ADAPTIVE TIME DIVERSITY AND SPATIAL DIVERSITY FOR OFDM

摘要

An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmissio n or for time diversity transmission based on the result of a comparison between threshold values an d at least one of three criteria. The criteria includes a calculation of a smallest eigen valu e of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a rat io of the largest and smallest eigen values of the matrix.