DETERMINING PER SECTOR RECEIVED POWER LEVEL

• US 20080242294A1
• Filed: 03/24/2008
• Published: 10/02/2008
• Est. Priority Date: 03/26/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gore, Dhananjay Ashok, Sampath, Hemanth, Teague, Edward Harrison
• Granted Patent: US 7,966,011 B2
• Time in Patent Office: Days
• US Class Current: 455/425
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/246 where the output power of a terminal is based on a path parameter calculated in said terminal
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

At a mobile device, a total received power represents signals received from all access points. In order to calculate an appropriate transmit power for communication with a single access point, a mobile device determines a per sector received power level. The mobile device can ascertain a time-domain channel response from each access point pilot signal, ascertain a received digital power lever per sector from each access point pilot signal and, based in part on the digital power level, calculate a received power level from each access point. A per sector received power level can be utilized to conserve battery power and/or to reduce interference in a wireless communications network.

Claims

1. A method for determining per sector received power level, comprising:

receiving an access point pilot signal from each access point;

determining a time-domain channel response from each access point pilot signal;

determining a received digital power level per sector from each access point pilot signal; and

determining a received power level from each access point based on at least the digital power level, wherein the access point represents a sector.

2. The method of claim 1, wherein the received power level from each access point is computed from the digital power level per sector, an Analog Front-End Receiver Gain, a Digital Front-End Receiver Gain, and a total received power at an output of an Analog-to-Digital Converter (ADC).

3. The method of claim 2, further comprising:

computing an estimated energy at the output of an ADC per sector as

4. The method of claim 2, further comprising:

mapping the estimated energy at the output of the ADC per sector to a dBm power level, comprising;

normalizing the estimated energy to a full-scale ADC power, and;

subtracting an analog gain.

5. The method of claim 1, wherein the determined received power level is utilized to set a transmit power of a reverse link serving sector to determine handoff.

6. The method of claim 1, determining a time-domain channel response, comprising:

obtaining a per sector channel tap estimation of sector specific received signal power.

7. A wireless communications apparatus, comprising:

a memory that retains instructions related to receiving an access point pilot signal from each access point;

determining a time-domain channel response from each access point pilot signal, establishing a received digital power level per sector from each access point pilot signal and calculating a received power level from each access point based on at least the digital power level, wherein an access point represents a sector.

a processor, coupled to the memory, configured to execute the instructions retained in the memory.

8. The wireless communications apparatus of claim 7, wherein the received power level from each access point is computed from the digital power level per sector, an Analog Front-End Receiver Gain, a Digital Front-End Receiver Gain and a total received power at an output of an Analog-to-Digital Converter (ADC).

9. The wireless communications apparatus of claim 8, the memory further retains instructions related to computing an estimated energy at the output of an ADC per sector as

10. The wireless communications apparatus of claim 8, the memory further retains instructions related to mapping the estimated energy at the output of the ADC per sector to a dBm power level by normalizing the estimated energy to a full-scale ADC power and subtracting an analog gain.

11. The wireless communications apparatus of claim 7, wherein the determined received power level is utilized to set a transmit power of a reverse link serving sector to determine handoff.

12. The wireless communications apparatus of claim 7, the memory further retains instructions related to obtaining a per sector channel tap estimation of sector specific received signal power.

13. A wireless communications apparatus operable in a wireless communication system, the apparatus comprising:

means for receiving a plurality of access point pilot signals;

means for determining a time-domain channel response from each access point pilot signal of the plurality of access point pilot signals;

means for determining a received digital power level per sector from each access point pilot signal; and

means for determining a received power level from each access point based on at least the digital power level.

14. The wireless communications apparatus of claim 13, wherein the received power level from each access point is computed from the digital power level per sector, an Analog Front-End Receiver Gain, a Digital Front-End Receiver Gain, and a total received power at an output of an Analog-to-Digital Converter (ADC).

15. The wireless communications apparatus of claim 14, further comprising:

means for computing an estimated energy at the output of an ADC per sector for sector-index s and antenna index k is given by

16. The wireless communications apparatus of claim 14, further comprising:

means for mapping the estimated energy at the output of the ADC per sector to a dBm power level, comprising;

means for normalizing the estimated energy to a full-scale ADC power, and;

means for subtracting an analog gain.

17. The wireless communications apparatus of claim 13, wherein the determined received power level is utilized to set a transmit power of a reverse link serving sector to determine handoff.

18. The wireless communications apparatus of claim 13, wherein the means for determining a time-domain channel response comprises:

means for obtaining a per sector channel tap estimation of sector specific received signal power.

19. The wireless communications apparatus of claim 13, wherein each of the plurality of access point pilot signals is received from a different access point that represents a sector.

20. A machine-readable medium having stored thereon machine-executable instructions for determining a per sector received power level, comprising:

receiving a plurality of access point pilot signals, each access point pilot signal is from a single access point;

determining a time-domain channel response from each access point pilot signal of the plurality of access point pilot signals;

establishing a received digital power level per sector from each access point pilot signal; and

calculating a received power level from each access point based on at least the digital power level, wherein the received power level from each access point is computed from the digital power level per sector, an Analog Front-End Receiver Gain, a Digital Front-End Receiver Gain, and a total received power at an output of an Analog-to-Digital Converter (ADC).

21. The machine-readable medium of claim 20, the instructions further comprising:

computing an estimated energy at the output of an ADC per sector as

22. The machine-readable medium of claim 21, the instructions further comprising:

mapping the estimated energy at the output of the ADC per sector to a dBm power level by normalizing the estimated energy to a full-scale ADC power and subtracting an analog gain.

23. In a wireless communications system, an apparatus comprising:

a processor configured to;

receive a plurality of access point pilot signals, each pilot signal is from a different access point;

ascertain a time-domain channel response from each access point pilot signal;

determine a received digital power level per sector from each access point pilot signal; and

calculate a received power level from each access point based on at least the digital power level.

24. The wireless communications system of claim 23, the processor further configured to calculate an estimated energy at the output of an ADC per sector as

25. The wireless communications system of claim 23, the processor further configured to compute the received power level from each access point for the digital power level per sector, an Analog Front-End Receiver Gain, a Digital Front-End Receiver Gain, and a total received power at an output of an Analog-to-Digital Converter.