US6690747B2 — Method for reference signal generation in the pre…

Claim 1

Independent Claim 168 words

A method for producing a reference signal from a modulated signal, comprising: weighting a set of received antenna signals to form a copy signal corresponding to a remote station, the weighting using a spatial weight vector corresponding to the remote station, the copy signal being in the form of copy signal samples; and determining samples of the reference signal by, for each of a set of sample points: constructing an ideal signal sample from the copy signal at the same sample point, the ideal signal sample having a phase determined from the copy signal at the sample point, with the phase of the ideal signal sample at an initial symbol point set to be an initial ideal signal phase; relaxing the phase of the ideal signal sample towards the copy signal sample phase to produce the phase of the reference signal; and producing the reference signal having the phase of the reference signal produced by relaxing the phase of the ideal signal towards the copy signal sample phase.

Claim 2

Independent Claim 168 words

A method for producing a reference signal from a modulated signal, comprising: weighting a set of received antenna signals to form a copy signal corresponding to a remote station, the weighting using a spatial weight vector corresponding to the remote station, the copy signal being in the form of copy signal samples; and determining samples of the reference signal by, for each of a set of sample points: constructing an ideal signal sample from the copy signal at the same sample point, the ideal signal sample having a phase determined from the copy signal at the sample point, with the phase of the ideal signal sample at an initial symbol point set to be an initial ideal signal phase; relaxing the phase of the ideal signal sample towards the copy signal sample phase to produce the phase of the reference signal; and producing the reference signal having the phase of the reference signal produced by relaxing the phase of the ideal signal towards the copy signal sample phase.

Claim 3

Dependent Claim 22 words

The method in claim 1 wherein the spatial weight vector is determined from the received antenna signals and from the reference signal.

Claim 4

Dependent Claim 30 words

The method in claim 1 wherein the set of received antenna signals is received at a communications station, the communications station including an array of antennas and a spatial processor.

Claim 5

Dependent Claim 26 words

The method in claim 3 wherein the spatial processor includes mechanisms for weighting the set of received antenna signals by a set of corresponding receive weights.

Claim 6

Dependent Claim 24 words

The method in claim 4 wherein each distinct received antenna signal is derived from the signal received at a corresponding antenna of the array.

Claim 7

Dependent Claim 24 words

The method in claim 1 wherein the modulated signal is modulated at symbol points by a modulation scheme that has a finite symbol alphabet.

Claim 8

Dependent Claim 16 words

The method in claim 6 wherein the finite symbol alphabet includes symbols that have different phases.

Claim 9

Dependent Claim 72 words

The method of claim 1 wherein the phase of the ideal signal is determined in constructing an ideal signal sample from the copy signal at the same sample point, sample by sample, the phase of the ideal signal sample at any sample point being determined from the phase of the reference signal at the previous sample point for which said phase is determined, and from a decision based on the copy signal.

Claim 10

Dependent Claim 45 words

The method of claim 1 wherein the initial symbol point is a first valid symbol point in a burst of samples of received antenna signals, and determining samples of the reference signal comprises determining the samples of the reference signal in the forward time direction.

Claim 11

Dependent Claim 45 words

The method of claim 1 wherein the initial symbol point is the last valid symbol point in a burst of samples of received antenna signals, and determining samples of the reference signal comprises determining the samples of the reference signal in the backwards time direction.

Claim 12

Dependent Claim 40 words

The method of claim 1 wherein relaxing the phase of the ideal signal sample towards the phase of the copy signal sample corresponds to adding a filtered version of the difference between the copy signal phase and ideal signal phase.

Claim 13

Dependent Claim 49 words

The method of claim 1 wherein relaxing the phase of the ideal signal sample towards the phase of the copy signal sample corresponds to forming the reference signal sample by adding to the ideal signal sample a filtered version of the difference between the copy signal and ideal signal.

