Method for controlling transmission power on communication channels and base station to implement the method
View Patent ↗A base station transmits blocks, in successive transmission time intervals, to radio terminals, over communication channels shared between the radio terminals comprising traffic channels and control channels associated with traffic channels, some of the transmitted blocks being positively or negatively acknowledged by the radio terminals. With regard to a radio terminal: a quality indication relative to said traffic channel is determined; a quantity relative to acknowledgements transmitted to the base station beforehand is determined; a transmission power on the traffic channel and/or the associated control channel is calculated, for the next corresponding transmission time interval, from said quality indication and said quantity relative to acknowledgements.
1. A method for controlling transmission power on communication channels in a radiocommunication system comprising at least one base station designed to transmit, in successive transmission time intervals, blocks destined for radio terminals, on communication channels shared among the radio terminals, the shared communication channels comprising traffic channels and control channels associated with traffic channels, whereby at least some of the blocks transmitted by the base station produce positive or negative acknowledgements from the radio terminals,
the method comprising the following steps in relation to a radio terminal which is capable of receiving blocks on at least one traffic channel and one control channel associated with said traffic channel, during a next corresponding transmission time interval for each channel:
determining at least one quality indication relating to said traffic channel;
determining at least one quantity relating to acknowledgements previously transmitted to the base station; and
calculating a transmission power on at least one of the traffic channel or the control channel associated with said traffic channel, for said next corresponding transmission time interval, from said quality indication relating to the traffic channel and said quantity relating to acknowledgements previously transmitted to the base station.
2. The method as claimed in claim 1 , in which the traffic channel is suitable for high-speed data transmission.
3. The method as claimed in claim 1 , in which a transmission power on the traffic channel and a transmission power on the control channel associated with said traffic channel are calculated, and in which a transmission is furthermore carried out, destined for said radio terminal, on the traffic channel and on the control channel associated with said traffic channel, at the corresponding calculated transmission power during said next corresponding transmission time interval for each channel, said transmission being implemented in a selective manner if the sum of the transmission power on the traffic channel and the transmission power on the control channel associated with said traffic channel is less than a predetermined transmission power on the next corresponding transmission time interval for each channel.
4. The method as claimed in claim 3 , in which the transmission destined for said radio terminal on the control channel associated with said traffic channel, at the corresponding calculated transmission power, during said next corresponding transmission time interval, is implemented in a selective manner moreover if the sum of the transmission power on the traffic channel and the transmission power on the control channel associated with said traffic channel is less than a predetermined transmission power over the transmission time interval immediately preceding said next corresponding transmission time interval.
5. The method as claimed in claim 4 , in which said predetermined transmission power is a power remaining in the base station following allocation of power to channels already assigned.
6. The method as claimed in claim 3 , in which the transmission power on the control channel associated with said traffic channel is calculated for said next corresponding transmission time interval, then the transmission power on said traffic channel is calculated for said next corresponding transmission time interval, the transmission power on said traffic channel being calculated to be less than or equal to the difference between the predetermined transmission power and the transmission power calculated on the control channel associated with said traffic channel.
7. The method as claimed in claim 6 , in which the determination of the quality indication relating to said traffic channel and the calculation of the transmission power on said traffic channel furthermore take account of a difference between a reference power and said difference between the predetermined transmission power and the transmission power calculated on the control channel associated with said traffic channel.
8. The method as claimed in claim 6 , in which a number of physical channels on which the traffic channel can be multiplexed is derived from the determined quality indication relating to the traffic channel, according to a predefined correspondence table, and in which the determination of the quality indication relating to said traffic channel and the calculation of the transmission power on said traffic channel for said next corresponding transmission time interval furthermore take account of a comparison between said number of physical channels on which the traffic channel can be multiplexed and a number of physical resources available in the base station for said next transmission time interval.
9. The method as claimed in claim 6 , in which the determination of at least one quantity relating to acknowledgements comprises the determination of a rate of negative acknowledgements previously transmitted to the base station by said radio terminal over an observation period, and in which the determination of the quality indication relating to said traffic channel takes account of said rate of negative acknowledgements previously transmitted to the base station by said radio terminal.
10. The method as claimed in claim 9 , in which a number of physical channels on which the traffic channel is to be multiplexed is derived from the determined quality indication relating to the traffic channel, according to a predefined correspondence table, and in which the calculated transmission power is shared more or less equally among said physical channels for said next transmission time interval corresponding to the traffic channel.
11. The method as claimed in claim 1 , in which the determination of at least one quantity relating to acknowledgements previously transmitted to the base station comprises the determination of a rate of blocks which have been subject to an acknowledgement from said mobile terminal over an observation period.
12. The method as claimed in claim 11 , in which the determination of the quality indication relating to said traffic channel takes account of said rate of blocks which have been subject to an acknowledgement from said mobile terminal over an observation period.
