Patent ID: 8345783
Filing Date: 2013-01-01
Classification: H04J,H04L

Abstract:
1. A method, implemented in a system, comprising: obtaining a previous OFDM symbol transmitted on a frequency band; obtaining a current OFDM symbol transmitted on the frequency band; computing a current set of outputs of the current OFDM symbol at a plurality of pilot tones, the plurality of pilot tones comprising a plurality of positive pilot tones and a plurality of negative pilot tones; obtaining a homologous set of Fourier transform outputs of the previous OFDM symbol at the plurality of pilot tones; determining a set of positive tone estimation statistics, corresponding to the plurality of positive pilot tones, the determination performed tone-wise from the elements corresponding to the positive pilot tones of the current set and the homologous elements corresponding to the positive pilot tones of the homologous set; determining a set of negative tone estimation statistics, corresponding to the plurality of negative pilot tones, the determination performed tone-wise from the elements corresponding to the negative pilot tones of the current set and the elements corresponding to the negative pilot tones of the homologous set; refining the set of positive tone estimation statistics by tone-wise scaling each element of the set of positive tone estimation statistics by the magnitude of the homologous element of the set of negative tone estimation statistics; refining the set of negative tone estimation statistics by tone-wise scaling each element of the set of negative tone estimation statistics by the magnitude of the homologous element of the set of positive tone estimation statistics; obtaining a current set of CFO estimates for each homologous pair of negative and positive tones from the set of positive tone estimation statistics and the set of negative tone estimation statistics; and determining a phase rotation for phase compensation from the current set of CFO estimates.