Transmission power control method, mobile phone, base station, and recording medium

• US 6,343,218 B1
• Filed: 09/16/1999
• Issued: 01/29/2002
• Est. Priority Date: 01/16/1998
• Status: Expired due to Term

• Current Assignee: NTT Mobile Communications Network Inc. (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Kaneda, Ryusuke, Higashi, Akihiro, Hagiwara, Seiji
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): Green, Miguel D.
• Application Number:
  US09/381,221
• Time in Patent Office: 866 Days
• Field of Search: 455/522, 455/442, 455/436, 455/437, 455/438, 455/439, 370/335, 370/342
• US Class Current: 455/522
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

A mobile station according to the present invention that is capable of connecting simultaneously to a plurality of base stations comprises a reception radio portion and TPC bit detecting portions, for receiving and detecting TPC bits (transmission power control signals) from the plurality of base stations during soft handover; a combining portion, for combining the detected TPC bits to determine a combination signal; and a transmission power control deciding portion, for controlling the transmission power of the mobile station based on the combination signal determined by the combining portion. A method according to the present invention governs use of the mobile station hereof.

Claims

1. A transmission power control method for a mobile station simultaneously connected to a plurality of base stations, comprising:

a receiving step for receiving a transmission power control signal from each of said plurality of base stations in said mobile station;

a reliability level acquiring step for acquiring a reliability level for each of said plurality of base stations;

an object signal acquiring step for determining an object signal from said reliability level acquired in said reliability level acquiring step and said plurality of transmission power control signals received in said receiving step;

a control content deciding step for deciding a control content of the transmission power of said mobile station based on said object signal determined in said object signal acquiring step; and

a control step for controlling the transmission power of said mobile station in accordance with the control content decided in said control content deciding step.

2. A transmission power control method according to claim 1, wherein said reliability level acquiring step includes, in said mobile station, acquiring a parameter based on a downward signal from each of said plurality of base stations, and generating a reliability level with respect to each of said plurality of base stations in accordance with said parameter.

3. A transmission power control method according to claim 1, wherein said reliability level acquiring step includes, in each of said plurality of base stations, acquiring a parameter based on an upward signal from said mobile station, and sending said parameter to said mobile station;

and in said mobile station, generating a reliability level with respect to each of said plurality of base stations in accordance with the parameter sent from each of said plurality of base stations.

4. A transmission power control method according to claim 1, wherein said reliability level acquiring step includes, in each of said plurality of base stations, acquiring a parameter based on an upward signal from said mobile station, generating a reliability level for itself based on said parameter, and transmitting the generated reliability level to said mobile station;

and in said mobile station, receiving the reliability level sent from each of said plurality of base stations.

5. A transmission power control method according to claim 1, comprising:

a weighting step for weighting the transmission power control signals received in said receiving step according to said plurality of reliability levels acquired in said reliability level acquiring step;

wherein said object signal acquiring step includes generating said object signal by combining the plurality of transmission power control signals weighted in said weighting step.

6. A transmission power control method according to claim 2, comprising:

a weighting step for weighting the transmission power control signals received in said receiving step according to said plurality of reliability levels acquired in said reliability level acquiring step;

wherein said object signal acquiring step includes generating said object signal by combining the plurality of transmission power control signals weighted in said weighting step.

7. A transmission power control method according to claim 3, comprising:

a weighting step for weighting the transmission power control signals received in said receiving step according to said plurality of reliability levels acquired in said reliability level acquiring step;

wherein said object signal acquiring step includes generating said object signal by combining the plurality of transmission power control signals weighted in said weighting step.

8. A transmission power control method according to claim 4, comprising:

a weighting step for weighting the transmission power control signals received in said receiving step according to said plurality of reliability levels acquired in said reliability level acquiring step;

wherein said object signal acquiring step includes generating said object signal by combining the plurality of transmission power control signals weighted in said weighting step.

