Multichannel Sharing and Joint Detection for Cell-Edge Users in Downlink Multicell OFDMA Systems

Cell-edge users in cellular systems suffer from intercell interference (ICI), and their data rates are usually lower than those of the users who are close to base stations (BSs). Since data rates cannot be improved by merely increasing transmission power in the presence of ICI, the interference management and alignment become crucial for cell-edge users. However, when channel state information (CSI) is not available at BSs, it is difficult to apply interference alignment techniques. In this paper, we consider a simple approach where each BS in coordination transmits signals to a dedicated user through multiple subcarriers shared by adjacent BSs, which results in an interference channel, so that higher diversity can be exploited for better performance. Using joint detection at users, we show that a reasonable performance can be achieved.