Satellite-borne receiving multi-channel amplitude-phase error calibration method

Abstract

A kind of satellite-borne receiving multi-channel amplitude-phase error calibration method, overall combine calibration signal and interference detection result, according to interference situation, the frequency of calibration signal, spreading code length and accumulation time can be changed, to achieve the purpose of accurate calibration system;At the same time, due to the large temperature variation of satellite-borne multi-feed antenna, temperature sensor is used to collect the temperature value of down-conversion receiving component, and calibration compensation is carried out at different temperatures, to improve the amplitude-phase error calibration accuracy of the system;Solve the amplitude-phase error calibration problem under unknown interference conditions, and use temperature value to improve the calibration compensation accuracy at different temperatures.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of array signal processing, and particularly relates to a kind of star-borne receiving multi-channel amplitude and phase error calibration methods. BACKGROUND

[0002] For the traditional star-borne multi-channel amplitude and phase calibration technology, two methods of external calibration and internal calibration are adopted, the external calibration technology needs to install an additional transmitting antenna outside the receiving antenna for calibration signal transmission, and the internal calibration technology designs a switch at the input end, switches the switch for calibration processing during calibration, and the star-borne product has a wide working temperature range, so that the channel amplitude and phase error will change greatly when the temperature changes, affecting the calibration accuracy of the system. SUMMARY

[0003] In view of the above problems, the purpose of the application is to provide a kind of star-borne receiving multi-channel amplitude and phase error calibration method, solve the problem of multi-channel amplitude and phase error calibration under unknown interference and wide working temperature range.

[0004] To achieve the above purpose, the technical scheme adopted by the application includes:

[0005] A kind of star-borne receiving multi-channel amplitude and phase error calibration method, comprising the following steps:

[0006] S1, a plurality of groups of radio frequency signals pass through a plurality of groups of coupled couplers and down-conversion receiving components to obtain a plurality of groups of first intermediate frequency signals, a plurality of groups of first intermediate frequency signals are collected by a plurality of ADCs to obtain a plurality of first digital signals, interference detection and SNR estimation are performed on all first digital signals, and a calibration signal frequency f0 and a calibration signal code length N are obtained;

[0007] The temperature value of the down-conversion receiving component is obtained, and the temperature value is collected by the ADC to obtain a temperature signal;

[0008] S2, according to the calibration signal frequency f0 and the calibration signal code length N obtained in S1, a spread spectrum modulation signal S(t) is generated, the spread spectrum modulation signal is converted into an analog intermediate frequency signal by a DAC, the analog intermediate frequency signal is converted into a radio frequency signal by an up-conversion transmitting component, and the radio frequency signal is converted into a plurality of calibration radio frequency signals by a power dividing network;

[0009] S3, the output of S2 is a plurality of calibration radio frequency signals, which are coupled by a plurality of couplers to obtain a plurality of groups of calibration signals and uplink signals, the plurality of groups of calibration signals and uplink signals pass through a plurality of down-conversion components respectively to obtain a plurality of groups of second intermediate frequency signals, and the plurality of groups of second intermediate frequency signals are collected by a plurality of ADCs to obtain a plurality of second digital signals;

[0010] S4, the multiple second digital signals obtained from S3 are respectively and sequentially subjected to despread demodulation, accumulated integration and signal-to-noise ratio estimation, when the signal-to-noise ratio is lower than the required signal-to-noise ratio, the accumulated integration time is doubled; after the required signal-to-noise ratio is reached, the amplitude and phase error of the multiple second digital signals and the temperature signal obtained from S1 is calculated to obtain the calibration weight at the storage temperature and the calibration weight at the storage temperature is stored when the direction finding channel is working to compensate the error.

[0011] Preferably, the spread spectrum modulated signal S(t) is calculated by formula (1) in S2:

[0012] S(t) = Ac(t)cos2πf0t (1)

[0013] wherein A represents the amplitude of the calibration signal, c represents the code sequence of the calibration signal, c is obtained according to the code length N of the calibration signal, and t represents time.