13. The method as claimed in claim 12 , in which the transmission power on the control channel associated with said traffic channel for the next corresponding transmission time interval is calculated by adding a margin derived from said determined quality indication to the transmission power predetermined on a pilot communication channel.
14. The method as claimed in claim 1 , in which the determination of the quality indication relating to said traffic channel takes account of quality information relating to said traffic channel transmitted to the base station by said radio terminal.
15. A base station, designed to transmit, in successive transmission time intervals, blocks destined for radio terminals, on communication channels shared among the radio terminals, the shared communication channels comprising traffic channels and control channels associated with traffic channels, at least some of the blocks transmitted by the base station producing positive or negative acknowledgements from the radio terminals,
the base station comprising, in relation to a radio terminal which is capable of receiving blocks on at least one traffic channel and one control channel associated with said traffic channel, during a next corresponding transmission time interval for each channel:
means for obtaining at least one quality indication relating to said traffic channel;
means for determining at least one quantity relating to acknowledgements previously transmitted to the base station; and
means for calculating a transmission power on at least one of the traffic channel or the control channel associated with said traffic channel, for said next corresponding transmission time interval, from said quality indication relating to the traffic channel and said quantity relating to acknowledgements previously transmitted to the base station.
16. The base station as claimed in claim 15 , in which the traffic channel is suitable for high-speed data transmission.
17. The base station as claimed in claim 15 , in which said means for calculating a transmission power are arranged for calculating a transmission power on the traffic channel and a transmission power on the control channel associated with said traffic channel, the base station further comprising means for carrying out a transmission, destined for said radio terminal, on the traffic channel and on the control channel associated with said traffic channel, at the corresponding calculated transmission power during said next corresponding transmission time interval for each channel, said transmission being implemented in a selective manner if the sum of the transmission power on the traffic channel and the transmission power on the control channel associated with said traffic channel is less than a predetermined transmission power on the next corresponding transmission time interval for each channel.
18. The base station as claimed in claim 17 , in which the transmission destined for said radio terminal on the control channel associated with said traffic channel, at the corresponding calculated transmission power, during said next corresponding transmission time interval, is implemented in a selective manner moreover if the sum of the transmission power on the traffic channel and the transmission power on the control channel associated with said traffic channel is less than a predetermined transmission power over the transmission time interval immediately preceding said next corresponding transmission time interval.
19. The base station as claimed in claim 18 , in which said predetermined transmission power is a power remaining in the base station following allocation of power to channels already assigned.
20. The base station as claimed in claim 17 , in which the means for calculating a transmission power on at least one of the traffic channel or the control channel associated with said traffic channel calculates the transmission power on the control channel associated with said traffic channel for said next corresponding transmission time interval, and then the transmission power on said traffic channel for said next corresponding transmission time interval, the transmission power on said traffic channel being calculated to be less than or equal to the difference between the predetermined transmission power and the transmission power calculated on the control channel associated with said traffic channel.
21. The base station as claimed in claim 20 , in which the means for obtaining the quality indication relating to said traffic channel and the means for calculating the transmission power on said traffic channel furthermore take account of a difference between a reference power and said difference between the predetermined transmission power and the transmission power calculated on the control channel associated with said traffic channel.
22. The base station as claimed in claim 20 , comprising means for deriving a number of physical channels on which the traffic channel can be multiplexed from the determined quality indication relating to the traffic channel, according to a predefined correspondence table, and in which the means for obtaining the quality indication relating to said traffic channel and the the means for calculating the transmission power on said traffic channel for said next corresponding transmission time interval furthermore take account of a comparison between said number of physical channels on which the traffic channel can be multiplexed and a number of physical resources available in the base station for said next transmission time interval.
23. The base station as claimed in claim 20 , in which the means for determining at least one quantity relating to acknowledgements comprises means for determining a rate of negative acknowledgements previously transmitted to the base station by said radio terminal over an observation period, and in which the means for obtaining the quality indication relating to said traffic channel takes account of said rate of negative acknowledgements previously transmitted to the base station by said radio terminal.
24. The base station as claimed in claim 23 , comprising means for deriving a number of physical channels on which the traffic channel is to be multiplexed from the determined quality indication relating to the traffic channel, according to a predefined correspondence table, and means for sharing the calculated transmission power more or less equally among said physical channels for said next transmission time interval corresponding to the traffic channel.
25. The base station as claimed in claim 18 , in which the means for determining at least one quantity relating to acknowledgements previously transmitted to the base station comprises means for determining a rate of blocks which have been subject to an acknowledgement from said mobile terminal over an observation period.
26. The base station as claimed in claim 25 , in which the means for obtaining the quality indication relating to said traffic channel takes account of said rate of blocks which have been subject to an acknowledgement from said mobile terminal over an observation period.
27. The base station as claimed in claim 26 , in which the means for calculating the transmission power on the control channel associated with said traffic channel for the next corresponding transmission time interval adds a margin derived from said determined quality indication to the transmission power predetermined on a pilot communication channel.
