WO1998016029B1 - Method for improving co-channel interference in a cellular system - Google Patents
Method for improving co-channel interference in a cellular systemInfo
- Publication number
- WO1998016029B1 WO1998016029B1 PCT/US1997/017801 US9717801W WO9816029B1 WO 1998016029 B1 WO1998016029 B1 WO 1998016029B1 US 9717801 W US9717801 W US 9717801W WO 9816029 B1 WO9816029 B1 WO 9816029B1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- channel
- cells
- channels
- signal quality
- cell
- Prior art date
Links
- 230000001413 cellular Effects 0.000 title claims abstract 13
- 239000000969 carrier Substances 0.000 claims 7
- 230000000694 effects Effects 0.000 claims 4
- 230000003044 adaptive Effects 0.000 claims 2
- 230000003595 spectral Effects 0.000 abstract 3
- 230000002452 interceptive Effects 0.000 abstract 1
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.
Claims
1. A method for allocating frequencies in a cellular radio communication having 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 fractional loading scheme for selected cells so that the maximum number of channels used at any given time in the selected cells is less than the total number of available channels in the selected cells; and
(c) spacing co-channel cells in said cellular communication system to meet a pre-determined signal quality standard based on said fractional loading scheme.
2. cancelled
3. The method according to claim 1 wherein the available communication channels in the fractionally loaded cells are assigned at random.
4. 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.
5. The method according to claim 1 further including the step of establishing a threshold for the total number of simultaneous users in each cell.
23
6. The method according to claim 5 further including the step of denying access when the threshold is reached.
7. The method according to claim 5 further including the step of transmitting a test signal on an unused channel when the threshold is reached and performing a signal quality test to determine whether additional channels should be assigned.
8. The method according to claim 7 wherein said signal quality test comprises testing the signal quality on the test channel.
9. The method according to claim 7 wherein said signal quality test comprises testing the effect of the test signal on a channel already in use.
10. A cellular radio communication system 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) said plurality of cells including at least one fractionally loaded cell in which the maximum number of channels in use at any given time is less than the total number of available channels in said cells; and
(c) wherein co-channel cells in said radio communication system are spaced to meet a pre-determined signal quality standard based on said factional loading scheme.
11. The cellular radio communication system according to claim 10 wherein the assignment of communication channels in the fractionally-loaded cells is made at random.
12. The cellular communication system according to claim 10 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.
13. The cellular radio communication system according to claim 10 wherein a predetermined threshold is established for the total number of users in the fractionally-load cell which is less than the total number of the available channels.
14. The cellular radio communication system according to claim 13 wherein the assignment of communication channels to users is blocked when the predetermined threshold is reached.
15. The cellular radio communication system according to claim 13 wherein the assignment of communication channels to users once said predetermined threshold is reached is based on a signal quality test.
16. The cellular radio communication system according to claim 15 wherein the signal quality test comprises transmitting a test signal on an available channel and measuring the signal quality of the test signal.
17. The cellular radio communication system according to claim 15 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.
18. A method for increasing the number of users in a multiple beam satellite communication system having a plurality of spot beams 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
25 communication channels so that a plurality of communication channels are available in each cell;
(b) establishing a fractional loading scheme for selected spot beams so that the maximum number of channels used at any given time in the selected spot beams is less than the total number of available channels in the spot beams; and
(c) spacing the co-channel spot beams to obtain a pre-determined minimum signal quality standard based on said fractional loading scheme.
19. The method according to claim 18 wherein the available communication channels in the fractionally loaded spot beams are assigned at random.
20. The method according to claim 18 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.
21. The method according to claim 18 further including the step of establishing a threshold for the total number of simultaneous users in each spot beam.
22. The method according to claim 21 further including the step of denying access when the threshold is reached.
23. The method according to claim 21 further including the step of transmitting a test signal on an unused channel when the threshold is reached and performing a signal quality test to determine whether additional channels should be assigned.
24. The method according to claim 23 wherein said signal quality test comprises testing the signal quality on the test channel.
26
25. The method according to claim 23 wherein said signal quality test comprises testing the effect of the test signal on a channel already in use.
26. A method for reducing co-channel interference in a cellular radio, communication having a plurality of cells, comprising:
(a) allocating the available carrier frequencies within the system to said cell 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 fractional loading scheme for selected cells so that the maximum number of channels used at any given time in the selected cells is less than the total number of available channels in the selected cells; and
(c) allocating channels within each cell to users according to a predetermined adaptive allocation scheme.
