CN116846490A - Wireless performance measurement method and system for MIMO (multiple input multiple output) equipment - Google Patents

Abstract

The invention provides a wireless performance measurement method and a system of MIMO equipment, wherein a second antenna radiation pattern is used in the wireless performance measurement method of the MIMO equipment, namely, the antenna radiation pattern taking each receiver feed point of the MIMO equipment to be measured as a reference contains the influence of a wire harness part on wireless performance measurement, so that a multi-channel measurement emission signal generated by the second antenna radiation pattern is more accurate, and the wireless performance measurement result of the MIMO equipment to be measured based on the accurate multi-channel measurement emission signal measurement is also more accurate.

Description

Wireless performance measurement method and system for MIMO (multiple input multiple output) equipment

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method and a system for measuring wireless performance of MIMO devices.

Background

Performance measurement of MIMO (Multiple-Input Multiple-Output) devices is also becoming particularly important due to the widespread use of MIMO technology. MIMO OTA (Over-the-Air) measurement techniques overcome the limitations of conventional conductive measurement methods and are widely used for MIMO performance assessment. The MIMO OTA measurement method is mainly three types, namely a method based on a reverberation room, a method based on a radiation Two-Stage (RTS) and a method based on a Multi-probe microwave darkroom (Multi-Probe Anechoic Chamber, MPAC).

The RTS method comprises two phases: the first stage is to measure and obtain the antenna radiation pattern information of the equipment to be measured (Device Under Test, DUT, specifically MIMO equipment to be measured) in the darkroom; and the second stage loads the antenna radiation pattern information measured in the first stage into a channel simulator to simulate a wireless channel containing the antenna characteristics of the DUT, and the downlink signal output by the base station simulator is firstly convolved with the wireless channel loaded with the antenna radiation pattern information of the equipment to be measured and then is transmitted out through a measuring antenna to measure the performance of a receiver of the DUT.

In the RTS method, a signal output from a base station simulator (recorded as) With the signal received by the receiver of the DUT (recorded as +.>) The relationship between them can be expressed as:wherein [ the] ^T Representing a matrix transpose; h (t) represents a channel correlation matrix comprising the signal +.>All of the transformation information experienced throughout the process is received from the measurement antenna radiation, propagation of the spatial channels, antenna coupling to the DUT, and the receiver.

The first stage of the RTS method requires measuring the antenna radiation pattern information of the DUT. Referring to fig. 1, in making antenna radiation pattern measurements, the DUT's antenna needs to be disconnected from the receiver in order to connect the vector network analyzer (Vector Network Analyzers, VNA) to the feed point (i.e., antenna feed point) of the antenna under test (Antenna Under Test, AUT) to perform passive measurements. In the second stage of measurement, referring to fig. 2-3, in order to measure the overall radiation performance of the DUT, the disconnected connection in the first stage is required to be reconnected to place the DUT in the overall state.

The link between the antenna feed and the receiver feed is referred to as a wire harness, including but not limited to RF cables, amplifiers, and the like. Referring to fig. 1-3, antenna radiation pattern measurement is based on antenna feed points, and the inventors found that the prior art antenna radiation pattern information obtained by passive measurement does not include a beam part, whereas in the RTS method, the connection of the air interface direct connection (virtual wire) is at the receiver feed point of the DUT, i.e. corresponds to feeding the measurement signal directly from the meter output port to the receiver feed point, and if in the RTS method, the aforementioned antenna radiation pattern information not including a beam part is employed, the beam is not taken into account when performing the measurement.

In some multi-receiver wireless devices, a cable connection is used between the receiver and the antenna. Such wireless devices are often large-sized wireless devices, such as vehicles. Referring to fig. 4, in the design of a vehicle radio, antennas need to be distributed at different locations of the vehicle body, even outside the vehicle. And the receiver is usually placed in the car, even in the central control area, to ensure its stability. The use of a cable connection between the receiver and the corresponding antenna is therefore required, and also the installation fit between the cable and the vehicle body is a concern, so that different antennas may require the use of cables of different lengths, which may vary from 1m to 3m for vehicles. Cables of different lengths cause different losses, which also increase with increasing frequency. Typical radio frequency cables have losses in the V2X band of about 0.6dB/m-2dB/m, which can severely impact the communication performance of the vehicle. In addition, in order to increase the signal strength, an amplifier may be added between the antenna and the receiver in vehicle communications, such that the wire harness between the antenna feed and the receiver feed also includes an amplifier. In summary, the wire harness loss from the antenna feed to the receiver feed will not be controllable and estimated, nor will it be removable for measurement (because the receiver feed is in fact a virtual, not directly presented point, but the antenna feed is a physically removable connection point).

