Apparatus for receiving digital information signals

• US 6,275,551 B1
• Filed: 07/29/1998
• Issued: 08/14/2001
• Est. Priority Date: 07/31/1997
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nakamura, Jin, Fukami, Tadashi, Tsuruoka, Tatsuya, Nomura, Kiyoshi
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): BURD, KEVIN MICHAEL
• Application Number:
  US09/124,048
• Time in Patent Office: 1,112 Days
• Field of Search: 375/365, 375/344, 370/208
• US Class Current: 375/365
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 27/2675 Pilot or known symbols

Abstract

An apparatus for receiving digital information signals, including 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 segmental periods called symbols and including a reference Symbol for synchronization, a reference Symbol data extracting portion for extracting data transmitted through a reference Symbol 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 based on the received digital information signal a strength of, data transmitted through the, reference Symbol at every transmission frame and obtaining also a second frequency offset detection output based on with the received digital information signal and a strength of specific data included in data transmitted in each of the plurality of 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.

Claims

1. 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; and

a 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.

2. 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; and

a 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 performs a frequency analysis of the data transmitted through the reference Symbol and calculates a frequency offset based on a result of the frequency analysis for obtaining the first frequency offset detection output, and

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.