US6708041B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Base station transmit power control in a CDMA cellular telephone system
Assignee: Telefonaktiebolaget LM Ericsson AB
•
Filing: 1998-11-10
•
Granted: 2004-03-16
•
Expires: 2018-11-10
Abstract
Abstract A power control method in accordance with the present invention synchronizes the transmit power levels at the base stations currently serving a mobile station and an initial transmit power level of a new target base station being added in a diversity handover situation. At the beginning of the handover, a radio network controller orders the serving base stations to measure their respective transmit powers to the mobile station. Each serving base station then measures its transmit power to the mobile station and reports the power level measurements to the radio network controller. An initial transmit power setting is determined for the target base station, and new transmit power settings are determined for the serving base stations synchronized for example to a particular time (t0). At or about synchronizing time t0, the target base station transmits to the mobile station at the initial power setting, and at or about the same time, the serving base stations preferably also adjust their transmit powers toward the new values. Alternatively, the serving base stations transmit at their respective new values at or about time t0. In a preferred embodiment of the present invention, the serving base station power adjustment is performed gradually.
Inventors
- 👤 Peter Butovitsch
- 👤 Peter B. Andersson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:02
CPC Classifications
H; H04; H04W; H04W52/00; H04W52/04; H04W52/38; H04W52/40; H04W36/00; H04W36/08; H04W52/50
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
169 words
A power control method for a mobile radio communications system including a controller connected to plural base stations, each base station communicating with mobile stations located within or near a geographical area associated with the base station, comprising: for a call involving a mobile station, establishing an initial communication between the mobile station and a first base station with the first base station transmitting call traffic to the mobile station at a transmit power level over a first traffic channel; for the same call, establishing a diversity handover communication between the mobile station and a second base station over a second traffic channel in addition to the initial communication; determining an initial transmit power level for the second base station for the diversity handover communication transmissions from the second base station to the mobile station over the second traffic channel; and controlling the transmit power level of one of the first and second base stations to achieve a desired transmit power offset between the first and second power levels.
Claim 2
Dependent Claim
169 words
A power control method for a mobile radio communications system including a controller connected to plural base stations, each base station communicating with mobile stations located within or near a geographical area associated with the base station, comprising: for a call involving a mobile station, establishing an initial communication between the mobile station and a first base station with the first base station transmitting call traffic to the mobile station at a transmit power level over a first traffic channel; for the same call, establishing a diversity handover communication between the mobile station and a second base station over a second traffic channel in addition to the initial communication; determining an initial transmit power level for the second base station for the diversity handover communication transmissions from the second base station to the mobile station over the second traffic channel; and controlling the transmit power level of one of the first and second base stations to achieve a desired transmit power offset between the first and second power levels.
Claim 3
Dependent Claim
12 words
The method in claim 1 , wherein the desired offset is zero.
Claim 4
Dependent Claim
12 words
The method in claim 1 , wherein the desired offset is non-zero.
Claim 5
Dependent Claim
50 words
The method in claim 1 , wherein signals received by the first and second base stations from the mobile station are diversity-combined in the controller and the signals received by the mobile station from the first and second base stations are diversity-combined in a RAKE receiver in the mobile station.
Claim 6
Dependent Claim
38 words
The method in claim 1 , the controlling step further comprising: gradually changing the transmit power level of one of the first and second base stations to reduce the difference between the first and second transmit power levels.
Claim 7
Dependent Claim
28 words
The method in claim 1 , wherein the controlling step includes: adjusting the transmit power levels of the first and second base stations to the same power level.
Claim 8
Dependent Claim
49 words
The method in claim 1 , wherein the determining step further includes: establishing a predetermined time associated with a desired transmit power level for the first base station over the first traffic channel and the initial transmit power level of the second base station over the second traffic channel.
Claim 9
Dependent Claim
45 words
The method in claim 7 , the controlling step further comprising: determining a difference between an actual transmit power level of the first base station at time t 0 and the desired transmit power level of the first base station at time t 0 .
Claim 10
Dependent Claim
79 words
The method in claim 8 , wherein if the difference exceeds a threshold, the controlling step further comprising: comparing the actual and desired transmit power levels of the first base station; if the actual transmit power level exceeds the desired transmit power level of the first base station, decreasing the power level; and if the actual transmit power level is less than or equal to the desired transmit power level of the first base station, increasing the power level.
Claim 11
Dependent Claim
37 words
The method in claim 9 , wherein the transmit power level of the first base station is changed incrementally with a first delay period between each incremental increase and a second delay period between each incremental decrease.
Claim 12
Dependent Claim
54 words
The method in claim 1 , further comprising after the second base station is transmitting: determining whether an undesired transmit power level offset exists between the first and second base station, and controlling the transmit power level of one of the first and second base stations to reduce the undesired transmit power level offset.
