Enhancing OFDM capacity through Space-Time Coding for MIMO-OFDM

WING This research is looking into new ways to improve the capacity of an OFDM system. The MIMO system uses multiple antennas to simultaneously transmit data, in small pieces to the receiver, which can process the data flow and put them back together. This process, called spatial multiplexing, proportionally boosts the data-transmission speed by a factor equal to the number of transmitting antennas. In addition, since all data is transmitted both in the same frequency band and with separate spatial signatures, this technique utilizes spectrum very efficiently. Performance investigation of the encoding and decoding algorithms for the various codes in an OFDM-MIMO environment is carried out. The system performance is examined in the presence of typical OFDM problems like timing errors, frequency errors and oscillator phase noise. It is shown that using multiple transmit/receive antennas and space-time block coding along with OFDM provides remarkable performance at the expense of almost no extra processing making possible the realization of high bit rates, desirable in a fourth generation system. Along with this, investigation on the encoding and decoding algorithms for the various space-time block codes and layered space-time code like V-BLAST is also done under the scope of the research. (Mohinder Jankiraman)