9. A transmission power control method according to claim 1, wherein said object signal acquiring step includes selecting one signal from among the transmission power control signals received in said receiving step based on said plurality of reliability levels acquired in said reliability level acquiring step, and taking the selected signal as said object signal.

10. A transmission power control method according to claim 2, wherein said object signal acquiring step includes selecting one signal from among the transmission power control signals received in said receiving step based on said plurality of reliability levels acquired in said reliability level acquiring step, and taking the selected signal as said object signal.

11. A transmission power control method according to claim 3, wherein said object signal acquiring step includes selecting one signal from among the transmission power control signals received in said receiving step based on said plurality of reliability levels acquired in said reliability level acquiring step, and taking the selected signal as said object signal.

12. A transmission power control method according to claim 4, wherein said object signal acquiring step includes selecting one signal from among the transmission power control signals received in said receiving step based on said plurality of reliability levels acquired in said reliability level acquiring step, and taking the selected signal as said object signal.

13. A transmission power control method according to claim 1, wherein said control content deciding step includes comparing said object signal determined in said object signal acquiring step with two preset threshold values, and selecting and determining the control content of said mobile station from among the three stages of an increase, maintenance or decrease of the transmission power based on the results of the comparison.

14. A transmission power control method according to claim 2, wherein said control content deciding step includes comparing said object signal determined in said object signal acquiring step with two preset threshold values, and selecting and determining the control content of said mobile station from among the three stages of an increase, maintenance or decrease of the transmission power based on the results of the comparison.

15. A transmission power control method according to claim 3, wherein said control content deciding step includes comparing said object signal determined in said object signal acquiring step with two preset threshold values, and selecting and determining the control content of said mobile station from among the three stages of an increase, maintenance or decrease of the transmission power based on the results of the comparison.

16. A transmission power control method according to claim 4, wherein said control content deciding step includes comparing said object signal determined in said object signal acquiring step with two preset threshold values, and selecting and determining the control content of said mobile station from among the three stages of an increase, maintenance or decrease of the transmission power based on the results of the comparison.

17. A transmission power control method according to claim 1, wherein control is performed in said control content deciding step by changing the transmission power of said mobile station by a control amount in accordance with said object signal determined in said object signal acquiring step.

18. A transmission power control method according to claim 2, wherein control is performed in said control content deciding step by changing the transmission power of said mobile station by a control amount in accordance with said object signal determined in said object signal acquiring step.

19. A transmission power control method according to claim 3, wherein control is performed in said control content deciding step by changing the transmission power of said mobile station by a control amount in accordance with said object signal determined in said object signal acquiring step.

20. A transmission power control method according to claim 4, wherein control is performed in said control content deciding step by changing the transmission power of said mobile station by a control amount in accordance with said object signal determined in said object signal acquiring step.

41. A base station for performing a transmission power control method according to claim 3, comprising:

parameter acquiring means for acquiring said parameter with respect to said mobile station based on an upward signal from said mobile station; and

transmission means for transmitting said parameter acquired by said parameter acquiring means to said mobile station.

21. A mobile station capable of simultaneously connecting with a plurality of base stations, comprising:

receiving means for receiving a transmission power control signal from each of said plurality of base stations;

reliability level acquiring means for acquiring a reliability level with respect to each of said plurality of base stations;

object signal acquiring means for determining an object signal based on said plurality of transmission power control signals received from said receiving means and said plurality of reliability levels acquired from said reliability level acquiring means;

control content deciding means for deciding a control content of the transmission power of said mobile station based on said object signal determined by said object signal acquiring means; and

control means for controlling the transmission power in accordance with said control content decided by said control content deciding means.

22. A mobile station according to claim 21, wherein said reliability level acquiring means acquires a parameter based on a signal from each of said plurality of base stations received by said receiving means, and generates a reliability level with respect to each of said plurality of base stations in accordance with said parameter.

23. A mobile station according to claim 21, wherein said reliability level acquiring means generates a reliability level with respect to each of said plurality of base stations in accordance with a parameter from each of said plurality of base stations received by said receiving means.

