A Novel Low Complexity Faster-than-Nyquist (FTN) Signaling Detector for Ultra High-Order QAM

Faster-than-Nyquist (FTN) signaling is a promising non-orthogonal pulse modulation technique that can improve the spectral efficiency (SE) of next generation communication systems at expense higher detection complexity to remove introduced inter-symbol interference (ISI). In this paper, we investigate problem ultra high-order quadrature-amplitude (QAM) FTN where exploit mathematical programming based on alternating directions multiplier method (ADMM). The proposed ADMM sequence estimation (ADMMSE) detector demonstrates an excellent trade-off between performance and computational effort enabling successful SE gains for QAM orders as high 64K (65,536). ADMMSE polynomial in length transmit symbols its sensitivity order increases only logarithmically. Simulation results show 16-QAM, achieves comparable generalized approach semidefinite relaxation-based (GASDRSE) detector, but experimentally evaluated much lower time. additionally starting from 4-QAM, or quadrature phase shift keying (QPSK), up including 64K-QAM when compared conventional Nyquist signaling. very low required makes practically both systems.