Abstract: A station (STA) in a wireless network. The STA is configured to cause receiving, from a target STA, information associated with a first anchor point (AP) and model training; transmitting, to the first AP, a first request that first AP perform a first ranging with two or more other APs; receiving, from first AP, first ranging data that include location information for first AP; determining a location of first AP based on the first ranging data; training a first model based on the information associated with model training and the location of first AP; transmitting, to first AP, a second request that first AP perform a second ranging with target STA; receiving, from first AP, second ranging data including movement information of target STA; and determining a first predicted position for target STA based on the second ranging data and the trained first model.

Abstract: An orthogonal frequency-division multiple access (OFDMA)-based backscatter system is provided, including an analog portion and a digital logic portion. The analog portion includes an antenna, radio frequency switches, an envelope detection circuit, and a transmission line. The digital logic portion includes an inverse discrete Fourier transform (IDFT)-based digital frequency synthesis module. Two outputs of the digital logic portion control all of the radio frequency switches, and the envelope detection circuit provides an input of the digital logic portion. OFDMA backscatter tags designed can operate on any given subchannel without hardware being re-powered and modified, and can operate at a specified symbol rate. The system provides a networking physical layer foundation for a large amount of OFDMA backscatter tags, and satisfies the growing Internet of Things capacity requirements.

Abstract: An orthogonal frequency-division multiple access (OFDMA)-based backscatter system is provided, including an analog portion and a digital logic portion. The analog portion includes an antenna, radio frequency switches, an envelope detection circuit, and a transmission line. The digital logic portion includes an inverse discrete Fourier transform (IDFT)-based digital frequency synthesis module. Two outputs of the digital logic portion control all of the radio frequency switches, and the envelope detection circuit provides an input of the digital logic portion. OFDMA backscatter tags designed can operate on any given subchannel without hardware being re-powered and modified, and can operate at a specified symbol rate. The system provides a networking physical layer foundation for a large amount of OFDMA backscatter tags, and satisfies the growing Internet of Things capacity requirements.