Assoc. Prof. Dr. Ahmad Zuri bin Sha’ameri obtained his B. Sc. in Electrical Engineering from the University of Missouri-Columbia, USA in 1984, and M. Eng. Electrical Engineering and Ph D both from UTM in 1991 and 2000 respectively. At present, he is a member of the Digital Signal and Image Processing (DSIP) Research Group and Academic Coordinator for the DSP Lab, Electronic and Computer Engineering Department, Faculty of Electrical Engineering, UTM. His research interest includes signal theory, signal processing for radar and communication, signal analysis and classification, and information security. The subjects taught at both undergraduate and postgraduate levels include digital signal processing, advance digital signal processing, advance digital communications and information security. He has also conducted short courses for both government and private sectors. At present, he has published 160 papers in his areas of interest at both national and international levels in conferences and journals.
Besides applications in civil aviation, maritime, defence and homeland security, wireless positioning system has found its use in other variety of applications and services such as enhanced-911, improved fraud detection, location based services, location sensitive billing, intelligent transport systems and improved traﬃc management. Active implementation such radar due with its relatively high transmit power is not suitable for indoor use and has a potential for causing interference or health hazards to potential users. Passive implementation such as global navigation surveillance system (GNSS) has some limitations such as high power consumption, blocking of the RF signal by foliage and buildings. Since the tracked objects usually emit electromagnetic signals, it is possible to perform passive wireless positioning by intercepting and performing analysis on these signals to perform identification based on the signal parameters or information content. By employing multiple receivers, the spatial difference between the intercepted signals can be exploited by estimating the difference between the received signal strength indication (RSSI), angle of arrival (AOA) and time delay of arrival (TDOA) to determine the position of the tracked object. To complete the process, an efficient backbone network should be in place to enable efficient and error free data link between all the receiving stations and a centralized processing system. Current IP based infrastructure and internet of things (IOT) concept can used to form the backbone network for a wireless positioning system.
Despite its benefits, performing a passive wireless positioning system has its own share of challenges. In a noncooperative environment where prior knowledge on the parameters of the possible signals within the band is unknown, among the challenges are noise in the intercepted signal with multipath fading and signals with a combination of the following characteristics: large bandwidth, short duration, and low peak power. Thus, the objective of this presentation is to highlight the possible signal reception technologies through channelized receiver configuration and high speed scanning, signal detection and enhancement with de-noising techniques and the use of time-frequency analysis to estimate the signal parameters for identification. Once identified, the next step is to estimate the position of the tracked object by first estimating the position related parameters such as RSS, AOA or TDOA which is then used by the position estimation process. Field trials results will be presented from the interception of signals at the campus of Universiti Teknologi Malaysia, Johor Bahru and Gunung Raya, Langkawi for automatic dependent surveillance broadcast (ADS-B) signals from aircrafts, short range locating by RSSI fingerprinting and drone locating by TDOA. The results will demonstrate use of wireless positioning for use with different applications.