Research and design of AMC based on SNR estimation in 5G scenarios

Under the premise of ensuring reliability, the continuous growth of wireless service demand has put forward higher requirements for 5G system user capacity and transmission rate, which will inevitably increase the complexity and variability of wireless channel environment. Using fixed MCS is inappropriate for both ideal and unfavorable channel environments. Therefore, resources cost should be minimized based on meeting certain reliability and stability requirements. This paper proposes an adaptive scheme for changing the modulation order and coding rate based on SNR estimation and CQI reporting. The specific operation process is to select the EVM algorithm to obtain the optimal SNR and the corresponding CQI index through the mapping function, for select the CQI-AMC algorithm based on the modulation order and coding rate of CQI. By analyzing simulation data, the CQI-AMC algorithm shows a nearly double increase in average data rate compared to non AMC algorithms, and a significant improvement in average data rate compared to the Rand AMC algorithm with random modulation and demodulation; In terms of BER: Compared to the baseline scheme without adaptation, the BER is significantly improved, but the CQI-AMC algorithm is lower than the Rand AMC algorithm; Based on the CQI-AMC algorithm, the adaptive design compromises between higher data rates and lower error rates, and achieves an optimal result. It has certain reference value in the AMC design of 5G systems.