For the above reasons, the prior art has a technical problem of poor measurement accuracy when using the RTS method to measure the wireless performance of the MIMO device.

Disclosure of Invention

In view of the above, the present invention aims to provide a method and a system for measuring wireless performance of a MIMO device, so as to alleviate the technical problem of poor accuracy when the RTS method is used to measure wireless performance of the MIMO device in the prior art.

In a first aspect, an embodiment of the present invention provides a method for measuring wireless performance of a MIMO device, including:

acquiring a plurality of first antenna radiation patterns of the MIMO equipment to be tested, wherein the first antenna radiation patterns are antenna radiation patterns taking each antenna feed point of the MIMO equipment to be tested as a reference;

acquiring the strength indication returns of the received signals of a plurality of receivers of the MIMO equipment to be tested, and calculating the wire harness loss between the antenna feed point of each antenna and the corresponding receiver feed point based on the strength indication returns of the received signals of each receiver and the gain of the corresponding first antenna radiation pattern;

correcting the corresponding first antenna radiation patterns by adopting the harness loss to obtain a plurality of second antenna radiation patterns, wherein the second antenna radiation patterns are antenna radiation patterns taking each receiver feed point of the MIMO equipment to be tested as a reference;

and generating a plurality of transmission signals for measurement based on the radiation patterns of the second antennas, and feeding the plurality of transmission signals for measurement to the plurality of measurement antennas so as to measure the wireless performance of the MIMO device to be measured through the plurality of measurement antennas.

Further, calculating a wire harness loss between an antenna feed point and a corresponding receiver feed point for each antenna based on the strength indication return of the received signal for each of the receivers and the gain of the corresponding first antenna radiation pattern, comprising:

calculating antenna gains of the antennas based on the strength indication payback of the received signals of each receiver;

and calculating the wire harness loss between the antenna feed point and the corresponding receiver feed point of each antenna according to the antenna gain reported by the intensity indication of the received signal of each antenna and the gain of the corresponding first antenna radiation pattern.

Further, calculating an antenna gain of each antenna based on the strength indication return of the received signal of each receiver, comprising:

antenna gain calculation formula according to strength indication return based on received signalCalculating an antenna gain for each of the antennas based on a return of the strength indication of the received signal, wherein +_>Indicating the antenna gain reported based on the strength indication of the received signal at angle Ω, polarization x, RSSI for the antenna corresponding to the ith receiver _i Indicating return of strength indication of received signal of ith receiver, P _BSE Indicating the power of the signal output by the meter during active measurement, PL indicates the path loss in the measurement environment.

Further, calculating a wire harness loss between an antenna feed point and a corresponding receiver feed point of each antenna according to an antenna gain reported based on an intensity indication of a received signal and a gain of a corresponding first antenna radiation pattern of each antenna, including:

calculating according to the wire harness lossCalculating a wire harness loss between an antenna feed point and a corresponding receiver feed point of each antenna, wherein delta G _i Represents the wire harness loss between the antenna feed point of the ith antenna and the corresponding receiver feed point,/>Indicating the antenna gain reported by the i-th receiver corresponding antenna at an angle Ω, polarization x, based on the strength indication of the received signal,/v>The gain of the first antenna radiation pattern at angle q, polarization x, for the antenna corresponding to the ith receiver is shown.

Further, generating a plurality of transmission signals for measurement based on the plurality of second antenna radiation patterns includes:

loading a plurality of second antenna radiation patterns into a channel simulator to simulate a wireless channel containing the antenna characteristics of the MIMO equipment to be tested;

inputting each path of downlink signals output by the measuring instrument to the channel simulator, and convolving with the wireless channel;

and performing error elimination on the signals obtained by convolution to obtain a plurality of paths of transmitting signals for measurement.

Further, performing error cancellation on the convolved signal, including:

inputting the convolved signal to an RF module, wherein the RF module calculates the convolved signal according to an error elimination matrix to eliminate errors, and the error elimination matrix is P _mea ^-1 ＝P ^-1 ·E ^-1 ，P _mea ^-1 Representing the error cancellation matrix, P ^-1 An inverse matrix, E, representing a propagation matrix, P ^-1 Representing the inverse of the error matrix E.

