EP0680168A2
Expired / Lapsed
EP
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System and method for optimizing spectral efficiency using time-frequency-code slicing
Assignee: AT&T Inc
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Filing: 1995-04-27
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Granted: —
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Expires: 2015-04-27
Abstract
Abstract In a system and method for optimizing usage of a communications transmission medium, the transmission medium may be sliced into time (S0-S6) and frequency (F0-F6) domains so as to create time-frequency slices for assignment (by 100) to users (A-T) having varying access rates and user-application requirements. Through scheduling of the various speed users within the frequency and time domains, the system and method can efficiently allocate and make use of the available spectrum, thereby accommodating higher rate users (46) requiring greater bandwidths and time slot assignments while still preserving cost-efficient access for lower speed users (48,50). Depending on the signal modulation scheme, the time-frequency slices may be allocated on non-contiguous frequency bands (e.g., to B). The system and method is also applicable to code-division multiple access (CDMA) techniques by slicing the available code space along time-code domains, frequency-code domains or, in three dimensions, along time-frequency-code domains. Users may be efficiently scheduled based on code space requirements so as to optimize use of the communication medium.
Inventors
- 👤 Richard D. Gitlin
- 👤 Mark J. Karol
- 👤 Zygmunt Haas
- 👤 Clark Woodworth
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 09:22
CPC Classifications
H; H04; H04W; H04W28/00; H04W28/16; H04B; H04B7/00; H04B7/24; H04B7/26; H04B7/2618; H04J; H04J13/00; H04J13/16; H04J4/00; H04L; H04L5/00; H04L5/0001; H04L5/0003; H04L5/0005; H04L5/0014; H04L5/0016; H04W72/00; H04W72/04; H04W72/044; H04W72/0466
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
81 words
A system for optimizing spectral use of a communications transmission medium by a plurality of users of varying user-application and access rates, comprising: means for slicing the communications transmission medium along at least two dimensions; means for slicing the at least two dimensions into a plurality of unit slices in said communications transmission medium; and means for scheduling one or more of said plurality of users in at least one of said plurality of unit slices in said communications transmission medium.
Claim 2
Independent Claim
99 words
A system for optimizing spectral use of a communications transmission medium by a plurality of users of varying user-application and access rates, comprising: a plurality of frequency slices in said communications transmission medium; a plurality of time slices in said communications transmission medium; means for slicing the communications transmission medium into a plurality of time-frequency slices along both said plurality of time slices and said plurality of frequency slices contained in said transmission medium; and means for scheduling one or more of said users in at least one of said plurality of time-frequency slices of said communications transmission medium.
Claim 3
Dependent Claim
26 words
The system in accordance with claim 2, wherein said time-frequency slice comprises one of said frequency slice allocations measured over one of said time slice allocations.
Claim 4
Independent Claim
123 words
A system for optimizing spectral use of a code-division-multiple-access (CDMA) transmission medium by a plurality of users of varying user-application and access rates, comprising: a plurality of code slice allocations collectively representing a quantity of code space contained in said transmission medium; a plurality of frequency slices in said transmission medium; means for slicing the transmission medium into a plurality of code-frequency slices; means for scheduling one or more users in at least one of said code-frequency slices in said transmission medium, wherein said means for scheduling schedules a quantity of code space based on a level of interference contributed by each user in said transmission medium, the scheduling based on a number and type of users for each of said code-frequency slices.
Claim 5
Independent Claim
123 words
A system for optimizing spectral use of a code-division-multiple-access (CDMA) transmission medium by a plurality of users of varying user-application and access rates, comprising: a plurality of code slice allocations collectively representing a quantity of code space contained in said transmission medium; a plurality of time slices in said transmission medium; means for slicing the transmission medium into a plurality of code-time slices; means for scheduling one or more users in at least one of said code-time slices in said transmission medium, wherein said means for scheduling schedules a quantity of code space based on a level of interference contributed by each user in said transmission medium, the scheduling based on a number and type of users for each of said code-time slices.
Claim 6
Independent Claim
152 words
A system for optimizing spectral use of a code-division-multiple-access (CDMA) transmission medium by a plurality of users of varying user-application and access speeds, comprising: a plurality of code slice allocations representing a quantity of code space contained in said transmission medium; a plurality of time slices in said transmission medium; means for slicing the transmission medium into a plurality of code-time slices; a set of individual codes contained within said transmission medium; means for assigning an individual code having a length to a user of said transmission medium, the length of said individual code inversely related to a quantity of code space to be occupied by said user; means for scheduling one or more users in at least one of said code-time slices in said transmission medium, wherein said means for scheduling assigns individual length codes to said users based on the code space requirements of the users in said transmission medium.
