Channel conduction test apparatus, method, control apparatus, and storage medium

Abstract

The application provides a channel transmission test device, a method, a control device and a storage medium. The channel transmission test method comprises the following steps: receiving M input signals, and dividing each signal in the M input signals into M first branch signals; performing phase adjustment processing on a target branch signal in the M first branch signals corresponding to each input signal to obtain an adjusted signal; performing attenuation on M-1 first branch signals other than the target branch signal in the M first branch signals corresponding to each input signal to obtain M-1 attenuated signals; and synthesizing the adjusted signal corresponding to each input signal and the M-1 attenuated signals to obtain M output signals. Through the application, controllable adjustment of the correlation of the output signals can be realized while reducing the hardware complexity.

Description

Technical Field

[0001] This application relates to communication technology, and more particularly to a channel conduction testing device, method, control device, and storage medium. Background Technology

[0002] In Multiple-Input Multiple-Output (MIMO) wireless communication systems, channel correlation affects the ill-conditioned nature of the channel response matrix. This means the channel response matrix is ​​extremely sensitive to input disturbances during numerical calculations, leading to unstable results and significantly amplified errors when solving linear equations or performing matrix operations, further impacting communication quality and throughput. Correlation techniques typically assess channel correlation through antenna correlation testing or extraction of channel state information during communication. However, these methods are easily affected by factors such as the relative positions of transceivers, antenna performance, spatial obstruction, and the electromagnetic environment. The testing process often involves multiple parameters changing in tandem, resulting in insufficient consistency and comparability between different test results, and making experimental reproduction difficult.

[0003] Meanwhile, altering channel correlation by changing spatial location or other means can easily introduce signal strength fluctuations, making it difficult to analyze the impact of channel correlation on communication performance under controlled variable conditions. Furthermore, existing channel testing devices typically involve separate control of multiple signal paths when implementing correlation adjustment, resulting in a large number of components, complex structures, and high hardware costs. Moreover, the correlation adjustment range and accuracy are easily affected by other channel coupling relationships. Summary of the Invention

[0004] This application provides a channel conduction testing device, method, control device, and storage medium that can achieve controllable adjustment of output signal correlation while reducing hardware complexity.

[0005] The technical solution of this application embodiment is implemented as follows: This application provides a channel conduction testing device, including: an input distribution layer, a phase shifting circuit, an attenuation circuit, and an output combining layer; The input allocation layer is used to receive M input signals and divide each of the M input signals into M first branch signals. The phase-shifting circuit is used to perform phase adjustment processing on a target branch signal in one of the M first branch signals corresponding to each input signal to obtain an adjustment signal; The attenuation circuit is used to attenuate the M-1 first branch signals other than the target branch signal in the M first branch signals corresponding to each input signal to obtain an attenuated signal. The output synthesis layer is used to synthesize the adjustment signal corresponding to each input signal and the M-1 attenuation signals to obtain M output signals.

[0006] This application provides a channel conduction testing method, which is implemented based on the channel conduction testing equipment described in this application. The method includes: Receive M input signals and divide each of the M input signals into M first branch signals; A phase adjustment signal is obtained by performing phase adjustment processing on one of the target branch signals in the M first branch signals corresponding to each input signal; The M-1 first branch signals other than the target branch signal in the M first branch signals corresponding to each input signal are attenuated to obtain an attenuated signal; The adjustment signal corresponding to each input signal and the attenuation signal of M-1 channels are combined to obtain M output signals.

[0007] This application embodiment provides a control device, the control device comprising: Memory is used to store executable instructions or computer programs. The processor is configured to execute computer-executable instructions or computer programs stored in the memory to control the signal source to apply input signals to the channel conduction test device described in the embodiments of this application, adjust the parameters of the channel conduction test device, and read the output signals of the channel conduction test device, so as to implement the channel conduction test method described in the embodiments of this application.

[0008] This application provides a computer-readable storage medium storing computer-executable instructions or computer programs, which, when executed by a processor, implement the channel conduction testing method provided in this application.

[0009] This application provides a computer program product, including a computer program or computer executable instructions. When the computer program or computer executable instructions are executed by a processor, they implement the channel conduction testing method provided in this application.

[0010] The embodiments of this application have the following beneficial effects: By dividing each input signal into M first branch signals, and performing phase adjustment processing on one target branch signal in the M first branch signals corresponding to each input signal, and attenuating processing on the remaining M-1 first branch signals before synthesis, it is possible to apply controllable phase changes to specific branch signals while constructing an M×M conducted signal branch structure, and to compensate for the insertion loss differences between different branch links. This allows for the modification of the correlation characteristics between output signals while maintaining the basic consistency of the amplitude of each branch signal, thereby achieving the regulation of MIMO channel correlation, while reducing the number of phase adjustment devices and the complexity of device implementation. Attached Figure Description

