Patent ID: 8406325

Claim:
A receiver used for an orthogonal frequency-division multiplexing (OFDM) system, comprising: a signal processing device receiving an OFDM symbol and processing the OFDM symbol according to the OFDM symbol and a carrier frequency offset compensation coefficient to generate a processed signal, wherein the OFDM symbol comprises pilots which have been hierarchically modulated and the processed signal comprises processed pilots; a signal analysis device collecting the processed pilots of the processed signal and detecting a carrier frequency offset to generate the carrier frequency offset compensation coefficient to the signal processing device according to the processed pilots and a plurality of target decision bit error rates; and a channel detection module detecting a channel response of the processed signal according to the processed pilots and compensating the processed signal to generate an output data, wherein the signal processing device comprises a pilot signal collector collecting the processed pilots of the processed signal, a hierarchical pilot signal demodulator demodulating the processed pilots, and a pilot signal analysis module determining a signal and noise ratio according to the demodulated processed pilots, and detecting the carrier frequency offset to generate the carrier frequency offset compensation coefficient to the signal processing device according to the demodulated processed pilots and the target decision bit error rates when the signal and noise ratio exceeds a predetermined value.