Patent ID: 7822133

Claim:
An Orthogonal Frequency Division Multiplexing (OFDM) receiver comprising: non-delay symbol output means for outputting a symbol of an OFDM signal that has been inputted as a non-delay symbol; delay symbol output means for delaying the symbol of the OFDM signal by a certain period of time T−Tg which is equivalent to a difference between a symbol period T of the inputted OFDM signal and a guard interval period Tg, and outputting the symbol as a delay symbol; first calculation means for calculating a first moving average integration value of the non-delay symbol and the delay symbol during the guard interval period Tg; second calculation means for calculating a second moving average integration value of the non-delay symbol and the delay symbol during an effective symbol period Tu subsequent to the guard interval period Tg; third calculation means for calculating a ratio X between the first moving average integration value and the second moving average integration value; and selection signal generation means for generating a selection signal for selecting one of a plurality of antennas based on the ratio X calculated by the third calculation means; wherein the selection signal generation means generates a signal for switching an antenna when the ratio X calculated by the third calculation means is below a predetermined threshold SL.