Patent ID: 7809097

Claim:
A frame timing synchronization system, comprising: a coarse frame timing synchronizer, comprising: an auto-correlator that generates an auto-correlator output signal based on a received signal, and a sliding window differentiator that generates a sliding window differentiator signal, wherein the coarse frame timing synchronizer detects a peak value of the sliding window differentiator signal and generates a coarse frame timing estimate based on a timing position of the peak value of the sliding window differentiator signal, that is generated by applying first and second moving average windows to the auto-correlator output signal and calculating a difference of magnitude of auto-correlation values of the received signal during the first and second moving average windows; and a fine frame timing synchronizer that operates in a window around the coarse frame timing estimate, comprising: a cross-correlator that generates a cross-correlator output signal based on the received signal, wherein the received signal includes a sum of signals transmitted from a plurality of transmit antennas, and each of the signals from a respective one of the transmit antennas is a cyclic delayed version of an original modulated signal according to a cyclic delay diversity (CDD) scheme, and a signal-to-interference ratio (SIR) metric calculator that generates a SIR metric signal based on the cross-correlator output signal, wherein the SIR metric calculator compares an amount of signal energy in a signal energy window to an amount of interference energy in an interference window to mitigate an error associated with pseudo multi-paths introduced by the CDD scheme; wherein the fine frame timing synchronizer detects a peak value of the SIR metric signal and generates a fine frame timing estimate based on a timing position of the peak value of the SIR metric signal.