A broadband receiving device against blocking interference

Abstract

The present invention provides a broadband receiving device for anti-blocking interference, which includes a band-pass filter, a demodulator, a low-pass filter, a digital-to-analog converter, a filtering limiter, and a digital up-conversion group connected in sequence; the band-pass filter group and the demodulator group are used to shift the broadband signal onto the baseband signal respectively; the low-pass filter and the digital-to-analog converter are used to convert the baseband signal into a digital baseband signal; the filtering limiter is used to filter and limit the digital baseband signal so that the power spectrum of the baseband signal conforms to the power spectrum distribution characteristics of the useful signal; the digital up-conversion group is used to shift the baseband signal to the digital intermediate frequency point. The beneficial effects of the present invention: A broadband receiving device for anti-blocking interference adopts frequency band division reception and then the method of digital combining. Through frequency domain division, the influence range of strong in-band interference signals is isolated. So that the system can also work under the condition of strong interference.

Description

Technical Field

[0001] The present invention belongs to the field of communication technologies, and particularly relates to a broadband receiving device for anti-blocking interference. Background Art

[0002] Blocking interference means that when a strong interference signal and a useful signal are simultaneously input into a receiver, the strong interference will saturate the devices on the receiver link and cause nonlinear distortion. For current broadband communication systems, such as direct spread spectrum communication (DS), orthogonal frequency division multiplexing (OFDM), and code division multiple access (CDMA), when the in-band interference signal is small, the interference can be eliminated through correlation reception or forward error correction coding, etc., so that the useful signal can be transmitted. However, if the amplitude of the in-band interference signal is very large and the analog-to-digital converter (ADC) overflows severely, even if there is enough useful signal, the system cannot demodulate it. Summary of the Invention

[0003] In view of this, the present invention aims to provide a broadband receiving device for anti-blocking interference, and proposes a method of receiving through frequency band division and then combining in the digital domain. Through frequency domain division, the influence range of strong in-band interference signals is isolated; then the signals are received separately and combined in the digital domain, and the combined signal follows the previous broadband receiving digital processing link without major modification to the original system. It has the advantages of strong anti-interference ability and good compatibility with various broadband communication protocols.

[0004] To achieve the above object, the technical solution of the present invention is realized as follows:

[0005] A broadband receiving device for anti-blocking interference includes a band-pass filter, a demodulator, a low-pass filter, an analog-to-digital converter, a filter limiter, and a digital up-conversion group connected in sequence.

[0006] The band-pass filter group and the demodulator group are used to shift the broadband signal to the baseband signal respectively.

[0007] The low-pass filter and the analog-to-digital converter are used to convert the baseband signal into a digital baseband signal.

[0008] The filter limiter is used to filter and limit the digital baseband signal so that the power spectrum of the baseband signal conforms to the power spectrum distribution characteristics of the useful signal.

[0009] The digital up-conversion group is used to shift the baseband signal to the digital intermediate frequency point.

[0010] Furthermore, the broadband receiving device is provided with multiple paths of band-pass filters, demodulators, low-pass filters, analog-to-digital converters, filter limiters, and digital up-conversion groups connected in sequence.

[0011] Further, there is also a digital intermediate frequency combiner. The digital intermediate frequency signals generated by a multi-path of sequentially connected band-pass filters, demodulators, low-pass filters, digital-to-analog converters, filter limiters, and digital up-conversion groups are combined through the same digital intermediate frequency combiner, and finally the whole process of frequency domain segmentation and combination is completed.

[0012] Further, the band-pass filter is used to divide the broadband signal into N paths of radio frequency or intermediate frequency signals.

[0013] Further, it also includes a phase-locked loop PLL. The phase-locked loop PLL outputs N local oscillators. When the frequency range of the broadband signal is f0 - f1, the frequency points of the N local oscillator signals are:

[0014]

[0015] Further, the demodulator is a quadrature demodulator, which is used to demodulate the intermediate frequency or radio frequency signal output by the band-pass filter into an IQ baseband signal.

