Combined fast link adaptation algorithm in LTE systems

Abstract

The Fast Link Adaptation (FLA) algorithm is implemented as Channel Quality Indicator (CQI) selection technique in the 3GPP Long Term Evolution (LTE) system. The presented FLA algorithms are Exponential Effective SNR Mapping (EESM) and Mean Mutual Information per coded Bit (MMIB) which utilize the post-processing Signal-to-Interference plus Noise Ratios (SINR) to compute the effective Signal-to-Noise power Ratio (SNR) and mean Mutual Information (MI) as Link Quality Metric (LQM), respectively. The throughput performance of investigated FLA algorithms are presented in this paper. We also propose a joint FLA algorithm which combines EESM and MMIB algorithms. We present our simulation results and show that the proposed FLA algorithm yields higher throughput performance and Packet Error Rate (PER) estimation accuracy, compared to conventional FLA schemes. Simultaneously, the computation complexity does not increase much.