5G Wireless Communications With High Mobility

R. He, F. Bai, G. Mao, J. H?rri and P. Ky?sti, "Guest Editorial 5G Wireless Communications With High Mobility," in IEEE Journal on Selected Areas in Communications, vol. 38, no. 12, pp. 2717-2722, Dec. 2020, doi: 10.1109/JSAC.2020.3005498.

Abstract: The fifth generation (5G) wireless communication networks are expected to support communications with high mobility, e.g., with a speed up to 500 km/h. Hence 5G communications will have numerous applications in high mobility scenarios, such as high speed railways (HSRs), vehicular ad hoc networks, and unmanned aerial vehicles (UAVs) communications [1]–[3]. The 5G systems will provide advanced communication platforms enabling reliable transmission for the Wireless Train Backbone (WLTB) or Wireless Train Control & Management System (WTCMS) [4], [5]. They will also enable new services or enhancements for vehicular communications in Intelligent Transportation System (ITS) [6]–[9]. The coordination and swarming control for UAVs will also benefit from 5G capabilities, as UAV-based 5G infrastructure modeling and improvement have begun receiving attention [10].

In general, high mobility communication is not only about how large is the maximum speed, it is more about the challenges caused by mobility. In high mobility scenarios, a wireless channel is rapidly time varying, Doppler shifts and spreads can be much larger than those in cellular communications, and if modeled statistically, the channel will be non-wide-sense stationary (non-WSS) over a short time period. In addition, network topology can change quickly, and switching among base stations (BSs) and/or peer nodes can be more frequent, not forgetting 5G challenges in cross-border mobility [11].

URL: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9264834&isnumber=9264774

J. Wang, C. Jiang, L. Kuang and B. Yang, "Iterative Doppler Frequency Offset Estimation in Satellite High-Mobility Communications," in IEEE Journal on Selected Areas in Communications, vol. 38, no. 12, pp. 2875-2888, Dec. 2020, doi: 10.1109/JSAC.2020.3005497.

Abstract: Satellite communication systems are able to provide diverse services for ground terminals in ubiquitous global coverage, which play a vital role in high-mobility communication environments. Existing technologies developed primarily for satellite communications cannot be readily applied to satellite high-mobility communication scenarios, since high Doppler frequency offset caused by the fast movement of wireless terminals, and low signal-to-noise ratio (SNR) circumstances caused by limited link budgets in satellites incur more difficulty of the synchronization, especially for short burst transmission.

To solve such a problem in satellite high-mobility communications, we propose a novel method named GP-MASO-MLE, which consists of a coarse estimation algorithm based on the Gaussian process (GP) model and Newton-Raphson method, and a fine correction algorithm based on the improved maximum likelihood estimation (MLE) jointly with turbo decoding iterations. Simulation results show that the proposed algorithm can approach to the bit error rate (BER) performance bound of ideal Doppler frequency offset correction within 0.1 dB, which can be well applied in code-aided (CA) satellite high-mobility communication systems for its good performance. In addition, the computational complexity of the proposed algorithm is lower than other traditional turbo synchronization algorithms.

keywords: {Doppler effect;Synchronization;Frequency estimation;Decoding;Satellites;Signal to noise ratio;Satellite communication;Large Doppler frequency offset;satellite high-mobility communications;short burst transmission;Gaussian process model;turbo codes;low SNR},

URL: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9130081&isnumber=9264774