Patent ID: 8369389

Claim:
A transceiver for an orthogonal frequency-division multiplexing (OFDM) system, comprising: a signal processing device receiving an OFDM symbol and processing the OFDM symbol to generate a processing signal according to the OFDM symbol, wherein the OFDM symbol having pilots which have been hierarchically modulated and the processing signal having processing pilots; a pilot signal analysis device collecting the processing pilots of the processing signal and demodulating the processing pilots to generate a plurality of levels where one of the plurality of levels comprises at least one refinement bits; a degree difference analysis module generating a plurality of degree differences according to the refinement bits and detecting channel classification according to the degree differences to transmit a channel classification signal; and a channel detection module generating and transmitting a modulation indication signal to another transceiver to adjust modulation scheme according to the channel classification signal, and detecting channel responses of the processed signal according to the processing pilots and compensating the processed signal to generate an output data.