Patent ID: 7028246

Claim:
An OFDM (Orthogonal Frequency Division Multiplexing) communication system comprising: a Reed-Solomon interleaver for dispersing Reed-Solomon symbol elements existing in the same positions, obtained by Reed-Solomon coding input information data blocks, to sub-channels of the OFDM symbols, for interleaving; a sub-channel repeater for converting the interleaved signals to parallel data blocks, repeating the parallel data blocks with a predetermined number of times, and transmitting the repeated data blocks over corresponding sub-channels; a sub-channel assignor for adding the sub-channel data blocks and the pilot sub-channel data blocks, and dynamically assigning sub-channels for transmitting the sub-channel data blocks each time the added sub-channel data blocks are received, according to input time points; a sub-channel scrambler for mapping the assigned sub-channel signals according to a predetermined modulation mode, scrambling pilot sub-channel data blocks among the mapped sub-channel data blocks with a pilot scrambling code, and scrambling the scrambled pilot sub-channel data blocks and the remaining mapped sub-channel data blocks with the scrambling code; a minimum PAPR (Peak-to-Average Power Ratio) selector for IFFT (Inverse Fast Fourier Transformer)-transforming a signal output from the sub-channel scrambler, and selecting sub-channel data blocks having a minimum PAPR among the LEFT-transformed sub-channel data blocks; and antennas for transmitting the sub-channel data blocks output from the selector as an in-phase signal having no phase offset, and alternately transmitting the sub-channel data blocks output from the selector as an in-phase signal having no phase offset and a phase-inversed signal having a 180°-phase offset in a training symbol period.