Receiver synchronizer
First Claim
1. A receiver, wherein the receiver receives a received signal, wherein the received signal includes data and a pilot up chirp and a pilot down chirp, wherein the pilot up chirp and the pilot down chirp are concurrent with the data, the receiver comprising:
- a detector arranged to correlate the received signal with a reference up chirp and a reference down chirp, wherein the reference up chirp corresponds to the pilot up chirp, and wherein the reference down chirp corresponds to the pilot down chirp; and
, a signal adjuster arranged to synchronize the receiver to the received signal in response to the correlation performed by the detector.
1 Assignment
0 Petitions
Accused Products
Abstract
A receiver receives a received signal containing a pilot up chirp and a pilot down chirp. The pilot up chirp has a frequency which increases from a time reference zero to a time reference tN, and the pilot down chirp has a frequency which decreases from the time reference tN to a time reference 2ttN. A sampler of the receiver is arranged to sample the received signal. A detector is arranged to correlate the received signal samples with a reference up chirp and a reference down chirp. The reference up chirp has a varying frequency substantially matching the pilot up chirp, and the reference down chirp has a varying frequency substantially matching the pilot down chirp. A sample adjuster is arranged to synchronize the received signal samples in response to the detector.
-
Citations
63 Claims
-
1. A receiver, wherein the receiver receives a received signal, wherein the received signal includes data and a pilot up chirp and a pilot down chirp, wherein the pilot up chirp and the pilot down chirp are concurrent with the data, the receiver comprising:
-
a detector arranged to correlate the received signal with a reference up chirp and a reference down chirp, wherein the reference up chirp corresponds to the pilot up chirp, and wherein the reference down chirp corresponds to the pilot down chirp; and
,a signal adjuster arranged to synchronize the receiver to the received signal in response to the correlation performed by the detector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 48, 49, 50, 51, 52)
wherein F1(s) is a response of the signal adjuster, wherein the signal adjuster and the detector have a response H1(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the signal adjuster and k is gain.
-
-
17. The receiver of claim 1 wherein the detector is arranged to detect a timing error by correlating the received signal with the reference up chirp and the reference down chirp, and wherein the signal adjuster is arranged to correct the timing error in accordance with the following equations:
-
wherein F2(s) is a response of the signal adjuster, wherein the signal adjuster and the detector have a response H2(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the signal adjuster and k is gain.
-
-
18. The receiver of claim 17 wherein the detector is arranged to detect a frequency error by correlating the received signal with the reference up chirp and the reference down chirp, wherein the signal adjuster is arranged to correct the frequency error in accordance with the following equations:
-
wherein F1(s) is another response of the signal adjuster, wherein the signal adjuster and the detector have another response H1(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the signal adjuster and k is gain.
-
-
19. The receiver of claim 18 wherein the detector further comprises a phase error detector arranged to detect a phase error between the received signal and the reference up and down chirps and to produce a phase correction based upon the phase error, wherein the signal adjuster comprises first and second multipliers, wherein the first multiplier multiplies the frequency correction and the phase correction to produce a multiplication result, and wherein the second multiplier multiplies the multiplication result by the received signal.
-
20. The receiver of claim 19 wherein the phase error detector operates in accordance with the following equation:
-
wherein F3(s) is a response of the phase detector, wherein the signal adjuster and the phase detector have a response H3(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the phase error detector and k is gain.
-
-
21. The receiver of claim 18 wherein the signal adjuster further comprises a multiplier and a delay, wherein the multiplier multiplies the frequency correction and the received signal, and wherein the delay advances or retards, as appropriate, an output of the multiplier based upon the timing correction.
-
48. The receiver of claim 1 wherein the pilot up chirp and the pilot down chirp are substantially continuous in the received signal.
-
49. The receiver of claim 1 wherein the detector performs the correlation in the frequency domain.
-
50. The receiver of claim 49 wherein the detector comprises:
-
a Fourier Transform that transforms the received signal into the frequency domain;
a first multiplier that multiplies the frequency domain received signal by the reference up chirp;
a second multiplier that multiplies the frequency domain received signal by the reference down chirp;
a first inverse Fourier Transform that transforms an output of the first multiplier into the time domain; and
,a second inverse Fourier Transform that transforms an output of the second multiplier into the time domain.
