Low-Complexity 6G Reference Design Employing Non-Orthogonal GFDM–MIMO Interference Cancellation Technique

Abstract

Anticipated scenarios for Sixth Generation (6G) mobile communications emphasize global connectivity, particularly for enhanced Remote Area Communications (eRAC). This paper proposes a high-data-rate Generalized Frequency Division Multiplexing (GFDM) transceiver reference design employing Spatial Multiplexing (SM)-Multiple-Input-Multiple-Output (MIMO) and iterative Minimum Mean Squared Error (MMSE)-Parallel Interference Cancellation (PIC) detection tailored for spectrum sharing in TV White Space (TVWS) scenarios. We introduce a novel system matrix permutation strategy that facilitates the decoupling of the GFDM-MIMO system into smaller and more manageable subsystems. This approach significantly reduces computational complexity while maintaining the high spectral efficiency and low Out-of-Band (OOB) emissions inherent to non-orthogonal waveforms. Unlike previous works, this reference design provides a scalable nonlinear receiver architecture for high-dimensional MIMO systems, evaluated through both theoretical complexity analysis and extensive simulations under realistic Clustered Delay Line (CDL) channel conditions.