05732113 is referenced by 356 patents and cites 10 patents.

A method and apparatus achieves rapid timing synchronization, carrier frequency synchronization, and sampling rate synchronization of a receiver to an orthogonal frequency division multiplexed (OFDM) signal. The method uses two OFDM training symbols to obtain full synchronization in less than two data frames. A first OFDM training symbol has only even-numbered sub-carriers, and substantially no odd-numbered sub-carriers, an arrangement that results in half-symbol symmetry. A second OFDM training symbol has even-numbered sub-carriers differentially modulated relative to those of the first OFDM training symbol by a predetermined sequence. Synchronization is achieved by computing metrics which utilize the unique properties of these two OFDM training symbols. Timing synchronization is determined by computing a timing metric which recognizes the half-symbol symmetry of the first OPDM training symbol. Carrier frequency offset estimation is performed in using the timing metric as well as a carrier frequency offset metric which peaks at the correct value of carrier frequency offset. Sampling rate offset estimation is performed by evaluating the slope of the locus of points of phase rotation due to sampling rate offset as a function of sub-carrier frequency number.

Title
Timing and frequency synchronization of OFDM signals
Application Number
8/666237
Publication Number
5732113
Application Date
June 20, 1996
Publication Date
March 24, 1998
Inventor
Donald C Cox
Stanford
CA, US
Timothy M Schmidl
Stanford
CA, US
Agent
Lumen Intellectual Property Services
Assignee
Stanford University
CA, US
IPC
H04L 7/00
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