Interference alignment and cancellation

Abstract

The throughput of existing MIMO LANs is limited by the number of antennas on the AP. This paper shows how to overcome this limitation. It presents interference alignment and cancellation (IAC), a new approach for decoding concurrent sender-receiver pairs in MIMO networks. IAC synthesizes two signal processing techniques, interference alignment and interference cancellation, showing that the combination applies to scenarios where neither interference alignment nor cancellation applies alone. We show analytically that IAC almost doubles the throughput of MIMO LANs. We also implement IAC in GNU-Radio, and experimentally demonstrate that for 2×2 MIMO LANs, IAC increases the average throughput by 1.5x on the downlink and 2x on the uplink. Copyright 2009 ACM.