A novel chirp modulation spread spectrum technique for multiple access

This paper proposes a new approach in chirp modulation spread spectrum (CMSS). A good selection of the parameters of the linear chirps, which are used in chirp modulation, combined with antipodal signaling significantly reduces the multiple access interference (MAI) even for small time-bandwidth products. This makes such systems attractive for efficient spread spectrum multiple access. Equal energy and equal bandwidth characterize the set of chirps being used for multiple access. Analytical expressions for the time-bandwidth efficiency and the bit error rate (BER) in additive white Gaussian noise (AWGN) channels are derived. The theoretical results are then confirmed through simulations. The simulation results show that the proposed CMSS technique outperforms existing CMSS techniques in terms of bit error rate and time-bandwidth efficiency. Moreover, its performance approaches those attained by direct sequence spread spectrum (DSSS) systems.