Improving the jam resistance performance of UWB impulse radio independently of time hopping codes

The jam resistance performance of ultra wideband impulse radio with binary pulse position modulation and time hopping spread spectrum through a general sequence is analyzed in terms of the processing gain theoretically, assuming the jam interference as a continuous wide sense stationary random process occupying a single band whose bandwidth is much smaller than the impulse radio bandwidth. The general closed form expression for the processing gain is derived analytically, based on which the influences on the processing gain attributed to three classes of impulse radio signal parameters, namely the ultra wideband pulse parameters, the spread spectrum parameters and the modulation parameter, are analyzed. In particular ways are presented to improve the processing gain independently of time hopping codes in terms of choosing optimal ultra wideband pulse and modulation parameters, or selecting optimal spread spectrum parameters when the jam bandwidth is much smaller than the pulse repetition frequency of impulse radio. All of the theoretical analyses are demonstrated by simulations.