Over-the-air radiation test system, method, and tester for wireless devices

Abstract

An over-the-air radiation test system, method and tester of a wireless device, first acquires the inverse matrix of the spatial transmission matrix corresponding to multiple sub-frequency bands between the tester and the wireless device, then divides the expected test signal with a preset frequency band into expected test signals corresponding to multiple sub-frequency bands according to the frequency band, and finally loads the inverse matrix of the spatial transmission matrix corresponding to each sub-frequency band into the expected test signal corresponding to the sub-frequency band to establish a virtual cable connection between the tester and the wireless device, and to implement over-the-air radiation testing of the wireless device, solving the problem of low isolation and low testing accuracy when using the radiation two-stage (RTS) method to perform testing due to the high unevenness of the amplitude and phase in the expected test signal with a preset frequency band having a wide bandwidth.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of communication testing, in particular to a wireless device over-the-air radiation test system, method and tester. BACKGROUND

[0002] Modern wireless technology uses a large number of MIMO (multi-input multi-output) technologies to improve data transmission speed. MIMO wireless devices have at least two receiver ports (connected to receiving antennas) or / and transmitter ports (connected to transmitting antennas). Among them, MIMO OTA testing is a multi-antenna whole machine performance testing method, which measures the receiving performance of wireless devices by simulating a channel model and realizing a complex electromagnetic environment in an anechoic chamber.

[0003] As shown in Figure 1 , there are M transmitting antennas in the base station, and the wireless device as the terminal has N receiving antennas. The signal is transmitted from the transmitting port of the base station to the receiver port of the wireless device, and passes through multiple paths, including direct paths and reflected paths. The basic parameters of the MIMO channel model include power distribution, angle of arrival (AoA), angle of departure (AoD), time delay, and Doppler effect, etc. These basic parameters are defined in detail in 3GPP. The channel model h n,m (t) between the mth transmitting port in the base station and the nth receiver port in the terminal can be described as follows:

[0004]

[0005] Wherein, l is one of L sub-paths, t is time, f is the center frequency of the test; ψl, Φ l and τ l are the main phase, Doppler effect and time delay of the lth sub-path, respectively; and (x represents antenna polarization) are the antenna gains of the nth receiving antenna of the terminal and the mth transmitting antenna of the base station, respectively, α l,AoA , β l,AoD and are the AoA, AoD and path loss from antenna polarization y to x in the lth sub-path.

[0006] In the traditional MIMO test, taking a 2x2 MIMO test as an example, as shown in Figure 2 , the output port of the channel simulator is usually directly connected to the antenna port of the wireless terminal by a cable, the antenna pattern set of the wireless terminal is integrated into the channel simulator for calculation, and finally the test signal is fed into the antenna port of the wireless terminal through the cable to realize the MIMO performance measurement of the wireless terminal. However, this test method will produce the following two problems:

[0007] (1) The conduction method makes the isolation between the two antenna links of the wireless terminal very high, while the isolation between the two antennas is limited when the wireless terminal is actually working.

[0008] (2) The impact of the noise of the wireless terminal itself on MIMO performance (i.e., Desense in related technologies) cannot be reflected in the test results.

[0009] In summary, the state of the wireless terminal is different from that of the whole device OTA measurement, so the conductive method cannot replace OTA measurement. In addition, with the widespread application of millimeter waves, many millimeter wave antennas are directly set on the millimeter wave module (AiP), and the entire module has no conductive interface, which also makes it impossible to realize millimeter wave MIMO measurement through conductive means.

[0010] The MIMO OTA testing methods in 3GPP and CTIA standards include the Radiation Two-Stage (RTS) method and the Multi-Probe Anechoic Chamber (MPAC) method. The MPAC method directly simulates the channel model by testing the spatial distribution of the probes. The RTS method establishes a one-to-one link between the transmitter and receiver through a "direct air interface" connection, similar to a cable connection (also known as a "virtual cable"). This method meets the requirements of whole-device testing, preserves the coupling between antennas and the noise interference between hardware and antennas, and more realistically reflects the MIMO performance of the wireless terminal. Summary of the Invention

[0011] The main technical problem this invention addresses is how to perform airborne radiation testing on wireless devices.

[0012] According to a first aspect, one embodiment provides an airborne radiation testing system for a wireless device, wherein the airborne radiation testing system includes a tester and at least two test antennas, wherein:

[0013] The test antenna is used to establish a wireless communication link between the tester and the wireless device, so that the tester and the wireless device can communicate wirelessly.

[0014] The testing instrument is configured to:

[0015] Obtain the inverse matrix of the spatial transmission matrix between the tester and the wireless device in multiple sub-frequency bands;

[0016] Obtain a desired test signal with a preset frequency band, and divide the desired test signal with the preset frequency band into multiple sub-frequency bands according to the frequency band; wherein, the frequency range composed of the multiple sub-frequency bands is the frequency range corresponding to the preset frequency band;

[0017] loading the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the respective sub-band to obtain a transmission test signal corresponding to each sub-band, so as to establish a virtual cable connection between the test instrument and the wireless device and perform over-the-air radiation testing on the wireless device.

[0018] According to a second aspect, an embodiment provides an over-the-air radiation testing method of a wireless device, wherein the over-the-air radiation testing method comprises:

[0019] obtaining an inverse matrix of a spatial transmission matrix corresponding to a plurality of sub-bands between the test instrument and the wireless device;

[0020] obtaining an expected test signal having a preset frequency band, and dividing the expected test signal having the preset frequency band into expected test signals corresponding to a plurality of sub-bands according to frequency bands; wherein a frequency range composed of the plurality of sub-bands is a frequency range corresponding to the preset frequency band;

[0021] loading the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the respective sub-band to obtain a transmission test signal corresponding to each sub-band, so as to establish a virtual cable connection between the test instrument and the wireless device and perform over-the-air radiation testing on the wireless device.

[0022] According to a third aspect, an embodiment provides a test instrument, comprising:

[0023] an inverse matrix obtaining module configured to obtain an inverse matrix of a spatial transmission matrix corresponding to a plurality of sub-bands between the test instrument and the wireless device;

[0024] a sub-band obtaining module configured to obtain an expected test signal having a preset frequency band, and divide the expected test signal having the preset frequency band into expected test signals corresponding to a plurality of sub-bands according to frequency bands; wherein a frequency range composed of the plurality of sub-bands is a frequency range corresponding to the preset frequency band;

[0025] an inverse matrix loading module configured to load the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the respective sub-band to obtain a transmission test signal corresponding to each sub-band, so as to establish a virtual cable connection between the test instrument and the wireless device and perform over-the-air radiation testing on the wireless device.

