Uplink channel signal time delay calibration method and system adopting far-field calibration system
By calculating the uplink channel signal delay through the far-field calibration system, the difficult problem of uplink channel signal calibration in the antenna array is solved, and accurate delay calibration and simplified system design are achieved.
Patent Information
- Application Number
- CN202510941083.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-09
- Publication Date
- 2025-09-30
AI Technical Summary
It is difficult to effectively calibrate the uplink channel signal delay in the antenna array with existing technologies, resulting in poor signal synthesis effect.
A far-field calibration system is used to generate reference signals and modulation signals through the uplink channel calibration unit. The far-field calibration system is used to convert frequencies and demodulate signal envelopes, combined with phase difference calculation, to achieve calibration of the uplink channel signal delay.
The accurate calibration of the uplink channel signal delay of the antenna array system is achieved, which simplifies the system design, reduces costs, and facilitates automated operation.
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Figure CN120729440A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of antenna array technology, and in particular to a method and system for calibrating uplink channel signal delay using a far-field calibration system. Background Art
[0002] Antenna arrays combine signals from multiple antennas to improve the signal-to-noise ratio (SNR) of received or transmitted signals. Due to their flexibility and low engineering costs, antenna arrays have gained increasing attention in deep space exploration in recent years, becoming a hot area of research for novel antenna systems.
[0003] Signal synthesis in an antenna array typically uses delay compensation to align the signal delays of each antenna in the array to the same reference point, thereby increasing the signal-to-noise ratio of the received or transmitted signal. The signal delay of each antenna in the array consists of two components: the signal delay in the spatial path and the signal delay in the antenna's own uplink and downlink channels. Therefore, a key technical issue in the implementation of antenna arrays is how to calibrate the signal delays of the uplink and downlink channels of each antenna in the array. To calibrate the signal delay of the antenna's downlink channel, two antennas are typically used to simultaneously receive signals transmitted from the same target source. The signals received by the two antennas are compared in a correlation manner, and the relative delay of the two signals is obtained using the phase slope estimation method. The spatial delay between the antennas and the target source is then deducted to obtain the relative signal delay of the downlink channels of the two antennas. However, calibrating the signal delay of the antenna's uplink channel is difficult because multiple antennas transmitting uplink signals simultaneously will cause mutual interference. Summary of the Invention
[0004] In view of this, the present application provides an uplink channel signal delay calibration method and system using a far-field calibration system to realize the uplink array function of the antenna array system.
[0005] The present application discloses a method for calibrating uplink channel signal delay using a far-field calibration system, which includes: The uplink channel calibration unit generates an uplink channel calibration reference signal and an uplink channel calibration modulated signal and sends them to the reference antenna and the antenna to be calibrated, respectively. The reference antenna is any antenna in the antenna array, and the antenna to be calibrated is any antenna in the antenna array except the reference antenna. The uplink channel calibration reference signal is the uplink signal, and the uplink channel calibration modulated signal is the uplink signal after phase modulation. The reference antenna and the antenna to be calibrated send the signals they receive to the far-field calibration system; The far-field calibration system converts the received signal into a downlink signal and sends it to the uplink channel calibration unit through the reference antenna and the antenna to be calibrated; The uplink channel calibration modulation signal demodulates the received signal sent by the far-field calibration system into a signal envelope, and obtains the relative phase difference of the uplink channel signal based on the signal envelope; According to the relative phase difference of the uplink channel signal, the phase difference caused by the difference in the uplink channel of the antenna to be calibrated relative to the reference antenna is obtained; Different uplink frequency points are selected to calibrate the relative phase difference of the uplink channel of the antenna to be calibrated relative to the reference antenna, and the relative signal delay difference of the uplink channel of the antenna to be calibrated relative to the reference antenna is obtained.