27. The method of claim 27 wherein the adaptive allocation scheme includes selecting a channel within a cell based on the usage rate of that channel in all co-channel cells.
28. The method according to claim 26 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.
29. The method according to claim 26 further including the step of establishing a threshold for the total number of simultaneous users in each cell.
30. The method according to claim 29 further including the step of denying access when the threshold is reached.
27
31. The method according to claim 29 further including the step of transmitting a test signal on an unused channel when the threshold is reached and performing a signal quality test to determine whether additional channels should be assigned.
32. The method according to claim 31 wherein said signal quality test comprises testing the signal quality on the test channel.
33. The method according to claim 31 wherein said signal quality test comprises testing the effect of the test signal on a channel already in use.
28
STATEMENT UNDER ARTICLE 19
Pursuant to Article 19(1) the claims have been amended. In particular, claims 1 and 10 have been amended to include the limitation that the co-channel cells be spaced to meet a predetermined signal quality standard based on the fractional loading of the cells in the communication system. In claim 18, the reference to "minimum acceptable code to interference ratio C/l" has been changed to "minimum signal quality standard." Claim 2 has been canceled since the additional limitation set forth therein has been incorporated into amended claim 1.
29
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU46657/97A AU728686B2 (en) | 1996-10-10 | 1997-10-03 | Method for improving co-channel interference in a cellular system |
CA002268289A CA2268289A1 (en) | 1996-10-10 | 1997-10-03 | Method for improving co-channel interference in a cellular system |
DE69705737T DE69705737T2 (en) | 1996-10-10 | 1997-10-03 | METHOD FOR REDUCING INTERFERENCE BETWEEN NEXT CHANNELS IN A CELLULAR NETWORK |
EP97945455A EP0932946B1 (en) | 1996-10-10 | 1997-10-03 | Method for improving co-channel interference in a cellular system |
JP10517613A JP2001502138A (en) | 1996-10-10 | 1997-10-03 | Method for improving co-channel interference in cellular systems |
BR9712513-0A BR9712513A (en) | 1996-10-10 | 1997-10-03 | Processes to reduce co-channel interference in your cellular radio communication and increase the number of users in a multi-beam satellite communication system, and cellular radio communication system. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/728,564 | 1996-10-10 | ||
US08/728,564 US5946625A (en) | 1996-10-10 | 1996-10-10 | Method for improving co-channel interference in a cellular system |
Publications (3)
Publication Number | Publication Date |
---|---|
WO1998016029A2 WO1998016029A2 (en) | 1998-04-16 |
WO1998016029A3 WO1998016029A3 (en) | 1998-06-18 |
WO1998016029B1 true WO1998016029B1 (en) | 1998-08-06 |
Family
ID=24927364
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1997/017801 WO1998016029A2 (en) | 1996-10-10 | 1997-10-03 | Method for improving co-channel interference in a cellular system |
Country Status (10)
Country | Link |
---|---|
US (1) | US5946625A (en) |
EP (1) | EP0932946B1 (en) |
JP (1) | JP2001502138A (en) |
CN (1) | CN1118155C (en) |
AU (1) | AU728686B2 (en) |
BR (1) | BR9712513A (en) |
CA (1) | CA2268289A1 (en) |
DE (1) | DE69705737T2 (en) |
TW (1) | TW376599B (en) |
WO (1) | WO1998016029A2 (en) |
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-
1996
- 1996-10-10 US US08/728,564 patent/US5946625A/en not_active Expired - Lifetime
-
1997
- 1997-10-03 CN CN97180489A patent/CN1118155C/en not_active Expired - Fee Related
- 1997-10-03 BR BR9712513-0A patent/BR9712513A/en unknown
- 1997-10-03 WO PCT/US1997/017801 patent/WO1998016029A2/en active IP Right Grant
- 1997-10-03 JP JP10517613A patent/JP2001502138A/en active Pending
- 1997-10-03 AU AU46657/97A patent/AU728686B2/en not_active Ceased
- 1997-10-03 CA CA002268289A patent/CA2268289A1/en not_active Abandoned
- 1997-10-03 EP EP97945455A patent/EP0932946B1/en not_active Expired - Lifetime
- 1997-10-03 DE DE69705737T patent/DE69705737T2/en not_active Expired - Lifetime
- 1997-10-08 TW TW086114748A patent/TW376599B/en active
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