Adaptive adjustment signal receiving system and method

Abstract

According to the self-adaptive adjustment signal receiving system and method, interference signals are autonomously identified through background signal acquisition and processing, and then parameters such as receiving frequency, bandwidth and gain of a broadband frequency conversion module are adaptively optimized and adjusted to improve the capability of resisting intentional or unintentional interference, so that the bandwidth for receiving and processing the signals can be effectively expanded, and the signal quality is improved. A broadband input signal adaptive adjustment function required by a flexible load communication satellite system is realized, and channelization processing, demodulation, data merging, modulation, digital-to-analog conversion and other functions can be carried out on each signal processing channel. And meanwhile, actions such as analog-to-digital conversion of intermediate-frequency signals, spectrum processing, interference identification, frequency band comparison, adjustment of receiving parameter instruction generation and the like are realized according to the conversion of the working modes.

Description

Technical Field

[0001] The present invention relates to an adaptive signal receiving system and method, belonging to the technical field of satellite receivers and ground communication equipment receiving technology devices. Background Art

[0002] With the rapid development of wireless communication technology, the electromagnetic environment in space has become extremely complex, resulting in intentional or unintentional interference to the normal working channels, thereby reducing the efficiency of wireless communication. On the other hand, in order to solve the problems of traditional satellites with fixed states and low utilization efficiency, flexible payload communication satellites based on software definition need to realize timely adjustment of parameters such as the frequency, bandwidth, and gain of received signals.

[0003] However, the receivers of traditional communication systems can only passively and manually adjust working parameters. Even most transparent transponder receivers used for satellite communication do not have the ability to flexibly adjust parameters such as the receiving frequency band, bandwidth, and gain. Moreover, the receiving bandwidth of traditional receivers is too large, and the accumulated background noise results in a low signal-to-noise ratio, making it impossible to fully exploit the potential of communication systems. Summary of the Invention

[0004] The technical problem solved by the present invention is: aiming at the problems in the current existing technologies, such as the fixed state of traditional satellites and low utilization efficiency, an adaptive signal receiving system and method are proposed.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] An adaptive signal receiving system includes a power splitting module, a broadband frequency conversion module, and a processing and control module. The broadband frequency conversion module and the processing and control module form a signal processing channel, and the input ends of each signal processing channel are connected to the output end of the power splitting module, where:

[0007] The power splitting module receives an externally input ultra-wideband signal, performs power splitting processing into N radio frequency signals and sends them to each signal processing channel;

[0008] The broadband frequency conversion module receives a single radio frequency signal after power splitting processing by the power splitting module, performs low-noise amplification, filtering, gain control, and frequency conversion processing respectively to obtain a single intermediate frequency signal, amplifies it and outputs it to the processing and control module of the signal processing channel where it is located; at the same time, it receives the frequency band adjustment instructions sent back by the processing and control modules of the current signal processing channel and the next signal processing channel, adjusts the frequency band of the frequency conversion processing, and then amplifies and outputs the single intermediate frequency signal to the processing and control module of the signal processing channel where it is located;

[0009] The processing control module receives the single-channel intermediate frequency signal sent by the broadband frequency conversion module, converts it into a digital signal, performs real-time Fourier transform processing on the digital signal, and performs frequency-domain smoothing filtering on the signal after Fourier transform processing to obtain the data signal after spectrum processing for realizing the monitoring of the dynamic change of the spectrum. At the same time, it demodulates the digital signal; it performs interference recognition and spectrum hole detection on the data signal after spectrum processing, judges the working frequency band after obtaining the processing result, and determines the working frequency band of the data signal to be adjusted according to the judgment result; according to the working mode of the current processing control module, it combines and processes the demodulated digital signal and the data signal after spectrum processing and outputs them externally or generates a frequency band adjustment instruction according to the working frequency band of the data signal to be adjusted and returns it to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel.

[0010] Among them, the working modes of the receiving system include the spectrum detection processing mode and the channelization processing mode, and the working modes of the processing control modules of each signal processing channel are set independently.

[0011] The broadband frequency conversion module includes a low-noise amplifier, a switched filter, a digital control attenuator, a tunable local oscillator frequency converter, and an intermediate frequency amplifier, where:

[0012] The low-noise amplifier performs low-noise amplification processing on the single-channel radio frequency signal according to the noise requirements of the signal processing channel, and sends the signal after low-noise amplification processing to the switched filter;

[0013] The switched filter receives the signal after low-noise amplification processing and adjusts the working frequency band and bandwidth, and sends the adjusted signal to the digital control attenuator;

[0014] The digital control attenuator receives the adjusted signal and adjusts the signal gain;

[0015] The tunable local oscillator frequency converter performs down-conversion processing on the analog signal after the signal gain adjustment delivered by the digital control attenuator and sends it to the intermediate frequency amplifier;

[0016] The intermediate frequency amplifier receives the signal after down-conversion processing and amplifies and outputs it as a single-channel intermediate frequency signal.

