US5265127A
Expired / Lapsed
US
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Non-linear encoder and decoder for information transmission through non-linear channels
Assignee: Nokia Bell Labs
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Filing: 1991-09-03
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Granted: 1993-11-23
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Expires: 2011-09-03
Abstract
Abstract In order to mitigate against the multiplicative noise effects caused by known non-linearities in a trellis coded data transmission system, a signal constellation is formed by starting with a base constellation whose number of signal points and whose geometry are selected in accordance with conventional criteria and then warping that constellation by adjusting the positions of its signal points in accordance with a warp function which is the inverse of the known component of the non-linear characteristic of the transmission system. Because the constellation warping is deterministic, it is possible for the receiver to "unwarp" the received signal points prior to applying them to the Viterbi decoder.
Inventors
- 👤 William L. Betts
- 👤 Burton R. Saltzberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:39
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/32; H04L27/34; H04L27/36; H04L27/366; H04L27/367; H04L27/368; H04L25/00; H04L25/38; H04L25/40; H04L25/49; H04L25/4917; H04L25/4927
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
93 words
Apparatus comprising means for receiving a stream of data, means for generating a sequence of warped signal points which represent the data, each of the warped signal points being related to a respective signal point of a predetermined base constellation in accordance with a predetermined warp function, and means for applying the sequence of warped signal points to a transmission channel having a characteristic which is, at least in part, a non-linear function of the magnitude of signals transmitted over said channel, the warp function being substantially the inverse of that non-linear function.
Claim 2
Dependent Claim
93 words
Apparatus comprising means for receiving a stream of data, means for generating a sequence of warped signal points which represent the data, each of the warped signal points being related to a respective signal point of a predetermined base constellation in accordance with a predetermined warp function, and means for applying the sequence of warped signal points to a transmission channel having a characteristic which is, at least in part, a non-linear function of the magnitude of signals transmitted over said channel, the warp function being substantially the inverse of that non-linear function.
Claim 3
Dependent Claim
24 words
The invention of claim 1 wherein the magnitude of the signal points of the base constellation is an independent variable in the warp function.
Claim 4
Dependent Claim
18 words
The invention of claim 2 wherein a selected warp factor is another independent variable in the warp function.
Claim 5
Dependent Claim
24 words
The invention of claim 2 wherein the warp function is an exponential function of the magnitude of the signal points of the base constellation.
Claim 6
Dependent Claim
14 words
The invention of claim 4 wherein the exponential function is an inverse μ-law function.
Claim 7
Dependent Claim
25 words
The invention of claim 2 wherein the warp function is a hyperbolic sine function of the magnitude of the signal points of the base constellation.
Claim 8
Dependent Claim
126 words
Apparatus for recovering data from a sequence of signal points received from a transmission channel, the characteristic of the channel having a non-linear component, the signal points having been applied to the channel by a transmitter which performs the steps of generating a sequence of warped signal points representing the data and applying the sequence of warped signal points to the channel, each of the warped signal points being related to a respective signal point of a predetermined base constellation in accordance with a warp function derived from the non-linear component of the channel characteristic, the apparatus comprising means for unwarping each of the received signal points using substantially an inverse of the warp function, and means for recovering the data from the unwarped signal points.
Claim 9
Dependent Claim
126 words
Apparatus for recovering data from a sequence of signal points received from a transmission channel, the characteristic of the channel having a non-linear component, the signal points having been applied to the channel by a transmitter which performs the steps of generating a sequence of warped signal points representing the data and applying the sequence of warped signal points to the channel, each of the warped signal points being related to a respective signal point of a predetermined base constellation in accordance with a warp function derived from the non-linear component of the channel characteristic, the apparatus comprising means for unwarping each of the received signal points using substantially an inverse of the warp function, and means for recovering the data from the unwarped signal points.
Claim 10
Dependent Claim
28 words
The invention of claim 7 wherein the recovering means carries out the recovering on the assumption that the unwarped signal points are signal points of the base constellation.
Claim 11
Dependent Claim
41 words
The invention of claim 8 wherein the generating step includes the step of trellis encoding the data, and wherein the recovering means includes means for Viterbi decoding the unwarped signal points using distance metrics computed with respect to the base constellation.
Claim 12
Dependent Claim
21 words
The invention of claim 8 wherein the warp function substantially models the inverse of the non-linear component of the channel characteristic.