Claim 14

Dependent Claim 60 words

The method of claim 11 wherein the filter is a zero order filter consisting of multiplication by a constant and wherein the phase of the reference signal sample is equal to the phase of the ideal signal added to the multiplication of the difference between the phases of the copy signal sample and the ideal signal sample with a constant.

Claim 15

Dependent Claim 44 words

The method of claim 11 wherein the filter is a linear discrete time filter with a transfer function denoted H(z) in the Z-domain with input to the filter being the difference between the phases of the copy signal sample and the ideal signal sample.

Claim 16

Dependent Claim 27 words

The method of claim 13 wherein the quantity of the difference between the phases of the copy signal sample and the ideal signal sample is phase unwrapped.

Claim 17

Dependent Claim 34 words

The method of claim 13 wherein the quantity of the difference between the phases of the copy signal sample and the ideal signal sample is constrained to be in the range −π to +π.

Claim 18

Dependent Claim 27 words

The method of claim 14 wherein the quantity of the difference between the phases of the copy signal sample and the ideal signal sample is phase unwrapped.

Claim 19

Dependent Claim 34 words

The method of claim 14 wherein the quantity of the difference between the phases of the copy signal sample and the ideal signal sample is constrained to be in the range −π to +π.

Claim 20

Dependent Claim 51 words

The method of claim 12 wherein the filter is a zero order filter consisting of multiplication by a constant so that the reference signal sample is equal to the ideal signal added to the multiplication of the difference between the copy signal sample and the ideal signal sample with a constant.

Claim 21

Dependent Claim 41 words

The method of claim 12 wherein the filter is a linear discrete time filter with a transfer function denoted H(z) in the Z-domain with input to the filter being the difference between the copy signal sample and the ideal signal sample.

Claim 22

Dependent Claim 43 words

The method of claim 14 wherein the filter is a first order filter having a transfer function H  ( z ) = γ + βz - 1 1 - δ   z - 1 where γ, β, and δ are parameters.

Claim 23

Dependent Claim 43 words

The method of claim 20 wherein the filter is a first order filter having a transfer function H  ( z ) = γ + βz - 1 1 - δ   z - 1 where γ, β, and δ are parameters.

Claim 24

Dependent Claim 44 words

The method of claim 13 further comprising correcting the phase of the reference signal sample by an amount dependent on the difference in phase between the previously determined reference signal sample and the previously determined copy signal sample prior to producing the reference signal.

Claim 25

Dependent Claim 42 words

The method of claim 19 further comprising correcting the phase of the reference signal sample by an amount dependent on the difference between the previously determined reference signal sample and the previously determined copy signal sample prior to producing the reference signal.

Claim 26

Dependent Claim 13 words

The method of claim 6 wherein the modulation scheme is phase shift keying.

Claim 27

Dependent Claim 14 words

The method of claim 25 wherein the modulation scheme is differential phase shift keying.

Claim 28

Dependent Claim 15 words

The method of claim 6 wherein the modulation scheme is quadrature amplitude modulation, hereafter QAM.

Claim 29

Independent Claim 63 words

A method, comprising: separating from a set of received antenna signals a copy signal corresponding to a remote station by using a first spatial weight vector corresponding to the remote station; determining from the copy signal a reference signal; and computing a second spatial weight vector by optimizing a cost function, the cost function using the received antenna signals and the reference signal.

Claim 30

Independent Claim 63 words

A method, comprising: separating from a set of received antenna signals a copy signal corresponding to a remote station by using a first spatial weight vector corresponding to the remote station; determining from the copy signal a reference signal; and computing a second spatial weight vector by optimizing a cost function, the cost function using the received antenna signals and the reference signal.

Claim 31

Dependent Claim 30 words

The method in claim 28 wherein the set of received antenna signals is received at a communications station, the communications station including an array of antennas and a spatial processor.

Claim 32

Dependent Claim 26 words

The method in claim 29 wherein the spatial processor includes mechanisms for weighting the set of received antenna signals by a set of corresponding receive weights.