[0017] The low-noise amplifier, the switched filter, the digital control attenuator, the tunable local oscillator frequency converter, and the intermediate frequency amplifier all receive the frequency band adjustment instruction returned by the processing control module of the current signal processing channel, and adjust the signal adjustment parameters of each part according to the frequency band adjustment instruction.

[0018] The processing control module includes an ADC, an FPGA-A, an FPGA-B, a DAC, and a DSP, where:

[0019] The ADC receives the single-channel intermediate frequency signal sent by the broadband frequency conversion module and converts it into a digital signal;

[0020] FPGA-A receives a single-channel digital signal, performs down-conversion processing and then demodulation; performs real-time Fourier transform processing and frequency-domain smoothing filtering processing on the single-channel digital signal to obtain a spectrum-processed data signal, and sends the spectrum-processed data signal to the DSP; performs channelization processing and demodulation on the digital signal and then sends it to FPGA-B;

[0021] The DSP receives the spectrum-processed data signal for interference recognition and spectrum hole detection, judges the working frequency band after obtaining the processing result, and determines the working frequency band of the data signal to be adjusted according to the judgment result;

[0022] FPGA-B receives the spectrum-processed data signal and the demodulated signal for merging processing, and at the same time generates a frequency band adjustment instruction according to the working frequency band of the data signal to be adjusted determined by the DSP and returns it to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel;

[0023] The DAC receives the merged and modulated digital signal, performs conversion and then outputs.

[0024] The FPGA-A includes an FFT, a spectrum processing unit, a channelization processing unit, and a demodulation unit, where:

[0025] The FFT receives the single-channel digital signal sent by the ADC, performs real-time Fourier transform processing, and then sends it to the spectrum processing unit;

[0026] The spectrum processing unit receives the digitally transformed signal after real-time Fourier transform processing and performs frequency-domain smoothing filtering processing to obtain a spectrum-processed data signal;

[0027] The channelization processing unit performs channelization processing on the single-channel digital signal and then sends it to the demodulation unit;

[0028] The demodulation unit demodulates the signal after down-conversion processing and then sends it to FPGA-B.

[0029] The FPGA-B includes a frequency band comparison and adjustment unit, a data merging unit, and a modulation unit, where:

[0030] The frequency band comparison and adjustment unit receives the working frequency band of the data signal output by the DSP, determines the working frequency band of the data signal to be adjusted determined by the DSP, generates a frequency band adjustment instruction, and returns it to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel;

[0031] The data merging unit receives the spectrum-processed data signal and the demodulated signal, performs merging processing, and then sends it to the modulation unit;

[0032] The modulation unit receives the digitally merged signal and sends it to the DAC.

[0033] After the broadband frequency conversion module of each signal processing channel realizes self - adjustment according to the frequency band adjustment instruction sent by the processing control module of the signal processing channel where it is located, the frequency band and bandwidth of each signal processing channel are jointly controlled through the frequency band adjustment instruction sent by the processing control module of other signal processing channels.

[0034] External DDR3 memories are set for the FPGA - A, FPGA - B, and DSP. Two DDR3 memories are externally attached to each of the FPGA - A and FPGA - B to realize data caching and format conversion; two DDR3 memories are externally attached to each DSP to realize data transmission after spectrum processing. Each DDR3 memory uses a GTH interface to realize data transmission.

[0035] An adaptive adjustment signal receiving method implemented according to a receiving system includes:

[0036] The received ultra - wideband input signal is power - divided into N single - path radio frequency signals, and after the signal level is processed by the LNA, it is sent to the broadband frequency conversion module.

[0037] The working frequency band and bandwidth of each single - path radio frequency signal are selected and switched by a switch filter, the signal gain is adjusted by a digital control attenuator, frequency conversion processing is realized by a tunable local oscillator frequency converter, and the intermediate - frequency signal is amplified by an intermediate - frequency amplifier and output to the processing control module.

[0038] The analog - to - digital conversion is completed by the ADC, and the input is sent to the FPGA - A to complete real - time fast Fourier transform processing and digital signal frequency - domain smoothing filtering processing. The dynamic change of the spectrum is monitored through digital signal time - frequency analysis to obtain the monitoring result.

[0039] If the working mode of the current processing control module is the spectrum monitoring processing mode, the data after spectrum processing is transmitted to the DSP through the GTH interface. The interference recognition and spectrum hole detection are completed in the DSP, and the detection result is sent to the FPGA - B processor. It is judged whether the working frequency band needs to be adjusted. According to the judgment result, the working frequency band of the data signal to be adjusted is determined and a frequency band adjustment instruction is generated and sent back to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel.

[0040] According to the signal transmission task requirements, the FPGA - A processor is used for channelization processing and demodulation processing of single - path digital signals, and the processed signals are sent to the FPGA - B processor.

[0041] If the working mode of the current processing control module is the channelization processing mode, the FPGA - B processor is used for merging and modulation processing of digital signals, and the digital signals are output to the DAC and output after being converted into analog signals by the DAC.

[0042] When the number of signal processing channels in the working state is greater than 1, channelization processing output of each path of data is realized according to the working modes of each path of signal processing channels, or frequency bands and bandwidths of each signal processing channel are coordinately controlled.

