Apparatus for receiving digital information signals

摘要

An apparatus for receiving digital information signals, which comprises a signal receiving portion for receiving a digital information signal composed of a series of transmission frames each containing a plurality of segmental periods each named Symbol and including a reference Symbol for synchronization, a reference Symbol data extracting portion for extracting data from each of transmission frames of digital data obtained from the received digital information signal, a frequency offset detecting portion for obtaining a first frequency offset detection output in connection with the received digital information signal by determining the strength reference Symbol data at every transmission frame and obtaining also a second frequency offset detection output in connection with the received digital information signal by determining the strength of specific data included in each of a plurality of Symbols at every one of the Symbols, and a frequency synchronizing control portion operative to cause the received digital information signal to have reduced frequency offset in response to the first and second frequency offset detection outputs.