[0011] Figure 1 This is a schematic diagram illustrating the application of the communication channel of the MIMO M×M communication system provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the MIMO 4×4 analog domain channel conduction test device provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the MIMO 8×8 analog domain channel conduction test equipment provided in the embodiments of this application; Figure 4 This is a schematic diagram of the connection relationship of the power divider of the MIMO 4×4 analog domain channel conduction test equipment provided in the embodiments of this application; Figure 5 This is a curve showing the relationship between the condition number CN and the phase φ of the diagonal elements in a MIMO 4×4 communication system provided in this application embodiment; Figure 6 This is a curve showing the relationship between the condition number CN and the phase of the phase shifter in a MIMO 4×4 communication system provided in this application embodiment; Figure 7 This is a schematic diagram of the structure of the integrated MIMO 4×4 analog domain channel conduction test device provided in the embodiments of this application; Figure 8 This is the relationship curve between the condition number CN and the phase φ of the diagonal element of the integrated MIMO 4×4 analog domain channel conduction test device provided in this application embodiment; Figure 9 This is a schematic diagram of the printed circuit board layout of the MIMO 4×4 analog domain channel conduction test equipment provided in the embodiments of this application; Figure 10 This is a schematic diagram of the single-layer layout of the printed circuit board of the MIMO 4×4 analog domain channel conduction test equipment provided in the embodiments of this application; Figure 11 This is a schematic diagram of the printed circuit board layout of the MIMO 8×8 analog domain channel conduction test equipment provided in the embodiments of this application; Figure 12This is a schematic diagram of the single-layer layout of the printed circuit board of the MIMO 8×8 analog domain channel conduction test equipment provided in the embodiments of this application; Figure 13 This is a flowchart illustrating the channel conduction testing method provided in the embodiments of this application. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0013] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0014] In the following description, the terms "first, second, third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0015] Unless otherwise defined, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in the embodiments of this application is for the purpose of describing the embodiments of this application only and is not intended to limit this application.

[0016] In related technologies, channel correlation, as a crucial factor influencing the quality of Multiple-Input Multiple-Output (MIMO) wireless communication, has been extensively discussed and researched in recent years in terms of evaluation criteria, testing methods, and control techniques. Past engineering experience shows that the stronger the channel correlation, the more ill-conditioned the channel response matrix becomes. This means the channel response matrix is ​​extremely sensitive to input disturbances in numerical calculations, leading to unstable results and significantly amplified errors when solving linear equations or performing matrix operations. Consequently, the worse the MIMO communication quality, the lower the throughput.

[0017] Channel correlation in wireless communication can be determined by testing the correlation coefficient between pairs of MIMO antennas, or by calculating it from channel state information extracted during MIMO communication testing. Testing MIMO performance in wireless devices is simple, but factors such as antenna pattern performance, spatial environmental obstructions, and electromagnetic interference often cause multi-parameter changes during testing. While testing the correlation between MIMO antennas and calculating channel correlation using channel state information from device communication, related technologies still have limitations in analyzing the impact of channel correlation on communication equipment: MIMO channel correlation analysis is always performed under specific scenarios; the relative positions of MIMO transceivers and antenna performance all affect channel correlation. To compare the performance of different devices under the same level of channel correlation, many communication scenarios must be constructed for comparative testing. Adjusting the relative positions of antennas to regulate channel correlation inevitably introduces signal strength fluctuations during the experiment, making it difficult to control variables and study the impact of correlation on communication quality individually. In real-world scenarios, testing channel correlation requires maintaining a consistent test environment, eliminating electromagnetic interference, and ensuring that the relative positions and antenna performance of transceivers are identical to guarantee test consistency, making experimental reproduction extremely difficult. Wireless channel simulators can set channel characteristics according to the needs of communication scenarios. However, current wireless channel simulators basically extract channel characteristics based on communication protocol requirements or customer-specific scenarios, modify the input signal, and then output it to the device under test for communication testing to achieve channel simulation. Currently, there is a lack of wireless channel simulators that design independent channel scenarios for channel correlation, making it difficult to quantitatively analyze the impact of correlation on MIMO communication. In order to simulate complex real-world communication scenarios, multiple digital domain signal processing modules are usually used, which has a high barrier to entry, is difficult to maintain, and is not conducive to integration and miniaturization design.

[0018] Channel correlation adjustment devices need to adjust the phase difference between a channel in a specific row (or column) and the phase difference between the channel elements in that row (or column) and the channel phase difference in that row (or column) from its maximum to the same value, while ensuring that the channel correlation between the channels being adjusted is very low. This achieves the change in the channel correlation of the analog conduction device from its minimum to its maximum. In order to minimize the impact on the independent channels during the adjustment process, separate phase control is required for different signal paths. Therefore, a large number of phase shifters are usually required, which is complex and costly. When adjusting the channel phase, it is difficult to avoid channel correlation between the adjusted row (or column) and other fixed rows (or columns), which limits the device's control range, makes it difficult to control the accuracy, and greatly limits its application.

[0019] To address the problems existing in related technologies, embodiments of this application provide a channel conduction testing method, a channel conduction testing device, a control device, a computer-readable storage medium, and a computer program product, which can achieve controllable adjustment of the correlation of the output signal while reducing hardware complexity. The exemplary application of the channel conduction testing device provided in the embodiments of this application is described below.

[0020] See Figure 1 , Figure 1 This is a schematic diagram of the application of the communication channel of the MIMO M×M communication system provided in the embodiments of this application. M is a positive integer greater than or equal to 2. This is a schematic diagram of a simulated channel transmission in a conducted test topology. The conducted test system 100 includes a test device 101, a device under test 102, and a channel matrix 103 disposed between the test device 101 and the device under test 102.