[0043] The advantages of the present invention compared with the prior art are as follows:

[0044] An adaptive signal receiving system and method provided by the present invention can monitor and identify intentional or unintentional interference signals in a wireless communication environment, and can autonomously and real-time adjust parameters such as frequency, bandwidth, and gain of a receiving channel according to monitoring results, effectively improving the anti-interference ability. At the same time, flexible adjustment of the signal receiving state is realized, and the problems of fixed traditional satellite state and low utilization efficiency are solved. Through signal digital processing, background noise is suppressed and signal-to-noise ratio is improved, effectively enhancing the communication ability of the system. Description of the Drawings

[0045] Figure 1 It is a system design diagram of the adaptive signal receiving method provided by the present invention;

[0046] Figure 2 It is a parallel channelization FPGA processing flow chart provided by the present invention. Detailed Embodiments

[0047] An adaptive signal receiving system and method, through background signal acquisition and processing, autonomously identify interference signals, and then adaptively optimize and adjust parameters such as receiving frequency, bandwidth, and gain of a broadband frequency conversion module to improve the ability to resist intentional or unintentional interference. It can effectively expand the bandwidth of received and processed signals, realize the adaptive adjustment function of wideband input signals required by a flexible payload communication satellite system. Each signal processing channel can perform functions such as channelization processing, demodulation, data merging, modulation, and digital-to-analog conversion on signals. At the same time, actions such as intermediate frequency signal analog-to-digital conversion, spectrum processing, interference identification, frequency band comparison, and generation of commands for adjusting receiving parameters are realized according to the conversion of working modes.

[0048] An adaptive signal receiving system includes a power splitting module, a broadband frequency conversion module, and a processing and control module. The broadband frequency conversion module and the processing and control module form a signal processing channel. The input ends of each signal processing channel are connected to the output end of the power splitting module, where:

[0049] The power splitting module receives an externally input ultra-wideband signal, splits and processes it into N paths of radio frequency signals, and sends them to each signal processing channel;

[0050] The broadband frequency conversion module receives the single-channel RF signal after power division processing by the power division module, and respectively performs low-noise amplification, filtering, gain control, and frequency conversion processing to obtain a single-channel intermediate-frequency signal, which is amplified and output to the processing control module of the signal processing channel where it is located; at the same time, it receives the frequency band adjustment instructions sent back by the processing control modules of the current signal processing channel and the next signal processing channel, adjusts the frequency band of the frequency conversion processing, and then amplifies and outputs the single-channel intermediate-frequency signal to the processing control module of the signal processing channel where it is located.

[0051] The processing control module receives the single-channel intermediate-frequency signal sent by the broadband frequency conversion module, converts it into a digital signal, performs real-time Fourier transform processing on the digital signal, and performs frequency-domain smoothing filtering processing on the signal after Fourier transform processing to obtain a data signal after spectrum processing for realizing the monitoring of the dynamic change of the spectrum. At the same time, it demodulates the digital signal; performs interference identification and spectrum hole detection on the data signal after spectrum processing, judges the working frequency band after obtaining the processing result, and determines the working frequency band of the data signal to be adjusted according to the judgment result; according to the working mode of the current processing control module, combines and processes the demodulated digital signal and the data signal after spectrum processing and outputs them outward, or generates a frequency band adjustment instruction according to the working frequency band of the data signal to be adjusted and sends it back to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel.

[0052] Among them, the working modes of the receiving system include the spectrum detection processing mode and the channelization processing mode, and the working modes of the processing control modules of each signal processing channel are set independently.

[0053] The broadband frequency conversion module includes a low-noise amplifier, a switched filter, a digital controlled attenuator, a tunable local oscillator frequency converter, and an intermediate-frequency amplifier, where:

[0054] The low-noise amplifier performs low-noise amplification processing on the single-channel RF signal according to the noise requirements of the signal processing channel, and sends the signal after low-noise amplification processing to the switched filter.

[0055] The switched filter receives the signal after low-noise amplification processing and adjusts the working frequency band and bandwidth, and sends the adjusted signal to the digital controlled attenuator.

[0056] The digital controlled attenuator receives the adjusted signal and adjusts the signal gain.

[0057] The tunable local oscillator frequency converter performs down-conversion processing on the analog signal after signal gain adjustment delivered by the digital controlled attenuator and sends it to the intermediate-frequency amplifier.

[0058] The intermediate-frequency amplifier receives the signal after down-conversion processing and amplifies and outputs it as a single-channel intermediate-frequency signal.

[0059] The low-noise amplifier, switch filter, digital control attenuator, tunable local oscillator frequency converter, and intermediate frequency amplifier all receive the frequency band adjustment instructions sent back by the processing control module of the current signal processing channel, and adjust the signal adjustment parameters of each part according to the frequency band adjustment instructions.

