Interference cancellation apparatus and method for ka and ku band multi-mode satcom ground stations

Abstract

The application belongs to the technical field of satellite communication interference protection, and specifically discloses an interference cancellation device and method for a Ka and Ku frequency band multi-mode satellite communication ground station, wherein the device comprises: a sampling antenna module, which is used for collecting Ku / Ka frequency band sampling signals from space; a radio frequency receiving module, which is used for selecting the polarization direction of the sampling signals based on the polarization mode of the satellite communication antenna and converting the sampling signals into sampling intermediate frequency signals; a sampling signal selection module, which is used for dividing the sampling intermediate frequency signals into sub-signals and selecting different frequency band sub-signals based on the working frequency band of the satellite communication terminal; and a signal processing module, which is used for obtaining interference cancellation output signals free of interference by performing interference cancellation on the fth satellite communication signal through an adaptive filtering algorithm based on N-path target frequency band sampling intermediate frequency sub-signals. The application is suitable for the satellite communication ground station for realizing Ka / Ku dual-band multi-mode communication through a radio frequency switch matrix shared satellite communication antenna, and realizes mutual decoupling of anti-interference processing between different satellite communication terminals.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of satellite communication interference protection, and more particularly to an interference cancellation device and method for a Ka and Ku frequency band multi-mode satellite communication ground station. BACKGROUND

[0002] Satellite communication is a wireless communication technology that relies on satellite relay to achieve long-distance information transmission. In particular, in long-distance over-the-horizon high-speed data transmission and other application scenarios, satellite communication has an irreplaceable position. Satellite communication is an important electromagnetic interference, and improving the electromagnetic interference protection capability of satellite communication has important practical value.

[0003] Using array antenna beamforming can improve the interference suppression capability of satellite communication ground stations. Simply put, by receiving signals through multiple antenna elements, the received signals are then vector synthesized to make the synthesized beam null direction align with the interference source, thereby achieving interference suppression. In the field of communication interference cancellation technology, adaptive filtering algorithms are commonly used to achieve interference cancellation functions. The Least Mean Square (LMS) algorithm and its variants have the characteristics of simple structure and low complexity, and are widely used.

[0004] The satellite communication interference suppression technology based on array antenna beamforming faces the following difficulties in the development process: First, a single satellite communication ground station can work in multiple communication frequency bands such as Ku, Ka, etc., but traditional beamforming interference suppression methods only support one communication frequency band, such as Ku or Ka band, and cannot support anti-jamming for multiple frequency bands at the same time. Independent hardware circuits are used to implement anti-jamming processing for Ku and Ka frequency bands respectively, which has high hardware complexity and cost. Second, the same satellite communication ground station can use multiple communication modes at the same time, such as Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA) communication modes, etc., and in practice multiple communication modes may work at multiple frequency points. However, traditional satellite communication anti-jamming technology can only process a single frequency point or two frequency points or a certain communication mode, and does not support multi-frequency point and multi-communication mode satellite terminals. Third, the satellite communication ground station generally uses a parabolic antenna to receive downlink signals of multiple operating frequency points and multiple different communication modes, and then distributes the received signals of different communication modes to multiple different satellite terminals through a radio frequency switch matrix, making it difficult to independently process each terminal without affecting each other.

[0005] CN113922889A discloses a multi-frequency interference cancellation device for a Ku and Ka dual-band satellite communication ground station. The device realizes spatial sampling of interference signals in multiple frequency bands by combining sampling antenna units operating in different frequency bands. At the same time, multiple signal processing modules are used to process communication signals distributed in any frequency band and at any frequency point, thereby realizing Ku / Ka dual-band, multi-frequency point beamforming anti-interference, effectively overcoming the problem that traditional solutions can only process communication signals distributed in a single or two frequency points in the same frequency band.

[0006] However, the multi-frequency interference cancellation device of the Ku and Ka dual-band satellite communication ground station is connected between the satellite communication antenna and the satellite communication ground station terminal, which is not suitable for satellite communication ground stations with radio frequency switch matrices, and this access method cannot completely decouple the mutual influence between the satellite communication ground station terminal and other satellite communication ground station terminals. Summary of the Invention

[0007] In response to the defects of related technologies, the embodiments of the present application provide an interference cancellation device and method for a Ka and Ku band multi-mode satellite communication ground station, aiming to solve the problems of the inapplicability of satellite communication ground stations with radio frequency switch matrices and the mutual influence between multiple satellite communication ground station terminals.

[0008] In a first aspect, an embodiment of the present application provides an interference cancellation device for a Ka and Ku band multi-mode satellite communication ground station, comprising:

[0009] The interference cancellation device is connected between the output port of the radio frequency switch matrix of the satellite communication ground station and the input ports of different satellite communication terminals;

[0010] The interference cancellation device includes:

[0011] A sampling antenna module, comprising N sampling antenna units, wherein the sampling antenna units are used to collect Ku-band sampling signals and Ka-band sampling signals from space;

[0012] a radio frequency receiving module, comprising N radio frequency receiving component groups, the radio frequency receiving component groups comprising a Ku-band radio frequency receiving component and a Ka-band radio frequency receiving component, configured to select a polarization direction of a Ku-band sampled signal based on a polarization mode of a satellite communication antenna in the Ku band, select a polarization direction of a Ka-band sampled signal based on a polarization mode of a satellite communication antenna in the Ka band, and convert the collected Ku-band sampled signal into a Ku-band sampled intermediate frequency signal, and convert the collected Ka-band sampled signal into a Ka-band sampled intermediate frequency signal;

[0013] a sampling signal selection module, comprising N 2×F radio frequency switch matrices, the 2×F radio frequency switch matrices being used to divide a Ku-band sampled intermediate frequency signal into F Ku-band sampled intermediate frequency sub-signals, divide a Ka-band sampled intermediate frequency signal into F Ka-band sampled intermediate frequency sub-signals, and select the f-th Ku-band sampled intermediate frequency sub-signal or the f-th Ka-band sampled intermediate frequency sub-signal based on an operating frequency band of the f-th satellite communication terminal;

[0014] The signal processing module includes F signal processing units, where the fth signal processing unit is used to sample intermediate frequency sub-signals of N target frequency bands input by N 2×F radio frequency switch matrices, perform interference cancellation on the fth satellite communication signal using an adaptive filtering algorithm, and obtain an interference-free interference cancellation output signal;

[0015] The frequency band of the target frequency band sampling intermediate frequency sub-signal is the same as the working frequency band of the f-th satellite communication terminal, the f-th satellite communication signal is the satellite communication signal of the f-th satellite communication terminal, the value of f ranges from 1 to F, and N, f and F are all positive integers.

[0016] In some embodiments, the signal processing unit includes a digital signal processing unit, and the digital signal processing unit includes a delayer, a master beamformer, a weight updater, a weight filter, and a slave beamformer;

[0017] The delayer is used to delay the input N-channel target frequency band sampled digital sub-signals and output N-channel space-time auxiliary antenna reception signals. The target frequency band sampled digital sub-signals are obtained by down-converting and analog-to-digital converting the target frequency band sampled intermediate frequency sub-signals.

[0018] The main beamformer is used to determine the initial weights of the N-way space-time auxiliary antenna receiving signals, perform weighted processing on the N-way space-time auxiliary antenna receiving signals based on the initial weights after smoothing filtering, and synthesize them with the f-th satellite communication signal to output the initial interference cancellation signal;

[0019] The weight updater is used to output updated weights based on the N-way space-time auxiliary antenna received signals and the initial interference cancellation signal using an adaptive filtering algorithm;

[0020] The weight filter is used to smooth the updated weights and output the final weights;

[0021] The slave beamformer is used to perform weighted processing on the N-way space-time auxiliary antenna receiving signals based on the final weight value and synthesize them with the f-th satellite communication signal to output an interference cancellation signal in the digital domain.

