Asynchronous DS-UWB communication using spatiotemporal chaotic sequences

Ali Kotti , Soumaya Meherzi (1) , Sylvie Marcos (1) , Safya Belghith

1 L2S - Laboratoire des signaux et systèmes

In this work we address the effect of spreading sequences and pulse waveforms on the performance of asynchronous direct-sequence (DS) ultra-wideband (UWB) systems. Regarding spreading sequences, we consider the two cases of short and long sequences. We derive the expression of the multi-user interference (MUI) variance using long sequences at the output of a Rake receiver, when propagating through multipath channels. We also propose the use of sequences generated with a family of spatiotemporal chaotic systems, namely Piecewise Coupled Map Lattices (PCML), as spreading sequences. Such sequences are shown to reduce the MUI variance with regard to i.i.d. and Gold sets for both short and long sequences. Simulation results show that the use of long PCML codes in AWGN and multipath fading channels results in an improvement of the system average BER, hence an increase of the system capacity in terms of number of active users.

Domains: Engineering Sciences [physics]; Signal and Image processing; Computer Science [cs]; Signal and Image Processing

Ali Kotti, Soumaya Meherzi, Sylvie Marcos, Safya Belghith. Asynchronous DS-UWB communication using spatiotemporal chaotic sequences. IET Signal Processing, 2011, 23 p. ⟨hal-00561614⟩