Date Added: Sep 2009
Downlink spatial InterCell Interference Cancellation (ICIC) is considered for mitigating other-cell interference using multiple transmit antennas. A principle question the authors explore is whether it is better to do ICIC or simply standard single-cell beamforming. They explore this question analytically and show that beamforming is preferred for all users when the edge SNR (signal-to-noise ratio) is low (< 0 dB), and ICIC is preferred when the edge SNR is high (> 10 dB), for example in an urban setting. At medium SNR, a proposed adaptive strategy, where multiple base stations jointly select transmission strategies based on the user location, outperforms both while requiring a lower feedback rate than the pure ICIC approach.