Disclosure of Invention
In view of the above, the present invention provides a method and a system for testing spatial radio frequency performance based on a multi-antenna system, which can test spatial radio frequency performance of a multi-antenna terminal.
In order to achieve the purpose, the technical scheme of the invention is realized as follows:
the invention provides a space radio frequency performance test method based on a multi-antenna system, which comprises the following steps:
the channel simulator outputs a path signal to the shunt device according to a signal input by the base station signal simulator;
the shunt device maps the path signal from the channel simulator to a test antenna in a full electric wave absorption darkroom according to a predetermined mapping relation;
the test antenna sends a space signal according to the path signal from the shunt device;
and the equipment to be tested receives the space signal, and then the space radio frequency performance analysis and display module analyzes and displays the space radio frequency performance of the equipment to be tested according to the space signal received by the equipment to be tested.
Wherein, the mapping relation between the path signal from the channel simulator and the test antenna is determined as follows: and determining the mapping relation between the path signal from the channel simulator and the test antenna according to the estimation of the direction of the arrival angle and the angle extension range of the path signal.
Wherein, the mapping relation between the path signal from the channel simulator and the test antenna is determined as follows: estimating an arrival angle of the path signal to obtain the direction of the arrival angle of the path signal and a corresponding angle expansion range; determining an angular spectrum extension range of the path signal according to the direction of the arrival angle of the path signal and a corresponding angular extension range; and determining that the path signal is mapped to the test antenna within the angular spectrum expansion range of the path signal.
In the above scheme, the number of the test antennas is not less than the number of the output paths of the channel simulator.
In the above scheme, the device to be tested is located at the center of the full electric wave absorption darkroom, and the test antenna is located on the circumference with the device to be tested as the center.
In the above scheme, the spatial radio frequency performance analysis and display module is implemented by a corresponding functional module in a test instrument/meter; or, the spatial radio frequency performance analysis and display module is a separate device.
In the above scheme, the mapping of the path signal to the test antenna is: and combining the sub-path signals of the path signals according to the number of the test antennas in the angular spectrum expansion range of the path signals, and sending the combined sub-path signals to the test antennas, wherein the number of the combined sub-path signals corresponds to the number of the test antennas in the angular spectrum expansion range of the path signals.
The invention also provides a space radio frequency performance test system based on the multi-antenna system, which comprises the following components: the system comprises a base station signal simulator, a channel simulator, a shunt device, a full-electric-wave absorption darkroom, a test antenna, equipment to be tested and a space radio-frequency performance analysis and display module; wherein,
the base station signal simulator is used for simulating a transmitting signal of a base station and outputting the transmitting signal to the channel simulator;
the channel simulator is used for outputting a path signal to the shunt device according to the signal input by the base station signal simulator;
the shunt device is used for mapping the path signal from the channel simulator to the test antenna in the full electric wave absorption darkroom according to a predetermined mapping relation;
the test antenna is positioned in the full electric wave absorption darkroom and used for sending a space signal according to a path signal from the shunt device;
the device to be tested is used for receiving the space signal sent by the test antenna;
and the space radio frequency performance analysis and display module is used for analyzing and displaying the space radio frequency performance of the equipment to be tested according to the space signal received by the equipment to be tested.
In the foregoing solution, the shunting device is further configured to determine a mapping relationship between the path signal from the channel simulator and the test antenna according to the estimation of the direction of the angle of arrival of the path signal and the angle spread range, specifically: estimating an arrival angle of the path signal to obtain the direction of the arrival angle of the path signal and a corresponding angle expansion range; determining an angular spectrum extension range of the path signal according to the direction of the arrival angle of the path signal and a corresponding angular extension range; and determining that the path signal is mapped to the test antenna within the angular spectrum expansion range of the path signal.
The invention relates to a space radio frequency performance test method and a system based on a multi-antenna system, which are characterized in that according to the estimation of the direction of the arrival angle and the angle extension range of a path signal, the path signal output by a channel simulator is mapped to a test antenna according to a certain rule, the test antenna sends the space signal according to the mapped path signal, and then the space radio frequency performance of equipment to be tested is analyzed and displayed according to the space signal received by the equipment to be tested, thereby realizing the test of the space radio frequency performance of a multi-antenna terminal.
