Modelling and analysis of link adaptation for LTE-advanced

Abstract

We present the detailed system model for adaptive modulation and coding (AMC) in the physical layer, and hybrid automatic repeat request (HARQ) in the data link layer, which play key roles in link layer of future wireless technologies as for e.g. LTE-Advanced. The packet combining schemes hard combining and weighted hard combining are compared in an attempt to reduce packet error rate (PER) and increase spectral efficiency. Simulation results show that both combining schemes will always keep the required quality of service (QoS) and increase spectral efficiency significantly over the system without AMC/HARQ. Moreover, with severe interference, hard combining will improve the system spectral efficiency more than weighted hard combining.