基于单载波频域均衡的直接序列扩频自适应抗干扰技术

Adaptive anti-jamming technologies based on direct sequence spread spectrum and single carrier frequency domain equalization

针对复杂多径信道环境下直接序列扩频系统性能受限问题,提出了一种单载波频域均衡(SCFDE)与直接序列扩频(DSSS)技术有机结合的自适应抗干扰扩频通信体制,其特点是通过频域均衡克服多径带来的频率选择性衰落,同时支持自适应调整扩频因子实现系统传输速率与抗干扰能力的重构。进一步地,结合SCFDE频域均衡的特点,充分利用其接收端固有的快速傅里叶(FFT)变换过程实现对干扰强度、干扰类型等信息的伴随式检测与分析,在线优化选取频域承载点,提升系统对干扰,特别是阻塞式干扰的适应性。仿真结果表明,无论是高斯还是多径信道环境下,所提的基于SCFDE的直扩波形都具有良好的通信性能,且部分频带陷波对通信性能影响较小,验证了自适应优选信息频域承载点抗干扰的有效性。

To solve the performance limitation of direct sequence spread spectrum system in complex multipath envi-ronment,an adaptive anti-jamming spread spectrum framework that organically combines single carrier frequency do-main equalization(SCFDE)and direct sequence spread spectrum(DSSS)technologies was proposed.The frequency multipath fading was overcame by frequency domain equalization,and the transmission rates and high reliability was re-configured by deploying variable spread factors.Moreover,the inherent fast Fourier transform process was made full use at the receiver to realize the adjoint detection and analysis of interference intensity,interference type and other informa-tion,etc.Then,the frequency domain bearing point online was optimized and selected to improve the adaptability to the interference,especially blocking interference.The simulation results show that the proposed direct spread spectrum waveform based on SCFDE has good communication performance in both Gaussian and multipath environments,and the notch of some frequency bands has little impact on the communication performance,which verifies the effectiveness of anti-jamming by adaptive optimizing information frequency domain bearers.