Design Of Low-intercept Baseband Mixed Signal And Low Complexity Receiver Algorithm

In the course of military confrontation,the enemy's counterparts can measure?identify and locate military communications signals,so it's vital for military communications to design signals with low interception characteristics and achieve efficient transmission of information.The mixed signals in communications are usually caused by frequency division multiplexing,interference,etc.,but mixed signals can be designed and used artificially for communication security and protection in turn.We propose to study the design the low-intercept baseband mixed signals(single-carrier/multi-carrier),which can effectively improve the concealment and anti-interception of communication signal waveforms.At the same time,the processing performance and complexity of the receiving end also determine the performance of the system.This paper also studies the low-complexity detection algorithm and the performance enhancement detection algorithm at the receiving end of the partner.It can provide a new technical route for the construction of our military's new communications system.First,this paper introduces the specific design scheme of single-carrier baseband mixed signal and multi-carrier baseband mixed signal,and analyzes the necessary conditions for the separation of mixed signals and the fundamental factors of affecting the separation performance of mixed signals.Based on the Gibbs algorithm's successful application experience in MIMO detection and SCMA detection,this paper applies Gibbs algorithm to the baseband mixed signal detection at the receiver of this paper.The basic principle of Gibbs sampling algorithm is introduced.The preprocessing flow of mixed signal and the separation algorithm of symbol-by-symbol pair in the case of single carrier and multi-carrier are deduced in detail.The mixed signal separation performance is combined to find the optimal design parameters of the mixed signal and the design parameters of the separation algorithm.On this basis,the low-complexity techniques such as Max-Log and QRD-M and the performance enhancement techniques such as Bias and soft output are used in this paper to make the receiving end of the partner receive the optimal performance and complexity.In this paper,the Gibbs algorithm combined with QRD-M technology is deduced in detail.The simulation results show that Gibbs algorithm combined with QRD-M technology can effectively reduce the complexity especially in the case of high-order modulation.Bias technology can effectively solve the problem that the symbol pair group falls into the local optimum at high signal-to-noise ratio.The separation performance of the single-carrier baseband mixed signal and the multi-carrier baseband mixed signal is obviously improved after using the Bias technique.Extracting the soft information in the Gibbs algorithm,combined with the codec technology,compared with the hard decision output model,the soft decision output model can have about 2dB performance gain.Finally,this paper evaluates the low interceptivity of the baseband mixed signal from the perspective of the modulation characteristics of the hidden signal,the angle of the anti-conventional blind source separation algorithm,and the performance loss caused by the non-cooperative parameter estimation error.The simulation results show that when the Non-cooperative have 10% Channel estimation error and 0.1T sampling point deviation,there is about 1(25)2 of dB and 2(25)3dB decrease in performance.Baseband mixed signals carry valid information in two ways,and the spectral efficiency has not dropped.Based on the above analysis,this paper analyzes and summarizes the good concealment and low interceptivity of single-carrier baseband mixed signal and multi-carrier baseband mixed signal proposed in this paper.