Impact of mobility on the performance of dynamic cooperative communications in SC-FDMA systems

Cooperative communication technique has recently gained momentum in the research community. This approach allows mobiles to increase their uplink diversity by relaying data of other users. In this paper, we analyze the impact of the terminal mobility on the system performance of the Single-Carrier Frequency Division Multiple Access (SC-FDMA) in dynamic cooperation transmission scenarios. More precisely, using the Random Way Point (RWP) mobility model and the Effective Exponential SNR Mapping (EESM), we give an analytical expression of the Bit Error Rate (BER) at the destination in terms of the radius of cooperative region and of the users density. We show that for cell radius normalized to one unit, and with the RWP model, the optimal cooperative region radius is equal to 0.8. Compared to the non-cooperative scenario, and depending on the spreading length, the SNR gain obtained through dynamic cooperation can exceed 3 dB. Our results are validated through simulations.