[0022] In some embodiments, the signal processing unit includes N+1 downconverters, N+1 analog-to-digital converters, a digital signal processing unit, a digital-to-analog converter, and an upconverter;

[0023] The downconverter is used to downconvert the sampled intermediate frequency sub-signal of the target frequency band to baseband or low intermediate frequency, and output the sampled baseband sub-signal or the sampled low intermediate frequency sub-signal, or to downconvert the satellite communication signal to baseband or low intermediate frequency, and output the satellite communication baseband signal or the satellite communication low intermediate frequency signal;

[0024] The analog-to-digital converter is used to convert the sampled baseband sub-signal or the sampled low intermediate frequency sub-signal into a sampled digital sub-signal of a target frequency band, or to convert the satellite communication baseband signal or the satellite communication low intermediate frequency signal into a satellite communication digital signal;

[0025] The digital signal processing unit is used to sample digital sub-signals based on N target frequency bands, perform interference cancellation on the satellite communication digital signal through an adaptive filtering algorithm, and obtain an interference cancellation signal in the digital domain;

[0026] The digital-to-analog converter is used to convert the interference cancellation signal in the digital domain into an analog baseband signal or an analog low intermediate frequency signal;

[0027] The up-converter is used to up-convert the analog baseband signal or the analog low intermediate frequency signal to an intermediate frequency output as the interference cancellation output signal corresponding to the f-th satellite communication terminal.

[0028] In some embodiments, in the f-th signal processing unit:

[0029] The input ports of N down-converters among the N+1 down-converters are respectively connected to the output ports of the f-th input RF switch in the N 2×F RF switch matrices, and the output ports are respectively connected to N analog-to-digital converters, for down-converting the input N frequency band sampled intermediate frequency sub-signals to baseband or low intermediate frequency, and outputting N sampled baseband sub-signals or sampled low intermediate frequency sub-signals; the input ports of the down-converters other than the N down-converters receive the f-th satellite communication signal corresponding to the f-th satellite communication terminal, and the output ports are connected to the input ports of the analog-to-digital converters other than the N analog-to-digital converters, for down-converting the f-th satellite communication signal to baseband or low intermediate frequency, and outputting the satellite communication baseband signal or the satellite communication low intermediate frequency signal;

[0030] The output ports of the N+1 analog-to-digital converters are respectively connected to the N+1 input ports of the digital signal processing unit, the N analog-to-digital converters among the N+1 analog-to-digital converters are used to convert the N channels of sampled baseband sub-signals or sampled low-intermediate-frequency sub-signals into N channels of sampled digital sub-signals of the target frequency band, and the analog-to-digital converters other than the N analog-to-digital converters are used to convert the satellite communication baseband signal or the satellite communication low-intermediate-frequency signal into a satellite communication digital signal;

[0031] The output port of the digital signal processing unit is connected to the input port of the digital-to-analog converter, and is used to sample digital sub-signals based on N target frequency bands, perform interference cancellation on the satellite communication digital signal through an adaptive filtering algorithm, and obtain an interference cancellation signal in the digital domain;

[0032] The output port of the digital-to-analog converter is connected to the input port of the up-converter, and is used to perform digital-to-analog conversion on the interference cancellation signal in the digital domain and output an analog baseband signal or an analog low intermediate frequency signal;

[0033] The up-converter up-converts the analog baseband signal or the analog low intermediate frequency signal to an intermediate frequency and outputs it as the interference cancellation output signal corresponding to the f-th satellite communication terminal.

[0034] In some embodiments, a 2×F RF switch matrix includes: 2 low noise amplifiers, 2 power splitters, and F input RF switches;

[0035] The low noise amplifier is used to amplify the input sampled intermediate frequency signal;

[0036] The power divider is used to divide the amplified sampled intermediate frequency signal into F-channel sampled intermediate frequency sub-signals;

[0037] The input radio frequency switch is used to select sampled intermediate frequency sub-signals of different frequency bands input by two power dividers based on the working frequency band of the satellite communication terminal.

[0038] In some embodiments, the two low-noise amplifiers are a Ku-band low-noise amplifier and a Ka-band low-noise amplifier, and the two power splitters are a Ku-band power splitter and a Ka-band power splitter. In the nth 2×F RF switch matrix:

[0039] The input port of the Ku-band low-noise amplifier receives the Ku-band sampled intermediate frequency signal output by the nth RF receiving component group, and the output port is connected to the input port of the Ku-band power splitter to amplify the Ku-band sampled intermediate frequency signal; the F output ports of the Ku-band power splitter are respectively connected to the first input ports of the F input RF switches to split the Ku-band sampled intermediate frequency signal into F Ku-band sampled intermediate frequency sub-signals;

[0040] The input port of the Ka-band low-noise amplifier receives the Ka-band sampled intermediate frequency signal output by the nth RF receiving component group, and the output port is connected to the input port of the Ka-band power splitter to amplify the Ka-band sampled intermediate frequency signal; the F output ports of the Ka-band power splitter are respectively connected to the second input ports of the F input RF switches to split the Ka-band sampled intermediate frequency signal into F Ka-band sampled intermediate frequency sub-signals;

[0041] The f-th input RF switch selects the input Ku-band sampled intermediate frequency sub-signal and the input Ka-band sampled intermediate frequency sub-signal based on the operating frequency band of the f-th satellite communication terminal, and outputs the Ku-band sampled intermediate frequency sub-signal or the Ka-band sampled intermediate frequency sub-signal;

[0042] The value of n ranges from 1 to N.

[0043] In some embodiments, the sampling antenna unit includes two sampling antenna subunits, namely a Ka-band sampling antenna subunit and a Ku-band sampling antenna subunit; the Ka-band sampling antenna subunit includes two polarization output ports, which respectively output right-hand circularly polarized sampling signals and left-hand circularly polarized sampling signals; the Ku-band sampling antenna subunit includes two polarization output ports, which respectively output horizontal orthogonal polarization sampling signals and vertical orthogonal polarization sampling signals.

[0044] In some embodiments, each radio frequency receiving component includes two pre-selected band pass filters, two low-noise amplifiers, a radio frequency switch, a down converter, and a multiplexer;

[0045] The input ports of the two pre-selected band pass filters are respectively connected to the two polarization output ports of the sampling antenna subunit of the same frequency band, and the output ports are respectively connected to the input ports of the two low-noise amplifiers, for filtering out signals of non-working frequency bands received by the sampling antenna subunit;

[0046] The output ports of the two low-noise amplifiers are respectively connected to the two input ports of the radio frequency switch, for low-noise amplification of the input sampling signals;

[0047] The output port of the radio frequency switch is connected to the input port of the down converter, for selecting the polarization direction of the sampling signals based on the polarization mode of the satellite communication antenna in the same frequency band of the sampling signals;

[0048] The intermediate frequency output port of the down converter is connected to the intermediate frequency input port of the multiplexer, for down-converting the sampling signals to intermediate frequency;

[0049] The reference clock output port of the multiplexer is connected to the reference clock input port of the down converter, and the direct current output port is respectively connected to the power input port of the low-noise amplifier, the radio frequency switch, and the down converter.

[0050] In some embodiments, the device further includes a feeding clock module, the input port of the feeding clock module is connected to the synthesis port of the multiplexer in the radio frequency receiving component, and the output port is connected to the input port of the sampling signal selection module, for providing power supply and clock signals for the radio frequency receiving module.

