Dynamic adjustment of forward-link traffic-channel power levels based on forward-link RF conditions

• US 8,140,101 B1
• Filed: 03/19/2007
• Issued: 03/20/2012
• Est. Priority Date: 03/19/2007
• Status: Active Grant

• Current Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: Wurtenberger, Andrew M., Talley, Ryan S.
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): DEAN, JR, JOSEPH E
• Application Number:
  US11/688,135
• Time in Patent Office: 1,828 Days
• Field of Search: 455/522
• US Class Current: 455/522
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

Methods and systems are provided for dynamic adjustment of forward-link traffic-channel power levels based on forward-link RF conditions. In an exemplary embodiment, a base station provides service on a carrier in a wireless coverage area. The base station computes an E_c/I_or value for the carrier. Based at least in part on the computed E_c/I_or value, the base station adjusts at least one of an initial traffic-channel power level, a minimum traffic-channel power level, and a maximum traffic-channel power level for the carrier. As an example, if E_c/I_or is above a certain threshold, the base station may increase all three of the power levels, so as to improve service quality and coverage of its traffic channels, among other advantages.

Claims

1. A method comprising:

a base station providing service on a carrier in a wireless coverage area;

computing an E_c/I_or value for the carrier, wherein the computed E_c/I_or value comprises a logarithmic ratio of a pilot-channel power level to an all-channel power level,

wherein the pilot-channel power level is the amount of power the base station is allocating for transmitting a pilot channel on a forward link of the carrier, and

wherein the all-channel power level is the total amount of power the base station is allocating for transmitting all channels, including the pilot channel, on the forward link of the carrier; and

adjusting an initial traffic-channel power level for the carrier based at least in part on the computed E_c/I_or value,

wherein the initial traffic-channel power level is a power level at which, on a coverage-area-wide basis, and for all traffic channels assigned by the base station on the carrier before any next such adjustment is made, the base station initially transmits on the forward link to mobile stations operating on the carrier, and

wherein a plurality of traffic channels are assigned by the base station on the carrier before any next such adjustment is made.

2. The method of claim 1, wherein the base station comprises at least one of a base transceiver station, a base station controller, a radio network controller, and an access node.

3. The method of claim 1, wherein the service comprises code division multiple access (CDMA) service.

4. The method of claim 1, wherein the wireless coverage area comprises at least one of a cell and a sector.

5. The method of claim 1, wherein the forward link of the carrier comprises the pilot channel, a paging channel, and a sync channel.

6. The method of claim 5, wherein the forward link of the carrier further comprises one or more traffic channels.

7. The method of claim 1, wherein adjusting the initial traffic-channel power level for the carrier based at least in part on the computed E_c/I_or value comprises comparing the computed E_c/I_or value with at least one of an upper forward-link radio-frequency (RF) threshold and a lower forward-link RF threshold, wherein the upper forward-link RF threshold is greater than the lower forward-link RF threshold.

8. The method of claim 7, wherein the upper forward-link RF threshold is −

4 dB, and wherein the lower forward-link RF threshold is −

7 dB.

9. The method of claim 7, wherein adjusting the initial traffic-channel power level for the carrier based at least in part on the computed E_c/I_or value further comprises:

if the computed E_c/I_or value is greater than the upper forward-link RF threshold, then increasing the initial traffic-channel power level.

10. The method of claim 7, wherein adjusting the initial traffic-channel power level for the carrier based at least in part on the computed E_c/I_or value further comprises:

if the computed E_c/I_or value is less than the lower forward-link RF threshold, then decreasing the initial traffic-channel power level.

11. The method of claim 1, further comprising:

adjusting a minimum traffic-channel power level for the carrier based at least in part on the computed E_c/I_or value.

12. The method of claim 1, further comprising:

adjusting a maximum traffic-channel power level for the carrier based at least in part on the computed E_c/I_or value.

13. The method of claim 1, carried out on a periodic basis.

14. A base station comprising:

a wireless-communication interface;

a processor; and

data storage containing instructions executable by the processor for;

providing service on a carrier in a wireless coverage area;

computing an E_c/I_or value for the carrier, wherein the computed E_c/I_or value comprises a logarithmic ratio of a pilot-channel power level to an all-channel power level,

wherein the pilot-channel power level is the amount of power the base station is allocating for transmitting a pilot channel on a forward link of the carrier, and

wherein the all-channel power level is the total amount of power the base station is allocating for transmitting all channels, including the pilot channel, on the forward link of the carrier; and

adjusting an initial traffic-channel power level for the carrier based at least in part on the computed E_c/I_or value,

wherein the initial traffic-channel power level is a power level at which, on a coverage-area-wide basis, and for all traffic channels assigned by the base station on the carrier before any next such adjustment is made, the base station initially transmits on the forward link to mobile stations operating on the carrier, and

wherein a plurality of traffic channels are assigned before any next such adjustment is made.

15. The base station of claim 14, wherein adjusting the initial traffic-channel power level for the carrier based at least in part on the computed E_c/I_or value comprises

comparing the computed E_c/I_or value with at least one of an upper forward-link radio-frequency (RF) threshold and a lower forward-link RF threshold, wherein the upper forward-link RF threshold is greater than the lower forward-link RF threshold;

if the computed E_c/I_or value is greater than the upper forward-link RF threshold, then increasing the initial traffic-channel power level; and

if the computed E_c/I_or value is less than the lower forward-link RF threshold, then decreasing the initial traffic-channel power level.