Organizations: School of Internet of Things Engineering, Jiangnan University, Wuxi 214122, China · State Key Laboratory of Space Network and Communications, Beijing National Research Center for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China · Qualcomm, San Jose, CA 95110, USA
To support latency-sensitive Internet of Vehicles (IoV) applications amidst dynamic environments and intermittent links, this paper proposes a Reconfigurable Intelligent Surface (RIS)-aided semantic-aware Vehicle Edge Computing (VEC) framework. This approach integrates RIS to optimize wireless connectivity and semantic communication to minimize latency by transmitting semantic features. We formulate a comprehensive joint optimization problem by optimizing offloading ratios, the number of semantic symbols, and RIS phase shifts. Considering the problem's high dimensionality and non-convexity, we propose a two-tier hybrid scheme that employs Proximal Policy Optimization (PPO) for discrete decision-making and Linear Programming (LP) for offloading optimization. {The simulation results have validated the proposed framework's superiority over existing methods. Specifically, the proposed PPO-based hybrid optimization scheme reduces the average end-to-end latency by approximately 40% to 50% compared to Genetic Algorithm (GA) and Quantum-behaved Particle Swarm Optimization (QPSO). Moreover, the system demonstrates strong scalability by maintaining low latency even in congested scenarios with up to 30 vehicles.
Figures & tables
Figure 1: Framework of semantic communication system.
Figure 2: System model diagram.
Parameters
Value
Parameters
Value
ηr,j
2.2
pk,j
0.2 W
N
6×6
σ2
1.44×10−10 W
K
15
ηk,j
3.5
ηk,r
2.2
W
360 kHz
C
1000 cycles/bit
Ik
100
fkloc
2 GHz
FRSU
6 GHz
Table 1: Simulation environment parameter table.
Figure 3: Reward convergence plot of PPO.
Figure 4: Performance comparison of average delay under varying vehicle transmission powers.
Figure 5: Average delay of V2V and V2I links versus vehicle transmission power.
Figure 6: Boxplot of average delay under different numbers of vehicles.
Figure 7: Average delay versus number of vehicles.
Figure 8: Average delay versus number of RIS-reflecting elements.
Figure 9: Boxplot of total delay under different numbers of RIS-reflecting elements.