Study and simulation of the link adaptation technology in the LTE standard

Abstract

The Long Term Evolution first introduced by the link adaptation system as a massive step forward in the control of the network resources. It is mainly based on measuring instantaneous Signal to Interference and Noise Ratio (SINR) which is used to investigated the influence of several parameters on the link adaptation error characteristics. Adaptive Modulation and Coding (AMC) is used to increase the network capacity or downlink data rates. Spatial multiplexing techniques for MIMO antenna configurations are also considered. This report has outlined the various scheduling techniques used in the link adaptation process to increase the throughput of the network. Three major channel state report measurements are used to perform the adaptations which are: CQI (channel quality indicator), PMI (Precoding Matrix Indicator), and RI (Rank Indicator) measurements. An analysis and a comparison of these scheduling algorithms were done through simulations executed on MATLAB software. The impact of the scheduling schemes was examined on the throughput (Average Data Rate) and the Bit Error Rate (BER), and it was compared to the case where no adaptation is done. The fairness of the results given by each scheduling scheme was investigated. The link adaptation improved the transmission robustness through minimizing the error and increased the spectral efficiency to produce a satisfactory average data.