5G Downlink Throughput Enhancement by Beam Consolidation at Vacant Traffic

The 3GPP release for 5G (R15) assigns each User Equipment (UE) a radio beam by employing Massive Multi User Multiple-Input Multiple-Output (MU-MIMO) technology. Each beam carries, at the downlink, a data with a rate according to the Modulation and Coding Scheme (MCS) assigned by the base station (BS). For the limited existence of active UEs and during vacant traffic, all UEs are not active or standby, the assigned beams will be transmitted, but not to any UE. This paper proposes a new scheme that consolidates vacant beams of inactive UEs, to the adjacent beam of the active UE or UE at the cell edge to duplicate the bandwidth of the new beam. The proposed scheme increases the level of desired MCS to a higher scheme (e.g. from Quadrature Phase Shift Keying (QPSK) to Quadrature Amplitude Modulation (QAM)), and hence enhances the spectral efficiency (SE) of the 5G mobile networks. The BS consolidates (combines) multiple radio beams along with the assigned beam during vacant traffic. More than two beams are consolidated in particular to the active UE to increase the bit rate by assigning higher MCS. The simulation evaluation depicts that the performance of beams consolidation provides a gain of 3.5 dB above than the state before beam consolidation. Moreover, more than 40 % improvement in UE throughput is achieved.