Detailed Description
The basic idea of the invention is: according to the estimation of the direction of the arrival angle and the angle extension range of the path signal, the path signal output by the channel simulator is mapped to the test antenna according to a certain rule, the test antenna sends a space signal according to the mapped path signal, and then the space radio frequency performance of the equipment to be tested is analyzed and displayed according to the space signal received by the equipment to be tested.
Fig. 1 is a schematic flow chart of a spatial radio frequency performance testing method based on a multi-antenna system according to the present invention, and as shown in fig. 1, the spatial radio frequency performance testing method based on the multi-antenna system generally includes the following steps:
step 101: a base station signal simulator (BS simulator) simulates a transmission signal of a base station and outputs the transmission signal to a channel simulator.
For example, the base station signal simulator simulates the transmission signal of a base station and outputs M base station transmission signals, namely the transmission signals of M base station antennas.
Step 102: the channel simulator outputs the path signal to the branching device according to the signal input by the base station signal simulator.
Here, the M output signals of the base station simulator are input to the channel simulator to simulate the situation that the base station signal passes through the spatial channel, for example, the channel simulator outputs P signals according to the M output signals of the base station simulator, that is, the signal of each path is one output signal. It should be noted that, after the channel model used by the OTA is determined, the value of P may be determined.
In the present invention, the number N of test antennas is not less than the number P of channel simulator output paths (i.e., the number of paths (main paths, clusters) of the channel model used), and preferably, the number N of test antennas is equal to the number P of paths of the channel model. For example, based on the SCM, SCME, Winner I & II, the number of paths of the channel model is 6 or 8, so the preferred value of the number N of single-polarized test antennas is 6 or 8, for dual-polarized case, 2 antennas are configured at the same antenna position and are cross-polarized with each other, V & H or tilted X cross-polarized, and the preferred value of the number N of required test antennas should be 6 × 2 or 8 × 2, i.e. 12 or 16, and the number of test antennas can be equal to, but not limited to, this preferred value.
It should be noted that all the test antennas are located in the full wave absorbing dark room (such as the anechoic dark room and the wave absorbing dark room), the test antennas are located at different positions in the full wave absorbing dark room, and the test antennas transmit signals with certain time and space characteristics to test the multi-antenna device (terminal). Specifically, a Device Under Test (DUT) is generally located at the center of a full-wave absorption darkroom, and test antennas are located on a circumference centered on the DUT, which is to ensure that signals transmitted by the test antennas reach the DUT at the same time, so that the DUT receives signals from the space and processes the received signals, or the DUT processes the received signals after the signals are transmitted through a cable, and verifies the received signals, thereby completing the OTA test.
Step 103: the branching device maps the path signal from the channel simulator to the test antenna according to a predetermined mapping relationship.
The mapping of the path signal to the test antenna is: and combining the sub-path signals of the path signals according to the determined mapping relation, and mapping to the test antenna.
It should be noted that, generally, the mapping relationship between the path signal from the channel simulator and the test antenna is determined according to the estimation of the direction of the angle of arrival and the angular spread range of the path signal.
As described above, the number N of test antennas in the darkroom should be not less than (equal to or greater than) the number P of paths (same main path, same cluster) of the channel model used, and the optimized value of the number of test antennas is the number of paths of the channel model, so the following description will be made by taking as an example that the number of test antennas N may not be equal to the number P of paths.
In a multi-antenna system, each path generally consists of W sub-paths, W generally takes a value of 20, and since the number of sub-paths is too large, the operation of signal mapping is too complex, and therefore, the processing of sub-path combination is required. The merging can be performed by way of sub-path channel matrix element addition or vector addition, each path after merging contains 1 to K sub-paths, the preferred value of K is 3, P paths are still shared after sub-path merging, and each path contains 1 to K sub-paths.
The method for determining the mapping relation between the path signal from the channel simulator and the test antenna comprises the following steps:
estimating an arrival angle of the path signal to obtain the direction of the arrival angle of the path signal and a corresponding angle expansion range;
determining an angular spectrum extension range of the path signal according to the direction of the arrival angle of the path signal and a corresponding angular extension range;
and determining that the path signal is mapped to the test antenna within the angular spectrum expansion range of the path signal.
