A effective SINR link to system mapping method for CQI feedback in TD-LTE system

Abstract

This paper gives an overview of the so-called link performance model used in TD-LTE (Time Division-Long Term Evolution) system level simulations to determine the link CQI (channel quality Indicator) at reduced complexity of UE (User Equipment). Mainly, effective SINR methods including EESM and MIESM account for the instantaneous channel realization and other configurations and utilize the post processing SINR to compute the effective SNR (Signal to Noise Ratio). Then UE reports CQI values, depending on a linear mapping function from effective SNR to a corresponding CQI value. The simulation shows that EESM and MIESM algorithms bring a similar throughput performance comparing to the ideal CQI choice, but mapping function of EESM method is simpler than MIESM method. Also, EESM method requires all subcarriers to apply the same MCS, which is suitable for TD-LTE system. Therefore, TD-LTE wireless integrated testing instrument adopts EESM method to realize effective SINR link to system mapping.