The authors consider underwater acoustic (UWA) channel estimation based on sparse recovery using the recently developed homotopy algorithm. The UWA communication system under consideration employs orthogonal frequencydivision multiplexing (OFDM) and receiver preprocessing to compensate for the Doppler effect before channel estimation. The authors first extend the original homotopy algorithm whi...

Modern mobile telecommunication systems are using MIMO combined with OFDM, which is known as MIMO-OFDM systems, to provide robustness and higher spectrum efficiency. The major challenge in this scenario is to obtain an accurate channel estimation to detect information symbols, once the receiver must have the channel state information to equalize and process the received signal. Channel estimati...

the sender and the clients. However, the reliability and efficiency of end-to-end FEC-based packet video could suffer significantly over large video distribution networks. In this paper, we explore a new alternative for improving the reliability and efficiency (in terms of throughput) of packet video applications by optimum placement of few FEC codecs within large packet video distribution netw...

This chapter presents a study on the interference caused by Secondary Users (SUs) due to miss-detection errors and its effects on the capacity-outage performance of the Primary User (PU) in a cognitive radio network assuming Rayleigh and Nakagami fading channels. The effect of beacon transmitter placement on aggregate interference distribution and capacity-outage performance is studied consider...

This paper studies cache-aided interference networks with arbitrary number of transmitters and receivers, whereby each transmitter has a cache memory of finite size. Each transmitter fills its cache memory from a content library of files in the placement phase. In the subsequent delivery phase, each receiver requests one of the library files, and the transmitters are responsible for delivering ...

Channel capacity of multi-element communication systems in independent Rayleigh channels has been shown to scale linearly with the number of antennas. In reality, the signals received by different receiver antennas can be correlated with each other due to the non-uniform scattering environment and limited aperture of the antenna system. In this paper, the effect of spatial correlation between r...

We consider a problem of robotic router placement and mobility control with the objective of formation and maintenance of an optimal communication network between a set of transmitter-receiver pairs. In this scenario, the communication path between any transmitter-receiver pair contains a predetermined set of mobile robotic routers nodes. The goal of this work is to design an algorithm to optim...

A theoretically derived antenna saturation point is shown to exist for MIMO systems, at which the system suffers a capacity growth decrease from linear to logarithmic with increasing antenna numbers. We show this saturation point increases linearly with the radius of the region containing the receiver antennas and is independent of the number of antennas. Using an alternative formulation of cap...

Wireless Sensor Networks (WSNs) are communication networks, which integrate sensor techniques, embedded techniques and distributed information processing techniques. One of the issues in smart sensor networks is achieving energy efficient operation because of the limited available power. In many biomedical applications, the locations of sensor nodes are fixed and the placement can be predetermi...