Claim 13
Dependent Claim
21 words
The invention of claim 10 wherein said inverse of the warp function substantially models the non-linear component of the channel characteristic.
Claim 14
Dependent Claim
24 words
The invention of claim 8 wherein the magnitude of the signal points of the base constellation is an independent variable in the warp function.
Claim 15
Dependent Claim
41 words
The invention of claim 12 wherein the warp function is an exponential function of the magnitude of the signal points of the base constellation and its inverse function is a logarithmic function of the magnitude of the received warped signal points.
Claim 16
Dependent Claim
22 words
The invention of claim 13 wherein the exponential function is an inverse μ-law function and the logarithmic function is a μ-law function.
Claim 17
Dependent Claim
44 words
The invention of claim 12 wherein the warp function is a hyperbolic sine function of the magnitude of the signal points of the base constellation and its inverse function is an inverse hyperbolic sine function of the magnitude of the received warped signal points.
Claim 18
Dependent Claim
47 words
The invention of claim 7 wherein the transmission channel superimposes multiplicative noise onto the received signal points and wherein the warp function and its inverse are such that the noise superimposed on each unwarped received signal point is substantially independent of its position in said base constellation.
Claim 19
Independent Claim
91 words
A method comprising the steps of receiving a stream of data, generating a sequence of warped signal points which represent the data, each of the warped signal points being related to a respective signal point of a predetermined base constellation in accordance with a predetermined warp function, and applying the sequence of warped signal points to a transmission channel having a characteristic which is, at least in part, a non-linear function of the magnitude of signals transmitted over said channel, the warp function being substantially the inverse of that non-linear function.
Claim 20
Independent Claim
91 words
A method comprising the steps of receiving a stream of data, generating a sequence of warped signal points which represent the data, each of the warped signal points being related to a respective signal point of a predetermined base constellation in accordance with a predetermined warp function, and applying the sequence of warped signal points to a transmission channel having a characteristic which is, at least in part, a non-linear function of the magnitude of signals transmitted over said channel, the warp function being substantially the inverse of that non-linear function.
Claim 21
Dependent Claim
24 words
The invention of claim 17 wherein the magnitude of the signal points of the base constellation is an independent variable in the warp function.
Claim 22
Dependent Claim
18 words
The invention of claim 18 wherein a selected warp factor is another independent variable in the warp function.
Claim 23
Dependent Claim
24 words
The invention of claim 18 wherein the warp function is an exponential function of the magnitude of the signal points of the base constellation.
Claim 24
Dependent Claim
14 words
The invention of claim 20 wherein the exponential function is an inverse μ-law function.
Claim 25
Dependent Claim
25 words
The invention of claim 18 wherein the warp function is a hyperbolic sine function of the magnitude of the signal points of the base constellation.
Claim 26
Independent Claim
128 words
A method of recovering data from a sequence of signal points received from a transmission channel, the characteristic of the channel having a non-linear component, the signal points having been applied to the channel by a transmitter which performs the steps of generating a sequence of warped signal points to the channel, each of the warped signal points warped signal points to the channel, each of the warped signal points being related to a respective signal point of a predetermined base constellation in accordance with a warp function derived from the non-linear component of the channel characteristic, the method comprising the steps of using substantially an inverse of the warp function to unwarp each of the received signal points, and recovering the data from the unwarped signal points.
Claim 27
Independent Claim
128 words
A method of recovering data from a sequence of signal points received from a transmission channel, the characteristic of the channel having a non-linear component, the signal points having been applied to the channel by a transmitter which performs the steps of generating a sequence of warped signal points to the channel, each of the warped signal points warped signal points to the channel, each of the warped signal points being related to a respective signal point of a predetermined base constellation in accordance with a warp function derived from the non-linear component of the channel characteristic, the method comprising the steps of using substantially an inverse of the warp function to unwarp each of the received signal points, and recovering the data from the unwarped signal points.
Claim 28
Dependent Claim
27 words
The invention of claim 23 wherein the recovering step is carried out on the assumption that the unwarped signal points are signal points of the base constellation.
Claim 29
Dependent Claim
42 words
The invention of claim 24 wherein the generating step includes the step of trellis encoding the data, and wherein the recovering step includes the step of Viterbi decoding the unwarped signal points using distance metrics computed with respect to the base constellation.
