Theory and Analysis

Monday, August 22, 2011

WNCG has multiple experts actively working on the fundamental underpinnings of networks and communication systems. In WNCG, researchers from different theoretical disciplines come together in a collaborative environment to address challenges posed by next generation wireless systems. The group's aim is to use theory to inspire practice; translating theoretical innovation into system design, development and deployment by partnering with our affiliates.

Network Capacity Limits/ Multi-terminal Information Theory

Various aspects and definitions of network capacity are currently under investigatation, including traditional Shannon capacity regions, ergodic, outage, transport and worst-case capacities. Additionally, tools from large deviation theory, matrix theory, stochastic geometry and statistical mechanics are being used to study the capacity of sensor and ad hoc networks. (Andrews, Arapostathis, Caramanis, de Veciana, Heath, Qiu, Shakkottai, Vishwanath)

Multi-user MIMO Theory

A diverse set of MIMO strategies are under investigation. These include limited feedback techniques for MIMO (using Grassmanians), space-time code design, diversity-multiplexing tradeoffs and performance evaluation of MIMO systems under diverse constraints and settings. (Andrews, Evans, Heath, Shakkottai, Vishwanath)

Network Asymptotics

The study of scaling laws that govern network behavior is being performed on multiple fronts which include network throughput, average worst-case delay and robustness. Tools from applied probability such as queuing theory, large deviations fluid limits are used in this context to analyze networks. (Arapostathis, Caramanis, de Veciana, Shakkottai)

Network Scheduling and Utility Maximization

Resource allocation, scheduled and random access schemes are currently under investigation given user utilities under a variety of constraints imposed on the system. These include, but are not limited to, channel-aware access schemes, scheduling in heterogeneous networks, analysis and design of asymptotically optimal schedulers and schedulers for multiple-antenna systems. (Caramanis, de Veciana, Heath, Qiu, Shakkottai)

Joint Source-Channel Coding

WNCG researchers are working on designs of joint compression and error correction schemes that best exploit the structure of the source with minimal increase in complexity. Both image and video sources are being considered, with the goal of ensuring that the ultimate quality of the source after encoding given system constraints is maximized. (Bovik, Heath, Vishwanath)

Communication Theory (modulation performance analysis)

Various communication schemes including CDMA, OFDM/A and other multicarrier schemes are under investigation by the group for wire-line, cellular and ad hoc networks. WNCG expertise in this area is both wide and deep, with researchers contributing their innovative ideas to IEEE standardization bodies. (Andrews, Evans, Heath, Rappaport)

Control Optimization Theory for Communication/Networks

There are two aspects on this front: a) Joint design of communication and control systems and b) Use of system and optimization-theoretic tools to analyze and design networks. (Arapostathis, Caramanis, Shakkottai) Both the design of network codes for reliable and high-throughput delivery over networks and the implications of the use of network coding for congestion control and resource allocation are being investigated by members of the group. Scenarios being studied include wireline, ad hoc and delay tolerant networks. (Qiu, Shakkottai, Vishwanath)

Signal Processing on Manifolds

Manifolds are generalizations of surfaces to higher dimensions and can be used to capture structure in signals. New signal processing tools are being developed to average, predict, interpolate, filter, and quantize manifold-valued signals. The focus of current research is on the Stiefel and Grassmann manifolds, which are pervasive in applications that involve bases and subspaces like multi-antenna wireless communication and data mining. (Heath)