Discrete-time Nonlinear Analysis of a Full-digital Code Tracking Loop for Bandlimited Direct-sequence Spread-spectrum Signals
Hyoungsoo Lim, Anna Choi, Kyungwhoon Cheun · International Symposium on Information Theory and its Applications · 1994
Full digital coherent and noncoherent PN code tracking loops using simple decimation are presented for handlimited direct-sequence spread-spectrum systems. Analytic expressions for the MSE (Mean Squared Error) and the MTLL (Mean Time to Lose Lock) of the loops are derived and verified to be extremely accurate via computer simulations. The analysis technique based on Markov chains does not require linearization of the phase detector characteristic giving accurate results down to very low signal-to-noise ratios. Results are presented for a first-order loop. Extension of the results to a second-order loop should be straightforward.