Communication process and system for high-sensitivity and synchronous demodulation signals

A communication process for high-sensitivity and synchronous demodulation signals in a communication system, which comprises at least one transmitter for transmitting a pseudo-periodic chirp-type signal of period T and at least one receiver to receive the chirp signal, wherein the transmitter comprises a local oscillator of the transmitter to generate a chirp signal to be transmitted and the receiver comprises a local oscillator of the receiver suitable for generating an oscillating signal for the frequency conversion of the received chirp signal by a mixer to supply an intermediate signal,

• wherein the process comprises a synchronization phase followed by a modulation or demodulation phase of a data signal,
• wherein the synchronization phase, the transmitter transmits a chirp signal, which in each period T of linear frequency variation is composed of a first cycle portion with a positive slope of linear frequency variation and a second successive cycle portion with a negative slope of linear frequency variation,
• wherein the receiver receives the chirp signal and converts the frequency of this chirp signal in the mixer by means of the oscillating signal generated by the local oscillator of the receiver in order to produce the intermediate signal, wherein the frequency of the oscillating signal is constant so that the frequency variation of the intermediate signal is the image of the frequency variation of the chirp signal,
• wherein a filtered and sampled intermediate signal is supplied to a logic unit of the receiver, which comprises an assembly of m pairs of discrete Fourier transform blocks arranged for an operation in parallel and phase-shifted in relation to one another, where m is a whole number higher than or equal to 1, wherein a first block of each pair is intended for the acquisition in relation to the positive slope of frequency variation of the chirp signal, whereas a second block of each pair is intended for the acquisition in relation to the negative slope of frequency variation of the chirp signal, and
• wherein a processing unit of the logic unit receives the result of each discrete Fourier transform of the pairs of the assembly following at least one acquisition of the chirp signal and determines a frequency and/or a phase error between the transmitter and the receiver on the basis of two peaks detected by at least one pair of the assembly above a defined noise threshold to synchronize the receiver before the demodulation phase of the data.