[0016] Further, the IQ baseband signal is converted into a digital baseband signal through a low-pass filter and an analog-to-digital converter ADC, and is sent to an FPGA or DSP for digital domain processing.

[0017] Further, the digital domain IQ baseband signal is input to the filter limiter.

[0018] Further, the IQ signal after limiter processing is input to the digital up-converter module. Digital up-conversion of N frequency points is realized through a complex multiplier, and the digital baseband signal is converted into a digital intermediate frequency signal.

[0019] Compared with the prior art, the broadband receiving device for anti-blocking interference of the present invention has the following beneficial effects:

[0020] (1) The broadband receiving device for anti-blocking interference of the present invention adopts frequency band division reception, and then the method of digital combination. Through frequency domain segmentation, the influence range of strong in-band interference signals is isolated, so that the system can work under strong interference conditions.

[0021] (2) The broadband receiving device for anti-blocking interference of the present invention combines the data after split-path reception processing in the digital domain. The combined signal can follow the previous broadband receiving digital processing link, and does not require major modifications to the original system. It has the advantages of strong anti-interference ability and good compatibility with various broadband communication protocols.

[0022] (3) The broadband receiving device for anti-blocking interference of the present invention can be applied to broadband communication systems such as direct spread spectrum sequence DS, orthogonal frequency division multiplexing OFDM, and code division multiple access CDMA, and can also be applied to other broadband communication systems. Description of the Drawings

[0023] The accompanying drawings, which form a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0024] Figure 1 It is a schematic diagram of the system block diagram of the anti-blocking interference broadband receiving device according to the embodiment of the present invention;

[0025] Figure 2 It is a schematic diagram of the principle of frequency domain division combination according to the embodiment of the present invention;

[0026] Figure 3 It is a schematic diagram of the principle block diagram of the filter limiter according to the embodiment of the present invention. Detailed implementation manners

[0027] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0028] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0029] As Figures 1 to 3 shown, the present solution proposes an anti-blocking interference broadband receiving device. Through frequency band division reception and then digital combining method, through frequency domain division, the influence range of strong in-band interference signals is isolated; then the signals are received in branches and combined in the digital domain, and the combined signals follow the previous broadband receiving digital processing link, without the need for major modification to the original system. It has the advantages of strong anti-interference ability and good compatibility with various broadband communication protocols.

[0030] 1. Move the broadband signal to N baseband signals respectively through a bandpass filter bank and a demodulator bank;

[0031] 2. Convert the baseband signal into a digital baseband signal through N independent baseband low-pass filters and analog-to-digital converters ADCs;

[0032] 3. Filter and limit the digital baseband signal to make the power spectrum of the baseband signal conform to the power spectrum distribution characteristics of the useful signal;

[0033] 4. Move the N baseband signals to N digital intermediate frequency points through a digital upconversion bank.

[0034] 5. Realize the combination of the digital intermediate frequency signals through a simple adder to complete the whole process of frequency domain division and combination. Please refer to Figure 1 , which is the system block diagram of an anti-blocking interference broadband receiving device of the present invention. It can be applied to broadband communication systems such as direct spread spectrum sequence DS, orthogonal frequency division multiplexing OFDM, and code division multiple access CDMA, and can also be applied to other broadband communication systems..

[0035] As Figure 1 shown: Its typical structure consists of a phase-locked loop (PLL), N band-pass filters, a demodulator, a low-pass filter, an analog-to-digital converter, a filtering limiter, and a digital intermediate-frequency combiner.

[0036] Among them, the N band-pass filters divide the broadband signal into N radio-frequency or intermediate-frequency signals, as Figure 2 a Figure 2 shown in c.

[0037] The PLL outputs N local oscillators. When the frequency range of the broadband signal is f0 to f1, the frequency points of the N local oscillator signals are: as Figure 2 shown in b

[0038]

[0039] The N quadrature demodulators demodulate the intermediate-frequency or radio-frequency signals output by the band-pass filters into IQ baseband signals.

[0040] The IQ baseband signals pass through a low-pass filter and an analog-to-digital converter (ADC), are converted into digital baseband signals, and are sent to an FPGA or DSP for digital-domain processing.

