Optimal power allocation analysis for simulation system based on the N -continuous precoded SM-OFDM system with imperfect channel estimation

In this paper, we build the simulation system for the N-continuous (NC) precoded spatial modulation orthogonal frequency division multiplex (SM-OFDM) system with imperfect channel estimation exploiting MATLAB software. Additionally, we evaluate the optimal power allocation between pilot and data symbols in the system by minimizing the derived theoretical bit error rate (BER) upper bound operating with imperfect channel estimation when employs a pilot design approach which protects the pilot symbols from interference introduced by NC precoder. This is motivated by the fact that since the signals are subjected to the interference introduced by the precoding at each subcarrier in the considered system, the NC precoded SM-OFDM system can’t exploit the exiting optimal power allocation for SM-OFDM system straightly. Numerical simulations show that our pilot design approach outperform the existing pilot design approach,and employing the optimal power allocation achieves a significant gain on BER performance in the NC precoded SM-OFDM system compared to employing the equal power allocation.