| 摘要 |
A phase tracking circuit for use in a receiver having a raw in-phase (I) signal and a raw quadrature (Q) signal, where the raw I and Q signals have M discrete signal levels defining an MxM constellation. The phase tracking circuit corrects a phase error rotation angle phi associated with the MxM constellation. The phase tracking circuit comprising: 1) a phase rotation circuit for receiving and rotating the raw (I,Q) input vectors by an expected correction angle to produce corrected (I*,Q*) vectors; 2) a phase error calculation circuit for rotating each corrected (I*,Q*) vectors into the first quadrant, converting the rotated (I*,Q*) vectors to polar coordinates, subtracting an angle of each converted (I*,Q*) vectors from 45 degrees to produce difference angles, and adding each difference angle to the expected correction angle to produce an estimated correction angle value; and 3) an averaging circuit for calculating an average vector value from N estimated correction angle values, wherein the expected correction angle is derived from the average vector value.
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