Claim 13
Dependent Claim
140 words
Apparatus for use in a mobile communications system, comprising: a first base station for establishing a communication with a mobile station with the first base station transmitting to the mobile station at a transmit power level over a first traffic channel; a second base station for establishing a handover communication with the mobile station over a second traffic channel; and a base station controller, coupled to the first and second base stations, for setting an initial power level for the second base station to transmit to the mobile station for the handover communication over the second traffic channel and adjusting the transmit power level of the first base station to the mobile station over the first traffic channel in conjunction with setting the initial power level of the second base station for the handover communication over the second traffic channel.
Claim 14
Dependent Claim
140 words
Apparatus for use in a mobile communications system, comprising: a first base station for establishing a communication with a mobile station with the first base station transmitting to the mobile station at a transmit power level over a first traffic channel; a second base station for establishing a handover communication with the mobile station over a second traffic channel; and a base station controller, coupled to the first and second base stations, for setting an initial power level for the second base station to transmit to the mobile station for the handover communication over the second traffic channel and adjusting the transmit power level of the first base station to the mobile station over the first traffic channel in conjunction with setting the initial power level of the second base station for the handover communication over the second traffic channel.
Claim 15
Dependent Claim
36 words
The apparatus in claim 12 , wherein the base station controller includes a diversity handover unit for diversity combining signals corresponding to a communication from the mobile station received from the first and second base stations.
Claim 16
Dependent Claim
30 words
The apparatus in claim 12 , wherein the transmit power level of the first base station may be adjusted towards the set initial power level of the second base station.
Claim 17
Dependent Claim
33 words
The apparatus in claim 12 , wherein the transmit power level of the first base station is adjusted to a desired offset from the set initial power level of the second base station.
Claim 18
Dependent Claim
33 words
The apparatus in claim 12 , wherein the first and second base stations each include a transmit power controller for varying the transmit power level of the base station to the mobile station.
Claim 19
Dependent Claim
41 words
The apparatus in claim 16 , wherein one of the first and second base station transmit power controllers is configured to vary its base station transmit power in response to a transmit power level control signal from the base station controller.
Claim 20
Dependent Claim
80 words
The apparatus in claim 12 , wherein the mobile station includes: a RAKE receiver for diversity combining the signals received by the mobile station from the first and second base stations to generate a diversity combined received signal, and a mobile station controller for measuring a parameter of the diversity combined received signal and transmitting to the first and second base stations a transmit power level control command to increase or decrease the transmit power based on the measured parameter.
Claim 21
Dependent Claim
35 words
The apparatus in claim 12 , wherein the transmit power level of the first base station is adjustable to reduce a difference between the initial second transmit power level and the first transmit power level.
Claim 22
Dependent Claim
29 words
The apparatus in claim 12 , wherein the base station controller is configured to gradually change the transmit power level of one of the first and second base stations.
Claim 23
Dependent Claim
47 words
The apparatus in claim 12 , wherein the base station controller is configured to establish a predetermined synchronization time for the handover communication associated with desired transmit power levels for the first base station and the second base station over the first and second traffic channels, respectively.
Claim 24
Dependent Claim
63 words
The apparatus in claim 21 , wherein the first base station is configured to determine a difference between an actual transmit power level of the first base station at synchronization time and a desired transmit power level of the first base station at synchronization time and adjust the first base station transmit power level over the first traffic channel to decrease the difference.
Claim 25
Independent Claim
115 words
A method comprising coordinating a transmit power level of a serving base station transmitting to a mobile station over a first traffic channel with an initial transmit power level of a target base station transmitting to the mobile station in a diversity handover operation over a second traffic channel, wherein a new transmit power level is determined for the serving base station transmitting to the mobile station over the first traffic channel based on the initial power level of the target base station over the second traffic channel, and the initial and new transmit power levels are provided to the serving and target base stations with a predetermined synchronization time associated with the handover operation.
Claim 26
Independent Claim
115 words
A method comprising coordinating a transmit power level of a serving base station transmitting to a mobile station over a first traffic channel with an initial transmit power level of a target base station transmitting to the mobile station in a diversity handover operation over a second traffic channel, wherein a new transmit power level is determined for the serving base station transmitting to the mobile station over the first traffic channel based on the initial power level of the target base station over the second traffic channel, and the initial and new transmit power levels are provided to the serving and target base stations with a predetermined synchronization time associated with the handover operation.
Claim 27
Dependent Claim
16 words
The method in claim 23 applied to a code division multiple access (CDMA) mobile communications system.
Claim 28
Dependent Claim
36 words
The method in claim 23 including coordinating respective transmit power levels of plural serving base stations supporting a soft handover communication with the mobile station with the initial transmit power level of the target base station.
Claim 29
Dependent Claim
39 words
The method in claim 23 , further comprising adjusting the transmit power level at the serving base station to reduce a difference between an actual transmit power level at the predetermined synchronization time and the new transmit power level.
