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Resource optimization becomes mandatory in radio spectrum because of limited resources. The effective utilization of resources is the need of wireless era. Cognitive radio is a technology which enables opportunistic access to radio spectrum and has ability to analyze and learn about the environment conditions. Most of the radio spectrum is underutilized. Cognitive radio has the ability to sense the...
The development of mobile communication services has lead to the increase the use of wireless spectrum. However, the persuasion of the overly crowded spectrum is not due to the scarcity of usable radio frequencies but to the current static spectrum management policy. This reveals many idle frequency bands in both time and space. The cognitive radio network (CRN) is a key solution to exploit the existing...
Dynamic spectrum access research usually considers very short time-scale secondary access based on spectrum sensing local to the radio. Recent discussion of market mechanisms in civil spectrum management consider longer time-scales of hours and days, still much faster than current processes. We conjecture that many of the benefits of dynamic spectrum management can be realized on a time-scale of minutes...
Future wireless services are expected to provide data-rates in the order of 1 Gbps in local area and 100 Mbps in wide area. A very wide bandwidth is required to support such high rates, in the order of 100 MHz: this wideband will not be available for each operator, thus a shared access to the spectrum among operators is needed. An holistic approach to spectrum sharing is adopted in this paper: not...
In this paper, we propose a cognitive radio-based multi-user resource allocation framework for mobile ad hoc networks using multi-carrier DS CDMA modulation over a frequency-selective fading channel. In particular, given pre-existing communications in the spectrum where the system is operating, in addition to potential narrow-band interference, a channel sensing and estimation mechanism is provided...
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