Recently, Tarokh and others have raised the possibility that a cognitive radio might know the interference signal being transmitted by a strong primary user in a non-causal way, and use this knowledge to increase its data rates. However, there is a subtle difference between knowing the signal transmitted by the primary and the actual interference at our receiver since there is a wireless channe...

A simply described achievable rate region is obtained for the genie-aided cognitive radio channel using the Han-Kobayashi celebrated jointly decoding strategy for the interference channel and the Gel’fandPinsker coding scheme for channels with side information known at the transmitter, and then is simplified by Fourier-Motzkin elimination. The obtained achievable rate region (i) extends the Cho...

Cognitive radio is expected to have the capability to sense the changes of the environment and adapt its communications parameters accordingly. Ideally, adaptation shall be done autonomously and collaboratively. In [1], we proposed an ontology and policy based approach to enable autonomous and collaborative adaptation of cognitive radio parameters. In this approach, an ontology is developed to ...

Cognitive Radio is an emerging wireless technology that has grabbed the attention of researchers, academicians, and telecommunication industries worldwide. Recent survey reports show that unlicensed frequency bands have become overcrowded from past few years with widespread acceptance of diverse wireless technology applications whereas, licensed frequency bands are being used intermittently. To...

The main objective of this paper is to demonstrate the feasibility of the ontology and policy based approach to realize collaborative, automatic adaptation of cognitive radio parameters in the transmitter and receiver. The ontology and policy based approach features the following three aspects. First, all the internal and external information of the radio is represented in the Web Ontology Lang...

In this outdoor propagation study, low antenna heights of 1. 7 m are used at both the transmitter and the receiver to measure wideband (100 MHz baseband) power-delay profiles (PDPs) of the channel for a peer-to-peer communications system operating at 1.8 GHz. Rural and urban areas are studied in 22 different transmitter-receiver links, and the path loss and delay spread characteristics are pres...

Complies with the regulations of the University and meets the accepted standards with respect to originality and quality. Date_____________________________________ iii ABSTRACT Millimeter wave radio over fiber (RoF) system has emerged with competitive advantages of high bandwidth and low distribution cost to meet the increasing demanding for high data rate wireless access. In RoF system, optica...