Claim 33

Dependent Claim 24 words

The method in claim 30 wherein each distinct received antenna signal is derived from the signal received at a corresponding antenna of the array.

Claim 34

Dependent Claim 38 words

The method in claim 28 wherein the set of received antenna signals includes a modulated signal transmitted from the remote station, the modulated signal modulated at symbol points by a modulation scheme that has a finite symbol alphabet.

Claim 35

Dependent Claim 16 words

The method in claim 32 wherein the finite symbol alphabet includes symbols that have different phases.

Claim 36

Dependent Claim 23 words

The method of claim 28 wherein the reference signal has substantially the same frequency offset and time alignment as the received antenna signals.

Claim 37

Dependent Claim 50 words

The method of claim 28 , wherein the set of received antenna signals includes a modulated signal transmitted from the remote station, the modulated signal modulated at symbol points by a modulation scheme that has a finite symbol alphabet, the method further including extracting the symbols of the modulated signal.

Claim 38

Dependent Claim 26 words

The method of claim 28 further including performing timing alignment on the received antenna signals prior to separating from the received antenna signals the copy signal.

Claim 39

Dependent Claim 27 words

The method of claim 28 further including performing frequency offset correction on the received antenna signals prior to separating from the received antenna signals the copy signal.

Claim 40

Dependent Claim 27 words

The method of claim 36 further including performing frequency offset correction on the received antenna signals prior to separating from the received antenna signals the copy signal.

Claim 41

Dependent Claim 34 words

The method of claim 28 further comprising separating from the received antenna signals the copy signal at least once, using the second spatial weight vector previously computed instead of the first spatial weight vector.

Claim 42

Dependent Claim 19 words

The method of claim 28 further comprising repeating, at least once, determining from the copy signal the reference signal.

Claim 43

Dependent Claim 101 words

The method of claim 28 further including: estimating a frequency offset and a timing misalignment of the copy signal; and correcting the copy signal for frequency offset and timing misalignment to form a corrected copy signal, wherein determining from the copy signal the reference signal comprises: synthesizing a corrected reference signal that has substantially the same frequency offset and timing alignment as the corrected copy signal; and applying frequency offset and time misalignment to the corrected reference signal to form a frequency offset and time misaligned reference signal having the same frequency offset and time misalignment as the received antenna signals.

Claim 44

Dependent Claim 86 words

The method of claim 28 further including: estimating a timing misalignment of the copy signal; and correcting the copy signal for timing misalignment to form a timing aligned copy signal, wherein determining from the copy signal the reference signal comprises: synthesizing a timing aligned reference signal that has substantially the same timing alignment as the timing-aligned copy signal; and applying time misalignment to the timing aligned reference signal to form a timing misaligned reference signal having substantially the same time alignment as the received antenna signals.

Claim 45

Dependent Claim 91 words

The method of claim 28 further including: estimating the frequency offset of the copy signal, and correcting the copy signal for frequency offset to form a frequency offset corrected copy signal, wherein determining from the copy signal the reference signal comprises: synthesizing a frequency offset corrected reference signal that has substantially the same frequency offset as the frequency offset corrected copy signal; and applying frequency offset to the frequency offset corrected reference signal to form a frequency offset reference signal having substantially the same frequency offset as the received antenna signals.

Claim 46

Dependent Claim 123 words

The method of claim 28 wherein determining from the copy signal the reference signal includes, for each of a set of sample points: constructing an ideal signal sample from the copy signal at the same sample point, the ideal signal sample having a phase determined from the copy signal at the sample point, with the phase of the ideal signal sample at an initial symbol point set to be an initial ideal signal phase; relaxing the phase of the ideal signal sample towards the copy signal sample phase to produce the phase of the reference signal; and producing the reference signal having the phase of the reference signal produced by relaxing the phase of the ideal signal towards the copy signal sample phase.