24. A mobile station according to claim 21, wherein said reliability level acquiring means takes the reliability level from each of said plurality of base stations received by said receiving means as the reliability level with respect to each of said plurality of base stations.

25. A mobile station according to claim 21, comprising:

weighting means for weighting each transmission power control signal received by said receiving means by the reliability level of a corresponding base station;

wherein said object signal acquiring means generates said object signal by combining the plurality of transmission control signals weighted by said weighting means.

26. A mobile station according to claim 22, comprising:

weighting means for weighting each transmission power control signal received by said receiving means by the reliability level of a corresponding base station;

wherein said object signal acquiring means generates said object signal by combining the plurality of transmission control signals weighted by said weighting means.

27. A mobile station according to claim 23, comprising:

weighting means for weighting each transmission power control signal received by said receiving means by the reliability level of a corresponding base station;

wherein said object signal acquiring means generates said object signal by combining the plurality of transmission control signals weighted by said weighting means.

28. A mobile station according to claim 24, comprising:

weighting means for weighting each transmission power control signal received by said receiving means by the reliability level of a corresponding base station;

wherein said object signal acquiring means generates said object signal by combining the plurality of transmission control signals weighted by said weighting means.

29. A mobile station according to claim 21, wherein said object signal acquiring means selects one from among said plurality of transmission power control signals to be said object signal.

30. A mobile station according to claim 22, wherein said object signal acquiring means selects one from among said plurality of transmission power control signals to be said object signal.

31. A mobile station according to claim 23, wherein said object signal acquiring means selects one from among said plurality of transmission power control signals to be said object signal.

32. A mobile station according to claim 24, wherein said object signal acquiring means selects one from among said plurality of transmission power control signals to be said object signal.

33. A mobile station according to claim 21, wherein said control content deciding means compares said object signal determined by said object signal acquiring means with two preset threshold values, and selects and decides from among the three stages of increase, maintenance or decrease of the transmission power as said control content based on the results of this comparison.

34. A mobile station according to claim 22, wherein said control content deciding means compares said object signal determined by said object signal acquiring means with two preset threshold values, and selects and decides from among the three stages of increase, maintenance or decrease of the transmission power as said control content based on the results of this comparison.

35. A mobile station according to claim 23, wherein said control content deciding means compares said object signal determined by said object signal acquiring means with two preset threshold values, and selects and decides from among the three stages of increase, maintenance or decrease of the transmission power as said control content based on the results of this comparison.

36. A mobile station according to claim 24, wherein said control content deciding means compares said object signal determined by said object signal acquiring means with two preset threshold values, and selects and decides from among the three stages of increase, maintenance or decrease of the transmission power as said control content based on the results of this comparison.

37. A mobile station according to claim 21, wherein said control content deciding means takes, as the control content, control performed by changing the transmission power by a control amount in accordance with said object signal determined by said object signal acquiring means.

38. A mobile station according to claim 22, wherein said control content deciding means takes, as the control content, control performed by changing the transmission power by a control amount in accordance with said object signal determined by said object signal acquiring means.

39. A mobile station according to claim 23, wherein said control content deciding means takes, as the control content, control performed by changing the transmission power by a control amount in accordance with said object signal determined by said object signal acquiring means.

40. A mobile station according to claim 24, wherein said control content deciding means takes, as the control content, control performed by changing the transmission power by a control amount in accordance with said object signal determined by said object signal acquiring means.

42. A recording medium containing a program to be run in a mobile station simultaneously connected to a plurality of base stations, the program comprising:

a receiving step for receiving a transmission power control signal form each of said plurality of base stations;

a reliability level acquiring step for acquiring a reliability level with respect to each of said plurality of base stations;

an object signal acquiring step for determining an object signal from said reliability levels acquired in said reliability level acquiring step and said plurality of transmission power control signals received in said receiving step;

a control content deciding step for deciding a control content of the transmission power of said mobile station based on said object signal determined in said object signal acquiring step; and

a control step for controlling the transmission power of said mobile station in accordance with said control decided by said control content deciding step.