Patent ID: 7542514

Claim:
A method for adaptive modulation and coding based on second order statistics of channel information in orthogonal frequency divisional multiplexing (OFDM) systems, said method comprises following steps: a) a mobile station determining the largest among a set of adaptation time windows T1, T2, . . . Tn as a current adaptation time window; b) said mobile station receiving a set of pilot signals from a base station in the current adaptation time window, obtaining Signal-to-Noise ratio (SNR) samples based on the set of pilot signals, calculating variance β of the SNR and average value γ of the SNR; c) comparing said variance β of SNR in step b) with threshold values β0, βk, obtaining a final current adaptation time window and a current modulation and coding scheme according to the results from comparison and said average value γ of SNR; d) feeding the final current adaptation time window and the current modulation and coding scheme, which are obtained in step c), back to the base station as parameters for the base station to transmit data next time.