[0021] The test device 101 is used to output M transmit signals (input signals of the channel conduction test device), and the M transmit signals correspond to M transmit ports Tx1 to TxM respectively. The device under test 102 is used to receive M receive signals (output signals of the channel conduction test device), and the M receive signals correspond to M receive ports Rx1 to RxM respectively.

[0022] Channel matrix 103 is used to simulate the MIMO conduction channel between the device under test 101 and the device under test 102. Channel matrix 103 includes M×M signal transmission channels between M transmit ports Tx1 to TxM and M receive ports Rx1 to RxM, with each signal transmission channel corresponding to a channel coefficient. ,in, This represents a conducted analog channel between the j-th transmit port Txj and the i-th receive port Rxi.

[0023] Specifically, each transmitting port Tx is connected to each receiving port Rx, so that each transmitted signal can be transmitted to any one of the M receiving ports; each receiving port Rx is used to aggregate the signal components from the M transmitting ports Tx. Thus, the channel matrix 103 constitutes an M×M multiple-input multiple-output conducted test topology, used to characterize the signal coupling relationship and channel response relationship between the device under test 101 and the device under test 102.

[0024] In some implementations, the channel matrix 103 includes a power divider, a combiner, a phase shifter, an attenuator, and radio frequency (RF) connections. The RF connections are used to connect each device to adjust the amplitude and phase of each conducted analog channel, thereby controlling the overall channel correlation.

[0025] The channel conduction testing device provided in this application includes an input distribution layer, a phase shifting circuit, an attenuation circuit, and an output combining layer. The input distribution layer, phase shifting circuit, attenuation circuit, and output combining layer are connected sequentially via radio frequency connection lines.

[0026] The input distribution layer is used to receive M input signals and divide each of the M input signals into M first branch signals.

[0027] For example, the input distribution layer includes a power divider connected to the transmitter (test equipment). The power divider is used to distribute each input signal equally to form M first branch signals, each of which is of equal amplitude.

[0028] The phase-shifting circuit is used to perform phase adjustment processing on one of the target branch signals in the M first branch signals corresponding to each input signal to obtain the adjustment signal.

[0029] For example, the phase shifting circuit includes multiple phase shifters. The phase shifter control board integrates the phase shifter chip and control circuit. The phase shifter phase is adjusted by adjusting the switch or by inputting control commands to the microcontroller, thereby controlling the channel correlation of the entire channel conduction test equipment.

[0030] The attenuation circuit is used to attenuate the M-1 first branch signals (excluding the target branch signal) of the M first branch signals corresponding to each input signal to obtain an attenuated signal.

[0031] For example, the attenuation circuit includes multiple attenuators. The attenuation process is performed on channels that have not undergone phase shifting. That is, the attenuators adjust the link attenuation on channel links without added phase shifters to achieve consistent attenuation across all channel links.

[0032] The output synthesis layer is used to synthesize the adjustment signal corresponding to each input signal and the M-1 attenuation signals to obtain M output signals.

[0033] For example, the output combining layer includes multiple combiners connected to the receiver (device under test) receiving port, combining the power transmitted from different transmitting ports and outputting it to the receiver. Combiners are used to concentrate signals from different paths and branches onto a single port.

[0034] In this embodiment, by keeping the magnitudes of matrix elements constant and adjusting the phase difference between diagonal and off-diagonal elements, a channel response matrix with controllable singular values ​​is constructed, thereby achieving channel correlation coefficient regulation in the MIMO communication system. A channel conduction testing device in the analog domain is implemented using a combination of conduction elements. Applying the channel conduction testing device provided in this embodiment to test communication equipment can more efficiently obtain assessment results of the impact of different degrees of channel correlation on communication quality.

[0035] In some embodiments, the input distribution layer includes M power dividers, and the output combining layer includes M combiners. The M combiners and the M power dividers form M×M channels, with each combiner corresponding to M channels and each power divider corresponding to M channels. The power dividers are used to receive the input signal from the transmitter's transmit port and divide the input signal into M first branch signals. The combiners are used to combine the adjustment signal and M-1 attenuation signals into an output signal and send the output signal to the receiver's receive port.

[0036] For example, a power divider could be a split power divider. Each device in the channel link is connected via an RF coaxial cable.

[0037] See Figure 2 , Figure 2 This is a schematic diagram of the structure of the MIMO 4×4 analog domain channel conduction test device provided in this application embodiment; 4×4 channels are formed between 4 combiners and 4 power dividers. Each combiner corresponds to 4 channels, and each power divider corresponds to 4 channels; the power divider is used to receive the input signal from the transmitter's transmit port and divide the input signal into 4 first branch signals; the combiner is used to combine the adjustment signal and 3 attenuation signals into an output signal and send the output signal to the receiver's receive port.

[0038] See Figure 3 , Figure 3 This is a schematic diagram of the structure of the MIMO 8×8 analog domain channel conduction test device provided in this application embodiment; 8 combiners and 8 power dividers form 8×8 channels. Each combiner corresponds to 8 channels, and each power divider corresponds to 8 channels; the power divider is used to receive the input signal from the transmitter's transmit port and divide the input signal into 8 first branch signals; the combiner is used to combine 1 adjustment signal and 7 attenuation signals into an output signal and send the output signal to the receiver's receive port.

