Reducing listen mode power consumption of a wireless local area network (wlan) device

Abstract

This disclosure provides methods, devices and systems for reducing power consumption when a station (STA) is operating in a listen mode. In some aspects, to reduce power consumption in the listen mode, the STA may alternate between monitoring a wireless channel for packets and not monitoring the wireless channel. When the STA is monitoring the wireless channel for packets in the listen mode, the STA may configure packet detection components to a power-on state. When the STA is not monitoring the wireless channel in the listen mode, the STA may configure packet detection components to a power-off state. During the power-on state of the listen mode, the STA may detect a preamble of a packet that was transmitted over the wireless channel. In response to detecting the preamble of the packet, the STA may switch from the listen mode to a receive mode to process the packet.

What is claimed is: 
     
         1 . A method for wireless communications in a wireless local area network (WLAN) performed by a first WLAN device, comprising:
 alternating, during a listen mode, one or more components of the first WLAN device between a power-off state of the listen mode and a power-on state of the listen mode of the first WLAN device in accordance with a duty cycle; and   receiving, during the power-on state of the listen mode, preamble information of a packet from a second WLAN device.   
     
     
         2 . The method of  claim 1 , wherein alternating the one or more components between the power-off state of the listen mode and the power-on state of the listen mode includes:
 alternating, during the listen mode when the first WLAN device is monitoring a wireless channel for packets, the one or more components between the power-off state of the listen mode and the power-on state of the listen mode.   
     
     
         3 . The method of  claim 1 , wherein a preamble of the packet includes a quantity of repetitions of the preamble information, the method further comprising:
 detecting the preamble information by detecting one or more repetitions of the quantity of repetitions of the preamble information.   
     
     
         4 . The method of  claim 3 , wherein the quantity of repetitions of the preamble information includes a quantity of repetitions of short training field (STF) information. 
     
     
         5 . The method of  claim 3 , wherein a duration of the power-off state of the listen mode and a duration of the power-on state of the listen mode are based at least in part on the quantity of repetitions of the preamble information and a duration of time for detection of the preamble of the packet. 
     
     
         6 . The method of  claim 1 , wherein alternating the one or more components of the first WLAN device between the power-off state of the listen mode and the power-on state of the listen mode is performed when a received signal strength indicator (RSSI) is greater than an RSSI threshold. 
     
     
         7 . The method of  claim 1 , wherein alternating the one or more components of the first WLAN device between the power-off state of the listen mode and the power-on state of the listen mode is performed when a received signal strength indicator (RSSI) is greater than a first RSSI threshold and less than a second RSSI threshold. 
     
     
         8 . The method of  claim 1 , wherein the one or more components of the first WLAN device include at least one of:
 a radio frequency (RF) front end;   an analog-to-digital converter (ADC); or   a baseband processing unit.   
     
     
         9 . The method of  claim 1 , further comprising:
 performing match filtering on the preamble information to detect a preamble of the packet.   
     
     
         10 . The method of  claim 9 , wherein the match filtering is performed on the preamble information during the power-on state. 
     
     
         11 . The method of  claim 1 , further comprising:
 entering a sleep mode in response to a time duration without receiving the packet or expecting to receive the packet being greater than a threshold duration.   
     
     
         12 . The method of  claim 11 , further comprising:
 in response to entering the sleep mode, ceasing monitoring of a wireless channel, and ceasing providing power to the one or more components during the sleep mode.   
     
     
         13 . The method of  claim 11 , further comprising:
 transmitting, to the second WLAN device, an indication of entry into the sleep mode by the first WLAN device prior to entry into the sleep mode by the first WLAN device.   
     
     
         14 . The method of  claim 1 , further comprising:
 monitoring for a preamble of the packet while operating in the power-on state of the listen mode using the preamble information in response to detecting the preamble information.   
     
     
         15 . A first wireless local area network (WLAN) device for wireless communication, comprising:
 one or more processors; and   one or more memories coupled with the one or more processors, the one or more processors configured to cause the first WLAN device to:
 alternate, during a listen mode, one or more components of the first WLAN device between a power-off state of the listen mode and a power-on state of the listen mode of the first WLAN device in accordance with a duty cycle; and 
 receive, during the power-on state of the listen mode, preamble information of a packet from a second WLAN device. 
   
     
     
         16 . The first WLAN device of  claim 15 , wherein alternation of the one or more components between the power-off state of the listen mode and the power-on state of the listen mode comprises the one or more processors configured to cause the first WLAN device to:
 alternate, during the listen mode when the first WLAN device is monitoring a wireless channel for packets, the one or more components between the power-off state of the listen mode and the power-on state of the listen mode.   
     
     
         17 . The first WLAN device of  claim 15 , wherein a preamble of the packet includes a quantity of repetitions of the preamble information, and wherein the one or more processors are further configured to cause the first WLAN device to:
 detect the preamble information by detection of one or more repetitions of the quantity of repetitions of the preamble information.   
     
     
         18 . The first WLAN device of  claim 17 , wherein the quantity of repetitions of the preamble information includes a quantity of repetitions of short training field (STF) information. 
     
     
         19 . The first WLAN device of  claim 17 , wherein a duration of the power-off state of the listen mode and a duration of the power-on state of the listen mode are based at least in part on the quantity of repetitions of the preamble information and a duration of time for detection of the preamble of the packet. 
     
     
         20 . A non-transitory computer-readable medium having stored therein instructions which, when executed by one or more processors of a first wireless local area network (WLAN) device, cause the first WLAN device to:
 alternate, during a listen mode, one or more components of the first WLAN device between a power-off state of the listen mode and a power-on state of the listen mode of the first WLAN device in accordance with a duty cycle; and   receive, during the power-on state of the listen mode, preamble information of a packet from a second WLAN device.