[0060] The processing control module includes an ADC, FPGA-A, FPGA-B, DAC, and DSP, where:

[0061] The ADC receives the single-channel intermediate frequency signal sent by the broadband frequency conversion module and converts it into a digital signal;

[0062] FPGA-A receives the single-channel digital signal, performs down-conversion processing and then demodulation; performs real-time Fourier transform processing and frequency domain smoothing filtering processing on the single-channel digital signal to obtain the spectrum processed data signal, and sends the spectrum processed data signal to the DSP; performs channelization processing and demodulation on the digital signal and then sends it to FPGA-B;

[0063] The DSP receives the spectrum processed data signal, performs interference identification and spectrum hole detection, judges the working frequency band after obtaining the processing result, and determines the working frequency band of the data signal to be adjusted according to the judgment result;

[0064] FPGA-B receives the spectrum processed data signal and the demodulated signal for combined processing, and at the same time generates a frequency band adjustment instruction according to the working frequency band of the data signal to be adjusted determined by the DSP, and sends it back to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel;

[0065] The DAC receives the combined modulated digital signal, converts it and outputs it.

[0066] FPGA-A includes an FFT, a spectrum processing unit, a channelization processing unit, and a demodulation unit, where:

[0067] The FFT receives the single-channel digital signal sent by the ADC, performs real-time Fourier transform processing, and then sends it to the spectrum processing unit;

[0068] The spectrum processing unit receives the digital signal after real-time Fourier transform processing, performs frequency domain smoothing filtering processing to obtain the spectrum processed data signal;

[0069] The channelization processing unit performs channelization processing on the single-channel digital signal and then sends it to the demodulation unit;

[0070] The demodulation unit demodulates the signal after down-conversion processing and then sends it to FPGA-B.

[0071] FPGA-B includes a frequency band comparison and adjustment unit, a data merging unit, and a modulation unit, where:

[0072] The frequency band comparison and adjustment unit receives the working frequency band of the data signal output by the DSP, determines the working frequency band of the data signal to be adjusted by the DSP, generates a frequency band adjustment instruction and sends it back to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel;

[0073] The data merging unit receives the data signal after spectrum processing and the demodulated signal, performs merging processing and then sends it to the modulation unit;

[0074] The modulation unit receives the digital signal after merging processing and sends it to the DAC.

[0075] After the broadband frequency conversion modules of each signal processing channel perform self-adjustment according to the frequency band adjustment instruction sent by the processing control module of the signal processing channel where they are located, the frequency band and bandwidth of each signal processing channel are coordinated and controlled through the frequency band adjustment instruction sent by the processing control module of other signal processing channels.

[0076] FPGA-A, FPGA-B, and DSP are all externally equipped with DDR3 memories. Two DDR3 memories are externally equipped for each FPGA-A and FPGA-B to achieve data caching and format conversion; two DDR3 memories are externally equipped for each DSP to achieve data transmission after spectrum processing, and each DDR3 memory uses a GTH interface to achieve data transmission.

[0077] The adaptive adjustment signal receiving method includes the following steps:

[0078] The ultra-wideband input signal is received and divided into N single-channel RF signals, and the signal level is processed by the LNA and then sent to the broadband frequency conversion module;

[0079] The working frequency band and bandwidth of each single-channel RF signal are selected and switched through a switched filter, the signal gain is adjusted by a digital controlled attenuator, the frequency conversion processing is realized by a tunable local oscillator frequency converter, and the intermediate frequency signal is amplified by an intermediate frequency amplifier and output to the processing control module;

[0080] The analog signal is converted into a digital signal through the ADC, input to FPGA-A to complete real-time fast Fourier transform processing and digital signal frequency domain smoothing filtering processing, and the dynamic change of the spectrum is monitored through digital signal time-frequency analysis to obtain the monitoring result;

[0081] If the working mode of the current processing control module is the spectrum monitoring processing mode, the data after spectrum processing is transmitted to the DSP through the GTH interface. The interference recognition and spectrum hole detection are completed in the DSP, and the detection result is sent to the FPGA-B processor. It is judged whether the working frequency band needs to be adjusted, and the working frequency band of the data signal to be adjusted is determined according to the judgment result, and a frequency band adjustment instruction is generated and sent back to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel;

[0082] According to the requirements of signal transmission tasks, the FPGA-A processor is used to perform channelization processing and demodulation processing on single-channel digital signals, and the processed signals are sent to the FPGA-B processor;

[0083] If the working mode of the current processing control module is the channelization processing mode, the FPGA-B processor is used to perform digital signal merging and modulation processing, output digital signals to the DAC, and output according to the conversion of the DAC into analog signals.

[0084] When the number of signal processing channels in the working state is greater than 1, according to the working modes of each signal processing channel, channelization processing output of each path of data or coordinated control of the frequency bands and bandwidths of each signal processing channel is realized.

[0085] The following is further described in conjunction with the accompanying drawings of the specification and preferred embodiments:

[0086] In the current embodiment, as Figure 1 shown, the adaptive adjustment method for receiving signals is an adaptive signal reception adjustment processing system based on spectrum sensing, including a power splitting module, a broadband frequency conversion module, and a processing control module. The power splitting module is used to receive ultra-wideband signals and split the signals into multiple paths; the broadband frequency conversion module is used to realize signal filtering, frequency conversion, and signal amplification; the processing control module is the core part of the embodiment of the present invention, used to realize intermediate frequency signal analog-to-digital conversion, spectrum processing, interference identification, frequency band comparison, generating instructions for adjusting reception parameters, and can also perform functions such as channelization processing, demodulation, data merging, modulation, and digital-to-analog conversion on signals.

