Radio frequency multichannel calibration method and system

Abstract

The invention discloses a radio frequency multi-channel calibration method and system, and the method comprises the steps: obtaining an independent test signal, converting the independent test signal into a radio frequency signal through a plurality of transmitting channels, and transmitting the radio frequency signal to a receiving channel; receiving the signals by a receiving channel to form a mixed signal, extracting gain, phase and time delay parameters of each transmitting channel from the mixed signal, and further performing parameter calibration on the transmitting channels; parameters of all transmitting channels can be measured at a time, the measuring precision and the calibration precision of the transmitting channels can be effectively improved, and the calibration time is shortened.

Description

Technical Field

[0001] The present invention relates to the field of radio frequency simulation technology, and more specifically, to a radio frequency multi-channel calibration method and system. Background Art

[0002] In radio stations, radars and other equipment, multiple transmit and receive channels can achieve MIMO transmission, beamforming and other capabilities, and achieve significant performance improvements. This system requires multiple channels to work together so that it can accurately control multiple signals to complete the expected functions. When there are deviations in the circuit parameters of each channel, including gain, phase, delay, etc., the system performance will be reduced. Therefore, before the multi-channel system is put into operation, it is generally necessary to perform channel calibration operations to make the gain, phase, delay and other parameters of each channel as consistent as possible.

[0003] In the existing multi-channel calibration technology, the calibration takes a long time. The calibration time of the channel is mainly consumed in the parameter measurement link, which increases with the increase of the number of channels. There are uncertainties in the phase measurement, and it is difficult to completely eliminate it. The test includes two mixing processes, and the phases of the two local oscillators will appear in the received signal and become part of the phase parameters output by the estimation module. If special measures are not taken to ensure that the initial phase of the local oscillator is exactly the same in each test, it is equivalent to a random fluctuation in the estimated phase parameter, and thus the purpose of accurate phase correction cannot be achieved. In practice, it is not easy to ensure that the initial phase of each test is exactly the same, or the cost required is high. Summary of the invention

[0004] In order to overcome the defects of the prior art that the calibration is time-consuming and the phase measurement accuracy and calibration accuracy are low, the present invention provides a radio frequency multi-channel calibration method and system, which can complete the measurement of all transmission channels at one time and effectively improve the measurement accuracy and calibration accuracy of phase parameters.

[0005] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0006] The present invention provides a radio frequency multi-channel calibration method, comprising:

[0007] Acquire multiple independent test signals;

[0008] Forming a plurality of radio frequency signals from a plurality of independent test signals through a plurality of transmission channels, and transmitting each radio frequency signal to a receiving channel;

[0009] A first mixed signal is formed based on each radio frequency signal received by the receiving channel, and the receiving channel obtains the gain, phase value and delay parameter of each transmitting channel according to the first mixed signal;

[0010] Parameters of each transmission channel are calibrated according to the gain, phase value and delay parameters of each transmission channel.

[0011] Preferably, the multiple transmission channels are arranged in parallel through homologous local oscillator units; the transmission channel includes a digital-to-analog converter, a first mixer, a first filter and an amplifier connected in sequence; the output end of the homologous local oscillator unit is connected to the input end of the first mixer of each transmission channel.

[0012] Preferably, the receiving channel comprises a measuring unit, a signal separation unit and a parameter estimation unit which are connected in sequence.

[0013] Preferably, the measuring unit comprises a second mixer, a second filter and an analog-to-digital converter connected in sequence;

[0014] The output end of the analog-to-digital converter is connected to the input end of the signal separation unit.

[0015] Preferably, the receiving channel obtains the gain, phase value and delay parameter of each transmitting channel according to the first mixed signal, including:

[0016] The first mixed signal is mixed, filtered and sampled by a measuring unit to obtain a second mixed signal;

[0017] The signal separation unit obtains a plurality of equivalent baseband signals after performing signal modeling, equation solving and signal reconstruction according to the second mixed signal and the test signal;

[0018] The parameter estimation unit obtains the gain, phase value and delay parameter of each transmission channel according to each test signal and its corresponding equivalent baseband signal.