[0006] Furthermore, the digitally controlled oscillator in the uplink channel calibration signal generator in the uplink channel calibration unit generates an uplink signal according to the uplink frequency set by the system, and divides the uplink signal into two paths, one of which is directly sent to the reference antenna as the uplink channel calibration reference signal, and the other path passes through the uplink channel calibration signal modulation unit in the uplink channel calibration signal generator; the uplink channel calibration signal modulation unit performs phase modulation on the uplink signal according to the phase value to obtain the uplink channel calibration modulated signal and sends it to the antenna to be calibrated; The uplink channel calibration reference signal of the reference antenna is:
[0007] The uplink channel calibration modulation signal after phase modulation of the antenna to be calibrated is:
[0008] in, It is the phase difference between the reference antenna and the antenna to be calibrated due to the spatial path difference; It is the phase difference between the reference antenna and the antenna to be calibrated due to the difference in the antenna's own uplink channel; The amplitude of the uplink signal received by the reference antenna at the antenna aperture for calibration; and is a slowly changing phase value, is the angular frequency, For time, is the frequency.
[0009] Furthermore, the far-field calibration system includes a calibration antenna; taking the signal transmitted by the reference antenna received by the calibration antenna aperture as a reference, and the signal of the antenna to be calibrated The sum of , obtain the composite signal of the signals transmitted by the reference antenna and the antenna to be calibrated on the calibration antenna aperture and regard it as an amplitude modulated signal ;
[0010] in, is the angular frequency, For time, is the frequency, It is the phase difference between the reference antenna and the antenna to be calibrated due to the spatial path difference; It is the phase difference between the reference antenna and the antenna to be calibrated due to the difference in the antenna's own uplink channel; The uplink signal amplitude of the reference antenna received by the calibration antenna aperture; is a slowly changing phase value, is the angular frequency; The calibration antenna in the far-field calibration system converts the synthesized signal into a downlink signal and then sends it to the reference antenna and the antenna to be calibrated; after receiving the synthesized downlink signal, the reference antenna and the antenna to be calibrated send it to the channel selection unit in the uplink channel calibration unit; The channel selection unit selects one channel from the downlink signals received from the reference antenna and the antenna to be calibrated, that is, the composite signal, and sends it to the dual-channel phase calibration unit in the uplink channel calibration unit for phase calibration processing; the dual-channel phase calibration unit calibrates the channel phase and sends the phase value to the uplink channel signal generator in the uplink channel calibration unit.
[0011] Furthermore, the signal amplitude demodulation unit in the dual-channel phase calibration unit receives the composite signal transmitted by the calibration antenna and transmitted by the reference antenna or the antenna to be calibrated and demodulates the signal envelope therefrom; The phase generator in the dual-channel phase correction unit generates a slowly varying phase value , and divide it into two paths, one path is sent to the uplink channel calibration signal generator to modulate the uplink signal of the antenna to be calibrated, and the other path is sent to the reference signal generator to generate a reference signal for phase demodulation :
[0012] The dual-channel phase correction unit first locks the signal after the automatic gain control AGC through the phase-locked loop PLL, and uses the reference signal output by the phase-locked loop in the amplitude estimation unit to obtain the slowly changing envelope of the input signal using a coherent method; the amplitude estimation unit is controlled by the timing pulse sent by the phase generation unit. After receiving each timing pulse, it waits until a fixed signal transmission delay value is reached, and estimates the signal amplitude before the next timing pulse arrives, and finally obtains the signal envelope. for: .
[0013] Furthermore, the timer in the phase generating unit generates a timing pulse according to a timing time interval preset by the system and sends it to the phase generator in the phase generating unit; The phase generator generates a phase value through the received timing pulse and divides it into two paths, one path is directly sent to the uplink channel calibration signal generator, and the other path is sent to the reference signal generator to generate a reference signal for phase demodulation.
[0014] Furthermore, the timer also sends a timing pulse to the signal amplitude demodulation unit to control the envelope of the synthesized signal; the period of the timing pulse preset by the system is greater than the signal transmission and envelope demodulation time.
[0015] Furthermore, in the signal amplitude demodulation unit, the synthesized signal is locked by a phase-locked loop after automatic gain control, and the amplitude estimation unit uses a reference signal output by the phase-locked loop to obtain a signal envelope of the synthesized signal.
