Patent US6396803B2 successfully refreshed from Google Patents.
US6396803B2
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Modulation methods and structures for wireless communication systems and transceivers
Assignee: LG Electronics Inc
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Filing: 2001-03-26
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Granted: 2002-05-28
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Expires: 2021-03-26
Abstract
Abstract Wireless communication methods and structures are provided that enhance communication robustness while reducing cost. They communicate downstream data with orthogonal frequency division multiplexing (OFDM) transmission processes and upstream data with single carrier transmission processes. This combination of transmission processes is configured with various signal modulations (e.g., quadrature phase shift keying (QPSK), m-ary phase shift keying (MPSK) and n-quadrature amplitude modulation (QAM)) to provide lower cost upstream communication from customer services equipments (CPEs) and more robust downstream communication from headends than has been achieved in conventional communication systems. Signal diversity is enhanced by receiving communication signals with multiple antennas that are spatially separated and have different polarizations to thereby enhance frequency diversity. Signal diversity is further enhanced by combining the received signals in ways that maximize the ratio of desired to undesired signals.
Inventors
- 👤 James J. Hornsby
- 👤 Kris Kelkar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:51
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/14; H04L5/143; H04L5/02; H04L5/023
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
75 words
A method of communicating downstream data from a communication headend to a plurality of customer premises equipments (CPEs) and upstream data from said CPEs to said headend, comprising the steps of: conveying said downstream data from said headend to each of said CPEs on a plurality of orthogonal frequency division multiplexed (OFDM) downstream carrier signals; and sending said upstream data from each of said CPEs to said headend on a respective upstream single carrier signal.
Claim 2
Independent Claim
75 words
A method of communicating downstream data from a communication headend to a plurality of customer premises equipments (CPEs) and upstream data from said CPEs to said headend, comprising the steps of: conveying said downstream data from said headend to each of said CPEs on a plurality of orthogonal frequency division multiplexed (OFDM) downstream carrier signals; and sending said upstream data from each of said CPEs to said headend on a respective upstream single carrier signal.
Claim 3
Dependent Claim
55 words
The method of claim 1 , wherein said conveying step includes the steps of: transmitting said OFDM downstream carrier signals from said headend; and receiving said OFDM downstream carrier signals at each of said CPEs with at least two antennas which are spatially separated and have a plurality of polarizations to thereby enhance communication diversity.
Claim 4
Dependent Claim
41 words
The method of claim 2 , wherein said transmitting step includes the step of modulating said downstream data onto said OFDM downstream carrier signals with at least one of quadrature phase shift keying, m-ary phase shift keying and n-quadrature amplitude modulation.
Claim 5
Dependent Claim
26 words
The method of claim 3 , wherein said modulating step includes the step of processing said downstream data with inverse Fourier transforms and error correction codes.
Claim 6
Dependent Claim
26 words
The method of claim 2 , wherein said receiving step includes the step of diversely combining said OFDM downstream carrier signals after reception from said antennas.
Claim 7
Dependent Claim
26 words
The method of claim 2 , wherein said receiving step includes the step of processing said downstream data with fast Fourier transforms and forward error correction.
Claim 8
Dependent Claim
21 words
The method of claim 1 , wherein said sending step includes the step of frequencing hopping said upstream single carrier signal.
Claim 9
Dependent Claim
56 words
The method of claim 1 , wherein said sending step includes the steps of: transmitting a respective upstream single carrier signal from each of said CPEs; and receiving said upstream single carrier signal at said headend with at least two antennas which are spatially separated and have a plurality of polarizations to thereby enhance communication diversity.
Claim 10
Dependent Claim
37 words
The method of claim 8 , wherein said transmitting step includes the step of modulating said upstream data onto said upstream single carrier signal with at least one of quadrature phase shift keying and n-quadrature amplitude modulation.
Claim 11
Dependent Claim
26 words
The method of claim 8 , wherein said receiving step includes the step of diversely combining said OFDM upstream carrier signals after reception from said antennas.
Claim 12
Dependent Claim
26 words
The method of claim 8 , wherein said receiving step includes the step of processing said upstream data with adaptive channel equalization and forward error correction.
