Abstract: The present disclosure provides a ranging method by using a first signal transmitted by a first device, and a second signal generated and transmitted by a target device in response to the first signal. The ranging method calculates the distance between the target device and a second device being in communication with the first and target devices, by using: a first time interval from a point in time of first device's transmitting the first signal to a point of receiving first part of the second signal; a second time interval from a point of the second device's receiving the first signal to a point receiving the first part of the second signal; and a delay time interval from a point of the target device's receiving the first signal to a start time of the second signal and a duration of the first part of the second signal.

Abstract: The present disclosure provides a ranging method by using a first signal transmitted by a first device, and a second signal generated and transmitted by a target device in response to the first signal. The ranging method calculates the distance between the target device and a second device being in communication with the first and target devices, by using: a first time interval from a point in time of first device's transmitting the first signal to a point of receiving first part of the second signal; a second time interval from a point of the second device's receiving the first signal to a point receiving the first part of the second signal; and a delay time interval from a point of the target device's receiving the first signal to a start time of the second signal and a duration of the first part of the second signal.

Abstract: A differential orthogonal modulation method and a differential orthogonal modulation apparatus using a repetition time interval difference of a chirp signal are disclosed. Such a differential orthogonal modulation method performed in a transmitter unit of a digital communication system comprises the steps of converting data having a serial bit format to be transmitted in the transmitter unit into a parallel format to create parallel input data, inputting the parallel input data into a symbol mapper, orthogonally modulating the parallel input data inputted into the symbol mapper to create modulated data comprised of differential bi-orthogonal functions, differentially encoding the modulated data to output encoded data, converting the encoded data into a serial bit format to create a baseband signal, and processing the baseband signal to create a transmission signal in a form of a chirp signal having a specific repetition time interval difference.

Abstract: Disclosed is a method and an apparatus for channel estimation regarding electromagnetic wave multi-path characteristics between a sender and a receiver by using a chirp signal.

Abstract: Disclosed is a method and an apparatus for channel estimation regarding electromagnetic wave multi-path characteristics between a sender and a receiver by using a chirp signal.