In a second aspect, an embodiment of the present invention further provides a system for measuring wireless performance of a MIMO device, where the system for measuring wireless performance of a MIMO device uses the method for measuring wireless performance of a MIMO device according to any one of the first aspect to measure wireless performance of a MIMO device to be measured, and the system for measuring wireless performance of a MIMO device includes: the system comprises a measuring instrument, a channel simulator, an RF module, a measuring antenna and a communication antenna;

the measuring instrument is used for outputting a plurality of paths of downlink signals;

the channel simulator is used for simulating a wireless channel comprising the antenna characteristics of the MIMO equipment to be tested and convolving the downlink signal with the wireless channel;

the RF module is used for carrying out error elimination on the signals obtained by convolution to obtain a plurality of transmission signals for measurement, and feeding the plurality of transmission signals for measurement into a plurality of measurement antennas;

the measuring antenna is used for transmitting multiple paths of transmitting signals for measurement to the MIMO equipment to be measured, so that the MIMO equipment to be measured transmits uplink signals to the communication antenna after receiving multiple paths of transmitting signals for measurement;

and the communication antenna is used for receiving the uplink signal and sending the uplink signal to the measuring instrument so that the measuring instrument can measure the wireless performance of the MIMO equipment to be measured.

Further, the channel simulator and the RF module are integrated in the measuring instrument.

Further, the method further comprises the following steps: an upper computer;

the upper computer is connected with the measuring instrument and used for controlling the measuring instrument to work.

Further, the method further comprises the following steps: the anechoic chamber is used for providing a measuring environment;

at least the measuring antenna and the communication antenna are arranged in the anechoic chamber.

Further, the MIMO device under test includes a vehicle having a MIMO communication system.

In an embodiment of the present invention, there is provided a wireless performance measurement method of a MIMO device, including: acquiring a plurality of first antenna radiation patterns of the MIMO equipment to be tested, wherein the first antenna radiation patterns are antenna radiation patterns taking each antenna feed point of the MIMO equipment to be tested as a reference; acquiring the strength indication returns of the received signals of a plurality of receivers of the MIMO equipment to be tested, and calculating the wire harness loss between the antenna feed point of each antenna and the corresponding receiver feed point based on the strength indication returns of the received signals of each receiver and the gain of the corresponding first antenna radiation pattern; correcting the corresponding first antenna radiation patterns by using wire harness loss to obtain a plurality of second antenna radiation patterns, wherein the second antenna radiation patterns are antenna radiation patterns taking each receiver feed point of the MIMO equipment to be tested as a reference; and generating a plurality of transmission signals for measurement based on the radiation patterns of the second antennas, and feeding the transmission signals for measurement into the plurality of measurement antennas so as to measure the wireless performance of the MIMO equipment to be measured through the plurality of measurement antennas. As can be seen from the above description, in the method for measuring wireless performance of MIMO equipment according to the present invention, the second antenna radiation pattern is used, that is, the antenna radiation pattern with each receiver feed point of the MIMO equipment to be measured as a reference, which includes the influence of the wire harness portion on the measurement of wireless performance, so that the multi-channel measurement transmission signal generated by using the second antenna radiation pattern is more accurate, so that the measurement result of wireless performance of the MIMO equipment to be measured based on the accurate multi-channel measurement transmission signal measurement is also more accurate, and the technical problem of poor accuracy when the RTS method is used to measure wireless performance of the MIMO equipment in the prior art is solved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of passive antenna radiation pattern measurement of a MIMO device provided by the conventional technology;

fig. 2 is a schematic structural diagram of wireless performance measurement of a MIMO device provided by the conventional technology;

fig. 3 is a schematic diagram of a communication structure for performing wireless performance measurement of a MIMO device using an RTS method provided in the conventional art;

fig. 4 is a schematic structural diagram of a MIMO vehicle to be tested according to an embodiment of the present invention;

fig. 5 is a flowchart of a method for measuring wireless performance of MIMO equipment according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a system for measuring wireless performance of MIMO equipment according to an embodiment of the present invention.

