Wavelet-Based Three-Dimensional OTFS With Dual-Mode Index Modulation

In this letter, we propose a new transmission scheme for the next-generation wireless communications called wavelet-based three-dimensional orthogonal time frequency space with dual-mode index modulation (W-3D-OTFS-DM-IM). To enhance the spectral efficiency, the transmitted information bits are mapped into the OTFS frame in the delay-doppler domain using a dual-mode index modulation with 3D signal constellations. The wavelet transform instead of the conventional Fourier transform is applied to achieve OTFS modulation for reduction of complexity and improvement of error performance. The Mallat algorithm is exploited to form the wavelet transform matrix. Simulation results show that the proposed W-3D-OTFS-DM-IM has obviously better bit error rate (BER) performance and spectral efficiency than the reference systems in the high-mobility communication scenarios.