[0016] Furthermore, the amplitude estimation unit is controlled by the timing pulse sent by the phase generation unit. After receiving each timing pulse, it waits for a fixed signal transmission delay value and estimates the signal amplitude before the next timing pulse arrives to obtain the signal envelope.
[0017] Furthermore, the phase demodulation unit in the dual-channel phase correction unit demodulates the reference signal by adopting a phase estimation method based on conjugate operation. The real part of and signal envelope The phase difference between ,in, is the phase difference caused by the spatial path difference between the antenna to be calibrated and the reference antenna; The phase difference is caused by the difference in the uplink channel of the antenna to be calibrated relative to the reference antenna; According to the position information of the reference antenna and the antenna to be calibrated, the position information of the far-field calibration antenna and the frequency of the calibration signal, the phase difference caused by the spatial path difference is obtained. ,from Subtract , we can get the phase difference caused by the difference in the uplink channel of the antenna to be calibrated relative to the reference antenna .
[0018] Furthermore, the uplink channel relative phase difference of the antenna to be calibrated relative to the reference antenna is calibrated with the uplink frequency point. , use the uplink frequency point to calibrate the uplink channel relative phase difference of the antenna to be calibrated relative to the reference antenna According to the phase slope estimation method, the relative delay difference of the uplink signal of the antenna to be calibrated relative to the reference antenna is obtained. .
[0019] The present application also discloses an uplink channel signal delay calibration system using a far-field calibration system, which is suitable for the above-mentioned uplink channel signal delay calibration method using a far-field calibration system, and includes an uplink channel calibration unit, an antenna array and a far-field calibration system; the uplink channel calibration unit is composed of an uplink channel calibration signal generator, a dual-channel phase calibration unit and a channel selection unit; the channel selection unit is connected to the uplink channel calibration signal generator through the dual-channel phase calibration unit; the uplink channel signal generator is composed of a digitally controlled oscillator and an uplink channel calibration signal modulation unit; the digitally controlled oscillator is connected to the uplink channel calibration signal modulation unit.
[0020] Furthermore, the dual-channel phase correction unit includes a signal amplitude demodulation unit, a phase generation unit, and a phase demodulation unit; the signal amplitude demodulation unit is respectively connected to the phase generation unit and the phase demodulation unit; the signal amplitude demodulation unit is connected to the phase generation unit; the phase generation unit includes a phase generator, a timer, and a reference signal generator; the phase generation is respectively connected to the timer and the reference signal generator; the signal amplitude demodulation unit includes a phase-locked loop and an amplitude estimation unit; the phase-locked loop is connected to the amplitude estimation unit.
[0021] Due to the adoption of the above technical solution, this application has the following advantages: 1. Solve the problem of antenna array calibration antenna uplink channel signal delay. This application uses a far-field calibration antenna and uplink signal phase modulation to estimate the relative uplink signal channel delay of each antenna in the antenna array. Based on this, the antenna array uplink array can be formed, solving a key problem in array antenna system design.
[0022] 2. Simple implementation, low resource usage, and reduced system design costs. This application does not require complex circuits and is relatively simple to implement. It utilizes only existing system equipment, eliminating the need for additional equipment. It also implements the uplink signal channel relative delay detection function of the antenna array system through a software algorithm, facilitating automated operation and reducing system design costs.
[0023] 3. This application is easy and quick to operate, and is convenient for system design. The operation process of this application is simple, and the delay calibration process can be controlled by software, which is convenient for implementation in large-scale antenna arrays. The method proposed in this application aims to provide a simple, reliable and easy-to-implement method for calibrating the signal delay of the uplink channel of each antenna in the antenna array system. This method does not require any external equipment, which facilitates the design of antenna array systems that meet the index requirements in engineering practice. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.
[0025] Figure 1 This is a schematic diagram of using a far-field calibration system to calibrate the relative delay difference of the uplink channels of two antennas in an embodiment of the present application.
[0026] Figure 2 Schematic diagram of the composition of the far-field calibration system of an embodiment of the present application.
[0027] Figure 3 It is a schematic diagram of the composition of the uplink channel calibration unit of an embodiment of the present application.
