Inside view

Abstract

Researchers from the Sun Yat-sen University in China have presented a new transmission scheme for the Internet of Vehicles to recover information from simultaneously broadcast signals that are overlapped. We spoke to Professor Xiao Ma, one of the authors, to find out more about his and his team's latest work. My research interests include channel coding, information theory, and their applications. While our mobile devices are becoming smaller but providing more functions, people require more reliable transmission to guarantee real-time demands. On the other hand, more and more smart devices will access the Internet. It becomes a challenge to build a network framework to utilise the network resource fully. I was very interested in developing superposition coding and transmission which provides an efficient way to utilise channel resource and gain more performance. Professor Xiao Ma from Sun Yat-sen University in China The proposed decoding algorithm SCL-based IEDA (red) performs well compared to other popular algorithms Internet of Vehicles (IoV) can be seen as a special Internet of Things (IoT). Using information interaction among vehicles, humans and the roadside unite. IoV helps people to collect real-time traffic information and gain more convenience and comfort. Since more and more cars and other vehicles are used daily by people, a large number of devices require access to the IoVs. Different from traditional IoT communication, IoV is deployed to transmit rapidly and reliably the road condition information (e.g. traffic jam notifications) in most cases. With IoV communication, we can build autonomous vehicles and improve travel safety and convenience. In the non-orthogonal overlapping transmission system in this Letter, we use power allocation to distinguish two signals from different relay nodes. In the destination node, we present a successive cancellation list based interference elimination decoding algorithm (SCL-based IEDA) for information recovery. Instead of outputting a single pair of estimated information sequences using a traditional SCL decoder, our decoding algorithm outputs more alternative pairs of estimated information sequences and picks up the most probable one. The significance of our work is that we can recover information from the overlapped signals by the presented decoding algorithms, even if the signals are highly overlapped in the same time slot and frequency band. By power allocation, we distinguish the signals so that the information in the highly overlapped signals is recoverable. Our scheme can not only be applied to the mentioned application scenario in this paper, but also be extended to other many-to-one communication networks to improve the throughput of the network. The long term impacts of this work mainly include: 1) With polar code being selected for the 5G standard, this work will attract more people to pay attention to polar code and its application in multi-user transmission systems. 2) The Internet of Vehicles is regarded as one of the typical 5G application scenarios of URLLC, which requires a transmission with high reliability and low latency. The polar code-based overlapping transmission scheme may find applications in improving the transmission efficiency in IoVs. Our further plans for developing this work include：1) Try to improve the decoding algorithm of the proposed overlapping transmission. 2) Consider the case when more than two signals from different relay nodes are overlapped and study the corresponding decoding algorithms for information recovery. 3) Conduct simulations under a more complex and practical wireless channel model to further investigate the information recovery performance of the proposed decoding algorithm. Currently, we are actively working on the above mentioned plans. As we all know, dedicated short range communications were used for vehicle communications in the US. On the other hand, EN 202 663 was used in Europe. However, due to the limited range and low speed transmission, research attempts have been made on cellular based Vehicle to Everything (C-V2X) communications. The benefits of C-V2X communication, compared to prior technologies, are that it can accommodate more users, provide faster transmission speed, and is of lower latency performance. As part of the evolution of cellular communications, the forthcoming fifth generation, V2X (5G-V2X), communications will further leverage this trend. In the coming ten years, it is believed that along with new energy resources, automatic driving, accurate image detection, and three-dimensional scene reconstruction technologies, C-V2X will further leverage the driving experience and rebuild the car industry. Although C-V2X has been widely discussed in literature, there is still a lot of work that needs to be done before its application, for instance, frequency bandwidth allocation and its effective usage, precise vehicle transmission channel measurement and modelling, seamless wireless connection for massive connected devices (vehicles, pedestrians, etc.), URLLC, even fast speed transmissions for in-car entertainment, vehicle network security and flexible network architecture for fast moving vehicles.