SER prediction for DS-IR and DS-UWB in selective channels

We investigate the symbol error rate (SER) of a pulse amplitude modulated (PAM) direct sequence impulse radio (DS-IR) system transmitting over a frequency selective channel and disturbed by thermal noise when the receiver is a correlation receiver with perfect synchronization and channel knowledge. By assuming that the inter symbol interference (ISI) has an approximately Gaussian distribution we derive an expression for the SER that is simple enough to yield insight into the system and to discuss the effect of the system parameters on the performance. The expression also produces good SER estimation over realistic channels as is verified by comparison with Monte Carlo (MC) simulation. The analysis also applies to direct sequence ultra wideband (DS-UWB) and direct sequence spread spectrum (DS-SS) systems since these systems are special cases of the DS-IR system.