WIRELESS COMMUNICATION SYSTEM AND METHOD OF CONTROLLING A TRANSMISSION POWER

• US 20160242214A1
• Filed: 04/26/2016
• Published: 08/18/2016
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: KURODA, Nahoko
• Granted Patent: US 10,306,678 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A base station is provided which notifies a mobile station of transmission power information for an uplink RACH, the mobile station transmits transmission delay estimation information on the RACH to the base station over the RACH at a transmission power based on the transmission power information, and the base station changes the transmission power information according to the transmission delay estimation information and notifies the mobile station of the changed transmission power information. The mobile station retransmits data or a preamble if the mobile station does not receive a notification that the base station has received the data or the preamble correctly after a predetermined time. The base station transmits the transmission power information over a BCH and a CPICH transmitted to a plurality of mobile stations.

Claims

1. A mobile station comprising:

a receiver configured to receive first information which is broadcasted by a base station; and

a transmitter configured to;

transmit second information to the base station, the second information being related with a number of RACH preambles sent until a successful RACH completion, and

transmit a RACH preamble with preamble transmission power to the base station, the preamble transmission power being calculated by the mobile station using the first information,

wherein the first information is optimized by the base station using the second information.

2. The mobile station according to claim 1,

wherein the first information is related with initial preamble power information, and

wherein the preamble transmission power is calculated using the initial preamble power information.

3. The mobile station according to claim 1,

wherein the first information is related with a power offset, and

wherein the preamble transmission power is calculated using a value of the power offset.

4. The mobile station according to claim 3,

wherein the receiver receives power increase step information and transmission power information, the power increase step information and the transmission power information being broadcasted by the base station, and

wherein the preamble transmission power is calculated using the power increase step information and the transmission power information.

5. The mobile station according to claim 4,

wherein the transmission power information is related with information of reference signal transmit power.

6. The mobile station according to claim 4,

wherein the preamble transmission power is calculated using average reception power information and a number of times of RACH preamble transmission, the average reception power information being measured by the mobile station, and the number of times of RACH preamble transmission being counted by the mobile station.

7. The mobile station according to claim 6,

wherein the preamble transmission power is calculated using a first value calculated by subtracting 1 from the number of times of RACH preamble transmission.

8. The mobile station according to claim 7,

wherein the preamble transmission power is calculated using a value calculated by multiplying the first value and the power increase step information.

9. A method of controlling a transmission power of a mobile station, the method comprising:

receiving first information which is broadcasted by a base station;

transmitting second information to the base station, the second information being related with a number of RACH preambles sent until a successful RACH completion; and

transmitting a RACH preamble with preamble transmission power to the base station, the preamble transmission power being calculated by the mobile station using the first information,

wherein the first information is optimized by the base station using the second information.

10. The method according to claim 9,

wherein the first information is related with initial preamble power information, and

wherein the preamble transmission power is calculated using the initial preamble power information.

11. The method according to claim 9,

wherein the first information is related with a power offset, and

wherein the preamble transmission power is calculated using a value of the power offset.

12. The method according to claim 11, further comprising:

receiving power increase step information and transmission power information, the power increase step information and the transmission power information being broadcasted by the base station, and

wherein the preamble transmission power is calculated using the power increase step information and the transmission power information.

13. The method according to claim 12,

wherein the transmission power information is related with information of reference signal transmit power.

14. The method according to claim 12,

wherein the preamble transmission power is calculated using average reception power information and a number of times of RACH preamble transmission, the average reception power information being measured by the mobile station, and the number of times of RACH preamble transmission being counted by the mobile station.

15. The mobile station according to claim 14,

wherein the preamble transmission power is calculated using a first value calculated by subtracting 1 from the number of times of RACH preamble transmission.

16. The mobile station according to claim 15,

wherein the preamble transmission power is calculated using a value calculated by multiplying the first value and the power increase step information.

17. A base station comprising:

a transmitter configured to broadcast first information to a mobile station; and

a receiver configured to;

receive second information from the mobile station, the second information being related with a number of RACH preambles sent until a successful RACH completion, and

receive a RACH preamble transmitted by mobile station with preamble transmission power, the preamble transmission power being calculated by the mobile station using the first information,

wherein the first information is optimized by the base station using the second information.

18. The base station according to claim 17,

wherein the first information is related with initial preamble power information, and

wherein the preamble transmission power is calculated using the initial preamble power information.

19. The base station according to claim 17,

wherein the first information is related with a power offset, and

wherein the preamble transmission power is calculated using a value of the power offset.

20. The base station according to claim 19,

wherein the transmitter broadcasts power increase step information and transmission power information to the mobile station, and

wherein the preamble transmission power is calculated using the power increase step information and the transmission power information.

21. The base station according to claim 20,

wherein the transmission power information is related with information of reference signal transmit power.

22. The base station according to claim 20,

wherein the preamble transmission power is calculated using average reception power information and a number of times of RACH preamble transmission, the average reception power information being measured by the mobile station, and the number of times of RACH preamble transmission being counted by the mobile station.

23. The mobile station according to claim 22,

wherein the preamble transmission power is calculated using a first value calculated by subtracting 1 from the number of times of RACH preamble transmission.

24. The base station according to claim 23,

wherein the preamble transmission power is calculated using a value calculated by multiplying the first value and the power increase step information.

25. A method of a base station controlling a transmission power of a mobile station, the method comprising:

broadcasting first information to a mobile station; and

receiving second information from the mobile station, the second information being related with a number of RACH preambles sent until a successful RACH completion, and

receiving a RACH preamble transmitted by mobile station with preamble transmission power, the preamble transmission power being calculated by the mobile station using the first information,

wherein the first information is optimized by the base station using the second information.

26. The method according to claim 25,

wherein the first information is related with initial preamble power information, and

wherein the preamble transmission power is calculated using the initial preamble power information.

27. The method according to claim 25,

wherein the first information is related with a power offset, and

wherein the preamble transmission power is calculated using a value of the power offset.

28. The method according to claim 27, further comprising:

broadcasting power increase step information and transmission power information to the mobile station,

wherein the preamble transmission power is calculated using the power increase step information and the transmission power information.

29. The method according to claim 28,

wherein the transmission power information is related with information of reference signal transmit power.

30. The method according to claim 28,

wherein the preamble transmission power is calculated using average reception power information and a number of times of RACH preamble transmission, the average reception power information being measured by the mobile station, and the number of times of RACH preamble transmission being counted by the mobile station.

31. The method according to claim 30,

wherein the preamble transmission power is calculated using a first value calculated by subtracting 1 from the number of times of RACH preamble transmission.

32. The method according to claim 31,

wherein the preamble transmission power is calculated using a value calculated by multiplying the first value and the power increase step information.