Dynamic Time Division Duplexing for Downlink/Uplink Decoupled Millimeter Wave-Based Cellular Networks

The upcoming 5G cellular network's standard from 3GPP is expected to support the millimeter-wave (mmwave)-based small cell base stations (SCBSs) to increase the data rate and network capacity. Furthermore, the downlink/uplink decoupling (DUDe) has been proposed in 5G to compensate for the transmit power imbalance between the macro-base stations and SCBSs. In this letter, joint uplink and downlink scheduling and resource allocation in a dynamic time division duplex (TDD) system is formulated as an optimization problem. Given a generalized α-fair scheduler, the dynamic TDD and the user scheduling time fractions are derived for a relaxed problem. The derived dynamic TDD results are shown to be a function of the system load. Simulation results are presented, which match with the derived results and show 17% gain in throughput for certain scenarios.