| 摘要 |
A method of estimating signal quality, the method including the steps of a) taking (110) complex samples of a decoded signal at its symbol rate, b) mapping (130) each of the samples by expressing its phase modulo pi /n where n is an integer equal to the number of points in the signal's symbol constellation divided by 2 and where all of the signal's transmitted constellation points have the same amplitude, c) rotating (140) each of the modulo pi /n samples by - pi /2n, d) calculating (150) the ratio of the imaginary part of each of the rotated samples to its real part, thereby providing an instantaneous square root of an I/C ratio, and e) calculating (170) a variance associated with a plurality of the I/C ratios, thereby estimating the signal quality of the signal. Apparatus (402, 410, 502) implementing the methods of the invention is provided. <IMAGE> |
