2012 IEEE International Symposium on Dynamic Spectrum Access Networks最新文献

{"title":"Efficient sidelobe suppression for OFDM systems with peak-to-average power ratio reduction","authors":"Ahmed A. S. Seleim, Baris Özgül, L. Doyle","doi":"10.1109/DYSPAN.2012.6478175","DOIUrl":"https://doi.org/10.1109/DYSPAN.2012.6478175","url":null,"abstract":"This paper describes a practical method for sidelobe suppression for orthogonal frequency-division multiplexing (OFDM) signals. Most of the existing sidelobe suppression techniques are computationally expensive. The proposed technique is simpler in terms of computational complexity, and it enables high suppression capability. In addition, most of the related work deals with either sidelobe suppression or peak-to-average power ratio (PAPR) reduction which are mutually exclusive in some cases. However, the proposed technique is compatible with some PAPR reduction techniques. Simulation results show that the proposed technique can achieve significant sidelobe suppression. In addition, under adjacent channel interference constraints, the proposed algorithm outperforms the conventional OFDM transmissions in terms of bit-error rate (BER). Moreover, the proposed algorithm is implemented on a software defined radio and tested for practical and real-time transmissions.","PeriodicalId":224818,"journal":{"name":"2012 IEEE International Symposium on Dynamic Spectrum Access Networks","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127448765","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":"A multitaper hardware core for spectrum sensing","authors":"S. Kyperountas, Qicai Shi, A. Vallejo, N. Correal","doi":"10.1109/DYSPAN.2012.6478114","DOIUrl":"https://doi.org/10.1109/DYSPAN.2012.6478114","url":null,"abstract":"We have implemented a non-iterative multitaper sensing hardware core. The multitaper core computes the spectrum as the average of M eigenspectra calculated using Slepian sequences. While more computationally complex than traditional Fourier methods, the multitaper estimation method offers enhanced performance. The working multitaper hardware core was validated on FPGA using over the air RF measurements in the UHF T-Band. The multitaper core has been incorporated into a prototype frequency agile spectrum sensing platform.","PeriodicalId":224818,"journal":{"name":"2012 IEEE International Symposium on Dynamic Spectrum Access Networks","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128873110","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":"Pluralistic licensing","authors":"O. Holland, L. D. Nardis, K. Nolan, A. Medeisis, P. Anker, L. Minervini, F. Velez, M. Matinmikko, J. Sydor","doi":"10.1109/DYSPAN.2012.6478113","DOIUrl":"https://doi.org/10.1109/DYSPAN.2012.6478113","url":null,"abstract":"We introduce the concept of “pluralistic licensing”, which we describe as the award of licenses under the assumption that opportunistic secondary spectrum access will be allowed, and that interference may be caused to the primary with parameters and rules that are known to the primary at the point of obtaining the license. A key aspect of the concept is that the primary will choose from a range of offered “pluralistic licenses” each with associated fees, and each specifying alternative opportunistic access rules and associated interference characteristics. Our proposal is a novel means to take forward spectrum licensing which is fair to both primary and secondary users and takes into account the requirements of both parties. The objective is to incentivize the primary to obtain this type of license through means such as a reduced license fee, whereby the opportunistic secondary spectrum access will use “cognitive radio” mechanisms to avoid causing interference to the primary or to otherwise keep interference within known parameters. We discuss that our proposed concept can propel more robust or better design of both primary and secondary devices. For primary devices it can lead to the ability to cope with an increased degree or risk of interference among other benefits, and for secondary devices might lead to the ability to better share spectrum opportunities. Both of these aspects greatly improve spectrum usage efficiency and fairness. Our concept is also highly flexible dependent on the case-by-case deployment context, even so far as allowing solutions such as spectrum sensing and primary beacon transmissions which would otherwise not be practical or desirable, while defaulting to safe mechanisms such as a geolocation database in cases where a lower interference variance is required. Many other benefits of our concept and its extensions are discussed. We argue that “pluralistic licensing” should become the de facto form of license awarded in newly designated bands, and should