[0087] (1) The power splitting module is used to receive ultra-wideband signals and split the signals into multiple paths. To ensure the stability and non-reflection of the input signal, a waveguide isolator (such as a Ka-band GB1706(P) type isolator) can be set at the input port; to realize the transfer of the signal from the waveguide to the coaxial cable, a waveguide-to-coaxial converter with an E-plane probe coupling method can be used; to realize parallel processing of multiple signals and increase the working bandwidth, (multiple groups of) one-to-two microstrip Wilkinson power splitters can be used in parallel, and A493 ceramic substrate microstrip lines can be adopted.

[0088] (2) The broadband frequency conversion module is used to realize signal filtering, frequency conversion, and signal amplification. It consists of a low-noise amplifier (LNA, such as an NC10229C-2640 chip), a switched filter (such as a WND0403H chip), a digital control attenuator (such as an NC13114C-140PD chip), an adjustable local oscillator frequency converter (the mixer can use an NC17104C-620 chip), an intermediate frequency amplifier (such as a Gain Block amplifier NC11224C-103 chip), etc.

[0089] The single-channel radio frequency signal after passing through the power splitting module (such asFigure 1 For the RF1 shown, first, the level that can meet the requirements of the link noise figure is achieved through a low-noise amplifier, then the selection and switching of the operating frequency band and bandwidth are realized through a switched filter, the gain adjustment is completed by a digital control attenuator, and then the operating frequency is down-converted to the intermediate frequency by a tunable local oscillator frequency converter. Finally, the intermediate-frequency signal is amplified and output. Among them, the relevant adjustment methods of the switched filter, digital control attenuator, and tunable local oscillator frequency converter can adopt a TTL control circuit interface.

[0090] (3) The processing and control module is used to implement functions such as analog-to-digital conversion, spectrum processing, interference recognition, frequency band comparison, and generation of instructions for adjusting receiving parameters of the intermediate-frequency signal. At the same time, it can also perform functions such as channelization processing, demodulation, data merging, modulation, and digital-to-analog conversion on the signal.

[0091] The processing and control module consists of a high-speed analog-to-digital converter (ADC, such as the ADC-AD 12DJ3200 chip), a high-performance programmable logic gate array processor (FPGA, such as the Xilinx V7-690T chip), a high-performance data processor (DSP, such as the 8-core DSP6678 chip), and a high-speed digital-to-analog converter (DAC, such as the DAC-GDA12SL3GMCCRH chip). To meet the requirements of caching, format packing, etc. during the data processing process, the FPGA and DPS are externally equipped with DDR3 memory (such as the W3J512M32GT-1333B2I chip).

[0092] The single-channel intermediate-frequency signal (such as Figure 1 IF1 shown) after wideband frequency conversion first completes the conversion from analog signal to digital signal through a high-speed ADC; then the digital signal is input to the high-performance FPGA-A to complete digital down-conversion processing, and the fast Fourier transform (FFT) and frequency-domain smoothing filtering processing of the signal are completed through digital signal time-frequency analysis technology to realize the monitoring function of the dynamic change of the spectrum. The data after spectrum processing is transmitted to the high-performance DSP through the GTH interface to complete interference recognition and spectrum hole detection, and the processing results are sent to the next high-performance FPGA-B processor through the Rapid IO interface or EMIF interface. In the FPGA-B processor, the frequency interval between the background interference signal and the working signal is compared to determine whether the relevant frequency band can be used. If the operating frequency band needs to be adjusted, relevant instructions for controlling the wideband frequency conversion module to adjust parameters such as receiving frequency, bandwidth, and gain are generated and the adjustment instructions are sent through the TTL interface.

[0093] The digital signal after ADC completes processing such as parallel channelized data sampling, screening, and demodulation in FPGA-A, further suppressing background noise and improving the signal-to-noise ratio, and then transmitting the processed signal to FPGA-B. The parallel channelized processing is used to solve the problem of large input signal bandwidth. First, the input signal after AC is sampled at high speed and divided into channels (such as n channels), and then parallel down-conversion processing is performed to zero-frequency signals, and then integral comb filtering (CIC) and passband filtering are respectively performed to suppress out-of-band signals, and then up-conversion is performed to restore to the frequency before sampling. The specific situation is as Figure 2 shown. Among them, the CIC processing mixes the time-domain signal x n with the local oscillator signal L n to shift the spectrum of the signal to be processed to zero frequency. Since the CIC filtering processing results in poor in-band flatness and long transition band, a half-band (HB) filter component is added.