[0051] In a second aspect, the embodiments of the present application further provide an interference cancellation method for a Ka and Ku frequency band multi-mode satellite communication ground station, including:

[0052] Collecting N groups of Ku-band sampling signals and Ka-band sampling signals from space;

[0053] Selecting a polarization direction of a Ku-band sampled signal based on a polarization mode of the satellite communication antenna in the Ku band, selecting a polarization direction of a Ka-band sampled signal based on a polarization mode of the satellite communication antenna in the Ka band, and converting the collected Ku-band sampled signal into a Ku-band sampled intermediate frequency signal, and converting the collected Ka-band sampled signal into a Ka-band sampled intermediate frequency signal;

[0054] dividing the Ku-band sampled intermediate frequency signal into F Ku-band sampled intermediate frequency sub-signals, dividing the Ka-band sampled intermediate frequency signal into F Ka-band sampled intermediate frequency sub-signals, and selecting the f-th Ku-band sampled intermediate frequency sub-signal or the f-th Ka-band sampled intermediate frequency sub-signal based on the operating frequency band of the f-th satellite communication terminal;

[0055] Based on N target frequency band sampled intermediate frequency sub-signals, an adaptive filtering algorithm is used to perform interference cancellation on the f-th satellite communication signal to obtain an interference-free interference cancellation output signal. The frequency band of the target frequency band sampled intermediate frequency sub-signals is the same as the operating frequency band of the f-th satellite communication terminal.

[0056] The frequency band of the target frequency band sampling intermediate frequency sub-signal is the same as the working frequency band of the f-th satellite communication terminal, the f-th satellite communication signal is the satellite communication signal of the f-th satellite communication terminal, the value of f ranges from 1 to F, and N, f and F are all positive integers.

[0057] In some embodiments, obtaining an interference cancellation output signal free of interference includes:

[0058] Delay processing is performed on N target frequency band sampled digital sub-signals, and N space-time auxiliary antenna reception signals are output, wherein the target frequency band sampled digital sub-signals are obtained by down-converting and analog-to-digital converting the target frequency band sampled intermediate frequency sub-signals;

[0059] Determine the initial weights of the N-way space-time auxiliary antenna receiving signals, perform weighted processing on the N-way space-time auxiliary antenna receiving signals based on the initial weights after smoothing filtering, synthesize them with the f-th satellite communication signal, and output an initial interference cancellation signal;

[0060] Based on the N-way space-time auxiliary antenna receiving signal and the initial interference cancellation signal, an adaptive filtering algorithm is used to output the updated weights;

[0061] Perform smoothing filtering on the updated weights and output the final weights;

[0062] Based on the final weights, the N-way space-time auxiliary antenna receiving signals are weighted and synthesized with the f-th satellite communication signal to output an interference cancellation signal in the digital domain.

[0063] In some embodiments, the smoothing filter specifically satisfies:

[0064] w s (n)=1 / K(wm (n)+w m (n-1)+,…,w m (n-K+1))

[0065] Among them, w s (n) is the final weight after smoothing filtering, K is the length of the sliding window, w m (n)+w m (n-1)+,…,w m (n-K+1) is the sum of the initial weights updated from the nth to n-K+1th iterations.

[0066] In some embodiments, the smoothing filter specifically satisfies:

[0067] w s (n) = b × w s (n)+(1-b)w m (n)

[0068] Among them, w s (n) is the final weight after smoothing filtering, b is the forgetting factor, w m (n) is the initial weight obtained by the nth iteration update.

[0069] In some embodiments, the forgetting factor b satisfies:

[0070] b=1-2 -M

[0071] Wherein, M is a positive integer.

[0072] The embodiments of the present application provide an interference cancellation device and method for a Ka and Ku band multi-mode satellite communication ground station. The interference cancellation device is connected between the output port of the RF switch matrix of the satellite communication ground station and the input ports of different satellite communication terminals. It is suitable for a satellite communication ground station that realizes Ka / Ku dual-band multi-mode communication by sharing a satellite communication antenna through the RF switch matrix; the polarization direction of the sampled received signals in the Ka and Ku bands is selected in the RF receiving module, and the frequency band of the sampled received signals is selected in the sampling signal selection module, so that independent signal processing units can be used to process satellite communication signals in different modes, thereby realizing the mutual decoupling of anti-interference processing between different satellite communication terminals. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the technical solutions in this application or related technologies, the following is a brief introduction to the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0074] Figure 1 It is an interference cancellation device for a Ka and Ku band multi-mode satellite communication ground station provided in an embodiment of the present application;

[0075] Figure 2 is a structural diagram of a sampling antenna unit provided in an embodiment of the present application;

[0076] Figure 3 This is a schematic diagram of the structure of the radio frequency receiving component group provided in an embodiment of the present application;

[0077] Figure 4 Schematic diagram of the structure of the power and clock feeding module provided in an embodiment of the present application;

[0078] Figure 5 Schematic diagram of the structure of the sampling signal selection module provided in an embodiment of the present application;

[0079] Figure 6 This is a schematic diagram of the structure of a 2×F radio frequency switch matrix provided in an embodiment of the present application;

[0080] Figure 7 is a structural diagram of a signal processing unit provided in an embodiment of the present application;

[0081] Figure 8 1 is a structural diagram of a digital signal processing unit provided in an embodiment of the present application;

[0082] Figure 9 1 is a flow chart of an interference cancellation method for a multi-mode satellite communication ground station in the Ka and Ku bands provided in an embodiment of the present application;

[0083] Figure 10 2 is a schematic diagram comparing the mean square error of the output signals of the LMS algorithm provided in the embodiment of the present application and the method of the present application;

[0084] Figure 11 This is a schematic diagram comparing the mean square error of the output signals of the LMS algorithm provided in the embodiment of the present application and the method of the present application. DETAILED DESCRIPTION

[0085] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0086] Figure 1 The interference cancellation device of the Ka and Ku band multi-mode satellite communication ground station provided in the embodiment of the present application is as follows: Figure 1 As shown, the device is connected between the output port of the satellite communication radio frequency switch matrix of the satellite communication ground station and the input port of different satellite communication terminals, and the device at least includes:

[0087] The sampling antenna module comprises N sampling antenna units, each of which is used to collect Ka-band sampling signals and Ku-band sampling signals from space.

[0088] The radio frequency receiving module comprises N radio frequency receiving component groups, each of which is used to select the polarization direction of the Ku-band sampling signals based on the polarization mode of the satellite communication antenna in the Ku band, select the polarization direction of the Ka-band sampling signals based on the polarization mode of the satellite communication antenna in the Ka band, and convert the collected Ku-band sampling signals into Ku-band sampling intermediate frequency signals and convert the collected Ka-band sampling signals into Ka-band sampling intermediate frequency signals.

[0089] The feeding clock module is used to provide power and clock signals for the radio frequency receiving module.

[0090] The sampling signal selection module comprises N 2xF radio frequency switch matrices, each of which is used to divide the Ka-band sampling intermediate frequency signals into F Ka-band sampling intermediate frequency sub-signals, divide the Ku-band sampling intermediate frequency signals into F Ku-band sampling intermediate frequency sub-signals, and select the fth Ku-band sampling intermediate frequency sub-signal or the fth Ka-band sampling intermediate frequency sub-signal based on the working frequency band of the fth satellite terminal.

[0091] The signal processing module comprises F signal processing units, and the fth signal processing unit is used to perform interference cancellation on the fth satellite communication signal through an adaptive filtering algorithm based on N target frequency band sampling intermediate frequency sub-signals input by the N 2xF radio frequency switch matrices, to obtain an interference cancellation output signal without interference, and the frequency band of the target frequency band sampling intermediate frequency sub-signal is the same as the working frequency band of the fth satellite terminal.

[0092] Wherein, the fth satellite communication signal is a satellite communication signal of the fth satellite terminal, the value of f is 1 to F, N, f and F are positive integers.

[0093] Wherein, the first input port of the signal processing unit receives N target frequency band sampling intermediate frequency sub-signals output by the sampling signal selection unit, and the second input port receives the fth satellite communication signal output by the output port of the satellite communication radio frequency switch matrix of the satellite ground station. The fth satellite communication signal is collected by the satellite antenna, down-converted to baseband or low intermediate frequency by the Ka / Ku band down-conversion module, and input to the fth signal processing unit by the output port of the satellite communication radio frequency switch matrix.

