SYSTEM FOR OFDM AND METHOD FOR TRANSMIITING DIVERSITY THEREROF

摘要

An OFDM(Orthogonal Frequency Division Multiplexing) system and a transmission diversity method thereof are provided to improve a receiving performance by applying a switching technique for selecting one of an SFBC(Space Frequency Block Coding)-OFDM system and an STBC(Space Time Block Coding)-OFDM system based on a channel characteristic. An OFDM system includes a receiver(200), and a transmitter(100). The receiver estimates a channel, and calculates and regulates an average square root delay spread value and a maximum doppler shift value from an estimated channel spectrum. The receiver outputs a control signal for selecting one of an SFBC-OFDM mode and STBC-OFDM mode based on the regularized maximum doppler shift and average square root delay spread value. The transmitter selects one of encoding schemes of the SFBC-OFDM system and an STBC-OFDM system in response to a control signal, and encodes and transmits the transmission signal in response to a selection mode.