Adaptive WHT Aided QAM for Fading Channels Subjected to Impulsive Noise

The Bit Error Rate (BER) expressions of Walsh-Hadamard Transform (WHT) aided Quadrature Amplitude Modulation (QAM) transmitted in impulsive noise environments are derived. It is found that there is a crossover point between conventional and WHT-aided schemes’ BER curves, above which WHT is beneficial in terms of the corresponding BER performance. The exact crossover SNR is analysed and its approximate closed-form expression is derived for a QPSK scheme based on the Chernoff bound. An adaptive WHT scheme is proposed for QAM systems, where the transmitter activates the WHT only when the instantaneous SNR at the receiver is higher than the crossover SNR. The theoretical BER of our adaptive WHT scheme is derived for QAM systems operating over Nakagami-m fading channels. It is found that our adaptive WHT scheme is effective in terms of mitigating the detrimental effects of impulsive noise over the entire SNR range

Intelligent Aerial-Ground Surveillance and Epidemic Prevention with Discriminative Public and Private Services

Since complete surveillance is essential to provide safe daily life to citizen in smart cities, the issue of how to achieve secure surveillance has been driven by various research communities. Also, due to recent epidemic spread such as COVID-19, it is obvious that we should focus on how to manage a cooperative framework for possible future pandemic fights and allied medical services continuously. To support those purposes, it is anticipated that we can utilize AI-assisted communications and technologies using a variety of devices and equipment, including UAVs, mobile robots, and smart devices on the aerial and ground sides. In this article, an aerial-ground cooperative infrastructure is designed to study surveillance and epidemic prevention with managing energy recharge and AI-supported communications through collected or pre-knowledge information for public and private areas. Also, in the proposed architecture, we specify system settings, promising scenarios, and strategies in order to satisfy several objectives and tasks. Then possible research challenges and issues are addressed for successful realization and management of intelligent surveillance and efficient epidemic prevention

Link-Quality Measurement and Reporting in Wireless Sensor Networks

Wireless Sensor networks (WSNs) are created by small hardware devices that possess the necessary functionalities to measure and exchange a variety of environmental data in their deployment setting. In this paper, we discuss the experiments in deploying a testbed as a first step towards creating a fully functional heterogeneous wireless network-based underground monitoring system. The system is mainly composed of mobile and static ZigBee nodes, which are deployed on the underground mine galleries for measuring ambient temperature. In addition, we describe the measured results of link characteristics such as received signal strength, latency and throughput for different scenarios