Detailed Description

The technical solutions of the present invention will be clearly and completely described in connection with the embodiments, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the prior art, when the RTS method is used to measure the wireless performance of the MIMO device, a first antenna radiation pattern is used, that is, an antenna radiation pattern taking each antenna feed point of the MIMO device to be measured as a reference, which does not include the influence of the wire harness portion on the wireless performance measurement, so that the accuracy of the multi-path measurement transmission signal generated by using the first antenna radiation pattern is poor, and the accuracy of the finally obtained wireless performance measurement result of the MIMO device to be measured is poor.

Based on this, in the method for measuring wireless performance of MIMO device according to the present invention, the second antenna radiation pattern is used, that is, the antenna radiation pattern with each receiver feed point of the MIMO device to be measured as a reference, which includes the influence of the wire harness portion on the measurement of wireless performance, so that the multi-channel measurement transmission signal generated by using the second antenna radiation pattern is more accurate, and the measurement result of wireless performance of the MIMO device to be measured based on the accurate multi-channel measurement transmission signal measurement is also more accurate.

For the sake of understanding the present embodiment, a detailed description will be given of a method for measuring wireless performance of MIMO equipment according to the present embodiment.

Embodiment one:

according to an embodiment of the present invention, there is provided an embodiment of a wireless performance measurement method of a MIMO device, it being noted that the steps shown in the flowchart of the drawings may be performed in a computer system such as a set of computer executable instructions, and that although a logical order is shown in the flowchart, in some cases the steps shown or described may be performed in an order different from that herein.

Fig. 5 is a flowchart of a wireless performance measurement method of a MIMO device according to an embodiment of the present invention, as shown in fig. 5, the method comprising the steps of:

step S502, a plurality of first antenna radiation patterns of the MIMO equipment to be tested are obtained, wherein the first antenna radiation patterns are antenna radiation patterns taking each antenna feed point of the MIMO equipment to be tested as a reference;

specifically, referring to fig. 1, in the anechoic chamber, the connection between the antenna of the MIMO device to be tested and the corresponding receiver is disconnected, specifically, the cable connected to the corresponding receiver at the feed point of the antenna is disconnected, the vector network analyzer is respectively connected to the feed point of the antenna of the MIMO device to be tested, passive measurement is performed, and a plurality of first antenna radiation patterns are obtained by reading amplitude and phase parameters.

The first antenna radiation pattern is an antenna radiation pattern taking each antenna feed point of the MIMO device to be tested as a reference.

Step S504, obtaining the strength indication returns of the received signals of a plurality of receivers of the MIMO equipment to be tested, and calculating the wire harness loss between the antenna feed point of each antenna and the corresponding receiver feed point based on the strength indication returns of the received signals of each receiver and the gain of the corresponding first antenna radiation pattern;

specifically, active measurement is performed on the MIMO device to be measured, even if the antenna feed point of the MIMO device to be measured is connected to the cable between the corresponding receiver and the cable, the measuring antenna sends signals to the MIMO device to be measured, and the strength indication (Received Signal Strength Indication, RSSI) return of the received signals of the multiple receivers of the MIMO device to be measured is obtained, so that the wire harness loss between the antenna feed point of each antenna and the corresponding receiver feed point (i.e., the receiver feed point connected to the antenna feed point by using the same wire harness) is calculated based on the strength indication return of the received signals of each receiver and the gain of the corresponding first antenna radiation pattern, and the process of calculating the wire harness loss is described in detail herein.

Step S506, correcting the corresponding first antenna radiation patterns by using the wire harness loss to obtain a plurality of second antenna radiation patterns, wherein the second antenna radiation patterns are antenna radiation patterns taking each receiver feed point of the MIMO equipment to be tested as a reference;

specifically, ΔG _i Represents the harness loss of the ith antenna by Δg _i Correcting the radiation pattern of the first antenna of the ith antenna to obtain the radiation pattern of the second antenna of the ith antenna, which is expressed as

Thereby the processing time of the product is reduced,is equal to the antenna gain derived from the RSSI measurement (i.e. the active measurement in the present invention) at the receiver feed point, and furthermore,/is>Phase information is also included. It should be noted that the wireless performance measurement of the MIMO device requires complete pattern information (i.e. it needs to include amplitude and phase information), and therefore, the wireless performance measurement of the MIMO device cannot be performed directly using the pattern obtained by the RSSI measurement (i.e. active measurement) (because only gain/amplitude information is used), and some wireless devices can report the phase in addition to the power, but the relative phase rather than the absolute phase is reported, and furthermore, many wireless devices do not have a function of reporting the phase, so we only use the reported power, i.e. RSSI).

