Methods and apparatus for timing synchronization based on transitional pilot symbols

摘要

Methods and apparatus for timing synchronization based on transitional pilot symbols. In an aspect, a method is provided for time tracking synchronization in an OFDM system. The method includes receiving at least one TDM pilot symbol comprising a plurality of modulated sub-carriers that are configured to provide a channel estimate having a length that extends up to a duration of an FFT used for data transmission. The method also includes determining one or both of an instantaneous and averaged channel estimates from the plurality of modulated sub-carriers, and calculating a timing offset based on one or both of the channel estimates. An apparatus includes a receiver configured to receive the at least one TDM pilot symbol, a channel estimator configured to determine the instantaneous and averaged channel estimates, and a time synchronizer configured to calculate a timing offset based on the channel estimates.

主权项

1. A method for time tracking synchronization in an orthogonal frequency-division multiplex (OFDM) system, the method comprising:
receiving, by a mobile device, at least one time-division multiplexed (TDM) transitional pilot symbol comprising a plurality of modulated sub-carriers that provide a channel estimate having a length that is equal to a duration of an FFT used for data, wherein the at least one TDM transitional pilot symbol provides the channel estimate having the length equal to the duration of the FFT used for data when all sub-carriers of the at least one TDM transitional pilot symbol are modulated as pilots, and wherein the at least one TDM transitional pilot symbol is positioned within a superframe at a boundary between wide area data and local area data; determining an instantaneous channel estimate from the plurality of modulated sub-carriers included in the at least one TDM transitional pilot symbol; and calculating a timing offset based on the instantaneous channel estimate.