also be offered to the primary as a licensing option in existing bands in cases where interference to legacy devices that might exist in the band can be avoided.","PeriodicalId":224818,"journal":{"name":"2012 IEEE International Symposium on Dynamic Spectrum Access Networks","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132806258","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":"Measurement-calibrated conflict graphs for dynamic spectrum distribution","authors":"Xia Zhou, Zengbin Zhang, G. Wang, Xiaoxiao Yu, Ben Y. Zhao, Haitao Zheng","doi":"10.1109/DYSPAN.2012.6478150","DOIUrl":"https://doi.org/10.1109/DYSPAN.2012.6478150","url":null,"abstract":"Building accurate interference maps is critical for performing reliable and efficient spectrum allocation. In this work, we use empirical data to explore the feasibility of using measurement-calibrated propagation models to build accurate interference models. Our work shows that calibrated propagation models generate location-dependent signal prediction errors. Such error pattern leads to conservative conflict graphs that actually improve the reliability of spectrum allocations by reducing the impact of unpredicted accumulative interference.","PeriodicalId":224818,"journal":{"name":"2012 IEEE International Symposium on Dynamic Spectrum Access Networks","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133253002","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 time-domain coexistence of unlicensed and licensed spectrum users","authors":"Ashwini Kumar, K. Shin, Young-June Choi, D. Niculescu","doi":"10.1109/DYSPAN.2012.6478133","DOIUrl":"https://doi.org/10.1109/DYSPAN.2012.6478133","url":null,"abstract":"This paper aims to exploit spectrum white spaces in time-domain via the Dynamic Spectrum Access (DSA) technology. DSA relies on opportunistic access of licensed spectrum by unlicensed devices. Any “unlicensed-with-licensed” coexistence must ensure “safe” (i.e., un-interfered) communications for the incumbents, while achieving high spectrum-use efficiency for the secondary users. We propose a novel and comprehensive metric called the Coexistence Goodness Factor (CGF) to accurately model the inherent tradeoff between incumbent safety and unlicensed access efficiency for time-domain DSA-based coexistence. To optimize the coexistence performance, we propose a generic, online, dual-mode DSA coexistence protocol. The unlicensed devices attempt to estimate incumbent behavior patterns, and enter the Aggressive Mode (AM) once such a pattern is found, while they stay in the Safe Mode (SM) otherwise. For low-overhead and reliable estimation of incumbent spectrum-usage patterns, we propose algorithms based on Approximate Entropy (ApEn). Further, we design Spectrum-Conscious WiFi (SpeCWiFi), which provisions the proposed DSA coexistence scheme to the base 802.11 MAC. We conduct an extensive experimental evaluation of SpeCWiFi using a MadWifi-based prototype implementation in conjunction with 802.11 wireless cards. The evaluation shows that SpeCWiFi achieves excellent time-domain DSA coexistence in the presence of different types of licensed spectrum, including fast-varying channels that feature short-duration white spaces.","PeriodicalId":224818,"journal":{"name":"2012 IEEE International Symposium on Dynamic Spectrum Access Networks","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114233297","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":"Secondary spectrum access in TV-bands with combined co-channel and adjacent channel interference constraints","authors":"Lei Shi, K. Sung, J. Zander","doi":"10.1109/DYSPAN.2012.6478169","DOIUrl":"https://doi.org/10.1109/DYSPAN.2012.6478169","url":null,"abstract":"The potential of VHF/UHF band as a candidate for secondary spectrum access, so called “TV white spaces”, has been intensively investigated in recent years. However, the impact of the accumulated interference from multiple secondary users on different adjacent channels has not been well studied thus far, let alone the effect of combined interference from both co-channel and adjacent channels. This paper presents a framework for assessing secondary spectrum reuse opportunities for portable and mobile devices that comply with geo-location database concepts. The opportunity is evaluated in terms of the maximal number of secondary users that can access the “TV white space” simultaneously. Particular emphasis is given to the protection of TV receiver from harmful aggregate interference originated from not only the secondary users outside the TV coverage on the same channel but also those close to the TV receivers operating on different adjacent TV channels. An optimization problem is solved to maximize the number of secondary users admitted to the available TV