[0019] Preferably, the fitting formula of the equivalent baseband signal is:

[0020]

[0021] Among them, k is the serial number of the sampled data, m is the number of transmission channels; x m is the test signal; H′ m (p) is the coefficient of the parameters of the equation system, and P is the number of coefficients.

[0022] Preferably, the parameter estimation unit obtains the gain, phase value and delay parameter of each transmission channel according to each test signal and its corresponding equivalent baseband signal, including:

[0023] The parameter estimation unit obtains the gain of each transmission channel according to the energy ratio of each test signal and its corresponding equivalent baseband signal;

[0024] The parameter estimation unit performs a cross-correlation operation on each test signal and its corresponding equivalent baseband signal to obtain the integer part of the delay difference between each test signal and its corresponding equivalent baseband signal, and then uses a fractional delay estimation method to obtain the fractional part of the delay difference, sums the integer part of the delay difference and the fractional part of the delay difference, and obtains the delay parameter of each transmission channel;

[0025] The parameter estimation unit performs time delay alignment on each test signal and its corresponding equivalent baseband signal to obtain a phase value of each transmission channel.

[0026] The present invention also provides a radio frequency multi-channel calibration system, comprising:

[0027] A signal acquisition module, which acquires multiple independent test signals;

[0028] A transmitting module converts multiple independent test signals into multiple radio frequency signals through multiple transmitting channels, and transmits each radio frequency signal to a receiving channel;

[0029] A receiving module, which forms a first mixed signal based on each radio frequency signal received by the receiving channel, and the receiving channel obtains the gain, phase value and delay parameter of each transmitting channel according to the first mixed signal;

[0030] The calibration module performs parameter calibration on each transmission channel according to the gain, phase value and delay parameters of each transmission channel.

[0031] The present invention also provides an electronic device, comprising:

[0032] one or more processors;

[0033] A memory for storing one or more programs;

[0034] When the one or more programs are executed by the one or more processors, the processors are enabled to implement the above method.

[0035] The present invention also provides a computer-readable storage medium containing a computer program, on which a computer program is stored, and the program implements the above method when executed by one or more processors.

[0036] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0037] The present invention proposes a radio frequency multi-channel calibration method and system, which obtains independent test signals, forms radio frequency signals through transmission channels and transmits them, forms mixed signals after reception, obtains gain, phase and delay parameters, and calibrates transmission channel parameters; the parameters of all transmission channels can be measured at one time, and the measurement accuracy and calibration accuracy of the transmission channels can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flow chart of the radio frequency multi-channel calibration method described in Example 1;

[0039] Figure 2 is a schematic diagram of the structure of the transmission channel described in Example 2;

[0040] Figure 3 This is a schematic diagram of the structure of the receiving channel described in Example 2;

[0041] Figure 4 This is a structural diagram of the channel parameter estimation error when N=64 in Example 3;

[0042] Figure 5 This is a schematic diagram of the structure of the radio frequency multi-channel calibration system described in Example 3;

[0043] Figure 6 This is a schematic diagram of the structure of a computer device described in Example 4. DETAILED DESCRIPTION

[0044] The drawings are for illustrative purposes only and should not be construed as limiting the present patent;

[0045] In order to better illustrate the present embodiment, some parts in the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product;

[0046] It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0047] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0048] Example 1

[0049] This embodiment provides a radio frequency multi-channel calibration method, such as Figure 1 As shown, including:

[0050] Acquire multiple independent test signals;

[0051] Forming a plurality of radio frequency signals from a plurality of independent test signals through a plurality of transmission channels, and transmitting each radio frequency signal to a receiving channel;

[0052] A first mixed signal is formed based on each radio frequency signal received by the receiving channel, and the receiving channel obtains the gain, phase value and delay parameter of each transmitting channel according to the first mixed signal;

[0053] Parameters of each transmission channel are calibrated according to the gain, phase value and delay parameters of each transmission channel.