[0026] According to a fourth aspect, an embodiment provides a computer readable storage medium, wherein a program is stored on the medium, and the program can be executed by a processor to implement the over-the-air radiation testing method according to any one of the above embodiments.

[0027] The over-the-air radiation test system, method and tester of the wireless device according to the above embodiment obtain the inverse matrix of the spatial transmission matrix corresponding to the plurality of sub-frequency bands between the tester and the wireless device, divide the expected test signal with the preset frequency band into the expected test signal corresponding to the plurality of sub-frequency bands according to the frequency band, and finally load the inverse matrix of the spatial transmission matrix corresponding to each sub-frequency band into the expected test signal corresponding to the sub-frequency band to establish a virtual cable connection between the tester and the wireless device, thereby realizing the over-the-air radiation test on the wireless device. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A schematic diagram of a MIMO channel model in the prior art;

[0029] Figure 2 A structural schematic diagram of an existing 2x2 multiple-input multiple-output (MIMO) test system;

[0030] Figure 3 A schematic diagram of a cross signal in a 2x2 multiple-input multiple-output (MIMO) test system;

[0031] Figure 4 A schematic diagram of a total transmission matrix in a 2x2 multiple-input multiple-output (MIMO) test system;

[0032] Figure 5 A structural schematic diagram of an over-the-air radiation test system of a wireless device according to an embodiment;

[0033] Figure 6 A schematic diagram of dividing an expected test signal with a preset frequency band into a plurality of sub-frequency bands;

[0034] Figure 7 A flowchart of an over-the-air radiation test method of a wireless device according to an embodiment;

[0035] Figure 8 A structural schematic diagram of a tester according to an embodiment. DETAILED DESCRIPTION

[0036] The application will be described in further detail below with specific reference being made to the drawings. Like elements are referenced with like numerals throughout the specification and figures. Many of the details of the application are described in order to provide a thorough understanding thereof. One skilled in the art, however, will readily recognize that the application can be practiced without many of the details given, that the application is not limited to the described embodiments, and that work incorporating modifications will fall within the scope of the application. In the following description, numerous specific details are discussed to provide a thorough understanding of the application. However, one will recognize that the application can be practiced without one or more of the specific details. In other instances, well-known structures have not been described in order to avoid obscuring the application. The various concepts can be implemented in different ways and should not be construed to be limited to the examples described or shown in the figures.

[0037] In addition, features, operations, or steps described in the specification can be combined in any suitable manner without departing from the scope of the application. Similarly, the various steps or actions in a method can be combined, reordered, or split into further steps or actions without departing from the scope of the application. Accordingly, the description and drawings are to be regarded as illustrative in nature and not as restrictive.

[0038] The serial numbers of components in the specification, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any sequential or technical meaning. Unless otherwise specified, the terms "connected" and "coupled" in the application include direct and indirect connections (couplings).

[0039] The radiation two-stage (RTS) method in the MIMO OTA test method is introduced below.

[0040] In the MIMO OTA test, the expressions of the transmitted test signal and the received test signal are as follows:

[0041] y(t) = H(t) * x(t)

[0042] where y(t) is the received test signal, x(t) is the transmitted test signal, and H(t) is a spatial transmission matrix. Taking an N×N test system composed of N test antennas and N receiver ports of a wireless device as an example, the expression of the spatial transmission matrix H(t) is as follows:

[0043]

[0044] where h 1,1 (t) represents the transmission parameter corresponding to the communication link between the first transmitting port (connected to the first test antenna, the same below) of the test instrument and the first receiver port of the wireless device, h1,N (t) represents the transmission parameter corresponding to the communication link between the Nth transmit port of the tester (connected with the Nth test antenna, same below) and the 1st receiver port of the wireless device, h N,1 (t) represents the transmission parameter corresponding to the communication link between the 1st transmit port of the tester and the Nth receiver port of the wireless device, h N,N (t) represents the transmission parameter corresponding to the communication link between the Nth transmit port of the tester and the Nth receiver port of the wireless device.

[0045] Due to the cross-transmission between the test antenna and the receiver port of the wireless device, the elimination of the cross signal caused by the cross-transmission is realized by loading the inverse matrix M(t) of the space transmission matrix in front of the transmit port of the tester. The expression of the inverse matrix M(t) of the space transmission matrix in the N x N system is:

[0046]

[0047] wherein m 1,1 (t) represents the inverse transmission parameter corresponding to the communication link between the 1st transmit port of the tester and the 1st receiver port of the wireless device, m 1,N (t) represents the inverse transmission parameter corresponding to the communication link between the Nth transmit port of the tester and the 1st receiver port of the wireless device, m N,1 (t) represents the inverse transmission parameter corresponding to the communication link between the 1st transmit port of the tester and the Nth receiver port of the wireless device, m N,N (t) represents the inverse transmission parameter corresponding to the communication link between the Nth transmit port of the tester and the Nth receiver port of the wireless device.

[0048] Taking the 2 x 2 MIMO receiving performance test as an example, as shown in Figure 3 The base station simulator and the channel simulator in the tester combine the antenna directional pattern processing to obtain the transmit signal. During the test, the required transmit signal is the signal transmitted from the 1st transmit port of the tester to the 1st receiver port of the wireless device and the signal transmitted from the 2nd transmit port of the tester to the 2nd receiver port of the wireless device. Therefore, the cross signal transmitted from the 1st transmit port to the 2nd receiver port of the wireless device and the cross signal transmitted from the 2nd transmit port to the 1st receiver port of the wireless device is the interference signal in the MIMO test. The space transmission matrix H in the 2 x 2 test system can be written as:

[0049]

[0050] Due to the existence of cross-link, the test signal integrated with the channel model cannot be correctly transmitted to each receiver port of the wireless device. Therefore, the inverse matrix is used to eliminate the influence of cross-transmission, realizing the "air interface direct connection" between the tester and the wireless device, that is, the virtual cable connection. The inverse matrix can be realized by the amplifiers, attenuators and phase shifters (or digital signal processing) in the channel simulator.

