With the exponential increase in the use of high powered wireless devices, there is a demand to utilize the spectrum efficiently, intelligently and optimally. Cognitive Radio is an attractive concept and solution, capable of addressing this issue. This paper investigates a statistical simulation model for spectrum sensing of cognitive radio and the associated interference probability calculatio...

For the CR systems sharing the spectrum with narrowband primary devices, this paper presents an OFDM system supporting the fractional bandwidth (FBW) mode to avoid the interference to or from the primary devices. For the system, the preamble and FBW mode detection algorithm are provided to obtain the FBW mode information during the initial synchronization. The simulation results reveal that the...

Due to the metallic structure of decks, bulkheads and watertight (WT) doors, wireless communications are a serious challenge in the particular environment of ships. In order to deploy reliable shipboard wireless networks, wireless devices (access points, routers, sensor nodes, etc) must be located at strategic locations ensuring full radio coverage and network connectivity. Strategic locations ...

A new microcell configuration scheme in urban areas is proposed in order to increase the reuse efficiency of radio resources. Multiple directional-beam antennas lined up along a street form a cigar-shaped cell. Antennas are located at intersection and are directed along the intersecting streets. Two antennas facing each other form a microzone and, therefore, a cigar-shaped cell consists of mult...

In cognitive radio networks, the licensed frequency bands of the primary users (PUs) are available to the secondary user (SU) provided that they do not cause significant interference to the PUs. In this paper, we analyzed the normalized throughput of the SU with multiple PUs coexisting under any Frequency Division Multiple Access (FDMA) communication protocol. We consider a cognitive radio tran...

A software radio receiver is one which is tuned to receive a transmitted signal on multiple communication standards through software rather than hardware. To incorporate multi-standard radio communications an intermediate frequency of high ranges is used. Such high intermediate frequencies when sampled with Nyquist rate gets oversampled due to the phenomenon of Band Pass sampling depending on t...

MIMO (multiple-input multiple-output) transmission is a promising technology to improve the frequency usage efficiency in mobile radio communications. In this letter, MIMO transmission with eigenbeam space division multiplexing (E-SDM) is focused on and the site-dependent beamforming characteristics is examined to know the transmission characteristics. Site-dependent radiowave direction of arri...

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...

This article explores the analog integration challenges in 4G base stations. Rel-12 features, such as wideband downlink CA, downlink multiple-input multiple-out (MIMO) spatial multiplexing, and AAS with embedded RF, present new design challenges in next-generation eNodeB radios. A bits-to-RF solution can help engineers shape alternative radio transmitter architectures (an example is given). The...