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1.
Vasileios K. Sakarellos Charilaos I. Kourogiorgas Dimitrios Skraparlis Athanasios D. Panagopoulos John D. Kanellopoulos 《Wireless Personal Communications》2013,71(4):2725-2740
Frequencies above 10 GHz nowadays may be employed either for backhaul networks of mobile communication access networks or for broadband fixed wireless access networks. Millimeter wave networks can afford large bandwidth by carrying the aggregate traffic through different network nodes. Consequently, many line-of-sight multi-hop transmissions may occur. At these frequency bands, rain attenuation is the dominant fading mechanism that aggravates the outage performance of these networks. The objective of this paper is the presentation of analytical models for the calculation of the end-to-end performance analysis of a triple-hop system with non-regenerative and regenerative relays using the trivariate lognormal distribution along with a physical model for the calculation of the correlation coefficients among the rain fading channels. Moreover, an accurate rain attenuation time series synthesizer based on multi-dimensional first order Stochastic Differential eqnarrays is employed in order to validate the analytical results. Finally, extended numerical results investigate the impact of various operational and geographical parameters, as well as the influence of the arbitrary position of the relays on the outage system performance. 相似文献
2.
Huy T. Nguyen Dac-Binh Ha Sang Quang Nguyen Won-Joo Hwang 《Mobile Networks and Applications》2018,23(6):1525-1538
To enhance the spectrum scarcity of cooperative heterogeneous networks (HetNets) with unreliable backhaul connections, we examine the impact of cognitive spectrum sharing over multiple small-cell transmitters in Nakagami-m fading channels. In this system, the secondary transmitters are connected to macro-cell via wireless backhaul links and communicate with the secondary receiver by sharing the same spectrum with the primary user. Integrating cognitive radio (CR) network into the system, we address the combined power constraints: 1) the peak interference power at the primary user and 2) the maximal transmit power at the secondary transmitters. In addition, to exclude the signaling overhead for exchanging channel-state-information (CSI) at the transmitters, the selection combining (SC) protocol is assumed to employ at the receivers. To evaluate the performance, we first derive the closed-form statistics of the end-to-end signal-to-noise (SNR) ratio, from which the exact outage probability, ergodic capacity and symbol error rate expressions are derived. To reveal further insights into the effective unreliable backhaul links and the diversity of fading parameters, the asymptotic expressions are also attained. The two interesting non-cooperative and Rayleigh fading scenarios are also investigated. Numerical results are conducted to verify the performance of the considered system via Monte-Carlo simulations. 相似文献
3.
马忠彧马宏锋彭琳茹刘馨 《微波学报》2019,35(2):81-86
为精确分析具有线性视距(LOS)传输特性的5G 毫米波自回传网络(mW-SBN)中阻塞问题的中断性能,提出了基于随机几何和随机形状理论的毫米波自回传网络中断分析方法。推导了毫米波宏基站(MBS)和微小区(SC)之间距离的统计特性,以及mW-SBN 回传链路中断概率的闭型表达式,得出了mW-SBN 网络参数与回传链路中断概率的关系式。仿真和计算结果表明:mW-SBN 回传链路中断概率主要受MBS 与SC 之间距离及表征阻塞物大小和形状的参数等系统参数影响,仿真结果也印证了得出的理论分析。 相似文献
4.
Vasileios K. Sakarellos Charilaos Kourogiorgas Athanasios D. Panagopoulos 《Wireless Personal Communications》2014,79(2):1471-1481
Next generation communication networks incorporate Land Mobile Satellite (LMS) systems in order to provide greater areas of coverage and higher throughput for specific applications. Cooperation between satellite communication networks and terrestrial relays is or increasing the system’s performance and availability. In this paper, the outage performance of a cooperative hybrid satellite and terrestrial system configuration is analytically evaluated assuming that the satellite links suffer from shadowed Rician fading, while the terrestrial link suffers from the Nakagami-m fading. Two cooperative relaying strategies are examined and the final formulas for the calculation of the outage probability are given. Moreover, a block diagram for the generation of time series for the reliable simulations of the outage probability of the cooperative hybrid land mobile satellite systems is given. The theoretical results and the simulation results almost coincide. Moreover, extended numerical results investigate the impact, of different shadowing conditions and more generally of the satellite links elevation angles, on the overall cooperative LMS system performance. 相似文献
5.
