System and method for determining absolute phase of a differentially-encoded, phase-modulated signal

Claim 3

The method of claim 1 wherein said step of storing values representative of the absolute phase values comprises storing said values representative of the absolute phase values in a memory element located within the receiver.

Claim 4

The method of claim 1 wherein said step of storing values representative of the absolute phase values of a predetermined sequence of symbols comprises storing values representative of the absolute phase values of an identification sequence comprised of a set of symbols which forms a portion of a differentially-encoded, phase-modulated signal.

Claim 5

The method of claim 1 wherein said step of comparing comprises the step of correlating the values of the stored set of values representative of the absolute phase values of the predetermined sequence of symbols with a sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver, thereby forming a complex, correlation value which forms the comparison value wherein the complex, correlation value has a phase angle associated therewith.

Claim 6

The method of claim 4 wherein said step of comparing further comprises the preliminary step of quantizing the sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver to form a quantized sequence of symbols thereby, and said step of correlating comprises the step of correlating the values of the stored set of values representative of the absolute phase values of the predetermined sequence of symbols with the quantized sequence of symbols representative of the sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver.

Claim 7

The method of claim 1 comprising the further step of synthesizing transmission of the stored set of values to form a synthesized-transmission set of values.

Claim 8

The method of claim 6 wherein said step of comparing comprises comparing the synthesized-transmission set of values with the sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver, such that the comparison value formed thereby has a phase angle indicative of phase differences between the values of the synthesized-transmission set of values and the sequence of symbols transmitted to the receiver.

Claim 9

The method of claim 1 wherein said step of storing comprises storing values representative of absolute phase values of at least two predetermined sequences of symbols of a portion of a desired, phase-modulated signal to form thereby at least two stored sets of values.

Claim 10

The method of claim 8 wherein said step of comparing comprises the steps of calculating a mean square error value between the sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver and each set of the at least two stored sets of values such that said at least two mean square error values formed thereby each form comparison values.

Claim 11

The method of claim 9 wherein said step of determining the absolute phase value comprises the steps of: determining magnitudes of the mean square error values calculated during said step of calculating; and selecting a value representative of an absolute phase value of a symbol of one of the stored values of the at least two predetermined sequences of symbols, said one of the at least two predetermined sequences of symbols having a mean square error value calculated during said step of calculating comprising the step of comparing of a smallest magnitude.

Claim 12

The method of claim 8 comprising the further steps of applying the stored set of values of the at least two stored sets of values, each of the stored sets of values having the values representative of the absolute phase values of the at least two predetermined sequences of symbols, respectively, to an adaptive filter; and generating error signals responsive thereto.

Claim 13

The method of claim 11 wherein said step of comparing comprises the step of calculating mean square error values of the error signals generated by the adaptive filter.

Claim 14

The method of claim 12 wherein said step of determining the absolute phase value comprises selecting the at least one value associated with one of the at least two predetermined sequences comprising one of the at least two stored sets of values having a mean square error value of a smallest magnitude.

Claim 15

The method of claim 1 comprising the further step of applying a signal indicative of the absolute phase value generated during said step of determining as a training signal to an equalizer.

Claim 18

The system of claim 15 wherein said means for storing values representative of the absolute phase values comprises means for storing said values representative of the absolute phase values in a memory element located within the receiver.

Claim 19

The system of claim 15 wherein said means for storing values representative of the absolute phase values of a predetermined sequence of symbols comprises storing values representative of the absolute phase values of an identification sequence comprised of a set of symbols which forms a portion of a differentially-encoded, phase-modulated signal.

Claim 20

The system of claim 15 wherein said means for comparing comprises means for correlating the values of the stored set of values representative of the absolute phase values of the predetermined sequence of symbols with a sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver, thereby forming a complex, correlation value which forms the comparison value wherein the complex, correlation value has a phase angle associated therewith.

Claim 21

The system of claim 18 wherein said means for comparing further comprises means for quantizing the sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver to form a quantized sequence of symbols thereby and said means for correlating comprising the means for comparing comprises means for correlating the values of the stored set of values representative of the absolute phase values of the predetermined sequence of symbols with the quantized sequence of symbols representative of the sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver.

