Average Effective SNR Mapping in LTE-A Uplink

Link adaptation is an important technique to achieve high throughput in wireless communication systems. Effective SNR mapping (ESM) algorithm is widely used to provide equivalent SNR, which helps to predict the BLER performance. In this paper, we propose a new ESM - average effective SNR mapping (AESM) algorithm, which is applicable and efficient in LTE-A uplink. Compared with the well-known exponential ESM (EESM) algorithm, AESM not only provides good approximation, but also has lower complexity by getting rid of the calibration procedure, and replacing exponential and logarithmic calculation with simply averaging algorithm. We study the relationship between AESM and EESM, and demonstrate that the value of AESM is greater than that of EESM, and the difference between them is monotonically decreasing and non-decreasing function of the calibration factor and the variance of the mapped SNRs or SINRs, respectively. Finally, we apply AESM to link adaptation in LTE-A uplink, and the results illustrate that effective SNR obtained by AESM is almost the same with EESM and the performance of link adaptation is as good as expected.