[0051] After loading the inverse matrix of the spatial transmission matrix, the relationship between the transmitted signal and the received signal becomes:

[0052] y(t) = [H(t)M(t)] * x(t)

[0053] As shown in Figure 4 , the total transmission matrix T of the 2x2 MIMO system is defined as:

[0054]

[0055] wherein,

[0056]

[0057] In an ideal case, the T matrix is the unit matrix, that is, t 11 =t 22 =1, t 12 =t 21 =0, at this time, the test signal emitted from the transmitting port 1 of the tester is only transmitted to the receiver port 1 of the wireless device, the test signal emitted from the transmitting port 2 of the tester is only transmitted to the receiver port 2 of the wireless device, and the cross signal is eliminated due to the introduction of the inverse matrix. However, in the actual link, due to the limited signal reflection in the test system, the limited power and the limited accuracy of phase adjustment, the cross signal cannot be completely eliminated, therefore, in order to evaluate the influence of the cross channel on the test accuracy, the concept of isolation is introduced in the related art, the isolation describes the amplitude relationship between the cross signal and the expected signal, and the definition of the isolation is as follows:

[0058] Ios1 = |t 11 / t 12 |

[0059] Ios2 = |t 22 / t 21 |

[0060] Ios t = min(Ios1, Ios2)

[0061] wherein, Ios1 and Ios2 respectively represent the ratio of the expected signal to the cross signal of the receiver port 1 of the wireless device and the receiver port 2 of the wireless device, and Ios tis the system isolation of the 2x2 MIMO test system. When the isolation reaches a certain preset value, it is considered that good "air interface direct connection" can be achieved. In MIMO OTA testing, isolation is one of the important factors affecting test error, which is related to the relative position of the wireless device and the test antenna, and the antenna pattern of the wireless device and the test antenna.

[0062] Therefore, the RTS method first obtains the antenna radiation pattern and the spatial transmission matrix of the wireless device, then obtains the inverse matrix of the spatial transmission matrix, and introduces the calculation of the inverse matrix in the test signal to offset the spatial transmission matrix, to realize the "air interface direct connection" between the base station emulator (BSE) and the wireless device under test (DUT) for MIMO OTA testing.

[0063] With the increase of communication bandwidth and the gradual complexity of communication link design, the amplitude and phase flatness in the link causes the isolation of the receiver port of the wireless device to decrease within the bandwidth, thereby bringing serious challenges to MIMO measurement. Radio frequency components in the link, such as radio frequency cables, amplifiers, attenuators, filters, etc., will modulate the amplitude and phase in different ways within the bandwidth. When the test signal is a narrowband signal, the signal distortion caused by this modulation is not obvious, but with the increase of bandwidth, the amplitude and phase of different signals arriving at the test center have large changes at different frequencies within the bandwidth. This amplitude and phase flatness within the wideband will cause large test errors when performing MIMO testing, whether using the existing radiation two-stage (RTS) method or the multi-probe anechoic chamber (MPAC) method.

[0064] In 4G MIMO testing, the test signal is a narrowband signal (frequency less than or equal to 20MHz), and since the amplitude and phase within the frequency band of the narrowband signal change less, it has good consistency with the center frequency. The inverse matrix of the spatial transmission matrix obtained according to the center frequency of the frequency band in the above RTS method can achieve good isolation (e.g. more than 20dB) in the entire frequency band, so the amplitude and phase flatness problem can be ignored. In 5G wideband MIMO testing, with the increase of system bandwidth, the amplitude and phase change dramatically within the wide frequency band. If the inverse matrix of the spatial transmission matrix calculated according to the center frequency of the frequency band in the above RTS method is applied within the entire wide frequency band, it will result in poor isolation of the antenna, making it difficult to achieve "air interface direct connection", leading to high uncertainty of MIMO testing, and even unable to evaluate the real performance of the wireless device under test.

[0065] In the embodiment of the present application, the wide-band test signal is divided into multiple narrow-band test signals, the inverse matrix of the spatial transfer matrix is calculated in each narrow-band, and the inverse matrix of the spatial transfer matrix is loaded into the narrow-band test signal to realize the over-the-air radiation test of the wireless device.

[0066] Please refer to Figure 5 The embodiment of the present application provides an over-the-air radiation test system of a wireless device, wherein the wireless device 200 is the wireless device to be tested, and the wireless device 200 has at least two receiver ports 202 (transmitter ports 203), and each receiver port 202 (transmitter port 203) is connected to a receiving / transmitting antenna 201. The over-the-air radiation test system provided by the embodiment comprises a test antenna 101 and a test instrument 102, the test instrument 101 has at least two transmitting ports 103 (receiving ports 104), each transmitting port 103 (receiving port 104) is connected to a test antenna 101, and the test antenna 101 establishes a wireless communication link between the test instrument 102 and the wireless device 200 to realize the wireless communication between the test instrument 102 and the wireless device 200. The test instrument 102 is connected to the test antenna 101 and the wireless device 200 through a cable or wireless connection. An anechoic chamber 300 is used to provide an electromagnetic environment for testing. It should be noted that Figure 5 In the embodiment, the test instrument 102 is placed inside the anechoic chamber 300, and in other embodiments, the test instrument 102 can also be placed outside the anechoic chamber 300.

[0067] The test instrument 102 is configured to perform the following operations to realize the over-the-air radiation test of the wireless device 200:

[0068] (1) Obtain the inverse matrix of the spatial transfer matrix corresponding to multiple sub-bands between the test instrument 102 and the wireless device 200.

[0069] In an embodiment, obtaining the inverse matrix of the spatial transfer matrix corresponding to multiple sub-bands between the test instrument 102 and the wireless device 200 comprises: obtaining a downlink inverse matrix, and / or obtaining an uplink inverse matrix. The downlink inverse matrix is the inverse matrix of the spatial transfer matrix corresponding to multiple sub-bands between the test instrument 102 and the receivers of the wireless device 200, and the uplink inverse matrix is the inverse matrix of the spatial transfer matrix corresponding to multiple sub-bands between the transmitters of the wireless device 200 and the test instrument. Details are as follows.

[0070] (1) When the wireless device 200 performs a receiving performance test, the downlink inverse matrix is obtained by the following method.

