A space-time diversity scheme for interference alignment in uplink cellular systems

Interference Alignment (IA) can effectively increase Degrees-of-freedom (DOF) for cellular systems. In order to improve the Bit Error Rate (BER) performance, we propose a space-time diversity scheme for IA in uplink cellular systems. In the proposed scheme, the reference interference vectors at different time slots are randomly selected, thus the channel between each user and Base Station (BS) is transformed to a time varying Single Input Single Output (SISO) equivalent channel and the space diversity is transformed to the time diversity in SISO equivalent channel. Moreover, each user transmits different combinations of user's data at each time slot, and the time diversity gains in time varying SISO equivalent channels are achieved. Theoretical analysis and simulation results show that the proposed scheme can significantly improve BER performance without reducing DOF. © 2015 by Binary Information Press