The propagation channel is the principal contributor to many of the problems and limitations that degrades the performance of mobile radio systems. One obvious example is multipath propagation which is a major characteristic of the mobile radio channels, which severely affects the performance of digital systems by reducing the carrier-to-interference ratio. Thus accurate characterization of the...

The concept of non-orthogonal multiple access (NOMA) is presented as a candidate radio access technology for systems beyond the 4th generation (4G) mobile communication systems. NOMA, which is different from the current long term evolution (LTE) radio access schemes, utilizes the power domain for user multiplexing at the transmitter side and adopts a successive interference cancellation (SIC) r...

To support the continuously increasing number of mobile telephone users around the world, mobile communication systems have become more advanced and sophisticated in their designs. As a result of the great success with the second generation mobile radio networks, deployment of the third and development of fourth generations, the demand for higher data rates to support available services, such a...

In comparison to existing 3G or 3G+ wireless systems, fourth generation (4G), long-term evolution (LTE) or mobile Wimax are characterized by higher bit rates, highly fluctuant traffic matrices and higher antenna’s density. Current backhauling techniques federating radio antennas are not suited to these new characteristics. Several investigations are carried out for the design of new generation ...

Engmcenng, Nnlronol Unrversuy o f Slngupore. ublic cellular radio systems are less than two decades old. The concepts of cellular radio are much older, rooted in the O OS, when technology was far too immature to support such complex systcms. There are two main components in mobile radio systems.Theradiointerface,whichallowsuserstowander while communicating via radio from a mobile station (MS) t...

Authentication and privacy refer to the problems of ensuring that communication takes place only between the right parties without disclosure of information to unauthorized eavesdroppers. Radio communication is highly appealing for the convenience of mobility—the freedom from a fixed location. For this reason, wireless services have been growing rapidly. In 2005, an ITU study found more than 2 ...

In this paper a new approximate method for the computation of outage probabilities in a mobile radio environment is proposed. It allows one to evaluate the performance of a mobile radio system in the presence of fading, in a very fast and accurate way, while maintaining a very good flexibility as to the application to different network environments. Coding is also considered as a possible choic...

In this paper, we examine the performance enhancements that can be achieved by employing adaptive antennas in Code Division Multiple Access (CDMA) cellular radio systems. The goal is to determine what improvements are possible using narrowbeam antenna techniques, assuming that adaptive algo. rithms and the associated hardware to implement these systems can be realized. Simulations and analytica...

A general analytical framework quantifying the spectral eeciency of cellular systems with variable-rate transmission is introduced. This eeciency, the area spectral eeciency, deenes the sum of the maximum average data rates per unit bandwidth per unit area supported by a cell's base station. Expressions for this eeciency as a function of the reuse distance for the worst-case and best-case inter...

A general analytical framework quantifying the spectral efficiency of cellular systems with variable-rate transmission is introduced. This efficiency, the area spectral efficiency, defines the sum of the maximum average data rates per unit bandwidth per unit area supported by a cell’s base station. Expressions for this efficiency as a function of the reuse distance for the worst and best case i...