Step S508, generating a plurality of transmission signals for measurement based on the plurality of second antenna radiation patterns, and feeding the plurality of transmission signals for measurement to the plurality of measurement antennas to measure the wireless performance of the MIMO device to be measured through the plurality of measurement antennas.

Hereinafter, the process of generating the transmission signals for multi-channel measurement will be described in detail, and will not be described in detail.

After the multi-path measurement emission signals are obtained, the multi-path measurement emission signals are fed into a plurality of measurement antennas, the plurality of measurement antennas emit measurement emission signals, the MIMO equipment to be measured receives the measurement emission signals, and then the MIMO equipment to be measured sends uplink signals, receives the uplink signals through the communication antennas and sends the uplink signals to the measurement instrument, so that the wireless performance measurement of the MIMO equipment to be measured is realized.

In an embodiment of the present invention, there is provided a wireless performance measurement method of a MIMO device, including: acquiring a plurality of first antenna radiation patterns of the MIMO equipment to be tested, wherein the first antenna radiation patterns are antenna radiation patterns taking each antenna feed point of the MIMO equipment to be tested as a reference; acquiring the strength indication returns of the received signals of a plurality of receivers of the MIMO equipment to be tested, and calculating the wire harness loss between the antenna feed point of each antenna and the corresponding receiver feed point based on the strength indication returns of the received signals of each receiver and the gain of the corresponding first antenna radiation pattern; correcting the corresponding first antenna radiation patterns by using wire harness loss to obtain a plurality of second antenna radiation patterns, wherein the second antenna radiation patterns are antenna radiation patterns taking each receiver feed point of the MIMO equipment to be tested as a reference; and generating a plurality of transmission signals for measurement based on the radiation patterns of the second antennas, and feeding the transmission signals for measurement into the plurality of measurement antennas so as to measure the wireless performance of the MIMO equipment to be measured through the plurality of measurement antennas. As can be seen from the above description, in the method for measuring wireless performance of MIMO equipment according to the present invention, the second antenna radiation pattern is used, that is, the antenna radiation pattern with each receiver feed point of the MIMO equipment to be measured as a reference, which includes the influence of the wire harness portion on the measurement of wireless performance, so that the multi-channel measurement transmission signal generated by using the second antenna radiation pattern is more accurate, so that the measurement result of wireless performance of the MIMO equipment to be measured based on the accurate multi-channel measurement transmission signal measurement is also more accurate, and the technical problem of poor accuracy when the RTS method is used to measure wireless performance of the MIMO equipment in the prior art is solved.

The above-mentioned contents briefly describe a wireless performance measurement method of the MIMO device of the present invention, and detailed descriptions will be given below with respect to the specific contents.

In an alternative embodiment of the present invention, the method for calculating the wire harness loss between the antenna feed point and the corresponding receiver feed point of each antenna based on the strength indication return of the received signal of each receiver and the gain of the corresponding first antenna radiation pattern specifically includes the following steps:

(1) Calculating an antenna gain of each antenna based on the strength indication return of the received signal of each receiver;

the specific process is as follows:

antenna gain calculation formula according to strength indication return based on received signalCalculating antenna gain of each antenna based on strength indication return of received signal, wherein +_>Indicating the antenna gain reported based on the strength indication of the received signal at angle Ω, polarization x, RSSI for the antenna corresponding to the ith receiver _i Indicating return of strength indication of received signal of ith receiver, P _BSE Indicating the power of the signal output by the meter during active measurement, PL indicates the path loss (including links, amplifiers, cables, space losses, etc., available) in the measurement environment.

Specifically, subtracting the downlink power value reaching the front end of the MIMO device to be tested from the strength indication report of the received signal of the receiver can obtain the antenna gain (which can be regarded as the gain of the second antenna radiation pattern but contains the error introduced by the RSSI measurement) of the antenna based on the strength indication report of the received signal, and the calculation formula is as follows (in dB):

wherein,,indicating the antenna gain reported based on the strength indication of the received signal at angle Ω, polarization x, RSSI for the antenna corresponding to the ith receiver _i Indicating return of strength indication of received signal of ith receiver, P _BSE Representing the power of the signal output by the meter during active measurement, PL representing the path loss (including link, amplifier, cable, space loss, etc. available) in the measurement environment, P _BSE PL represents the downlink power value to the front end of the MIMO device under test.

