Research interests

I head the Wireless Solutions (WiSo) research lab at ITU, Lahore, Pakistan. The current areas of research focus include (but are not limited to) the following:

distributed/multi-user/massive MIMO:

In this problem, multiple wireless transmitters cooperate to maximize the received signal strength at some (intended) receiver (the

so-called beamforming), and minimize the received signal strength at some other (protected) receiver (the so-called nullforming). The

distributed MIMO is distributed version of antenna arrays. It will find its application in future cellular, WiFi, and emergency response

systems. We do both theoretical and experimental research (via software-defined/programmable radios) in this area.

physical layer security:

Wireless medium is a broadcast medium, and hence prone to various kinds of attacks by adversaries (e.g., jamming, impersonation, denial of service, eavesdropping). This research area focuses on securing the communication networks via means such as authentication, secret key (aka the passwords) generation and distribution etc. We do both theoretical and experimental research via software-defined radios (SDRs) in this area.

resource allocation for 5G/beyond 5G:

We investigate the resource allocation problems (distribution of cellular resources such as time, frequency, transmit antennas etc. to the users in an optimal/near-optimal way) on both uplink and downlink of cellular systems for different candidate architectures (e.g., cloud radio access network etc.). We do theoretical research in this area, but experimental research via SDRs is also possible.

wireless power transfer (WPT):

As the name implies, wireless power transfer, by definition, is to devise ways to recharge the

devices and batteries in a wireless manner. This is typically done using the techniques such as magnetic induction, microwave etc. But the actual design and implementation of energy harvesting devices is considered by people with background in circuits, materials etc. We do the mathematical modelling of the phenomena of WPT, and then do performance analysis of wireless networks under the scenario when the individual devices recharge their batteries by harvesting the received RF signals.

nano-scale communication (molecular, terahertz band):

Recently, there has been a surge of interest in body area networks, i.e., wireless sensor

networks where the individual (tiny) sensors are either deployed on the skin of the patient, or, inside body; the sensors then monitor

various parameters of the body (glucose, sugar level etc.) and report it to a data acquisition node in the nearby vicinity of the patient.

This data is then transmitted to the nearby hospital so that the doctors can monitor their patients remotely. Due to miniature size of

sensors for body-centric communication, a wireless solution is not very feasible. Therefore, recently, researchers have came up with a

new paradigm for communication between miniature sensor nodes -- the nano nodes communicate with each other via exchanging molecules. This bio-inspired concept of molecular communication mimics the interactions between the cells inside the living beings. Once again, we don't design such nano sensors. We rather mathematically model the phenomena of molecular communication and then do performance analysis of the system.

economic dispatch and security in smart grid:

Smart grid is big system which builds upon the techniques from power systems, controls, signal processing, and communications. We are interested in the problem of optimal economic dispatch in smart grid where the load demand from the users as well as the generation capacity fluctuates. Since the power generation from each generator (oil, gas, renewable energy source) comes at a cost, the goal is to minimize the generation cost while reducing the power imbalance (load-generated power) to zero in an exponentially fast manner. Additionally, we are interested to investigate the issues of security, privacy and user's anonymity at various points in the smart grid (e.g., protecting smart meters, power generation, distribution, transmission units from malicious attacks by adversaries).

Machine-to-machine communication/internet of things:

We use the tools from network calculus to analyze the network-level performance of delay-limited M2M applications.

Analytical tools we use:

Above research problems are solved by borrowing various analytical tools from signal processing, communication, probability and random variables, statistical inference, machine learning, convex optimization, information theory, channel coding etc.

Experimental tools we use:

We have GNU Radio/USRP based software-defined/programmable radios in our lab. The radios are traditionally programmed in C++ and Python; however, for advanced concepts, the need arises to program the on-board FPGA of each radio involved in the experiment.

International Collaborations:

We have collaborators at The University of Iowa, USA, KTH (Royal Institute of Technology), Stockholm, Sweden, The University of Glasgow, UK, and King Fahad University of Petroleum and Minerals, KSA.

Research talks:

GNU-radio/USRP-based software-defined radio testbed for distributed beamforming, GRCon 2012, Atlanta, USA (September 24, 2012). Video Slides

Software-defined radio: A technology development platform, Department of Electrical & Computer engineering, University of Iowa, USA (March 1, 2011).