Gonzalo

Vazquez-Vilar

Ph.D. Electrical Engineering

#### Research

Gonzalo Vazquez-Vilar research interests lie in the fields of information theory, communications
theory and signal processing. Currently he is working in the field of Shannon theory with focus
on finite-length information theory and statistical hypothesis testing.

This section describes some of his contribution to the topics of cognitive radio,
main topic of his doctoral dissertation, and finite-length information theory,
his current research focus.

##### Finite-Length Information Theory

Shannon's Information Theory establishes the fundamental limits of information
processing systems. A concept that is hidden in the mathematical proofs of
most of the Information Theory literature, is that in order to achieve the
fundamental limits sequences of infinite duration are required. In our work
we study how the system performance is affected when considering **finite
block lengths**. The existing trade-off among block length, error probability
and gap to channel capacity is characterized by means of **novel upper and lower
bounds** under different settings. Connections to statistical hypothesis testing
are established.

##### Interference Management and Multiantenna Detection

First, using game theoretical tools, we propose a framework for **interference management** in which certain interaction is allowed
between primary and secondary systems under dynamic spectrum access. Secondly, we address the problem of primary user monitoring using **novel detection schemes**
exploiting multiple antennas, wideband processing, and available knowledge on the primary user transmissions. Using the generalized
likelihood ratio test (GLRT) for different signal models we study the asymptotic optimality of these and several detectors in the literature.