An inter-cell interference reduction method for downlink cellular networks based on signal autocorrelation

Since the intra-cell interference can be nearly eliminated by OFDM, the inter-cell interference (ICI) has dominated the cellular networks and greatly degraded the system performance. In this paper, an ICI reduction method based on signal autocorrelation is proposed. In this method, the transmission signals from different cells may overlap in time and frequency, but they are processed to have linearly independent autocorrelation function by adopting a distinguishing pre-filter in each cell. Hence the downlink ICI from adjacent cells can be significantly eliminated by autocorrelation matched filter. To ease the requirement of multiple receiving antennas at the mobile stations, a modified method is proposed to suppress the strongest ICI from the nearest adjacent cell, which only requires 2 antennas equipped at the mobile station. The modified method is especially efficient for the edge cell users.