Coordinated training and transmission for improved interference cancellation in a cellular network

Abstract

Interference cancellation or joint detection in cellular systems can be used to improve the quality, capacity, or coverage. Gains may be limited, however, due to the lack of coordination between base stations. This resulting asynchronicity increases channel estimation error and degrades the performance of receivers which mitigate interference. We propose a cellular architecture, using sectored base station antennas, that employs successive time delays to reduce the asynchronicity of interfering transmissions. Training sequence assignments are coordinated among cells to ensure that both signal and interferer are trained. We derive the largest allowable offset correction for both uplink and downlink transmissions according to certain criteria. Examples using ideal cellular layouts are presented along with discussion of application to nonideal terrains.