[0014] Preferably, the calibration weight at the storage temperature is stored in S4 The calculation process is specifically as follows:

[0015] S41, the amplitude and phase error between the direction finding channels is measured for the multiple second digital signals, and the initial calibration weight of the direction finding channel is formed after the measurement

[0016] S42, the amplitude and phase error between the calibration channels is obtained by processing the multiple second digital signals, and the calibration weight of the calibration channel is formed

[0017] S43, the amplitude and phase error of the calibration channel is measured when the amplitude and phase error is calculated and the calibration weight at the storage temperature is obtained by formula (2)

[0018]

[0019] Preferably, the accumulated integration time in S4 is 1ms, and the maximum integration time after the accumulated integration time is doubled is 100ms.

[0020] Preferably, the step of the temperature value is 5℃, if the temperature value and the calibration weight at the storage temperature are searched to 5℃ or above, the S1-S4 needs to be executed in a loop to recalibrate to obtain the new calibration weight at the storage temperature.

[0021] Compared with the prior art, the application has the following advantages:

[0022] The satellite-borne receiving multi-channel amplitude and phase error calibration method of the application combines the calibration signal and the interference detection result as a whole, and can change the frequency, the spread spectrum code length and the accumulation time of the calibration signal according to the interference condition, so as to achieve the purpose of accurate calibration of the system. Meanwhile, due to the large change of the working temperature of the satellite-borne multi-feed antenna, the temperature sensor is used to collect the temperature value of the down-conversion receiving component, and the calibration compensation is performed at different temperatures, so as to improve the amplitude and phase error calibration precision of the system. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings are included to provide a further understanding of the application, and constitute a part of the specification, and together with the specific embodiments below, serve to explain the application, but do not constitute a limitation on the application. In the drawings:

[0024] Figure 1 The flow chart of the satellite-borne receiving multi-channel amplitude and phase error calibration method of the application. DETAILED DESCRIPTION

[0025] The application is not limited to the following specific embodiments, and any equivalent transformation made on the basis of the technical solutions of the application falls within the protection scope of the application. All the components and devices in the application, if not specifically stated, are all the components and devices known in the prior art.

[0026] EMBODIMENT

[0027] A satellite-borne receiving multi-channel amplitude and phase error calibration method, comprising the following steps:

[0028] S1, a plurality of groups of radio frequency signals pass through a plurality of groups of coupled couplers and down-conversion receiving components to obtain a plurality of groups of first intermediate frequency signals, the plurality of groups of first intermediate frequency signals pass through a plurality of ADCs to obtain a plurality of first digital signals, interference detection and SNR estimation are performed on all the first digital signals to obtain a calibration signal frequency f0 and a calibration signal code length N, and a temperature value of the down-conversion receiving component is obtained, wherein the temperature value is obtained by an ADC to obtain a temperature signal;

[0029] S2, a spread spectrum modulation signal S(t) is generated according to the calibration signal frequency f0 and the calibration signal code length N obtained in S1, the spread spectrum modulation signal is converted into an analog intermediate frequency signal by a DAC, the analog intermediate frequency signal is converted into a radio frequency signal by an up-conversion transmitting component, and the radio frequency signal is converted into a plurality of calibration radio frequency signals by a power dividing network;

[0030] S3, the output plurality of calibration radio frequency signals obtained in S2 are coupled by a plurality of couplers to obtain a plurality of groups of calibration signals and uplink signals, the plurality of groups of calibration signals and uplink signals pass through a plurality of down-conversion components to obtain a plurality of groups of second intermediate frequency signals, and the plurality of groups of second intermediate frequency signals pass through a plurality of ADCs to obtain a plurality of second digital signals;

[0031] S4, the multiple second digital signals obtained in S3 are respectively and sequentially subjected to despread demodulation, accumulated integration and signal-to-noise ratio estimation, when the signal-to-noise ratio estimation is lower than the required signal-to-noise ratio, the accumulated integration time is doubled; after reaching the required signal-to-noise ratio, the multiple second digital signals and the temperature signal obtained in S1 are subjected to amplitude and phase error calculation to obtain the calibration weight at the storage temperature and the calibration weight at the storage temperature is used to compensate the error when the direction finding channel is working .