[0028] Figure 4 It is a schematic diagram of the composition of the uplink channel signal generator in the uplink channel calibration unit of an embodiment of the present application.
[0029] Figure 5 It is a schematic diagram of the uplink composite signal received by the calibration antenna receiving end of an embodiment of the present application.
[0030] Figure 6 It is a schematic diagram of the structure of the dual-channel phase calibration unit in the uplink channel calibration unit of an embodiment of the present application.
[0031] Figure 7 Schematic diagram of the structure of the signal amplitude demodulation unit in the dual-channel phase correction unit of an embodiment of the present application.
[0032] Figure 8 3 is a schematic diagram of an input signal envelope obtained by demodulation by a signal amplitude demodulation unit according to an embodiment of the present application.
[0033] Figure 9 Schematic diagram of the structure of the phase generating unit in the dual-channel phase correction unit of an embodiment of the present application.
[0034] Figure 10 is a schematic diagram of a reference signal generated by a phase generating unit according to an embodiment of the present application.
[0035] Figure 11 This is a schematic diagram of obtaining the uplink signal phase difference based on the envelope of the incoming signal and the reference signal according to an embodiment of the present application.
[0036] Figure 12 This is a flow chart of calibrating the relative delay of the uplink channel signal of antenna B using antenna A as a reference according to an embodiment of the present application. DETAILED DESCRIPTION
[0037] The present application is further described with reference to the accompanying drawings and embodiments. The embodiments described are only a part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of the embodiments of the present application.
[0038] A crucial technical challenge in implementing uplink antenna array systems is calibrating the signal delay of each antenna in the array. Traditional methods for calibrating antenna uplink delay typically rely on indirect comparisons of transmit and receive timings or wired near-field calibration. These methods often fail to meet engineering requirements for uplink delay calibration accuracy.
[0039] To solve the above technical problems, see Figure 1 Based on the characteristics of antenna uplink signals, this application proposes an embodiment of an uplink channel signal delay calibration method using a far-field calibration system, which includes: The uplink channel calibration unit generates an uplink channel calibration reference signal and an uplink channel calibration modulated signal and sends them to the reference antenna and the antenna to be calibrated, respectively. The reference antenna is any antenna in the antenna array, and the antenna to be calibrated is any antenna in the antenna array except the reference antenna. The uplink channel calibration reference signal is the uplink signal, and the uplink channel calibration modulated signal is the uplink signal after phase modulation. The reference antenna and the antenna to be calibrated send the signals they receive to the far-field calibration system; The far-field calibration system converts the received signal into a downlink signal and sends it to the uplink channel calibration unit through the reference antenna and the antenna to be calibrated; The uplink channel calibration modulation signal demodulates the received signal sent by the far-field calibration system into a signal envelope, and obtains the relative phase difference of the uplink channel signal based on the signal envelope; According to the relative phase difference of the uplink channel signal, the phase difference caused by the difference in the uplink channel of the antenna to be calibrated relative to the reference antenna is obtained; The relative phase difference of the uplink channel of the antenna to be calibrated relative to the reference antenna is calibrated at different uplink frequency points to obtain the relative signal delay difference of the uplink channel of the antenna to be calibrated relative to the reference antenna.
[0040] The method of the present application is simple, reliable and easy to implement, and can meet the demand for antenna uplink channel signal delay calibration in engineering practice. By using this method, an antenna array system that meets the index requirements can be designed in engineering practice.
[0041] In the examples of this application, see Figure 1, using a calibration system set up in the far field to calibrate the relative signal delay difference of the uplink channel of each antenna in the antenna array, select one antenna in the antenna array as a reference antenna, and calibrate the relative signal delay difference of the uplink channel of other antennas relative to the reference. Figure 1 As shown in the figure, with antenna A as a reference, the uplink channel calibration unit and the far-field calibration system are used to calibrate the relative delay difference of the uplink channel signal of antenna B.
