EP0682418A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Transmission power control for mobile radio
Assignee: NTT Docomo Inc
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Filing: 1995-05-12
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Granted: —
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Expires: 2015-05-12
Abstract
Abstract A transmission power control method for a CDMA system including the steps of calculating an actual SIR (Signal-to-Interference Ratio) of a desired signal; deciding whether the actual SIR is greater than a predetermined reference SIR which satisfies a predetermined communication quality; forming a transmission power control bit on the basis of a result of deciding; inserting the transmission power control bit periodically into a forward frame, which steps are performed at the base station, and steps of calculating tentative reverse transmission power in accordance with the transmission power control bit in the forward frame; deciding reverse transmission power such that the reverse transmission power is made equal to the tentative reverse transmission power when the tentative reverse transmission power is less than a predetermined maximum transmission power, but otherwise made equal to the predetermined maximum transmission power; and transmitting a signal from the mobile station to the base station at the reverse transmission power, which steps are performed at the mobile station. This makes it possible to prevent the transmission power from diverging to the maximum output of a transmitter power amplifier.
Inventors
- 👤 Mamoru Sawahashi
- 👤 Narumi Umeda
- 👤 Tomohiro Ntt Tomioka Daiichi Dohi
- 👤 Koji NTT Tomioka-shataku 8-502 Ohno
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 04:39
CPC Classifications
H; H04; H04W; H04W52/00; H04W52/04; H04W52/06; H04W52/14; H04W52/146; H04W52/18; H04W52/24; H04W52/241; H04W52/248; H04W52/30; H04W52/34; H04W52/343; H04W52/36; H04W52/367; H04W52/54
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
254 words
A transmission power control method for a CDMA (Code Division Multiple Access) system characterized by comprising the steps of: calculating, at a base station, a first actual SIR (Signal-to-Interference Ratio), said first actual SIR being defined as a ratio of received power of a desired signal sent from a mobile station with which the base station is communicating to a sum of interference power and thermal noise power from other stations; deciding, at the base station, whether said first actual SIR is greater than a first predetermined reference SIR which satisfies a predetermined communication quality; forming, at the base station, one or more first transmission power control bits on the basis of a result of said step of deciding; inserting, at the base station, said first transmission power control bits periodically into a forward (from base station to mobile station) frame; calculating, at said mobile station, tentative reverse (mobile station to base station) transmission power in accordance with said first transmission power control bits in said forward frame sent from said base station; deciding, at the mobile station, reverse transmission power, said reverse transmission power being made equal to said tentative reverse transmission power when said tentative reverse transmission power is equal to or less than first predetermined maximum transmission power, and being made equal to said first predetermined maximum transmission power when said tentative reverse transmission power is greater than said first predetermined maximum transmission power; and transmitting a signal from said mobile station to said base station at said reverse transmission power.
Claim 2
Dependent Claim
49 words
The transmission power control method as claimed in claim 1, characterized in that said first predetermined maximum transmission power is determined on the basis of a maximum capacity in terms of number of subscribers in a cell, a radius of the cell, and an outage probability of the cell.
Claim 3
Dependent Claim
245 words
A transmission power control method for a CDMA (Code Division Multiple Access) system characterized by comprising the steps of: calculating, at a mobile station, an actual SIR (Signal-to-Interference Ratio), said actual SIR being defined as a ratio of received power of a desired signal sent from a base station with which the mobile station is communicating to a sum of interference power and thermal noise power from other stations; deciding, at the mobile station, whether said actual SIR is greater than a predetermined reference SIR which satisfies a predetermined communication quality; forming, at the mobile station, one or more transmission power control bits on the basis of a result of said step of deciding; inserting, at the mobile station, said transmission power control bits periodically into a reverse (from mobile station to base station) frame; calculating, at said base station, tentative forward (base station to mobile station) transmission power in accordance with said transmission power control bits in said reverse frame sent from said mobile station; deciding, at the base station, forward transmission power, said forward transmission power being made equal to said tentative forward transmission power when said tentative forward transmission power is equal to or less than a predetermined maximum transmission power, and being made equal to said predetermined maximum transmission power when said tentative forward transmission power is greater than said predetermined maximum transmission power; and transmitting a signal from said base station to said mobile station at said forward transmission power.
Claim 4
Dependent Claim
48 words
The transmission power control method as claimed in claim 3, characterized in that said predetermined maximum transmission power is determined on the basis of a maximum capacity in terms of number of subscribers in a cell, a radius of the cell, and an outage probability of the cell.
Claim 5
Dependent Claim
252 words
The transmission power control method as claimed in claim 1, further characterized by comprising the steps of: calculating, at the mobile station, a second actual SIR (Signal-to-Interference Ratio), said second actual SIR being defined as a ratio of received power of a desired signal sent from the base station with which the mobile station is communicating to a sum of interference power and thermal noise power from other stations; deciding, at the mobile station, whether said second actual SIR is greater than a second predetermined reference SIR which satisfies a predetermined communication quality; forming, at the mobile station, one or more second transmission power control bits on the basis of a result of said step of deciding; inserting, at the mobile station, said second transmission power control bits periodically into a reverse (from mobile station to base station) frame; calculating, at said base station, tentative forward (base station to mobile station) transmission power in accordance with said second transmission power control bits in said reverse frame sent from said mobile station; deciding, at the base station, forward transmission power, said forward transmission power being made equal to said tentative forward transmission power when said tentative forward transmission power is equal to or less than second predetermined maximum transmission power, and being made equal to said second predetermined maximum transmission power when said tentative forward transmission power is greater than said second predetermined maximum transmission power; and transmitting a signal from said base station to said mobile station at said forward transmission power.