[0071] Each of the transmitting ports 103 of the tester 102 transmits a respective sub-band signal, and the magnitude variation of each of the sub-band signals transmitted by each of the transmitting ports 103 of the tester 102 and received by each of the receiver ports 201 of the wireless device 200 is obtained. In this embodiment, the transmitting port 103 that transmits the current signal is referred to as the current transmitting port 103, and the other transmitting ports 103 are in a closed state. When the current transmitting port 103 transmits a signal, the current transmitting port 103 can be controlled to transmit each of the sub-band signals one by one. When the current transmitting port 103 transmits a current sub-band signal, one or more receiver ports 201 of the wireless device 200 can be controlled to receive the current sub-band signal, or all of the receiver ports 201 of the wireless device 200 can be controlled to receive the current sub-band signal simultaneously. After the magnitude variation of the current sub-band signal received by all of the receiver ports 201 of the wireless device 200 is obtained, the current transmitting port 103 can be controlled to transmit a next sub-band signal, and the magnitude variation of each of the sub-band signals transmitted by the current transmitting port 103 and received by all of the receiver ports 201 of the wireless device 200 is obtained. In this way, each of the transmitting ports 103 of the tester 102 can be taken as the current transmitting port 103 one by one, and the magnitude variation of each of the sub-band signals transmitted by each of the transmitting ports 103 and received by each of the receiver ports 201 of the wireless device 200 can be obtained.

[0072] The test instrument 102 transmits each sub-band signal multiple times by any two of the transmitting ports 103 with different phase differences, and obtains the phase difference of each sub-band signal transmitted by any two of the transmitting ports 103 received by each receiver port 201 of the wireless device 200. In the embodiment, the transmitting ports 103 currently transmitting signals are taken as the first current transmitting port 103 and the second current transmitting port 103, and the other transmitting ports 103 are in the closed state. When the first current transmitting port 103 and the second current transmitting port 103 transmit the current sub-band signal with different phase differences, one or more receiver ports 201 of the wireless device 200 can be controlled to receive the current sub-band signal, or all receiver ports 201 of the wireless device 200 can be controlled to receive the current sub-band signal simultaneously. After the phase difference of the current sub-band signal received by the receiver port 201 of the wireless device 200 is obtained, the first current transmitting port 103 and the second current transmitting port 103 are controlled to transmit the next sub-band signal multiple times with different phase differences, and finally the phase difference of each sub-band signal transmitted by the first current transmitting port 103 and the second current transmitting port 103 received by all receiver ports 201 of the wireless device 200 is obtained. By analogy, any two of the transmitting ports 103 are taken as the first current transmitting port 103 and the second current transmitting port 103 one by one, and the phase difference of each sub-band signal transmitted by any two of the transmitting ports 103 received by each receiver port 201 of the wireless device 200 is obtained.

[0073] In an embodiment, the calculation of the phase difference of the current sub-band signal received by the receiver port 201 of the wireless device 200 is as follows: according to the amplitudes of the current sub-band signal transmitted by the first current transmitting port 103 and the second current transmitting port 103 respectively and the amplitude of the resultant signal (i.e. the signal transmitted by the first current transmitting port 103 and the second current transmitting port 103 together), the phase difference is calculated by Fourier series fitting or Fourier transform. In another embodiment, the calculation of the phase difference can also be as follows: first, according to the amplitudes of the current sub-band signal transmitted by the first current transmitting port 103 and the second current transmitting port 103 respectively, a resultant amplitude reference value is calculated, wherein the resultant amplitude reference value is the calculated amplitude of the resultant signal obtained when the aforesaid respectively transmitted current sub-band signals are combined with different phase differences at each receiver port 201 of the wireless device 200; then, according to the calculated resultant amplitude reference value and the amplitude of the resultant signal obtained by the test, the phase difference is calculated.

[0074] The amplitude variation and phase difference of each sub-band signal transmitted by the tester 102 and received by the wireless device 200 are used to determine the spatial transmission matrix corresponding to each sub-band between the transmission port 103 of the tester 102 and the receiver port 202 of the wireless device 200, and then the inverse matrix of the spatial transmission matrix is obtained.

[0075] In an embodiment, the spatial transmission matrix corresponding to the i-th sub-band is obtained according to the following expression, taking the n transmission ports 103 and n receiver ports 202 as an example:

[0076]

[0077] where f i represents the center frequency of the i-th sub-band, i is the index number of the sub-band, i = 1, 2, …, I, and I is the number of sub-bands; p vk represents the amplitude variation of the signal transmitted by the k-th transmission port 103 and received by the v-th receiver port 202, represents the phase difference of the signal transmitted by the k-th transmission port 103 and received by the v-th receiver port 202, v = 1, 2, …, n, and k = 1, 2, …, n.

[0078] The inverse matrix M i (f i ) of the spatial transmission matrix corresponding to the i-th sub-band is obtained according to the following expression:

[0079]

[0080] where f i represents the center frequency of the i-th sub-band, i is the index number of the sub-band, i = 1, 2, …, I, and I is the number of sub-bands; m i,vk (f i ) represents the inverse transmission parameter of the signal transmitted by the k-th transmission port 103 and received by the v-th receiver port 202.

[0081] In this embodiment, the inverse matrix M W of the wideband spatial transmission matrix corresponding to the preset frequency band is obtained according to the following expression:

[0082]

[0083] where m′ v,k = [m 1,vk (f1) … m i,vk (f i ) … m I,vk (f I )]; m′ v,krepresents the inverse matrix of the transmission matrix of the wireless communication link between the kth transmitter port 103 and the vth receiver port 202 at frequencies f1,...,f i ,...f I Actually, it is a vector, and each value in the vector is the inverse transmission parameter corresponding to each sub-band. v,k Actually, it is a vector, and each value in the vector is the inverse transmission parameter corresponding to each sub-band.

[0084] (2) The wireless device 200 obtains the uplink inverse matrix when performing the transmission performance test in the following manner.

[0085] Each transmitter port 204 of the wireless device 200 respectively transmits each sub-band signal, and obtains the amplitude variation of each sub-band signal respectively transmitted by each transmitter port 204 of the wireless device 200 and received by each receiver port 104 of the tester 102. In this embodiment, the transmitter port 204 of the current transmission signal is taken as the current transmitter port 204, and at this time, other transmitter ports 204 are in the closed state. When the current transmitter port 204 transmits a signal, the current transmitter port 204 can be controlled to transmit each sub-band signal one by one. When the current transmitter port 204 transmits a current sub-band signal, one or more receiver ports 104 of the tester 102 can be controlled to receive the current sub-band signal, or all receiver ports 104 of the tester 102 can be controlled to simultaneously receive the current sub-band signal. After the amplitude variation of the current sub-band signal received by all receiver ports 104 of the tester 102 is obtained, the next sub-band signal is transmitted by the current transmitter port 204. Finally, the amplitude variation of each sub-band signal respectively transmitted by the current transmitter port 204 and received by all receiver ports 104 of the tester 102 is obtained. In this way, each transmitter port 204 is taken as the current transmitter port 204 one by one, and the amplitude variation of each sub-band signal respectively transmitted by each transmitter port 204 and received by each receiver port 104 of the tester 102 is obtained.

