A Downlink Non Orthogonal Multiple Access for Chirp Spread Spectrum Communications

In this paper, we aim to enhance the spectral efficiency of Chirp Spread Spectrum (CSS) communications by transmitting simultaneously and on the same bandwidth several non orthogonal signals. Each receiver is able to demodulate its information taking advantage of a controlled time desynchronization between transmitted signals and/or an amplification diversity coupled with a successive interference cancellation algorithm. Various simulation results demonstrate the relevance of our proposition to decode multiple superposed CSS signals in a downlink situation.