[0042] In the examples of this application, see Figure 2 , the distance between the far-field calibration system and the antenna array meets the far-field conditions for signal reception and transmission. Figure 2 As shown in Figure 1, the far-field calibration system consists of a calibration antenna, an uplink amplifier, a frequency converter, and a downlink amplifier. The far-field calibration system first receives the uplink signal transmitted by the antenna array through the calibration antenna, amplifies it, and then sends it to the frequency converter to convert the received uplink signal from the uplink frequency to the downlink frequency. After downlink amplification, the signal is then sent to the calibration antenna for transmission.
[0043] In the examples of this application, see Figure 3 , the uplink channel calibration unit generates two uplink signals and sends them to the reference antenna A and the antenna to be calibrated B respectively, and receives the downlink signals received by antennas A and B at the same time. Figure 3 As shown, the uplink channel calibration unit consists of three parts: an uplink channel calibration signal generator, a dual-channel phase calibration unit, and a channel selection unit. The uplink channel calibration signal generator generates two uplink signals and sends them to antennas A and B. The channel selection unit selects one downlink signal from the downlink signals received by antennas A and B and sends it to the dual-channel phase calibration unit for phase calibration. The dual-channel phase calibration unit will also send one phase value while calibrating the channel phase. Provides the upstream channel signal generator to modulate the upstream signal.
[0044] In the examples of this application, see Figure 4 and Figure 5 The uplink channel signal generator generates two uplink signals according to the uplink frequency set by the system, one of which is the reference signal for uplink channel calibration, and the other is the phase value sent The modulated uplink channel calibration modulation signal. Figure 4 As shown in the figure, the uplink channel signal generator consists of two parts: NCO (digital controlled oscillator) and the uplink channel calibration signal modulation unit. The NCO is based on the uplink frequency set by the system. Generate an uplink signal, split the uplink signal into two paths, one of which is directly sent to the reference antenna A as the uplink channel calibration reference signal The other signal modulation unit that has been calibrated through the uplink channel is based on the phase value sent After phase modulation, it is sent to antenna B as the uplink channel calibration modulation signal , where the angular frequency ; is the amplitude of the transmitted signal.
[0045] Now let’s consider the signal received at the aperture of the far-field calibration antenna. Taking the signal transmitted by the reference antenna A received at the aperture of the calibration antenna as the reference, let the signal of the reference antenna A received at the aperture of the calibration antenna be:
[0046] The signal received by antenna B at the calibration antenna aperture is:
[0047] in, is the phase difference between antennas A and B due to the spatial path difference; It is the phase difference between antennas A and B due to the difference in the uplink channels of the antennas themselves. To calibrate the signal amplitude of antenna A received at the antenna aperture.
[0048] When the phase value When the phase value is a slowly changing value, the composite signal of the antenna A and B transmission signals on the calibration antenna surface can be Considered as an amplitude modulated signal, it is recorded as:
[0049] That is Figure 5 As shown, the envelope of the signal is a slow-changing signal .
[0050] In the examples of this application, see Figure 6 ,like Figure 6 As shown, the dual-channel phase calibration unit receives the uplink channel calibration signal (synthetic signal) forwarded by the far-field calibration system. ), first demodulate the signal envelope through the signal amplitude demodulation unit The phase demodulation unit generates a reference signal based on the phase generation unit. From the signal envelope Demodulate the relative phase difference of the uplink channel signal , and the phase value is generated by the phase generating unit The uplink channel calibration signal generator is sent to modulate the uplink signal of the antenna to be calibrated.
[0051] See Figure 7 and Figure 8 ,like Figure 7As shown, in the phase generating unit, the timer generates a timing pulse according to the system preset timing time interval, through which the phase generator generates a slowly changing phase value. , and divide it into two paths, one path is sent to the uplink channel calibration signal generator to modulate the uplink signal of the antenna to be calibrated, and the other path is sent to the reference signal generator to generate a reference signal for phase demodulation :
[0052] Real part of the reference signal like Figure 8 shown.
[0053] The timer also sends a timing pulse to the signal amplitude demodulation unit to control the envelope of the demodulated signal. The period of the timing pulse preset by the system must be greater than the signal transmission and envelope demodulation time.