[0086] The wireless device 200 transmits each sub-band signal multiple times with different phase differences between any two transmitter ports 204, and obtains the phase difference of each sub-band signal transmitted by any two transmitter ports 204 received by each receiving port 104 of the tester 102. In the embodiment, the transmitter ports 204 currently transmitting signals are taken as the first current transmitter port 204 and the second current transmitter port 204, and the other transmitter ports 204 are in the off state. When the first current transmitter port 204 and the second current transmitter port 204 transmit the current sub-band signal with different phase differences, one or more receiving ports 104 of the tester 102 can be controlled to receive the current sub-band signal, or all receiving ports 104 of the tester 102 can be controlled to receive the current sub-band signal at the same time. After the phase difference of the current sub-band signal received by the receiving port 104 of the tester 102 is obtained, the first current transmitter port 204 and the second current transmitter port 204 are controlled to transmit the next sub-band signal multiple times with different phase differences, and finally the phase differences of each sub-band signal transmitted by the first current transmitter port 204 and the second current transmitter port 204 and received by all receiving ports 104 of the tester 102 are obtained. By analogy, any two transmitter ports 204 are taken as the first current transmitter port 204 and the second current transmitter port 204 one by one, and the phase differences of each sub-band signal transmitted by any two transmitter ports 204 and received by each receiving port 104 of the tester 102 are obtained.

[0087] The amplitude variation and the phase difference of each sub-band signal transmitted by the wireless device 200 and received by the tester 102 are used to determine the spatial transmission matrix between the transmitter ports 204 of the wireless device and the tester in multiple sub-bands, and thus the inverse matrix of the spatial transmission matrix is obtained.

[0088] It should be noted that the working state of the tester and the wireless device can be a transmitting state or a receiving state. The specific way of obtaining the downlink inverse matrix through the receiving performance test has been described in detail in the above embodiment. According to the reciprocity principle, the test results obtained through the transmitting performance test and the receiving performance test should be consistent. Therefore, the specific way of obtaining the uplink inverse matrix through the transmitting performance test is not described herein.

[0089] (II) The tester 102 acquires the expected test signal with the preset frequency band, and divides the expected test signal with the preset frequency band into a plurality of expected test signals corresponding to a plurality of sub-frequency bands according to the frequency band; wherein the frequency range composed of the plurality of sub-frequency bands is the frequency range corresponding to the preset frequency band. In the embodiment, the preset frequency band is a frequency band with a relatively wide frequency range, for example, the frequency band commonly used in 5G communication is 100MHz or 400MHz. It should be noted that when the preset frequency band is divided into a plurality of sub-frequency bands, in general, the more the sub-frequency bands are divided, the smaller the amplitude difference of the signals in each sub-frequency band, and the higher the final test accuracy. However, too many frequency bands will cause excessive occupation of the control processor (FPGA or DSP) resources in the tester 102, therefore, in the embodiment, the phase difference of the expected test signals in any two sub-frequency bands is less than a preset phase value, in an embodiment, the preset phase value can be 10°, as shown in Figure 6 For a preset frequency band of 100MHz, the number of divided sub-frequency bands is 10 (B1, B2, …, B10), and those skilled in the art can understand that the preset phase value can be adjusted according to actual application requirements, which is not limited in the embodiment.

[0090] In addition, the expected test signal with the preset frequency band acquired by the tester 102 is a time domain signal, and the embodiment needs to convert the expected test signal with the preset frequency band from the time domain to the frequency domain, and in the frequency domain, the expected test signal with the preset frequency band is divided into a plurality of expected test signals corresponding to a plurality of sub-frequency bands according to the frequency band. As an example, the discrete Fourier transform can be used to convert the expected test signal with the preset frequency band from the time domain to the frequency domain.

[0091] In an embodiment, taking the wireless communication link between the tester 102 and the receiver port of the wireless device 200 as an example, the specific operation is as follows:

[0092] (2-1) Acquire the expected test signal with the preset frequency band required for the wireless communication link between the kth transmitter port 103 of the tester 102 and the vth receiver port 202 of the wireless device 200 v,k (p); wherein k is the index number of the transmitter port 103 of the tester 102, and v is the index number of the receiver port 202 of the wireless device 200.

[0093] (2-2) Convert the expected test signal with the preset frequency band required for the wireless communication link between the kth transmitter port 103 of the tester 102 and the vth receiver port 202 of the wireless device 200 v,k (p) from the time domain to the frequency domain, to obtain the expected test signal with the preset frequency band in the frequency domain for the wireless communication link between the kth transmitter port 103 of the tester 102 and the vth receiver port 202 of the wireless device 200 v,k(w) As an example, the desired test signal x with the preset frequency band is obtained by the following expression v,k (p) converting from the time domain to the frequency domain:

[0094]

[0095] wherein P is the length of the discrete Fourier transform, and can be 128, 256, 512 or 1024.

[0096] (2-3) dividing the desired test signal X in the frequency domain into a plurality of sub-band corresponding desired test signals to obtain a plurality of sub-band corresponding desired test signals X v,k (w) in the frequency domain. i,vk

[0097] (Three) the tester 102 loads the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the corresponding sub-band corresponding desired test signal to obtain the transmission test signal corresponding to each sub-band, so as to establish a virtual cable connection between the wireless device 200 and the test antenna 101, and perform the over-the-air radiation test on the wireless device 200. The tester 102 performs the over-the-air radiation test on the wireless device 200 at least one of the following: control the test antenna 101 to transmit the transmission test signal of the preset frequency band to the wireless device 200 to obtain the wireless receiving performance of the wireless device 200; or, control the wireless device 200 to transmit the transmission test signal of the preset frequency band to the test antenna 101 to obtain the wireless transmitting performance of the wireless device 200.

