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US5504775A
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Multi-user spread spectrum communication system
Assignee: Koninklijke Philips NV
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Filing: 1994-02-02
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Granted: 1996-04-02
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Expires: 2014-02-02
Abstract
Abstract Multi-user communication system which combines means that implement the spread spectrum coding technique SSC with means that implement the modulation technique of orthogonal frequency-division multiplexing OFDM. This makes it possible to inhance the performance of the SSC system by simplifying certain data processing and data acquisition mechanisms. A preferred use is the use in telephone communication systems between mobile stations and base stations.
Inventors
- 👤 Antoine Chouly
- 👤 Americo Brajal
- 👤 Sabine Jourdan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:54
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/004; H04L1/0056; H04L1/0071; H04J; H04J11/00; H04J13/00; H04J13/0003; H04L27/00; H04L27/26; H04L27/2601; H04L27/2626; H04L27/2627; H04L27/2628; H04L27/2647; H04L27/2649; H04L27/265; H04L5/00; H04L5/02; H04L5/023; H04L5/026
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
117 words
A multi-user communication system including at least one base transceiver station and a plurality of user transceiver stations for communicating a message via a plurality of carriers via said base transceiver station, said system comprising: a first transforming circuit for transforming said message into symbols of a constellation; a coding circuit coupled to said first transforming circuit for coding said symbols with a code by spread spectrum coding; a transmitting circuit for transmitting said coded symbols by modulating by orthogonal frequency-division multiplexing; a receiving circuit for receiving said coded symbols by demodulating by orthogonal frequency-division demultiplexing; a decoding circuit for decoding said demodulated coded symbols; and a second transforming circuit for transforming said symbols into said message.
Claim 2
Dependent Claim
117 words
A multi-user communication system including at least one base transceiver station and a plurality of user transceiver stations for communicating a message via a plurality of carriers via said base transceiver station, said system comprising: a first transforming circuit for transforming said message into symbols of a constellation; a coding circuit coupled to said first transforming circuit for coding said symbols with a code by spread spectrum coding; a transmitting circuit for transmitting said coded symbols by modulating by orthogonal frequency-division multiplexing; a receiving circuit for receiving said coded symbols by demodulating by orthogonal frequency-division demultiplexing; a decoding circuit for decoding said demodulated coded symbols; and a second transforming circuit for transforming said symbols into said message.
Claim 3
Dependent Claim
50 words
The system as claimed in claim 1, wherein said modulating circuit includes a serial-to-parallel device, a fourier transform circuit for applying an inverse fourier transform to said symbols, means for adding protection against echo symbols, a parallel-to-serial device and a circuit coupled to said parallel-to-serial device for adding additional symbols.
Claim 4
Dependent Claim
28 words
The system as claimed in claim 2, wherein said modulating circuit includes a time-division/frequency-division symbol interleaving circuit transform coupled between said serial-to-parallel circuit and said fourier transform circuit.
Claim 5
Dependent Claim
33 words
The system as claimed in claim 2, wherein said demodulating circuit includes a sampling circuit, a serial-to-parallel device coupled to said sampling circuit and a fourier transform device to generated the coded symbols.
Claim 6
Dependent Claim
73 words
A base transceiver station for transmitting a message to a plurality of user transceiver stations via a plurality of carriers, said base transceiver station comprising: a first transforming circuit for transforming said message into symbols of a constellation; a coding circuit coupled to said first transforming circuit for coding said symbols with a code by spread spectrum coding; and a transmitting circuit for transmitting said coded symbols by modulating by orthogonal frequency-division multiplexing.
Claim 7
Dependent Claim
73 words
A base transceiver station for transmitting a message to a plurality of user transceiver stations via a plurality of carriers, said base transceiver station comprising: a first transforming circuit for transforming said message into symbols of a constellation; a coding circuit coupled to said first transforming circuit for coding said symbols with a code by spread spectrum coding; and a transmitting circuit for transmitting said coded symbols by modulating by orthogonal frequency-division multiplexing.
Claim 8
Dependent Claim
33 words
The system as claimed in claim 5, wherein said demodulating circuit includes a sampling circuit, a serial-to-parallel device coupled to said sampling circuit and a fourier transform circuit to generate the coded symbols.
Claim 9
Dependent Claim
23 words
The system as claimed in claim 6, wherein said demodulating means includes a time-division/frequency-division symbol de-interleaving circuit coupled to said fourier transform circuit.
Claim 10
Dependent Claim
15 words
The system of claim 7, wherein said demodulating circuit includes an automatic gain control circuit.
Claim 11
Dependent Claim
28 words
The system of claim 7, wherein said demodulating circuit includes a plurality of automatic gain control circuits, one of said automatic gain control circuits corresponding to each carrier.
Claim 12
Dependent Claim
27 words
The system as claimed in claim 5, wherein said decoding circuit includes automatic gain control circuit, one of said automatic gain control circuits corresponding to each carrier.
Claim 13
Dependent Claim
63 words
A base transceiver station for receiving messages transmitted by a plurality of user transceiver stations as coded symbols via a plurality of carriers, said base transceiver station comprising: a receiving circuit for receiving said coded symbols by demodulating by orthogonal frequency-division demultiplexing; a decoding circuit for decoding said demodulated coded symbols; and a second transforming circuit for transforming said symbols into said message.
Claim 14
Dependent Claim
63 words
A base transceiver station for receiving messages transmitted by a plurality of user transceiver stations as coded symbols via a plurality of carriers, said base transceiver station comprising: a receiving circuit for receiving said coded symbols by demodulating by orthogonal frequency-division demultiplexing; a decoding circuit for decoding said demodulated coded symbols; and a second transforming circuit for transforming said symbols into said message.
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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) | 1999-04-02 | 1999-10-02 | 2000-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-02 | 2003-10-02 | 2004-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-02 | 2007-10-02 | 2008-04-02 | $7700.00 | Window Closed / Lapsed |