Optimal Design of UFMC Modulation Waveform in Mobile Internet of Things Communication

‍ ‍Mobile Internet of Things （IoT） communication is a key 6G technology. Because of the variety of terrestrial base station environments， unmanned aerial vehicle （UAV）-assisted communication is considered an important part of IoT communication， and has received widespread attention. Universal filtered multi-carrier （UFMC）， as a new non-orthogonal multi-carrier modulation technology， inherits the advantages of orthogonal frequency division multiplexing and is mainly used in short packet burst communication scenarios. It is considered suitable for next-generation wireless IoT communications. However， in the high-speed moving environment of UAVs， communication signals suffer from a significant Doppler frequency shift， resulting in severe inter-carrier interference （ICI） and degradation in system performance. To alleviate the ICI problem， this study theoretically analyzed and derived the signal to interference plus noise ratio （SINR） of a UFMC system in the presence of Doppler frequency shift. This SINR analysis showed that the ICI resistance of the system could be improved by optimally regulating the passband fluctuation of the UFMC waveform filter， to facilitate its reduction， and by accelerating the transition band attenuation. A mathematical model was constructed for the optimal design of waveform filters to meet UFMC communication requirements， and an interference suppression method based on these optimal waveform filters was constructed. This model could effectively regulate the passband fluctuation of the waveform filter. Traversal search provided waveform filters that enabled a relatively optimal system error rate （SER）. In a system simulation considering a Doppler frequency shift， the SER comparison results showed that the waveform filter designed according to the constraint minimax criterion could effectively suppress the system ICI and improve the SER compared with a UFMC system employing the traditional waveform filter. This provides a reference for the waveform design of a future mobile IoT communication system.