[0098] In this embodiment, the tester 102 loads the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the corresponding sub-band corresponding desired test signal in the frequency domain, so it is also necessary to convert the transmission test signal corresponding to each sub-band in the frequency domain to the time domain. As an example, the inverse discrete Fourier transform can be used to convert the transmission test signal corresponding to each sub-band in the frequency domain to the time domain.

[0099] In an embodiment, taking the wireless communication link between the tester 102 and the receiver port of the wireless device 200 as an example, the specific operation is as follows:

[0100] (3-1) loading the inverse transmission parameter vector (m' v,k = [m 1,vk (f1)…m i,vk (f i )…m I,vk (f I )]) of the wireless communication link between the kth transmitter port 103 of the tester 102 and the vth receiver port 202 of the wireless device 200 in the inverse matrix of the spatial transmission matrix corresponding to each sub-band to the plurality of sub-band corresponding desired test signals X​i,vk (w) the transmit test signal X corresponding to each sub-frequency band in the frequency domain of the wireless communication link between the kth transmit port 103 of the tester 102 and the vth receiver port 202 of the wireless device 200 is obtained i ,vk (w).

[0101] The transmit test signal X corresponding to each sub-frequency band in the frequency domain of the wireless communication link between the kth transmit port 103 of the tester 102 and the vth receiver port 202 of the wireless device 200 is determined according to the following expression i ,vk (w):

[0102] X i ,vk (w) = X i,vk (w) m i,vk (f i ).

[0103] (3-2) The transmit test signal X corresponding to each sub-frequency band in the frequency domain is converted from the frequency domain to the time domain to obtain the transmit test signal x corresponding to each sub-frequency band of the wireless communication link between the kth transmit port 103 of the tester 102 and the vth receiver port 202 of the wireless device 200 i ,vk (w). i ,vk (p) As an example, the transmit test signal X corresponding to each sub-frequency band is converted from the frequency domain to the time domain according to the following expression i ,vk (w):

[0104]

[0105] (3-3) In an embodiment, the transmit test signal of the kth transmit port 103 of the tester 102 at each sub-frequency band is as follows:

[0106]

[0107] wherein Tx i,v represents the transmit test signal of the kth transmit port 103 of the tester 102 at the i-th sub-frequency band.

[0108] ​​​​​​The embodiment of the present application divides the expected test signal of the preset frequency band with wide bandwidth into a plurality of sub-band corresponding expected test signals, and then loads the inverse matrix of the obtained spatial transmission matrix corresponding to each sub-band into the corresponding expected test signal, so as to realize the over-the-air radiation test of the wireless device, and solve the problem of low isolation and low test accuracy when the RTS method is used to perform the test due to the high unevenness of the amplitude and phase of the expected test signal of the preset frequency band with wide bandwidth.

[0109] Please refer to Figure 7 , Figure 7 The over-the-air radiation method of the wireless device is shown in the flowchart of an embodiment, and the over-the-air radiation method provided by the embodiment is applied to a test instrument, and includes steps 10 to 30, which are described in detail below.

[0110] Step 10: Obtain the inverse matrix of the spatial transmission matrix corresponding to a plurality of sub-bands between the test instrument and the wireless device.

[0111] In an embodiment, in step 10, obtaining the inverse matrix of the spatial transmission matrix corresponding to a plurality of sub-bands between the test instrument and the wireless device includes: obtaining a downlink inverse matrix, and / or obtaining an uplink inverse matrix. The downlink inverse matrix is the inverse matrix of the spatial transmission matrix corresponding to a plurality of sub-bands between the test instrument and the receiver of the wireless device, and the uplink inverse matrix is the inverse matrix of the spatial transmission matrix corresponding to a plurality of sub-bands between the transmitter of the wireless device and the test instrument.

[0112] In an embodiment, obtaining the downlink inverse matrix includes:

[0113] Step 11-1: Obtain the amplitude variation of the sub-band signal received by each receiver port of the wireless device and respectively transmitted by each transmitting port of the test instrument. This step needs to perform signal transceiving multiple times. In each execution, only one transmitting port transmits a signal, and the other transmitting ports are closed. In a single execution, one or more receiver ports of the wireless device can be controlled to receive a signal, or all antennas of the wireless device can be controlled to receive simultaneously to improve efficiency. As an embodiment, the amplitude of the signal received by each receiver port of the wireless device can be obtained through the power report of each receiver port of the wireless device, such as RSSI (Reference Signal Strength Indicator, received signal strength indicator) or RSRP (Reference Signal Received Power, reference signal received power). In this embodiment, in each execution, the test antennas that transmit signals can be controlled to transmit signals of each sub-band one by one to obtain the amplitude variation of the sub-band signal received by each receiver port and respectively transmitted by the transmitting port.

[0114] Step 12-1: Obtain the phase difference of each sub-band signal received by each receiver port of the wireless device and transmitted by any two transmitting ports of the tester simultaneously. This step can be implemented by controlling any two transmitting ports to transmit the signals of each sub-band multiple times with different phase differences, obtaining the amplitude of the resultant signal received by each receiver port, and obtaining the phase difference of each sub-band signal received by each receiver port of the wireless device and transmitted by any two transmitting ports of the tester according to the amplitude of each sub-band signal transmitted by any two transmitting ports of the tester and the amplitude of the resultant signal received by each receiver port. This step needs to be implemented multiple times. Each time, two transmitting ports transmit signals, and other transmitting ports are closed. Optionally, in a single implementation, one or more receiver ports of the wireless device can be controlled to receive signals, or all receiver ports can be controlled to receive simultaneously to improve efficiency. As an embodiment, the phase difference is calculated according to the amplitude of the signals transmitted by any two transmitting ports and the amplitude of the resultant signal (i.e., the signals transmitted by the two transmitting ports simultaneously) received by each receiver port of the wireless device by Fourier series fitting or Fourier transform. As another embodiment, the phase difference is calculated as follows. First, a resultant amplitude reference value is calculated according to the amplitude of the signals transmitted by any two transmitting ports. The resultant amplitude reference value is the calculated amplitude of the resultant signal when the signals transmitted by any two transmitting ports are combined at each receiver port of the wireless device with different phase differences. Then, the phase difference is calculated according to the calculated resultant amplitude reference value and the amplitude of the resultant signal obtained by the test. In this embodiment, any two transmitting ports that transmit signals can be controlled to transmit the signals of each sub-band one by one to obtain the phase difference of each sub-band signal received by each receiver port of the wireless device and transmitted by any two transmitting ports of the tester.

