A Chunk by chunk-based allocation is an emerging subcarrier allocation in Single Carrier Frequency Division Multiple Access (SC-FDMA) due to its low complexity. In this paper, a combined userorder and chunk-order allocation for solving chunk allocation problem which minimizes the average BER of all users while improving the throughput in SC-FDMA uplink is proposed. The subcarrier grouping into ...

A cognitive radio-based spectrum allocation scheme using an active cooperative-aware mechanism is proposed in this paper. The scheme ensures that the primary user and secondary users cooperate actively for their own benefits. The primary user releases some spectrum resources to secondary users to actively stimulate them to actively join the cooperative transmission of the primary user, and seco...

In the cognitive radio system, the rationalization of spectrum allocation can be improved by the spectrum prediction algorithm. In recent years, the researches of spectrum prediction focus on how to predict channel status. In order to improve spectrum utilization and reduce frequency of channel switching, a novel spectrum prediction mechanism is designed, which use Chaos Neural Network to analy...

The interference temperature (IT) model offers a novel way to perform spectrum allocation and management. Recent research has proposed schemes that take advantage of the model; however, there are still lingering questions about what exactly IT means, and how it should be measured. The temperature characterization may make sense for thermal noise, but interference behaves differently. This resea...

The rapid development of wireless communication technologies results in the problem of radio spectrum shortage. Additionally, the traditional fixed spectrum allocation scheme can lead to the significant spectrum underutilization. Cognitive radio (CR) is an emerging technology to solve those problems by enabling unlicensed users to opportunistically access the available licensed bands in an inte...

A number of recent advances in the physical layer are enabling wireless communications devices to reach ever-greater speeds. These developments in modulation techniques, coding, and radio architecture enable better spectrum allocation, more power-efficient, error-resistant transmissions, and more flexible architectures for receiving signals. Many of the advances are being included in upcoming s...

Cognitive radio is a communication technology which is designed to serve users to make use of the available bandwidth in a greatest possible amount. Though more research has been done on spectrum sensing and allocation problems, cognitive radio has recently attracted a lot of research interest. This paper shows the concept of cognitive radio networks (CRNs). Cognitive radio is an intelligent fo...

Orthogonal Frequency Division Multiplexing (OFDM) is used for both 802.11 and 802.16 wireless network standards and is being evaluated for Fourth Generation (4G) networks such as those being proposed in the 3GPP and 3GPP2 wireless standards bodies. In both uplink and downlink directions, resources can be allocated in three dimensions, frequency, time and power. The uplink resource allocation pr...

Cognitive Radio is gaining popularity and acceptance all over the world as an efficient way to utilise the limited wireless spectrum resources. Out of the many design requirements of Cognitive Radio such as spectrum sensing, spectrum allocation, power control etc., spectrum sharing is one of main challenges to ensure peaceful co-existence of the primary and secondary users. Since multiple users...

Gateway link is essential to connect HAPS platform to terrestrial based networks. This crucial link is incorporated in HAPS fixed service spectrum allocation in considerably high frequencies, renders the link for more attenuations by atmospheric gases, and rain effects, especially when the regional climate is not favorable. However, under the agenda item 1.20 of World Radio Conference-2012 (WRC...