His research interests are in adaptive signal processing for communications, wireless communications, modelling and identification of nonlinear systems, learning theory and neural networks, finite-precision digital controller design and networked control systems, evolutionary computation methods and optimisation.

In the original database of the world's most highly cited researchers in various disciplines, compiled by Institute for Scientific Information (ISI) of the USA, Professor Chen is on the list of the highly cited researchers in the engineering category (March 2004).