It can be seen that determining the mapping relationship between the path signals and the test antennas determines how to combine the sub-path signals of the path signals according to the number of the test antennas in the angular spectrum extension range of the path signals, and generally, the number of the combined sub-path signals corresponds to the number of the test antennas in the angular spectrum extension range of the path signals.
For example, if the angular spectrum spread range of a certain path is 20 degrees to 80 degrees, and there are 2 test antennas in the range, the W sub-path signals of the path are combined into 2 sub-path signals, and mapped to the test antennas in the darkroom for spatial signal transmission.
According to this method, the signals of P paths can be mapped to the test antenna in the darkroom, as shown in FIG. 2.
Step 104: the test antenna transmits a spatial signal according to the path signal from the branching device.
Step 105: the device to be tested receives the spatial signal.
Step 106: and the space radio frequency performance analysis and display module analyzes and displays the space radio frequency performance of the equipment to be tested according to the space signal received by the equipment to be tested.
Here, the DUT may receive a signal from the space, analyze the received signal, and send the analysis result to another device for display, or the DUT may send the received signal out through the cable line and analyze and display the received signal by the other device, thereby completing the OTA test. In other words, the spatial rf performance analysis and display module sometimes needs to perform performance index analysis, and sometimes only displays performance; in practical application, the spatial radio frequency performance analysis and display module can be directly completed by adopting a corresponding functional module in a test instrument/meter, namely: and directly utilizing a testing instrument/meter to perform performance analysis and performance display.
Fig. 3 is a schematic structural diagram of a space rf performance testing system based on a multi-antenna system according to the present invention, and as shown in fig. 3, the space rf performance testing system based on a multi-antenna system according to the present invention includes: a base station signal simulator 301, a channel simulator 302, a shunt device 303, a full-electric-wave absorption darkroom 304, a test antenna 305, a device to be tested 306 and a space radio-frequency performance analysis and display module 307; wherein,
a base station signal simulator 301 for simulating a transmission signal of a base station and outputting the transmission signal to a channel simulator 302;
a channel simulator 302 for outputting a path signal to the branching device 303 according to the signal input by the base station signal simulator;
a branching device 303 for mapping the path signal from the channel simulator to a test antenna 305 in a total wave absorption darkroom 304 according to a predetermined mapping relation; specifically, the path signal may be mapped to the corresponding test antenna by using a mapping relationship similar to that shown in fig. 2;
a test antenna 305 located in the full wave absorption darkroom 304 for transmitting a spatial signal according to the path signal from the branching device;
the device to be tested 306 is used for receiving the spatial signal sent by the test antenna;
the spatial radio frequency performance analyzing and displaying module 307 is configured to analyze and display the spatial radio frequency performance of the device to be tested according to the spatial signal received by the device to be tested 306.
The shunting device 303 is further configured to determine a mapping relationship between the path signal from the channel simulator and the test antenna according to the estimation of the direction of the angle of arrival of the path signal and the angle spread range, specifically:
estimating an arrival angle of the path signal to obtain the direction of the arrival angle of the path signal and a corresponding angle expansion range;
determining an angular spectrum extension range of the path signal according to the direction of the arrival angle of the path signal and a corresponding angular extension range;
and determining that the path signal is mapped to the test antenna within the angular spectrum expansion range of the path signal.
The number of test antennas 305 is not less than the number of output paths of the channel simulator 302.
The device under test 306 is located in the center of the full wave absorbing dark room 304 and the test antenna 305 is located on a circle centered on the device under test.
The spatial rf performance analyzing and displaying module 307 may be directly implemented by a corresponding functional module in a testing apparatus/meter, or may be located in a spatial rf performance testing system as a single device.
Fig. 4 is a schematic structural diagram of a spatial rf performance testing system based on a multi-antenna system according to an embodiment of the present invention, in which the number of test antennas is equal to the number of output paths of a channel simulator.
It can be seen that the invention provides a space radio frequency performance testing method and system based on a channel radio frequency simulator (channel simulator) and a full-electric-wave absorption darkroom, and specifies how to establish a testing environment, to realize the OTA test of an MIMO system (MIMO terminal), the processing of signals by the channel simulator, the relation between the antenna and the signals in the full-electric-wave absorption darkroom, and the like, and can effectively meet the requirements of MIMOOTA.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.