To estimate the spreading sequence of the direct sequence spread spectrum (DSSS) signal, a fast algorithm based on maximum likelihood function is proposed, and the theoretical derivation of the algorithm is provided. ...To estimate the spreading sequence of the direct sequence spread spectrum (DSSS) signal, a fast algorithm based on maximum likelihood function is proposed, and the theoretical derivation of the algorithm is provided. By simplifying the objective function of maximum likelihood estimation, the algorithm can realize sequence synchronization and sequence estimation via adaptive iteration and sliding window. Since it avoids the correlation matrix computation, the algorithm significantly reduces the storage requirement and the computation complexity. Simulations show that it is a fast convergent algorithm, and can perform well in low signal to noise ratio (SNR).展开更多
研究了m序列三阶相关函数特性,证明了不同周期m序列三阶相关函数存在共同峰,推导得到共同峰的特性以及共同峰坐标与m序列本原多项式之间对应关系,基于上述理论提出了非合作通信下的非周期长码直扩信号伪随机码估计方法。加性高斯白噪声...研究了m序列三阶相关函数特性,证明了不同周期m序列三阶相关函数存在共同峰,推导得到共同峰的特性以及共同峰坐标与m序列本原多项式之间对应关系,基于上述理论提出了非合作通信下的非周期长码直扩信号伪随机码估计方法。加性高斯白噪声下的仿真结果表明,本方法仅需1/4倍长码周期长度信号和4 d B信噪比,估计非周期长码直扩信号的扩频码和长扰码的正确概率就可达到99%以上。展开更多
基金supported by Joint Foundation of and China Academy of Engineering Physical (10676006)
文摘To estimate the spreading sequence of the direct sequence spread spectrum (DSSS) signal, a fast algorithm based on maximum likelihood function is proposed, and the theoretical derivation of the algorithm is provided. By simplifying the objective function of maximum likelihood estimation, the algorithm can realize sequence synchronization and sequence estimation via adaptive iteration and sliding window. Since it avoids the correlation matrix computation, the algorithm significantly reduces the storage requirement and the computation complexity. Simulations show that it is a fast convergent algorithm, and can perform well in low signal to noise ratio (SNR).
文摘研究了m序列三阶相关函数特性,证明了不同周期m序列三阶相关函数存在共同峰,推导得到共同峰的特性以及共同峰坐标与m序列本原多项式之间对应关系,基于上述理论提出了非合作通信下的非周期长码直扩信号伪随机码估计方法。加性高斯白噪声下的仿真结果表明,本方法仅需1/4倍长码周期长度信号和4 d B信噪比,估计非周期长码直扩信号的扩频码和长扰码的正确概率就可达到99%以上。
