Signal space coded signaling systems have the potential of achieving significant error-rate improvement without the bandwidth expansion normally encountered when error-correcting codes are used. This paper investigates two such systems by means of computer simulation. A band-limited, nonlinear channel is assumed and both systems exhibit performance improvenment compared to uncoded systems.

A 36-channel digital sonar processor has been designed and constructed based on computer simulation results. For CW pulse operation, 16 stored doppler replicas in ROM units are used for correlation with the received signal. For FM pulse operation, a hard limited replica stored in a ROM is used to correlate with this received signal. The advantage of processing the signals in this way is that the replicas can be adjusted to change the effective filtering characteristic. For example, increasing the length of the stored replica reduces the effective bandwidth. Also, replicas can be changed with range or provide different doppler selections for different beams. Experimental results using ideal and real signals are provided.

A computer simulation study has been performed to evaluate the performance of a variety of digital modulation techniques in transmitting high-rate digital data over a satellite channel. Results are presented showing comparative performance of various techniques in the form of error-rate curves and signal-to-noise ratio (SNR) degradation curves.