【作者】 张翼；

【导师】 曹建蜀；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2018， 硕士

【摘要】 随着电子信息技术的发展,作战平台的电磁环境日益复杂,为了应对战场上瞬息万变的作战形势,如何提高自身的生存能力和作战能力将变得尤为重要。因此,如何将雷达设备和通信设备整合到一起,利用有限的频谱资源和空间同时实现目标探测和数据通信将是未来研究的重点方向。本文在信号能量共享的基础上,通过将正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术与多相码和混沌序列相结合来设计一体化波形,并对波形进行了后续处理。所作的主要工作和创新如下:1)对巴克码、frank码、P4码的自相关特性、模糊函数及多普勒敏感特性进行了对比分析,仿真结果表明P4码具有优良的自相关特性、较好的抗多普勒敏感特性,且利用P4码的互补特性可以构成P4循环互补码,因此本文将通信信息融入P4码的移位中再进行OFDM调制作为一体化波形。2)对Logistic与Chebyshev混沌模型的特性作出了分析,综合对比其初值敏感性、自相关性能,最后采取二者的混合映射方式作为混沌序列的生成模型,构建了一种基于分组OFDM的DCSK一体化波形。3)针对OFDM信号峰均功率比过高的问题,对传统的直接限幅法、部分传输序列法降低峰均功率比技术作出了仿真分析。针对部分传输序列法时间复杂度过高的问题,结合粒子群算法与遗传算法的优良特性,提出了一种PSO-GA算法来对部分传输序列法的相位因子选取进行优化,仿真结果表明,该算法在损失少量峰均比性能的情况下降低了时间复杂度。4)为了获得更好的峰均比性能,本文在部分传输序列法的基础上提出了MDPSO-Clipping算法,该算法首先在离散粒子群算法对相位因子的选取方式上进行改进,然后再与直接限幅法相结合。仿真结果表明,该算法在降低了系统时间复杂度的同时能够获得比部分传输序列法更好的峰均比性能。5)针对本文所设计的一体化信号,对其波形参数的选取进行了分析并给出了雷达通信一体化系统的工作模式。然后对接收端的信号处理算法进行了研究,最后对两种波形的通信性能作出了分析。更多还原

【Abstract】 With the development of electronic information technology,the electromagnetic environment of combat platform has become increasingly complex.In order to cope with the rapidly changing combat situation on the battlefield,how to improve its survivability and combat capability will become particularly important.Therefore,how to integrate radar equipment and communication equipment together to achieve target detection and data communication using limited spectrum resources and space will be the focus of future research.Based on the signal energy sharing,this paper designs an integrated waveform by combining Orthogonal Frequency Division Multiplexing(OFDM)technology with polyphase code and chaotic sequence,and performs subsequent processing on the waveform.The main work and innovations made are as follows:1)The autocorrelation characteristics,ambiguity functions and Doppler sensitivity characteristics of Barker code,frank code and P4 code are compared and analyzed.Simulation results show that P4 code has excellent autocorrelation characteristics and better Doppler sensitivity characteristics.The complementary features of P4 codes can be used to construct P4 cyclic complementary code.Therefore,this paper integrates the communication information into the cyclic shift of P4 code and then performs OFDM modulation as an integrated waveform.2)The characteristics of Logistic and Chebyshev chaotic models are analyzed.And their initial sensitivity and autocorrelation performance are comprehensively compared.Finally,taking the hybrid mapping of them as a chaotic sequence generation model,a DCSK integrated waveform based on packet OFDM is constructed.3)For the problem that the peak-to-average power ratio of the OFDM signal is too high,a simulation analysis is performed on the conventional direct limiting method and partial transmission sequence method to reduce the peak-to-average power ratio.Aiming at the problem that the time complexity of partial transmission sequence method is too high,combined with the excellent characteristics of particle swarm optimization and genetic algorithm,a PSO-GA algorithm is proposed to optimize the phase factor selection of partial transmission sequence method.The simulation results show that the algorithm reduces the time complexity with a small loss ofpeak-to-average ratio performance.4)In order to obtain better peak-to-average ratio performance,this paper proposes the MDPSO-Clipping algorithm based on partial transmission sequence method.The algorithm firstly improves the selection method of the phase factor in the discrete particle swarm algorithm,and then combines it with the direct limiting method.The simulation results show that the proposed algorithm can obtain better peak-to-average performance than the partial transmission sequence method while reducing the system time complexity.5)For the integrated signal designed in this paper,the selection of its waveform parameters is analyzed and the working mode of the radar communication integrated system is given.Then the signal processing algorithm of the receiver is studied.Finally,the communication performance of the two waveforms is analyzed.更多还原