Typically, a device in an ad hoc wireless network has a tunable radio allowing it to listen or transmit on one channel at a time. To ensure maximum connectivity, all devices tune their radio to the same channel. However, as node density increases, the interference worsens, resulting in lower throughput per device. Some of the interference is unnecessary. Modern radios can often switch channels ...

Energy consumption and throughput optimization in cognitive radio networks (CRNs) are two critical issues that have attracted more attention recent years. In this paper, we consider maximization of the energy efficiency improvement as metrics for jointly optimizing sensing times detection thresholds each sub-channel selecting spectrum (SS) data transmitting multi-antenna secondary users (SUs) m...

A radio-interface concept for a ubiquitous WINNER radio system is presented and assessed, both in terms of performance and in terms of implementation complexity. The developed radio-interface concept is a packet-oriented, user-centric, always-best concept targeting 100 Mbps sector-throughput for wide-area coverage and 1 Gbps for local-area coverage. It defines a scalable and flexible radio inte...

Spectrum sensing is studied for multi-user cognitive radio networks in this paper. An improved spectrum sensing method----energy-cooperative detection method is developed, which combines the double threshold energy detecting method with the “OR” fusion decision rule. The simulation is done for both AWGN channel and Rayleigh channel, and the advantages of the improved method are verified.

A confidential and effective probing is fundamental to a cooperative and cognitive wireless network. Previous seminar works are not deadline sensitive, and often suffer from highly dynamic multi-channel environments. As they focus more on transmitting packets with the optimal channel, resources are not efficiently used when sufficient channels are available in multi-radio multi-channel systems....

Over the past decades there has been technological breakthrough from analog to digital. Ever since the world war and also the invention of electromagnetic radio, there has always been an urge to know from which direction the signals were arriving to the listener’s direction finding receiver. The methodology of determining the direction of arrival (DOA) of incoming signals impinging on the unifo...