[0094] FPGA-B realizes the data splicing of the channelized processing through spectrum splicing technology, or realizes the merging of the channelized data and the downlink data after spectrum processing. The spectrum splicing technology processes the overlapping part data of adjacent sub-band signals in a smooth fitting manner. When splicing, two spectra are generated respectively, and by fusing and averaging the results of the two spectra, a spliced spectrum is finally obtained to reconstruct the original broadband signal and improve the accuracy of spectrum monitoring. Suppose the spectrum range to be monitored is [F s , F e . The spectrum is intercepted, and the first intercepted spectrum is subjected to FFT calculation to obtain the discrete Fourier transform F1. The range of the first spectrum is Similarly, the i-th intercepted spectrum is subjected to FFT calculation to obtain the discrete Fourier transform F i , and the range of the first spectrum is Extract the overlapping segment of the (i + 1)-th spectrum and the corresponding data segment H i and perform Fourier transform to obtain Extract the overlapping segment of the (i - 1)-th spectrum and the corresponding data segment Q i and perform Fourier transform to obtain Furthermore, solve the spectrum splicing fitting parameters for the spectrum data and . The spectrum splicing fitting parameters {a i , b i} satisfy the following conditions:

[0095]

[0096] Using the fitting parameters obtained from the above formula, calculate F i = F i-1 + ai F i +b i This method realizes the spectrum smoothing of the front and rear segments by obtaining a fit using the overlapping spectrum data samples of the front and rear segments.

[0097] After the channelization processing is completed in FPGA-B, the data after data and spectrum processing are merged, modulated, etc.; the modulated data is output after being converted by DAC. It should be emphasized that the data after spectrum processing and the data after channelization processing can be selectively transmitted separately or merged according to the task requirements through instructions.

[0098] To cooperate with the FPGA to efficiently process data, 2 pieces of DDR3 are externally attached to each FPGA for data caching and format packaging, etc. To cooperate with the DSP to efficiently detect, 2 pieces of DDR3 are externally attached to each DSP. To achieve the high-speed transmission of the data after spectrum processing, an internal Rapid IO (GTH) interface is adopted.

[0099] (4) For multiple signals working simultaneously, the control broadband frequency conversion module adjustment instructions generated after single-channel spectrum processing can be sent to each broadband frequency conversion module respectively to achieve the cooperative adjustment function. When working in multiple channels, each channel can be selected to work in the spectrum monitoring and processing mode or the channelization processing mode respectively. For example, Figure 1 in the shown case, it can be instructed to set the first channel to work only in the spectrum monitoring and processing mode, and uniformly adjust the broadband frequency conversion modules of the first and second channels to avoid intentional or unintentional interference; set the second channel to work only in the channelization processing mode to complete signal transceiver. When working in multiple channels, it can also be selected that each channel works in different bandwidths.

[0100] (5) As Figure 1 shown, a method for adaptively adjusting the received signal includes the following steps:

[0101] 1) The ultra-wideband input signal is received by the power splitter module and split into multiple signals;

[0102] 2) The single-channel radio frequency signal after power splitting reaches the required level through the LNA;

[0103] 3) The working frequency band and bandwidth are selected and switched through the switched filter;

[0104] 4) The gain adjustment is completed by the digital control attenuator;

[0105] 5) The radio frequency signal is down-converted to the intermediate frequency by the tunable local oscillator frequency converter;

[0106] 6) The intermediate frequency signal is amplified by the intermediate frequency amplifier and output to the processing control module;

[0107] 7) The intermediate frequency signal completes the conversion from the analog signal to the digital signal through the high-speed ADC;

[0108] 8) The digital signal is input to the high-performance FPGA-A to complete real-time fast Fourier transform (FFT)

[0109] processing;

[0110] 9) In the FPGA-A, digital signal frequency-domain smoothing filtering processing is completed, and the monitoring function of the dynamic change of the spectrum is realized through digital signal time-frequency analysis technology.

[0111] 10) The data after spectrum processing is transmitted to the high-performance DSP through the GTH interface, and interference recognition and spectrum hole detection are completed in the DSP;

[0112] 11) The processing result of the DSP is sent to the high-performance FPGA-B processor, and the frequency interval between the background interference signal and the working signal is compared to determine whether the relevant frequency band can be used. If the working frequency band needs to be adjusted, relevant instructions for controlling the broadband frequency conversion module to adjust parameters such as the receiving frequency, bandwidth, and gain are generated;

[0113] 12) The relevant adjustment instructions are sent to the broadband frequency conversion module through the TTL interface for corresponding adjustments, that is, steps 3) to 5) are repeated to complete interference monitoring and avoidance; it should be emphasized that for the case of multiple signals working simultaneously, the control broadband frequency conversion module adjustment instructions generated after single-channel spectrum processing can be sent to each broadband frequency conversion module respectively to achieve the coordinated linkage adjustment function;

[0114] 13) The data after spectrum processing by FPGA-A is selected whether to be input to FPGA-B according to the task requirements;

[0115] 14) On the other hand, the digital signal processed by the ADC completes data processing such as channelized data sampling, screening, and demodulation in the FPGA-A;

[0116] 15) The processed channelized data is transmitted to the FPGA-B;

[0117] 16) In the FPGA-B, the data after channelization processing and the data after spectrum processing are merged, modulated, etc.; it should be emphasized that the data after spectrum processing and the data after channelization processing can be selectively transmitted separately or merged according to the task requirements;

[0118] 17) The modulated data is output after DAC conversion;

[0119] 18) When operating in multiple channels, each channel can be selected to work in the spectrum monitoring and processing mode or the channelization processing mode respectively. For example, if it is set that the first channel only works in the spectrum monitoring and processing mode, then the first channel executes steps 2) to 12), and then the relevant parameters of the broadband frequency conversion modules of the first and second channels can be adjusted uniformly; if the spectrum monitoring data needs to be downloaded for analysis, the steps 13, 16), and 17) can be selected and executed by instruction.

