Patent ID: 7801084

Claim:
A method comprising: receiving a multi-path Orthogonal Frequency Division Multiplexed (OFDM) signal from a remote mobile wireless device; extracting multiple pilot carriers from the signal; performing a frequency domain analysis on the extracted pilot carriers to determine a Doppler frequency corresponding to the remote mobile wireless device, wherein the Doppler frequency comprises the ratio of the speed of the remote mobile wireless device to the carrier wavelength, wherein performing a frequency domain analysis on the extracted pilot carriers to determine a Doppler frequency corresponding to the remote mobile wireless device comprises: generating a plurality of channel estimates corresponding to the extracted pilot carriers, and performing maximum likelihood estimations ( min f d ⁢ T ⁢ Λ k ⁡ ( f d ⁢ T ) = min f d ⁢ T ⁢ ln ⁢ ⁢ det ⁡ ( R ) +  L H ⁢ H ~ k  2 ) on the plurality of channel estimates, wherein the maximum likelihood estimations utilize L = [ l 1 , 1 0 0 ⋯ 0 l 2 , 1 l 2 , 2 0 ⋯ 0 l 3 , 1 l 3 , 2 l 3 , 3 ⋰ ⋮ ⋮ ⋮ ⋮ ⋰ 0 l M , 1 l M , 2 l M , 3 ⋯ l M , M ] where entries in matrix L are pre-calculated and stored using a pre-determined set of values of f d T; and modifying network functionality based, at least in part, on the speed of the remote mobile wireless device as indicated by the Doppler frequency.