Claim 47

Dependent Claim 72 words

The method of claim 44 wherein the phase of an ideal signal is determined in constructing an ideal signal sample from the copy signal at the same sample point, sample by sample, the phase of the ideal signal sample at any sample point being determined from the phase of the reference signal at the previous sample point for which said phase is determined, and from a decision based on the copy signal.

Claim 48

Dependent Claim 39 words

The method of claim 44 wherein relaxing the phase of the ideal signal sample towards the phase of the copy signal corresponds to adding a filtered version of the difference between the copy signal phase and ideal signal phase.

Claim 49

Dependent Claim 48 words

The method of claim 44 wherein relaxing the phase of the ideal signal sample towards the phase of the copy signal corresponds to forming the reference signal sample by adding to the ideal signal sample a filtered version of the difference between the copy signal and ideal signal.

Claim 50

Dependent Claim 142 words

The method of claim 43 wherein synthesizing the frequency offset corrected reference signal includes, for each of a set of sample points: constructing an ideal signal sample from the frequency offset corrected copy signal at the same sample point, the ideal signal sample having a phase determined from the frequency offset corrected copy signal at the sample point, with the phase of the ideal signal sample at an initial symbol point set to be an initial ideal signal phase; relaxing the phase of the ideal signal sample towards the frequency offset corrected copy signal sample phase to produce the phase of the frequency offset corrected reference signal; and producing the frequency offset corrected reference signal having the phase of the frequency offset corrected reference signal produced by relaxing the phase of the ideal signal towards the frequency offset copy signal sample phase.

Claim 51

Dependent Claim 81 words

The method of claim 48 wherein the phase of the ideal signal is determined in constructing an ideal signal sample from the frequency offset corrected copy signal at the same sample point, sample by sample, the phase of the ideal signal sample at any sample point being determined from the phase of the frequency offset corrected reference signal at the previous sample point for which said phase is determined, and from a decision based on the frequency offset corrected copy signal.

Claim 52

Dependent Claim 45 words

The method of claim 48 wherein relaxing the phase of the ideal signal sample towards the phase of the frequency offset corrected copy signal corresponds to adding a filtered version of the difference between the frequency offset corrected copy signal phase and ideal signal phase.

Claim 53

Dependent Claim 54 words

The method of claim 48 wherein relaxing the phase of the ideal signal sample towards the phase of the frequency offset corrected copy signal corresponds to forming the reference signal sample by adding to the ideal signal sample a filtered version of the difference between the frequency offset corrected copy signal and ideal signal.

Claim 54

Dependent Claim 136 words

The method of claim 42 wherein synthesizing the timing aligned reference signal includes, for each of a set of sample points: constructing an ideal signal sample from the timing aligned copy signal at the same sample point, the ideal signal sample having a phase determined from the timing aligned copy signal at the sample point, with the phase of the ideal signal sample at an initial symbol point set to be an initial ideal signal phase; relaxing the phase of the ideal signal sample towards the timing aligned copy signal sample phase to produce the phase of the timing aligned reference signal; and producing the timing aligned reference signal having the phase of the timing aligned reference signal produced by relaxing the phase of the ideal signal sample towards the timing aligned copy signal sample phase.

Claim 55

Dependent Claim 78 words

The method of claim 52 wherein the phase of the ideal signal is determined in constructing an ideal signal sample from the timing aligned copy signal at the same sample point, sample by sample, the phase of the ideal signal sample at any sample point being determined from the phase of the timing aligned reference signal at the previous sample point for which said phase is determined, and from a decision based on the timing aligned copy signal.

Claim 56

Dependent Claim 43 words

The method of claim 52 wherein relaxing the phase of the ideal signal sample towards the phase of the timing aligned copy signal corresponds to adding a filtered version of the difference between the timing aligned copy signal phase and ideal signal phase.