Claim 30
Dependent Claim
12 words
The method in claim 26 , wherein the reduction is performed gradually.
Claim 31
Dependent Claim
46 words
The method in claim 23 , further comprising adjusting the transmit power level at one or both of the serving and target base stations to reduce a difference between an actual transmit power level at the predetermined time and the new or initial transmit power level.
Claim 32
Dependent Claim
173 words
A power control method for a mobile radio communications system including a controller connected to plural base stations, each base station communicating with mobile stations located within or near a geographical area associated with the base station and having plural sectors each having one or more antennas, comprising: for a call involving a mobile station, establishing an initial communication between the mobile station and a first sector with the first sector transmitting call traffic to the mobile station at a transmit power level over a first traffic channel; for the same call, establishing a diversity handover communication between the mobile station and a second sector over a second traffic channel in addition to the initial communication; determining an initial transmit power level for the second sector for the diversity handover communication transmissions from the second sector to the mobile station over the second traffic channel; and controlling the transmit power level of one of the first and second sectors to achieve a desired transmit power offset between the first and second power levels.
Claim 33
Dependent Claim
173 words
A power control method for a mobile radio communications system including a controller connected to plural base stations, each base station communicating with mobile stations located within or near a geographical area associated with the base station and having plural sectors each having one or more antennas, comprising: for a call involving a mobile station, establishing an initial communication between the mobile station and a first sector with the first sector transmitting call traffic to the mobile station at a transmit power level over a first traffic channel; for the same call, establishing a diversity handover communication between the mobile station and a second sector over a second traffic channel in addition to the initial communication; determining an initial transmit power level for the second sector for the diversity handover communication transmissions from the second sector to the mobile station over the second traffic channel; and controlling the transmit power level of one of the first and second sectors to achieve a desired transmit power offset between the first and second power levels.
Claim 34
Dependent Claim
13 words
The method in claim 29 , wherein the desired offset is approximately zero.
Claim 35
Dependent Claim
37 words
The method in claim 29 , the controlling step further comprising: gradually changing the transmit power level of one of the first and second sectors to reduce the difference between the first and second transmit power levels.
Claim 36
Dependent Claim
27 words
The method in claim 29 , wherein the controlling step includes: adjusting the transmit power levels of the first and second sectors to the same power level.
Claim 37
Dependent Claim
50 words
The method in claim 29 , wherein the determining step further includes: establishing a predetermined time (t 0 ) associated with a desired transmit power levels for the first sector over the first traffic channel and the initial transmit power level of the second sector over the second traffic channel.
Claim 38
Dependent Claim
43 words
The method in claim 33 , the controlling step further comprising: determining a difference between an actual transmit power level of the first sector at time t 0 and the desired transmit power level of the first sector at time t 0 .
Claim 39
Dependent Claim
83 words
The method in claim 34 , wherein if the difference exceeds a threshold, the controlling step further comprising: comparing the and desired transmit power levels of the first sector; if the actual transmit power level exceeds the desired transmit power level of the first sector, decreasing the power level of the first sector; and if the actual transmit power level is less than or equal to the desired transmit power level of the first sector, increasing the power level of the first sector.
References Cited (Backward Citations)
US4485486A
Cited
US5267262A
Cited
US5109390A
Cited
US5056109A
Cited
US5107487A
Cited
US5305468A
Cited
US5430760A
Cited
US5574982A
Cited
US5684793A
Cited
US5652748A
Cited
US5487180A
Cited
US5799004A
Cited
US5491837A
Cited
EP0680160A2
Cited
EP0682419A2
Cited
US5809430A
Cited
US5551057A
Cited
US5862489A
Cited
US5884176A
Cited
US5722044A
Cited
US5604730A
Cited
WO1996008119A2
Cited
US5710974A
Cited
US5671221A
Cited
US5710982A
Cited
WO1997002665A2
Cited
US5839056A
Cited
US5715526A
Cited
WO1997026716A2
Cited
US5884187A
Cited
US6070084A
Cited
US5864578A
Cited
US5799005A
Cited
EP0809365A1
Cited
US6034635A
Cited
US6128493A
Cited
US5893035A
Cited
US6163696A
Cited
US6073025A
Cited
US6097947A
Cited
US6151512A
Cited
US5940743A
Cited
WO1998056120A2
Cited
US6173162B1
Cited
WO1999008398A2
Cited
US5926503A
Cited
US6038450A
Cited
WO1999031819A1
Cited
US6085108A
Cited
US6078813A
Cited
US6175745B1
Cited
EP0940930A2
Cited
WO1999052310A2
Cited
US6144861A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-03-16 | 2007-09-15 | 2008-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-03-16 | 2011-09-15 | 2012-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-03-16 | 2015-09-15 | 2016-03-16 | $7700.00 | Window Closed / Lapsed |