Distributed MIMO Interference Cancellation for Interfering Wireless Networks: Protocol and Initial Simulation

Abstract

In this report, the problem of interference in dense wireless network deployments is addressed. Two example scenarios are: 1) overlapping basic service sets (OBSSes) in wireless LAN deployments, and 2) interference among close-by femtocells. The proposed approach is to exploit the interference cancellation and spatial multiplexing capabilities of multiple-input multiple- output (MIMO) links to mitigate interference and improve the performance of such networks. Both semi-distributed and fully distributed protocols for 802.11-based wireless networks standard are presented and evaluated. The philosophy of the approach is to minimize modifications to existing protocols, particularly within client-side devices. Thus, modifications are primarily made at the access points (APs). The semi-distributed protocol was fully implemented within the 802.11 package of ns-3 to evaluate the approach. Simulation results with two APs, and with either one client per AP or two clients per AP, show that within 5 seconds of network operation, our protocol increases the goodput on the downlink by about 50%, as compared against a standard 802.11n implementation.