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2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)最新文献

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Information theoretic analysis of cooperative relay in cognitive radio 认知无线电中协同中继的信息论分析
2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS) Pub Date : 2009-12-01 DOI: 10.1109/UKIWCWS.2009.5749404
R. Rashid, N. Aripin, N. Fisal, S. Yusof
{"title":"Information theoretic analysis of cooperative relay in cognitive radio","authors":"R. Rashid, N. Aripin, N. Fisal, S. Yusof","doi":"10.1109/UKIWCWS.2009.5749404","DOIUrl":"https://doi.org/10.1109/UKIWCWS.2009.5749404","url":null,"abstract":"Motivated by the inefficient usage of the licensed spectrum across many frequency bands, cognitive radio (CR) was proposed to promote the spectrum utilization by opportunistically exploiting the existence of spectrum “holes.” Under this new paradigm, cognitive (unlicensed) user is allowed unobtrusive access to a channel exhibiting negligible primary (licensed) user activity. Cooperative communication is increasingly regarded as a way to address hidden terminal issues and to improve spatial diversity for the same spectrum frequency band. In this paper, we investigate two scenarios of cooperation: cooperative transmission of primary traffic by cognitive users (cognitive relaying) and cooperative transmission between cognitive nodes. The first scenario focuses on one cognitive transmitter which has the option to relay traffic of the primary assuming that the primary is oblivious to its presence and thus exclude the possibility of spectrum leasing. While the latter investigates a spectrum-rich node that is selected as the relay node to improve the performance between the source and the destination. To demonstrate the feasibility and performance of cooperative relay for cognitive radio, numerical results based on information theory approach are provided in order to discuss the advantages and limits of the two strategies.","PeriodicalId":198556,"journal":{"name":"2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131940848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Collaborative spectrum sensing: Optimising the number of collaborating users 协同频谱感知:优化协作用户的数量
2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS) Pub Date : 2009-12-01 DOI: 10.1109/UKIWCWS.2009.5749394
K. Arshad, K. Moessner
{"title":"Collaborative spectrum sensing: Optimising the number of collaborating users","authors":"K. Arshad, K. Moessner","doi":"10.1109/UKIWCWS.2009.5749394","DOIUrl":"https://doi.org/10.1109/UKIWCWS.2009.5749394","url":null,"abstract":"In the IEEE 802.22 standard, the spectrum sensing mechanism is identified as a key functionality of a cognitive radio. Due to the channel uncertainty, a single cognitive user, in most cases, can not make a reliable decision and hence collaboration or cooperation of and among multiple users is required. However, when large number of cognitive users are collaborating with each other, the bandwidth requirements for sending their result to the fusion centre tends to be very large. In this paper, a metric for spectrum efficiency is defined and used for the optimisation of collaborative spectrum sensing. An optimisation algorithm is presented to calculate the optimal number of collaborating cognitive users with the aim to maximise overall spectrum efficiency by satisfying certain constraints in terms of global probability of detection and probability of false alarm. Numerical results show that for maximum spectrum efficiency collaboration of only a subset of the available cognitive users is required.","PeriodicalId":198556,"journal":{"name":"2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131204923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Outage behavior of MIMO cognitive radio fading channels: A causal approach MIMO认知无线电衰落信道的中断行为:因果分析
2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS) Pub Date : 2009-12-01 DOI: 10.1109/UKIWCWS.2009.5749416
Md. Zahurul I. Sarkar, T. Ratnarajah, M. Sellathurai
{"title":"Outage behavior of MIMO cognitive radio fading channels: A causal approach","authors":"Md. Zahurul I. Sarkar, T. Ratnarajah, M. Sellathurai","doi":"10.1109/UKIWCWS.2009.5749416","DOIUrl":"https://doi.org/10.1109/UKIWCWS.2009.5749416","url":null,"abstract":"In this paper, we study a Multiple-Input Multiple-Output (MIMO) communication scenario through Rayleigh fading cognitive radio channel in which two users, called the primary and the secondary (cognitive) users wish to communicate with two different receivers, subject to the mutual interference. The cognitive user has the causal knowledge of the message being sent by the primary user and is allowed to reuse the channel during both the idle and active periods of the primary user, as long as the primary rate remains to a particular outage rate. Here, we characterize the limits of transmission rate at which the cognitive user can reliably communicate with its receiver compensating interference to the primary user by transmitting a combined information consists of its own and primary user's information using superposition coding during the active periods of primary user. Our results show that not only cognitive user gets a non-zero outage capacity but also the outage performance of primary user is improved due to the additional diversity obtained via relaying.","PeriodicalId":198556,"journal":{"name":"2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125432919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Performance of Concatenated Complete Complementary code in CDMA systems 码分多址系统中串联完全互补码的性能