[0120] 19) When operating in multiple channels, each channel can be selected to work in the spectrum monitoring and processing mode or the channelization processing mode respectively. If it is set that the second channel only works in the channelization processing mode to complete signal transceiver, then the second channel executes steps 2) to 7), does not execute steps 8) to 13), and directly executes steps 13) to 17).

[0121] 20) When operating in multiple channels, it is also possible to select each channel to work at different bandwidths. For example, for a Ka-band ultra-wideband input signal with a bandwidth of 3 GHz, 3-channel parallel processing can be set, and the working bandwidth of each channel is 1 GHz.

[0122] In this embodiment, by receiving cooperative signals and through identification and processing, the relevant parameters can be adaptively optimized and adjusted to improve the signal-to-noise ratio of communication and ensure the communication quality. Further, the comprehensive application of multiple groups (taking 2 groups as an example) of channels can effectively expand the bandwidth of the received and processed signals and realize the adaptive adjustment function of the wideband input signal required by the flexible payload communication satellite system.

[0123] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change, and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention all belong to the protection scope of the technical solutions of the present invention.

[0124] The content not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

1. An adaptive signal receiving system, characterized in that: It includes a power splitting module, a broadband frequency conversion module, and a processing and control module. The broadband frequency conversion module and the processing and control module form a signal processing channel, and the input end of each signal processing channel is connected to the output end of the power splitting module, where: The power splitting module receives the externally input ultra-wideband signal, performs power splitting processing into N RF signals and sends them to each signal processing channel; The broadband frequency conversion module receives the single-channel RF signal after the power splitting processing of the power splitting module, respectively performs low-noise amplification, filtering, gain control, and frequency conversion processing to obtain a single-channel intermediate-frequency signal, amplifies it and outputs it to the processing and control module of the signal processing channel where it is located; at the same time, it receives the frequency band adjustment instructions sent back by the processing and control modules of the current signal processing channel and the next signal processing channel, adjusts the frequency band of the frequency conversion processing, and then amplifies and outputs the single-channel intermediate-frequency signal to the processing and control module of the signal processing channel where it is located; The processing and control module receives the single-channel intermediate-frequency signal sent by the broadband frequency conversion module, converts it into a digital signal, performs real-time Fourier transform processing on the digital signal, performs frequency-domain smoothing filtering processing on the signal after the Fourier transform processing to obtain a spectrum-processed data signal for realizing the monitoring of the dynamic change of the spectrum, and at the same time demodulates the digital signal; performs interference recognition and spectrum hole detection on the spectrum-processed data signal, determines the working frequency band of the data signal to be adjusted according to the obtained processing result after judging the working frequency band, and according to the working mode of the current processing and control module, combines and processes the demodulated digital signal and the spectrum-processed data signal and outputs them externally or generates a frequency band adjustment instruction according to the working frequency band of the data signal to be adjusted and sends it back to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel; Among them, the working modes of the receiving system include a spectrum detection processing mode and a channelization processing mode, and the working modes of the processing and control modules of each signal processing channel are set independently.

2. An adaptive signal receiving system according to claim 1, characterized in that: The broadband frequency conversion module includes a low-noise amplifier, a switch filter, a digital control attenuator, an adjustable local oscillator frequency converter, and an intermediate-frequency amplifier, where: The low-noise amplifier performs low-noise amplification processing on the single-channel RF signal according to the noise requirements of the signal processing channel, and sends the signal after the low-noise amplification processing to the switch filter; The switch filter receives the signal after the low-noise amplification processing, regulates the working frequency band and bandwidth, and sends the regulated signal to the digital control attenuator; The digital control attenuator receives the regulated signal and adjusts the signal gain; The adjustable local oscillator frequency converter performs down-conversion processing on the analog signal after the signal gain adjustment delivered by the digital control attenuator and sends it to the intermediate-frequency amplifier; The intermediate-frequency amplifier receives the signal after the down-conversion processing, amplifies and outputs it as a single-channel intermediate-frequency signal.

3. An adaptive signal receiving system according to claim 2, characterized in that: The low-noise amplifier, switch filter, digital-controlled attenuator, tunable local oscillator frequency converter, and intermediate-frequency amplifier all receive the frequency band adjustment instructions sent back by the processing control module of the current signal processing channel, and adjust the signal adjustment parameters of each part according to the frequency band adjustment instructions.

