Optimizing Spectral-Efficient Communication and Computation for Distributed Reconfigurable Intelligent Surfaces Assisted Probabilistic Semantic Communication in Industrial Internet-of-Things

Core Concepts

The authors propose a joint communication and computation framework to maximize the sum semantic-aware transmission rate in a distributed reconfigurable intelligent surfaces (RISs) assisted probabilistic semantic communication (PSC) system for industrial Internet-of-Things (IIoT).

Abstract

The paper investigates the problem of spectral-efficient communication and computation resource allocation for distributed RISs assisted PSC in IIoT. In the considered model, multiple RISs are deployed to serve multiple users, while PSC adopts the compute-then-transmit protocol to reduce the transmission data size.
To support high-rate transmission, the semantic compression ratio, transmit power allocation, and distributed RISs deployment must be jointly considered. The authors formulate this joint communication and computation problem as an optimization problem to maximize the sum semantic-aware transmission rate under total transmit power, phase shift, RIS-user association, and semantic compression ratio constraints.
To solve this problem, the authors propose a many-to-many matching scheme to solve the RIS-user association subproblem. The semantic compression ratio subproblem is addressed following a greedy policy, while the phase shift of the RIS can be optimized using tensor-based beamforming. Numerical results verify the superiority of the proposed algorithm compared to conventional schemes.

Stats

The total transmit power of the base station is denoted by P.
The maximum computation budget of the base station is denoted by Q.
The minimum semantic compression ratio of user k is denoted by ρmin_k.

Quotes

"Reconfigurable intelligent surfaces (RISs) exhibit great potential in providing feasible and energy-efficient solutions to massive data traffic and high reliability of wireless communications at low cost."
"Semantic communication has recently garnered significant attention in the field of wireless communications. This emerging paradigm involves joint source and channel coding, wireless resource allocation, learning resource allocation, etc."

Key Insights Distilled From

A Joint Communication and Computation Design for Distributed RISs Assisted Probabilistic Semantic Communication in IIoT

by Zhouxiang Zh... at arxiv.org 05-01-2024

https://arxiv.org/pdf/2404.19750.pdf

Deeper Inquiries

How can the proposed joint communication and computation framework be extended to support more advanced semantic communication techniques, such as multi-modal semantic information extraction and transmission

The proposed joint communication and computation framework can be extended to support more advanced semantic communication techniques, such as multi-modal semantic information extraction and transmission, by incorporating additional computational resources and algorithms.
To support multi-modal semantic information extraction, the framework can be enhanced with machine learning models capable of processing and extracting information from various data types, such as images, text, and audio. This would involve integrating deep learning algorithms, natural language processing techniques, and computer vision models into the system to enable the extraction of semantic information from different modalities.
Furthermore, the framework can be expanded to include multi-modal data fusion techniques, where information from different modalities is combined to provide a more comprehensive understanding of the data. This would involve developing algorithms that can effectively fuse information from diverse sources and modalities to enhance the semantic communication process.
Additionally, the framework can be extended to support multi-modal transmission, where the extracted semantic information from different modalities is transmitted efficiently to the intended recipients. This would involve optimizing the transmission process to accommodate the diverse nature of the data and ensure reliable and efficient communication across different modalities.
By incorporating these advanced techniques into the framework, it can be tailored to handle complex semantic communication scenarios involving multi-modal data, enabling more sophisticated and efficient communication in industrial IoT applications.

What are the potential drawbacks or limitations of the greedy policy used to optimize the semantic compression ratio, and how could alternative optimization approaches be explored

The greedy policy used to optimize the semantic compression ratio may have limitations in terms of achieving the global optimal solution and may get stuck in local optima. To address these drawbacks, alternative optimization approaches can be explored to enhance the efficiency and effectiveness of the semantic compression ratio optimization process.
One alternative approach is to employ metaheuristic optimization algorithms, such as genetic algorithms, particle swarm optimization, or simulated annealing, to search for the optimal semantic compression ratio. These algorithms can explore a larger solution space and have the potential to find better solutions compared to the greedy policy.
Another approach is to formulate the semantic compression ratio optimization as a convex optimization problem and utilize convex optimization techniques to find the optimal solution. By transforming the problem into a convex form, it becomes easier to solve and guarantees convergence to the global optimum.
Furthermore, reinforcement learning techniques can be employed to optimize the semantic compression ratio iteratively. By training a reinforcement learning agent to make decisions on adjusting the compression ratio based on feedback from the system's performance, the optimization process can be automated and improved over time.
By exploring these alternative optimization approaches, the limitations of the greedy policy can be mitigated, and the semantic compression ratio optimization process can be enhanced to achieve better performance and efficiency in the joint communication and computation framework.

Given the importance of energy efficiency in IIoT applications, how could the proposed framework be further enhanced to jointly optimize energy consumption and spectral efficiency

To further enhance the proposed framework to jointly optimize energy consumption and spectral efficiency in IIoT applications, several strategies can be implemented:

Dynamic Power Allocation: Implement dynamic power allocation algorithms that adjust the transmit power levels based on the channel conditions and traffic requirements. By dynamically allocating power, the system can optimize energy consumption while maintaining spectral efficiency.

Energy-Efficient Beamforming: Develop energy-efficient beamforming techniques that focus on directing signals towards the intended recipients with minimal power consumption. By optimizing the beamforming patterns, the system can reduce energy wastage and improve spectral efficiency.

Sleep Mode Mechanisms: Introduce sleep mode mechanisms for RIS elements and user devices to conserve energy when not actively transmitting or receiving data. By intelligently managing the sleep modes, the system can reduce overall energy consumption without compromising performance.

Energy Harvesting Integration: Integrate energy harvesting technologies, such as solar panels or kinetic energy harvesters, to power the RISs and user devices. By leveraging renewable energy sources, the system can reduce reliance on traditional power sources and improve energy efficiency.

Cross-Layer Optimization: Implement cross-layer optimization techniques that consider energy consumption and spectral efficiency across different layers of the communication system. By jointly optimizing parameters at the physical, MAC, and network layers, the system can achieve a balance between energy efficiency and spectral efficiency.

By incorporating these strategies into the framework, the system can achieve a holistic approach to optimizing energy consumption and spectral efficiency in IIoT applications, leading to improved performance and sustainability.