2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS) Pub Date : 2009-12-01 DOI: 10.1109/UKIWCWS.2009.5749420
G. Suchitra, M. Valarmathi
{"title":"Performance of Concatenated Complete Complementary code in CDMA systems","authors":"G. Suchitra, M. Valarmathi","doi":"10.1109/UKIWCWS.2009.5749420","DOIUrl":"https://doi.org/10.1109/UKIWCWS.2009.5749420","url":null,"abstract":"Performance of a newly proposed Concatenated Complete Complementary code (CCC) in CDMA systems is studied in this work. This code has good autocorrelation and cross correlation properties when compared with the existing unitary codes such as Gold codes, Walsh codes, Kasami codes etc. Performance evaluation of the proposed CCC in DS-CDMA, MC-CDMA and STBC-CDMA systems in an AWGN channel is studied. The proposed CCC achieves a significant increase in the processing gain resulting in better Bit Error Rate performance. The proposed CCC is generated using the traditional Walsh Hadamard transform (WHT). The suitability and application of Haar transforms which are frequently applied in image processing domain are explored in the generation of CCC as a novelty in this work. The simulation results obtained shows a better performance for CCC generated using Haar transform. The proposed system can be applied in cognitive radio terminals to improve its performance.","PeriodicalId":198556,"journal":{"name":"2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116780441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Design issues in wide scanning range cognitive radios 大扫描范围认知无线电的设计问题
2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS) Pub Date : 2009-12-01 DOI: 10.1109/UKIWCWS.2009.5749402
V. Girish, Anoop C. Nair, G. Visweswaran
{"title":"Design issues in wide scanning range cognitive radios","authors":"V. Girish, Anoop C. Nair, G. Visweswaran","doi":"10.1109/UKIWCWS.2009.5749402","DOIUrl":"https://doi.org/10.1109/UKIWCWS.2009.5749402","url":null,"abstract":"Cognitive radios are being looked upon as the solution for the spectrum scarcity problem. Mitigating spectrum scarcity requires robust spectrum sensing receivers and frequency adaptive transmitters. Wideband cognitive radios are more attractive as they provide a wider range of secondary communication opportunities. They are accompanied by issues at the frontend architecture level, baseband distribution and spectrum sensing in the receivers. At a network level, the success of wideband cognitive radios are dependent on the network topology. This paper discusses these problems and provides guidelines for solving them.","PeriodicalId":198556,"journal":{"name":"2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114719491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Robust orthogonal space-time block coding scheme for use in asynchronous cooperative relay networks 异步协同中继网络中的鲁棒正交空时分组编码方案
2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS) Pub Date : 2009-12-01 DOI: 10.1109/UKIWCWS.2009.5749423
F. T. Alotaibi, J. Chambers
{"title":"Robust orthogonal space-time block coding scheme for use in asynchronous cooperative relay networks","authors":"F. T. Alotaibi, J. Chambers","doi":"10.1109/UKIWCWS.2009.5749423","DOIUrl":"https://doi.org/10.1109/UKIWCWS.2009.5749423","url":null,"abstract":"In this paper, we present a novel extended orthogonal space-time block code (EO-STBC) scheme for a cooperative relay system with four relay nodes and without perfect synchronization. Full-rate and full-diversity can be achieved through using feedback channels. The relay nodes forward information symbols in a simple amplify-and-forward (AF) manner. The information symbols can be extracted with simple symbol-wise maximum-likelihood decoding.","PeriodicalId":198556,"journal":{"name":"2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130566392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
BER performance of regenerative multi-antenna cooperative relay network in Rayleigh fading channel 瑞利衰落信道下再生多天线协同中继网络的误码率性能
2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS) Pub Date : 2009-12-01 DOI: 10.1109/UKIWCWS.2009.5749391
H. Katiyar, R. Bhattacharjee