Claim 30
Dependent Claim
21 words
The invention of claim 24 wherein the warp function substantially models the inverse of the non-linear component of the channel characteristic.
Claim 31
Dependent Claim
18 words
The invention of claim 26 wherein the unwarp function substantially models the non-linear component of the channel characteristic.
Claim 32
Dependent Claim
24 words
The invention of claim 24 wherein the magnitude of the signal points of the base constellation is an independent variable in the warp function.
Claim 33
Dependent Claim
41 words
The invention of claim 28 wherein the warp function is an exponential function of the magnitude of the signal points of the base constellation and its inverse function is a logarithmic function of the magnitude of the received warped signal points.
Claim 34
Dependent Claim
22 words
The invention of claim 29 wherein the exponential function is an inverse μ-law function and the logarithmic function is a μ-law function.
Claim 35
Dependent Claim
44 words
The invention of claim 28 wherein the warp function is a hyperbolic sine function of the magnitude of the signal points of the base constellation and its inverse function is an inverse hyperbolic sine function of the magnitude of the received warped signal points.
Claim 36
Dependent Claim
47 words
The invention of claim 23 wherein the transmission channel superimposes multiplicative noise onto the received signal points and wherein the warp function and its inverse are such that the noise superimposed on each unwarped received signal point is substantially independent of its position in said base constellation.
Claim 37
Independent Claim
111 words
A method of communicating data over a transmission channel whose characteristic has a non-linear component, the method comprising the steps of generating a sequence of warped signal points which represent the data, each of the warped signal points being related to a respective signal point of a predetermined base constellation in accordance with a warp function derived from the non-linear component of the channel characteristic, applying the sequence of warped signal points to the channel, receiving the sequence of warped signal points from the channel, using substantially an inverse of the warp function to unwarp each of the received warped signal points, and recovering the data from the unwarped signal points.
Claim 38
Independent Claim
111 words
A method of communicating data over a transmission channel whose characteristic has a non-linear component, the method comprising the steps of generating a sequence of warped signal points which represent the data, each of the warped signal points being related to a respective signal point of a predetermined base constellation in accordance with a warp function derived from the non-linear component of the channel characteristic, applying the sequence of warped signal points to the channel, receiving the sequence of warped signal points from the channel, using substantially an inverse of the warp function to unwarp each of the received warped signal points, and recovering the data from the unwarped signal points.
Claim 39
Dependent Claim
27 words
The invention of claim 33 wherein the recovering step is carried out on the assumption that the unwarped signal points are signal points of the base constellation.
Claim 40
Dependent Claim
42 words
The invention of claim 34 wherein the generating step includes the step of trellis encoding the data, and wherein the recovering step includes the step of Viterbi decoding the unwarped signal points using distance metrics computed with respect to the base constellation.
Claim 41
Dependent Claim
21 words
The invention of claim 34 wherein the warp function substantially models the inverse of the non-linear component of the channel characteristic.
Claim 42
Dependent Claim
21 words
The invention of claim 36 wherein said inverse of the warp function substantially models the non-linear component of the channel characteristic.
Claim 43
Dependent Claim
24 words
The invention of claim 34 wherein the magnitude of the signal points of the base constellation is an independent variable in the warp function.
Claim 44
Dependent Claim
18 words
The invention of claim 38 wherein the selected warp factor is another independent variable in the warp function.
Claim 45
Dependent Claim
41 words
The invention of claim 38 wherein the warp function is an exponential function of the magnitude of the signal points of the base constellation and its inverse function is a logarithmic function of the magnitude of the received warped signal points.
Claim 46
Dependent Claim
22 words
The invention of claim 40 wherein the exponential function is an inverse μ-law function and the logarithmic function is a μ-law function.
Claim 47
Dependent Claim
44 words
The invention of claim 38 wherein the warp function is a hyperbolic sine function of the magnitude of the signal points of the base constellation and its inverse function is an inverse hyperbolic sine function of the magnitude of the received warped signal points.
Claim 48
Dependent Claim
47 words
The invention of claim 33 wherein the transmission channel superimposes multiplicative noise onto the received signal points and wherein the warp function and its inverse are such that the noise superimposed on each unwarped received signal point is substantially independent of its position in said base constellation.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-22 | 1997-05-24 | 1997-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-22 | 2001-05-24 | 2001-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-22 | 2005-05-24 | 2005-11-23 | $7700.00 | Window Closed / Lapsed |