[0039] See Figure 4 , Figure 4 This is a schematic diagram of the connection relationship of the power divider of the MIMO 4×4 analog domain channel conduction test equipment provided in this application embodiment; the signals of the 4 transmit ports are divided into 4 paths by a 1 to 4 power divider and sent to the 4 receive ports for convergence, thereby forming a total of 16 4×4 conducted analog channels.

[0040] In some embodiments, the phase shifting circuit includes M phase shifters, each of which is disposed in a channel between a different transmit port and a receive port; the attenuation circuit includes M×(M-1) attenuators, each of which is disposed in a channel without a phase shifter, and the power attenuation of the first branch signal by the attenuator is equal to the insertion loss of the phase shifter.

[0041] For example, a phase shifter controls the phase of M non-overlapping channels between the transmit and receive ports, such as the phase of the channel elements on the diagonal of the channel response matrix. This adjusts the phase of these specific channels, thereby regulating the channel correlation of the entire analog domain conducted communication device. To keep the channel coefficient amplitude of each virtual communication channel constant, or to keep the insertion loss of each virtual communication channel the same, an attenuator with the same insertion loss as the phase shifter needs to be connected to the channel link without the phase shifter. The attenuator has a power attenuation effect. Assuming the typical insertion loss of the phase shifter chip in 5G is 5.5dB, the attenuator also applies a 5.5dB attenuation to the channel link.

[0042] In some embodiments, a channel equipped with a phase shifter includes a power divider, a transmission line, a phase shifter, and a combiner, wherein each channel equipped with a phase shifter has an electrical length of equal length.

[0043] For example, to ensure consistent phase adjustment of the condition number (CN) across different frequency bands, the channel conducted test equipment is designed with equal electrical lengths from the transmitter port through each power divider, transmission line, phase shifter, and combiner forming a virtual channel. The transmission line is also known as an RF coaxial cable.

[0044] In some embodiments, a phase shifter is disposed in a preset channel corresponding to the diagonal channel element of the channel response matrix in an M×M channel, and the phase shifter is used to change the channel correlation of the M×M channels by adjusting the phase of the signal in the preset channel.

[0045] For example, the off-diagonal channel phase remains unchanged, while the diagonal channel phase shifts traverse 0~360° to adjust the system's channel correlation. When the diagonal and off-diagonal channels have the same phase, the CN (Chemical Interference Scale) is larger. The phase shifter can be any adjustable phase shifter device. For example: a phase shifter chip can be used for convenient automated control and testing; a continuously adjustable mechanical phase shifter can be used for convenient continuous phase adjustment to achieve higher precision correlation control; an onboard RC phase shifter circuit can be used to reduce cost.

[0046] When the diagonal and off-diagonal channels are in phase, the larger the CN (conversion coefficient) is. If the number of power dividers M is greater than or equal to 4, the smaller the CN for inverted channels. Assume the off-diagonal channel phase is... When M=2, the diagonal phase corresponding to the minimum CN value is: and When M=3, the diagonal phase is at its minimum when CN is at its minimum. and .

[0047] In summary, when the diagonal and off-diagonal channels are in phase, the larger the CN value, the smaller the diagonal phase corresponding to the minimum CN value. Place.

[0048] Compared with related technologies, the channel conduction testing equipment provided in this application has the following advantages: (1) Simple structure: Traditional channel simulators focus on reproducing the signal performance in the real-world scenario in the digital domain. They not only simulate the antenna array performance of transmitting and receiving equipment through modules, but also use multiple components such as digital-to-analog converters and baseband processors to implement signal fading, multipath delay, and combining in the digital domain. The simulation content is extensive and complex. The simulated channel conduction test device proposed in this application uses a combination of power dividers, combiners, attenuators, and a small number of phase shifter components to simulate the conducted channel. The overall channel correlation of the channel conduction test device is controlled by adjusting the phase of the diagonal virtual channel. It has fewer components and is easy to implement.

[0049] (2) Low cost: Wireless channel emulators are expensive, mainly due to the various digital-to-analog converters, baseband processors, and other signal processing hardware inside the device, as well as the software configuration service for extracting channel characteristics according to protocol requirements or actual channel environment. The circuit in the embodiment of this application is implemented using only a power divider, RF connection lines, attenuators, and phase shifter chips, resulting in fewer components and lower cost. The integrated design integrates the power divider and RF connection lines on the printed circuit board, which can further reduce the cost.

[0050] (3) High control efficiency: The channel conduction test equipment proposed in this application only needs to synchronously adjust the phase of the phase shifter from small to large to achieve independent control of the channel correlation of the channel conduction test equipment. The channel conduction test equipment can test the communication performance of MIMO communication system under different correlations by connecting the transmitter and receiver at both ends. The operation is very simple and the threshold for use is low. Traditional channel simulators focus on reproducing the actual communication scenario. When using them, it is necessary to take into account the simulation of antenna array performance and the configuration of communication signal mode. The configuration items are numerous and cumbersome, and errors are easy to occur. Wireless terminal simulation equipment determines the channel correlation by the positional relationship between the actual topology test antenna and the device under test. When adjusting, a change in one part affects the whole, and it is impossible to achieve single-variable adjustment.

