多径软扩频信号伪码周期盲估计

发布时间：2018-12-18 00:24

【摘要】：针对多径信道下因多径衰落造成软扩频信号伪码周期难以估计的问题,提出了一种基于二次功率谱的多径软扩频信号伪码周期盲估计方法。首先,将一般的单径软扩频信号扩展到多径模型;然后,在多径软扩频信号模型的基础上计算信号的一次功率谱;其次,将求出的一次功率谱作为输入信号计算信号的二次功率谱,理论分析表明信号的二次功率谱在伪码周期整数倍处将会出现峰值谱线;最后,通过检测峰值谱线间的间距就可以实现多径软扩频信号的伪码周期估计。通过仿真实验表明,在伪码周期估计正确率为100%、伪码序列长度为127位和255位时,所提方法比时域相关法提高信噪比约1 d B和2 d B;在同一对比条件下,所需要的平均累加次数均少于时域相关法。实验结果表明,所提方法对伪码周期进行估计,在减少计算量的同时,还提高了估计的正确率。
[Abstract]:In order to solve the problem that the pseudo code period of soft spread spectrum signals is difficult to estimate due to multipath fading in multipath channels, a blind pseudo code period estimation method for soft spread spectrum signals based on secondary power spectrum is proposed. Firstly, the general single path soft spread spectrum signal is extended to the multipath model, then the primary power spectrum of the signal is calculated on the basis of the multipath soft spread spectrum signal model. Secondly, the obtained primary power spectrum is used as the quadratic power spectrum of the input signal to calculate the signal. The theoretical analysis shows that the peak power spectrum of the signal will appear at the integer times of the pseudo-code period. Finally, the pseudo code period estimation of multipath soft spread spectrum signals can be realized by detecting the spacing between peak spectral lines. The simulation results show that the proposed method can improve the SNR of 1 dB and 2 dB compared with the time domain correlation method when the accuracy rate of pseudo code period estimation is 100 bits and the length of pseudo code sequence is 127 bits and 255 bits. Under the same contrast condition, the average accumulative times required are less than the time domain correlation method. The experimental results show that the proposed method not only reduces the computational complexity but also improves the accuracy of the estimation.
【作者单位】：重庆邮电大学信号与信息处理重庆市重点实验室;
【基金】：国家自然科学基金资助项目(61671095,61371164) 信号与信息处理重庆市市级重点实验室建设项目(CSTC2009CA2003) 重庆市教育委员会科研项目(KJ130524,KJ1600427,KJ1600429)~~
【分类号】：TN914.42

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