Low power wireless communication system employing magnetic control zones

摘要

A cordless headset, requiring very low power using Time Variant Modulation (TVM) for reception of a magnetic signal and TVM of RF or infrared as the transmitter. The headset area or zone of operations is defined by the magnetic field that the headset operates within and uses a handshake protocol that takes advantage of the TVM fixed clock period. The headset communicates with a base station that includes a TVM transmitter and loop for transmitting a TVM signal to the cordless headset, and a RF or infrared receiver capable of receiving TVM signals from the headset. The base station also contains the headset protocol logic for controlling the headset transmission. The headset and base station receiver can both be fixed, mobile or portable and vary with respect to orientation and distance from each other. The receiver circuits in both base station and headset automatically adjust to the variance in signal strength.