Forward link closed loop power control for a third generation wideband CDMA system

• US 6,377,813 B1
• Filed: 12/03/1998
• Issued: 04/23/2002
• Est. Priority Date: 12/03/1998
• Status: Expired due to Term

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Tran, Jean-Marie, Kansakoski, Antti
• Primary Examiner(s): Nguyen, Lee
• Application Number:
  US09/205,137
• Time in Patent Office: 1,237 Days
• Field of Search: 455/69, 455/522, 455/238.1, 370/335, 370/342, 375/140, 375/142
• US Class Current: 455/522
• CPC Class Codes: H04B 7/01 Reducing phase shift
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 52/286 during data packet transmission, e.g. high speed packet access [HSPA]

Abstract

A wireless telecommunications mobile station, which is bi-directionally coupled to a base station through a communication channel, includes a device for receiving signals over the communication channel from the base station, power control circuitry for selectively deriving power control commands, and a device for transmitting the selectively derived power control commands to the base station. The power control circuitry of the mobile station provides, in cooperation with power control circuitry of the base station, closed loop power control to the communication channel. The power control circuitry includes circuitry for selectively deriving power control commands based on one of first power control commands or second power control commands in response to a determined mobility of the mobile station. The determined mobility can be indicative of a Doppler shift of carrier transmitted from the base station, or a velocity derived from the Doppler shift.

Claims

1. A wireless telecommunications base station comprising a transceiver for being bidirectionally coupled to at least one mobile station through a radio communication channel, the base station further comprising:

means for receiving power control signals over the radio communication channel from the mobile station; and

power circuitry for a in cooperation with the mobile station, closed loop power control to the radio communication channel, wherein the power control circuitry comprises circuitry for determining a mobility of the mobile station and for selectively deriving power control commands based on one of first power control commands or second power control commands in response to the determined mobility of the mobile station, said second power control commands including open loop power control commands;

means for determining a Doppler condition of the mobile station; and

wherein said first power control commands are derived when said mobile station is in a low Doppler condition, and wherein said second power control commands are derived when said mobile station is in a high Doppler condition.

2. A wireless telecommunications base station as in claim 1, wherein the circuitry is comprised of:

means for determining a Doppler condition of the mobile station;

means for optionally determining a velocity of the mobile station from the determined Doppler condition; and

means for selectively deriving the first power control commands from the received power control signals and for deriving the second power control commands from one of default power control commands or modifications to the first power control commands.

3. A wireless telecommunications base station as in claim 1, wherein the circuitry is comprised of means for extracting at least one of a mobile station determined Doppler condition or velocity from the received power control signals.

4. A wireless telecommunications base station as in claim 1, wherein the circuitry is responsive to at least one of an output of a speed estimation algorithm, a received signal strength measurement, or a received signal error rate measurement.

5. A wireless telecommunications base station as in claim 4, wherein the received power control signals include speed estimation variables for use in the speed estimation algorithm.

6. A method for operating a wireless telecommunications base station, comprising steps of:

receiving power control signals over a radio communication channel from the mobile station;

determining a mobility of the mobile station at least in part from the received power control signals, including determining a Doppler condition of the mobile station;

selectively deriving power control commands based on one of first power control commands or second power control commands in response to the determined mobility of the mobile station, said second power control commands including open loop power control commands; and

deriving said first power control commands when said mobile station is in a low Doppler condition, and deriving said second power control commands when said mobile station is in a high Doppler condition;

transmitting the power control commands to the radio communication channel.

7. A method as in claim 6, wherein the determining step is comprised of:

determining a Doppler condition of the mobile station; and

optionally determining a velocity of the mobile station from the determined Doppler condition;

wherein the step of selectively deriving operates to derive the first power control commands from the received power control signals and the second power control commands from one of default power control commands or modifications to the first power control commands.

8. A method as in claim 6, wherein the determining step is comprised of means for extracting at least one of a mobile station determined Doppler condition or velocity from the received power control signals.

9. A method as in claim 6, wherein the determining step is responsive to at least one of an output of a speed estimation algorithm, a received signal strength measurement, or a received signal error rate measurement.

10. A method as in claim 9, wherein the received power control signals include speed estimation variables for use in the speed estimation algorithm.

11. A method of operating a wireless telecommunications system, the method comprising steps of:

transmitting power control signals over a radio communication channel from a mobile station to a fixed station;

receiving the power control signals from the radio communication channel at the fixed station; and

adjusting a transmitted power in accordance with the received power control signals;

wherein

the step of transmitting includes a preliminary step of determining an amount of Doppler shift of a carrier signal that is transmitted from the base station to the mobile station; and

selectively deriving power control commands based on one of first power control commands or second power control commands in response to the determined Doppler shift, said second power control commands including open loop power control commands; and

the step of selectively deriving power control commands includes deriving said first power control commands when said mobile station is in a low Doppler condition, and deriving said second power control commands when said mobile station is in a high Doppler condition.