[0094] The interference cancellation device for the Ka and Ku band multi-mode satellite communication ground station provided in the embodiment of the present application is connected between the output port of the RF switch matrix of the satellite communication ground station and the input ports of different satellite communication terminals, and is suitable for the satellite communication ground station that realizes Ka / Ku dual-band multi-mode communication by sharing the satellite communication antenna through the RF switch matrix; the polarization direction of the sampled received signals in the Ka and Ku bands is selected in the RF receiving module, and the frequency band of the sampled received signals is selected in the sampling signal selection module, so that independent signal processing units can be used to process satellite communication signals in different modes, thereby realizing the mutual decoupling of anti-interference processing between different satellite communication terminals.

[0095] Figure 2 is a schematic diagram of the structure of the sampling antenna unit provided in the embodiment of the present application, such as Figure 2 As shown, each sampling antenna unit includes two sampling antenna subunits, each of which operates in different frequency bands: a Ku-band sampling antenna subunit and a Ka-band sampling antenna subunit. Optionally, each sampling antenna subunit includes two polarization output ports: the Ku-band sampling antenna subunit includes a horizontal orthogonal polarization output port and a vertical orthogonal polarization output port, which output horizontal orthogonal polarization sampling signals and vertical orthogonal polarization sampling signals, respectively; and the Ka-band sampling antenna subunit includes a right-hand polarization output port and a left-hand polarization output port, which output right-hand polarization sampling signals and left-hand polarization sampling signals, respectively.

[0096] Optionally, the N sampling antenna units are arranged in a distributed manner, the N sampling antenna units are evenly distributed in a circle, and the angle between adjacent sampling antenna units is 360 / N degrees.

[0097] Optionally, the N sampling antenna units are evenly divided into M sampling antenna subarrays, where M is a positive integer and a divisor of N. The N sampling antenna units are evenly distributed with the geometric center of all the sampling antenna subarrays as the center of the circle.

[0098] The interference cancellation device for the Ka- and Ku-band multi-mode satellite communication ground station provided in the embodiment of the present application adopts an independent Ku- and Ka-band sampling antenna design scheme, and each sampling antenna subunit can have horizontal and vertical polarization, or left-hand and right-hand polarization, including the main polarization modes of Ku- and Ka-band satellite communication; and the sampling antenna adopts a distributed arrangement, which can better solve the problem of obstruction by objects around the antenna in practice.

[0099] Figure 3 This is a structural diagram of the radio frequency receiving component group provided in an embodiment of the present application. Figure 3As shown, each radio frequency receiving component group includes 2 radio frequency receiving components, which are Ku frequency band radio frequency receiving components and Ka frequency band radio frequency receiving components respectively. Each radio frequency receiving component includes 2 pre-selected band pass filters, 2 low noise amplifiers (referred to as low noise amplifiers for short), a radio frequency switch, a down converter and a multiplexer. Specifically, the input ports of the 2 pre-selected band pass filters are connected to the 2 polarized output ports of the sampling antenna subunit of the same frequency band respectively, the output ports are connected to the input ports of the corresponding low noise amplifiers, and are used to filter out the signals of non-working frequency bands received by the sampling antenna subunit. The output ports of the 2 low noise amplifiers are connected to the 2 input ports of the radio frequency switch respectively, and are used to amplify the input sampling signals with low noise. The output port of the radio frequency switch is connected to the input port of the down converter, and is used to select the polarization direction of the sampling signal based on the polarization mode of the satellite communication antenna under the same frequency band of the sampling signal. The output port of the down converter is connected to the intermediate frequency input port of the multiplexer, and is used to down-convert the sampling signal to an intermediate frequency.

[0100] For the nth radio frequency receiving component group:

[0101] In the Ku frequency band radio frequency receiving component, the 2 pre-selected band pass filters receive the horizontal orthogonal polarization sampling signals and the vertical orthogonal polarization signals output by the horizontal orthogonal polarization output port and the vertical orthogonal polarization output port of the Ku frequency band sampling antenna subunit in the nth sampling antenna unit respectively, and transmit the horizontal orthogonal polarization sampling signals and the vertical orthogonal polarization signals to the two low noise amplifiers after filtering out the signals of non-working frequency bands. The low noise amplifiers amplify the signals with low noise and then transmit the signals to the radio frequency switch. The radio frequency switch selects the horizontal orthogonal polarization sampling signals or the vertical orthogonal polarization signals, and outputs the horizontal orthogonal polarization sampling signals or the vertical orthogonal polarization signals to the down converter. The down converter down-converts the horizontal orthogonal polarization sampling signals or the vertical orthogonal polarization signals to an intermediate frequency, and outputs the Ku frequency band sampling intermediate frequency signals to the multiplexer. The intermediate frequency input port of the multiplexer receives the Ku frequency band sampling intermediate frequency signals output by the down converter, the direct current output port is connected to the power input ports of the low noise amplifiers, the radio frequency switch and the down converter respectively, the reference clock output port is connected to the reference clock input port of the down converter, and the synthesis port transmits the intermediate frequency signals to the feed clock module.

[0102] In the Ka-band RF receiving component, two pre-selected bandpass filters respectively receive the right-hand polarized sampling signal and the left-hand polarized sampling signal outputted from the right-hand polarized output port and the left-hand polarized output port of the Ka-band sampling antenna subunit in the nth sampling antenna unit, filter out the signals in the non-working frequency band, and transmit them to two low-noise amplifiers respectively. The low-noise amplifiers perform low-noise amplification processing on the signals and then transmit them to the RF switch. The RF switch selects the right-hand polarized sampling signal and the left-hand polarized sampling signal, and outputs the right-hand polarized sampling signal or the left-hand polarized sampling signal to the down-converter. The down-converter down-converts the right-hand polarized sampling signal or the left-hand polarized sampling signal to an intermediate frequency, and outputs the Ka-band sampling intermediate frequency signal to the multiplexer. The intermediate frequency input port of the multiplexer receives the Ka-band sampled intermediate frequency signal output by the down converter. The DC output port is connected to the low-noise amplifier, the RF switch and the power input port of the down converter respectively. The reference clock output port is connected to the reference clock input port of the down converter. The synthesis port transmits the intermediate frequency signal to the feed clock module.

[0103] The interference cancellation device for the Ka and Ku band multi-mode satellite communication ground station provided in the embodiment of the present application adds RF receiving components of different frequency bands, filters out signals of non-working frequency bands in the sampled signal through a pre-bandpass filter, and uses an RF switch to select the polarization direction of the sampled signal.

[0104] Figure 4 This is a structural diagram of the power and clock feeding module provided in the embodiment of the present application. Figure 4 As shown, the power and clock feed module includes N power and clock feed units, a crystal oscillator, a power amplifier, and a multi-channel power splitter. Each power and clock feed unit includes two bias tweezers and two duplexers. The two bias tweezers are Ku-band bias tweezers and Ka-band bias tweezers, respectively, and the two duplexers are Ku-band duplexers and Ka-band duplexers, respectively.

[0105] The crystal oscillator is used to provide a clock signal; the power amplifier is used to amplify the power of the clock signal output by the crystal oscillator; the multi-way power divider is used to divide the clock signal after power amplification into 2N ways and provide them to N feeding and clock feeding units.

[0106] For the nth power and clock feeding unit:

[0107] The RF and DC ports of the two bias switches are connected to the output ports of the Ku-band RF receiving component and the Ka-band RF receiving component in the nth RF receiving component group to receive the Ku-band sampled intermediate frequency signal and the Ka-band sampled intermediate frequency signal; the first DC port is connected to the RF and clock ports of the duplexer, and the second DC port is connected to an external power supply.

[0108] The radio frequency ports of the two duplexers are connected to the input port of the sampling signal selection unit to output the sampled intermediate frequency signal, and the clock port is connected to the output port of the multi-channel power divider.