[0051] (4) Wide applicability: The channel conduction test equipment provided in this application embodiment can be applied to any M×M MIMO communication test, such as a 4×4 MIMO analog domain channel conduction test equipment; it is also applicable to M×N MIMO communication tests, such as MIMO 2×2, MIMO 2×3, MIMO 2×4, MIMO 3×3, MIMO 3×4 and other analog domain channel conduction test equipment. The CN minimum point of M'×N' MIMO communication in M×N corresponds to the phase. .

[0052] In some embodiments, the phase of M channels with non-overlapping transceiver ports can be synchronously adjusted while the phase of other channels remains unchanged, thereby achieving correlation adjustment of the channel conduction test equipment; or the phase of M channels with non-overlapping transceiver ports can be kept unchanged while the phase of other channels is synchronously adjusted, which can also achieve correlation adjustment of the channel conduction test equipment.

[0053] In some embodiments, the channel conduction test equipment provided in this application can be integrated into an integrated channel conduction test equipment, with the separate power divider, transmission line and phase shifter control board being implemented on the same printed circuit board (PCB), and the power divider and transmission link are arranged symmetrically to make the length of each virtual channel link as similar as possible.

[0054] See Figure 7 , Figure 7 This is a schematic diagram of the integrated MIMO 4×4 analog domain channel conduction test equipment provided in this application embodiment. For the 4×4 channel conduction test equipment, a mirrored arrangement of power dividers is used, which controls the 16 channels to be of equal length while saving layout space. By symmetrically arranging power dividers on both sides of the printed circuit board, and using vias to converge the traces on both sides of the printed circuit board to the central area of ​​the same side for output, the channel conduction test equipment is integrated.

[0055] In some embodiments, the power divider connecting the transmitter is designed on one side of the printed circuit board, and the combiner connecting the receiver is designed on the other side of the printed circuit board. All traces between the combiner and the power divider are replaced with RF through-hole traces. See [link to documentation]. Figure 9 , Figure 9 This is a schematic diagram of the printed circuit board layout of the MIMO 4×4 analog domain channel conduction test equipment provided in the embodiments of this application; this layout method solves the problems of difficult design of equal-length equipment traces and complex arrangement of high-specification MIMO communication channel conduction test equipment.

[0056] In some embodiments, channel conduction testing equipment is integrated by orthogonally tiling power dividers on both sides of a printed circuit board with appropriate spacing, and replacing the RF connection lines connecting the power dividers at the receiver and transmitter ports with vias on the printed circuit board. See also Figure 10 , Figure 10 This is a schematic diagram of the single-layer layout of the printed circuit board of the MIMO 4×4 analog domain channel conduction test equipment provided in the embodiments of this application; Figure 10 In Figures (a) and (b), the Top layer and Bot layer are set respectively.

[0057] Similarly, see Figure 11 , Figure 11 This is a schematic diagram of the printed circuit board layout of the MIMO 8×8 analog domain channel conduction test equipment provided in this application embodiment; see also Figure 12 , Figure 12 This is a schematic diagram of the single-layer layout of the printed circuit board of the MIMO 8×8 analog domain channel conduction test equipment provided in the embodiments of this application; Figure 12 In (a) and (b), the Top layer and Bot layer are set respectively.

[0058] The channel conduction test equipment provided in this application has fewer components and a smaller size. By connecting transceiver devices to both ends of the test equipment, a miniaturized MIMO communication correlation test topology can be realized, facilitating the testing of communication quality under different correlation levels. Traditional channel simulators are large and have limited flexibility during testing. The port is expandable, constructed using independent power dividers, RF connection lines, attenuators, and phase shifters, allowing for easy expansion of the number of ports according to actual testing needs. By selecting M channels with non-overlapping transceiver ports and adjusting their phases within the channel conduction test equipment, channel correlation adjustment of any M×M MIMO communication system can be achieved, testing the communication quality of the system under different channel correlations when transmitting M-modulated data streams.

[0059] In some embodiments, this application also provides a channel conduction testing method, see [link to relevant documentation]. Figure 13 , Figure 13 This is a schematic flowchart of the channel conduction testing method provided in the embodiments of this application. The channel conduction testing method is implemented based on the channel conduction testing equipment of the embodiments of this application, and is described in detail below.

[0060] In step 131, M input signals are received, and each of the M input signals is divided into M first branch signals.

[0061] In step 132, phase adjustment processing is performed on one of the target branch signals of the M first branch signals corresponding to each input signal to obtain the adjustment signal.

[0062] In some embodiments, step 132 is implemented by taking the first branch signal of the i-th input signal as the target branch signal; performing phase adjustment processing on each target branch signal to obtain an adjustment signal.

[0063] In some embodiments, the condition number of the communication channel capacity is obtained by: analyzing the M output signals to obtain the channel response matrix; multiplying the channel response matrix by its conjugate transpose to obtain the channel Hermitian matrix; performing eigenvalue decomposition on the channel Hermitian matrix to obtain M real eigenvalues; selecting the largest and smallest eigenvalues ​​from the M real eigenvalues; and calculating the condition number characterizing the channel correlation based on the ratio of the largest to the smallest eigenvalue.

