METHOD FOR TRANSMITTING AND RECEIVING QUADRATURE AMPLITUDE MODULATION SIGNALS, A SYSTEM FOR CARRYING OUT SAID METHOD, A MACHINE-READABLE CARRIER AND THE USE OF A METHOD FOR SYNCHRONOUSLY RECEIVING QUADRATURE AMPLITUDE MODULATION SIGNALS

摘要

The invention relates to signal transmission. The use of the invention for transmitting and receiving quadrature amplitude modulation signals on unlicensed frequency bands makes it possible to lower a demodulation threshold owing to a low synchronisation threshold. The inventive method consists in extending a burst of M m-level quadrature amplitude modulation signals with the aid of two pseudo-random sequences, one of which is periodically inverted in some bursts, thereby making it possible to extract, on a receiving side, the quadrature amplitude modulation signal components corresponding to a meander signal of the pseudo-random sequence inversion (the frequency of which is known). The inventive method is carried out by means of a corresponding system in a hardware and software mode. Moreover, said method can be used for synchronising the reception of quadrature amplitude modulation signals.