Method, apparatus, and system for wireless writing tracking

A wireless device of a wireless writing tracking system, comprising:

• a processor;
• a memory communicatively coupled to the processor;
• and
• a receiver communicatively coupled to the processor, wherein:
• an additional wireless device of the wireless writing tracking system is configured for transmitting a first wireless signal through a wireless multipath channel of a venue,
• the receiver is configured for receiving a second wireless signal through the wireless multipath channel,
• the second wireless signal comprises a reflection of the first wireless signal by a tip of a writing instrument in the venue, and
• the processor is configured for:
• obtaining a time series of channel information (CI) of the wireless multipath channel based on the second wireless signal, wherein each CI comprises at least one of:
• a channel state information (CSI), channel impulse response (CIR), channel frequency response (CFR), or received signal strength index (RSSI), and
• tracking a movement of the tip of the writing instrument based on the time series of CI (TSCI).

A method of a wireless writing tracking system, comprising:

• transmitting a first wireless signal through a wireless multipath channel of a venue;
• receiving a second wireless signal through the wireless multipath channel, wherein the second wireless signal comprises a reflection of the first wireless signal by a tip of a writing instrument in the venue;
• obtaining a time series of channel information (CI) of the wireless multipath channel based on the second wireless signal, wherein each CI comprises at least one of:
• a channel state information (CSI), channel impulse response (CIR), channel frequency response (CFR), or received signal strength index (RSSI);
• and
• tracking a writing of the tip of the writing instrument based on the time series of CI (TSCI).