Digital Matched Filter Correlator for Spread Spectrum Speech Communication System
S.L. Maskara, Subbaiah Shanmugavel, Tapan Ray, K. Sudhakar · IETE Technical Review · 1991
Design and implementation of a receiver in a Spread Spectrum (SS) system is the most crucial task. Realization of matched filters using digital chips is shown to be much simpler compared to that using analogue devices, particularly for long codes. Problems of quantization and clock synchronization associated with Digital Matched Filter Correlators (DMFC) have been addressed in this paper. A direct sequence SS system for speech communication has been designed and implemented where the spectrum of the message signal is spread by using 127 length Gold code and the receiver consists of a DMFC. Experimental performance test results of the DMFC carried out in presence of random noise and co-channel interference are presented in this paper. With the use of multiple sampling of the received signal, the performance of the DMFC is found to improve.