Battery operated radio receivers having power save by reducing active reception time

• US 6,606,490 B1
• Filed: 08/10/1999
• Issued: 08/12/2003
• Est. Priority Date: 08/10/1999
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Yellin, Daniel, Rainish, Doron, Spencer, Paul
• Primary Examiner(s): APPIAH, CHARLES NANA
• Application Number:
  US09/371,276
• Time in Patent Office: 1,463 Days
• Field of Search: 455/343, 455/38.3, 455/127, 455/574, 455/135, 370/311, 370/330, 370/337, 370/347, 370/324, 370/458, 370/459, 370/468, 340/7.31, 340/7.32, 340/7.34, 340/825.2, 340/10.34
• US Class Current: 455/343.1
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A battery-powered portable radio receiver and a method of operating the battery-powered radio receiver during Standby Mode in order to decrease battery-current drain is provided. In Standby Mode, a receive path of the radio receiver is activated during a data-detection time interval for the detection of data destined for selected receivers, and a preconditioning time interval for performing pre-conditioning functions with respect to the receiver before the data-detection time interval. The method includes: (a) activating the receive path at a predetermined time instant before the start of the data-detection time interval to perform the pro-conditioning functions with respect to the receiver, (b) detecting a predetermined characteristic of the received signal affected by each of the pre-conditioning functions; (c) comparing each of the predetermined characteristics with e threshold; (d) where the predetermined characteristics are within their respective thresholds, deactivating the receive path until the start of the data-detection time interval, and then reactivating the receive path fur the data-detection time interval; and (e) where the predetermined characteristics are outside their respective thresholds, continuing the pre-conditioning functions until the predetermined characteristics are within their respective thresholds, then deactivating the receive path until the start of the data-detection time interval, and then reactivating the receive path for the data-detection time interval.

Claims

1. A method comprising:

(a) activating a receive path at a predetermined time instant in a frame before the start of a data-detection time interval of said frame, thus beginning a pre-conditioning period;

(b) performing during said pre-conditioning period pre-conditioning functions with respect to a receiver;

(c) detecting during said pre-conditioning period predetermined characteristics of a received signal, said predetermined characteristics affected by one or more of said pre-conditioning functions;

(d) deactivating said receive path at a time instant later than said predetermined time instant until the start of the data-detection time interval, thus terminating said pre-conditioning period prior to the start of said data-detection time interval, and then reactivating said receive path for the data-detection time interval, in the event that said predetermined characteristics are within corresponding thresholds; and

(e) in the event that said predetermined characteristics are outside said corresponding thresholds repeating stems (b) and (c) until stet) (d) can be performed.

2. The method according to claim 1, wherein said pre-conditioning functions include an automatic gain control (AGC) function, and one of said predetermined characteristics affected thereby is a measurement of the power of the received signal.

3. The method according to claim 2, wherein said threshold of the AGC function is a window defined by maximum and minimum powers of the received signal.

4. The method according to claim 3, wherein said receiver is a “

RAKE”

receiver, and said multipath search function is a finger-positioning function.

5. The method according to claim 1, wherein said pre-conditioning functions include a multipath search function, and one of said predetermined characteristics affected thereby is a measurement of the quality of the received signal.

6. The method according to claim 5, wherein said threshold of the multipath search function is based on the sum of the signal to noise and interference ratios of all found paths.

7. The method according to claim 1, wherein said pre-conditioning functions include:

an automatic gain control (AGC) function, wherein one of said predetermined characteristics affected thereby is a measurement of the power of said received signal; and

a multipath search function, wherein one of said predetermined characteristics affected thereby is a measurement of the quality of the received signal.

8. The method according to claim 7, wherein said multipath search function is performed immediately following said automatic gain control function.

9. The method according to claim 7, wherein said multipath search function is performed concurrently with said automatic gain control function.

10. The method according to claim 7, wherein said preconditioning functions also include a frequency tracking function which is performed during said data-detection time interval.

