Abstract
Cellular vehicle-to-everything (C-V2X) networks provide a promising solution
to improve road safety and traffic efficiency. One key challenge in such
systems lies in meeting quality-of-service (QoS) requirements of vehicular
communication links given limited network resources, particularly under
imperfect channel state information (CSI) conditions caused by the highly
dynamic environment. In this paper, a novel two-phase framework is proposed to
instill resilience into C-V2X networks under unknown imperfect CSI. The
resilience of the C-V2X network is defined, quantified, and optimized the first
time through two principal dimensions: absorption phase and adaptation phase.
Specifically, the probability distribution function (PDF) of the imperfect CSI
is estimated during the absorption phase through dedicated absorption power
scheme and resource block (RB) assignment. The estimated PDF is further used to
analyze the interplay and reveal the tradeoff between these two phases. Then, a
novel metric named hazard rate (HR) is exploited to balance the C-V2X network's
prioritization on absorption and adaptation. Finally, the estimated PDF is
exploited in the adaptation phase to recover the network's QoS through a
real-time power allocation optimization. Simulation results demonstrate the
superior capability of the proposed framework in sustaining the QoS of the
C-V2X network under imperfect CSI. Specifically, in the adaptation phase, the
proposed design reduces the vehicle-tovehicle (V2V) delay that exceeds QoS
requirement by 35% and 56%, and improves the average vehicle-to-infrastructure
(V2I) throughput by 14% and 16% compared to the model-based and data-driven
benchmarks, respectively, without compromising the network's QoS in the
absorption phase.