Maximum Achievable Constrained Power Efficiencies of MPPM- QAM Techniques

The maximum achievable power efficiency of a multipulse pulse-position modulation-L-ary quadrature-amplitude modulation (MPPM-LQAM) technique under a constraint on its spectral efficiency is obtained. Variations to this technique that include polarization multiplexing and switching are considered as well. A simple characterization to the maximum achievable power efficiency is derived under the above constraint. Our results are compared with that of traditional QAM techniques under same constraints. The results reveal that at spectral efficiency constraints of 1.5, 2.5, and 3.5 bit/sym/pol, the power efficiency of MPPM-LQAM technique is better than that of traditional QAM technique by ~3.9, 2.2, and 1.4 dB, respectively.