说明：  本文主要从自适应调制的算法及实现出发，引入了OFDM子载波分组的概念，详细阐述了五种固定阈值算法和子带BER预估计算法的原理及实现，并在此基础上加入自适应编码，实现自适应调制与编码。
(Based on the algorithm and implementation of adaptive modulation, this paper introduces the concept of OFDM subcarrier grouping, elaborates the principle and implementation of five fixed threshold algorithms and subband BER estimation algorithm, and adds adaptive coding to realize adaptive modulation and coding.)