{"title":"Soft Metric Assisted Mobility Robustness Optimization in LTE Networks","authors":"Gao Hui, P. Legg","doi":"10.1109/ISWCS.2012.6328318","DOIUrl":"https://doi.org/10.1109/ISWCS.2012.6328318","url":null,"abstract":"Mobility Robustness Optimization (MRO) is a use-case of Self-Organizing Networks (SON) for LTE that aims to optimize handover performance automatically. Conventional MRO algorithms tune handover parameters based on counts of handover failures and handover events. The algorithm requires many handovers per cell pair (e.g. 1000) to trigger a reliable adjustment. Thus it can result in a slow adaptation to changes that improve or deteriorate handover performance, such as network loading or UE speed. In this paper, we propose a new MRO algorithm taking into account soft metrics, such as handover command transmission time, derived both from failed and successful handovers. The proposed algorithm provides a faster reaction and lower failure rate than the conventional method, with no deterioration in the handover count.","PeriodicalId":167119,"journal":{"name":"2012 International Symposium on Wireless Communication Systems (ISWCS)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121654007","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}
R. Ratasuk, M. Uusitalo, N. Mangalvedhe, Antti Sorri, S. Iraji, C. Wijting, Amitava Ghosh
{"title":"License-exempt LTE deployment in heterogeneous network","authors":"R. Ratasuk, M. Uusitalo, N. Mangalvedhe, Antti Sorri, S. Iraji, C. Wijting, Amitava Ghosh","doi":"10.1109/ISWCS.2012.6328367","DOIUrl":"https://doi.org/10.1109/ISWCS.2012.6328367","url":null,"abstract":"Mobile broadband data usage in Long Term Evolution (LTE) networks is growing exponentially and capacity constraint is becoming an issue. Heterogeneous network, WiFi offload, and acquisition of additional radio spectrum can be used to address this capacity constraint. Licensed spectrum, however, is limited and can be costly to obtain. This paper investigates deploying LTE on a license-exempt band as part of the pico-cell underlay. Coexistence mechanism and other modifications to LTE are discussed. Performance analysis shows that LTE can deliver significant capacity even while sharing the spectrum with WiFi systems.","PeriodicalId":167119,"journal":{"name":"2012 International Symposium on Wireless Communication Systems (ISWCS)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126919997","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}
Georges Kaddoum, J. Olivain, G. B. Samson, P. Giard, F. Gagnon
{"title":"Implementation of a Differential Chaos Shift Keying communication system in GNU radio","authors":"Georges Kaddoum, J. Olivain, G. B. Samson, P. Giard, F. Gagnon","doi":"10.1109/ISWCS.2012.6328505","DOIUrl":"https://doi.org/10.1109/ISWCS.2012.6328505","url":null,"abstract":"In this paper the first experimental chaos radio system using Differential Chaos Shift Keying is realized. The software design and implementation are proposed for the experimental Differential Chaos Shift Keying (DCSK) system on software defined radio (SDR) to perform in a real-time wireless transmission. The GNU Radio platform is used as a flexible and open-source platform for our implementation. In order to perform in real-time wireless scenarios, the proposed work implements a synchronization unit on the receiver side. Since our system is on a SDR, the bitrate, bandwidth and central frequency can be modified at ease. The experimental performance are discussed and compared to the theoretical predictions. Finally some trends concerning implementation are discussed.","PeriodicalId":167119,"journal":{"name":"2012 International Symposium on Wireless Communication Systems (ISWCS)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127165529","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}
{"title":"Impact of RF front-end nonlinearity on WSN Communications","authors":"Amine Didioui, C. Bernier, D. Morche, O. Sentieys","doi":"10.1109/ISWCS.2012.6328493","DOIUrl":"https://doi.org/10.1109/ISWCS.2012.6328493","url":null,"abstract":"In this paper, we study the impact of RF-front end nonlinearity on the performance of wireless sensor networks (WSN). More specifically, we investigate the problem of interference caused by intermodulation between in-band interferers. We analyze this problem using an enhanced model of signal-to-interference-and-noise ratio (SINR) that includes an interference term due to intermodulation. Using a WSN simulator and the selectivity and the third-order input intercept point (IIP3) specifications of a radio transceiver, we show that the new SINR model provides helpful information for the analysis of intermodulation problems caused by in-band signals in IEEE 802.15.4 WSNs.","PeriodicalId":167119,"journal":{"name":"2012 International Symposium on Wireless Communication Systems (ISWCS)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127257646","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}