-
-
51. The receiver of claim 50 wherein the Fourier Transform comprises a complex Fourier Transform, wherein the first inverse Fourier Transform comprises a first complex inverse Fourier Transform, and wherein the second inverse Fourier Transform comprises a second complex inverse Fourier Transform.
-
52. The receiver of claim 50 wherein the detector further comprises a peak detector that is coupled to outputs of the first and second inverse Fourier Transforms and that detects a Tup-peak correlation value between the pilot up chirp and the reference up chirp and a Tdown-peak correlation value between the pilot down chirp and the reference down chirp.
-
22. A receiver, wherein the receiver receives a received signal containing a pilot up chirp and a pilot down chirp, wherein the pilot up chirp and the pilot down chirp are concurrent with the data, and wherein the receiver comprises:
-
a detector arranged to correlate the received signal with a reference up chirp and a reference down chirp to produce a weighted Tup-peak correlation value and a weighted Tdown-peak correlation value, wherein the reference up chirp has a frequency substantially matching the pilot up chirp, and wherein the reference down chirp has a frequency substantially matching the pilot down chirp; and
,a signal adjuster arranged to synchronize the receiver to the received signal in response to the weighted Tup-peak correlation value and the weighted Tdown-peak correlation value. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 53, 54, 55, 56, 57)
wherein F1(s) is a response of the signal adjuster, wherein the signal adjuster and the detector have a response H1(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the signal adjuster and k is gain.
-
-
34. The receiver of claim 22 wherein the detector is arranged to detect a timing error by correlating the received signal with the reference up chirp and the reference down chirp, and wherein the signal adjuster is arranged to correct the timing error in accordance with the following equations:
-
wherein F2(s) is a response of the signal adjuster, wherein the signal adjuster and the detector have a response H2(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the signal adjuster and k is gain.
-
-
35. The receiver of claim 34 wherein the detector is arranged to detect a frequency error by correlating the received signal with the reference up chirp and the reference down chirp, wherein the signal adjuster is arranged to correct the frequency error in accordance with the following equations:
-
wherein F1(s) is a response of the signal adjuster, wherein the signal adjuster and the detector have a response H1(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the signal adjuster and k is gain.
-
-
36. The receiver of claim 35 wherein the detector further comprises a phase error detector arranged to detect a phase error between the received signal and the reference up and down chirps and to produce a phase correction based upon the phase error, wherein the signal adjuster comprises first and second multipliers, wherein the first multiplier multiplies the frequency correction and the phase correction to produce a multiplication result, and wherein the second multiplier multiplies the multiplication result by the received signal.
-
37. The receiver of claim 36 wherein the phase error detector operates in accordance with the following equation:
-
wherein F3(s) is a response of the phase detector, wherein the signal adjuster and the phase detector have a response H3(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the phase error detector and k is gain.
-
-
38. The receiver of claim 35 wherein the signal adjuster further comprises a multiplier and a delay, wherein the multiplier multiplies the frequency correction and the received signal, and wherein the delay advances or retards, as appropriate, an output of the multiplier based upon the timing correction.
-
53. The receiver of claim 22 wherein the received signal includes data, and wherein the pilot up chirp and the pilot down chirp are concurrent with the data.
-
54. The receiver of claim 53 wherein toe pilot up chirp and the pilot down chirp are substantially continuous in the received signal.
-
55. The receiver of claim 22 wherein the detector comprises:
-
a Fourier Transform that transforms the received signal into the frequency domain;
a first multiplier that multiplies the frequency domain received signal by the reference up chirp;
a second multiplier that multiplies the frequency domain received signal by the reference down chirp;
a first inverse Fourier Transform that transforms an output of the first multiplier into the time domain; and
,a second inverse Fourier Transform that transforms an output of the second multiplier into the time domain.
-
-
56. The receiver of claim 55 wherein the Fourier Transform comprises a complex Fourier Transform, wherein the first inverse Fourier Transform comprises a first complex inverse Fourier Transform, and wherein the second inverse Fourier Transform comprises a second complex inverse Fourier Transform.
-
57. The receiver of claim 55 wherein the detector further comprises a peak detector that is coupled to outputs of the first and second inverse Fourier Transforms and that detects a Tup-peak correlation value between the pilot up chirp and the reference up chirp and a Tdown-peak correlation value between the pilot down chirp and the reference down chirp.
