摘要
针对基带扩频信号的频谱范围较宽,信号在带限的信道中传输时需要对信号进行带宽限制,从而造成码间干扰和频谱泄露的问题,将基带扩频信号通过脉冲成形器处理后对其主要参数的抗截获性能进行了研究,并使用两次功率谱的方法对该类信号的伪码周期进行了估计。理论分析证明,做两次功率谱以后的信号以脉冲串的周期来扩展谱线,且信号主要能量将会聚集在一些类似于基带成形脉冲二次谱形状的尖锐脉冲处,通过测量这些尖锐脉冲间的间距即可估计出基带扩频信号的伪码周期。仿真结果证明,两次功率谱的方法可以在低信噪比的条件下实现对带脉冲成形基带扩频信号伪码周期的估计,且该算法对伪码周期估计的正确率比文献[1]算法约提高7dB左右。
The spectrum of the baseband spread spectrum signal has a wide frequency range,when the signal is transmitted in the band limited channel,the bandwidth of the signal needs to be limited,thereby causing intersymbol interference.Therefore,in order to reduce the inter-symbol crosstalk between baseband spread spectrum signals and their occupied bandwidth,this paper studied the main parameters of its low interception performance of the baseband spread spectrum signal after it passed through the pulse shaper,and it estimated pseudocode period by using twice power spectrum.The theoretical analysis proved that the signal after twice power spectrum extends spectral line on the period of impulse sequence,and the main energy of the signal would gather in some sharpness similar to that of the quadratic spectrum of the baseband shaping pulse.The pseudo-code period of the baseband spread spectrum signal could be estimated by measuring the spacing between these sharp pulses.Simulation results show that the method of twice power spectrum can be used to estimate the pseudo-code period of pulse shaped spread baseband signal under low signal-to-noise ratio condition.And accuracy of the algorithm to estimate the proposed pseudo-code period improves approximately 7 dB compared to the method without pulse shaping.
作者
李群
张天骐
袁帅
Li Qun;Zhang Tianqi;Yuan Shuai(Chongqing Key Laboratory of Signal & Information Processing,ChongqingUniversity of Posts & Telecommunications,Chongqing 400065,China)
出处
《计算机应用研究》
CSCD
北大核心
2019年第8期2483-2487,2491,共6页
Application Research of Computers
基金
国家自然科学基金资助项目(61671095,61371164,61702065,61701067,61771085)
信号与信息处理重庆市市级重点实验室建设项目(CSTC2009CA2003)
重庆市研究生科研创新项目(CYS17219)
重庆市教育委员会科研项目(KJ1600427,KJ1600429)
关键词
扩频信号
脉冲成形
二次功率谱
伪码周期
盲估计
spread spectrum signal
pulse shaping
power spectrum reprocessing
PNsequence period
blind estimation