[0054] In the examples of this application, see Figure 9 and Figure 10 ,like Figure 9 As shown in the figure, the signal amplitude demodulation unit locks the signal after AGC (automatic gain control) through PLL (phase-locked loop), and the amplitude estimation unit uses the reference signal output by the phase-locked loop to obtain the slowly changing envelope of the input signal using a coherent method. The amplitude estimation unit is controlled by the timing pulse sent by the phase generation unit. After receiving each timing pulse, it waits until a fixed signal transmission delay value is reached and estimates the signal amplitude before the next timing pulse arrives, finally obtaining the signal envelope. for:
[0055] Signal envelope like Figure 10 shown.
[0056] In the examples of this application, see Figure 11 The phase demodulation unit can obtain the reference signal by demodulating the phase estimation method based on the conjugate operation. and signal envelope The phase difference between ,in, is the phase difference caused by the spatial path difference of antenna B relative to antenna A; The phase difference is caused by the difference in the uplink path of antenna B relative to antenna A.
[0057] Since the position information of the far-field calibration antenna is known, the spatial path difference can be calculated based on the position information of antennas A and B, the position information of the far-field calibration antenna, and the frequency of the calibration signal. , and finally the channel phase difference obtained from the phase demodulation unit is Deduct The phase difference caused by the difference in the uplink channel of antenna B relative to antenna A can be obtained ,Right now:
[0058] In the examples of this application, see Figure 12 The process of calibrating the relative signal delay of the antenna uplink channel is as follows: Figure 12 As shown in the figure: After the relative delay of the uplink channel signal of antenna B is calibrated with antenna A as the reference, the uplink frequency point is first Calibrate the relative phase difference of the uplink channel of antenna B relative to antenna A , then the uplink frequency Calibrate the relative phase difference of the uplink channel of antenna B relative to antenna A Finally, the relative delay difference of the uplink signal of antenna B relative to antenna A is obtained according to the phase slope estimation method. for:
[0059] The present application also provides an embodiment of an uplink channel signal delay calibration system using a far-field calibration system, which is applicable to the uplink channel signal delay calibration method using a far-field calibration system described in the above embodiment, and includes an uplink channel calibration unit, an antenna array and a far-field calibration system; the uplink channel calibration unit is composed of an uplink channel calibration signal generator, a dual-channel phase calibration unit and a channel selection unit; the channel selection unit is connected to the uplink channel calibration signal generator through the dual-channel phase calibration unit; the uplink channel signal generator is composed of a digitally controlled oscillator and an uplink channel calibration signal modulation unit; the digitally controlled oscillator is connected to the uplink channel calibration signal modulation unit.
[0060] Optionally, the dual-channel phase correction unit includes a signal amplitude demodulation unit, a phase generating unit, and a phase demodulation unit; the signal amplitude demodulation unit is respectively connected to the phase generating unit and the phase demodulation unit; the signal amplitude demodulation unit is connected to the phase generating unit; the phase generating unit includes a phase generator, a timer, and a reference signal generator; the phase generation is respectively connected to the timer and the reference signal generator; the signal amplitude demodulation unit includes a phase-locked loop and an amplitude estimation unit; the phase-locked loop is connected to the amplitude estimation unit.
[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present application should be included in the scope of protection of the claims of the present application.
Claims
1. A method for calibrating uplink channel signal delay using a far-field calibration system, characterized in that: include: The uplink channel calibration unit generates an uplink channel calibration reference signal and an uplink channel calibration modulated signal and sends them to the reference antenna and the antenna to be calibrated respectively; The reference antenna is any antenna in the antenna array, and the antenna to be calibrated is any antenna in the antenna array except the reference antenna. The uplink channel calibration reference signal is the uplink signal, and the uplink channel calibration modulation signal is the uplink signal after phase modulation; The reference antenna and the antenna to be calibrated send the signals they receive to the far-field calibration system; The far-field calibration system converts the received signal into a downlink signal and sends it to the uplink channel calibration unit through the reference antenna and the antenna to be calibrated; The uplink channel calibration modulation signal demodulates the received signal sent by the far-field calibration system into a signal envelope, and obtains the relative phase difference of the uplink channel signal based on the signal envelope; According to the relative phase difference of the uplink channel signal, the phase difference caused by the difference in the uplink channel of the antenna to be calibrated relative to the reference antenna is obtained; Different uplink frequency points are selected to calibrate the relative phase difference of the uplink channel of the antenna to be calibrated relative to the reference antenna, and the relative signal delay difference of the uplink channel of the antenna to be calibrated relative to the reference antenna is obtained.