Claim 57

Dependent Claim 52 words

The method of claim 52 wherein relaxing the phase of the ideal signal sample towards the phase of the timing aligned copy signal corresponds to forming the reference signal sample by adding to the ideal signal sample a filtered version of the difference between the timing aligned copy signal and ideal signal.

Claim 58

Dependent Claim 47 words

The method of claim 41 wherein synthesizing the corrected reference signal includes: coherently demodulating the corrected copy signal to form signal symbols; and re-modulating the signal symbols to form the corrected reference signal having substantially the same timing alignment and frequency offset as the corrected copy signal.

Claim 59

Dependent Claim 52 words

The method of claim 43 wherein synthesizing the frequency offset corrected reference signal includes: coherently demodulating the frequency offset corrected copy signal to form signal symbols; and re-modulating the signal symbols to form the frequency offset corrected reference signal having substantially the same frequency offset as the frequency offset corrected copy signal.

Claim 60

Dependent Claim 61 words

The method of claim 41 wherein estimating the frequency offset includes: applying a nonlinearity to a set of samples determined from the copy signal; taking a DFT; and determining the shift that when applied to an interpolation function causes the shifted interpolation function to best fit the DFT result, the resulting determined shift being a multiple of the estimated frequency offset.

Claim 61

Dependent Claim 61 words

The method of claim 43 wherein estimating the frequency offset includes: applying a nonlinearity to a set of samples determined from the copy signal; taking a DFT; and determining the shift that when applied to an interpolation function causes the shifted interpolation function to best fit the DFT result, the resulting determined shift being a multiple of the estimated frequency offset.

Claim 62

Independent Claim 91 words

An apparatus comprising: a spatial processor coupled to a weight formation processor to separate a copy signal corresponding to a remote station from a set of received antenna signals using a first spatial weight vector; a reference signal generator coupled to the spatial processor to determine a reference signal from the copy signal; the weight formation processor coupled to the reference signal generator to provide the first spatial weight vector and to compute a second spatial weight vector using the received signal corresponding to the remote station and the reference signal.

Claim 63

Independent Claim 91 words

An apparatus comprising: a spatial processor coupled to a weight formation processor to separate a copy signal corresponding to a remote station from a set of received antenna signals using a first spatial weight vector; a reference signal generator coupled to the spatial processor to determine a reference signal from the copy signal; the weight formation processor coupled to the reference signal generator to provide the first spatial weight vector and to compute a second spatial weight vector using the received signal corresponding to the remote station and the reference signal.

Claim 64

Dependent Claim 21 words

The apparatus in claim 60 wherein the apparatus is a communications station, the communications station further including an array of antennas.

Claim 65

Dependent Claim 23 words

The apparatus in claim 60 wherein the spatial processor weighs the set of received antenna signals by a set of corresponding receive weights.

Claim 66

Dependent Claim 24 words

The apparatus in claim 60 wherein the determined reference signal has substantially the same frequency offset and time alignment as the received antenna signals.

Claim 67

Dependent Claim 43 words

The apparatus in claim 60 further including a timing alignment processor coupled to the spatial processor and weight formation processor to perform timing alignment on the received antenna signals, said spatial processor and weight formation processor using the time aligned received antenna signals.

Claim 68

Dependent Claim 45 words

The apparatus in claim 60 further including a frequency offset correction processor coupled to the spatial processor and weight formation processor to perform frequency offset correction on the received antenna signals, said spatial processor and weight formation processor using the frequency-offset corrected received antenna signals.

Claim 69

Dependent Claim 45 words

The apparatus in claim 64 further including a frequency offset correction processor coupled to the spatial processor and weight formation processor to perform frequency offset correction on the received antenna signals, said spatial processor and weight formation processor using the frequency-offset corrected received antenna signals.

