An anti-pulse interference method based on an MPPSK modulation mode

Abstract

The invention discloses an anti-pulse interference method based on an MPPSK modulation mode. The method comprises the following steps: firstly, carrying out median filtering processing on a pulse interference signal at a receiving end; carrying out amplitude limiting on the residual interference by using the wave eliminator so as to further weaken interference, further filtering residual pulse interference by adopting a self-adaptive filtering technology, then carrying out coherent low-pass processing, namely multiplying the signal subjected to self-adaptive filtering by a coherent carrier wave, carrying out low-pass filtering, and finally carrying out SVM (Support Vector Machine) judgment in combination with a corresponding bit synchronization algorithm. Compared with a traditional demodulation method, the method has the advantages that the bit synchronization requirement is greatly reduced, the pulse interference is greatly eliminated, the demodulation performance is improved, the wireless communication quality in a complex electromagnetic confrontation environment can be greatly improved, meanwhile, the signal processing is easy to realize, the requirement on hardware can be greatly reduced, and resources are saved.

Description

technical field [0001] The invention belongs to the field of information demodulation in communication systems, relates to a digital communication anti-jamming demodulation technology, in particular to an anti-pulse jamming demodulation method based on a multiple position phase shift keying (MPPSK) modulation mode. Background technique [0002] 1. MPPSK modulation [0003] Spectrum is a non-renewable resource that carries various growing wireless services and is precious to all countries in the world. How to use limited spectrum resources more efficiently is crucial to the sustainable development of my country's modernization. M-ary Position Phase Shift Keying (MPPSK: M-ary Position Phase Shift Keying) is a digital phase modulation that distinguishes different symbols by modulating the information of different symbols at different time positions of the carrier, and can achieve spectral efficiency and power efficiency The free conversion of , has high flexibility, and has gr...

AI Technical Summary

Problems solved by technology

[0009] 1) Anti-pulse interference generally adopts limiting measures, which use the difference between the amplitude of pulse interference and the useful signal in the time domain, and use the limiting characteristics of the limiter to weaken the amplitude of the interference pulse. This limiting method has developed into a "wide -limit-narrow" anti-interference system, the system uses a broadband amplifier to amplify the pulse interference before the limiter without broadening the pulse interference, and cascades a narrow-band filter after the limiter to further suppress the pulse interference from the frequency domain. However, the limiting method itself cannot overcome the contradiction of suppressing pulse interference and reducing the harmful effects of nonlinear beat frequency, which is not conducive to the subsequent narrow-band filter to suppress zero-band interference. At the same time, only by using the characteristics of the limiter to weaken the amplitude of pulse interference As long as the threshold is low, although pulse interference can be suppressed to a limited extent, the useful signal loss in the processed received signal is large, which is not conducive to demodulation judgment

[0010] 2) The pulse interference extinguishing method is based on the difference in amplitude between the pulse interference and the useful signal, and uses the switching characteristics of the gate circuit to suppress the pulse interference. During the duration of the extinguishing pulse, the output of the extinguisher is zero, and the signal is transmitted without distortion and attenuation in the rest of the time , this method can overcome the harmful effect of nonlinear beat frequency that cannot be overcome by the clipping method itself. However, in order to effectively suppress the pulse interference, the extinguishing time must be greater than the duration of the pulse interference at the extinguishing gate, and its size is determined by the The bandwidth of the band-pass filter and the shape of the corresponding curve, while the instantaneous response of the filter of the IF amplifier of the general communication receiver is not good, the amount of pulse interference being broadened is many times larger than the reciprocal of the bandwidth of the half-power point, and the performance is unstable

[0011] 3) The pulse interference cancellation method uses the characteristic that the pulse interference is higher than the useful signal amplitude, first detects the pulse interference, and then subtracts or adds the original interference with the original interference to eliminate the pulse interference. The implementation complexity of this method is high, and Due to the randomness of pulse interference, this method is not applicable and has high requirements for communication receivers

Images