Khuong Ho-Van 《Wireless Networks》2016,22(7):2131-2141
This paper provides a general outage analysis framework for cooperative cognitive networks with proactive relay selection over non-identical Rayleigh fading channels and under both maximum transmit power and interference power constraints. We firstly propose an exact closed-form outage probability expression, which is then exploited for determining the diversity order and coding gain for proactive relay selection scenarios as well as deriving system performance limits at either large maximum transmit power or large maximum interference power. The derived performance metrics bring several insights into system performance behavior without the need of time-consuming Monte-Carlo simulations. Various results confirm the validity of the proposed derivations and show that cooperative cognitive networks with proactive relay selection incur performance saturation and their performance depends considerably on the number of involved relays. In addition, cooperative cognitive networks are significantly better than dual-hop counterparts without any cost of system resources. 相似文献
6.
Khuong Ho-Van 《Wireless Personal Communications》2013,70(2):1001-1009
Our contribution in this paper is the derivation of an exact closed-form outage probability formula for underlay cognitive cooperative networks operated over Rayleigh fading channels. The derivation considers the correlation among received signal-to-noise ratios, two critical constraints (interference power constraint and maximum transmit power constraint), and non identically distributed (i.d.) channels. The derived formula is corroborated by Monte Carlo simulations and is served as an useful and effective tool to evaluate the performance behavior of underlay cognitive cooperative networks without time-consuming simulations under different operation parameters. Numerical results illustrate that underlay cognitive cooperative networks suffer the outage saturation phenomenon for a given maximum interference power level. 相似文献
7.
Ultra‐dense network (UDN) is one of candidate technologies for next generation cellular networks. In this paper, we explore performance limits of cooperative UDN with maximal ratio‐combining detection under limited‐capacity backhaul links. More concretely, based on the imperfect estimation, lower bounds of the average per‐user rate are derived for maximal ratio‐combining detection with and without successive interference cancellation scheme when the number of Base stations (BSs) in the network goes to infinite. Then we discuss how the average per‐user rate is impacted by the number of cooperative BSs and the backhaul capacity. Our results show that there is an optimal number of cooperative BSs in the UDN to achieve the best performance in low signal‐to‐noise‐ratio region. Simulations demonstrate that our asymptotic rate bounds are tight when the number of BSs is large. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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9.
Ramachandran Vijayarani Lakshmanan Nithyanandan 《Wireless Personal Communications》2017,92(2):667-679
Coordinated Multi-Point (CoMP) transmission is a technique proposed to enhance the spectral efficiency and system throughput in an interference limited cellular networks. In CoMP joint processing (JP) scheme multiple base stations (BSs) are coordinately transmit data streams to each user. As more than two base stations are involved, abundant spatial resources are exploited and more backhaul spectrum for JP cooperation is required. The backhaul architecture for CoMP JP is crucial to provide low latency, unlimited capacity, less power consumption, and perfect synchronization among the BSs. However, satisfying all these constraints is impossible as the number of cooperative BSs increases for each user. In this paper, a dynamic cooperative base station selection scheme is proposed to reduce the backhaul load for CoMP user by selecting the appropriate number of coordinated BSs from the CoMP cluster to ensure the certain quality of service (QoS). In particular, for cell edge user the number of cooperative BSs per user has been selected in order to achieve reduced overhead and the allocation of backhaul capacity is performed under the max–min fairness criterion. Simulation results show that the proposed selection scheme achieves significant performance improvement than other transmission modes in terms of the average sum rate per backhaul use and minimal total power consumption. 相似文献
10.
Performance Analysis of OSTBC Transmission in Amplify-and-Forward Cooperative Relay Networks 总被引:1,自引:0,他引:1
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提出一种多中继协同无线网络的机会编码协同策略,该策略基于Turbo编码,利用信道条件信息机会选择最优协同节点。通过数学分析,给出了系统中断性能和瑞利衰落下的中断概率表达式,计算机仿真结果进一步揭示了机会编码协同相对于传统编码协同的优势。 相似文献
13.
Woradit K. Quek T.Q.S. Suwansantisuk W. Wymeersch H. Wuttisittikulkij L. Win M.Z. 《Wireless Communications, IEEE Transactions on》2009,8(8):3890-3895
Cooperative diversity techniques can improve the transmission rate and reliability of wireless networks. For systems employing such diversity techniques in slow-fading channels, outage probability and outage capacity are important performance measures. Existing studies have derived approximate expressions for these performance measures in different scenarios. In this paper, we derive the exact expressions for outage probabilities and outage capacities of three proactive cooperative diversity schemes that select a best relay from a set of relays to forward the information. The derived expressions are valid for arbitrary network topology and operating signalto- noise ratio, and serve as a useful tool for network design. 相似文献
14.
In this paper, we propose a cooperative transmission scheme using quasi-orthogonal space-time block codes (QOSTBCs) for multiple-input
multiple-output (MIMO) relay networks. Comparing with the conventional cooperative transmission scheme using orthogonal space-time
block codes (OSTBCs), the proposed scheme can achieve higher bandwidth efficiency with the same decoding complexity. Moreover,
an adaptive decode-and-forward (ADF) relaying protocol is proposed based on one-bit channel state information (CSI) feedback.
