AN ADAPTIVE BEAM-FORMING AND SPACE-FREQUENCY BLOCK CODING TRANSMISSION SCHEME FOR MIMO-OFDMA SYSTEMS

摘要

In a wireless communication system including a base station and multiple mobile stations, a method transmits an orthogonal frequency division multiple access (OFDMA) data frame to the mobile stations. The method includes the steps of (a) at the beginning of the data frame, collecting metrics representing channel conditions for each of the channels; (b) assigning each mobile station to one or more communication channels based on the metrics collected; (c) for each symbol in the frame, calculating an average bit-error-rate for each of a number of transmission modes, and assigning to that symbol the transmission mode corresponding to the lowest calculated average bit-error-rate for that symbol; and (d) transmitting the symbols in the frame according to their respective assigned transmission mode. In addition, a bit-loading optimization step may be carried out in conjunction with the method to determine a modulation order for each symbol to be transmitted.