The measuring instrument may be a base station or a base station simulator, or may be a comprehensive tester (comprehensive tester), and the channel simulator and the RF module may be separate instruments, or may be integrated into the comprehensive tester, where the measuring instrument is not specifically limited.

(2) And calculating the wire harness loss between the antenna feed point and the corresponding receiver feed point of each antenna according to the antenna gain of each antenna based on the strength indication return of the received signals and the gain of the corresponding first antenna radiation pattern.

The specific process is as follows:

calculating according to the wire harness lossCalculating a wire harness loss between an antenna feed point and a corresponding receiver feed point for each antenna, wherein ΔG _i Represents the wire harness loss between the antenna feed point of the ith antenna and the corresponding receiver feed point,/>Indicating the antenna gain reported by the i-th receiver's corresponding antenna at an angle q, polarization x based on the strength indication of the received signal,/>the gain of the first antenna radiation pattern at angle q, polarization x, for the antenna corresponding to the ith receiver is shown.

Specifically, since the RSSI is an estimate of the power of the receiver at the feed point thereof, the difference Δg between the gain of the antenna reported back based on the strength indication of the received signal and the gain of the first antenna radiation pattern is the wire harness loss between the antenna feed point and the corresponding receiver feed point, and it should be noted that this calculated value further includes the error of the RSSI measurement, that is:

wherein ΔG _i Representing the wire harness loss between the antenna feed point of the i-th antenna and the corresponding receiver feed point,indicating the antenna gain reported by the i-th receiver corresponding antenna at an angle Ω, polarization x, based on the strength indication of the received signal,/v>The gain of the first antenna radiation pattern at angle q, polarization x, for the antenna corresponding to the ith receiver is shown.

In an alternative embodiment of the present invention, the method for generating a plurality of transmission signals for measurement based on a plurality of second antenna radiation patterns specifically includes the steps of:

(1) Loading a plurality of second antenna radiation patterns into a channel simulator to simulate a wireless channel containing antenna characteristics of MIMO equipment to be tested;

specifically, it willThe information is loaded into a channel simulator to simulate a wireless channel containing antenna characteristics of the MIMO device to be tested.

(2) Each path of downlink signal output by the measuring instrument is input to a channel simulator to be convolved with a wireless channel

(3) And performing error elimination on the signals obtained by convolution to obtain a plurality of transmission signals for measurement.

Specifically, referring to fig. 6, the channel simulator convolves each downlink signal output from the measuring instrument with the wireless channel to obtain a convolved signal, as before,the error introduced by the RSSI measurement is included, and therefore, the convolved signal (i.e., the initial MIMO measurement transmitted signal) can be expressed as:

wherein,,representing the convolved signal (i.e., the initial MIMO measurement transmit signal), a>Representing the downlink signal output by the measuring instrument, H (t) representing the channel correlation matrix, E _i Indicating the error introduced by the RSSI measurement of the ith receiver, it can be seen that the calculated transmit signal for initial MIMO measurement +.>And an accurate measurement-use transmit signal +.>The difference between (see formulas in the background section) is the error introduced by the RSSI measurement of the receiver of the MIMO device under test.

The error can be eliminated and does not affect the accuracy of the wireless performance measurement of the MIMO device. In particular, the method comprises the steps of,error matrix is carried->Whereas acquisition of the propagation matrix P may be achieved by RSSI reporting, so that the measured value P of the propagation matrix is obtained by RSSI reporting _mea An error matrix E is also included.

P _mea ＝E·P

Therefore, the error elimination is carried out on the signals obtained by convolution, and the method specifically comprises the following steps:

inputting the signals obtained by convolution into an RF module for error elimination, wherein an error elimination matrix of the RF module is P _mea ^-1 ＝P ^-1 .E ^-1 ，P _mea ^-1 Representing an error cancellation matrix, P ^-1 An inverse matrix, E, representing the propagation matrix, P, (available) ^-1 Representing the inverse of the error matrix E.

Transmitted signal for initial measurementWhen passing through the RF module, at->Error matrix E in RF module and E in RF module ^-1 Cancellation is achieved so that the signal coming into the receiver is exactly equal to + ->Error cancellation is achieved and it can be seen that this way of error cancellation does not require the acquisition of the error matrix E.

