Back to results
US 10,757,652 B2Granted
Wireless receiver with field capture for beacon frames
AssigneeSilicon Laboratories Inc.
InventorsSriram Mudulodu, Partha Sarathy Murali, SuryaNarayana Varma Nallaparaju, Logeshwaran Vijayan, Subba Reddy Kallam, Venkat Mattela
Life of this patent
Estimating the term…
Abstract
A wireless receiver powers up shortly before the expected arrival of a beacon frame, and upon detection of a beacon frame from an access point the station is associated with and determination of subsequent fields of interest, including at least a TIM field, the receiver powers down. At the previously identified fields of interest, the receiver powers up and uses previously stored values to continue packet demodulation, thereafter examining the TIM field to determine whether the AP has packets to transmit to the station.
Claims15
A wireless receiver for WLAN beacon frames comprising:
- a power controller for coupling a power source to a receiver comprising a preamble detector, a preamble processor, a baseband processor, and a wakeup processor;
- the power controller providing power to a preamble detector upon expected arrival of a beacon frame;
- the preamble detector examining an incoming packet for a preamble and determining the start of a packet and asserting preamble detection by cross correlation of a preamble fragment from the incoming packet with a preamble-generating polynomial output, and using a peak result of the cross correlation to estimate a start of frame to powerup the receiver for extracting fields which follow the preamble fragment;
- upon the assertion of preamble detection, the receiver subsequently determining whether the packet is a beacon packet from an access point the station is associated with;
- upon determination that the packet is a beacon packet from an access point the station is associated with, the wakeup processor determining a wakeup time for the receiver during a TIM field of the beacon frame and putting the receiver into a power down state until the TIM field interval, at which time the receiver is put in a power-up state;
- the baseband processor examining the TIM field of the beacon frame, powering down, and subsequently powering up during an interval indicated by the TIM field to receive packets indicated as available by the TIM field.
3 more elements
A process for packet reception operative on a receiver, the process comprising:
- enabling power to a preamble detector during an interval of expected beacon frame arrival, the preamble detector operative on a segment of a preamble and indicating detection of a preamble, where the preamble detector performs a cross correlation of a fragment of a received preamble with a preamble template generated by a polynomial, the cross correlation indicating a start of frame delimiter, the start of frame delimiter indicating the interval of said TIM field;
- upon detection of a preamble, determining that the received frame is a beacon frame;
- upon determination that the received frame is a beacon frame, determining fields of interest and associated intervals, at least one field of interest being a TIM field;
- powering down the receiver at intervals other than the fields of interest;
- examination of said TIM field of said beacon to determine whether a packet is to be received from a remote station and powering down the receiver;
- if said TIM field indicates a packet is to be received, powering down the receiver until the beacon frame interval has passed, thereafter powering up the receiver and receiving packets associated with the TIM field.
3 more elements
A wireless receiver for WLAN beacon frames comprising:
- a power controller for coupling a power source to a receiver comprising a preamble detector, a preamble processor, a baseband processor, and a wakeup processor;
- the power controller providing power to a preamble detector upon expected arrival of a beacon frame;
- the preamble detector examining an incoming packet for a preamble, the preamble detector operative during a fragment of a preamble, the preamble processor comparing the fragment of preamble to a preamble template sequence, the preamble detector determining an end of preamble time and at least one of the interval for:
- a beacon MAC source address field;
- a beacon frame length field;
- a TIM header field;
- or
- a TIM bitmap field;
- upon detection of a preamble, the receiver subsequently determining whether the packet is a beacon packet from an access point the station is associated with;
- upon determination that the packet is a beacon packet from an access point the station is associated with, the wakeup processor determining a wakeup time for the receiver during a TIM field of the beacon frame and putting the receiver into a power down state until the TIM field interval, at which time the receiver is put in a power-up state;
- the baseband processor examining the TIM field of the beacon frame, powering down, and subsequently powering up during an interval indicated by the TIM field to receive packets indicated as available by the TIM field.
8 more elements
Dependencies are inferred from the claim text.