Semi-blind interference alignment in frequency selective channels

Abstract

This paper proposes an Interference Alignment (IA) scheme in two-user downlink frequency selective broadcasting channels, referred to as semi-blind interference alignment (semi-BIA). Based on the frequency selectivity structure, interference can be aligned at users without precise channel coefficients at the Base Station (BS) nor reconfigurable antennas at users. Compared with traditional interference control schemes, for example, Frequency Division Multiple Access (FDMA), the proposed scheme can obtain more degrees of freedom (DoF), which means the overall throughput is improved. Besides, this semi-BIA scheme can also apply to X channels with two single-antenna transmitters and two single-antenna receivers. Simulation results demonstrate that the proposed scheme performs well in terms of achievable data rate and bit error rate (BER) evaluation.