{"title":"Capacity gains due to orthogonal spectrum sharing in multi-operator LTE cellular networks","authors":"Luca Anchora, L. Badia, E. Karipidis, M. Zorzi","doi":"10.1109/ISWCS.2012.6328375","DOIUrl":"https://doi.org/10.1109/ISWCS.2012.6328375","url":null,"abstract":"Static spectrum allocation leads to resource wastage and inter-operator spectrum sharing is a possible way to improve spectrum efficiency. In this work, we assume that two cellular network operators agree upon sharing part of their spectrum, which can then be dynamically accessed by either of them in a mutually exclusive way. Our goal is to numerically assess the gain, in terms of cell capacity, due to such orthogonal spectrum sharing. Hence, we propose a centralized algorithm that performs coordinated scheduling, in order to numerically evaluate an upper bound on the achievable sum capacity. The algorithm is centralized and exploits complete information on both networks to perform the optimum allocation. The simulation results illustrate the impact of the multiuser diversity and the asymmetry in the traffic load among the networks on the overall achievable gain.","PeriodicalId":167119,"journal":{"name":"2012 International Symposium on Wireless Communication Systems (ISWCS)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126516365","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}
{"title":"Performance comparison of signal strength and signal quality based Inter-RAT MRO","authors":"A. Awada, B. Wegmann, I. Viering, A. Klein","doi":"10.1109/ISWCS.2012.6328320","DOIUrl":"https://doi.org/10.1109/ISWCS.2012.6328320","url":null,"abstract":"The Long Term Evolution (LTE) network is currently being deployed on top of the legacy radio access technologies (RATs) such as the second generation (2G) or third generation (3G) mobile networks. Inter-RAT mobility robustness optimization (MRO) is one of the most important use cases for self-organizing network (SON). Unlike the manual optimization methods, an inter-RAT MRO algorithm adjusts the handover thresholds of each cell in autonomous and automatic manner. An inter-RAT handover is triggered when a measurement event is received from a user equipment (UE). The measurement event can rely on different measurement quantities, namely either signal strength (SS) or signal quality (SQ), where SQ takes the interference experienced by the UE into account. This paper investigates the sensitivity of the two measurement quantities on the behavior of the inter-RAT MRO algorithm in terms of optimization performance. Results have shown that SS is a more robust measurement quantity than SQ as it yields lower numbers of inter-RAT handovers and mobility failure events. Moreover, inter-RAT MRO is needed to achieve the best performance in each cell for both SS and SQ measurement quantities even though the optimization range of the handover thresholds is relatively small for the latter case.","PeriodicalId":167119,"journal":{"name":"2012 International Symposium on Wireless Communication Systems (ISWCS)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116701250","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}
{"title":"On network-coded rateless transmission: Protocol design, clustering and cooperator assignment","authors":"S. Maghsudi, S. Stańczak","doi":"10.1109/ISWCS.2012.6328379","DOIUrl":"https://doi.org/10.1109/ISWCS.2012.6328379","url":null,"abstract":"We propose a new transmission protocol for two-hop transmission employing rateless coding in the first hop and rateless-network coding in the second hop. In this protocol, communicating pairs (CP) and also relays are partitioned into small clusters; afterwards, each CP-cluster is assigned one relay cluster to improve data transmission. This scheme increases the diversity order (in comparison to the case where each CP exploits its own relay resources with no cooperation), without increasing the transmission cost (such as delay or energy), provided that the clustering-assignment form is optimized. We show that finding the optimal clustering-assignment (in the sense of cost minimization) boils down to the cascade of two graph-theoretic problems, namely graph partitioning and weighted matching, which can be solved efficiently. Moreover, we model the delay as cost, and analyze the expected transmission time. Numerical analysis demonstrates the effectiveness of our approach.","PeriodicalId":167119,"journal":{"name":"2012 International Symposium on Wireless Communication Systems (ISWCS)","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117238537","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}
