Mobility effect on the downlink performance of spatial multiplexing techniques under different scheduling algorithms in heterogeneous network

Abstract

LIE addresses the escalating demand of data rates by introducing several multiple-input and multiple-output (MIMO) transmission modes. One of the potential MIMO technique is to send independent data streams over multiple antennas. This is known as spatial multiplexing. The simplest form of spatial multiplexing is open-loop spatial multiplexing (OLSM). The performance of OLSM can be improved further by using an extra feedback information sent back by the user equipment (UE) to the base station (BS). This is termed as closed loop spatial multiplexing (CLSM). Data is transmitted in the form of packets called resource blocks (RBs) and the distribution of RBs among active UEs is determined by the scheduler present at the BS. Scheduler performance ranges from optimizing the UE fairness to maximizing the UE throughput and can have a significant impact on the overall system performance. A prominent constraint that degrades the MIMO performance is the UE mobility. In this paper, we have analyzed various LTE downlink performance parameters between OLSM and CLSM under different scheduler algorithms to conclude which spatial multiplexing and scheduler combination is best suited for mobile users in a heterogeneous network (HetNet).