4. THz transmission links

4.1 Modulation and performance indicators for a THz communication link

In the THz range, various approaches have been followed, coming from microwave domains, long-distance optical communications, coherent optical communications, and even more conventional radio domains. As a result, digital amplitude modulations and phase/amplitude vector modulations (QPSK, QAM-16, QAM-32 and beyond) are used.

Remember that the main advantage of vector modulation is to optimize bandwidth with the highest possible spectral efficiency (bit/s/Hz).