Approximated probability density functions for the output signal of coherent matched filter and median filter code acquisition structure in an AWGN channel

Acquisition of code synchronization is the most difficult part in a spread spectrum receiver. This paper describes approximations for the probability density functions for the output signal of the coherent matched filter and median filter code acquisition structure in the AWGN channel. The analysis is based on Gaussian density functions. The important parameters for code acquisition, the probabilities of detection and false alarm, are used as performance measures. The results obtained by the analysis are compared with those achieved simulations. Comparisons are made using both fixed thresholds and fixed false alarm probabilities. The conclusion is that the probabilities can be calculated quite accurately using these approximations. The analysis very easily gives an insight of the density functions