Interference Free Device-to-Device Aided Cooperative Relaying Scheme

We propose an interference free half-duplex cooperative relaying scheme with the aid of device-to-device (D2D) communication by employing spatial modulation (SM), where a D2D user helps the base station (BS) by forwarding the signal of the far user (FU). In phase-I, BS exploits SM to map information bits into two sets: modulation bits (near user's (NU) signal) and antenna index (FU's signal). The iterative-maximum ratio combining (i-MRC) technique is used by NU and D2D user D1 (relay) to de-map their desired information bits. During phase-2, the D2D enabled relay D1 also exploits SM to forward FU's signal received from BS and its own data bits for another D2D user (D2). Then FU and D2 retrieve their desired data by utilizing i-MRC. There will be no interference in and between cellular and D2D communications as SM is invoked both at BS and D1. So, interference cancellation techniques are not needed at the receivers. Finally, through the Monte Carlo simulation, the efficiency of the proposed protocol is demonstrated.