Inter-Cell Radio Frame Coordination Scheme Based on Sliding Codebook for 5G TDD Systems

The fifth generation (5G) of the wireless communication networks supports wide diversity of service classes, leading to a highly dynamic uplink (UL) and downlink (DL) traffic asymmetry. Thus, dynamic time division duplexing (TDD) technology has become of a significant importance, due to its radio frame flexibility. However, fully dynamic TDD systems suffer from potentially severe inter-cell cross link interference (CLI). In this paper, we propose a novel inter-cell radio frame coordination (RFC) scheme based on sliding codebook for fully dynamic TDD 5G networks. Proposed coordination scheme simultaneously addresses two optimization objectives of minimizing the average CLI while reliably maximizing the achievable DL/UL capacity, by virtually extending the RFC degrees of freedom through a sliding phase-offset RFC codebook design. Compared to the state-of-the-art TDD studies, the proposed scheme shows significantly improved ergodic capacity, i.e., at least 140% gain under both the TCP and UDP protocols, and with much less signaling overhead, limited to B-bit. The paper offers valuable insights about how to most efficiently pre-mitigate potential CLI in Macro TDD systems.