2. The uplink channel signal delay calibration method using a far-field calibration system according to claim 1, characterized in that: The digitally controlled oscillator in the uplink channel calibration signal generator in the uplink channel calibration unit generates an uplink signal according to the uplink frequency set by the system, and divides the uplink signal into two paths, one of which is directly sent to the reference antenna as the uplink channel calibration reference signal, and the other path passes through the uplink channel calibration signal modulation unit in the uplink channel calibration signal generator; The signal modulation unit of the uplink channel calibration performs phase modulation on the uplink signal according to the phase value to obtain the uplink channel calibration modulated signal and sends it to the antenna to be calibrated; The uplink channel calibration reference signal of the reference antenna is: The uplink channel calibration modulation signal after phase modulation of the antenna to be calibrated is: in, It is the phase difference between the reference antenna and the antenna to be calibrated due to the spatial path difference; It is the phase difference between the reference antenna and the antenna to be calibrated due to the difference in the antenna's own uplink channel; The amplitude of the uplink signal received by the reference antenna at the antenna aperture for calibration; and is a slowly changing phase value, is the angular frequency, For time, is the frequency.
3. The uplink channel signal delay calibration method using a far-field calibration system according to claim 1, characterized in that: The far-field calibration system includes a calibration antenna; taking the signal transmitted by the reference antenna received by the calibration antenna aperture as a reference, and the signal of the antenna to be calibrated The sum of , obtain the composite signal of the signals transmitted by the reference antenna and the antenna to be calibrated on the calibration antenna aperture and regard it as an amplitude modulated signal ; in, is the angular frequency, For time, is the frequency, It is the phase difference between the reference antenna and the antenna to be calibrated due to the spatial path difference; It is the phase difference between the reference antenna and the antenna to be calibrated due to the difference in the antenna's own uplink channel; The uplink signal amplitude of the reference antenna received by the calibration antenna aperture; is a slowly changing phase value, is the angular frequency; The calibration antenna in the far-field calibration system converts the synthesized signal into a downlink signal and then sends it to the reference antenna and the antenna to be calibrated; after receiving the synthesized downlink signal, the reference antenna and the antenna to be calibrated send it to the channel selection unit in the uplink channel calibration unit; The channel selection unit selects one channel from the downlink signals received from the reference antenna and the antenna to be calibrated, that is, the composite signal, and sends it to the dual-channel phase calibration unit in the uplink channel calibration unit for phase calibration processing; the dual-channel phase calibration unit calibrates the channel phase and sends the phase value to the uplink channel signal generator in the uplink channel calibration unit.
4. The uplink channel signal delay calibration method using a far-field calibration system according to claim 3, characterized in that: The signal amplitude demodulation unit in the dual-channel phase calibration unit receives the composite signal transmitted by the calibration antenna and transmitted by the reference antenna or the antenna to be calibrated and demodulates the signal envelope therefrom; The phase generator in the dual-channel phase correction unit generates a slowly varying phase value , and divide it into two paths, one path is sent to the uplink channel calibration signal generator to modulate the uplink signal of the antenna to be calibrated, and the other path is sent to the reference signal generator to generate a reference signal for phase demodulation : The dual-channel phase correction unit first locks the signal after the automatic gain control AGC through the phase-locked loop PLL, and uses the reference signal output by the phase-locked loop in the amplitude estimation unit to obtain the slowly changing envelope of the input signal using a coherent method; the amplitude estimation unit is controlled by the timing pulse sent by the phase generation unit. After receiving each timing pulse, it waits until a fixed signal transmission delay value is reached, and estimates the signal amplitude before the next timing pulse arrives, and finally obtains the signal envelope. for: 。 5. The uplink channel signal delay calibration method using a far-field calibration system according to claim 4, characterized in that: The timer in the phase generating unit generates a timing pulse according to a timing time interval preset by the system and sends it to the phase generator in the phase generating unit; The phase generator generates a phase value through the received timing pulse and divides it into two paths, one path is directly sent to the uplink channel calibration signal generator, and the other path is sent to the reference signal generator to generate a reference signal for phase demodulation.
