A Multiple Access Approach for Faster-than-Nyquist GFDM Systems

Sixth-generation (6G) mobile networks is expected to revolutionize wireless connectivity, paving the way for the Internet of Everything (IoE) and enabling seamless communication between devices, people, and organizations. Advanced techniques, such as non-orthogonal multiple access (NOMA), massive multiple input multiple output (MIMO), and millimeter wave (mmWave) are proposed to deliver high data rates and increase the capacity and spectral efficiency of ultra-dense device networks. However, in scenarios like enhanced remote area communications (eRAC), the use of sub-gigahertz frequencies and TV white spaces (TVWS) is essential to provide Internet services in rural and remote areas, making these advanced techniques impractical. In this context, this paper proposes a new multiple access approach based on the faster-than-Nyquist generalized frequency division multiplexing (FTN-GFDM) waveform to improve user throughput and network capacity in remote areas. Resources in the FTN-GFDM time-frequency grid are allocated with the goal of avoiding inter-user interference (IUI) caused by signal overlap in the time or frequency domains, enabling equalization and detection of user signals without loss of bit error rate (BER) performance. This paper exploits resource allocation strategies and uplink and downlink scenarios for faster-than-Nyquist generalized frequency division multiple access (FTN-GFDMA) schemes, evaluating the effects of interference on BER performance and detection complexity.