Claim 22

The system of claim 15 further comprising means for synthesizing transmission of the stored set of values to form a synthesized-transmission set of values.

Claim 23

The system of claim 20 wherein said means for comparing comprises means for comparing the synthesized-transmission set of values generated by said means for synthesizing transmission with the sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver, such that the comparison value formed thereby has a phase angle indicative of phase differences between the values of the synthesized-transmission set of values and the sequence of symbols transmitted to the receiver.

Claim 24

The system of claim 15 wherein said means for storing comprises means for storing values representative of absolute phase values of at least two predetermined sequences of symbols of a portion of a desired, phase-modulated signal to form thereby at least two stored sets of values.

Claim 25

The system of claim 22 wherein said means for comparing comprises means for calculating a mean square error value between the sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver and each set of the at least two stored sets of values such that said at least two mean square error values formed thereby each form comparison values.

Claim 26

The system of claim 23 wherein said means for calculating comprises processor circuitry having an algorithm embodied therein.

Claim 27

The system of claim 23 wherein said means for calculating comprises; means for determining magnitudes of the mean square error values calculated during said step of calculating; and means for selecting a value representative of an absolute phase value of a symbol of one of the stored values of the at least two predetermined sequences of symbols, said one of the at least two predetermined sequences of symbols having a mean square error value of a smallest magnitude.

Claim 28

The system of claim 22 further comprising: means for applying the stored set of values of the at least two stored sets of values, each of the stored sets of values having the values representative of the absolute phase values of the at least two predetermined sequences of symbols, repsectively, to an adaptive filter; and means for generating error signals responsive thereto.

Claim 29

The system of claim 26 wherein said means for comparing comprises means for calculating mean square error values of the error signals generated by the adaptive filter.

Claim 30

The system of claim 27 wherein said means for determining the absolute phase value comprises selecting the at least one value associated with one of the at least two predetermined sequences comprising one of the at least two stored sets of values having a mean square error value of a smallest magnitude.

Claim 31

The system of claim 15 further comprising means for applying a signal indicative of the absolute phase value generated by said means for determining as a training signal.

Claim 32

In a radio receiver having receiver circuitry operative to receive a sequence of symbols forming a portion of a differentially-encoded, phase-modulated signal transmitted thereto, the combination with the radio receive of: a system for determining an absolute phase value of at least one symbol of a differentially-encoded, phase-modulated signal comprised of sequences of symbols transmitted to the receiver, wherein said system comprises: means for storing values, to form thereby a stored set of values, representative of absolute phase values of a predetermined sequence of symbols of a portion of a desired, phase-modulated signal; means for comparing the values of the stored set of values representative of the absolute phase values of the predetermined sequence of symbols with a sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver, thereby forming a comparison value having a phase angle indicative of phase differences between the values of the stored set of values and the sequence of symbols transmitted to the receiver associated therewith; means for quantizing the phase angle associated with the comparison value to form a quantized phase value thereby; and means for calculating an absolute phase value of the at least one symbol of the sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver responsive to a value of the quantized phase value quantized by said means for quantizing.

Claim 33

In a radio receiver having receiver circuitry operative to receive a sequence of symbols forming a portion of a differentially-encoded, phase-modulated signal transmitted thereto, the combination with the radio receive of: a system for determining an absolute phase value of at least one symbol of a differentially-encoded, phase-modulated signal comprised of sequences of symbols transmitted to the receiver, wherein said system comprises: means for storing values, to form thereby a stored set of values, representative of absolute phase values of a predetermined sequence of symbols of a portion of a desired, phase-modulated signal; means for comparing the values of the stored set of values representative of the absolute phase values of the predetermined sequence of symbols with a sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver, thereby forming a comparison value having a phase angle indicative of phase differences between the values of the stored set of values and the sequence of symbols transmitted to the receiver associated therewith; means for quantizing the phase angle associated with the comparison value to form a quantized phase value thereby; and means for calculating an absolute phase value of the at least one symbol of the sequence of symbols of the differentially-encoded, phase-modulated signal transmitted to the receiver responsive to a value of the quantized phase value quantized by said means for quantizing.