Index Modulation Based on Four-Dimensional Spherical Code and Its DNN-Based Receiver Design

A novel index modulation with spherical code and its constellation mapping are proposed. We derive the closed form of the approximation bound of the bit error rate (BER) of the OFDM-IM system based on four-dimensional spherical code. Our derived BER is very close to the simulation results. And different constellation mapping method have different BER performance and the gap is less than 0.2 dB. To reduce the detection complexity which is caused by the high-dimensional modulation, a DNN-based receiver with partial-connected layer is proposed. Simulation results show that our proposed DNN-based receiver can greatly reduce the complexity while its BER performance is close to the classical maximum likelihood detection method.