Feasibility study of a spread from spectrum VHF (SSV) radio for public safety

This study explored the feasibility and limitations of a spread-spectrum very high frequency (VHF) radio (SSV) concept. This SSV concept proposed overlapping the spread-spectrum signal over the VHF narrowband channels. To determine whether the VHF spread-spectrum approach was feasible, the received narrowband interference (NBI) on the SSV receiver performance was calculated and compared with a set of threshold criteria that defined suitable spread-spectrum wireless performance in terms of the signal-to-interference ratio (SIR). The SIR was determined as a function of the SSV´s processing gain and the number of randomly transmitted and randomly located NBI signals operating in the SSV bandwidth. A computational model of the SSV radio system was created with Matlab to simulate the SSV radio environment. The results showed that the high NBI in the VHF band had a significant negative impact on the channel´s potential data throughput capacity and significantly reduced the probability of successful communications