double square quadrature (10GbE) (DSQ)
Double Square (DSQ) is a multi-level and multi-angle modulation technique that uses two quadrature amplitude modulation( QAM) offset from each other.
DSQ128 modulation consists of two 64QAM modulations with 128 modulation values organized in 8x8x2 bits. The staggered modulation values distinguish the DSQ modulation from a multilevel pulse amplitude modulation( PAM). The DSQ128 modulation is extremely robust and features a good signal-to- noise ratio( SNR) and is used in the 10GBase-T 10GbEinterface.