Non-linear equalizer system and method
First Claim
Patent Images
1. A method of compensating for distortion of a received waveform containing digital symbols at one of a predetermined number of phase angles comprising the steps of:
- (a) receiving at least three successive symbols;
(b) measuring the phase angle of a one of said received symbols;
(c) determining for said one received symbol a reverse phase shift between said one received symbol and an immediately preceding symbol and a forward phase shift between said one received symbol and an immediately succeeding symbol;
(d) modifying the phase angle of said one received symbol as a function of both the reverse and forward phase shifts to thereby compensate for phase distortion of the received waveform.
3 Assignments
0 Petitions
Accused Products
Abstract
A system and method for compensating for angular distortion of a received waveform is disclosed. One embodiment measures the angular position of a current symbol, the preceding symbol and the succeeding symbol, calculates the phase shift between the current symbol and a preceding symbol and the phase shift between the current symbol and a succeeding symbol, uses the phase shifts to enter a 2-D lookup table to extract a phase correction factor, then uses the phase correction factor to modify the angular position of the current symbol.
-
Citations
56 Claims
-
1. A method of compensating for distortion of a received waveform containing digital symbols at one of a predetermined number of phase angles comprising the steps of:
-
(a) receiving at least three successive symbols; (b) measuring the phase angle of a one of said received symbols; (c) determining for said one received symbol a reverse phase shift between said one received symbol and an immediately preceding symbol and a forward phase shift between said one received symbol and an immediately succeeding symbol; (d) modifying the phase angle of said one received symbol as a function of both the reverse and forward phase shifts to thereby compensate for phase distortion of the received waveform. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 32)
-
-
27. A method of equalizing a received waveform containing digital symbols at one of a predetermined number of phase angles comprising the steps of:
-
(a) receiving at least three successive symbols; (b) measuring the phase angle of the received symbols; (c) determining for one of the received symbols a reverse phase shift between said one received symbol and an immediately preceding symbol; (d) determining for said one received symbol a forward phase shift between said one received symbol and an immediately succeeding symbol; (e) providing a two-dimensional lookup table of phase correction factors for all possible combinations of forward and reverse phase angles and thus all possible combinations of reverse and forward phase shifts, indexed by reverse phase shift and forward phase shift; (f) extracting from said lookup table a phase correction factor for the reverse phase shift determined in step (c) and the forward phase shift determined in step (d); (g) modifying the phase angle of said one received symbol by the phase correction factor from step (f) to thereby equalize the received waveform. - View Dependent Claims (28, 29, 30, 31, 33, 34, 35, 36)
-
-
37. A method of reducing intersymbol interference in the form of phase error of a received waveform containing digital symbols at one of a predetermined number of phase angles comprising the steps of:
-
(a) receiving successive symbols; (b) measuring the phase angle of a one of said received symbols; (c) determining for each of a first predetermined number of received symbols preceding said one received symbol a reverse phase shift; (d) determining for each of a second predetermined number of received symbols succeeding said one received symbol a forward phase shift; (e) modifying the phase angle of said one received symbol as a function of the first predetermined number of reverse phase shifts and the second predetermined number of forward phase shifts to thereby reduce the intersymbol interference of the received waveform. - View Dependent Claims (38, 39)
-
-
40. A non-linear equalizer for compensating for distortion of a received waveform containing digital symbols at one of a predetermined number of phase angles comprising:
-
a receiver for receiving at least three successive symbols; measuring means for determining the phase angle of a one of said received symbols; means for determining for said one received symbol a reverse phase shift between said one received symbol and an immediately preceding symbol and a forward phase shift between said one received symbol and an immediately succeeding symbol; means for modifying the phase angle of said one received symbol as a function of both the reverse and forward phase shifts to thereby compensate for phase distortion of the received waveform. - View Dependent Claims (41, 42, 43, 44, 45)
-
-
46. An angular distortion compensator for modifying the phase angle of a digital symbol in a received waveform containing digital symbols at one of a predetermined number of phase angles comprising:
-
a receiver for receiving at least three successive symbols; means for measuring the phase angle of said received symbols; means for determining a phase angle correction factor as a function of the difference in phase angles between one of said received symbols and an immediately preceding symbol and said one of said received symbols and an immediately succeeding symbol; modifying means for modifying the phase angle of said one of said received symbols by the phase angle correction factor to thereby modify the phase angle. - View Dependent Claims (47, 48, 49, 50, 51, 52, 53, 54, 55, 56)
-
Specification