Office of Technology Transfer – University of Michigan

An Enhanced Carrier Frequency Offset/Doppler Shift Estimator for Wireless Access in Vehicular Environments Systems

Technology #3790

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Researchers
Weidong Xiang
Managed By
Drew Bennett
Associate Director - Software Licensing 734-615-4004
Patent Protection
US Patent Pending

Enhanced carrier frequency offset estimator

  • A method is provided for estimating a frequency offset in a carrier signal caused by the Doppler effect. The method determines a frequency offset estimate by utilizing a multi stage estimation scheme. More specifically, the method determines the frequency offset estimate of a data frame by iteratively estimating the frequency offset by comparing different portions of the preamble. As the length of the sampled patterns varies, the frequency offset estimates vary in accuracy and range. The method may adjust frequency offset estimates that are out of range. Finally, the receiver obtains a frequency offset estimate for the data frame from a weighted combination of frequency offset estimates. This method is applicable in WiFi (IEEE 802.11a/g), WiMax (IEEE 802.16), and WAVE (IEEE 802.11p) systems.

  • “US Patent US20090080576”