Patent ID: 6434200
Filing Date: 2002-08-13
Classification: H03G,H03M,H04B,H04L

Abstract:
A method of decoding a multidimensional code comprising the steps of:(a) receiving a symbol having at least 16 possible phase angles which includes C coded bits and U uncoded bits; (b) converting the received symbol to a phase angle; (c) achieving a 1/2U reduction in decoding effort by: (1) mapping the phase angles to the first quadrant if the number of uncoded bits is two and to_the first octant if the uncoded bits are three to thereby eliminate the uncoded bits; (2) subtracting the mapped phase angle from the 2C reference angle; (3) converting the absolute value of all phase angles greater than 360/2U+1 to 360/2U minus the phase angle; (4) squaring the absolute value to provide 2C metrics; (d) decoding the coded bits including data and parity bits; (e) removing the effect of the decoded coded bits by: (1) determining the phase angle of the decoded bits; and (2) subtracting the determined phase angle from the received symbol to provide a revised phase angle; (f) determining the revised symbol by: (1) adding 360/2U+1 to the revised phase angle; and (2) adding the uncoded MSBs to decode the data bits to thereby provide an output signal.