My research interests are broadly in the areas of performance analysis of mobile broadband wireless networks and in building next-generation shared air interface.
Particular research topics include:
- Intercell Interference Coordination Schemes
- Non-Orthogonal Spectrum Sharing
- HetNets
- Hypergeometric functions
- Generalized fading models.
Non-Orthogonal Spectrum Sharing
The three key technologies  to provide high rates are expected to be high-bandwidth millimetre wave links,  massive MIMO systems and dense small-cells. On the other hand, to provide cost-effective coverage in large rural or semi-urban areas where the user density is low, service providers would prefer the usage of the sub 1GHz frequency bands for the link budget advantage, and large macro cells with sectored antennas to ensure a good compromise between bit-rate, coverage, and network cost. However, the sub 1GHz frequency bands are at a premium, and it is a challenge to utilize these bands effectively to provide highly spectrally efficient broadband communications. While the 700MHz band is seen by many researchers to be effective for narrow-band IoT applications, in many parts of the world where basic internet access has to be wirelessly provided, it is likely that this band as well as the TV-UHF band (470MHz to 698MHz) will be utilised first to provide high-speed data services to domestic users situated in towns and villages. Indeed, migration or re-farming of terrestrial TV transmission bands has been initiated in many countries in order to accommodate such mobile broadband access technologies in the TV-UHF band.  We believe non-orthogonal spectrum sharing between multiple licensed operators can reduce the cost of ownership of premium bands below 1GHz, and especially so in the TV-UHF band where re-farming of spectrum is possible.
Generalized fading models
The well known fading distributions have been derived assuming a homogeneous diffuse scattering field. However, this assumption is certainly an approximation, because the surfaces are spatially correlated, which characterizing a non-homogeneous environment. For non-homogeneous environment, two generalized fading, namely, κ-µ fading and η-µ fading were proposed in for modeling line-of-sight and non-line-of-sight propagation effects, respectively.