Claim 7
Dependent Claim
33 words
The system of claim 6 wherein at least one of said individual codes is reassigned to a user based on temporal occupancy of said at least one individual code in the transmission medium.
Claim 8
Independent Claim
110 words
A system for optimizing spectral use of a code-division-multiple-access (CDMA) transmission medium by a plurality of users of varying user-application and access speeds, comprising: a plurality of code slice allocations representing a quantity of code space contained in said transmission medium; a plurality of time slices in said transmission medium; a plurality of frequency slices in said transmission medium; means for slicing the transmission medium into a plurality of code-time-frequency slices; means for scheduling one or more users in at least one of said code-time-frequency slices in said transmission medium, wherein said means for scheduling schedules a quantity of code space to each of said users of the transmission medium.
Claim 9
Independent Claim
108 words
A method for optimizing spectral use of a communications transmission medium by a plurality of users of varying user-application and access rates, comprising the steps of: dividing the transmission medium into a plurality of frequency slices; dividing the transmission medium into a plurality of time slices; slicing the transmission medium into a plurality of time-frequency slices, each of the time-frequency slices occupying space at least equal to one frequency slice extending over one time slice; scheduling one or more of said users in at least one of said time-frequency slices in the transmission medium so as to optimize occupancy of the space contained within the communications transmission medium.
Claim 10
Independent Claim
140 words
A method for optimizing spectral use of a CDMA communications transmission medium by a plurality of users of varying user-application and access rates, comprising the steps of: slicing the transmission medium into a plurality of code slice allocations collectively representing a quantity of code space contained within said transmission medium; slicing the transmission medium into a plurality of time-slice allocations; slicing the transmission medium into a plurality of code-time slices, each of the code-time slices occupying space at least equal to one code slice allocation extending over one time slice allocation; and scheduling one or more of said users in at least one of said code-time slices in the transmission medium according to the amount of code space required by each of said users so as to optimize the occupancy of the code space contained within the communications transmission medium.
Claim 11
Independent Claim
140 words
A method for optimizing spectral use of a CDMA communications transmission medium by a plurality of users of varying user-application and access rates, comprising the steps of: slicing the transmission medium into a plurality of code slice allocations collectively representing a quantity of code space contained within said transmission medium; slicing the transmission medium into a plurality of frequency slice allocations; slicing the transmission medium into a plurality of code-frequency slices, each of the code-frequency slices occupying space at least equal to one code slice allocation extending over one frequency slice; and scheduling one or more of said users in at least one of said code-frequency slices in the transmission medium according to the amount of code space required by each of said users so as to optimize the occupancy of the code space contained within the communications transmission medium.
Claim 12
Independent Claim
188 words
A method for optimizing spectral use of a CDMA communications transmission medium by a plurality of users of varying user-application and access rates, comprising the steps of: slicing the transmission medium into a plurality of code slice allocations collectively representing a quantity of code space contained within said transmission medium; slicing the transmission medium into a plurality of time slices; slicing the transmission medium into a plurality of code-time slices, each of the code-time slices occupying space at least equal to one code slice allocation extending over one time slice allocation; assigning an individual user a code from a set of individual codes contained within said transmission medium, the length of said individual code inversely related to a quantity of code space to be occupied in the medium by said user; and scheduling one or more of said users in at least one of said code-time slices in the transmission medium, wherein the means for scheduling assigns an individual length code to a user based on code space requirements of a user so as to optimize the occupancy of the code space contained within the communications transmission medium.
Claim 13
Independent Claim
134 words
A method for optimizing spectral use of a code-division-multiple-access (CDMA) transmission medium by a plurality of users of varying user-application and access speeds, comprising the steps of: slicing the transmission medium into a plurality of code slice allocations representing a quantity of code space contained in said transmission medium; slicing the transmission medium into a plurality of time slices in said transmission medium; slicing the transmission medium into a plurality of frequency slices in said transmission medium; slicing the transmission medium into a plurality of code-time-frequency slices; and scheduling one or more users in at least one of said code-time-frequency slices in said transmission medium according to the amount of code space required by each of said users so as to optimize the occupancy of the code space contained within the communications transmission medium.
References Cited (Backward Citations)
EP0282028A2
Cited
WO1992006546A1
Cited
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