Multiband Wake Up Radio Scheduling for WLAN Power Efficiency
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Solution Overview
Problem
Wireless local area network (WLAN) devices with limited power supplies, such as IoT devices, face rapid battery exhaustion due to the need for continuous operation of WLAN receiver circuits, and existing wake-up mechanisms are inefficient in communicating wake-up signals to multiple devices simultaneously in a spectrum-efficient manner.
Innovation Solution
The implementation of a multiband Wake Up Radio (WUR) system that allows a single access point to send unique WUR frames using the same data unit to multiple stations, utilizing a multiband frame format with concurrent WUR frames separated by guard bands and edge bands, optimized for low-power decoding at WUR circuits, and employing waveform coding to minimize inter-symbol interference and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If WLAN receiver circuit operates continuously to ensure reliable communication, then communication reliability is improved, but power consumption increases rapidly
Solution Approach 1:
The patent segments the communication function into two distinct circuits: a low-power Wake-Up Radio (WUR) circuit for receiving wake-up signals and a main WLAN receiver circuit for full communication operations. This segmentation allows the main receiver to remain off during idle periods while the WUR circuit continuously monitors for wake-up signals, thus maintaining communication reliability while dramatically reducing power consumption.
2Adaptability or versatility
If wake-up signals are sent to multiple devices using traditional single-band methods, then device wake-up capability is improved, but spectrum efficiency deteriorates
Solution Approach 1:
The patent transitions from single-band wake-up signaling to multiband wake-up signaling by dividing the frequency spectrum into multiple sub-bands. Each sub-band can carry independent wake-up signals to different devices simultaneously. This dimensional expansion in frequency space allows multiple devices to be awakened without increasing time duration or sacrificing spectrum efficiency, as each sub-band operates independently.
3Productivity
If multiband WUR frames are transmitted to multiple stations simultaneously, then productivity is improved, but inter-symbol interference increases
Solution Approach 1:
The patent segments the frequency spectrum into multiple non-overlapping sub-bands separated by guard bands. Each sub-band carries wake-up signals for specific devices independently. This frequency-domain segmentation prevents inter-symbol interference between signals intended for different devices, as the guard bands act as protective barriers that isolate adjacent sub-bands from each other.
Solution Approach 2:
The patent applies different characteristics to different parts of the frequency spectrum by assigning specific sub-bands to different devices or signal types. Each sub-band is optimized for its specific purpose with appropriate modulation and coding schemes, while guard bands provide localized protection against interference. This local optimization minimizes inter-symbol interference while maintaining high wake-up signaling productivity.
Data Source
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AI summary
Methods and systems for waking up a wireless receiving stations having wake-up radio (WUR) circuits. A method of providing a wake-up signal in a communications channel for a plurality of receiving stations, comprising: generating a plurality of series of waveform coded symbols, each series being incorporated into a respective wake-up-radio (WUR) frame that is intended for a respective receiving station and has a respective predefined bandwidth; combining the respective WUR frames into a multiband WUR data unit having a bandwidth that is greater than a sum of the predefined bandwidths of the wake-up radio frames; transmitting a wake-up signal including the multiband WUR data unit in the communications channel.