[0032] The calibration signal and the interference detection result are combined as a whole, the frequency, the spread spectrum code length and the accumulated time of the calibration signal can be changed according to the interference condition, so as to achieve the purpose of accurate calibration system; meanwhile, since the working temperature of the spaceborne multi-feed antenna changes greatly, the temperature sensor is used to collect the temperature value of the down-conversion receiving assembly, the calibration compensation is performed at different temperatures, and the amplitude and phase error calibration precision of the system is improved.

[0033] In the embodiment, if the working bandwidth of the receiving channel is B1 and the frequency of the radio frequency signal is f1, the in-band interference frequency and power are detected, if there is no interference in the band, the calibration signal frequency f0 is selected as the default frequency f1, and the calibration signal code length N is selected as the default code length 2 10 ; if there is interference and the interference frequency is f2, the frequency f3 farthest from f2 in the band is selected as the calibration signal frequency f0; if the interference power is 15dB or less than the calibration signal power, the calibration signal code length is selected as the default code length 2 10 ; if the interference power is 15dB or more than the calibration signal power, the calibration signal code length is increased by one time for each 3dB increase of the interference power, and the longest code length is 2 14 .

[0034] In the embodiment S2, the spread spectrum modulated signal S(t) is calculated by formula (1):

[0035] s(t) = Ac(t)cos2πf0t (1)

[0036] In the embodiment S4, the calibration weight at the storage temperature is stored The calculation process is specifically as follows:

[0037] S41, the amplitude and phase error between the multiple second digital signals is measured, and the initial calibration weight of the direction finding channel is formed after the measurement Wherein, the first path is used as the reference path, the amplitude and phase error between the signals of the first path and the remaining paths is calculated to form the calibration weight, and the amplitude and phase error between the paths is compensated after the calibration weight is multiplied by the signal. The initial calibration weight is obtained by using an external input signal as a calibration signal, the signals with consistent amplitude and phase are input into the multiple receiving channels, and the calibration weight is calculated after ADC sampling.

[0038] S42, the amplitude and phase errors between the calibration channels of the multi-path second digital signal processing are obtained to form the calibration weight value of the calibration channel

[0039] The initial calibration weight value obtained in S41 is stored in the storage space and the calibration weight value of the calibration channel obtained in S42 is stored in the storage space to obtain the basic weight value;

[0040] S43, the amplitude and phase errors of the calibration channel are measured when the amplitude and phase errors are calculated and the calibration weight value at the storage temperature is obtained through formula (2) and is stored in the storage space;

[0041]

[0042] After the intermediate frequency sampling, the first signal is first down-converted according to the radio frequency signal sent in S1 to obtain a first intermediate frequency signal, and the code phase of all the first intermediate frequency signals is searched according to the code phase step , and after the search, the code phase is accurately searched according to in the code phase of to obtain the final code phase. Then, the multi-channel starts to perform the despreading correlation integration according to the final code phase, and the time of the accumulated integration is 1ms, and the maximum integration time after the time of the accumulated integration is doubled is 100ms.

[0043] According to the obtained integration results of each channel, the first signal is taken as the reference signal I1+j*Q1, the second signal to the last multi-channel signal Q is taken as I n -j*Q n , and then the correlation operation is performed between the first signal and each of the subsequent signals to obtain the amplitude and phase difference between the first signal and each of the subsequent signals, and the calibration weight value at the storage temperature is finally obtained according to the amplitude and phase difference

[0044] The value of the temperature sensor in the embodiment is sampled by the ADC to obtain the current temperature value, in order to obtain the accurate amplitude and phase errors when the channel temperature changes, the temperature value step is 5℃, if the current temperature value and the temperature of the stored calibration value reach more than 5℃, then the new calibration weight value at the new temperature value is obtained by re-executing S1-S4 calibration, and the storage space is re-opened for storage. In this way, each set of calibration weight values is related to a set of temperature values. To achieve the purpose of accurate calibration under temperature change.

[0045] The above embodiments are only specific application examples of the present application, and in actual operation, corresponding adjustments can be made according to the specific conditions of the field geological conditions, detection requirements and technical equipment to achieve the best detection effect.

