US5946625A
Expired / Lapsed
US
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Method for improving co-channel interference in a cellular system
Assignee: Ericsson Inc
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Filing: 1996-10-10
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Granted: 1999-08-31
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Expires: 2016-10-10
Abstract
Abstract A fractional loading scheme is used to improve the spectral efficiency of a cellular system, and therefore increase the number of users that the system can support. The fractional loading scheme allows only a fraction of the total number of available communication channels within each cell to be used simultaneously. Thus, each cell is deliberately underloaded to operate at less than its full capacity. The underloading of the individual cells reduces the spectral efficiency within each cell. However, the underloading of each cell means that there will be fewer interfering users at any given time so that the co-channel interference is reduced. This reduction in co-channel interference allows the reuse distance between co-channel cells to be reduced thereby increasing the reuse of frequencies throughout the system resulting in an increase in spectral efficiency in the system as a whole.
Inventors
- 👤 Amer Hassan
- 👤 Stanley L. Reinhold
- 👤 Rajaram Ramesh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:55
CPC Classifications
H; H04; H04W; H04W16/00; H04W16/02; H04W16/12; H04B; H04B7/00; H04B7/24; H04B7/26; H04B7/2621
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
117 words
A method for improving spectral efficiency in a cellular radio communication system having a fixed frequency allocation plan and a plurality of cells, comprising: (a) allocating the available carrier frequencies within the system to said cells with each carrier frequency providing one or more distinct communication channels so that a plurality of communication channels are available in each cell; (b) establishing a pre-determined fractional load for selected cells, said pre-determined fractional load being less than the maximum number of available communication channels allocated to said cell; and (c) spacing co-channel cells in said cellular communication system in a predetermined manner to meet a pre-determined signal quality standard based on said pre-determined fractional load for said selected cells.
Claim 2
Independent Claim
117 words
A method for improving spectral efficiency in a cellular radio communication system having a fixed frequency allocation plan and a plurality of cells, comprising: (a) allocating the available carrier frequencies within the system to said cells with each carrier frequency providing one or more distinct communication channels so that a plurality of communication channels are available in each cell; (b) establishing a pre-determined fractional load for selected cells, said pre-determined fractional load being less than the maximum number of available communication channels allocated to said cell; and (c) spacing co-channel cells in said cellular communication system in a predetermined manner to meet a pre-determined signal quality standard based on said pre-determined fractional load for said selected cells.
Claim 3
Dependent Claim
20 words
The method according to claim 1 wherein the available communication channels in the fractionally loaded cells are assigned at random.
Claim 4
Dependent Claim
32 words
The method according to claim 1 wherein the assignment of communication channels in the fractionally loaded cells is made to minimize the simultaneous use of the communication channel in all co-channel cells.
Claim 5
Dependent Claim
24 words
The method according to claim 1 further including the step of denying access when the predetermined fractional load is reached in the selected cells.
Claim 6
Dependent Claim
44 words
The method according to claim 1 further including the step of transmitting a test signal on an unused channel when the predetermined fractional load is reached in the selected cells and performing a signal quality test to determine whether additional channels should be assigned.
Claim 7
Dependent Claim
20 words
The method according to claim 5 wherein said signal quality test comprises testing the signal quality on the test channel.
Claim 8
Dependent Claim
25 words
The method according to claim 5 wherein said signal quality test comprises testing the effect of the test signal on a channel already in use.
Claim 9
Dependent Claim
93 words
A cellular radio communication system having a fixed frequency allocation scheme, comprising: (a) a plurality of cells, each cell being assigned one or more carrier frequencies which provide a plurality of distinct communication channels in each cell; (b) wherein selected cells are assigned a predetermined fractional load which is less than all of the available channels in said selected cells; and (c) wherein co-channel cells in said radio communication system are spaced in a predetermined manner to meet a pre-determined signal quality standard based on said predetermined fractional load in said selected cells.
