Polarization-Aware Channel State Prediction Using Phasor Quaternion Neural Networks

The performance of a wireless communication system depends to a large extent on the wireless channel. Due to the multipath fading environment during the radio wave propagation, channel prediction plays a vital role to enable adaptive transmission for wireless communication systems. Predicting various channel characteristics by using neural networks can help address more complex communication environments. However, achieving this goal typically requires the simultaneous use of multiple distinct neural models, which is undoubtedly unaffordable for mobile communications. Therefore, it is necessary to enable a simpler structure to simultaneously predict multiple channel characteristics. In this paper, we propose a fading channel prediction method using phasor quaternion neural networks (PQNNs) to predict the polarization states, with phase information involved to enhance the channel compensation ability. We evaluate the performance of the proposed PQNN method in two different fading situations in an actual environment, and we find that the proposed scheme provides 2.8 dB and 4.0 dB improvements at bit error rate (BER) of $10^{-4}$ , showing better BER performance in light and serious fading situations, respectively. This work also reveals that by treating polarization information and phase information as a single entity, the model can leverage their physical correlation to achieve improved performance.