A Cyclic Prefix Free Multiple Input Multiple Output Generalized Frequency Division Multiplexing System Design

The existing generalized frequency division multiplexing (GFDM) systems employ cyclic prefix (CP) to avoid inter-symbol interference (ISI) in frequency-selective fading channels. For multiple input multiple output GFDM (MIMO-GFDM) system, the existence of CP will result in the losses of spectrum efficiency, energy efficiency and transmission rate (SET). In this paper, we propose a novel MIMO-GFDM system without CP insertion. We design a decision feedback equalizer that is performed before fast Fourier transform operation to efficiently remove ISI. We also design a CP restoration unit to remove the inter-carrier interference in the MIMO-GFDM systems. The proposed CP-free MIMO-GFDM system offers a much higher SET than traditional MIMO-GFDM systems in frequency selective fading channels. Some simulation examples are given to demonstrate the effective of the proposed MIMO-GFDM system.