COMMUNICATION SYNCHRONIZATION

摘要

Aspects of the present disclosure provide communications between local and remote devices having low-frequency (LF) and high-frequency (HF) circuits. As may be implemented in accordance with one or more embodiments, the local device transmits an LF signal to the remote device, which synchronizes its clock based on the LF signal. Another LF signal is communicated from the local device to the remote device using a reduced quality factor, which can be implemented to facilitate synchronization. The clock is resynchronized based on the second LF signal and used to transmit an HF signal with a time delay. The local device synchronizes its clock based on the HF signal, and transmits another HF signal to the remote device using the clock and another time delay. The remote device re-synchronizes its clock based on the second HF signal while accounting for a trip time for communicating the first and/or second HF signals.

主权项

1. A method for communicating between a local device having a low-frequency (LF) transmitter and a high-frequency (HF) transceiver, and a remote device having an LF receiver and an HF transceiver, the method comprising:
transmitting a first LF signal from the local device to the remote device; at the remote device, synchronizing a first clock based on the first LF signal; after transmitting the first LF signal, transmitting a second LF signal from the local device to the remote device using the synchronized first clock, and processing the second LF signal with a reduced quality factor at the local and remote devices, therein facilitating detection of the second LF signal at the remote device with reduced phase ambiguity; at the remote device, re-synchronizing the first clock based on the processed second LF signal, and using the re-synchronized first clock to transmit a first HF signal with a first predetermined time delay, relative to receipt of one of the first and second LF signals; at the local device, synchronizing a second clock based on the first HF signal, and transmitting a second HF signal to the remote device using the second clock and a second predetermined time delay, relative to receipt of the first HF signal at the local device; and at the remote device, re-synchronizing the first clock based on the second HF signal and while accounting for a trip time for at least one of: communicating the first HF signal from the remote device to the local device, and communicating the second HF signal from the local device to the remote device.