Design And Performance Analysis Of Radar Communication Integration System Based On Chaotic Waveform

As two mainstream technologies in electronic information industry,radar and communication are widely used in both military and civilian fields.Due to the different working mode,they are usually implemented on different hardware platforms and the signal waveform is also very different.For radar detection waveform,most of the required signals are regular known signals.It requires excellent autocorrelation characteristics and large signal bandwidth.However,the waveform of wireless communication signal is random and uncertain,which requires high spectral efficiency.Due to equipment size,load and low interception requirements,in intelligent transportation,electronic reconnaissance and other applications,radar and communication independent hardware platform will no longer be suitable.In fact,radar and wireless communication have similar system architecture,including antenna,transmitter,receiver,signal processor and so on.Therefore,it is considered to integrate the two to meet the needs of miniaturization of electronic equipment.In the integrated radar communication system,waveform design that meets both functions of radar and communication is the key to the integrated system design.Common integrated signal waveform include binary phase-shift keying linear frequency modulation signal（BPSK-LFM）,M code in two-phase coding and Frank code in polyphase coding.With the application of 5G communication,spectrum resources become increasingly scarce and frequency band overlap occurs between the two technologies.How to improve spectrum utilization is an urgent problem to be solved.Chaotic signal has the advantages of anti-interference,anti-multipath and natural concealability due to its characteristic of wide spectrum,easy generation and aperiodic and can be realized by low cost and low power consumption analog circuits.It is easy to be applied to the design and integration of actual systems and has an important influence on many fields such as meteorology,biology and control engineering.In this paper,an integrated waveform design based on solvable chaos is proposed and the radar detection and communication decoding algorithm using the waveform is studied.The following work is carried out:（1）The feasibility of waveform sharing design for radar and communication is discussed.In view of the design of shared waveform,the generation method and waveform characteristics of chaotic waveform are introduced.According to its characteristics,an integrated structure of radar communication based on chaotic waveform is proposed.（2）The fuzzy function of three common integrated waveform and chaotic waveform is studied.The fuzzy function graph is compared and analyzed and the chaotic signal has better range-velocity resolution.Therefore,it is feasible to apply it in radar communication integration.The corresponding radar ranging and velocity measurement algorithms are proposed,including target distance detection based on correlation method and target radial velocity detection based on velocity MUSIC.By comparing and analyzing the ranging and velocity measurement results of different signal waveforms in the case of single target and multi-target,when the bit-signal-to-noise ratio of the receiver is 0,the ranging performance in the case of single target is improved by 10%compared with that of LFM signal and in the case of multi-target is improved by 20%.It is concluded that the chaotic signal used in this paper can obtain better radar performance in the case of single target and multi-target.（3）The communication decoding algorithm based on chaos matching filter is studied,the bit error rate of different decoding thresholds is analyzed theoretically and the performance of communication bit error rate of different signal waveform is verified by simulation.Through the comparative analysis of communication performance between chaotic signal and common integrated signal,including spectrum occupancy analysis and bit error rate analysis.when BER=10^-1,the E_b/N₀ of chaotic signal is lower than BPSK-LFM signal 1dB,but 1.4dB higher than Frank code.However,through spectrum occupancy analysis,it can be seen that Frank code gains higher bit error rate at the expense of spectrum,so chaotic signal adopted in this paper will achieve better communication performance under the condition of the same spectrum occupancy.The simulation and analysis results show that the solvable chaotic waveform can meet the comprehensive requirements of radar and communication and can be used as an alternative waveform for future integrated system design.