Performance and Detection of Interleaved OFDM-based Transform Domain Communication System in Multi-user Cognitive Radio Context

Bit error rate (BER) performance of the interleaved orthogonal frequency division multiplexing (OFDM) - based transform domain communication system (TDCS) in multi-user cognitive radio context is analyzed in this paper. For the conventional detection scheme, which simply deals with the interference due to other users as noises, an approximate BER expression and a lower bound are derived in the additive white Gaussian noise (AWGN) channel. Numerical results show that the approximate formula matches the simulated results and the lower bound serves as a very tight bound. Further, an enhanced multi-user detection algorithm based on successive interference cancellation with statistic ordering is proposed for the interleaved OFDM-based TDCS in the multipath fading channel. Its performance advantage over the single user detection is proved through simulations.