8-ary modulation with triangular lattice

Abstract

High-order modulation is currently widespread since it increases spectral efficiency and data rate. In case of 8-ary signal set, the 8-ary phase shift keying having a constant envelope is useful but presents a poor performance in terms of power efficiency. In this letter, 8-ary modulation with a triangular lattice is investigated to improve the performance of 8-ary signaling and its power gains are elaborated analytically. According to results, the proposed 8-ary signal set provides the asymptotic power gains of 1.811 dB and 0.218 dB over the conventional 8-ary phase shift keying and quadrature amplitude modulation, respectively.