[0064] The channel response matrix H includes the transmission channel coefficients between the transmitting and receiving antennas. In the conducted simulation topology, the signal is transmitted through the radio frequency traces, satisfying the narrowband flat fading channel assumption. The transmission channel coefficients are time-based functions. Fading channels are the phenomenon in wireless communication where the amplitude of the received signal changes randomly due to channel variations. Under the narrowband flat fading channel assumption, the channel coefficients can be considered to have flat amplitudes, fixed phases, and remain constant. The channel response matrix can be expressed as the following formula (1): (1) It is the channel response matrix; This refers to the number of receive ports; It refers to the number of transmission ports; It is the channel response matrix The Middle Line 1 The channel coefficients of the column represent the first column. The first transmission port to the first Complex channel responses between multiple receiving ports; It is the receive port index, and ; It is the transmit port index, and ; It is the channel coefficient between the first transmit port and the first receive port; and so on. It is the channel coefficient between the second transmit port and the first receive port; It is the first The channel coefficient between the first transmit port and the first receive port; It is the channel coefficient between the first transmitting port and the second receiving port; It is the channel coefficient between the second transmit port and the second receive port; It is the first The channel coefficient between the first transmit port and the second receive port; It is from the first transmission port to the... Channel coefficients between each receiving port; It is the second transmission port to the... Channel coefficients between each receiving port; It is the first The first transmission port to the first Channel coefficients between each receiving port; Channel coefficient The amplitude; Channel coefficient The phase; It is with phase The corresponding complex exponential term; Channel coefficient amplitude, Channel coefficient The phase; Channel coefficient amplitude, Channel coefficient The phase; Channel coefficient amplitude, Channel coefficient The phase; Channel coefficient amplitude, Channel coefficient The phase; Channel coefficient amplitude, Channel coefficient The phase; Channel coefficient amplitude, Channel coefficient The phase; Channel coefficient amplitude, Channel coefficient The phase; Channel coefficient amplitude, Channel coefficient The phase; Channel coefficient amplitude, Channel coefficient The phase; It is a natural constant; In complex terms The middle is the imaginary unit, which satisfies .

[0065] Formula (1) represents the channel response matrix. Each channel coefficient in All can be expressed as the corresponding amplitude. With corresponding phase The resulting polar coordinate form. Communication systems typically use the channel response matrix. H Calculated autocorrelation matrix R Examine channel correlation. The autocorrelation matrix is ​​composed of channel autocorrelation or cross-correlation coefficients. Autocorrelation matrix of MIMO communication system R The dimension is The number of coefficients is large. Considering the channel response matrix... Its conjugate transpose product It is a Hermitian matrix. When the transmitter does not contain communication channel information and all antennas have the same transmission power, the Hermitian matrix... eigenvalues Used to characterize the effective transmission power gain of the channel for each data stream. The rank of the matrix... R It represents the number of non-zero eigenvalues, that is, the number of different data streams transmitted through the channel. When considering... When the communication system transmits its highest data stream, that is... When full rank, the number of non-zero eigenvalues R equal and The smaller value in, based on Calculate the condition number CN.

[0066] The condition number CN is the ratio of the largest singular value to the smallest singular value of a matrix. Singular Value Decomposition (SVD) is a concept in linear algebra that decomposes a matrix into the product of three matrices. For a 4x4 square matrix... Its singular value decomposition can be expressed as: ,in, It is orthogonal matrix (i.e. ). It is A diagonal matrix whose diagonal elements are singular values ,and . It is orthogonal matrix (i.e. Singular values By calculating the matrix The singular values ​​are obtained from the eigenvalues ​​of the matrix. Specifically, singular values ​​are the eigenvalues ​​of the matrix. or The square root of the eigenvalues. Assume... eigenvalues So, singular values It can be represented as: , yes eigenvalues.

[0067] Example, calculation The steps for calculating singular values ​​are as follows: This can be expressed as the following formula (2.1): (2.1) Example, The Line 1 The column elements can be uniformly written as the following formula (2.2): (2.2) Solve eigenvalues And calculate singular values. This is achieved by: processing the matrix Construct the characteristic equation The matrix is ​​obtained by solving the characteristic equation. eigenvalues Furthermore, a matrix is ​​obtained based on the eigenvalues. The singular values ​​are determined, and the condition number CN is calculated based on the maximum and minimum singular values. The characteristic equation is constructed as follows (2.3): (2.3) Represents a determinant; It is an eigenvalue variable; It is a 4th order identity matrix, represented as ,Will After substituting, we get the following formula (2.4): (2.4) Expanding the above determinant, we can obtain the following about The quartic characteristic polynomial (2.5): (2.5) Solving for the four roots of the quartic equation yields the eigenvalues: Among the four eigenvalues Maximum eigenvalue With the smallest eigenvalue of the matrix The ratio can be used to characterize transmission. R The ratio of the maximum effective transmission power gain to the minimum effective transmission power gain in a data stream.