[0054] This embodiment obtains an independent test signal, forms a radio frequency signal through a transmission channel and transmits it, forms a mixed signal after reception, obtains gain, phase and delay parameters, and calibrates the transmission channel parameters; it can measure the parameters of all transmission channels at one time, and can effectively improve the measurement accuracy and calibration accuracy of the transmission channel.

[0055] Example 2

[0056] This embodiment provides a radio frequency multi-channel calibration method, including:

[0057] Acquire multiple independent test signals;

[0058] Forming a plurality of radio frequency signals from a plurality of independent test signals through a plurality of transmission channels, and transmitting each radio frequency signal to a receiving channel;

[0059] A first mixed signal is formed based on each radio frequency signal received by the receiving channel, and the receiving channel obtains the gain, phase value and delay parameter of each transmitting channel according to the first mixed signal;

[0060] Parameters of each transmission channel are calibrated according to the gain, phase value and delay parameters of each transmission channel.

[0061] like Figure 2 As shown, the multiple transmission channels are arranged in parallel through homologous local oscillator units; the transmission channel includes a digital-to-analog converter, a first mixer, a first filter and an amplifier connected in sequence; the output end of the homologous local oscillator unit is connected to the input end of the first mixer of each transmission channel.

[0062] like Figure 3 As shown, the receiving channel includes a measuring unit, a signal separation unit and a parameter estimation unit which are connected in sequence.

[0063] The measuring unit comprises a second mixer, a second filter and an analog-to-digital converter connected in sequence;

[0064] The output end of the analog-to-digital converter is connected to the input end of the signal separation unit.

[0065] The receiving channel obtains the gain, phase value and delay parameter of each transmitting channel according to the first mixed signal, including:

[0066] The first mixed signal is mixed, filtered and sampled by a measuring unit to obtain a second mixed signal;

[0067] The signal separation unit obtains a plurality of equivalent baseband signals after performing signal modeling, equation solving and signal reconstruction according to the second mixed signal and the test signal;

[0068] The parameter estimation unit obtains the gain, phase value and delay parameter of each transmission channel according to each test signal and its corresponding equivalent baseband signal.

[0069] The fitting formula of the equivalent baseband signal is:

[0070]

[0071] Among them, k is the serial number of the sampled data, m is the number of transmission channels; x m is the test signal; H′ m (p) is the coefficient of the parameters of the equation system, and P is the number of coefficients.

[0072] The parameter estimation unit obtains the gain, phase value and delay parameter of each transmission channel according to each test signal and its corresponding equivalent baseband signal, including:

[0073] The parameter estimation unit obtains the gain of each transmission channel according to the energy ratio of each test signal and its corresponding equivalent baseband signal;

[0074] The parameter estimation unit performs a cross-correlation operation on each test signal and its corresponding equivalent baseband signal to obtain the integer part of the delay difference between each test signal and its corresponding equivalent baseband signal, and then uses a fractional delay estimation method to obtain the fractional part of the delay difference, sums the integer part of the delay difference and the fractional part of the delay difference, and obtains the delay parameter of each transmission channel;

[0075] The parameter estimation unit performs time delay alignment on each test signal and its corresponding equivalent baseband signal to obtain a phase value of each transmission channel.

[0076] This embodiment obtains independent test signals, converts them into RF signals through multiple transmission channels, and transmits them to the receiving channel. The receiving channel receives these signals to form a mixed signal, and extracts the gain, phase and delay parameters of each transmission channel from it, and then calibrates the parameters of the transmission channel; it can measure the parameters of all transmission channels at one time, which can effectively improve the measurement accuracy and calibration accuracy of the transmission channel.

[0077] In a specific embodiment, the system has N transmission channels to be tested, namely channel 1, channel 2, ..., channel N. When the test instruction is activated, the N channels simultaneously transmit N unrelated baseband test signals x1, x2, ..., xN to form radio frequency signals s1, s2, ..., sN.

