Research And Implementation Of Shortwave Wideband Signal Detection And Extraction Algorithm

Due to the continuous improvement of communication demand,the short-wave communication environment becomes extremely crowded.The electromagnetic environment is complex and changeable.The signal form is various,and can arrive at the same time.In non-cooperative communication,the primary task is to detect subband signals in wide-band channels,measure their related parameters and extract the signals.The key technologies of detecting and extracting non-cooperative signals are studied,and the system implementation of the relevant algorithms is completed on the host computer in this paper.In shortwave wide-band signal detection and extraction,DDC(Digital Down Conversion)channelized high computational complexity.The performance of subband signal detection based on white Gaussian noise is poor under the complex characteristics of shortwave channel.To solve the above problems,a wide-band signal detection extraction method based on efficient structure analysis-synthesis nonuniform channelization and wideband spectrum detection is proposed in this paper.the correctness of this method is verified by the simulation analysis,comparative analysis the complexity of two kinds of channel structure.Aiming at the reconstruction error of the reconstructed filter banks in the analysissynthesis non-uniform channelization,a prototype Finite Impulse Response(FIR)filter with a two-channel lattice structure is first designed,and then,a better stopband attenuation is obtained by double optimization,and finally,a reconstructed filter that meets the reconstruction conditions is obtained by eliminating the distortion caused by mirror image components through non-zero interpolation.A 16-channel 256-order reconstruction filter bank is designed in this paper.Simulation analysis shows that the reconstruction filter bank with a lattice structure can meet the reconstruction requirements.Aiming at the influence of noise floor interference and multi-spectral peak signal on Wide-band signal detection in short-wave channel,a signal detection algorithm based on morphology is proposed,and the simulation shows that the algorithm can smooth the noise floor and signal spectrum peak well.The approximate constant false alarm detection can be achieved under different undulation noise base and different SNR(signal-to-noise ratio),and the detection probability is higher under low SNR.On the basis of the above research,a wide-band signal detection system is built,and the basic functions of 4M bandwidth shortwave signal detection and extraction are realized.