28. The base station as claimed in claim 15 , in which the means for obtaining the quality indication relating to said traffic channel takes account of quality information relating to said traffic channel transmitted to the base station by said radio terminal.
29. A computer program product to be installed in a base station, comprising instructions to carry out, during an execution of the program by the means of the base station, a method for controlling transmission power on communication channels in a radiocommunication system comprising at least one base station designed to transmit, in successive transmission time intervals, blocks destined for radio terminals, on communication channels shared among the radio terminals, the shared communication channels comprising traffic channels and control channels associated with traffic channels, whereby at least some of the blocks transmitted by the base station produce positive or negative acknowledgements from the radio terminals,
said instructions being arranged to carry out the following steps in relation to a radio terminal which is capable of receiving blocks on at least one traffic channel and one control channel associated with said traffic channel, during a next corresponding transmission time interval for each channel:
determining at least one quality indication relating to said traffic channel;
determining at least one quantity relating to acknowledgements previously transmitted to the base station; and
calculating a transmission power on at least one of the traffic channel or the control channel associated with said traffic channel, for said next corresponding transmission time interval, from said quality indication relating to the traffic channel and said quantity relating to acknowledgements previously transmitted to the base station.
30. The computer program product as claimed in claim 29 , in which the traffic channel is suitable for high-speed data transmission.
31. The computer program product as claimed in claim 29 , in which a transmission power on the traffic channel and a transmission power on the control channel associated with said traffic channel are calculated, and in which a transmission is furthermore carried out, destined for said radio terminal, on the traffic channel and on the control channel associated with said traffic channel, at the corresponding calculated transmission power during said next corresponding transmission time interval for each channel, said transmission being implemented in a selective manner if the sum of the transmission power on the traffic channel and the transmission power on the control channel associated with said traffic channel is less than a predetermined transmission power on the next corresponding transmission time interval for each channel.
32. The computer program product as claimed in claim 31 , in which the transmission destined for said radio terminal on the control channel associated with said traffic channel, at the corresponding calculated transmission power, during said next corresponding transmission time interval, is implemented in a selective manner moreover if the sum of the transmission power on the traffic channel and the transmission power on the control channel associated with said traffic channel is less than a predetermined transmission power over the transmission time interval immediately preceding said next corresponding transmission time interval.
33. The computer program product as claimed in claim 32 , in which said predetermined transmission power is a power remaining in the base station following allocation of power to channels already assigned.
34. The computer program product as claimed in claim 31 , in which the transmission power on the control channel associated with said traffic channel is calculated for said next corresponding transmission time interval, then the transmission power on said traffic channel is calculated for said next corresponding transmission time interval, the transmission power on said traffic channel being calculated to be less than or equal to the difference between the predetermined transmission power and the transmission power calculated on the control channel associated with said traffic channel.
35. The computer program product as claimed in claim 34 , in which the determination of the quality indication relating to said traffic channel and the calculation of the transmission power on said traffic channel furthermore take account of a difference between a reference power and said difference between the predetermined transmission power and the transmission power calculated on the control channel associated with said traffic channel.
36. The computer program product as claimed in claim 34 , in which a number of physical channels on which the traffic channel can be multiplexed is derived from the determined quality indication relating to the traffic channel, according to a predefined correspondence table, and in which the determination of the quality indication relating to said traffic channel and the calculation of the transmission power on said traffic channel for said next corresponding transmission time interval furthermore take account of a comparison between said number of physical channels on which the traffic channel can be multiplexed and a number of physical resources available in the base station for said next transmission time interval.
37. The computer program product as claimed in claim 34 , in which the determination of at least one quantity relating to acknowledgements comprises the determination of a rate of negative acknowledgements previously transmitted to the base station by said radio terminal over an observation period, and in which the determination of the quality indication relating to said traffic channel takes account of said rate of negative acknowledgements previously transmitted to the base station by said radio terminal.
38. The computer program product as claimed in claim 37 , in which a number of physical channels on which the traffic channel is to be multiplexed is derived from the determined quality indication relating to the traffic channel, according to a predefined correspondence table, and in which the calculated transmission power is shared more or less equally among said physical channels for said next transmission time interval corresponding to the traffic channel.
39. The computer program product as claimed in claim 29 , in which the determination of at least one quantity relating to acknowledgements previously transmitted to the base station comprises the determination of a rate of blocks which have been subject to an acknowledgement from said mobile terminal over an observation period.
40. The computer program product as claimed in claim 39 , in which the determination of the quality indication relating to said traffic channel takes account of said rate of blocks which have been subject to an acknowledgement from said mobile terminal over an observation period.
41. The computer program product as claimed in claim 40 , in which the transmission power on the control channel associated with said traffic channel for the next corresponding transmission time interval is calculated by adding a margin derived from said determined quality indication to the transmission power predetermined on a pilot communication channel.
42. The computer program product as claimed in claim 29 , in which the determination of the quality indication relating to said traffic channel takes account of quality information relating to said traffic channel transmitted to the base station by said radio terminal.