[0068] When strong channel correlation occurs in the transmission channel, the effective power of at least one data stream will decrease. At this time, the transmission quality of this data stream will decrease, the communication throughput will decrease, and the condition number CN of the channel response matrix will increase due to the decrease in the denominator (minimum effective transmission power gain). The larger the condition number CN value, the more ill-conditioned the channel matrix, the stronger the channel correlation, the worse the MIMO communication quality, and the lower the throughput. Since the condition number CN quantifies the impact of channel correlation on MIMO communication transmission, the condition number CN can be used as an indicator to measure the channel correlation of the MIMO communication system, as expressed by the following formula (3).

[0069] (3) As the number of transceiver ports increases and the specifications of MIMO communication systems become more sophisticated, the method of adjusting the channel correlation of the entire communication system by constructing a channel matrix with correlation between the channel coefficients of two rows (or columns) becomes complex. In this embodiment, M channel matrix elements are selected from an M×M channel matrix with identical amplitudes, and their phases are synchronously adjusted to achieve channel correlation adjustment of the communication system. The row and column numbers of the M channel matrix elements are all different.

[0070] For example, in a MIMO 4×4 communication system, all channel coefficients are kept at an amplitude of 1, the phase of off-diagonal elements is kept at 0°, and the phase of diagonal elements is adjusted from 0 to 360°. The channel matrix format is as shown in formula (4).

[0071] (4) Based on the channel matrix in formula (4) and the principles of formulas (1) to (3) above, calculate the channel matrix condition number CN corresponding to the phase of different diagonal elements.

[0072] In step 133, the M-1 first branch signals other than the target branch signal in the M first branch signals corresponding to each input signal are attenuated to obtain attenuated signals.

[0073] In step 134, the adjustment signal corresponding to each input signal and the M-1 attenuation signals are synthesized to obtain M output signals.

[0074] See Figure 5 , Figure 5 This is a curve showing the relationship between the condition number CN and the phase φ of the diagonal elements in a MIMO 4×4 communication system provided in this application embodiment; the condition number CN value changes from infinity to 0 and then back to infinity as the phase φ changes. By selecting an appropriate phase φ adjustment precision, precise adjustment of the correlation of the corresponding communication system can be obtained. The channel coefficients selected for adjusting the phase are respectively... , , and The row and column numbers of the four channel coefficients are all different. According to design theory, there are also various methods for selecting channel coefficients to control the phase, such as... , , and The channel conduction testing method provided in this application can also be extended to control channel correlation in other MIMO M×M communication systems.

[0075] See Figure 6 , Figure 6This is a curve showing the relationship between the condition number (CN) and the phase of the phase shifter in a MIMO 4×4 communication system provided in this application embodiment. When using the channel conduction test equipment, the four phase shifters need to be set to the same phase. Adjusting the phase of the phase shifter from 0° to 360° can adjust the CN value of the channel conduction test equipment. Since the initial phase difference between the channel link connected to the phase shifter and the channel link not connected to the phase shifter is not 0, the highest value of the CN value curve of the channel conduction test equipment as the phase shifter changes from 0° to 360° may deviate from the 0° phase point. Furthermore, the channel conduction test equipment is composed of separate RF coaxial cables, power dividers, and phase shifter control boards. It is difficult to control the electrical length of the diagonal channel link that needs to be connected to the phase shifter control board and the RF coaxial cables of other non-diagonal channels to be equal, resulting in different degrees of deviation of the CN value adjustment curve from the 0° point at different frequency points. In other words, the CN value adjustment effect of the channel conduction test equipment is different at different frequency points.

[0076] See Figure 8 , Figure 8 This application provides an embodiment of the integrated MIMO 4×4 analog domain channel conduction test equipment, showing the relationship between the condition number CN and the phase φ of the diagonal elements. For the integrated channel conduction test equipment, the transmission coefficients were simulated using full-wave simulation software, confirming that the attenuation of each link is comparable and the phase difference is less than 10°. The relationship between the condition number CN of the channel response matrix and the phase setting of the phase shifter for the integrated analog domain channel conduction test equipment with adjustable channel correlation is shown below. Figure 8 It can be seen that the CN value of the channel conduction test equipment can vary from 1.1dB to more than 35dB as the phase shifter is adjusted, and the difference between the CN value curves of different frequency points and the phase change curves of the phase shifter is also greatly reduced.

[0077] This application embodiment provides a control device, the control device comprising: Memory is used to store executable instructions or computer programs. The processor is configured to execute computer-executable instructions or computer programs stored in the memory to control the signal source to apply input signals to the channel conduction test device described in the embodiments of this application, adjust the parameters of the channel conduction test device, and read the output signals of the channel conduction test device, so as to implement the channel conduction test method described in the embodiments of this application.

[0078] This application provides a computer program product, which includes a computer program or computer-executable instructions stored in a computer-readable storage medium. The processor of an electronic device reads the computer-executable instructions from the computer-readable storage medium and executes the computer-executable instructions, causing the electronic device to perform the channel conduction testing method described above in this application.

[0079] This application provides a computer-readable storage medium storing computer-executable instructions or a computer program. When the computer-executable instructions or the computer program are executed by a processor, the processor will execute the channel conduction testing method provided in this application, for example... Figure 13 The channel conduction test method is shown.

