This paper addresses the problem of accurately modeling the spectrum occupancy patterns
of real radio communication systems, which is an essential aspect in the study of cognitive …

In this paper, we study a hybrid interweave-underlay spectrum access system that integrates
amplify-and-forward relaying. In hybrid spectrum access, the secondary users flexibly switch …

The spectrum occupancy models widely used to date in dynamic spectrum access/cognitive
radio (DSA/CR) research frequently rely on assumptions and oversimplifications that have …

Extensively increasing numbers of radio electronic devices significantly complicate the
electromagnetic situation under conditions of radio frequency spectrum deficiency and …

This paper presents an empirical time-dimension model of spectrum use in the context of
dynamic spectrum access. Concretely, a discrete-time two-state Markov chain with novel …

Lack of frequency spectrum is becoming one of the major problems in the
telecommunication field with the introduction of several new radio communication …

Cognitive Radio (CR) is aimed at increasing the efficiency of spectrum utilization by allowing
unlicensed users to access, in an opportunistic and non-interfering manner, some licensed …

The dynamic spectrum access (DSA) principle, relying on the cognitive radio (CR) paradigm,
allows users to access spectrum over time intervals or spatial areas where it remains …

The increased number of wireless communication systems in the last decades raised the
problem of the limited resources in the frequency domain. Cognitive Radio (CR) technology …

A suitable spectrum policy is essential to allow efficient use of the radio spectrum. The
Japanese government currently employs a Command and Control (C&C) regime, but …