Claim 6
Dependent Claim
266 words
A transmission power control apparatus for a CDMA (Code Division Multiple Access) system characterized by comprising: means for calculating, at a base station, a first actual SIR (Signal-to-Interference Ratio), said first actual SIR being defined as a ratio of received power of a desired signal sent from a mobile station with which the base station is communicating to a sum of interference power and thermal noise power from other stations; means for deciding, at the base station, whether said first actual SIR is greater than a first predetermined reference SIR which satisfies a predetermined communication quality; means for forming, at the base station, one or more first transmission power control bits on the basis of a result obtained by said means for deciding; means for inserting, at the base station, said first transmission power control bits periodically into a forward (from base station to mobile station) frame; means for calculating, at said mobile station, tentative reverse (mobile station to base station) transmission power in accordance with said first transmission power control bits in said forward frame sent from said base station; means for deciding, at the mobile station, reverse transmission power, said reverse transmission power being made equal to said tentative reverse transmission power when said tentative reverse transmission power is equal to or less than first predetermined maximum transmission power, and being made equal to said first predetermined maximum transmission power when said tentative reverse transmission power is greater than said first predetermined maximum transmission power; and means for transmitting a signal from said mobile station to said base station at said reverse transmission power.
Claim 7
Dependent Claim
49 words
The transmission power control apparatus as claimed in claim 6, characterized in that said first predetermined maximum transmission power is determined on the basis of a maximum capacity in terms of number of subscribers in a cell, a radius of the cell, and an outage probability of the cell.
Claim 8
Dependent Claim
257 words
A transmission power control apparatus for a CDMA (Code Division Multiple Access) system characterized by comprising; means for calculating, at a mobile station, an actual SIR (Signal-to-Interference Ratio), said actual SIR being defined as a ratio of received power of a desired signal sent from a base station with which the mobile station is communicating to a sum of interference power and thermal noise power from other stations; means for deciding, at the mobile station, whether said actual SIR is greater than a predetermined reference SIR which satisfies a predetermined communication quality; means for forming, at the mobile station, one or more transmission power control bits on the basis of a result obtained by said means for deciding; means for inserting, at the mobile station, said transmission power control bits periodically into a reverse (from mobile station to base station) frame; means for calculating, at said base station, tentative forward (base station to mobile station) transmission power in accordance with said transmission power control bits in said reverse frame sent from said mobile station; means for deciding, at the base station, forward transmission power, said forward transmission power being made equal to said tentative forward transmission power when said tentative forward transmission power is equal to or less than a predetermined maximum transmission power, and being made equal to said predetermined maximum transmission power when said tentative forward transmission power is greater than said predetermined maximum transmission power; and means for transmitting a signal from said base station to said mobile station at said forward transmission power.
Claim 9
Dependent Claim
48 words
The transmission power control apparatus as claimed in claim 8, characterized in that said predetermined maximum transmission power is determined on the basis of a maximum capacity in terms of number of subscribers in a cell, a radius of the cell, and an outage probability of the cell.
Claim 10
Dependent Claim
264 words
The transmission power control apparatus as claimed in claim 6, further characterized by comprising: means for calculating, at the mobile station, a second actual SIR (Signal-to-Interference Ratio), said second actual SIR being defined as a ratio of received power of a desired signal sent from the base station with which the mobile station is communicating to a sum of interference power and thermal noise power from other stations; means for deciding, at the mobile station, whether said second actual SIR is greater than a second predetermined reference SIR which satisfies a predetermined communication quality; means for forming, at the mobile station, one or more second transmission power control bits on the basis of a result obtained by said means for deciding; means for inserting, at the mobile station, said second transmission power control bits periodically into a reverse (from mobile station to base station) frame; means for calculating, at said base station, tentative forward (base station to mobile station) transmission power in accordance with said second transmission power control bits in said reverse frame sent from said mobile station; means for deciding, at the base station, forward transmission power, said forward transmission power being made equal to said tentative forward transmission power when said tentative forward transmission power is equal to or less than second predetermined maximum transmission power, and being made equal to said second predetermined maximum transmission power when said tentative forward transmission power is greater than said second predetermined maximum transmission power; and means for transmitting a signal from said base station to said mobile station at said forward transmission power.
Claim 11
Independent Claim
56 words
A method or apparatus for transmission power control in a cellular CDMA communications system wherein a first station responds to receive signal characteristics by providing transmission power control signals, to which a second station may respond by increasing its own transmission power level, subject to a periodically calculated maximum transmission power level of the second station.
Claim 12
Independent Claim
34 words
A method or apparatus according to any preceding claim, wherein the or each predetermined maximum transmission power is re-calculated on the basis of at least one time varying property of a base station cell.
Claim 13
Independent Claim
20 words
A method or apparatus according to any preceding claim, wherein the or each predetermined maximum transmission power is periodically re-calculated.
Claim 14
Independent Claim
25 words
A method or apparatus according to any preceding claim, wherein the or each predetermined maximum transmission power is re-calculated for communications in a new cell.
Claim 15
Independent Claim
27 words
A method or apparatus according to any preceding claim, wherein the or each predetermined maximum transmission power is less than the maximum transmission power of the station.
Claim 16
Dependent Claim
26 words
A base station for use in a CDMA system, having the base station technical features of an apparatus according to any of claims 6 to 14.
Claim 17
Dependent Claim
26 words
A mobile station for use in a CDMA system, having the mobile station technical features of an apparatus according to any of claims 6 to 14.
References Cited (Backward Citations)
No citation records indexed.
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