12. A method of operating a wireless telecommunications system, the method comprising steps of:

transmitting power control signals over a radio communication channel from a mobile station to a fixed station;

receiving the power control signals from the radio communication channel at the fixed station; and

adjusting a transmitted power in accordance with the received power control signals;

wherein

the step of transmitting includes preliminary steps of determining an amount of Doppler shift of a carrier signal that is transmitted from the fixed station to the mobile station; and

estimating a velocity of the mobile station, relative to the fixed station, from the determined amount of Doppler shift; and

selectively deriving power control commands based on one of first power control commands or second power control commands in response to the determined Doppler shift, said second power control commands including open loop power control commands; and

the step of selectively deriving power control commands includes deriving said first power control commands when said mobile station is in a low Doppler condition, and deriving said second power control commands when said mobile station is in a high Doppler condition.

13. A wireless telecommunications mobile station, said mobile station comprising a transceiver for being bidirectionally coupled to a base station through a radio communication channel, the mobile station further comprising:

receiver circuitry for receiving signals over the radio communication channel from the base station;

power control circuitry for determining a mobility of said mobile station relative to said base station and for providing, in cooperation with said base station, closed loop power control to the radio communication channel, said power control circuitry comprising;

means for determining a Doppler condition of said mobile station,

circuitry for selectively deriving power control commands based on one of first power control commands or second power control commands in response to the determined mobility of said mobile station relative to said base station, said second power control commands including open loop power control commands,

means, responsive to said determined Doppler condition, for selectively deriving said first power control commands from said communication channel or for deriving said second power control commands from one of default power control commands or modifications to said first power control commands;

wherein said first power control commands are derived when said mobile station is in a low Doppler condition, and wherein said second power control commands are derived when said mobile station is in a high Doppler condition; and

transmitter circuitry for transmitting said selectively derived power control commands to said base station.

14. A wireless telecommunications mobile station as in claim 13, wherein said power control circuitry determines the mobility using one of a zero crossing rate, a level crossing rate, or a covariance function estimation routine.

15. A wireless telecommunications mobile station as in claim 13, wherein said default power control commands are comprised of repeated power up and power down commands.

16. A wireless telecommunication mobile station as in claim 13, wherein said modifications to said first power control commands are formed by integrating said first power control commands over a period of time.

17. A wireless telecommunications mobile station as in claim 16, wherein the period of time is comprised of at least one frame period.

18. A wireless telecommunications mobile station, said mobile station comprising a transceiver for being bidirectionally coupled to a base station through a radio communication channel, said mobile station further comprising:

receiver circuitry for receiving signals over said radio communication channel from said base station;

power control circuitry for determining a mobility of said mobile station relative to said base station and for providing, in cooperation with said base station, closed loop power control to the radio communication channel, said power control circuitry comprising circuitry for selectively deriving power control commands based on one of first power control commands or second power control commands in response to the determined mobility of said mobile station relative to said base station, said second power control commands including open loop power control commands,

wherein said power control circuitry determines the mobility by estimating a velocity of said mobile station, and further compares the estimated velocity to a velocity threshold value for selectively deriving the power control commands based on one of the first power control commands or the second power control commands; and

transmitter circuitry for transmitting said selectively derived power control commands to said base station.

19. A wireless telecommunications mobile station as in claim 18, wherein said velocity threshold value is above about 30 km/h in a frequency band of about 2 GHz, and over about 60 km/h in a frequency band of about 1 GHz.

20. A method of operating a wireless telecommunications mobile station, comprising the steps of:

bidirectionally coupling a base station to the mobile station through a radio communication channel;

determining a Doppler condition of the mobile station;

selectively deriving power control commands based on one of first power control commands or second power control commands in response to determining the Doppler condition, the second power control commands providing open loop power control to the radio communication channel; and

wherein the first power control commands are derived from the radio communication channel when the mobile station is in a low Doppler condition, and wherein the second power control commands are derived from one of default power control commands or modifications to the first power control commands when the mobile station is in a high Doppler condition.

21. A method as in claim 20, wherein the step of determining includes steps of:

estimating a velocity of the mobile station; and

comparing the estimated velocity to a velocity threshold value;

wherein

the estimated velocity is used for selectively deriving the power control commands based on one of the first power control commands or the second power control commands.

22. A method as in claim 21, wherein the velocity threshold value is above about 30 km/h in a frequency band of about 2 GHz, and over about 60 km/h in a frequency band of about 1 GHz.