Interference Alignment and Cancellation

By: 
Shyamnath Gollakota, Samuel David Perli, and Dina Katabi
Appears in: 
CCR October 2009

The throughput of existing MIMO LANs is limited by the number of antennas on the AP. This paper shows how to overcome this limita- tion. 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, inter- ference alignment and interference cancellation, showing that the combination applies to scenarios where neither interference align- ment 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 2x2 MIMO LANs, IAC increases the average throughput by 1.5x on the downlink and 2x on the uplink.