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Throughput scaling laws for two coexisting ad hoc networks with m primary users (PUs) and n secondary users (SUs) randomly distributed in an unit area has been widely studied. Early work showed that the secondary network performs as well as stand-alone networks, namely, the per-node throughput of the secondary networks is equation. In this paper, we show that by exploiting directional spectrum opportunities...
This paper proposes an efficient dynamic traffic allocation scheme for multi-flow distribution in LTE-WLAN heterogeneous networks, where data traffic is split into multiple sub-flows and transmitted through different networks simultaneously. The state transition equations of the M/M/1 queuing system are modified to model the parallel transmissions. To make our scheme more practical, the modified model...
Detection of wideband communication signals is critical for cognitive radio (CR) as it enables secondary users to dynamically access the unoccupied bands. However, accurate and fast spectrum sensing is still a challenge in low signal to noise ratio (SNR) environment. To encounter this problem, a feature detector based on compressed sensing (CS) and wavelet transform (WT) (CS-WT feature detector) is...
In cognitive radio networks, wideband spectrum sensing is a key requirement for cognitive radio access. Different node allocation schemes will lead to the different sensing performance between the sub-bands that compose the wideband. If the detection accuracy of some sub-band is much low, the primary user (PU) will be interfered severely. Thus, the system fairness which is measured by the minimum...
To dynamically and efficiently utilize the vacant spectrum resources, cognitive radio is proposed as a potential solution, where spectrum sensing is one of the indispensable techniques. As one of the remaining issues in spectrum sensing, how to achieve the fast and energy efficient spectrum sensing in face of a wide band spectrum with an acceptable sensing accuracy is still a big challenge. Therefore,...
In this paper we study the joint price and power allocation for interference management in macro- femto spectrum sharing network based on the Stackelberg game. In our model, the macro base station (MBS) works as leader and overlaid femto base stations (FBSs) as followers. The MBS allocates its power and interference price to the FBSs to guarantee its user's minimum rate requirement and reap the revenue...
Spectrum access opportunity is an important research topic in cognitive radio networks, which is both related to the transmission constraints from primary users and cognitive users. This paper analyses the relationship between deployment of cognitive network and mutual interference constraints from primary network to cognitive network and cognitive network itself. By utilizing the primary exclusive...
In this paper, a novel cooperative sensing based on local spatial distance sensing and reliability clustering scheme is proposed. Based on the signal propagation model, the distance between primary user and secondary user follows the logarithmic normal distribution. Then we propose a distance threshold to detect the primary user and put forward a reliability-based clustering cooperative sensing scheme,...
The secondary usage of TV white spaces by cognitive devices is a widely concerned topic in recent years. Both the Federal Communications Commission (FCC) in USA and the Electronic Communications Committee (ECC) in Europe have proposed rules to enable the secondary spectrum access in TV white spaces by geolocation database method. Geolocation database in cognitive network maintains records of all authorized...
To efficiently utilize the vacant spectrum resources, different environment awareness techniques, such as the spectrum sensing, have been applied in cognitive radio networks (CRNs). However, the existing research works ignore the effects and differences between the long term and short term vacant spectrum quality of primary users. Therefore, the cognitive information sequence (CIS) concept has been...
We consider the problem of channel allocation in cognitive radio network (CRN) with the restraints for adjacent-channel interferenc (ACI) caused by CRN, which is significant in the existing communication system and is easily ignored by researchers. In order to mitigate the effects of the adjacent-channel interference, it is a convenient way to use guard bands in CRN, when cognitive radio (CR) users...
The fast and accurate spectrum sensing over an ultra-wide bandwidth is a big challenge for the radio environment cognition. Traditional spectrum sensing technique is neither efficient nor necessary, wasting the spectrum access opportunities on the vacant spectrum holes of primary users (PUs). Considering the sparse signal feature, a novel compressed sensing technique is proposed by using the minimal...
Second order statistics (SOS) matrix has been utilized in near field source localization with an extremely low complexity. However, in practice there exits a vector matching defect seriously deteriorating the robustness of the algorithm. In this paper, we introduce the Minimum Description Length (MDL) as a data pre-processing mechanism and generate a merging algorithm with signal detection which can...
In this paper, we analyze the sensing performance of multi-cycle cyclostationary (MC) detection- based spectrum sensing in a secondary user (SU) possessing multiple correlated antennas when the channel from the primary user (PU) to the SU suffers from Nakagami fading. We first propose an improved MC detector, aiming at reducing the computational complexity of conventional MC detector by simplifying...
Spectrum access is an important research topic in cognitive radio networks, in which secondary users (SUs) manage to utilize the licensed spectrum bands of primary users opportunistically. However, there is a tradeoff between the access opportunities for SUs and communication constraints from primary networks. Moreover, considering the interplay among SUs sharing the limited spatial access resources,...
Dynamic spectrum leasing is a new spectrum sharing paradigm to achieve efficient use of the frequency resources for cognitive radio. In this paper, we propose two schemes of selecting secondary nodes as relays. Secondary users act as relays to improve quality of service of primary user, then primary user may lease a fraction of spectrum bands to secondary users. It is shown that these two schemes...
The Radio Environment Map (REM) provides an effective approach to Dynamic Spectrum Access (DSA) in Cognitive Radio Networks (CRNs). Previous results on REM construction show that there exists a tradeoff between the number of measurements (sensors) and REM accuracy. In this paper, we analyze this tradeoff and determine that the REM error is a decreasing and convex function of the number of measurements...
This paper analyzes the connectivity of cognitive radio networks. The connectivity of cognitive network which is more consistent with reality is redefined in our article and the closed-form formula of relation between connectivity and density of PUs, density of SUs, and transmission radius of SU is given. Specifically, the impact of correlation of adjacent nodes for connectivity of cognitive radio...
In this work, we present an optimal power allocation scheme dedicated for variable-hop cooperative relays in cognitive networks, which consists of Secondary users (SUs) operating in Amplify-and-Forward (AF) mode, with a Primary user (PU) receiver nearby. In order to assure the quality of service (QoS) for PU, transmit power of cognitive radio (CR) nodes must be tightly controlled which leads to narrow...
To successfully deploy multi femtocells in public places, the interference between femtocells must be mitigated. However, some unique features of femtocells present a challenge in interference mitigation, such as complex indoor wireless environment and short distance between femtocells. In this paper, a novel low cost cognitive enabled multi-element antenna solution is proposed to reduce the intra-tier...
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