11. A portable radio receiver comprising:

data-detection circuitry in a receive path adapted to detect data destined for a selected receiver;

pre-conditioning circuitry in said receive path adapted to pre-condition said radio receiver using pre-conditioning functions during a pre-conditioning period; and

control circuitry coupled to said data-detection circuitry and said pre-conditioning circuitry, said control circuitry adapted to activate said receive path for said pre-conditioning period, to deactivate at least a part of said receive path during a time interval in a frame that precedes a data-detection time interval of said frame thus terminating said pre-conditioning period prior to said data-detection time interval when predetermined characteristics of a signal received during said frame are within corresponding thresholds and to reactivate said receive path for said data-detection time interval, each of said predetermined characteristics affected by one or more of said preconditioning functions.

12. The radio receiver according to claim 11, wherein said pre-conditioning circuitry includes an automatic gain control (AGC) circuit, and said control circuitry includes a received power comparator for comparing the power of the received signal against upper and lower thresholds.

13. The radio receiver according to claim 12, wherein said control circuitry is adapted to define a window threshold of maximum and minimum powers for controlling the AGC circuit.

14. The radio receiver according to claim 13, wherein said receiver is a “

RAKE”

receiver, and said multipath search circuit is a finger-positioning circuit.

15. The radio receiver according to claim 11, wherein said pre-conditioning circuitry includes a multipath search circuit, and said control circuitry includes a signal quality estimator for measuring the quality of the received signal.

16. The radio receiver according to claim 15, wherein said control circuitry is adapted to define a threshold for the multipath search circuit based on the sum of the signal to noise and interference ratios of all found paths.

17. The radio receiver according to claim 11, wherein said pre-conditioning circuits include an automatic gain control (AGC) circuit, wherein one of said predetermined characteristics is a measurement of the power of the received signal;

and a multipath search circuit, wherein one of said predetermined characteristics is a measurement of the quality of the received signal.

18. The radio receiver according to claim 17, wherein said control circuitry is adapted to effect an automatic gain control function and to effect a multipath search function immediately afterwards.

19. The radio receiver according to claim 17, wherein said control circuitry is adapted to effect a multipath search function and an automatic gain control function concurrently.

20. The radio receiver according to claim 17, wherein said pre-conditioning circuitry also include a frequency tracking circuit which is controlled by said control circuitry to operate during said data-detection time interval.

21. A method comprising activating a receive path of a receiver at a predetermined time instant in a frame before the start of a data detection time interval of said frame, thus beginning a conditioning period comprising:

during said pre-conditioning period, estimating predetermined characteristics of a signal received by said receiver during said frame, said predetermined characteristics affected by pre-conditioning functions performed on said receiver during said pre-conditioning period; and

deactivating at least part of said receive path until the start of said data-detection time interval, thus terminating said pre-conditioning period prior to the start of said data-detection time interval, in the event that said predetermined characteristics are within corresponding thresholds.

22. The method of claim 21, wherein said pre-conditioning functions include an automatic gain control function, and wherein estimating said predetermined characteristics comprises estimating an estimated power of said signal.

23. The method of claim 21, wherein said pre-conditioning functions include a multipath search function, and wherein estimating said predetermined characteristics comprises determining an estimated signal-to-noise-and-interference of said signal.

24. A portable radio receiver comprising:

data-detection circuitry in a receive path adapted to detect data destined for a selected receiver;

pre-conditioning circuitry in said receive path adapted to pre-condition said radio receiver using pre-conditioning functions during a pre-conditioning period; and

control circuitry coupled to said data-detection circuitry and said pre-conditioning circuitry, said control circuitry able to activate said receive path for said pre-conditioning period and to deactivate at least part of said receive path until the start of a data-detection time interval of a frame thus terminating said pre-conditioning period prior to said data-detection time interval when predetermined characteristics of a signal received by said receive path during said frame are within corresponding thresholds, each of said predetermined characteristics affected by one or more of said preconditioning functions.

25. The receiver of claim 24, wherein said pre-conditioning functions include an automatic gain control function, and wherein said predetermined characteristics include an estimated power of said signal.

26. The receiver of claim 24, wherein said pre-conditioning functions include a multipath search function, and wherein said predetermined characteristics include an estimated signal-to-noise-and-interference of said signal.