Claim 70

Independent Claim 62 words

An apparatus comprising: a means for separating a copy signal corresponding to a particular remote station from a set of received antenna signals using a spatial weight vector; a means for generating a reference signal from the copy signal; and a means for generating the spatial weight vector using the received signal corresponding to a particular remote station and the reference signal.

Claim 71

Independent Claim 62 words

An apparatus comprising: a means for separating a copy signal corresponding to a particular remote station from a set of received antenna signals using a spatial weight vector; a means for generating a reference signal from the copy signal; and a means for generating the spatial weight vector using the received signal corresponding to a particular remote station and the reference signal.

Claim 72

Dependent Claim 18 words

The apparatus in claim 67 further including a means for aligning the timing of the received antenna signals.

Claim 73

Dependent Claim 19 words

The apparatus in claim 67 further including a means for correcting the frequency offset of the received antenna signals.

Claim 74

Dependent Claim 19 words

The apparatus in claim 68 further including a means for correcting the frequency offset of the received antenna signals.

Claim 75

Dependent Claim 94 words

An article of manufacture, comprising: a machine accessible medium, the machine accessible medium providing instructions that, when executed by a machine, cause the machine to generate a reference signal from a modulated signal by: separating from the received antenna signals a copy signal corresponding to the particular remote station by using an initial spatial weight vector corresponding to the particular remote station; determining from the copy signal a reference signal; and computing a new spatial weight vector by optimizing a cost function, the cost function using the received antenna signals and the reference signal.

Claim 76

Dependent Claim 94 words

An article of manufacture, comprising: a machine accessible medium, the machine accessible medium providing instructions that, when executed by a machine, cause the machine to generate a reference signal from a modulated signal by: separating from the received antenna signals a copy signal corresponding to the particular remote station by using an initial spatial weight vector corresponding to the particular remote station; determining from the copy signal a reference signal; and computing a new spatial weight vector by optimizing a cost function, the cost function using the received antenna signals and the reference signal.

Claim 77

Dependent Claim 24 words

The article of claim 71 , wherein the instructions that, when executed, further cause the machine to extract the symbols of the modulated signal.

Claim 78

Dependent Claim 36 words

The article of claim 71 , wherein the instructions that, when executed, further cause the machine to perform timing alignment on the received antenna signals prior to separating from the received antenna signals the copy signal.

Claim 79

Dependent Claim 37 words

The article of claim 71 , wherein the instructions that, when executed, further cause the machine to perform frequency offset correction on the received antenna signals prior to separating from the received antenna signals the copy signal.

Claim 80

Dependent Claim 37 words

The article of claim 73 , wherein the instructions that, when executed, further cause the machine to perform frequency offset correction on the received antenna signals prior to separating from the received antenna signals the copy signal.

Claim 81

Dependent Claim 46 words

The article of claim 71 , wherein the instructions that, when executed, further cause the machine to repeat separating from the received antenna signals a copy signal at least once, using the second new spatial weight vector previously computed instead of the initial spatial weight vector.

Claim 82

Dependent Claim 29 words

The article of claim 71 , wherein the instructions that, when executed, further cause the machine to repeat, at least once, determining from the copy signal the reference signal.

Claim 83

Dependent Claim 131 words

The article of claim 71 , wherein the instructions that, when executed, further cause the machine to: estimate a frequency offset and a timing misalignment of the copy signal; and correct the copy signal for frequency offset and timing misalignment to form a corrected copy signal, and wherein the instructions that, when executed, cause the machine to determine from a copy signal the reference signal further include instructions that, when executed, cause the machine to: synthesize a corrected reference signal that has substantially the same frequency offset and timing alignment as the corrected copy signal; and apply a frequency offset and time misalignment to the corrected reference signal to form a frequency offset and time misaligned reference signal having the same frequency offset and time misalignment as the received antenna signals.

