A new generation of 90 Mb/s SATCOM systems: bandwidth efficient, field tested 16-QAM

A new generation of 16-QAM (quadrature amplitude modulation) digital satellite broadcast equipment and satellite communications (SATCOM) systems that double the spectral efficiency of currently operational satellite links is described. It is demonstrated that with field-proven 16-QAM systems data transmission at a rate of 90 Mb/s is feasible in a transmission bandwidth of 30 MHz. Extensive operational satellite tests performed over the T-303 satellite of AT&T demonstrated virtually error-free performance, i.e. a BER <10^-10 and no errors for several days. The practical bandwidth efficiency of this new generation of digital SATCOM systems is 3 b/s/Hz, i.e. double the currently used 1.5-b/s/Hz quaternary phase-shift-keying (QPSK) systems. This increased spectral efficiency is expected to lead to new digital TV and digital signal broadcasting applications