Performance evaluation of a hybrid spread spectrum system in a hostile land mobile radio channel

A performance evaluation is presented for a hybrid (direct-sequence frequency-hopped) spread-spectrum (SS) operating in a hostile jamming cellular mobile radio environment. The effects of a barrage jammer, Rayleigh fading, and log-normal shadowing on the system performance are discussed. Probability of error expressions for a hybrid BDPSK (binary differential phase shift keying) SS are derived in terms of the channel parameters. The results are compared to those obtained for the same system without fading and shadowing. For a given probability of error, the performance is worse for the case of Rayleigh fading compared to the case of additive white Gaussian noise only. Severe performance degradation is also observed, primarily as a result of fading in a mobile radio channel. Consequently, in order to achieve a high performance level, diversity should be used to reduce the effect of shadowing and fast fading