Patent ID: 8125885
Filing Date: 2012-02-28
Classification: H04L

Abstract:
1. A method of wireless transmission for estimating the carrier frequency offset in a base station of a received Orthogonal Frequency Division Multiplexing (OFDM) transmission from a user equipment (UE) accessing an Orthogonal Frequency Division Multiplexing Access (OFDMA) radio access network, comprising: receiving a transmission from the UE at one of a plurality of antennas at the base station; extracting selected OFDM symbols from the OFDM symbol multiplex of a received sub-frame employing a-priori known sub-carrier modulation of the selected symbols; computing the frequency-domain symbols received from each antenna through a Fast Fourier Transform (FFT); de-mapping from the frequency-domain symbols the UEs selected sub-carriers of the OFDMA sub-carrier multiplex for each antenna; computing from each de-mapped symbol from each antenna N metrics M performing the steps of receiving, extracting, computing the frequency-domain symbols, de-mapping and computing metrics M non-coherently accumulating across the estimation interval and all antennas the computed metrics M selecting the carrier frequency offset hypothesis with largest accumulated metric amplitude as the estimated carrier frequency offset estimate.