Patent ID: 7570578
Filing Date: 2009-08-04
Classification: H04L

Abstract:
1. An Orthogonal Frequency Division Multiplexing (OFDM) demodulator, comprising: an antenna configured to receive a signal including delayed signals; an estimation circuit configured to estimate a channel response based on the signal received by the antenna; a control circuit configured to control a length of a retention time interval based on the channel response estimated by the estimation circuit, the retention time interval including a time period between a first time when a head of a delayed signal having a maximum delay difference among the delayed signals is received and a second time when a tail of a preceding signal included in the signal received by the antenna is received; a retention memory configured to retain a portion of the signal received by the antenna corresponding to the retention interval; a symbol generation circuit configured to generate OFDM symbol candidates; a conversion circuit configured to convert the OFDM symbol candidates into time domain signals; a replica generation circuit configured to generate replica signals of the signal received by the antenna based on the time domain signals and the channel response estimated by the estimation circuit; a calculation circuit configured to calculate likelihoods that the replica signals are equivalent to the portion of the signal retained in the retention memory; and a selection circuit configured to select an OFDM symbol from the OFDM symbol candidates that corresponds to the replica signal having a maximum likelihood.