中文摘要：

针对非周期短码扩频长码加扰直扩（NPLSC-DSSS）信号的伪码估计问题,该文首先给出了m序列三阶相关函数（TCF）共同峰理论和NPLSC-DSSS信号TCF估计量的概率函数。其次,利用TCF峰的共轭系特性构建了TCF峰值序列,提出了TCF共同峰检测的二元假设模型和利用拟合优度检验的TCF共同峰精检测算法。同时,为提高伪码估计性能,该文利用正反向TCF三阶相关峰性质和共轭系TCF峰值点累加和递增性质排除大量伪峰。最后通过矩阵斜消法实现长短伪码的盲估计。仿真结果表明,该文方法在低信噪比条件下能够有效估计NPLSC-DSSS信号的伪随机码。

英文摘要：

For blind estimation of Pseudo-random Noise（PN） codes in Non-Periodic Long and Short Codes Direct Sequence Spread Spectrum（NPLSC-DSSS） signals, the Triple Correlation Function（TCF） common peak theory of m-sequence and probability function of NPLSC-DSSS signals＇ TCF estimate are given firstly. Then sequences of TCF peaks are built with their conjugate sets＇ features, binary hypothesis test model and accurate detection algorithm of TCF common peaks using goodness of fit test are proposed. Meanwhile, many false peaks are eliminated to improve the estimation performance using the property of forward and backward TCF peaks and cumulative-sum＇s increasing trend of TCF peaks in conjugate sets. Lastly, the primitive polynomials of long and short pseudo-random codes can be estimated with the matrix＇s oblique elementary method. Simulations show that the proposed method can effectively estimate the PN codes of NPLSC-DSSS signal at low Signal-to-Noise Ratio（SNR）.