Abstract: In view of the defects of poor error performance in traditional correlation delay shift keying, a novel multi-user correlation delay shift keying with no intra-signal interference communication (NISI) system is proposed based on frequency division multiplexing (FDM). In the proposed system, the transmitter uses two branches those are orthogonal to each other and uses serial-parallel converter to transmit multi-bit information in one bit period, and it utilizes FDM to send the linear combination of simple addition and subtraction of two orthogonal chaotic signals and simultaneous information bearing signal. At the receiver, the received signals are noncoherent demodulation with the chaotic signals respectively to recover the multi-bit information signal. The bit error rate (BER) formula over Rayleigh fading channel is derived and Monte Carlo simulation experiments are worked. Theoretical analysis and simulation results show that with the increase of the number of users, the new scheme proposed in this paper can effectively improve BER performance and transmission rate, which indicates the good practical application feasibility.

Key words: frequency division multiplexing (FDM), no intra-signal interference (NISI), multi-user correlation delay shift keying (MU-CDSK), bit error rate (BER), Rayleigh fading channel