LFM-MPSK雷达通信一体化系统时频联合同步技术研究

相比于传统的单一的雷达或通信设备,雷达通信一体化系统具有易集成、小型化、高谱效等优势,其中基于线性调频的一体化信号的系统方案应用广泛。在一体化系统通信功能实现方案中,传统的同步技术会降低通信速率。针对这一问题,设计了一种包含两类线性调频载波的一体化信号,并利用线性调频良好的自相关特性,提出了一种基于Costas环的时间和载波频率联合同步技术。在该技术中,首先设计了基于线性调频的Costas环结构,实现对两类调频载波的跟踪,然后根据两类载波的频率信息反演出通信时延和载波频偏。仿真结果表明,该同步技术在不影响通信效率及雷达性能的情况下,可实现一体化信号的时频联合同步,且误码率与传统同步技术的性能相当。 

Joint Timing and Frequency Synchronization in LFM-MPSK based Radar and Communication Integrated System

Compared with traditional radar or communication devices, the integrated radar and communication system is easy to be integrated and smaller with higher spectrum efficiency, in which the linear frequency modulation (LFM) based integrated system is widely used. In term of realizing the communication function, the traditional synchronization scheme will reduce the data rate. Thus, an integrated signal consisting of two LFM carriers is designed. Then, a Costas loop-based joint time and carrier frequency synchronization is proposed by using the good autocorrelation of LFM. The proposed synchronization method contains two steps. First, a LFM based Costas loop is designed to track two LFM carriers. Second, the delay and carrier frequency offset are retrieved from the frequency of these two carriers. Simulation results show that the proposed technique can realize the joint time-frequency synchronization without affecting the communication efficiency and radar performance, and the bit error rate is comparable to that of traditional synchronization technique.