摘要
研究扩频通信技术中信号优化问题,信道的干扰影响直接序列扩频信号(DSSS)传输的正确性,给直扩信号参数检测与估计带来了困难,需要一种有效的算法来增强抗干扰能力。为了解决上述问题,利用变化域的FFT重叠变换干扰抑制提供一种最有效的方法,可通过对DSSS信号加窗处理和重叠变换,使信号频谱泄露大为降低,而且使信号的损失也大为减小,使误码率可以降到很低。另外提出一种FFT重叠变换干扰抑制算法和信号功率谱二次处理的联合估计窄带干扰环境下DSSS信号的伪码(PN)周期并进行仿真。仿真结果表明,算法在较低的输入信噪比和低信干比条件下能准确地估计DSSS信号PN码周期,证明了FFT重叠变换干扰抑制算法的有效性。
The optimization for signals in sread spectrum communications is discussed in the paper. Channel interference affects the correctness of direct sequence spread spectrum （DSSS） signals transmission, which makes it difficult to detect and estimate the parameters of DSSS signals. So an effective algorithm is needed to enhance its anti - interference. To solve the problem, the lapped FFT based on transform domain provided a most effective interference suppression algorithm. Windowed processing and lapped transform for DSSS signals can greatly reduce signals spectrum leakage and loss of signals, and low error rate is obtained. In addition, a lapped FFT algorithm and reprocessing of the power spectrum density algorithm were proposed to detect and estimate the PN sequence＇s period of the DSSS signal. Theoretical analysis and simulation results show that the proposed algorithm can quickly estimate the PN sequence＇s period of DSSS signal in the low SNR and low SIR environment, which also proves the efficience of the lapped FFT algorithm.
出处
《计算机仿真》
CSCD
北大核心
2012年第2期109-115,共7页
Computer Simulation
基金
国家自然科学基金项目(61071196)
国家自然科学基金-中物院NSAF联合基金项目(10776040)
教育部新世纪优秀人才支持计划(NCET-10-0927)
信号与信息处理重庆市市级重点实验室建设项目(CSTC
2009CA2003)
重庆市自然科学基金项目(CSTC
2009BB2287
CSTC
2010BB2398
CSTC
2010BB2411)
关键词
傅里叶变换
重叠变换干扰抑制
直接序列扩频信号
伪码周期
功率谱
FFT
Overlap narrow - band interference suppression
Direct sequence spread spectrum （DSSS）
Periodic of PN sequence
Power spectrum density
