On the local delay and energy efficiency under decoupled uplink and downlink in HetNets

With the proliferation of the Internet of Things, uplink transmission performance has become more and more important. Moreover, with the traditional coupled uplink (UL)/downlink (DL) access (CUDA) mode, it is becoming hard to improve the system performance of UL in ultra dense heterogeneous networks (UDN, or HetNets). In this paper, we have conducted a UL performance comparison study for the decoupled UL/DL access (DUDA) mode over the CUDA mode in UDN. The key performance indicators of local delay and energy efficiency (EE) were investigated with respect to SIR threshold, ratio of small cell base station (SBS) and macro cell base station (MBS) densities, and fractional power control (FPC) factor. Numerical and simulation results confirm that the local delay is lower and the EE is higher under DUDA than under CUDA, and as such the DUDA mode is superior to the CUDA mode for the UL performance of UDN.