[0041] The IQ baseband signals in the digital domain are input to the filtering limiter, as Figure 3 shown. First, they enter an FIR filter to filter the frequency-domain signals in the overlapping parts between frequency bands and compensate for the amplitude and phase losses of the analog filter. Then, the signals are transformed into the frequency domain through a fast Fourier transform (FFT) module, the power spectral distribution characteristics are calculated through a power spectrum extraction module, and compared and analyzed with the power spectrum specified by the protocol. Then, the power spectrum of the excess part is attenuated through a frequency-domain limiter module. Finally, the signals are restored to the time domain through an inverse Fourier transform (IFFT) module.

[0042] The IQ signals after limiter processing are input to the digital up-converter module, and digital up-conversion at N frequency points is achieved through complex multipliers to convert the digital baseband signals into digital intermediate-frequency signals.

[0043] Finally, the digital intermediate-frequency signals of each frequency band are input to the digital intermediate-frequency combining module, and the intermediate-frequency signals are combined through simple addition operations to be converted into broadband digital intermediate-frequency signals, as Figure 2 shown in d.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention, and they should all be covered by the scope of the claims and the specification of the present invention.

[0045] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A broadband receiving device against blocking interference, characterized in that: It includes a band-pass filter, a demodulator, a low-pass filter, a digital-to-analog converter, a filtering limiter, and a digital up-conversion group connected in sequence; The band-pass filter group and the demodulator group are used to shift the broadband signal to the baseband signal respectively; The low-pass filter and the digital-to-analog converter are used to convert the baseband signal into a digital baseband signal; The filtering limiter is used to filter and limit the digital baseband signal so that the power spectrum of the baseband signal conforms to the power spectrum distribution characteristics of the useful signal; The digital up-conversion group is used to shift the baseband signal to the digital intermediate frequency point; Inside the broadband receiving device, there are multiple band-pass filters, demodulators, low-pass filters, digital-to-analog converters, filtering limiters, and digital up-conversion groups connected in sequence; There is also a digital intermediate frequency combiner. The digital intermediate frequency signals generated by the multiple band-pass filters, demodulators, low-pass filters, digital-to-analog converters, filtering limiters, and digital up-conversion groups connected in sequence are combined through the same digital intermediate frequency combiner, and finally the whole process of frequency domain segmentation and combination is completed; The broadband receiving device for anti-blocking interference performs frequency domain segmentation and then receives and combines in the digital domain; The demodulator is a quadrature demodulator, which is used to demodulate the intermediate frequency or radio frequency signal output by the band-pass filter into an IQ baseband signal; The IQ baseband signal is converted into a digital baseband signal through a low-pass filter and an analog-to-digital converter ADC and sent to an FPGA or DSP for digital domain processing; The IQ baseband signal in the digital domain is input to the filtering limiter. The IQ baseband signal in the digital domain is input to the filtering limiter. First, it enters the FIR filter to filter the frequency domain signal in the overlapping part between frequency bands and compensate for the amplitude and phase loss of the analog filter. Then, the signal is transformed to the frequency domain through the fast Fourier transform FFT module, the power spectrum distribution characteristics are calculated through the power spectrum extraction module and compared with the power spectrum specified by the protocol. Then, the power spectrum of the excess part is attenuated through the frequency domain limiter module, and finally the signal is restored to the time domain through the inverse Fourier transform IFFT module.

2. The broadband receiving device for anti-blocking interference according to claim 1, wherein: The band-pass filter is used to divide the broadband signal into N paths of radio frequency or intermediate frequency signals.

3. The broadband receiving device for anti-blocking interference according to claim 1, wherein: It also includes a phase-locked loop PLL. The PLL outputs N local oscillators. When the frequency range of the broadband signal is f0 - f1, the frequency points of the N local oscillator signals are:

4. The broadband receiving device for anti-blocking interference according to claim 1, characterized in that: The limited IQ signal is input to the digital up-converter module, and the digital up-conversion of N frequency points is realized through a complex multiplier to convert the digital baseband signal into a digital intermediate frequency signal.

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