-
39. A method of synchronizing a receiver to a received signal, wherein the received signal contains a pilot up chirp and a pilot down chirp, wherein the pilot up chirp has an increasing frequency, wherein the pilot down chirp has a decreasing frequency, and wherein the method comprises the following steps:
-
a) correlating the received signal with a reference up chirp and a reference down chirp to produce a Tup-peak correlation value and a Tdown-peak correlation value, wherein the reference up chirp has a frequency substantially matching the pilot up chirp, and wherein the reference down chirp has a frequency substantially matching the pilot down chirp;
b) producing a timing error by effectively averaging Tup-peak and Tdown-peak;
c) producing a frequency error by effectively subtracting Tup-peak and Tdown-peak; and
,d) synchronizing the receiver to the received signal in accordance with the timing error and the frequency error. - View Dependent Claims (40, 41, 42, 43, 44, 45, 46, 47, 58, 59, 60, 61, 62, 63)
multiplying the received signal and a frequency correction based upon the frequency error;
and advancing or retarding, as appropriate, a result of the multiplying step in response to a timing correction based upon the timing error.
-
-
41. The method of claim 39 wherein step a) comprises the following steps:
-
sampling the received signal in order to produce received signal samples; and
,correlating the received signal samples with the reference up chirp and the reference down chirp to produce the Tup-peak correlation value and the Tdown-peak correlation value.
-
-
42. The method of claim 41 wherein step d) comprises the following steps:
-
multiplying the received signal samples and a frequency correction based upon the frequency error; and
,advancing or retarding, as appropriate, a result of the multiplying step in response to a timing correction based upon the timing error.
-
-
43. The method of claim 39 wherein step d) comprises the step of correcting the frequency error in accordance with the following equations:
-
wherein F1(s) is a response frequency error corrector, wherein a loop including the frequency error corrector has a response H1(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the frequency error corrector and k is gain.
-
-
44. The method of claim 39 wherein step d) comprises the step of correcting the timing error in accordance with the following equations:
-
wherein F2(s) is a response of a timing error corrector, wherein a loop including the timing error corrector has a response H2(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the timing error corrector and k is gain.
-
-
45. The method of claim 44 wherein step d) comprises the step of correcting the frequency error in accordance with the following equations:
-
wherein F1(s) is a response of a frequency error corrector, wherein a loop including the frequency error corrector has a response H1(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the frequency error corrector and k is gain.
-
-
46. The method of claim 45 further comprising the following steps;
-
detecting a phase error between the received signal and the reference up and down chirps;
producing a phase correction based upon the phase error;
multiplying the frequency correction and the phase correction to produce a multiplication result; and
,multiplying the multiplication result by the received signal.
-
-
47. The method of claim 46 wherein the phase error detecting step comprises the step of detecting the phase error in accordance with the following equation:
-
wherein F3(s) is a response of a phase detector, wherein a loop including the phase detector has a response H3(s) in accordance with the following equation;
and wherein fc is a cut-off frequency of the phase error detector and k is gain.
-
-
58. The method of claim 39 wherein seep a) is performed in the frequency domain.
-
59. The method of claim 39 wherein step a) comprises:
-
a1) transforming the received signal from a first domain to a second domain;
a2) multiplying the received signal in the second domain by the reference up chirp;
a3) multiplying the received signal in the second domain by the reference down chirp;
a4) inverse transforming a result of step a2) from the second domain to the first domain; and
,a5) inverse transforming a result of step a3) from the second domain to the first domain.
-
-
60. The method of claim 59 wherein step a) further comprises:
a) detecting a Tup-peak correlation value between the pilot up chirp and the reference up chirp and a Tdown-peak correlation value between the pilot down chirp and the reference down chirp from results of steps a4) and a5).
-
61. The method of claim 39 wherein step a) comprises:
-
a1) complex transforming the received signal from a first domain to a second domain;
a2) multiplying the received signal in the second domain by the reference up chirp;
a3) multiplying the received signal in the second domain by the reference down chirp;
a4) inverse complex transforming a result of step a2) from the second domain to the first domain; and
,a5) inverse complex transforming a result of step a3) from the second domain to the first domain.
-
-
62. The method of claim 39 wherein the received signal includes data, and wherein the pilot up chirp and the pilot down chirp are concurrent with the data.
-
63. The method of claim 62 wherein the pilot up chirp and the pilot down chirp are substantially continuous in the received signal.
Specification