Adaptive control of RF low power modes in a multi-rate wireless system using MCS value

Patent metadata

Field	Value
Publication number	US-9804664-B2
Application number	US-201414287663-A
Country	US
Kind code	B2
Filing date	May 27, 2014
Priority date	May 27, 2014
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

Methods, systems, and devices are described for power conservation in a wireless communications system. In embodiments, power conservation may be achieved by adaptively controlling power modes of a wireless communication device, using a modulation and coding scheme (MCS) value as a factor for guidance. According to one aspect, the device may be in a reception mode. While in a first power mode, the device may receive control information for incoming data that is being transmitted via a transmission frame. The control information may be located in a first portion of the frame with the data following in a second portion of the frame. The control information may include or otherwise indicate an MCS value corresponding to the MCS applied to the incoming data. Based on the MCS value, the device may be adaptively switched to a second power mode for receiving the incoming data.

First claim

What is claimed is:

1. A method of adaptive power control for a wireless communication device, comprising:
receiving control information for incoming data in a transmission frame while in a first power mode of the device, the control information including a modulation and coding scheme (MCS) value;
adjusting for phase error before switching to a second power mode to mitigate phase error caused by switching, wherein the adjusting comprises implementing an MCS rate for a transition point between the first power mode and the second power mode, the implemented MCS rate being lower than an MCS rate associated with the second power mode and having error vector magnitude (EVM) constraints that mitigate phase error caused by switching; and
adaptively switching to the second power mode of the device during the transmission frame, wherein the switching is based at least in part on the received MCS value and a bandwidth mode for reception.

2. The method of claim 1 , further comprising:
receiving incoming data of the transmission frame while in the second power mode.

3. The method of claim 1 , wherein the second power mode is a lower power mode than the first power mode.

4. The method of claim 3 , wherein adaptively switching to the second power mode comprises:
switching from a main synthesizer routed to each of a plurality of transmission/reception (Tx/Rx) chains associated with a modem for the first power mode to a plurality of local synthesizers routed respectively to one of the plurality of Tx/Rx chains for the second power mode.

5. The method of claim 3 , wherein adaptively switching to the second power mode comprises:
changing a voltage source of a phase locked loop (PLL), a synthesizer, or both;
turning off a low dropout regulator (LDO) of a PLL, an LDO of a synthesizer, or both;
changing a bias current to a circuit;
or a combination thereof.

6. The method of claim 1 , wherein adjusting for phase error comprises:
increasing a bandwidth of a synthesizer loop to increase a settling rate of an associated voltage-controlled oscillator (VCO).

7. The method of claim 1 , wherein adjusting for phase error comprises:
applying a phase adjustment.

8. The method of claim 1 , wherein the second power mode is a higher power mode than the first power mode.

9. The method of claim 8 , wherein adaptively switching to the second power mode comprises:
switching to a main synthesizer routed to each of a plurality of transmission/reception (Tx/Rx) chains associated with a modem for the second power mode from a plurality of local synthesizers routed respectively to one of the plurality of Tx/Rx chains for the first power mode.

10. The method of claim 1 , wherein adaptively switching to the second power mode also is based on a beam-formed or single user packet that is to be received by the device.

11. The method of claim 1 , wherein adaptively switching to the second power mode also is based on a received signal strength indicator (RSSI), a signal-to-noise ratio (SNR) or a signal-to-interference-plus-noise ratio (SINR) of a packet that is to be received by the device.

12. The method of claim 1 , wherein switching to the second power mode comprises:
switching to the second power mode during receipt of the control information.

13. The method of claim 1 , wherein switching to the second power mode comprises:
switching to the second power mode after receipt of the control information is completed.

14. The method of claim 1 , wherein switching to the second power mode comprises:
switching to the second power mode during receipt of the control information via a physical downlink control channel (PDCCH).

15. The method of claim 1 , wherein switching to the second power mode comprises:
switching to the second power mode after receipt the control information via a PDCCH is completed.

16. The method of claim 1 , wherein the MCS value is an MCS index value.

17. A wireless communication device, comprising:
a receiver configured to receive control information for incoming data in a transmission frame while in a first power mode of the device, the control information including a modulation and coding scheme (MCS) value; and
a power controller configured to:
adjust for phase error before switching to a second power mode to mitigate phase error caused by switching, wherein the adjusting comprises implementing an MCS rate for a transition point between the first power mode and the second power mode, the implemented MCS rate being lower than an MCS rate associated with the second power mode and having error vector magnitude (EVM) constraints that mitigate phase error caused by switching; and
adaptively switch to the second power mode of the device during the transmission frame, wherein the switching is based at least in part on the received MCS value and a bandwidth mode for reception.

18. The device of claim 17 , wherein the receiver is further configured to:
receive incoming data of the transmission frame while in the second power mode.

19. The device of claim 7 , wherein the second power mode is a lower power mode than the first power mode.

20. The device of claim 19 , further comprising:
a main synthesizer routed to each of a plurality of transmission/reception (Tx/Rx) chains associated with a modem for the first power mode; and
a plurality of local synthesizers routed respectively to one of the plurality of Tx/Rx chains for the second power mode, wherein the power controller is configured to adaptively switch to the second power mode by switching from the main synthesizer to the plurality of local synthesizers.

21. The device of claim 17 , wherein the MCS value is an MCS index value.

22. An apparatus for adaptive power control for a wireless communication device, comprising:
means for receiving control information for incoming data in a transmission frame while in a first power mode of the device, the control information including a modulation and coding scheme (MCS) value;
means for adjusting for phase error before switching to a second power mode to mitigate phase error caused by switching, wherein the adjusting comprises implementing an MCS rate for a transition point between the first power mode and the second power mode, the implemented MCS rate being lower than an MCS rate associated with the second power mode and having error vector magnitude (EVM) constraints that mitigate phase error caused by switching; and
means for adaptively switching to the second power mode of the device during the transmission frame, wherein the switching is based at least in part on the received MCS value and a bandwidth mode for reception.

23. The apparatus of claim 22 , wherein the means for receiving is further configured to:
receive incoming data of the transmission frame while in the second power mode.

24. The apparatus of claim 22 , wherein the second power mode is a lower power mode than the first power mode.

25. The apparatus of claim 24 , further comprising:
a main synthesizer routed to each of a plurality of transmission/reception (Tx/Rx) chains associated with a modem for the first power mode; and
a plurality of local synthesizers routed respectively to one of the plurality of Tx/Rx chains for the second power mode, wherein the means for adaptively switching to the second power mode is configured to switch from the main synthesizer to the plurality of local synthesizers to transition the device from the first power m

Assignees

• Qualcomm Inc

Inventors

• Homchaudhuri Sandip
• Husted Paul
• Lee Meelan
• Mehta Srenik
• Shi Kai
• Abdollahi-Alibeik Shahram
• Jia Zhanfeng
• Kasnavi Soraya
• Zhang Ning
• Su David Kuochieh
• Thandaveswaran Subramania Sharma
• Gainey Kenneth
• O'Donnell Ian David

Classifications

• G06F1/3278

  Power saving in modem or I/O interface · CPC title

• H04W52/0229 Primary

  where the received signal is a wanted signal · CPC title

• Y02B60/50

  Cross-Sectional Technologies · mapped topic

• G06F1/3293 Primary

  by switching to a less power-consuming processor, e.g. sub-CPU · CPC title

• G06F1/3287

  by switching off individual functional units in the computer system · CPC title