[0078] The signal receiving probe of the measurement module is placed on the main radiation path of the above-mentioned RF signal to obtain a mixed signal sa containing s1, s2, ..., sN, which is then subjected to mixing, filtering, ADC sampling and other steps to become a mixed baseband signal ya.

[0079] The signal separation module recovers the equivalent baseband signals y1, y2, …, yN of s1, s2, …, sN based on the mixed signal ya and the test signals x1, x2, …, xN through signal modeling, equation solving, signal reconstruction and other operations.

[0080] The parameter estimation module estimates the gain, phase, and delay parameters of channel m using xm and ym, where m = 1, 2, ..., N.

[0081] The specific testing principles are as follows.

[0082] The ym is approximated by the following formula:

[0083]

[0084] The mixed signal ya is the sum of these components:

[0085]

[0086] Assume that the length of the test signal is L samples, and L>N×P. Substitute the known x1(k), x2(k), ..., xN(k), and the measured ya(k), k = 1, 2, ..., L, into equation (2) to form the equation about N×P unknown quantities H m (p) is a linear system of equations.

[0087] The linear equations are solved based on the least squares error and other criteria to obtain the approximate solution H' m (p)≈H m (p).

[0088] The separated baseband signal is reconstructed using the following formula:

[0089]

[0090] Finally, the parameters of channel m are obtained from xm and ym as follows:

[0091] According to the energy ratio of xm and ym, the channel gain gm is obtained;

[0092] Through cross-correlation operation, the integer part of the delay difference between xm and ym is obtained, and then the decimal part of the delay difference is obtained by using the fractional delay estimation method. The sum of the two is the delay value dm between xm and ym;

[0093] Align xm and ym in terms of time delay, and then obtain the phase value pm of xm and ym.

[0094] In the channel calibration phase, assuming that channel 1 is used as the reference channel, the deviation of the gain, phase, and delay parameters of channel m relative to channel 1 is calculated first, and then the parameters of channel m are adjusted. In this way, the calibration process of the multi-channel system is completed one by one, such as Figure 4 As shown, it is the channel parameter estimation error when N=64.

[0095] Example 3

[0096] This embodiment provides a radio frequency multi-channel calibration system, such as Figure 5 As shown, including:

[0097] A signal acquisition module, which acquires multiple independent test signals;

[0098] A transmitting module converts multiple independent test signals into multiple radio frequency signals through multiple transmitting channels, and transmits each radio frequency signal to a receiving channel;

[0099] A receiving module, which forms a first mixed signal based on each radio frequency signal received by the receiving channel, and the receiving channel obtains the gain, phase value and delay parameter of each transmitting channel according to the first mixed signal;

[0100] The calibration module performs parameter calibration on each transmission channel according to the gain, phase value and delay parameters of each transmission channel.

[0101] Example 4

[0102] This embodiment provides a computer device, such as Figure 6 As shown, at least one processor 01 , at least one communication interface 02 , at least one memory 03 and at least one communication bus 04 .

[0103] In the embodiment of the present application, the number of the processor 01 , the communication interface 02 , the memory 03 , and the communication bus 04 is at least one, and the processor 01 , the communication interface 02 , and the memory 03 communicate with each other through the communication bus 04 .

[0104] Processor 01 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. Processor 01 may be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA). Processor 01 may also include a main processor and a coprocessor. The main processor is a processor for processing data in an awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in a standby state. In some embodiments, processor 01 may be integrated with a graphics processing unit (GPU), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, processor 01 may also include an artificial intelligence (AI) processor, which is used to process computing operations related to machine learning.

[0105] The memory 03 may include one or more computer-readable storage media, which may be non-transitory. The memory 03 may also include a high-speed random access memory and a non-volatile memory, such as one or more disk storage devices and flash memory storage devices.

[0106] The memory 03 stores a program, and the processor 01 can call the program stored in the memory 03, and the program is used to execute the steps of the radio frequency multi-channel calibration method described in embodiment 1 or 2.

