 101 ... Transmitting device, 102 ... Receiving device, 105-1 to N ... Input port, 106-1 to N ... Distributor, 107 ... Phaser, 108 ... Cable, 109 -1 to M: combiner, 110-1 to M: output port, 111, 112, 113, 114, 115, 116, 117, 118 ... transmission quality evaluation auxiliary device, 119 ... attenuation , Phase adjuster, 122 ... phase change device, 123 ... phase / attenuation adjuster, 124 ... phase / attenuation change device

Claims (8)

In order to evaluate the transmission quality between communication devices that perform multiplex transmission / reception of signals using the same time and the same frequency channel, a transmission quality evaluation auxiliary device that simulates a transmission path between the communication devices,
A plurality of input ports for inputting signals from the transmission device;
A distributor connected to each of the input ports and distributing an input signal;
A plurality of output ports for outputting signals to the receiving device;
A synthesizer connected to each of the output ports for synthesizing an output signal;
A communication line that connects each of the distributors and each of the combiners in a wired manner;
And a phase shifter connected in the middle of each of the communication lines.   The transmission quality evaluation auxiliary device according to claim 1, further comprising a phase adjusting device for adjusting a phase rotation amount of each of the phase shifters. The number of input ports and the number of output ports are each set to a factorial of 2,
2. The control unit according to claim 1, wherein when the connection relation between the input port and the output port is regarded as a matrix, only the phase rotation amount of the phase shifter at a position corresponding to -1 of the orthogonal matrix is controlled. Or the transmission quality evaluation auxiliary device according to 2. In order to evaluate the transmission quality between communication devices that perform multiplex transmission / reception of signals using the same time and the same frequency channel, a transmission quality evaluation auxiliary device that simulates a transmission path between the communication devices,
A plurality of input ports for inputting signals from the transmission device;
A distributor connected to each of the input ports and distributing an input signal;
A plurality of output ports for outputting signals to the receiving device;
A synthesizer connected to each of the output ports for synthesizing an output signal;
A communication line for connecting each of the distributors and each of the combiners by wire;
The number of input ports and the number of output ports are each set to a factorial of 2,
A transmission quality evaluation comprising a phase shifter in the middle of each communication line at a position corresponding to -1 of an orthogonal matrix when the connection relationship between the input port and the output port is regarded as a matrix. Auxiliary device.   5. The transmission quality evaluation auxiliary device according to claim 1, wherein the phase rotation amount of the phase shifter is changed at an arbitrary speed.   6. The transmission quality evaluation auxiliary device according to claim 1, wherein the phase rotation amount of the phase shifter is changed to change the correlation of the simulated transmission path at an arbitrary speed.   The transmission quality evaluation auxiliary device according to any one of claims 1 to 6, further comprising an attenuator connected between the input port and the output port.   8. The transmission quality evaluation auxiliary device according to claim 7, wherein the attenuation amount of the attenuator is changed at an arbitrary speed.

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