Claim 10
Dependent Claim
93 words
A cellular radio communication system having a fixed frequency allocation scheme, comprising: (a) a plurality of cells, each cell being assigned one or more carrier frequencies which provide a plurality of distinct communication channels in each cell; (b) wherein selected cells are assigned a predetermined fractional load which is less than all of the available channels in said selected cells; and (c) wherein co-channel cells in said radio communication system are spaced in a predetermined manner to meet a pre-determined signal quality standard based on said predetermined fractional load in said selected cells.
Claim 11
Dependent Claim
23 words
The cellular radio communication system according to claim 8 wherein the assignment of communication channels in the fractionally-loaded cells is made at random.
Claim 12
Dependent Claim
33 words
The cellular communication system according to claim 8 wherein the assignment of communication channels in the fractionally-loaded cells is made to minimize the simultaneous use of the communication channels in all co-channel cells.
Claim 13
Dependent Claim
30 words
The cellular radio communication system according to claim 8 wherein the assignment of communication channels to users is blocked when the predetermined fractional load is reached in the selected cells.
Claim 14
Dependent Claim
35 words
The cellular radio communication system according to claim 8 wherein the assignment of communication channels to users once said predetermined fractional load is reached in said selected cells is based on a signal quality test.
Claim 15
Dependent Claim
32 words
The cellular radio communication system according to claim 12 wherein the signal quality test comprises transmitting a test signal on an available channel and measuring the signal quality of the test signal.
Claim 16
Dependent Claim
42 words
The cellular radio communication system according to claim 12 wherein the signal quality test comprises transmitting a test signal on an available channel and measuring the effect of the test signal on other user's assigned the same channel in other co-channel cells.
Claim 17
Independent Claim
139 words
A method for increasing the number of users in a multiple beam satellite communication system having a plurality of spot beams and a fixed frequency allocation scheme, comprising the steps of: (a) assigning the available carrier frequencies within the system to said spot beams with each carrier frequency providing one or more distinct communication channels so that a plurality of communication channels are available in each cell; (b) setting a pre-determined fractional load for selected spot beams, said predetermined fractional load being less than the maximum number of said communication channels allocated to said spot beam; and (c) spacing the co-channel spot beams in a predetermined manner to obtain a pre-determined minimum signal quality standard based on the assumption that the maximum number of communication channels operating within said selected spot beams does not exceed said pre-determined fractional load.
Claim 18
Independent Claim
139 words
A method for increasing the number of users in a multiple beam satellite communication system having a plurality of spot beams and a fixed frequency allocation scheme, comprising the steps of: (a) assigning the available carrier frequencies within the system to said spot beams with each carrier frequency providing one or more distinct communication channels so that a plurality of communication channels are available in each cell; (b) setting a pre-determined fractional load for selected spot beams, said predetermined fractional load being less than the maximum number of said communication channels allocated to said spot beam; and (c) spacing the co-channel spot beams in a predetermined manner to obtain a pre-determined minimum signal quality standard based on the assumption that the maximum number of communication channels operating within said selected spot beams does not exceed said pre-determined fractional load.
Claim 19
Dependent Claim
21 words
The method according to claim 15 wherein the available communication channels in the fractionally loaded spot beams are assigned at random.
Claim 20
Dependent Claim
34 words
The method according to claim 15 wherein the assignment of communication channels in the fractionally loaded spot beams is made to minimize the simultaneous use of the communication channel in all co-channel spot beams.
Claim 21
Dependent Claim
24 words
The method according to claim 15 further including the step of denying access when the predetermined fractional load is reached in the selected cells.
Claim 22
Dependent Claim
44 words
The method according to claim 15 further including the step of transmitting a test signal on an unused channel when the predetermined fractional load is reached in the selected cells and performing a signal quality test to determine whether additional channels should be assigned.
Claim 23
Dependent Claim
20 words
The method according to claim 19 wherein said signal quality test comprises testing the signal quality on the test channel.
Claim 24
Dependent Claim
25 words
The method according to claim 19 wherein said signal quality test comprise testing the effect of the test signal on a channel already in use.
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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) | 2002-08-30 | 2003-03-01 | 2003-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-30 | 2007-03-01 | 2007-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-30 | 2011-03-01 | 2011-08-31 | $7700.00 | Window Closed / Lapsed |