{"title":"BER performance of regenerative multi-antenna cooperative relay network in Rayleigh fading channel","authors":"H. Katiyar, R. Bhattacharjee","doi":"10.1109/UKIWCWS.2009.5749391","DOIUrl":"https://doi.org/10.1109/UKIWCWS.2009.5749391","url":null,"abstract":"BER performance of cooperative relay network, employing infrastructure based fixed relays having multiple antennas has been investigated. Closed form expression for average BER has been derived, when destination is assumed to perform selection combining of the signals, received from direct path and through relay path. BER expressions are derived for both the cases of selection and maximum ratio combining at the relay terminal. The effect of relay placement on the system performance has also been studied under different path loss conditions.","PeriodicalId":198556,"journal":{"name":"2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130502689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 14
Outage analysis of causal cognitive radio channel 因果认知无线电信道的中断分析
2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS) Pub Date : 2009-12-01 DOI: 10.1109/UKIWCWS.2009.5749415
F. Khan, T. Ratnarajah, M. Sellathurai, S. Prakriya
{"title":"Outage analysis of causal cognitive radio channel","authors":"F. Khan, T. Ratnarajah, M. Sellathurai, S. Prakriya","doi":"10.1109/UKIWCWS.2009.5749415","DOIUrl":"https://doi.org/10.1109/UKIWCWS.2009.5749415","url":null,"abstract":"In this paper, we first analyze the outage performance of two user cognitive radio channel where the cognitive user causally obtains primary user's message knowledge. Specifically, we consider cognitive rayleigh fading channel where the cognitive user uses superposition coding to relay the primary user's message to compensate for the interference caused by its own transmission to the primary receiver. We find the mutual information expressions at primary and cognitive receivers by classifying it in different cases. Results show that non-zero capacity is obtained at cognitive receiver while maintaining outage rate of the primary unchanged. It is also shown that additional diversity is obtained at primary receiver due to relaying by the cognitive user. We then extend the single user case to multiple cognitive users. It is shown that using multiuser diversity effect and cognitive users cooperation, significant increase in the mutual information at cognitive receiver for a given outage probability is achieved.","PeriodicalId":198556,"journal":{"name":"2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123409373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Cooperative change detection using physical layer fusion 基于物理层融合的协同变化检测
2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS) Pub Date : 2009-12-01 DOI: 10.1109/UKIWCWS.2009.5749397
Mustafa Khandwawala, Nirmal V. Shende, C. Murthy
{"title":"Cooperative change detection using physical layer fusion","authors":"Mustafa Khandwawala, Nirmal V. Shende, C. Murthy","doi":"10.1109/UKIWCWS.2009.5749397","DOIUrl":"https://doi.org/10.1109/UKIWCWS.2009.5749397","url":null,"abstract":"This work presents a new approach to spectrum sensing for cognitive radios with multiple sensors under a change detection framework. Physical layer fusion is used at the fusion center in order to implement a cumulative sum based change detection algorithm. Two channel models, AWGN and quasi static block-fading, are considered for the channel between the sensors and the fusion center. Analytical expressions are obtained for determining the false alarm rate and worst case detection delay performance. Simulation results are presented to highlight the performance of the scheme. It is shown that this scheme achieves a performance close to that of a centralized change detection scheme in the case of an AWGN channel.","PeriodicalId":198556,"journal":{"name":"2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116784898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On the performance of cooperative DS CDMA system using distributed space time spreading 基于分布式时空扩展的合作DS CDMA系统性能研究
2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS) Pub Date : 2009-12-01 DOI: 10.1109/UKIWCWS.2009.5749413
Rajeev Gangula, R. Bhattacharjee
{"title":"On the performance of cooperative DS CDMA system using distributed space time spreading","authors":"Rajeev Gangula, R. Bhattacharjee","doi":"10.1109/UKIWCWS.2009.5749413","DOIUrl":"https://doi.org/10.1109/UKIWCWS.2009.5749413","url":null,"abstract":"In this contribution we propose and analyze a cooperative diversity protocol using distributed space-time spreading (DSTS), for the uplink direct-sequence code division multiple access (DS-CDMA) system, where one source mobile terminal communicates with destination with the assistance of two relay terminals. We assume that the communication channels experience independent and identical flat fading modeled correspondingly by Rayleigh distribution. While using DSTS, we consider the effect of intermediate decision errors at the relay terminals.","PeriodicalId":198556,"journal":{"name":"2009 First UK-India International Workshop on Cognitive Wireless Systems (UKIWCWS)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129724594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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