【作者】 张恒；

【导师】 张文旭；

【作者基本信息】 哈尔滨工程大学 ， 信息与通信工程， 2021， 硕士

【摘要】 随着电子信息技术的进步与发展,雷达与通信设备在各个领域都有着广泛应用,在某些应用场景下,不仅需要目标探测还需要数据传输。为满足这些需求,仅仅把两种相互独立工作的设备简单堆叠会导致系统冗余和复杂度增加,因此解决该问题的有效方法是将雷达和通信波形共用,也就是利用同一波形在完成雷达功能的同时又可以实现通信功能。在军用领域,此方法可减小作战设备体积和电磁干扰,提高硬件利用率且简化系统设计,具有重要研究意义和实用价值。本文在雷达与通信共用波形基础上,通过正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术与相位编码相结合去设计一体化波形,主要研究成果如下:本文将当前雷达通信一体化波形设计研究进行了汇总,将其分成一体化共用和一体化复用两种。研究了一体化共用波形的设计要素和评价指标,对其中单载波体制一体化共用波形设计原理,从时域、频域和模糊函数角度进行仿真分析。在OFDM技术基本原理的基础上,研究了多载波体制雷达通信共用波形设计方法,其实质为脉冲化的OFDM通信波形,并给出其信号模型。针对OFDM信号具有峰均功率比过高的问题,对限幅技术和部分传输序列技术进行了研究,仿真结果表明两种技术都可有效较低信号的峰均功率比。在多载波传输场景下,由于基于OFDM的一体化波形模糊函数会受到传输信息时变性的影响,因此,从一体化波形的通信调制信息出发,通过仿真分析对比了二进制相位编码Baker码、多相Frank码和P4码的自相关特性和模糊函数,其中,P4码具有优秀的自相关特性,而且可以通过循环移位方式获得互补P4码。通过对不同调制方式的一体化波形仿真比较,基于OFDM的互补P4码一体化波形具有优秀的雷达探测性能。针对循环前缀使模糊函数产生“伪峰”,降低能量利用率,影响雷达性能的问题,本文提出利用空白保护间隔的方法,在不影响通信质量的前提下消除虚假目标,并且有效降低雷达模糊函数的PSLR。根据本文设计的基于互补P4码一体化信号,提出适合其工作的一体化系统,并对系统的波形参数、运行模式、处理框架进行了详细介绍。围绕基于互补P4码一体化波形,在系统接收端可以通过脉冲压缩级联FFT方法有效分辨出被探测目标,最后对不同调制方式的一体化波形通信性能做出了对比分析。更多还原

【Abstract】 With the progress and development of electronic information technology,radar and communication equipment are widely used in various fields.In some application scenarios,not only target detection but also data transmission is required.To meet these needs,simply stacking two devices that work independently of each other will lead to increased system redundancy and complexity.Therefore,an effective way to solve this problem is to share the radar and communication waveforms,that is,to use the integrated radar communication waveform in the It also completes the communication function while completing the radar function.In the military field,this method can reduce the volume of combat equipment and electromagnetic interference,improve hardware utilization and simplify system design,and has important research significance and practical value.This paper uses Orthogonal Frequency Division Multiplexing(OFDM)technology and phase-encoded signals to design integrated waveforms based on the shared waveforms of radar and communications.The main research work and results are as follows:This article summarizes the current research on integrated waveform design of radar communication,and divides it into two types: integrated sharing and integrated multiplexing.The design elements and evaluation indicators of the integrated shared waveform are studied,and the design principle of the integrated shared waveform of the single carrier system is simulated and analyzed from the perspective of time domain,frequency domain and ambiguity function.Based on the basic principles of OFDM technology,the design method of multicarrier radar communication common waveform is studied,which is essentially pulsed OFDM communication waveform,and its signal model is given.Aiming at the problem that OFDM signal has too high peak-to-average power ratio,the limiting technology and partial transmission sequence technology are studied,and the simulation results show that both technologies can effectively lower the peak-to-average power ratio of the signal.In the multicarrier transmission scenario,because the OFDM-based integrated waveform ambiguity function will be affected by the time variation of the transmission information,starting from the communication modulation information of the integrated waveform,the binary phase encoding Baker code and the multiphase are compared through simulation analysis.The autocorrelation characteristics and ambiguity functions of Frank codes and P4 codes.Among them,P4 codes have excellent autocorrelation characteristics,and complementary P4 codes can be obtained by cyclic shifting.Through the simulation and comparison of the integrated waveform of different modulation methods,the OFDM-based complementary P4 code integrated waveform has excellent radar detection performance.Aiming at the problem that the cyclic prefix causes the ambiguity function to produce "false peaks",which reduces the energy utilization rate and affects the performance of the radar,this paper proposes a method of using blank guard intervals to eliminate false targets without affecting the communication quality,and effectively reduce the radar ambiguity function PSLR.According to the integrated signal based on complementary P4 code designed in this paper,an integrated system suitable for its work is proposed,and the waveform parameters,operating mode and processing framework of the system are introduced in detail.Focusing on the integrated waveform based on the complementary P4 code,the detected target can be effectively distinguished by the pulse compression cascaded FFT method at the receiving end of the system.Finally,a comparative analysis of the integrated waveform communication performance of different modulation methods is made.更多还原