Comparative Study of Two Signal-to-Noise Ratio Calculation Methods in LTE Downlink Simulations

Abstract

It is well-known that the bit error rate (BER) of a mobile communication system is strongly affected by the signal-to-noise ratio (SNR). Because the term SNR is so fundamental that most papers did not explain how SNR is calculatd in simulations. In this paper, we report the BER perfomrance for Long Term Evolution (LTE) downlink simulations with two different SNR calculation methods. It is found that using short-term SNR not only yields much smaller BER than using ensemble-average SNR, but also reverses the ordering of BER performance among the channel models. We thus suggest that in order to fully disclose their implications on performance, the BERs measured against the two SNRs should be presented side by side in LTE downlink simulation studies.