Mixed Power Control with Directed Assignment (MPCDA), a Method for Interference Reduction in Channelized Wireless Systems

Abstract

Power control, often coupled with dynamic channel assignment, has been viewed as a promising answer to the challenge of reducing interference and increasing capacity. Indiscriminate use of power control, however, may exacerbate the near-far-end problem on the down link, and give rise to other complications when users are mobile. We propose a power control policy that can alleviate the near-far-end interference caused by the use of either the same channel or neighbor channels inside the same cell, while at the same time aiding in the reduction of interference from different cells through user matching. We present a heuristic algorithm for user matching, which is distributed and simple to implement. The method can be combined with an array of either fixed or dynamic channel assignment algorithms and applies to both circuit-based and packet-based traffic. It is ideal for fixed or slow circuit-based traffic and for packet-based traffic. A duality relationship is derived for the proposed power control policy between the signal-to-interference ratio of two interfering users experienced in the two communication directions. This relationship enables one to validate channel assignment decisions on both communication directions by analyzing only the decisions for one.