TY - JOUR
T1 - OTFS-Based Robust MMSE Precoding Design in Over-the-Air Computation
AU - Zhou, Dongkai
AU - Guo, Jing
AU - Wang, Siqiang
AU - Zheng, Zhong
AU - Fei, Zesong
AU - Yuan, Weijie
AU - Wang, Xinyi
N1 - Publisher Copyright:
© 1967-2012 IEEE.
PY - 2024
Y1 - 2024
N2 - Over-the-air computation (AirComp), as a data aggregation method that can improve network efficiency by exploiting the superposition characteristics of wireless channels, has received much attention recently. Meanwhile, the orthogonal time frequency space (OTFS) modulation can provide a strong Doppler resilience and facilitate reliable transmission for high-mobility communications. Hence, in this work, we investigate an OTFS-based AirComp system in the presence of time-frequency dual-selective channels. In particular, we commence from the development of a novel transmission framework for the considered system, where the pilot signal is sent together with data, and the channel estimation is implemented according to the echo from the access point to the sensor, thereby reducing the overhead of channel state information (CSI) feedback. Hereafter, based on the CSI estimated from the previous frame, a robust precoding matrix aiming at minimizing mean square error in the current frame is designed, which takes into account the estimation error from the receiver noise and the outdated CSI. The simulation results demonstrate the effectiveness of the proposed robust precoding scheme by comparing it with the non-robust precoding. The performance gain is more obvious in a high signal-to-noise ratio in case of large channel estimation errors.
AB - Over-the-air computation (AirComp), as a data aggregation method that can improve network efficiency by exploiting the superposition characteristics of wireless channels, has received much attention recently. Meanwhile, the orthogonal time frequency space (OTFS) modulation can provide a strong Doppler resilience and facilitate reliable transmission for high-mobility communications. Hence, in this work, we investigate an OTFS-based AirComp system in the presence of time-frequency dual-selective channels. In particular, we commence from the development of a novel transmission framework for the considered system, where the pilot signal is sent together with data, and the channel estimation is implemented according to the echo from the access point to the sensor, thereby reducing the overhead of channel state information (CSI) feedback. Hereafter, based on the CSI estimated from the previous frame, a robust precoding matrix aiming at minimizing mean square error in the current frame is designed, which takes into account the estimation error from the receiver noise and the outdated CSI. The simulation results demonstrate the effectiveness of the proposed robust precoding scheme by comparing it with the non-robust precoding. The performance gain is more obvious in a high signal-to-noise ratio in case of large channel estimation errors.
KW - Over-the-air computation
KW - imperfect channel state information
KW - orthogonal time frequency space
KW - robust precoding
UR - http://www.scopus.com/inward/record.url?scp=85189630650&partnerID=8YFLogxK
U2 - 10.1109/TVT.2024.3385445
DO - 10.1109/TVT.2024.3385445
M3 - Article
AN - SCOPUS:85189630650
SN - 0018-9545
VL - 73
SP - 13932
EP - 13937
JO - IEEE Transactions on Vehicular Technology
JF - IEEE Transactions on Vehicular Technology
IS - 9
ER -