[0109] Figure 5 is a structural schematic diagram of a sampling signal selection module provided by an embodiment of the present application, as shown in Figure 5 The sampling signal selection module includes N 2xF radio frequency switch matrices. The nth 2xF radio frequency switch matrix receives Ku-band sampling intermediate frequency signals and Ka-band sampling intermediate frequency signals output by the nth radio frequency receiving component group / the nth feed clock unit, divides the Ku-band sampling intermediate frequency signals into F Ku-band sampling intermediate frequency sub-signals, divides the Ka-band sampling intermediate frequency signals into F Ka-band sampling intermediate frequency sub-signals, and performs frequency band selection on the Ku-band sampling intermediate frequency sub-signals and the Ka-band sampling intermediate frequency sub-signals based on the working frequency band of the satellite communication terminal, and finally outputs F paths of sampling intermediate frequency sub-signals to respective satellite communication terminals. Each signal processing unit receives N paths of sampling intermediate frequency sub-signals of the same frequency band output by the N 2xF radio frequency switch matrices, and the N paths of sampling intermediate frequency sub-signals of the same frequency band constitute the sampling signals corresponding to the signal processing unit.

[0110] Figure 6 is a structural schematic diagram of a 2xF radio frequency switch matrix provided by an embodiment of the present application, as shown in Figure 6 Each 2xF radio frequency switch matrix includes two low-noise amplifiers, two F-path power dividers, and F input radio frequency switches.

[0111] Specifically, the two low-noise amplifiers are a Ku-band low-noise amplifier and a Ka-band low-noise amplifier, which are used to amplify the sampling intermediate frequency signals output by the radio frequency receiving components of the corresponding frequency band. The two F-path power dividers are a Ku-band power divider and a Ka-band power divider, which are used to divide the amplified sampling intermediate frequency signals into F paths of sampling intermediate frequency sub-signals. Each input radio frequency switch receives one path of Ku-band sampling intermediate frequency sub-signals and one path of Ka-band sampling intermediate frequency sub-signals, performs frequency band selection based on the working frequency band of the corresponding satellite communication terminal, and outputs one path of Ku-band sampling intermediate frequency sub-signals or one path of Ka-band sampling intermediate frequency sub-signals to the signal processing unit corresponding to the satellite communication terminal.

[0112] In the nth 2xF radio frequency switch matrix:

[0113] The input port of the low-noise amplifier receives the sampling intermediate frequency signals output by the nth radio frequency receiving component group, and the output port is connected to the input port of the power divider to amplify the sampling intermediate frequency signals. The F output ports of the power divider are respectively connected to the input ports of the F input radio frequency switches to divide the amplified sampling intermediate frequency signals into F paths of sampling intermediate frequency sub-signals.

[0114] Specifically, the input port of the Ku-band low-noise amplifier receives a Ku-band sampling intermediate frequency signal output by a Ku-band radio frequency receiving component in the nth radio frequency receiving component group, and the output port is connected with the input port of the Ku-band power divider to amplify the Ku-band sampling intermediate frequency signal; the F output ports of the Ku-band power divider are respectively connected with the first input ports of the F input radio frequency switches to divide the Ku-band sampling intermediate frequency signal into F Ku-band sampling intermediate frequency sub-signals.

[0115] The input port of the Ka-band low-noise amplifier receives a Ka-band sampling intermediate frequency signal output by a Ka-band radio frequency receiving component in the nth radio frequency receiving component group, and the output port is connected with the input port of the Ka-band power divider to amplify the Ka-band sampling intermediate frequency signal; the F output ports of the Ka-band power divider are respectively connected with the second input ports of the F input radio frequency switches to divide the Ka-band sampling intermediate frequency signal into F Ka-band sampling intermediate frequency sub-signals.

[0116] The fth input radio frequency switch selects a frequency band based on the working frequency band of the fth satellite communication terminal, and outputs the Ku-band sampling intermediate frequency sub-signal or the Ka-band sampling intermediate frequency sub-signal to the fth signal processing unit.

[0117] The interference cancellation device of the Ka and Ku-band multi-mode satellite communication ground station provided by the embodiment of the present application adds a sampling signal selection module, performs sub-band division and frequency band selection on the sampling intermediate frequency signal, so that the frequency band of the N sampling intermediate frequency sub-signals received by the signal processing unit corresponding to each satellite communication terminal is the same as the satellite communication terminal, thereby enabling the independent signal processing unit to process the satellite communication signals in different modes, and realizing the mutual decoupling of the anti-interference processing between different satellite communication terminals.

[0118] Figure 7 is a structural schematic diagram of the signal processing unit provided by the embodiment of the present application, as shown in Figure 7 The signal processing unit includes N+1 down converters, N+1 analog-to-digital converters, a digital signal processing unit, a digital-to-analog converter and an up converter.

[0119] Specifically, the downconverter is used to downconvert the sampled intermediate frequency sub-signal of the target frequency band to baseband or low intermediate frequency, outputting the sampled baseband sub-signal or sampled low intermediate frequency sub-signal, or downconvert the satellite communication signal to baseband or low intermediate frequency, outputting the satellite communication baseband signal or satellite communication low intermediate frequency signal. The analog-to-digital converter is used to convert the sampled baseband sub-signal or sampled low intermediate frequency sub-signal into a sampled digital sub-signal of the target frequency band, or convert the satellite communication baseband signal or satellite communication low intermediate frequency signal into a satellite communication digital signal. The digital signal processing unit is used to perform interference cancellation on the satellite communication digital signal using an adaptive filtering algorithm based on the N target frequency band sampled digital sub-signals, thereby obtaining an interference cancellation signal in the digital domain. The digital-to-analog converter is used to convert the interference cancellation signal in the digital domain into an analog baseband signal or an analog low intermediate frequency signal. The upconverter is used to upconvert the analog baseband signal or analog low intermediate frequency signal to an intermediate frequency and output it as the interference cancellation output signal corresponding to the f-th satellite communication terminal.

[0120] In the f-th signal processing unit:

[0121] The input ports of the 1st to Nth downconverters are respectively connected to the output ports of the fth input RF switches in the N 2×F RF switch matrices, and the output ports are respectively connected to the 1st to Nth analog-to-digital converters, down-converting the input N target frequency band sampled intermediate frequency sub-signals (N target frequency band sampled intermediate frequency sub-signals constitute the fth sampled signal) to baseband or low intermediate frequency, and outputting N sampled baseband sub-signals or sampled low intermediate frequency sub-signals, where the target frequency band is the frequency band of the fth satellite communication terminal; the input port of the N+1th downconverter receives the fth satellite communication signal corresponding to the fth satellite communication terminal, and the output port is connected to the input port of the N+1th analog-to-digital converter, down-converting the fth satellite communication signal to baseband or low intermediate frequency, and outputting 1 satellite communication baseband signal or satellite communication low intermediate frequency signal.

[0122] The output ports of the 1st to Nth analog-to-digital converters are respectively connected to the 1st to Nth input ports of the digital signal processing unit to convert the N-channel sampled baseband sub-signals or sampled low-intermediate-frequency sub-signals into N-channel target frequency band sampled digital sub-signals; the output port of the N+1th analog-to-digital converter is connected to the N+1th input port of the digital signal processing unit to convert the satellite communication baseband signal or satellite communication low-intermediate-frequency signal into a satellite communication digital signal.

[0123] The output port of the digital signal processing unit is connected to the input port of the digital-to-analog converter. Based on the N-channel target frequency band sampling digital sub-signals, the satellite communication digital signal is interfered with through the adaptive filtering algorithm to obtain the interference cancellation signal in the digital domain.

[0124] The output port of the digital-to-analog converter is connected to the input port of the up-converter, performs digital-to-analog conversion on the interference cancellation signal in the digital domain, and outputs an analog baseband signal or an analog low intermediate frequency signal.

[0125] The up-converter up-converts the analog baseband signal or the analog low intermediate frequency signal output by the digital-to-analog converter to an intermediate frequency and outputs it as the interference cancellation output signal corresponding to the f-th satellite communication terminal.

