Patent ID: 8743976
Filing Date: 2014-06-03
Classification: H04L

Abstract:
1. A method comprising: detecting at a base a channel impulse response, comprising copies of an impulse-pulse emitted by a remote target, modulated at a first carrier frequency, wherein each copy is received at a different time based on a length of a respective path traveled by the respective copy through a communication channel; obtaining at the base the channel impulse response modulated at an intermediate frequency by combining the detected channel impulse response modulated at the first carrier frequency with a signal generated at the base and having a first frequency, wherein the intermediate frequency is a difference between the first carrier frequency and the first frequency; digitizing at the base the obtained channel impulse response modulated at the intermediate frequency into a channel impulse response waveform; storing at the base the channel impulse response waveform; performing a time-reversal operation on the stored channel impulse response waveform, wherein the time-reversal operation includes adding a time delay, which is determined based on both a time to receive the channel impulse response waveform at the base from the remote target and a time to reverse in the time domain the stored channel impulse response waveform; preparing a data signal comprising a copy of the time reversed channel impulse response waveform corresponding to each bit of a data stream that comprises information to be provided to the remote target; modulating the prepared data signal at a transmission frequency; and transmitting the modulated data signal from the base to the remote target.