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In this paper, we investigate the detection of long-term evolution (LTE) single carrier-frequency division multiple access (SC-FDMA) signals, with application to cognitive radio systems. We explore the second-order cyclostationarity of the LTE SC-FDMA signals and apply results obtained for the cyclic autocorrelation function to signal detection. The proposed detection algorithm provides a very good...
In opportunistic spectrum access (OSA), not all the spectrum holes detected by Secondary System (SS) are available for SS users. Spectrum analysis is a required step before SS users access the detected spectrum holes in data slot. SS should make sure that the quality of service (QoS) of primary system (PS) users would still be acceptable after SS accessed the spectrum holes. This paper proposes a...
In this paper we study the role of control/status channel in MAC protocol of cognitive radio networks. To this end we consider three channel access schemes of IEEE 802.11 DCF namely (i) the Basic Access mechanism that uses no control channel and (ii) RTS-CTS mechanism, that uses a control channel for contention and (iii) cooperative Basic Access scheme that uses a dedicated channel for status update...
The static frequency allocation in wireless communication became a major issue for an efficient spectrum utilization. Also some of the frequency channels are not fully utilized because of spatial and temporal variations. Hence the focus of the new spectrum management policies is dynamic spectrum access (DSA) technology based on cognitive radio (CR). Spectrum mobility is considered to be the next big...
In cognitive radio (CR) networks, unlicensed users (or secondary users, SUs) can explore and exploit white spaces, which are the underutilized licensed channels, conditional on acceptable interference to the licensed users (or primary users, PUs). This paper investigates the effects of network characteristics on the network performance of a routing scheme called Cognitive Radio Q-routing (CRQ-routing),...
Cognitive radio (CR) has been proposed to enable unlicensed users (or secondary users, SUs) to exploit the underutilized licensed channels (or white spaces) owned by the licensed users (or primary users, PUs). This article presents a simple and pragmatic reinforcement learning (RL)-based routing scheme called Cognitive Radio Q-routing (CRQ-routing). CRQ-routing is a spectrum-aware scheme that finds...
In this paper, the effect of multiple spectrum handoffs on data delivery time of Secondary Users (SU) in Cognitive Radio (CR) networks are investigated. Whenever a Primary User (PU) appears on a licensed channel, the spectrum handoff procedure is initiated to interrupt the SU and the channel must be released for PU's transmission. In this paper, the rate of handoff occurrence is investigated and the...
Recently, cognitive pilot channel (CPC) has been proposed to assist spectrum awareness and network selection in the heterogeneous network and dynamic spectrum access mechanism. The CPC channel can provide the necessary wireless environment information for the terminals and avoid long time- and energy-consumption for spectrum scanning. In previous researches, two different CPC information delivery...
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