Performance Assessment of OTFS Modulation in High Doppler Airborne Communication Networks

Future 6G and emerging 5G mobile networks are anticipated to support high mobility scenarios, such as airborne platforms, unmanned aerial vehicles, and vehicle-to-vehicle communications. In such deployments, communications are severely affected by Doppler shifts, necessitating the use of novel modulation waveforms. It has recently been suggested that orthogonal time frequency space (OTFS) modulation is a suitable technique for handling high Doppler channels. In the two-dimensional delay-Doppler (DD) domain, OTFS transforms a time-varying fading channel into a time-independent channel. In the DD domain, a virtually constant channel with a complicated channel gain is created by multiplexing the transmit symbols. The high Doppler aerial communication network that we examine in this research allows relative mobile node speeds to exceed 1200 m/s. The system under consideration is an example of a mobile ad hoc network, in which mobile nodes in the air can join or exit the network. Additionally, every node has an array of antennas that facilitates directed communication between mobile nodes. Depending on the carrier frequency chosen and the relative speeds of the various airborne platforms, the Doppler shifts in this aerial communication network are between 52 and 72 kHz, and they may be considerably higher. In order to effectively correct for the significant Doppler shifts in the DD domain, OTFS modulation is employed in this work. To demonstrate the capability of OTFS modulation in handling such harsh transmission conditions, a thorough performance evaluation in terms of bit error rate (BER) is carried out.

KEYWORDS: 5G, MANET, OTFS, High Doppler, Airborne communication networks.