Energy and Spectrally Efficient Signalling for Next Generation IoT

This work proposes an energy and spectrally efficient signalling technique for the next generation internet of things (IoT). The signalling method employs the bandwidth compressed fast-orthogonal frequency division multiplexing (FOFDM) scheme with the single dimensional pulse amplitude modulation (PAM) as well as the frequency orthogonal filtering technique using Hilbert transform (HT) pair. The proposed HT-FOFDM system is designed and modelled based on the narrowband IoT (NB-IoT) specifications. To investigate the designed signalling method of different spectral efficiencies, we conducted simulations for HT-FOFDM with comparisons to single-carrier frequency division multiple access (SC-FDMA). We show that the proposed PAM modulated HT-FOFDM signalling increases the data rate effectively while maintaining reliable transmission within the same bandwidth of 180kHz. Comparative results of the bit error rate (BER) performance in additive white Gaussian noise (AWGN) channel and constellation diagrams of received noisy signals are presented. Furthermore, we show that HT-FOFDM with PAM modulation schemes comprehensively outperforms SC-FDMA that achieves the same spectral efficiencies with significant power advantages.