Power Control and Interference Awareness Using Busy Bursts

This paper presents the integration of power control and the busy burst (BB) technique for a TDD OFDMA (time division duplex orthogonal frequency division multiple access) system in an urban Manhattan grid type of environment. The objective is to combine power control with the BB protocol to develop a power efficient interference-avoidance technique. Previous work has demonstrated that the time multiplexed BB can be used to achieve interference aware medium access. It has also been demonstrated in other work that the implicit feedback mechanism of BB can be exploited to achieve Pareto optimal SINR-based (signal-to-interference-plus-noise ratio) power control. However, these two applications are not compatible the former depends on fixed signal powers across users, while the latter makes use of variable signal power to achieve optimum power control. This paper proposes an amendment to the BB technique that allows the two approaches to co-exist by exploiting the frequency granularity of OFDMA to frequency multiplex two BBs one with variable and one with fixed power. The resulting control protocol exhibits an eight-fold reduction at the 50th percentile of used energy with no additional overhead as compared to the single BB protocol.