GF(q) LDPC coded spread dimension scheme for anti-jamming communications

In this paper, a novel spread dimension (SD) communication using orthogonal patterns to transmit information is proposed to achieve the reliable communication with the smarty jamming. A soft demodulator is presented and a posterior probability (APP) according to maximum a posterior probability (MAP) estimation is derived to obtain the soft information for soft iterative decoding. The demodulator is suitable for coherent reception ,non-coherent reception with the channel state information (CSI) and non-coherent reception without CSI. Besides, the capacity of the coded modulation scheme which employs GF(q) LDPC codes is compared with the bit interleaved coded modulation (BICM) scheme using the binary LDPC codes for the SD communication system. We prove that the CM scheme is able to better utilize the soft information and owns a higher achievable rate. Simulation results show that the gain of the q-ary LDPC coded SD system is up to 0.5 dB over AWGN channel and has a very good performance with the smarty jamming.