{"title":"On the physical layer security of backscatter RFID systems","authors":"W. Saad, Zhu Han, H. Poor","doi":"10.1109/ISWCS.2012.6328537","DOIUrl":"https://doi.org/10.1109/ISWCS.2012.6328537","url":null,"abstract":"Securing radio frequency identification (RFID) systems against malicious attacks such as eavesdropping is a highly challenging task due to the resource constrained nature of such systems. In fact, the modest computational and storage capabilities of RFID tags makes it impossible to adopt classical cryptographic techniques. While existing work has mostly focused on lightweight cryptographic techniques, in this paper, the first analysis on the adoption of physical layer security techniques in an RFID system is presented. First, the secrecy rate of ultra high frequency (UHF) RFID backscatter systems is characterized. Then, a novel approach is proposed for maximizing this secrecy rate by exploiting the nature and features of the RFID backscatter channel. To explore these features, the proposed approach allows the RFID readers to append artificial noise signals to their continuous wave (CW) signals which then propagate via the backscatter channel hence inducing interference at the eavesdroppers. For enabling the readers to optimally allocate power between their CW signals and artificial noise, a noncooperative game is formulated using which the readers can decide on their optimal power allocations so as to maximize their overall secrecy rates, given the ensuing inter-reader interference. For solving this game, a best response algorithm is proposed using which the readers can reach a Nash equilibrium. Simulation results show that the proposed approach yields significant performance gains, in terms of the average secrecy rate per RFID reader, of at least 17% relative to the classical RFID operation.","PeriodicalId":167119,"journal":{"name":"2012 International Symposium on Wireless Communication Systems (ISWCS)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128103810","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}
{"title":"Reachability of the capacity in parallel quantised channels","authors":"C. Schmitz, A. Schmeink","doi":"10.1109/ISWCS.2012.6328466","DOIUrl":"https://doi.org/10.1109/ISWCS.2012.6328466","url":null,"abstract":"Based upon profound knowledge about wireless communication systems that was gathered during the past decades, modelling biological systems analogously has become more and more popular. Although the assumptions about the latter are sometimes less reliable than those about technical systems, some models have proven useful in explaining the behaviour of biological communication systems for example when affected by diseases like Alzheimer. In this work, such a model based upon parallel quantised channels is examined further. The key aspect is to figure out whether the proven capacity bounds are reachable, and under which conditions.","PeriodicalId":167119,"journal":{"name":"2012 International Symposium on Wireless Communication Systems (ISWCS)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128179198","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}
{"title":"Comparison of OFDM and FBMC performance in multi-relay cognitive radio network","authors":"M. Shaat, F. Bader","doi":"10.1109/ISWCS.2012.6328469","DOIUrl":"https://doi.org/10.1109/ISWCS.2012.6328469","url":null,"abstract":"A multicarrier based cognitive radio (CR) network is considered in this paper. The goal is to maximize the total sum rate of the CR system while ensuring that no excessive interference is induced to the primary system. The optimal scheme adopts the dual decomposition technique and in order to reduce the computational complexity of the optimal scheme, a greedy suboptimal algorithm is proposed. Selected numerical results is discussed to reveal the near-optimal performance of the suboptimal scheme and the superiority of the proposed algorithm over the random and the signal-to-noise ratio (SNR) based schemes. This paper highlights the advantages of using filter bank multicarrier (FBMC) instead of OFDM in the physical layer of the future CR systems.","PeriodicalId":167119,"journal":{"name":"2012 International Symposium on Wireless Communication Systems (ISWCS)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128407169","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}