The inventors consider that when the first antenna radiation pattern is measured, the gain of the first antenna radiation pattern is uncorrelated with the wire harness, and the measured first antenna radiation pattern is the same regardless of whether the cable length is 3m or 30 m. For MIMO devices with different wire harness losses (e.g. different cable lengths, or whether an amplifier is provided in the link), if their antenna radiation capacities are the same, the measured first antenna radiation patterns may be the same, and MIMO measurements with the first antenna radiation patterns will obtain the same wireless performance measurement results, which obviously violates the common sense in the art, i.e. the shorter the wire harness, the lower the loss, and the better the wireless performance. In the method for measuring the wireless performance of the MIMO equipment provided by the invention, the second antenna radiation pattern is used, namely, the antenna radiation pattern taking each receiver feed point of the MIMO equipment to be measured as a reference contains the influence of the wire harness part on the wireless performance measurement, so that the multi-channel measurement emission signal generated by the second antenna radiation pattern is more accurate, and the wireless performance measurement result of the MIMO equipment to be measured, which is obtained based on the accurate multi-channel measurement emission signal measurement, is also more accurate.

Embodiment two:

the embodiment of the invention also provides a wireless performance measurement system of the MIMO device, which adopts the wireless performance measurement method of the MIMO device in any one of the above embodiments to measure the wireless performance of the MIMO device to be measured, and comprises the following steps: the system comprises a measuring instrument, a channel simulator, an RF module, a measuring antenna and a communication antenna;

the measuring instrument is used for outputting a plurality of paths of downlink signals;

the channel simulator is used for simulating a wireless channel containing the antenna characteristics of the MIMO equipment to be tested and convolving a downlink signal with the wireless channel;

the RF module is used for carrying out error elimination on the signals obtained by convolution to obtain a plurality of transmission signals for measurement, and feeding the transmission signals for measurement into a plurality of measurement antennas;

the measuring antenna is used for transmitting the multi-channel measuring transmitting signals to the MIMO equipment to be measured, so that the MIMO equipment to be measured transmits uplink signals to the communication antenna after receiving the multi-channel measuring transmitting signals;

and the communication antenna is used for receiving the uplink signal and transmitting the uplink signal to the measuring instrument so that the measuring instrument can measure the wireless performance of the MIMO equipment to be measured.

The measuring instrument may be a base station or a base station simulator, or may be a comprehensive tester (comprehensive tester). The channel simulator and the RF module may be separate meters, or may be integrated into a comprehensive meter, and the measuring meter is not particularly limited herein.

Optionally, the channel simulator and the RF module are integrated in the measuring instrument.

Optionally, the method further comprises: an upper computer;

the upper computer is connected with the measuring instrument and used for controlling the measuring instrument to work.

Optionally, the method further comprises: the anechoic chamber is used for providing a measuring environment;

at least the measuring antenna and the communication antenna are arranged in the anechoic chamber.

The MIMO device under test includes a vehicle having a MIMO communication system.

In addition, in the description of embodiments of the present invention, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (11)

1. A wireless performance measurement method of a MIMO device, comprising:

acquiring a plurality of first antenna radiation patterns of the MIMO equipment to be tested, wherein the first antenna radiation patterns are antenna radiation patterns taking each antenna feed point of the MIMO equipment to be tested as a reference;

acquiring the strength indication returns of the received signals of a plurality of receivers of the MIMO equipment to be tested, and calculating the wire harness loss between the antenna feed point of each antenna and the corresponding receiver feed point based on the strength indication returns of the received signals of each receiver and the gain of the corresponding first antenna radiation pattern;

correcting the corresponding first antenna radiation patterns by adopting the harness loss to obtain a plurality of second antenna radiation patterns, wherein the second antenna radiation patterns are antenna radiation patterns taking each receiver feed point of the MIMO equipment to be tested as a reference;

and generating a plurality of transmission signals for measurement based on the radiation patterns of the second antennas, and feeding the plurality of transmission signals for measurement to the plurality of measurement antennas so as to measure the wireless performance of the MIMO device to be measured through the plurality of measurement antennas.

