Multi-user (MU) wake-up signal transmission by using FDMA scheme in WLAN

Patent metadata

Field	Value
Publication number	US-10470125-B2
Application number	US-201715852548-A
Country	US
Kind code	B2
Filing date	Dec 22, 2017
Priority date	Dec 22, 2016
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

Systems and methods of transmitting a multi-user (MU) wake-up packet in WLAN including wake-up signals to activate main radios on multiple communication devices via the wake-up radios (WURs). In the multi-user wake-up packet, a frequency channel can be divided into several sub-channels for transmitting multiple wake-up signals in FDMA. Each wake-up signal is modulated in ON/OFF Key modulation. Two adjacent wake-up signals are adequately spaced apart by a certain frequency spacing to reduce adjacent channel interferences. Once a WUR on a receive device receives the packet, it generates a wake-up indication to wake up the main radio for active data communication. The MU wake-up packet may also include a sequence of multiple wake-up signals transmitted using the same sub-channel and cascaded in a time-domain. A reconfiguration window may be inserted between consecutive wake-up signals on the same sub-channel, and between a legacy preamble and the following wakeup signals.

First claim

What is claimed is:

1. A method of wireless communication, said method comprising,
generating a packet comprising a first plurality of wake-up radio signals, wherein said generating comprises:
allocating a sub-channel of a first frequency channel to each of said first plurality of wake-up radio signals; and
modulating said first plurality of wake-up radio signals using On/OFF Key (OOK) modulation, wherein each of said first plurality of wake-up radio signals is operable to activate a main radio resident in a respective wireless communication device of a first plurality wireless communication devices; and

transmitting said packet by using Frequency-Division Multiple Access (FDMA), wherein said first plurality of wake-up radio signals in said packet are transmitted through different sub-channels of said first frequency channel, and wherein further each of said first plurality of wake-up radio signals is transmitted through a corresponding sub-channel of said first frequency channel.

2. The method of claim 1 , wherein a frequency spacing between sub-channels of each two adjacent wake-up radio signals of said first plurality of wake-up radio signals equals a bandwidth of a sub-channel allocated to a wake-up radio signal, and wherein further sub-channels at upper and lower ends of the first frequency channel are unused.

3. The method of claim 1 , wherein said first frequency channel has a bandwidth of approximately 20 MHz, wherein further each of said first plurality of wake-up radio signals is allocated with a bandwidth of approximately 4 MHz.

4. The method of claim 1 , wherein said packet further comprises a second plurality of wake-up radio signals operable to activate main radios resident in a second plurality of wireless communication devices, respectively, wherein said generating said packet further comprises allocating a sub-channel of a second frequency channel to each of said second plurality of wake-up radio signals, and wherein further each of said second plurality of wake-up radio signals is transmitted through a corresponding sub-channel of said second frequency channel.

5. The method of claim 1 , wherein said packet further comprises a legacy preamble operable to prevent a legacy device from transmitting signals during transmission of said packet, and wherein said legacy preamble is transmitted through said first frequency channel, wherein said generating said packet further comprises inserting a reconfiguration window between said legacy preamble and a wake-up radio signal, and wherein further said reconfiguration window corresponds to a transient period for a transmitter to switch from waveform generation for said legacy preamble to waveform generation for said wake-up radio signal.

6. The method of claim 1 further comprising generating another packet comprising a single wake-up radio signal operable to activate a wireless communication device of said first plurality of wireless communication devices, and wherein further said single wake-up radio signal is transmitted through an allocated sub-channel of said first frequency channel.

7. The method of claim 1 , wherein said packet further comprises a second wake-up radio signal operable to activate a main radio resident in a third plurality wireless communication devices, respectively, wherein a first wake-up radio signal of said first plurality of wake-up radio signals and said second wake-up radio signal are allocated with a same sub-channel and transmitted in a cascaded sequence in a time domain.

8. The method of claim 1 , wherein said packet further comprises a data field directed to another wireless communication device, and wherein further said generating said packet further comprises modulating said data field by using Orthogonal Frequency-Division Multiple Access (OFDMA) modulation.

9. The method of claim 1 further comprising:
generating another packet comprising a third plurality of wake-up radio signals, wherein said generating comprises:
allocating a sub-channel of a respective frequency channel of a plurality of frequency channels to each of said third plurality of wake-up radio signals, wherein each of said plurality of frequency channels has a bandwidth equal to or greater than 20 MHz, and wherein said sub-channel of said respective frequency channel has a bandwidth of 4 MHz; and
modulating said third plurality of wake-up radio signals using On/OFF Key (OOK) modulation; and

transmitting said another packet by using FDMA.

10. A wireless communication device comprising:
a memory:
a processor coupled to the memory; and
transceiver coupled to said memory, wherein said transceiver is configured to generate a packet comprising first plurality of wake-up radio signals by performing:
allocating a sub-channel of a first frequency channel to each of said first plurality of wake-up radio signals; and
modulating said multiple wake-up radio signals using On/OFF key (OOK) modulation, wherein each of said first plurality of wake-up radio signals is operable to activate a main radio resident in a respective wireless communication device of a first plurality wireless communication devices; and

a transceiver configured to transmit said packet by using Frequency-Division Multiple Access (FDMA), wherein said first plurality of wake-up radio signals in said packet are transmitted through different sub-channels of said first frequency channel, and wherein further each of said first plurality of wake-up radio signals is transmitted through a corresponding sub-channel of said first frequency channel.

11. The wireless communication device of claim 10 , wherein a frequency spacing between each two adjacent wake-up radio signals of said first plurality of wake-up radio signals equals a bandwidth of a sub-channel allocated to a wake-up radio signal.

12. The wireless communication device of claim 10 , wherein said packet further comprises a second plurality of wake-up radio signals operable to activate main radios resident in a second plurality wireless communication devices, respectively, wherein said transceiver is further configured to allocate a sub-channel of said second frequency channel to each of said second plurality of wake-up radio signals, and wherein further each of said second plurality of wake-up radio signals is transmitted through a corresponding sub-channel of said second frequency channel.

13. The wireless communication device of claim 10 , wherein said packet further comprises a legacy preamble operable to prevent a legacy device from transmitting signals during transmission of said packet, and wherein said legacy preamble is transmitted through said first frequency channel, wherein said transceiver is further configured to insert a reconfiguration window between said legacy preamble and a wake-up radio signal, wherein said reconfiguration window corresponds to a resettlement period of a transmitter that transmits said packet.

14. The wireless communication device of claim 10 , wherein said transceiver is further configured to generate another packet comprising a single wake-up radio signal operable to activate a wireless communication device of said plurality of wireless communication devices, and wherein further said single wake-up radio signal is transmitted through an allocated sub-channel of said first frequency channel.

15. The wireless communication device of claim 10 , wherein said packet further comprises a second wake-up radio signal operable to activate a main radio resident in a third plurality wireless communication devices, respectively, wherein a first wake-up radio signal of said first plurality of wake-up radio signals and said sec

Assignees

• Mediatek Inc

Inventors

• Liu Jianhan
• Pare Jr Thomas Edward
• Fong Keng Leong

Classifications

• H04W84/12

  WLAN [Wireless Local Area Networks] · CPC title

• H04W74/006

  in the downlink, i.e. towards the terminal · CPC title

• H04W52/0219

  where the power saving management affects multiple terminals · CPC title

• H04L27/10

  Frequency-modulated carrier systems, i.e. using frequency-shift keying (H04L27/32 takes precedence) · CPC title

• H04W52/0235 Primary

  where the received signal is a power saving command · CPC title