Patents Examined by M. U. Phan
  • Patent number: 7324559
    Abstract: This invention synchronizes the sample clocks of an entire wireless network from a single central base station. Unlike a conventional digital radio network where every terminal must have a synchronization circuit in its receiver to adjust the sample clock, each of the radio terminals in this network is clocked from an independent free-running oscillator. For each terminal, the base station learns the frequency and phase of the oscillator by exchanging a special set of signals: first a vernier signal to determine the initial time and frequency offset, and then an early-late signal to track changes in the oscillator. Once the base station is synchronized to the terminal's oscillator, it can determine the absolute path delay between itself and the terminal and correct for the delay using an equalizer. Signals received from the terminal are corrected after the signal arrives at the base station.
    Type: Grant
    Filed: June 21, 2001
    Date of Patent: January 29, 2008
    Inventor: Grant H. McGibney