[0115] Step 13-1: Obtain the inverse matrix of the spatial transmission matrix between the tester and the receivers of the wireless device corresponding to each sub-band according to the amplitude variation and the phase difference corresponding to each sub-band. That is, each sub-band corresponds to an inverse matrix of a spatial transmission matrix. It should be noted that the construction method of the inverse matrix of the spatial transmission matrix has been described in detail in the above embodiment, and will not be described here.

[0116] In an embodiment, obtaining the uplink inverse matrix comprises:

[0117] Step 11-2: Obtain the amplitude variation of each sub-band signal received by each receiving port of the tester and transmitted by each transmitter port 204 of the wireless device.

[0118] Step 12-2: Obtain the phase difference of each sub-band signal simultaneously transmitted by any two transmitter ports 204 of the wireless device received by each receiving port of the tester.

[0119] Step 12-3: Obtain the inverse matrix of the spatial transmission matrix corresponding to the plurality of sub-bands between the receiver of the wireless device and the tester according to the amplitude variation and the phase difference corresponding to each sub-band signal.

[0120] It should be noted that the working state of the tester and the wireless device can be a transmitting state or a receiving state. The specific manner of obtaining the downlink inverse matrix through the receiving performance test has been described in detail in the above embodiment. According to the reciprocity principle, the test results obtained by the transmitting performance test and the receiving performance test should be consistent. Therefore, the specific manner of obtaining the uplink inverse matrix through the transmitting performance test is not described again in this embodiment.

[0121] Step 20: Obtain the expected test signal with the preset frequency band, and divide the expected test signal with the preset frequency band into expected test signals corresponding to a plurality of sub-bands according to the frequency band; wherein the frequency range composed of the plurality of sub-bands is the frequency range corresponding to the preset frequency band. In this embodiment, the more the number of sub-bands divided by the preset frequency band, the better in theory. When the number of sub-bands is larger, the phase change of the signal in each sub-band will be very small. However, too many sub-bands will occupy more resources of the control processor in the tester. Therefore, a suitable sub-band data needs to be selected. In this embodiment, the expected test signals corresponding to the plurality of sub-bands need to satisfy that the phase difference of the expected test signals corresponding to any two sub-bands is less than a preset phase value. The preset phase value is 10° in this embodiment. It should be noted that this embodiment divides the expected test signal with the preset frequency band into expected test signals corresponding to a plurality of sub-bands according to the frequency band in the frequency domain. Therefore, the expected test signal with the preset frequency band needs to be converted from the time domain to the frequency domain first, and then divided into expected test signals corresponding to a plurality of sub-bands.

[0122] Step 30: load the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the respective sub-band to obtain the transmission test signal corresponding to each sub-band, so as to establish a virtual cable connection between the tester and the wireless device and perform the over-the-air radiation test on the wireless device. The tester performing the over-the-air radiation test on the wireless device at least includes one of the following: controlling the test antenna to transmit the transmission test signal of the preset frequency band to the wireless device to obtain the wireless receiving performance of the wireless device; or, controlling the wireless device to transmit the transmission test signal of the preset frequency band to the test antenna to obtain the wireless transmitting performance of the wireless device. In the embodiment, the tester loads the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the respective sub-band in the frequency domain, and therefore, it is also necessary to convert the transmission test signal corresponding to each sub-band in the frequency domain to the time domain. As an example, the inverse discrete Fourier transform can be used to convert the transmission test signal corresponding to each sub-band in the frequency domain to the time domain.

[0123] For reference Figure 8 The embodiment of the present application also provides a tester, which comprises an inverse matrix obtaining module 1001, a sub-band obtaining module 1002 and an inverse matrix loading module 1003.

[0124] The inverse matrix obtaining module 1001 is used to obtain the inverse matrix of the spatial transmission matrix corresponding to a plurality of sub-bands between the tester and the wireless device.

[0125] The sub-band obtaining module 1002 is used to obtain the expected test signal with the preset frequency band, and divide the expected test signal with the preset frequency band into the expected test signal corresponding to a plurality of sub-bands according to the frequency band; wherein the frequency range composed of the plurality of sub-bands is the frequency range corresponding to the preset frequency band.

[0126] The inverse matrix loading module 1003 is used to load the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the respective sub-band to obtain the transmission test signal corresponding to each sub-band, so as to establish a virtual cable connection between the tester and the wireless device and perform the over-the-air radiation test on the wireless device.

[0127] Each module in the tester provided by the embodiment corresponds to the method steps in the above-mentioned embodiments, and the specific implementation manner has been described in detail in the above-mentioned embodiments, which will not be described here again.

[0128] Those skilled in the art can understand that all or part of the functions of various methods in the above embodiments can be realized by hardware or by a computer program. When all or part of the functions in the above embodiments are realized by a computer program, the program can be stored in a computer readable storage medium, which can include a read-only memory, a random access memory, a magnetic disk, an optical disk, a hard disk, and the like. The above functions are realized by executing the program by a computer. For example, the program is stored in a memory of a device, and the above functions are realized by executing the program in the memory by a processor. In addition, when all or part of the functions in the above embodiments are realized by a computer program, the program can also be stored in a storage medium such as a server, another computer, a disk, an optical disk, a flash disk, or a mobile hard disk, and is saved in a memory of a local device by downloading or copying, or the system of the local device is updated, and the above functions are realized by executing the program in the memory by a processor.

[0129] The above application of specific examples to the present application is described, which is only used to help understand the present application and does not limit the present application. For those skilled in the art, according to the idea of the present application, a number of simple deductions, deformations or substitutions can be made.

Claims

1. An over-the-air radiation test system for a wireless device, the system comprising: The over-the-air radiation test system comprises a tester and at least two test antennas, wherein: The test antennas are used to establish a wireless communication link between the tester and the wireless device, so that the tester and the wireless device can communicate wirelessly; The tester is configured to: Obtain the inverse matrix of the spatial transmission matrix corresponding to multiple sub-bands between the tester and the wireless device; Obtain the expected test signal with a preset frequency band, and divide the expected test signal with the preset frequency band into expected test signals corresponding to multiple sub-bands according to the frequency band; wherein the frequency range composed of the multiple sub-bands is the frequency range corresponding to the preset frequency band; Load the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the corresponding sub-band to obtain the transmission test signal corresponding to each sub-band, so as to establish a virtual cable connection between the tester and the wireless device and perform over-the-air radiation test on the wireless device.

