Wideband chirp modulation for FH-CDMA wireless systems: Coherent and non-coherent receiver structures

In this paper, we propose a novel signaling scheme based on wideband time-varying chirp signals for frequency-hopped code division multiple access (FH-CDMA) techniques. Our new method has been motivated by the inherent resistance of chirp signals against channel imposed distortions as chirps are bandwidth efficient and robust to fading. Specifically, we combine FH-CDMA with chirp modulation such that every user is identified by a unique set of chirp rates as well as a unique pseudo-noise sequence. Our simulations for additive white Gaussian noise and Rayleigh fading channels successfully demonstrate an increase in performance due to a decrease in multiple access interference. We also propose a signal processing based, non-coherent receiver structure when the chirp rate information is corrupted at the receiver.