[0126] Figure 8 Schematic diagram of the structure of the digital signal processing unit provided in the embodiment of the present application. Figure 8 As shown, the digital signal processing unit includes a delayer, a main beamformer, a weight updater, a weight filter and a slave beamformer.

[0127] The delayer is used to delay the input N-channel target frequency band sampled digital sub-signals and output N-channel space-time auxiliary antenna receiving signals. The main beamformer is used to determine the initial weights of the N-channel space-time auxiliary antenna receiving signals, perform weighted processing on the N-channel space-time auxiliary antenna receiving signals based on the initial weights after smooth filtering, and synthesize them with the f-th satellite communication signal to output the initial interference cancellation signal. The weight updater is used to output updated weights using an adaptive filtering algorithm based on the N-channel space-time auxiliary antenna receiving signals and the initial interference cancellation signal output by the main beamformer. Optionally, the weight updater allows the use of an adaptive filtering algorithm with a larger step size to improve the convergence speed of the algorithm. The weight filter is used to smooth filter the weights updated by the weight updater and output the final weights. The slave beamformer is used to perform weighted processing on the N-channel space-time auxiliary antenna receiving signals based on the final weights and synthesize them with the f-th satellite communication signal to output the interference cancellation signal.

[0128] Specifically, in the digital signal processing unit of the f-th signal processing unit, the N target frequency band sampled digital sub-signals x(n) = [x1(n), ..., x N (n)] T (corresponding to N auxiliary antenna receiving signals) delay processing is performed through the delay device to obtain N-way space-time auxiliary antenna receiving signals c(n) = [x T (n),x T (n-1),…,x T (n-L+1)] T , where L is the maximum delay; the main beamformer calculates the initial weights of the N-way space-time auxiliary antenna receiving signals c(n), performs weighted processing on the N-way space-time auxiliary antenna receiving signals c(n) based on the initial weights and synthesizes them with the f-th satellite communication signal, and outputs the initial interference cancellation signal e m (n); In the weight updater, based on the initial interference cancellation signal e m (n) and N-channel target frequency band target frequency band sampled digital sub-signals x(n), using adaptive filtering algorithm to output updated weights w m (n); In the weight filter, update the weight w m(n) Perform smoothing filtering to obtain the final weight w after frequency filtering s (n); In the slave beamformer, using w s (n) Perform weighted processing on the N-way space-time auxiliary antenna receiving signal c(n) and synthesize it with the f-th satellite communication signal d(n) (corresponding to the main antenna receiving signal), and output the interference cancellation signal e of the f-th satellite communication signal s (n).

[0129] The interference cancellation device for a multi-mode satellite communication ground station in the Ka and Ku bands provided in an embodiment of the present application provides a master-slave structure beamformer. The master beamformer first calculates initial weights and uses the initial weights after smoothing filtering to perform weighted synthesis to obtain an initial interference cancellation signal. Then, the weight updater uses an adaptive filtering algorithm based on the space-time auxiliary antenna received signal and the initial interference cancellation signal, and the updated weights are filtered and smoothed to obtain final weights. Finally, the slave beamformer uses the final weights to perform weighted synthesis to obtain the final interference cancellation signal. On the one hand, since the final weights after smoothing filtering have a smaller error, the steady-state error of the output signal of the slave beamformer is reduced, thereby reducing the problem of increased steady-state error caused by the large step size of the adaptive filtering algorithm. On the other hand, since the master beamformer weight update allows the use of an adaptive filtering algorithm with a larger step size, the algorithm can be guaranteed to have a faster convergence speed. On the other hand, since the slave beamformer is not in the feedback loop of the adaptive filtering algorithm, it does not affect the stability of the adaptive filtering algorithm.

[0130] Figure 9 is a flow chart of the interference cancellation method for the Ka and Ku band multi-mode satellite communication ground station provided in the embodiment of the present application, such as Figure 9 As shown, the execution subject is the interference cancellation device in the above embodiment, and the method includes at least the following steps:

[0131] S901. Collect N groups of Ku-band sampling signals and Ka-band sampling signals from space;

[0132] S902: Selecting a polarization direction of the Ku-band sampled signal based on the polarization mode of the satellite communication antenna in the Ku band, selecting a polarization direction of the Ka-band sampled signal based on the polarization mode of the satellite communication antenna in the Ka band, and converting the collected Ku-band sampled signal into a Ku-band sampled intermediate frequency signal, and converting the collected Ka-band sampled signal into a Ka-band sampled intermediate frequency signal.

[0133] S903: Divide the Ku-band sampled intermediate frequency signal into F Ku-band sampled intermediate frequency sub-signals, divide the Ka-band sampled intermediate frequency signal into F Ka-band sampled intermediate frequency sub-signals, and select the f-th Ku-band sampled intermediate frequency sub-signal or the f-th Ka-band sampled intermediate frequency sub-signal based on the operating frequency band of the f-th satellite communication terminal;

[0134] S904: Based on the N target frequency band sampled intermediate frequency sub-signals, perform interference cancellation on the f-th satellite communication signal using an adaptive filtering algorithm to obtain an interference-free interference cancellation output signal;

[0135] The frequency band of the target frequency band sampling intermediate frequency sub-signal is the same as the working frequency band of the f-th satellite communication terminal, the f-th satellite communication signal is the satellite communication signal of the f-th satellite communication terminal, the value of f ranges from 1 to F, and N, f and F are all positive integers.

[0136] In some embodiments, S904 specifically includes:

[0137] Delay processing is performed on N target frequency band sampled digital sub-signals, and N space-time auxiliary antenna reception signals are output, wherein the target frequency band sampled digital sub-signals are obtained by down-converting and analog-to-digital converting the target frequency band sampled intermediate frequency sub-signals;

[0138] Determine the initial weights of the N-way space-time auxiliary antenna receiving signals, perform weighted processing on the N-way space-time auxiliary antenna receiving signals based on the initial weights after smoothing filtering, synthesize them with the f-th satellite communication signal, and output an initial interference cancellation signal;

[0139] Based on the N-way space-time auxiliary antenna receiving signal and the initial interference cancellation signal, an adaptive filtering algorithm is used to output the updated weights;

[0140] Perform smoothing filtering on the updated weights and output the final weights;

[0141] Based on the final weights, the N-way space-time auxiliary antenna receiving signals are weighted and synthesized with the f-th satellite communication signal to output an interference cancellation signal.

[0142] In some embodiments, the smoothing filter specifically satisfies:

[0143] w s (n)=1 / K(w m (n)+w m (n-1)+,…,w m (n-K+1))

[0144] Among them, w s (n) is the final weight after smoothing filtering, K is the length of the sliding window, w m (n)+w m (n-1)+,…,w m(n-K+1) is the sum of the initial weights updated from the nth to n-K+1th iterations.

[0145] In some embodiments, the smoothing filter specifically satisfies:

[0146] w s (n) = b × w s (n)+(1-b)w m (n)

[0147] Among them, w s (n) is the final weight after smoothing filtering, b is the forgetting factor, w m (n) is the initial weight obtained by the nth iteration update.

[0148] In some embodiments, the forgetting factor b satisfies:

[0149] b=1-2 -M

[0150] Wherein, M is a positive integer.

[0151] It should be understood that the method in the above embodiment is executed by the device in the above device embodiment, and its implementation principle and technical effect are similar to those described in the above device embodiment. The corresponding process in the method can refer to the working process of the above device, which will not be repeated here.

[0152] The technical solution provided in the embodiment of the present application is further illustrated below through a specific example.

[0153] Assume that the interference signal is a Gaussian white noise signal; in this interference cancellation method: the weighted filtering adopts a sliding average, K=100; the step size factor of the adaptive filtering algorithm is 1e-3.

[0154] First, assuming the receive interference-to-noise ratio (IRR) of the main antenna and the auxiliary antenna is 30 dB, the step size is relatively large.