2. The over-the-air test system of claim 1, wherein, Obtaining the inverse matrix of the spatial transmission matrix corresponding to multiple sub-bands between the tester and the wireless device comprises: obtaining a downlink inverse matrix, and / or obtaining an uplink inverse matrix.

3. The over-the-air test system of claim 2, wherein, The obtaining of the downlink inverse matrix comprises: Obtaining the amplitude variation of each sub-band signal respectively transmitted by each transmitter port of the tester received by each receiver port of the wireless device; Obtaining the phase difference of each sub-band signal simultaneously transmitted by any two transmitter ports of the tester received by each receiver port of the wireless device; According to the amplitude variation and the phase difference corresponding to each sub-band signal, the inverse matrix of the spatial transmission matrix corresponding to multiple sub-bands between the tester and the receiver of the wireless device is obtained.

4. The over-the-air test system of claim 2, wherein, The obtaining of the uplink inverse matrix comprises: Obtaining the amplitude variation of each sub-band signal respectively transmitted by each transmitter port of the wireless device received by each receiver port of the tester; Obtaining the phase difference of each sub-band signal simultaneously transmitted by any two transmitter ports of the wireless device received by each receiver port of the tester; According to the amplitude variation and the phase difference corresponding to each sub-band signal, the inverse matrix of the spatial transmission matrix corresponding to multiple sub-bands between the transmitter of the wireless device and the tester is obtained.

5. The over-the-air test system of claim 1, wherein, Dividing the expected test signal with the preset frequency band into expected test signals corresponding to multiple sub-bands according to the frequency band comprises: Converting the expected test signal with the preset frequency band from the time domain to the frequency domain, and dividing the expected test signal with the preset frequency band into expected test signals corresponding to multiple sub-bands according to the frequency band in the frequency domain.

6. The over-the-air test system of claim 5, wherein, The expected test signals corresponding to the multiple sub-bands need to satisfy the following conditions: The phase difference of any two expected test signals corresponding to the sub-bands is less than a preset phase value.

7. The over-the-air test system of claim 5, wherein, Loading the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the corresponding sub-band to obtain the transmission test signal corresponding to each sub-band comprises: Load the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the corresponding sub-band to obtain the transmission test signal corresponding to each sub-band in the frequency domain; Convert the transmission test signal corresponding to each sub-band in the frequency domain to the time domain to obtain the transmission test signal corresponding to each sub-band.

8. A method of over-the-air radiation testing of a wireless device, the method comprising: The over-the-air radiation test method comprises: Obtaining the inverse matrix of the spatial transmission matrix corresponding to multiple sub-bands between the test instrument and the wireless device; Obtaining an expected test signal with a preset frequency band, and dividing the expected test signal with the preset frequency band into multiple sub-band corresponding expected test signals according to the frequency band; wherein the frequency range composed of the multiple sub-bands is the frequency range corresponding to the preset frequency band; Loading the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the corresponding sub-band to obtain the transmission test signal corresponding to each sub-band, so as to establish a virtual cable connection between the test instrument and the wireless device, and perform over-the-air radiation test on the wireless device.

9. The over-the-air radiation testing method of claim 8, wherein, The obtaining of the inverse matrix of the spatial transmission matrix corresponding to multiple sub-bands between the test instrument and the wireless device comprises: obtaining a downlink inverse matrix, and / or obtaining an uplink inverse matrix.

10. The over-the-air radiation testing method of claim 9, wherein, The obtaining of the downlink inverse matrix comprises: Obtaining the amplitude variation of each sub-band signal respectively transmitted by each transmitter port of the test instrument received by each receiver port of the wireless device; Obtaining the phase difference of each sub-band signal simultaneously transmitted by any two transmitter ports of the wireless device received by each receiver port of the wireless device; According to the amplitude variation and the phase difference corresponding to each sub-band signal, obtaining the inverse matrix of the spatial transmission matrix corresponding to multiple sub-bands between the test instrument and the receiver of the wireless device.

11. The over-the-air radiation testing method of claim 9, wherein, The obtaining of the uplink inverse matrix comprises: Obtaining the amplitude variation of each sub-band signal respectively transmitted by each transmitter port of the wireless device received by each receiver port of the test instrument; Obtaining the phase difference of each sub-band signal simultaneously transmitted by any two transmitter ports of the wireless device received by each receiver port of the test instrument; According to the amplitude variation and the phase difference corresponding to each sub-band signal, obtaining the inverse matrix of the spatial transmission matrix corresponding to multiple sub-bands between the transmitter of the wireless device and the test instrument.

12. The over-the-air radiation testing method of claim 8, wherein, The dividing of the expected test signal with the preset frequency band into multiple sub-band corresponding expected test signals according to the frequency band comprises: Converting the expected test signal with the preset frequency band from the time domain to the frequency domain, and dividing the expected test signal with the preset frequency band into multiple sub-band corresponding expected test signals according to the frequency band in the frequency domain.

13. The over-the-air test method of claim 12, wherein, The loading of the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the corresponding sub-band to obtain the transmission test signal corresponding to each sub-band comprises: Loading the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the corresponding sub-band to obtain the transmission test signal corresponding to each sub-band in the frequency domain; The transmission test signal corresponding to each sub-band in the frequency domain is converted from the frequency domain to the time domain to obtain the transmission test signal corresponding to each sub-band.

14. A tester characterized by, Comprise: An inverse matrix acquisition module, configured to acquire an inverse matrix of a spatial transmission matrix corresponding to a plurality of sub-bands between the test instrument and the wireless device; A sub-band acquisition module, configured to acquire an expected test signal having a preset frequency band, and divide the expected test signal having the preset frequency band into expected test signals corresponding to a plurality of sub-bands according to the frequency band; wherein the frequency range composed of the plurality of sub-bands is a frequency range corresponding to the preset frequency band; An inverse matrix loading module, configured to load the inverse matrix of the spatial transmission matrix corresponding to each sub-band into the expected test signal corresponding to the corresponding sub-band to obtain a transmission test signal corresponding to each sub-band, so as to establish a virtual cable connection between the test instrument and the wireless device and perform over-the-air radiation testing on the wireless device.

15. A computer readable storage medium, characterized in that, The medium stores a program, and the program can be executed by the processor to implement the over-the-air radiation testing method in any one of claims 8-13.

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