Multi-carrier multi-level DCSK communication system based on time-reversal

In order to overcome the shortcomings of low transmission rate in multi-user orthogonal multi-level DCSK (MOM-DCSK) communication system, a novel DCSK-based communication system is proposed. The new system is based on the time-reversal technology, M-ary and quadrature modulation. In this paper, K bits data are mapped to multi-transmission coefficients, distinguished by different Walsh codes and then transmitted on N in-phase and orthogonal carriers. The introduction of time-reversal architecture brings additional benefits such as doubling of band utilization and transmission rates. At the receiver, the received signals are input into moving average filters, in which the added noise variance is greatly reduced, thus reducing the system bit error rate (BER). Theoretical BER under additive white Gaussian noise (AWGN) and multipath Rayleigh fading channels are derived and simulated, which are consistent with the numerical simulation results and prove the correctness of the formula. Compared with various systems, the results show that the proposed system has higher transmission rate and lower BER, which proves the rationality and superiority of the system as well as the feasibility of practical engineering applications.