2. The method of claim 1, wherein calculating the beam loss between the antenna feed point and the corresponding receiver feed point for each antenna based on the strength indication return of the received signal for each receiver and the gain of the corresponding first antenna radiation pattern comprises:

calculating antenna gains of the antennas based on the strength indication payback of the received signals of each receiver;

and calculating the wire harness loss between the antenna feed point and the corresponding receiver feed point of each antenna according to the antenna gain reported by the intensity indication of the received signal of each antenna and the gain of the corresponding first antenna radiation pattern.

3. The method of claim 2, wherein calculating the antenna gain for each antenna based on the strength indication return for the received signal for each receiver comprises:

antenna gain calculation formula according to strength indication return based on received signalCalculating an antenna gain for each of the antennas based on a return of the strength indication of the received signal, wherein +_>Indicating the antenna gain reported based on the strength indication of the received signal at angle Ω, polarization x, RSSI for the antenna corresponding to the ith receiver _i Indicating return of strength indication of received signal of ith receiver, P _BSE Indicating the power of the signal output by the meter during active measurement, PL indicates the path loss in the measurement environment.

4. The method of claim 2, wherein calculating a beam loss between an antenna feed point and a corresponding receiver feed point for each of the antennas based on an antenna gain reported based on an indication of a strength of a received signal for each of the antennas and a gain of a corresponding first antenna radiation pattern, comprises:

calculating according to the wire harness lossCalculating a wire harness loss between an antenna feed point and a corresponding receiver feed point of each antenna, wherein delta G _i Represents the wire harness loss between the antenna feed point of the ith antenna and the corresponding receiver feed point,/>Indicating the antenna gain reported by the i-th receiver corresponding antenna at an angle Ω, polarization x, based on the strength indication of the received signal,/v>The gain of the first antenna radiation pattern at angle q, polarization x, for the antenna corresponding to the ith receiver is shown.

5. The method of claim 1, wherein generating a plurality of measurement transmit signals based on a plurality of the second antenna radiation patterns comprises:

loading a plurality of second antenna radiation patterns into a channel simulator to simulate a wireless channel containing the antenna characteristics of the MIMO equipment to be tested;

inputting each path of downlink signals output by the measuring instrument to the channel simulator, and convolving with the wireless channel;

and performing error elimination on the signals obtained by convolution to obtain a plurality of paths of transmitting signals for measurement.

6. The method of claim 5, wherein error cancellation is performed on the convolved signal, comprising:

inputting the convolved signal to an RF module, wherein the RF module calculates the convolved signal according to an error elimination matrix to eliminate errors, and the error elimination matrix is P _mea ^-1 ＝P ^-1 ·E ^-1 ，P _mea ^-1 Representing the error cancellation matrix, P ^-1 Representing a propagation matrixInverse matrix of P, E ^-1 Representing the inverse of the error matrix E.

7. A system for measuring wireless performance of a MIMO device, wherein the system for measuring wireless performance of a MIMO device measures wireless performance of a MIMO device to be measured by using the method for measuring wireless performance of a MIMO device according to any one of claims 1 to 6, the system for measuring wireless performance of a MIMO device comprising: the system comprises a measuring instrument, a channel simulator, an RF module, a measuring antenna and a communication antenna;

the measuring instrument is used for outputting a plurality of paths of downlink signals;

the channel simulator is used for simulating a wireless channel comprising the antenna characteristics of the MIMO equipment to be tested and convolving the downlink signal with the wireless channel;

the RF module is used for carrying out error elimination on the signals obtained by convolution to obtain a plurality of transmission signals for measurement, and feeding the plurality of transmission signals for measurement into a plurality of measurement antennas;

the measuring antenna is used for transmitting multiple paths of transmitting signals for measurement to the MIMO equipment to be measured, so that the MIMO equipment to be measured transmits uplink signals to the communication antenna after receiving multiple paths of transmitting signals for measurement;

and the communication antenna is used for receiving the uplink signal and sending the uplink signal to the measuring instrument so that the measuring instrument can measure the wireless performance of the MIMO equipment to be measured.

8. The system of claim 7, wherein the channel simulator and the RF module are integrated into the meter.

9. The system according to claim 7 or 8, further comprising: an upper computer;

the upper computer is connected with the measuring instrument and used for controlling the measuring instrument to work.

10. The system of claim 7, further comprising: the anechoic chamber is used for providing a measuring environment;

at least the measuring antenna and the communication antenna are arranged in the anechoic chamber.

11. The system of claim 7, wherein the MIMO device under test comprises a vehicle having a MIMO communication system.