Affiliation:
1. Department of Electronics, Telecommunications and Informatics University of Aveiro Aveiro Portugal
2. Instituto de Telecomunicações Aveiro Portugal
3. School of Technology and Management Polytechnic of Leiria Leiria Portugal
4. Optical Communications Research Group Faculty of Engineering and Environment Northumbria University Newcastle upon Tyne UK
Abstract
AbstractThe technical feasibility of developing an Internet of Things multi‐user communication system is evaluated based on a central digital multiband carrierless amplitude and phase transmitter, which broadcasts data on multiple channels for a number of low‐cost/low‐power devices. It addresses the issue of carrier synchronisation, which is critical in real‐world implementations because of imperfections of devices and the delays of the system. A simulation model for the traditional Costas Loop is presented, along with performance results, which demonstrate the system's ability to synchronise with pull‐in and lock ranges of ±800 and ±900 Hz, respectively. The loop requires 1.194 ms to be in the locked state, allowing the system to lock within 6 symbols period. In addition, the authors measured the performance of the system in the presence of noise and interference from other modulated bands. The results showed that noise and interference did not degrade the system's performance. Although the system was unable to lock when energy was present in adjacent bands, alternative options such as a high order phase‐locked loop and hybrid frequency‐division multiple access and time‐division multiple access, can improve system performance without significantly increasing the cost and complexity of the devices.
Funder
European Cooperation in Science and Technology
Publisher
Institution of Engineering and Technology (IET)
Subject
Electrical and Electronic Engineering,Atomic and Molecular Physics, and Optics