Patent ID: 6983027
Filing Date: 2006-01-03
Classification: H04L

Abstract:
1. An OFDM transmit signal receiver comprising: a demodulation circuit configured to receive an OFDM transmit signal containing an information carrier, an additive-information transmission carrier, and a reception-synchronization pilot signal to convert said information carrier, said additive-information transmission carrier, and said reception-synchronization pilot signal into frequency-axial data, said information carrier transmitting information data, said additive-information transmission carrier having a lower multi-valued modulation degree than said information carrier, and said reception-synchronization pilot signal having a lower multi-valued modulation degree than said information carrier; a differential detection circuit configured to conduct detection using a detection-subject symbol of a plurality of symbols indicated at a predetermined interval in the same frequency range and using a symbol ahead said detection-subject symbol by a predetermined time in at least either one output of said additive information transmission carrier and said reception-synchronization pilot signal output from said demodulation circuit; and a first S/N ratio generation circuit configured to generate an S/N ratio based on a detection output provided from said differential detection circuit, said S/N ratio indicating a reception quality of said OFDM transmit signal.