[0046] Through the above steps, a new satellite-received multi-channel amplitude and phase error calibration method is realized, which effectively solves the problems existing in the prior art, and plays a positive promoting role for coal mine safety production and industry development.

[0047] The preferred embodiments of the present disclosure are described in detail above in combination with the drawings, but the present disclosure is not limited to the specific details in the above embodiments, and various simple modifications can be made to the technical solutions of the present disclosure within the technical concept of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0048] In addition, it should be noted that various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, various possible combination manners are not described again in the present disclosure.

[0049] In addition, various different embodiments disclosed in the present solution can also be combined in any manner, as long as it does not deviate from the idea of the present solution, and it should also be considered as the content invented by the present solution.

Claims

1. A method for calibrating the amplitude and phase error of a multi-channel satellite receiver, characterized in that, Includes the following steps: S1, multiple radio frequency signals are respectively passed through multiple series couplers and downconversion receiving components to obtain multiple first intermediate frequency signals. Multiple first intermediate frequency signals are acquired by multiple ADCs to obtain multiple first digital signals. Interference detection and SNR estimation are performed on all first digital signals to obtain the calibration signal frequency f0 and calibration signal code length N. The temperature value of the downconverter receiving component is obtained, and the temperature value is acquired as a temperature signal by an ADC. S2, based on the calibration signal frequency f0 and calibration signal code length N obtained in S1, a spread spectrum modulation signal S(t) is generated. The spread spectrum modulation signal is converted into an analog intermediate frequency signal by a DAC. The analog intermediate frequency signal is converted into a radio frequency signal by an up-conversion transmitting component. The radio frequency signal is converted into multiple calibration radio frequency signals by a power divider network. The multi-channel calibration RF signals obtained from S3 and S2 are cyclically coupled through multiple couplers to obtain multiple sets of calibration signals and uplink signals. The multiple sets of calibration signals and uplink signals are respectively processed through multiple sets of downconversion components to obtain multiple sets of second intermediate frequency signals. The multiple sets of second intermediate frequency signals are acquired by multiple ADCs to obtain multiple second digital signals. S4: Despreading, demodulation, integration, and signal-to-noise ratio (SNR) estimation are performed sequentially on the multiple second digital signals obtained in S3. If the SNR estimation is lower than the required SNR, the integration time is doubled. After the required SNR is achieved, amplitude and phase errors are calculated on the multiple second digital signals and the temperature signal obtained in S1 to obtain the calibration weight A0e at the storage temperature. jφ0 And when the direction finding channel is working, it uses the calibration weight A0e at the storage temperature. jφ0 Perform error compensation.

2. The method for calibrating the amplitude and phase error of a multi-channel satellite receiver as described in claim 1, characterized in that, The spread spectrum modulation signal S(t) is obtained by equation (1) in S2: S(t)=Ac(t)cos2πf0t (1) Where A represents the amplitude of the calibration signal, c represents the code sequence of the calibration signal, the code sequence c of the calibration signal is derived from the code length N of the calibration signal, and t represents time.

3. The method for calibrating multi-channel amplitude and phase errors in spaceborne receivers as described in claim 1, characterized in that, The calibration weight at the S4 storage temperature The calculation process is as follows: S41, measure the amplitude and phase error between the direction-finding channels of the multiple second digital signals, and form the initial calibration weights of the direction-finding channels after the measurement. S42 processes the multiple second digital signals to obtain the amplitude and phase errors between each channel of the calibration channel, forming the calibration weights for the calibration channels. S43, Measure the amplitude and phase error of the calibration channel when calculating amplitude and phase error. The calibration weights at the storage temperature are obtained using equation (2).

4. The satellite-borne receiver multi-channel amplitude and phase error calibration method as described in claim 1, characterized in that, The integration time in S4 is 1ms, and the maximum integration time after doubling the integration time is 100ms.

5. The satellite-borne receiver multi-channel amplitude and phase error calibration method as described in any one of claims 1-4, characterized in that, The temperature value increment is 5°C, based on the calibration weights at the current temperature and the storage temperature. If the temperature difference reaches 5°C or more, it is necessary to cycle through S1-S4 to recalibrate and obtain the calibration weight at the new storage temperature.

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