A Comparison of OFDM and GFDM-Based MFSK Modulation Schemes for Robust IoT Applications

Orthogonal Frequency Division Multiplexing based M-ary Frequency Shift Keying (OFDM-MFSK) is a non- coherent modulation scheme that was proposed for robust transmission over fast fading environments. It combines the MFSK modulation scheme with OFDM. In this paper, the Generalised Frequency Division Multiplexing (GFDM) waveform is considered to use with MFSK to take the advantages of the low out of band radiation and relaxed synchronisation requirements. Different methods to combine MFSK and GFDM are proposed and their performances are evaluated and compared with OFDM-MFSK. The mixed sub-carrier and sub-symbol method, which is one of the proposed methods, is the most promising technique. Additionally, gain margin is also seen for MFSK modulation scheme compared to ordinary OFDM or GFDM. This gain can be used to radically improve the performance for some 5G applications, such as IoT, at low Signal to Noise Ratio (SNR) values.