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An important step in the initialization of a wireless ad hoc network is neighbor discovery in which every node attempts to determine the set of nodes it can communicate with in one wireless hop. In recent years, cognitive radio technology has gained attention as an attractive approach to alleviate the congestion within the frequency spectrum. A cognitive radio transceiver can operate over a wide range...
Most current and upcoming communication systems like 802.11x, WiMAX etc. deploy some variant of Orthogonal Frequency Division Multiplexing as their physical layer technology. Symbol timing acquisition is the first operation performed at the receiver after which other signal processing, such as orthogonalizing the received data into parallel streams using Fast Fourier Transform (FFT), can take place...
Cognitive radio (CR) technology is a promising emerging technology that enables a more efficient usage of already assigned spectrum. However, before CR networks can be deployed, new algorithms and protocols need to be developed. When forming an ad-hoc cognitive radio network (CRN), one of the fundamental tasks is to determine the neighbors of each node and channels that can be used to communicate...
Cognitive radios (CR) have the ability to dynamically adapt to local spectrum availability. In a network comprised of CR-enabled devices, layer-2 auto-configuration involves determining a common set of channels to facilitate communication among participating nodes. This is a unique challenge as nodes in the CR network may be unaware of (a) their neighbors and (b) the channels on which they can communicate...
Cognitive radio (CR) offers a new mechanism for flexible usage of radio spectrum. This paper presents a full-duplex multi-channel MAC protocol designed for CR enabled multi-hop networks. Each node is equipped with at least two transceivers, one for transmitting and another for receiving. A node selects an unused frequency band as its home channel (HCh) and tunes its receiver to its HCh. When a node...
Cognitive radios (CR) have the ability to dynamically adapt to local spectrum availability. In a multi-hop wireless network comprised of CR-enabled devices, medium access control (MAC) layer scheduling for data communication involves assignment of timeslots and channels to either links or nodes in the network. The number of channels available and the channel identities vary from one node to another...
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