An Improved Adaptive Tracking Algorithm based on Iteration and Discriminator Optimization for Burst DSSS Signals

摘要

To enhance the pseudo-range measurement performance based on code synchronization of burst Direct Sequence Spread Spectrum (DSSS) signals, a new adaptive tracking algorithm based on iteration is proposed. After a forward tracking based on initial values provided by acquisition or coarse tracking, a backward estimation is adopted to get more precise initial values. Based on these precise initial values, forward tracking is carried out again. By performing forward tracking and backward estimation iteratively, a more and more precise tracking result can be achieved. At the beginning of each tracking, code discriminator optimization is carried out considering the precise of initial carrier and code phase. For the convenience of optimization, a performance evaluation algorithm of dot-product power code discriminator for band limited signal is proposed. Compared with several existing tracking algorithms which exploit received signal only once, simulation results show the superiority of our proposed iterative tracking algorithm, under data-aided and non-data-aided conditions respectively.