[0155] Figure 10 : is a schematic diagram comparing the mean square error of the output signal of the LMS algorithm provided in the embodiment of the present application and the method of the present application, as shown in FIG. Figure 10 As shown in FIG, the error signal curve is obtained by averaging 100 Monte Carlo simulations. It can be seen that the steady-state mean square error of the method of the present application is about 5 dB lower than that of the traditional LMS algorithm, and the convergence curve is smoother.

[0156] Then, assuming that the receive interference-to-noise ratio of the main antenna and the auxiliary antenna is 30 dB, the step size is relatively small. Figure 11 : is a schematic diagram comparing the mean square error of the output signal of the LMS algorithm provided in the embodiment of the present application and the method of the present application, as shown in FIG. Figure 11As shown, the error signal curve is obtained by averaging 100 Monte Carlo simulations. It can be seen that the convergence curve of the method of the present application overlaps with that of the traditional LMS algorithm, so the convergence characteristics and steady-state characteristics are basically the same.

[0157] It can be concluded that the method of the present application can significantly reduce the steady-state error when the iterative step size is relatively large, while having the same performance as the existing method when the step size is relatively small.

[0158] It will be understood that the various numerical numbers involved in the embodiments of the present application are merely distinctions for the convenience of description and are not intended to limit the scope of the embodiments of the present application.

[0159] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An interference cancellation device for a Ka and Ku band multi-mode satellite communication ground station, characterized in that: The interference cancellation device is connected between the output port of the radio frequency switch matrix of the satellite communication ground station and the input ports of different satellite communication terminals; The interference cancellation device includes: A sampling antenna module, comprising N sampling antenna units, wherein the sampling antenna units are used to collect Ku-band sampling signals and Ka-band sampling signals from space; a radio frequency receiving module, comprising N radio frequency receiving component groups, the radio frequency receiving component groups comprising a Ku-band radio frequency receiving component and a Ka-band radio frequency receiving component, configured to select a polarization direction of the Ku-band sampled signal based on a polarization mode of the satellite communication antenna in the Ku band, select a polarization direction of the Ka-band sampled signal based on a polarization mode of the satellite communication antenna in the Ka band, and convert the collected Ku-band sampled signal into a Ku-band sampled intermediate frequency signal, and convert the collected Ka-band sampled signal into a Ka-band sampled intermediate frequency signal; a sampling signal selection module, comprising N 2×F radio frequency switch matrices, the 2×F radio frequency switch matrices being configured to divide the Ku-band sampled intermediate frequency signal into F Ku-band sampled intermediate frequency sub-signals, divide the Ka-band sampled intermediate frequency signal into F Ka-band sampled intermediate frequency sub-signals, and select the f-th Ku-band sampled intermediate frequency sub-signal or the f-th Ka-band sampled intermediate frequency sub-signal based on an operating frequency band of the f-th satellite communication terminal; A signal processing module, comprising F signal processing units, the fth signal processing unit being configured to perform interference cancellation on the fth satellite communication signal using an adaptive filtering algorithm based on N target frequency band sampled intermediate frequency sub-signals input by the N 2×F radio frequency switch matrices, thereby obtaining an interference-free interference cancellation output signal; The frequency band of the target frequency band sampled intermediate frequency sub-signal is the same as the operating frequency band of the f-th satellite communication terminal, the f-th satellite communication signal is the satellite communication signal of the f-th satellite communication terminal, the value of f ranges from 1 to F, and N, f and F are all positive integers; The 2×F RF switch matrix includes: 2 low noise amplifiers, 2 power splitters and F input RF switches; The low noise amplifier is used to amplify the input sampled intermediate frequency signal; The power divider is used to divide the amplified sampled intermediate frequency signal into F-channel sampled intermediate frequency sub-signals; The input radio frequency switch is used to select the sampled intermediate frequency sub-signals of different frequency bands input by the two power dividers based on the working frequency band of the satellite communication terminal.

2. The interference cancellation device for a Ka and Ku band multi-mode satellite communication ground station according to claim 1, characterized in that: The signal processing unit includes a digital signal processing unit, and the digital signal processing unit includes a delayer, a main beamformer, a weight updater, a weight filter and a slave beamformer; The delay device is used to delay the input N-channel target frequency band sampled digital sub-signals and output N-channel space-time auxiliary antenna received signals, wherein the target frequency band sampled digital sub-signals are obtained by down-converting and analog-to-digital converting the target frequency band sampled intermediate frequency sub-signals; The main beamformer is used to determine the initial weights of the N-way space-time auxiliary antenna receiving signals, perform weighted processing on the N-way space-time auxiliary antenna receiving signals based on the initial weights after smoothing filtering, synthesize them with the f-th satellite communication signal, and output an initial interference cancellation signal; The weight updater is used to output updated weights using an adaptive filtering algorithm based on the N-way space-time auxiliary antenna received signals and the initial interference cancellation signal; The weight filter is used to perform smooth filtering on the updated weights and output a final weight; The slave beamformer is used to perform weighted processing on the N space-time auxiliary antenna reception signals based on the final weight value and synthesize them with the f-th satellite communication signal, and output an interference cancellation signal in the digital domain.

3. The interference cancellation device for a Ka and Ku band multi-mode satellite communication ground station according to claim 1 or 2, characterized in that: The signal processing unit includes N+1 down-converters, N+1 analog-to-digital converters, a digital signal processing unit, a digital-to-analog converter, and an up-converter; The down-converter is used to down-convert the sampled intermediate frequency sub-signal of the target frequency band to baseband or low intermediate frequency, and output the sampled baseband sub-signal or the sampled low intermediate frequency sub-signal, or to down-convert the satellite communication signal to baseband or low intermediate frequency, and output the satellite communication baseband signal or the satellite communication low intermediate frequency signal; The analog-to-digital converter is used to convert the sampled baseband sub-signal or the sampled low intermediate frequency sub-signal into a target frequency band sampled digital sub-signal, or to convert the satellite communication baseband signal or the satellite communication low intermediate frequency signal into a satellite communication digital signal; The digital signal processing unit is used to sample digital sub-signals based on N target frequency bands, perform interference cancellation on the satellite communication digital signal through an adaptive filtering algorithm, and obtain an interference cancellation signal in the digital domain; The digital-to-analog converter is used to convert the interference cancellation signal in the digital domain into an analog baseband signal or an analog low intermediate frequency signal; The up-converter is used to up-convert the analog baseband signal or the analog low intermediate frequency signal to an intermediate frequency and output it as the interference cancellation output signal corresponding to the f-th satellite communication terminal.

4. The interference cancellation device for a Ka and Ku band multi-mode satellite communication ground station according to claim 3, characterized in that: In the f-th signal processing unit: The input ports of N down-converters in the N+1 down-converters are respectively connected to the output ports of the f-th input RF switch in the N 2×F RF switch matrices, and the output ports are respectively connected to N analog-to-digital converters, for down-converting the input N-channel frequency band sampled intermediate frequency sub-signals to baseband or low intermediate frequency, and outputting N-channel sampled baseband sub-signals or sampled low intermediate frequency sub-signals; the input ports of the down-converters other than the N down-converters receive the f-th satellite communication signal corresponding to the f-th satellite communication terminal, and the output ports are connected to the input ports of the analog-to-digital converters other than the N analog-to-digital converters, for down-converting the f-th satellite communication signal to baseband or low intermediate frequency, and outputting the satellite communication baseband signal or the satellite communication low intermediate frequency signal; The output ports of the N+1 analog-to-digital converters are respectively connected to the N+1 input ports of the digital signal processing unit, the N analog-to-digital converters among the N+1 analog-to-digital converters are used to convert the N channels of sampled baseband sub-signals or sampled low-intermediate-frequency sub-signals into N channels of sampled digital sub-signals of the target frequency band, and the analog-to-digital converters other than the N analog-to-digital converters are used to convert the satellite communication baseband signals or satellite communication low-intermediate-frequency signals into satellite communication digital signals; The output port of the digital signal processing unit is connected to the input port of the digital-to-analog converter, and is used to sample the digital sub-signals based on the N target frequency bands, perform interference cancellation on the satellite communication digital signals through an adaptive filtering algorithm, and obtain an interference cancellation signal in the digital domain; The output port of the digital-to-analog converter is connected to the input port of the up-converter, and is used to perform digital-to-analog conversion on the interference cancellation signal in the digital domain and output an analog baseband signal or an analog low intermediate frequency signal; The up-converter up-converts the analog baseband signal or the analog low intermediate frequency signal to an intermediate frequency and outputs it as the interference cancellation output signal corresponding to the f-th satellite communication terminal.

