Date Added: Aug 2012
The challenge of transmit diversity design for the multiple-antenna fading channel has been met with several novel modulation and error correction techniques in the recent past. Space-time block codes operate on a block of input symbols producing a matrix output over antennas and time. Unlike traditional single-antenna AWGN block codes, full rate space-time block codes do not provide coding gain. Their key feature is the provision of full diversity with extremely low encoder/decoder complexity. In this paper, the authors discuss modulation technique of OFDM in multiple channel diversity. The variable length modulation index of carrier signal is encoded with channel interference and reduction of noise.