Claim 84

Dependent Claim 116 words

The article of claim 71 , wherein the instructions that, when executed, further cause the machine to: estimate a timing misalignment of the copy signal; and correct the copy signal for timing misalignment to form a timing aligned copy signal, and wherein the instructions that, when executed, cause the machine to determine from a copy signal the reference signal further include instructions that, when executed, cause the machine to: synthesize a timing aligned reference signal that has substantially the same timing alignment as the timing-aligned copy signal; and apply a time misalignment to the timing aligned reference signal to form a timing misaligned reference signal having substantially the same time alignment as the received antenna signals.

Claim 85

Dependent Claim 121 words

The article of claim 71 , wherein the instructions that, when executed, further cause the machine to: estimate the frequency offset of the copy signal, and correct the copy signal for frequency offset to form a frequency offset corrected copy signal, and wherein the instructions that, when executed, cause the machine to determine from a copy signal the reference signal further include instructions that, when executed, cause the machine to: synthesize a frequency offset corrected reference signal that has substantially the same frequency offset as the frequency offset corrected copy signal; and apply a frequency offset to the frequency offset corrected reference signal to form a frequency offset reference signal having substantially the same frequency offset as the received antenna signals.

Claim 86

Dependent Claim 131 words

The article of claim 71 , wherein the instructions that, when executed, further cause the machine to determine the reference signal for each of a set of sample points by: constructing an ideal signal sample from the copy signal at the same sample point, the ideal signal sample having a phase determined from the copy signal at the sample point, with the phase of the ideal signal sample at an initial symbol point set to be an initial ideal signal phase; relaxing the phase of the ideal signal sample towards the copy signal sample phase to produce the phase of the reference signal; and producing the reference signal having the phase of the reference signal produced by relaxing the phase of the ideal signal sample towards the copy signal sample phase.

Claim 87

Dependent Claim 73 words

The article of claim 81 , wherein the instructions that, when executed, further cause the machine, in constructing an ideal signal sample from the copy signal at the same sample point, to determine sample by sample, the phase of the ideal signal sample at any sample point from the phase of the reference signal at the previous sample point for which said phase is determined and a decision based on the copy signal.

Claim 88

Dependent Claim 56 words

The article of claim 81 , wherein the instructions that, when executed, cause the machine to relax the phase of the ideal signal sample towards the phase of the copy signal, comprise instructions that, when executed, cause the machine to add a filtered version of the difference between the copy signal phase and ideal signal phase.

Claim 89

Dependent Claim 57 words

The article of claim 81 , wherein the instructions, when executed, further cause the machine to relax the phase of the ideal signal sample towards the phase of the copy signal by adding to the ideal signal sample a filtered version of the difference between the copy signal and ideal signal to form the reference signal sample.

Claim 90

Dependent Claim 137 words

The article of claim 80 , wherein the instructions that, when executed, further cause the machine to: construct an ideal signal sample from the frequency offset corrected copy signal at the same sample point, the ideal signal sample having a phase determined from the frequency offset corrected copy signal at the sample point, with the phase of the ideal signal sample at an initial symbol point set to be an initial ideal signal phase; relax the phase of the ideal signal sample towards the frequency offset corrected copy signal sample phase to produce the phase of the frequency offset corrected reference signal; and produce the frequency offset corrected reference signal having the phase of the frequency offset corrected reference signal produced by relaxing the phase of the ideal signal sample towards the frequency offset corrected copy signal.

Claim 91

Dependent Claim 82 words

The article of claim 85 , wherein the instructions that, when executed, further cause the machine, in constructing an ideal signal sample from the frequency offset corrected copy signal at the same sample point, to determine sample by sample, the phase of the ideal signal sample at any sample point from the phase of the frequency offset corrected reference signal at the previous sample point for which said phase is determined and a decision based on the frequency offset corrected copy signal.

Claim 92

Dependent Claim 62 words

The article of claim 85 , wherein the instructions that, when executed, cause the machine to relax the phase of the ideal signal sample towards the phase of the frequency offset corrected copy signal, comprise instructions that, when executed, cause the machine to add a filtered version of the difference between the frequency offset corrected copy signal phase and ideal signal phase.

