Research Areas
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Broadband Wireless Access Networks Resource Allocation
Broadband wireless access (BWA) networks are being developed to replace the last mile wireline access networks such as DSL and cable networks. The simple and small receiver structure allows BWA networks to provide service directly to subscribers, without the need for intermediate receivers (i.e., modems), which is the case for wireline networks. In addition, BWA networks are suitable for providing service in countries that lack fiber optics infrastructure, or have low population density or with rough topographies where laying cables is expensive. Because of their fast deployment in comparison to wired networks, they can be used in disaster recovery. Figure below illustrates an example of BWA networks. Standards that specify the technical aspects of BWA networks are IEEE 802.16, the high performance radio metropolitan area network (HiperMAN), the European telecommunication standard, and the 3rd generation partnership project (3GPP).
Due to the limited availability of resources at the base station, e.g., bandwidth and power, intelligent allocation of these resources to subscribers is crucial for delivering the best possible quality of service (QoS) to consumers with the least cost. This is especially important with the high data rates envisioned for the next generation wireless standards. The resource allocation problem of allocating time slots, subcarriers, rates, and power to subscribers has been the focus of my research work.
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Source Tracking & Acoustic Signal Processing
Hydrophones are piezoelectric transducer based microphones that detects sounds underwater. The piezoelectric transducer generates an electric signal when the acoustic pressure changes.
A velocity-hydrophone measures one Cartesian component of the three dimensional particle-velocity vector of the incident wavefield. Velocity-hydrophone technology has existed for decades in the field of underwater acoustics and is the subject of renewed interest. A four-component vector-hydrophone has two or three orthogonally oriented velocity-hydrophones and a pressure hydrophone, all collocated in a point-like geometry. A four-element vector-hydrophone (located at the coordinates' origin as illustrated in Figure 1) simultaneously estimates both the azimuth and the elevation arrival angles of the acoustic signal. Hence, it tracks the source generating it under water.
Our work focuses on the design of tracking algorithms that track the source in various settings based on Hydrophones' measurements.