A Closed-Loop UL Power Control Scheme for Interference Mitigation in Dynamic TD-LTE Systems

TL;DR

This paper proposes a closed-loop uplink power control scheme for dynamic TD-LTE systems to mitigate interference, using location and subframe info, improving throughput without increasing UE-to-UE interference.

Contribution

It introduces a novel UL power control mechanism based on interference levels, location data, and subframe selection for interference mitigation in dynamic TD-LTE.

Findings

Improves UL average and 5%-ile packet throughput.

Maintains UE-to-UE interference levels despite higher UE transmit power.

Demonstrates effectiveness through system level simulations.

Abstract

The TD-LTE system is envisaged to adopt dynamic time division duplexing (TDD) transmissions for small cells to adapt their communication service to the fast variation of downlink (DL) and uplink (UL) traffic demands. However, different DL/UL directions for the same subframe in adjacent cells will result in new destructive interference components, i.e., eNB-to-eNB and UE-to-UE, with levels that can significantly differ from one subframe to another. In this paper, a feasible UL power control mechanism is proposed to manage eNB-to-eNB interference, where different UL power control parameters are set based on different interference level. We consider the geometric location information and the subframe set selection process about adjacent eNBs when the interference level is estimated. The performance of the proposed scheme is evaluated through system level simulations and it is shown that the scheme can achieve preferable improvement in terms of UL average and 5%-ile packet throughputs compared with the original scheme without power control. Also, the UE-to-UE interference is not worse when the UE transmit power become higher.