[0107] The same or similar reference numerals correspond to the same or similar components;

[0108] The terms used in the drawings to describe positional relationships are only used for illustrative purposes and should not be construed as limiting this patent;

[0109] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A radio frequency multi-channel calibration method, characterized in that: include: Acquire multiple independent test signals; Forming a plurality of radio frequency signals from a plurality of independent test signals through a plurality of transmission channels, and transmitting each radio frequency signal to a receiving channel; A first mixed signal is formed based on each radio frequency signal received by the receiving channel, and the receiving channel obtains the gain, phase value and delay parameter of each transmitting channel according to the first mixed signal; Parameters of each transmission channel are calibrated according to the gain, phase value and delay parameters of each transmission channel.

2. The radio frequency multi-channel calibration method according to claim 1, characterized in that: The multiple transmission channels are arranged in parallel through homologous local oscillator units; the transmission channel includes a digital-to-analog converter, a first mixer, a first filter and an amplifier connected in sequence; the output end of the homologous local oscillator unit is connected to the input end of the first mixer of each transmission channel.

3. The radio frequency multi-channel calibration method according to claim 1, characterized in that: The receiving channel includes a measuring unit, a signal separation unit and a parameter estimation unit which are connected in sequence.

4. The radio frequency multi-channel calibration method according to claim 3, characterized in that: The measuring unit comprises a second mixer, a second filter and an analog-to-digital converter connected in sequence; The output end of the analog-to-digital converter is connected to the input end of the signal separation unit.

5. The radio frequency multi-channel calibration method according to claim 3, characterized in that: The receiving channel obtains the gain, phase value and delay parameter of each transmitting channel according to the first mixed signal, including: The first mixed signal is mixed, filtered and sampled by a measuring unit to obtain a second mixed signal; The signal separation unit obtains a plurality of equivalent baseband signals after performing signal modeling, equation solving and signal reconstruction according to the second mixed signal and the test signal; The parameter estimation unit obtains the gain, phase value and delay parameter of each transmission channel according to each test signal and its corresponding equivalent baseband signal.

6. The radio frequency multi-channel calibration method according to claim 5, characterized in that: The fitting formula of the equivalent baseband signal is: Among them, k is the serial number of the sampled data, m is the number of transmission channels; x m is the test signal; H ′ m (p) is the coefficient of the parameters of the equation system, and P is the number of coefficients.

7. The radio frequency multi-channel calibration method according to claim 5, characterized in that: The parameter estimation unit obtains the gain, phase value and delay parameter of each transmission channel according to each test signal and its corresponding equivalent baseband signal, including: The parameter estimation unit obtains the gain of each transmission channel according to the energy ratio of each test signal and its corresponding equivalent baseband signal; The parameter estimation unit performs a cross-correlation operation on each test signal and its corresponding equivalent baseband signal to obtain the integer part of the delay difference between each test signal and its corresponding equivalent baseband signal, and then uses a fractional delay estimation method to obtain the fractional part of the delay difference, sums the integer part of the delay difference and the fractional part of the delay difference, and obtains the delay parameter of each transmission channel; The parameter estimation unit performs time delay alignment on each test signal and its corresponding equivalent baseband signal to obtain a phase value of each transmission channel.

8. A radio frequency multi-channel calibration system, characterized in that: include: A signal acquisition module, which acquires multiple independent test signals; A transmitting module converts multiple independent test signals into multiple radio frequency signals through multiple transmitting channels, and transmits each radio frequency signal to a receiving channel; A receiving module, which forms a first mixed signal based on each radio frequency signal received by the receiving channel, and the receiving channel obtains the gain, phase value and delay parameter of each transmitting channel according to the first mixed signal; The calibration module performs parameter calibration on each transmission channel according to the gain, phase value and delay parameters of each transmission channel.

9. An electronic device, characterized in that: include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the processors are enabled to implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium containing a computer program, wherein the computer program is stored thereon, characterized in that: When the program is executed by one or more processors, the method according to any one of claims 1 to 7 is implemented.

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