A reliable intra-relay cooperative relay network coupling with spatial modulation for the dynamic V2V communication

Cooperative relay networks have received much attention recently. Eespecially when the conflicting issue regarding transmission reliability and spectral efficiency becomes serious due to dynamic network topologies, multipath fading effects and high-speed mobility in the vehicular communication networks, the optimal intra-relay cooperation signal processing strategy would play an important role to enable a highly reliable and efficient relay transmission for V2V communications. In this paper, an elaborate intra-relay cooperation structure, called Cooperative Generalized Space Shift Keying using Butson Hadamard matrix (CBHSSK), which can effectively fulfill the coupling of DF relay cooperation with spatial modulation of the active relay nodes in the dynamic relay network has been proposed. According to CBHSSK principle, the active relay selection rule is properly designed and embedded in a joint relay signal vector in addition to a CRC error control. By theoretical derivation of the spectral efficiency of the new strategy, the active ratio relay can be optimized to be adaptive to the nonstationary V2V channel model. Based on the Monte Carlo simulation results by using MRC at ML receiver, the enhanced reliability with low Bit Error Rate (BER) superior to the state-of-art counterpart can be achieved while maintaining the same spectrum efficiency. The optimal design criterions among spectrum efficiency, reliability and power efficiency are also given.