Cognitive radios are a natural evolution of Software Defined Radios (SDRs) that are supposed to be equipped with the ability to learn their RF environment and reconfigurability. A cognitive radio can communicate over a primary user’s channel as long as the introduced interference does not degrade the primary Single-to-Interference-plusNoise-Ratio (SINR) below its minimum Quality of Service (QoS...

In a previous work, we introduced a spectrum sharing technique called Multi-User Vandermonde-subspace Frequency Division Multiplexing (MU-VFDM). This overlay technique allows the coexistence of a downlink Orthogonal Frequency Division Multiple Access (OFDMA) macro-cell and a cognitive multi-user small-cell system. In that work, MU-VFDM was shown to be able to completely cancel the interference ...

Secondary receivers in Multiple-Input Multiple-Output (MIMO) Cognitive Radio (CR) networks combat interference from primary transmitters while equipped with whitening filters. However, when the MIMO secondary users are employing Radio Frequency (RF) beam-forming networks at the transmitter/ receiver front ends to improve the MIMO transmission performance, the whitening filters cannot perform in...

Satellite transmissions are prone to both unintentional and intentional RF interference. Such interference has significant impact on the reliability of packet transmissions. In this paper, we make preliminary steps at exploiting the sensing capabilities of cognitive radios for reliable satellite communications. We propose the use of dynamically adjusted frequency hopping (FH) sequences for sate...

Vehicle to many vehicles (V2MV) multicast is an attractive application to provide vehicle safety and traffic control information, urban sensing and multimedia content sharing in vehicular ad hoc networks. Due to the limitation of DSRC channels, Wi-Fi channels can be alternative to realize the multicast in the vehicular networks. However, the deployment using the Wi-Fi in ISM bands is challengin...

A robust resource allocation (RA) algorithm for cognitive relay networks with multiple primary users considering joint channel uncertainty and interference uncertainty is proposed to maximize the capacity of the networks subject to the interference threshold limitations of primary users’ receivers (PU-RXs) and the total power constraint of secondary user’s transmitter and relays. Ellipsoid set ...

Cognitive radio (CR) is proposed to automatically detect and exploit unused spectrum while avoiding harmful interference to the incumbent system. In this paper, we emphasize the channel capacity comparison of a CR network using two types of multicarrier communications: conventional Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix (CP) and Filter Bank based MultiCarrier (FBMC...

An interference channel is a network consisting N senders and N receivers. There exists a oneto-one correspondence between senders and receivers. Each sender only wants to communicate with its corresponding receiver, and each receiver only cares about the information form its corresponding sender. However, each channel interferes the others. So an interference channel has N principal links and ...