Claim 13
Dependent Claim
14 words
The method of claim 11 , wherein said equalization includes spatial and temporal equalization.
Claim 14
Dependent Claim
47 words
The method of claim 1 , further including the step of frequency interleaving OFDM downstream carrier signals and an upstream single carrier signal corresponding to any one of said CPEs with OFDM downstream carrier signals and an upstream single carrier signal corresponding to others of said CPEs.
Claim 15
Dependent Claim
31 words
The method of claim 13 , wherein said interleaving step includes the step of assigning predetermined signal frequencies for each of said CPEs to thereby establish initial communication with said headend.
Claim 16
Dependent Claim
76 words
A communication system for communicating downstream data from a communication headend to a plurality of customer premises equipments (CPEs) and upstream data from said CPEs to said headend, the system comprising: a headend that conveys said downstream data to each of said CPEs on a plurality of orthogonal frequency division multiplexed (OFDM) downstream carrier signals; and a plurality of CPEs that each sends said upstream data to said headend on a respective upstream single carrier signal.
Claim 17
Dependent Claim
76 words
A communication system for communicating downstream data from a communication headend to a plurality of customer premises equipments (CPEs) and upstream data from said CPEs to said headend, the system comprising: a headend that conveys said downstream data to each of said CPEs on a plurality of orthogonal frequency division multiplexed (OFDM) downstream carrier signals; and a plurality of CPEs that each sends said upstream data to said headend on a respective upstream single carrier signal.
Claim 18
Dependent Claim
41 words
The system of claim 15 , wherein said headend includes an OFDM modulator that modulates said downstream data onto said OFDM downstream carrier signals with at least one of quadrature phase shift keying, m-ary phase shift keying and n-quadrature amplitude modulation.
Claim 19
Dependent Claim
25 words
The system of claim 16 , wherein said OFDM modulator is configured to process said downstream data with inverse Fourier transforms and error correction codes.
Claim 20
Dependent Claim
37 words
The system of claim 15 , wherein each of said CPEs includes at least two antennas which are spatially separated and have a plurality of polarizations to thereby receive said OFDM downstream carrier signals with enhanced diversity.
Claim 21
Dependent Claim
65 words
The system of claim 18 , wherein each of said CPEs includes: at least one downconverter that downconverts said OFDM downstream carrier signals to downconverted OFDM downstream carrier signals; a diversity combiner that enhances the received signal strength of said downconverted OFDM downstream carrier signals; and an OFDM demodulator that processes said downconverted OFDM downstream carrier signals with fast Fourier transforms and forward error correction.
Claim 22
Dependent Claim
39 words
The system of claim 15 , wherein each of said CPEs includes a modulator that modulates said upstream data onto its respective upstream single carrier signal with at least one of quadrature phase shift keying and n-quadrature amplitude modulation.
Claim 23
Dependent Claim
30 words
The system of claim 15 , wherein said headend and each of said CPEs include respective media access controllers that facilitate frequency hopping of said respective upstream single carrier signal.
Claim 24
Dependent Claim
35 words
The system of claim 15 , wherein said headend includes at least two antennas which are spatially separated and have a plurality of polarizations to thereby receive said upstream single carrier signal with enhanced diversity.
Claim 25
Dependent Claim
55 words
The system of claim 20 , wherein said headend includes: at least one downconverter that downconverts said upstream single carrier signal to a downconverted upstream single carrier signal; a diversity combiner that enhances the received signal strength of said downconverted upstream single carrier signal; and a demodulator that demodulates said downconverted upstream single carrier signal.
Claim 26
Dependent Claim
51 words
The system of claim 15 , wherein said headend and said CPEs are configured to frequency interleave OFDM downstream carrier signals and an upstream single carrier signal corresponding to any one of said CPEs with OFDM downstream carrier signals and an upstream single carrier signal corresponding to others of said CPEs.
Claim 27
Dependent Claim
33 words
The system of claim 24 , wherein said headend and said CPEs are further configured to assign predetermined signal frequencies for each of said CPEs to thereby establish initial communication with said headend.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-05-27 | 2005-11-26 | 2006-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-05-27 | 2009-11-26 | 2010-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-05-27 | 2013-11-26 | 2014-05-28 | $7700.00 | Window Closed / Lapsed |