[0080] In some embodiments, the computer-readable storage medium may be a memory such as RAM, ROM, flash memory, magnetic surface memory, optical disk, or CD-ROM; or it may be a variety of devices including one or any combination of the above-mentioned memories.

[0081] In some embodiments, computer-executable instructions may take the form of programs, software, software modules, scripts, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as stand-alone programs or as modules, components, subroutines, or other units suitable for use in a computing environment.

[0082] As an example, computer-executable instructions can be deployed to execute on a single electronic device, or on multiple electronic devices located at one location, or on multiple electronic devices distributed across multiple locations and interconnected via a communication network.

[0083] In summary, by dividing each input signal into M first branch signals, and performing phase adjustment processing on one target branch signal in the M first branch signals corresponding to each input signal, and attenuating processing on the remaining M-1 first branch signals before synthesis, it is possible to construct an M×M conducted signal branch structure while applying controllable phase changes to specific branch signals and compensating for the insertion loss differences between different branch links. This allows for the modification of the correlation characteristics between output signals while maintaining the basic consistency of the amplitude of each branch signal, thereby achieving the regulation of channel correlation in the MIMO wireless communication system, while reducing the number of phase adjustment devices and the complexity of device implementation.

[0084] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.

Claims

1. A channel conduction testing device, characterized in that, include: Input distribution layer, phase shifting circuit, attenuation circuit, and output combining layer; The input allocation layer is used to receive M input signals and divide each of the M input signals into M first branch signals. The phase-shifting circuit is used to perform phase adjustment processing on a target branch signal in one of the M first branch signals corresponding to each input signal to obtain an adjustment signal; The attenuation circuit is used to attenuate the M-1 first branch signals other than the target branch signal in the M first branch signals corresponding to each input signal to obtain an attenuated signal. The output synthesis layer is used to synthesize the adjustment signal corresponding to each input signal and the M-1 attenuation signals to obtain M output signals.

2. The device according to claim 1, characterized in that, The input distribution layer includes M power dividers, and the output combining layer includes M combiners. The M combiners and the M power dividers form M×M channels, with each combiner corresponding to M channels and each power divider corresponding to M channels. The power divider is used to receive the input signal from the transmitter's transmit port and divide the input signal into M first branch signals; The combiner is used to combine the adjustment signal and the M-1 attenuation signals into the output signal, and send the output signal to the receiving port of the receiver.

3. The device according to claim 2, characterized in that, The phase shifting circuit includes M phase shifters, each of which is disposed in a different channel between the transmitting port and the receiving port; The attenuation circuit includes M×(M-1) attenuators, each of which is located in a channel without the phase shifter, and the power attenuation of the first branch signal by the attenuator is equal to the insertion loss of the phase shifter.

4. The device according to claim 3, characterized in that, The channel equipped with the phase shifter includes: the power divider, the transmission line, the phase shifter, and the combiner, wherein the electrical lengths of each channel from each of the transmitting ports to each of the receiving ports are equal.

5. The device according to claim 3, characterized in that, The phase shifter is disposed in a preset channel corresponding to the diagonal channel element of the channel response matrix in the M×M channels. The phase shifter is used to change the channel correlation of the M×M channels by adjusting the phase of the signal in the preset channel.

6. A channel conduction testing method, characterized in that, The method is implemented based on the channel conduction test equipment according to any one of claims 1 to 5, and the method includes: Receive M input signals and divide each of the M input signals into M first branch signals; A phase adjustment signal is obtained by performing phase adjustment processing on one of the target branch signals in the M first branch signals corresponding to each input signal; The M-1 first branch signals other than the target branch signal in the M first branch signals corresponding to each input signal are attenuated to obtain an attenuated signal; The adjustment signal corresponding to each input signal and the attenuation signal of M-1 channels are combined to obtain M output signals.

7. The method according to claim 6, characterized in that, The step of performing phase adjustment processing on a target branch signal from one of the M first branch signals corresponding to each input signal to obtain an adjusted signal includes: Take the first branch signal of the i-th input signal as the target branch signal; Each target branch signal is subjected to phase adjustment processing to obtain an adjusted signal.

8. The method according to claim 6, characterized in that, The method further includes: The M output signals are analyzed to obtain the channel response matrix; Multiplying the channel response matrix by its conjugate transpose yields the channel Hermitian matrix. The channel Hermitian matrix is ​​decomposed into M real eigenvalues. Select the largest and smallest eigenvalues ​​from the M real eigenvalues; The condition number characterizing channel correlation is calculated based on the ratio of the maximum eigenvalue to the minimum eigenvalue.

9. A control device, characterized in that, The control device includes: Memory is used to store executable instructions or computer programs. A processor is configured to execute computer-executable instructions or computer programs stored in the memory to control a signal source to apply an input signal to the channel conduction test device according to any one of claims 1 to 5, adjust the parameters of the channel conduction test device, and read the output signal of the channel conduction test device, so as to implement the channel conduction test method according to any one of claims 6 to 8.

10. A computer-readable storage medium storing computer-executable instructions or a computer program, characterized in that, When the computer-executable instructions or computer program are executed by a processor, they implement the channel conduction testing method according to any one of claims 6 to 8.

Images