Systems and Methods for Reducing Power Consumption of a Communications Device Using Multiple Elements in a Receiver Chain

• US 20130072256A1
• Filed: 09/19/2011
• Published: 03/21/2013
• Est. Priority Date: 09/19/2011
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: SU, Jin-Sheng
• Granted Patent: US 8,874,055 B2
• Time in Patent Office: Days
• US Class Current: 455/558
• CPC Class Codes: H04W 52/0274 by switching on or off the equipment or parts thereof
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Systems and methods according to embodiments of the present invention are provided for increasing the power efficiency of a communications device by allowing it to support dual-SIM functionality while issuing simultaneous wake ups for each SIM. Embodiments of the present invention leverage time sharing solutions to minimize the amount of circuitry needed in a communications device to issue wake ups while avoiding the drawbacks of other time sharing solutions that result in increased overhead due to requiring multiple transitions from an idle state to an active state.

Claims

1. A communications device comprising:

a first receiver coupled to a first phase lock loop (PLL);

a second receiver coupled to a second PLL;

a transmitter coupled to the second PLL; and

a controller coupled to the first PLL and the second PLL, wherein the controller is configured to initiate a first wake up signal for the first receiver and to initiate a second wake up signal for the second receiver.

2. The communications device of claim 1, wherein the first wake up signal and the second wake up signal are transmitted simultaneously.

3. The communications device of claim 1, wherein the communications device is in an idle state when the first wake up signal and the second wake up signal are transmitted.

4. The communications device of claim 1, further comprising:

a first subscriber identity module (SIM) coupled to the first receiver; and

a second SIM coupled to the second receiver,

wherein the first SIM is associated with a first cellular phone service, and wherein the second SIM is associated with a second cellular phone service.

5. The communications device of claim 1, wherein the first receiver is a main receiver of a cellular telephone, and wherein the second receiver is a diversity receiver of a cellular telephone.

6. The communications device of claim 1, wherein the controller is configured to select a first transmitter for transmitting a first service to the first receiver and a second transmitter for transmitting a second service to the second receiver such that a difference in transmission time from the communications device to the first transmitter and from the communications device to the second transmitter is minimized.

7. The communications device of claim 1, wherein the second receiver is further coupled to the second PLL.

8. A communications device comprising:

a first receiver coupled to a first phase lock loop (PLL);

a second receiver coupled to a second PLL;

a transmitter coupled to the second PLL; and

a controller coupled to the first PLL and the second PLL, wherein the controller is configured to initiate a first wake up signal for the second receiver while a transmission is in progress using the first receiver.

9. The communications device of claim 8, wherein the controller is further configured to:

instruct the second PLL to transmit data to the transmitter while the transmission is in progress;

determine that a wake up signal is to be sent to the second receiver;

instruct the second PLL to transmit the wake up signal to the second receiver; and

instruct the second PLL to continue transmitting data to the transmitter after the wake up signal has been sent to the second receiver.

10. The communications device of claim 8, further comprising:

a first multiplexer (MUX) coupled to the second PLL, the transmitter, and the second receiver.

11. The communications device of claim 10, wherein the MUX is configured to use time division multiplexing to transmit the first wake up signal from the controller to the second receiver via the second PLL while the transmission is in progress using the first receiver.

12. The communications device of claim 8, wherein the second receiver is further coupled to the first PLL.

13. The communications device of claim 8, wherein the controller is further configured to initiate a second wake up signal for the first receiver while a second transmission is in progress using the second receiver.

14. The communications device of claim 13, wherein the controller is further configured to:

instruct the first PLL to receive data from the second receiver while the second transmission is in progress;

determine that a wake up signal is to be sent to the first receiver;

instruct the first PLL to transmit the second wake up signal to the first receiver; and

instruct the first PLL to continue receiving data from the second receiver after the wake up signal has been sent to the first receiver.

15. The communications device of claim 8, further comprising:

a first subscriber identity module (SIM) coupled to the first receiver; and

a second SIM coupled to the second receiver,

wherein the communications device is a cellular telephone, wherein the first SIM is associated with a first cellular phone service, and wherein the second SIM is associated with a second cellular phone service.

16. The communications device of claim 8, wherein the controller is configured to select a first transmitter for transmitting a first service to the first receiver and a second transmitter for transmitting a second service to the second receiver such that a difference a difference in transmission time from the communications device to the first transmitter and from the communications device to the second transmitter is minimized.

17. A method for sending wake up signals in a communications device having first and second receivers, the method comprising:

determining that a first wake up signal should be sent to the first receiver and a second wake up signal should be sent to the second receiver; and

initiating the first wake up signal for the first receiver via a first phase lock loop (PLL) and a second wake up signal to the second receiver via a second PLL.

18. The method of claim 17, wherein the first wake up signal and the second wake up signal are simultaneously transmitted while the communications device is in idle mode.

19. The method of claim 17, further comprising:

detecting a first plurality of transmitters transmitting a first service;

detecting a second plurality of transmitters transmitting a second service; and

selecting a first transmitter in the first plurality of transmitters and a second transmitter in the second plurality of transmitters such that a difference between a first transmission time from the communications device to the first transmitter and a second transmission time from the communications device to the second transmitter is minimized.

20. The method of claim 19, further comprising:

calculating a wake up signal transmission time based on the first transmission time and the second transmission time; and

simultaneously transmitting the first wake up signal and the second wake up signal at the wake up signal transmission time.