5. The interference cancellation device for a Ka and Ku band multi-mode satellite communication ground station according to claim 4, characterized in that: The two low noise amplifiers are respectively a Ku-band low noise amplifier and a Ka-band low noise amplifier, and the two power splitters are respectively a Ku-band power splitter and a Ka-band power splitter. In the n-th 2×F radio frequency switch matrix: The input port of the Ku-band low-noise amplifier receives the Ku-band sampled intermediate frequency signal output by the nth RF receiving component group, and the output port is connected to the input port of the Ku-band power splitter to amplify the Ku-band sampled intermediate frequency signal; the F output ports of the Ku-band power splitter are respectively connected to the first input ports of the F input RF switches to split the Ku-band sampled intermediate frequency signal into F Ku-band sampled intermediate frequency sub-signals; The input port of the Ka-band low-noise amplifier receives the Ka-band sampled intermediate frequency signal output by the nth RF receiving component group, and the output port is connected to the input port of the Ka-band power splitter to amplify the Ka-band sampled intermediate frequency signal; the F output ports of the Ka-band power splitter are respectively connected to the second input ports of the F input RF switches to split the Ka-band sampled intermediate frequency signal into F Ka-band sampled intermediate frequency sub-signals; The f-th input RF switch selects the input Ku-band sampled intermediate frequency sub-signal and the input Ka-band sampled intermediate frequency sub-signal based on the operating frequency band of the f-th satellite communication terminal, and outputs the Ku-band sampled intermediate frequency sub-signal or the Ka-band sampled intermediate frequency sub-signal; The value of n ranges from 1 to N.

6. The interference cancellation device for a Ka and Ku band multi-mode satellite communication ground station according to claim 1, characterized in that: The sampling antenna unit includes two sampling antenna subunits, namely a Ka-band sampling antenna subunit and a Ku-band sampling antenna subunit; the Ka-band sampling antenna subunit includes two polarization output ports, which respectively output right-hand polarized sampling signals and left-hand polarized sampling signals; the Ku-band sampling antenna subunit includes two polarization output ports, which respectively output horizontal orthogonal polarization sampling signals and vertical orthogonal polarization sampling signals.

7. The interference cancellation device for a Ka and Ku band multi-mode satellite communication ground station according to claim 6, characterized in that: Each RF receiving component includes two pre-selection bandpass filters, two low-noise amplifiers, RF switches, downconverters and multiplexers; The input ports of the two preselection bandpass filters are respectively connected to the two polarization output ports of the sampling antenna subunit of the same frequency band, and the output ports are respectively connected to the input ports of the two low-noise amplifiers for filtering out the signals of the non-working frequency band received by the sampling antenna subunit; The output ports of the two low-noise amplifiers are respectively connected to the two input ports of the RF switch for performing low-noise amplification on the input sampling signal; The output port of the radio frequency switch is connected to the input port of the down converter, and is used to select the polarization direction of the sampled signal based on the polarization mode of the satellite communication antenna in the same frequency band as the sampled signal; The intermediate frequency output port of the down converter is connected to the intermediate frequency input port of the multiplexer for down-converting the sampled signal to the intermediate frequency; The reference clock output port of the multiplexer is connected to the reference clock input port of the down converter, and the DC output port is connected to the power input port of the low noise amplifier, the radio frequency switch and the down converter respectively.

8. The interference cancellation device for a Ka and Ku band multi-mode satellite communication ground station according to claim 7, characterized in that: The device also includes a power and clock feeding module, the input port of which is connected to the synthesis port of the multiplexer in the RF receiving component, and the output port of which is connected to the input port of the sampling signal selection module, for providing power and clock signals for the RF receiving module.

9. A method for interference cancellation of Ka and Ku band multi-mode satellite communication ground stations, characterized in that: An interference cancellation device applied to a Ka and Ku band multi-mode satellite communication ground station according to any one of claims 1 to 8, comprising: Collecting N groups of Ku-band sampling signals and Ka-band sampling signals from space; Selecting a polarization direction of the Ku-band sampled signal based on the polarization mode of the satellite communication antenna in the Ku band, selecting a polarization direction of the Ka-band sampled signal based on the polarization mode of the satellite communication antenna in the Ka band, and converting the collected Ku-band sampled signal into a Ku-band sampled intermediate frequency signal, and converting the collected Ka-band sampled signal into a Ka-band sampled intermediate frequency signal; dividing the Ku-band sampled intermediate frequency signal into F Ku-band sampled intermediate frequency sub-signals, dividing the Ka-band sampled intermediate frequency signal into F Ka-band sampled intermediate frequency sub-signals, and selecting the f-th Ku-band sampled intermediate frequency sub-signal or the f-th Ka-band sampled intermediate frequency sub-signal based on an operating frequency band of the f-th satellite communication terminal; performing interference cancellation on the f-th satellite communication signal using an adaptive filtering algorithm based on N target frequency band sampled intermediate frequency sub-signals to obtain an interference cancellation output signal free of interference, wherein the frequency band of the target frequency band sampled intermediate frequency sub-signals is the same as the operating frequency band of the f-th satellite communication terminal; The frequency band of the target frequency band sampling intermediate frequency sub-signal is the same as the working frequency band of the f-th satellite communication terminal, the f-th satellite communication signal is the satellite communication signal of the f-th satellite communication terminal, the value of f ranges from 1 to F, and N, f and F are all positive integers.

10. The interference cancellation method for Ka and Ku band multi-mode satellite communication ground stations according to claim 9, characterized in that: The obtaining of the interference cancellation output signal free of interference includes: Delaying N target frequency band sampled digital sub-signals, and outputting N space-time auxiliary antenna received signals, wherein the target frequency band sampled digital sub-signals are obtained by down-converting and analog-to-digital converting the target frequency band sampled intermediate frequency sub-signals; Determine initial weights of the N space-time auxiliary antenna received signals, perform weighted processing on the N space-time auxiliary antenna received signals based on the initial weights after smoothing filtering, synthesize them with the f-th satellite communication signal, and output an initial interference cancellation signal; Based on the N space-time auxiliary antenna received signals and the initial interference cancellation signal, an adaptive filtering algorithm is used to output an updated weight value; Performing smoothing filtering on the updated weights and outputting final weights; The N space-time auxiliary antenna receiving signals are weightedly processed based on the final weights and synthesized with the f-th satellite communication signal to output an interference cancellation signal in the digital domain.

11. The interference cancellation method for a Ka and Ku band multi-mode satellite communication ground station according to claim 10, characterized in that: The smoothing filter specifically satisfies: in, is the final weight after smoothing filtering, is the length of the sliding window, For the times to The sum of the initial weights obtained by iterative updates.

12. The interference cancellation method for a Ka and Ku band multi-mode satellite communication ground station according to claim 10, characterized in that: The smoothing filter specifically satisfies: in, is the final weight after smoothing filtering, For the forgetting factor, For the The initial weights are updated in the iterations.

13. The interference cancellation method for a Ka and Ku band multi-mode satellite communication ground station according to claim 12, characterized in that: The forgetting factor satisfies: in, Is a positive integer.

Images