4. The adaptive signal receiving system according to claim 2, wherein: The processing control module includes an ADC, an FPGA-A, an FPGA-B, a DAC, and a DSP, wherein: The ADC receives the single-channel intermediate-frequency signal sent by the broadband frequency conversion module and converts it into a digital signal; The FPGA-A receives the single-channel digital signal, performs down-conversion processing and then demodulation; performs real-time Fourier transform processing and frequency-domain smoothing filtering processing on the single-channel digital signal to obtain the spectrum-processed data signal, and sends the spectrum-processed data signal to the DSP; performs channelization processing and demodulation on the digital signal and then sends it to the FPGA-B; The DSP receives the spectrum-processed data signal, performs interference recognition and spectrum hole detection, judges the working frequency band after obtaining the processing result, and determines the working frequency band of the data signal to be adjusted according to the judgment result; The FPGA-B receives the spectrum-processed data signal and the demodulated signal for combined processing, and at the same time generates a frequency band adjustment instruction according to the working frequency band of the data signal to be adjusted determined by the DSP, and sends it back to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel; The DAC receives the combined modulated digital signal, converts it and outputs it.

5. The adaptive signal receiving system according to claim 4, wherein: The FPGA-A includes an FFT, a spectrum processing unit, a channelization processing unit, and a demodulation unit, wherein: The FFT receives the single-channel digital signal sent by the ADC, performs real-time Fourier transform processing, and then sends it to the spectrum processing unit; The spectrum processing unit receives the digital signal after real-time Fourier transform processing, and performs frequency-domain smoothing filtering processing to obtain the spectrum-processed data signal; The channelization processing unit performs channelization processing on the single-channel digital signal and then sends it to the demodulation unit; The demodulation unit demodulates the signal after down-conversion processing and then sends it to the FPGA-B.

6. The adaptive signal receiving system according to claim 5, wherein: The FPGA-B includes a frequency band comparison and adjustment unit, a data combination unit, and a modulation unit, wherein: The frequency band comparison and adjustment unit receives the working frequency band of the data signal output by the DSP, determines the working frequency band of the data signal to be adjusted determined by the DSP, generates a frequency band adjustment instruction, and sends it back to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel; The data combination unit receives the spectrum-processed data signal and the demodulated signal, performs combined processing, and then sends it to the modulation unit; The modulation unit receives the combined processed digital signal and sends it to the DAC.

7. The adaptive signal receiving system according to claim 6, wherein: After the broadband frequency conversion module of each signal processing channel realizes self-regulation according to the frequency band adjustment instruction sent by the processing control module of the signal processing channel where it is located, the frequency band and bandwidth of each signal processing channel are jointly controlled through the frequency band adjustment instruction sent by the processing control module of other signal processing channels.

8. The adaptive adjustment signal receiving system according to claim 6, wherein: External DDR3 memories are provided for FPGA-A, FPGA-B, and DSP respectively. Two DDR3 memories are externally connected to each of FPGA-A and FPGA-B to realize data caching and format conversion; two DDR3 memories are externally connected to each DSP to realize data transmission after spectrum processing. Each DDR3 memory uses a GTH interface to realize data transmission.

9. An adaptive adjustment signal receiving method implemented according to the receiving system described in claim 8, characterized in that Including: The received ultra-wideband input signal is power-divided into N single-channel RF signals, and after the signal level is processed by the LNA, it is sent to the broadband frequency conversion module; The working frequency band and bandwidth of each single-channel RF signal are selected and switched through a switch filter, the signal gain is adjusted by a digital control attenuator, frequency conversion processing is realized by a tunable local oscillator frequency converter, and the intermediate frequency signal is amplified by an intermediate frequency amplifier and output to the processing control module; The analog signal is converted into a digital signal through the ADC, input to FPGA-A to complete real-time fast Fourier transform processing and digital signal frequency domain smoothing filtering processing, and the dynamic change of the spectrum is monitored through digital signal time-frequency analysis to obtain the monitoring result; If the working mode of the current processing control module is the spectrum monitoring processing mode, the data after spectrum processing is transmitted to the DSP through the GTH interface. Interference recognition and spectrum hole detection are completed in the DSP, and the detection result is sent to the FPGA-B processor to judge whether the working frequency band needs to be adjusted. According to the judgment result, the working frequency band of the data signal to be adjusted is determined, and a frequency band adjustment instruction is generated and sent back to the broadband frequency conversion modules of the current signal processing channel and the next signal processing channel; According to the signal transmission task requirements, the FPGA-A processor is used to perform channelization processing and demodulation processing on single-channel digital signals, and the processed signals are sent to the FPGA-B processor; If the working mode of the current processing control module is the channelization processing mode, the FPGA-B processor is used to perform digital signal merging and modulation processing, and the digital signal is output to the DAC and output after being converted into an analog signal by the DAC.

10. The adaptive adjustment signal receiving method according to claim 9, wherein: When the number of signal processing channels in the working state is greater than 1, channelization processing output of each path of data or frequency band and bandwidth collaborative control of each signal processing channel is realized according to the working modes of each signal processing channel.

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