According to the CSI feedback, a better transmission mode can be selected between the direct transmission and decode-and-forward
(DF) cooperative transmission. In addition, the outage performance of the proposed scheme is investigated and a closed-form
upper bound on the outage probability is derived. The performance analysis shows that the proposed scheme can achieve a full
diversity order, which is higher than that of the direct and DF cooperative transmissions. 相似文献
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In relay-assisted cellular networks, mobile stations are connected to base station through two or more single-hop communication links, where the intermediate nodes act as relay stations (RSs). The focus of this paper is on two-hop relay assisted cellular networks, where optimal relay placement is a crucial issue for achieving maximum extension of the cell coverage. However, the location of RS has significant impact on signal-to-interference plus noise ratio (i.e., SINR) and outage probability experienced on the access and backhaul links. Moreover, the frequency re-use factor also has significant influence on the SINR. In this paper, we develop analytical models for computing the SINR and outage probability performance of a two-hop relay assisted cellular network for both downlink (DL) as well as uplink (UL) transmission scenarios, considering the impact of path loss, shadowing, Nakagami fading and co-channel interference. We then investigate optimal placement of RS while satisfying the required criterion on probability of correct decoding, initially by considering the DL scenario alone and then by considering both DL and UL scenarios jointly. Through extensive evaluations, we report the impact of realistic propagation models on outage probability, optimal relay position and the cell coverage radius. Further, the model can be used to find the impact of co-channel re-use factor on optimal relay positioning in two-hop cellular networks. 相似文献
17.
Recently, energy-efficient (EE) communications have received increasing interest specially in cellular networks. Promising techniques, such as multiple input multiple output (MIMO) and base station (BS) cooperation schemes, have been widely studied in the past to improve the spectral efficiency and the reliability. Nowadays, the purpose is to investigate how these techniques can reduce the energy consumption of the systems. In this paper, we address for a single-user scenario, the energy efficiency of two BSs cooperation under limited backhaul capacity. In order to evaluate the EE metric, we provide first an information-theoretical analysis based on the outage probability, for a quantization model over the backhaul. Then, we extend this EE analysis to a more practical approach with data transmission over the backhaul. For both approaches, we identify by numerical/simulation results the cooperation scenarios that can save energy depending on the backhaul capacity. 相似文献
18.
We consider infrastructure-based amplify-and-forward (AF) relaying for extending downlink and uplink coverage areas of a cellular
base station. The base station serves multiple mobile users via a multi-hop backhaul relay link by sharing out access link
channel resources with maximum signal-to-noise ratio (SNR) scheduling. We analyze the performance of the system by deriving
closed-form expressions for outage probability, outage capacity, ergodic capacity, average end-to-end SNR and amount of fading
(AoF). These measures show that maximum SNR scheduling of multiple users in a cellular relay link offers significant diversity,
capacity and SNR improvement over single-user transmission and round robin scheduling. We also relate performance of the relay
link to that of a distributed antenna system (DAS), and show that the noisy wireless backhaul relay link induces tolerable
performance deterioration compared to deploying a cable-connected distributed antenna. 相似文献
19.
In this paper, we investigate the outage performance of OFDM-based selective decode-and-forward cooperative networks over
independent but not necessarily identically distributed (i.n.i.d.) Nakagami-m fading channels, with integer values of parameter m. A unified closed-form expression for the outage probability is derived for three selective relaying schemes. The effect
of the coherence bandwidth on the proposed scheme is also investigated. Monte Carlo simulations are carried out to validate
our analysis. 相似文献
20.
Recent work has shown that multicell cooperative signal processing in cellular networks can significantly increase system capacity and fairness. For example, multicell joint transmission and joint detection can be performed to combat intercell interference, often mentioned in the context of distributed antenna systems. Most publications in this field assume that an infinite amount of information can be exchanged between the cooperating base stations, neglecting the main downside of such systems, namely, the need for an additional network backhaul. In recent publications, we have thus proposed an optimization framework and algorithm that applies multicell signal processing to only a carefully selected subset of users for cellular systems with a strongly constrained backhaul. In this paper, we consider the cellular downlink and provide a comprehensive summary and extension of our previous and current work. We compare the performance obtained through centralized or decentralized optimization approaches, or through optimal or suboptimal calculation of precoding matrices, and identify reasonable performance–complexity trade-offs. It is shown that even low-complexity optimization approaches for cellular systems with a strongly constrained backhaul can yield major performance improvements over conventional systems. 相似文献