Abstract: An orthogonal frequency division multiplexing (OFDM) transmitting apparatus including a signal processing unit, a subcarrier orthogonalization processing unit, and a transmitting unit is provided. The signal processing unit divides a received signal into several real parts and several corresponding imaginary parts. The subcarrier orthogonalization processing unit is coupled to the signal processing unit for receiving the real and the imaginary parts of the signal, and for making the real and the imaginary parts respectively carried by a plurality of different and orthogonal subcarriers. The transmitting unit is coupled to the subcarrier orthogonalization processing unit to transmit the subcarriers.

Abstract: An orthogonal frequency division multiplexing (OFDM) transmitting apparatus including a signal processing unit, a subcarrier orthogonalization processing unit, and a transmitting unit is provided. The signal processing unit divides a received signal into several real parts and several corresponding imaginary parts. The subcarrier orthogonalization processing unit is coupled to the signal processing unit for receiving the real and the imaginary parts of the signal, and for making the real and the imaginary parts respectively carried by a plurality of different and orthogonal subcarriers. The transmitting unit is coupled to the subcarrier orthogonalization processing unit to transmit the subcarriers.

Abstract: An orthogonal frequency division multiplexing (OFDM) system provided for communication includes an OFDM transmitter and an OFDM receiver. The OFDM transmitter may be configured to transmit OFDM signals through a communication channel and may include a channel encoder configured to encode a plurality of information bits and an interleaver configured to interleave the channel-encoded information bits. The OFDM transmitter may also include a mapper configured to map the interleaved channel-encoded information bits into mapped multi-level symbols. The OFDM transmitter may also include a dispersive encoder that is configured to dispersively encode the mapped symbols. The OFDM receiver may be configured to receive the transmitted OFDM signals and to decode the received OFDM signals iteratively based on soft decision methods.