6. The method for calibrating uplink channel signal delay using a far-field calibration system according to claim 5, characterized in that: The timer also sends a timing pulse to the signal amplitude demodulation unit so that it controls the envelope of the synthesized signal; the period of the timing pulse preset by the system is greater than the signal transmission and envelope demodulation time.
7. The method for calibrating uplink channel signal delay using a far-field calibration system according to claim 4, characterized in that: In the signal amplitude demodulation unit, the synthesized signal is locked by a phase-locked loop after automatic gain control, and the amplitude estimation unit uses the reference signal output by the phase-locked loop to obtain the signal envelope of the synthesized signal.
8. The uplink channel signal delay calibration method using a far-field calibration system according to claim 7, characterized in that: The amplitude estimation unit is controlled by the timing pulse sent by the phase generation unit. After receiving each timing pulse, it waits for a fixed signal transmission delay value and estimates the signal amplitude before the next timing pulse arrives to obtain the signal envelope.
9. The method for calibrating uplink channel signal delay using a far-field calibration system according to claim 3, characterized in that: The phase demodulation unit in the dual-channel phase correction unit obtains the reference signal by demodulating the phase estimation method based on the conjugate operation. The real part of and signal envelope The phase difference between ,in, is the phase difference caused by the spatial path difference between the antenna to be calibrated and the reference antenna; The phase difference is caused by the difference in the uplink channel of the antenna to be calibrated relative to the reference antenna; According to the position information of the reference antenna and the antenna to be calibrated, the position information of the far-field calibration antenna and the frequency of the calibration signal, the phase difference caused by the spatial path difference is obtained. ,from Subtract , we can get the phase difference caused by the difference in the uplink channel of the antenna to be calibrated relative to the reference antenna .
10. The uplink channel signal delay calibration method using a far-field calibration system according to claim 1, characterized in that: Calibrate the uplink channel relative phase difference of the antenna to be calibrated relative to the reference antenna at the uplink frequency point , calibrate the uplink channel relative phase difference of the antenna to be calibrated relative to the reference antenna using the uplink frequency point According to the phase slope estimation method, the relative delay difference of the uplink signal of the antenna to be calibrated relative to the reference antenna is obtained. .
11. An uplink channel signal delay calibration system using a far-field calibration system, applicable to the uplink channel signal delay calibration method using a far-field calibration system according to any one of claims 1 to 10, characterized in that: It includes an uplink channel calibration unit, an antenna array and a far-field calibration system; the uplink channel calibration unit consists of an uplink channel calibration signal generator, a dual-channel phase calibration unit and a channel selection unit; the channel selection unit is connected to the uplink channel calibration signal generator through the dual-channel phase calibration unit; the uplink channel signal generator consists of a digitally controlled oscillator and a signal modulation unit for uplink channel calibration; the digitally controlled oscillator is connected to the signal modulation unit for uplink channel calibration.
12. The uplink channel signal delay calibration system using a far-field calibration system according to claim 11, characterized in that: The dual-channel phase correction unit includes a signal amplitude demodulation unit, a phase generation unit, and a phase demodulation unit; the signal amplitude demodulation unit is respectively connected to the phase generation unit and the phase demodulation unit; the signal amplitude demodulation unit is connected to the phase generation unit; the phase generation unit includes a phase generator, a timer and a reference signal generator; the phase generation is respectively connected to the timer and the reference signal generator; the signal amplitude demodulation unit includes a phase-locked loop and an amplitude estimation unit; the phase-locked loop is connected to the amplitude estimation unit.