Patent ID: 8559546

Claim:
A method for estimating a residual frequency error in a Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) receiver, the method comprising: (1) estimating, for selected subcarriers of a current symbol of a received signal, an expected vector based on a channel estimate vector and on a reference vector; (2) removing, by phase rotation, a sampling frequency mismatch of the reference vector from the expected vector; (3) calculating a dot product of the estimated expected vector and a received vector; (4) estimating, by an angle estimator, an angle of the calculated dot product; (5) calculating a change in angle from an accumulated phase of a previous symbol, based on the estimated angle of the calculated dot product of the current symbol and an estimated angle of a calculated dot product of the previous symbol; and (6) estimating the residual frequency error based on the calculated change in angle.