Radar Communication Integrated Waveform Design And Research

With the development of information technology,modern combat platform needs to be loaded with equipments with different functions,including communication,radar,and electronic interference.The concentration of a variety of electronic equipment on a combat platform has brought problems such as electromagnetic compatibility,hardware equipment redundancy,and spectrum resource shortage.In order to improve resource utilization and platform combat effectiveness,the integration of electronic equipment has become necessary.In this context,the radar-communications integration has become one of the mainstream development directions of future combat systems.The use of integrated radar communication waveforms is the main means to realize the integrated radar communication system,and the design and selection of the waveforms have a vital impact on the performance of the entire system and signal processing methods.Therefore,it is of great significance to carry out integrated waveform design research.This paper analyzes the differences between radar and communication systems and the feasibility of integration from the perspectives of functions,bands and hardware structure,and introduces the ambiguity function,bit error rate and peak-to-average power ratio(PAPR)for evaluating the performance of integrated waveforms.Several typical integrated waveform design schemes are analyzed in detail,and the principle,characteristics and generation methods of waveform are discussed.In order to reduce the influence of modulation data on target detection,spread spectrum technology is used for integrated waveform design,and a single carrier design scheme based on spread spectrum is proposed.This scheme uses a chaotic sequence as a spread spectrum sequence,which has lower range ambiguity function sidelobe,higher range resolution,lower bit error rate and strong anti-interference performance.At the same time,aiming at the problem that the traditional window function can not effectively suppress the sidelobe of integrated waveform,a design method of sidelobe suppression filter based on convex optimization theory is proposed.The simulation results show that this method is suitable for the sidelobe suppression of integrated waveform,and the main sidelobe ratio is more than 44 db.Aiming at the problem of low communication rate of the integrated waveform based on single carrier,a multi-carrier-based integrated waveform design scheme is proposed,which improves the communication rate and has good radar detection performance.First,the principle of multi-carrier phase coded(MCPC)integrated signal is studied in detail,the waveform ambiguity function is derived,and the ambiguity function,communication rate and bit error rate performance are analyzed.Secondly,in order to improve the sensitivity of MCPC signals to Doppler,the orthogonal chirp signals are used in the waveform design,and an integrated waveform based on orthogonal chirp division multiplexing(OCDM)is proposed.The ambiguity function is derived,and the radar and communication performance are simulated and analyzed.The results show that the signal has lower sidelobe and bit error rate than the MCPC.Then,the PAPR of the signal is suppressed by the iterative clipping algorithm.Finally,a radar processing algorithm based on the modulation symbol domain is studied.The algorithm eliminates the influence of modulation information and uses the discrete Fourier transform to obtain target information.Simulation shows that this method effectively eliminates the influence of modulation information.Compared with matched filtering processing,the window function can be used for sidelobe suppression.