ZC-OFDM信号的分集特性与应用研究

分布式网络化电子信息系统的发射信号需要满足较强分集特性的要求,相同长度、不同根值的ZC序列之间的分集特性由其根值本身及其根值差值决定。通过ZC序列与ZC-OFDM信号的采样序列之间的同构性,对ZC-OFDM信号的分集特性进行了研究,结合ZC-OFDM信号的分集特性以及分布式网络化电子信息系统的特点,提出了最优有效采样长度计算算法,该算法解决了在分布式网络系统布站数一定以及发射信号带宽有限、时宽有限的情况下,如何确定发射信号的有效采样长度使得各个发射站信号的分集特性能够达到最强的问题。结合常规探测信号的时宽、带宽取值范围和最优有效采样长度计算算法,对波形的参数进行了设计,对其在分布式网络化电子信息系统的信号处理效果进行了仿真。仿真结果表明,不同根值的ZCOFDM信号具有良好的分集特性,能够使得分布式网络化电子信息系统在回波接收处理时对各个发射站发射信号的回波信号进行有效的分离。

Research on Diversity Characteristics and Application of ZC Sequence Code Modulated OFDM Signal Waveform

The transmitted signal of a distributed networked system needs to meet the requirements of strong diversity characteristics. The diversity characteristics between ZC sequences of the same length and different root values are determined by the root value itself and its root value difference. In this paper, the diversity characteristics of ZC OFDM signals are studied by the isomorphism between the ZC sequence and the sampling sequence of ZC OFDM signals. Combining the diversity characteristics of ZC OFDM signals and the characteristics of distributed networked systems, an optimal effective sampling length calculation algorithm is proposed. The algorithm is used to solve how the effective sampling length of the transmitted signal is determined so that the diversity characteristics of them can reach the strongest when the number of distributed network systems is limited as well as the bandwidth and time width of the transmitted signal. Combined with the time width, bandwidth range and optimal effective sampling length calculation algorithm of conventional detection signals, the parameters of the waveform are designed, and the signal processing effect of the distributed network system is simulated. The simulation results show that the ZC OFDM signals with different root values are characterized by enabling the distributed networked system to effectively separate the echo signals of the signals transmitted by each transmitting station during the echo receiving process.