Patent ID: 6275551
Filing Date: 2001-08-14
Classification: H04L

Abstract:
An apparatus for receiving digital information signals comprising:a signal receiving portion for receiving a digital information signal and for transmitting digital data composed of a series of transmission frames each divided into a plurality of Symbols and including a reference Symbol used for synchronization to obtain a received digital information signal;a reference Symbol data extracting portion for extracting data transmitted through the reference Symbol for each of the transmission frames of digital data obtained from the received digital information signal;a frequency offset detecting portion for producing a first frequency detection output regarding the received digital information signal based on the data transmitted through the reference Symbol for each of the transmission frames and for producing a second frequency offset detection output regarding the received digital information signal based on specific data included in data transmitted in each of the plurality of Symbols; anda frequency synchronizing control portion for reducing a frequency offset of the received digital information signal in response to the first and second frequency offset detection outputs produced by said frequency offset detecting portion,wherein said frequency offset detecting portion checks a correlation between the specific data included in the data transmitted in each of the plurality of Symbols and the specific data included in data transmitted through one of the Symbols delayed by a predetermined time for obtaining a correlation value and for calculating a frequency offset based on a phase of a peak position of an integrated correlation value obtained by performing an integration on the correlation value during a period corresponding to the specific data used for producing the second frequency offset detection output.