Claim 93

Dependent Claim 71 words

The article of claim 85 , wherein the instructions that, when executed, cause the machine to relax the phase of the ideal signal sample towards the phase of the frequency offset corrected copy signal, comprise instructions that, when executed cause the machine to form the reference signal sample by adding to the ideal signal sample a filtered version of the difference between the frequency offset corrected copy signal and ideal signal.

Claim 94

Dependent Claim 138 words

The article of claim 79 , wherein the instructions that, when executed, further cause the machine to, for each of a set of sample points: construct an ideal signal sample from the timing aligned copy signal at the same sample point, the ideal signal sample having a phase determined from the timing aligned copy signal at the sample point, with the phase of the ideal signal sample at an initial symbol point set to be an initial ideal signal phase; relax the phase of the ideal signal sample towards the timing aligned copy signal sample phase to produce the phase of the timing aligned reference signal; and produce the timing aligned reference signal having the phase of the timing aligned reference signal produced by relaxing the phase of the ideal signal sample towards the timing aligned copy signal.

Claim 95

Dependent Claim 79 words

The article of claim 89 , wherein the instructions that, when executed, further cause the machine to, in constructing an ideal signal sample from the timing aligned copy signal at the same sample point, sample by sample, determine the phase of the ideal signal sample at any sample point from the phase of the timing aligned reference signal at the previous sample point for which said phase is determined and a decision based on the timing aligned copy signal.

Claim 96

Dependent Claim 60 words

The article of claim 89 , wherein the instructions that, when executed, cause the machine to relax the phase of the ideal signal sample towards the phase of the timing aligned copy signal, comprise instructions that, when executed, cause the machine to add a filtered version of the difference between the timing aligned copy signal phase and ideal signal phase.

Claim 97

Dependent Claim 69 words

The article of claim 89 , wherein the instructions that, when executed, cause the machine, to relax the phase of the ideal signal sample towards the phase of the timing aligned copy signal, comprise instructions that, when executed, cause the machine to form the reference signal sample by adding to the ideal signal sample a filtered version of the difference between the timing aligned copy signal and ideal signal.

Claim 98

Dependent Claim 52 words

The article of claim 78 , wherein the instructions that, when executed, further cause the machine to: coherently demodulate the corrected copy signal to form signal symbols; and re-modulate the signal symbols to form the corrected reference signal having substantially the same timing alignment and frequency offset as the corrected copy signal.

Claim 99

Dependent Claim 54 words

The article of claim 80 , wherein the instructions, when executed, further cause the machine to: coherently demodulate the frequency offset corrected copy signal to form signal symbols; and re-modulate the signal symbols to form the frequency offset corrected reference signal having substantially the same frequency offset as the frequency offset corrected copy signal.

Claim 100

Dependent Claim 72 words

The article of claim 78 , wherein the instructions that, when executed, further cause the machine to estimate the frequency offset by: applying a nonlinearity to a set of samples determined from the copy signal; taking a DFT; and determining the shift that when applied to an interpolation function causes the shifted interpolation function to best fit the DFT result, the resulting determined shift being a multiple of the estimated frequency offset.

Claim 101

Dependent Claim 72 words

The article of claim 80 , wherein the instructions that, when executed, further cause the machine to estimate the frequency offset by: applying a nonlinearity to a set of samples determined from the copy signal; taking a DFT; and determining the shift that when applied to an interpolation function causes the shifted interpolation function to best fit the DFT result, the resulting determined shift being a multiple of the estimated frequency offset.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2007-02-09	2007-08-11	2008-02-10	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2011-02-09	2011-08-11	2012-02-10	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2015-02-09	2015-08-11	2016-02-10	$7700.00	Window Closed / Lapsed

Method for reference signal generation in the presence of frequency offsets in a communications station with spatial processing

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