channels at different locations. Through in-depth analysis of the interference characteristics of the optimal solution, it is identified that the cumulative effect of adjacent channel interferences has the dominant impact on TV reception, particularly for the case of secondary devices with limited transmit power. This suggests the possibility to achieve near-optimal exploitation of TV-bands for secondary reuse without explicit coordination of co-channel interference from the secondary users deployed over a wide geographical area.","PeriodicalId":224818,"journal":{"name":"2012 IEEE International Symposium on Dynamic Spectrum Access Networks","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116963583","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":"To subscribe, or not to subscribe: Modeling and analysis of service paradigms in cellular markets","authors":"Georgios Fortetsanakis, M. Papadopouli, G. Karlsson, Manos Dramitinos, Emre A. Yavuz","doi":"10.1109/DYSPAN.2012.6478130","DOIUrl":"https://doi.org/10.1109/DYSPAN.2012.6478130","url":null,"abstract":"Traditionally customers subscribe to specific providers and are served by accessing base stations (BSs) of the network of their provider. Inevitably subscribers with relatively “high” usage pattern and data-rate requirements are subsidized by the ones with lower usage and data-rates. As the wireless technology advances, a diverse set of services will be available. This paper introduces the “flex service” paradigm that allows a customer to dynamically access BSs of different providers based on various criteria, such as profile, network conditions, and offered prices. “Flex users” can select the appropriate provider and BS on a per-session basis. This work considers a diverse customer population with respect to their demand, their preference on data-rate over price, their tolerance on the blocking probabilities of their sessions, and their willingness to pay for certain services. Users can dynamically decide to buy a long-term subscription or become flex users. In this paper, we develop a rich framework for modeling and analysis of such markets in different spatio-temporal scales. We analyze the evolution of markets with the flex service paradigm, focusing on whether it can improve the quality-of-service (QoS), social welfare, flexibility and further enhance the competition among providers. The main contribution of this paper is detailed modeling and indepth performance analysis of such complex markets, in different spatial and temporal scales. It considers the perspective of clients, providers, and regulators. It demonstrates the benefits of markets with the flex service paradigm and compares them with the ones that only offer subscription contracts.","PeriodicalId":224818,"journal":{"name":"2012 IEEE International Symposium on Dynamic Spectrum Access Networks","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123682668","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":"Overlay spectrum reuse in a broadcast network: Covering the whole grayscale of spaces","authors":"Alberto Rico-Alvariño, C. Mosquera","doi":"10.1109/DYSPAN.2012.6478172","DOIUrl":"https://doi.org/10.1109/DYSPAN.2012.6478172","url":null,"abstract":"In this paper we address the problem of allowing secondary access to the spectrum assigned to a broadcast operator. We assume that the secondary transmitter knows of the primary message but is not able to apply interference cancellation techniques due to the lack of channel state information. Thus, interference cancellation can only be performed at the secondary receivers, provided they are able to decode the primary message. Unlike previous approaches, which study the particular cases of secondary access in a white space (far away from the influence of the primary transmitter) or a black space (inside the primary coverage zone), we present an analysis which is valid for any position of the secondary operation area. An interesting result arises from the study of gray spaces (a region which is near the primary coverage area), where the optimum power allocation for the secondary transmitter can increment the primary coverage area, thus benefiting the primary system.","PeriodicalId":224818,"journal":{"name":"2012 IEEE International Symposium on Dynamic Spectrum Access Networks","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128425675","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":"Ontology-based spectrum access policies for policy-based cognitive radios","authors":"B. Bahrak, J. Park, Hao Wu","doi":"10.1109/DYSPAN.2012.6478173","DOIUrl":"https://doi.org/10.1109/DYSPAN.2012.6478173","url":null,"abstract":"To maximize their efficacy, cognitive radios (CRs) need to be able to cope with the constantly changing spectrum environment, evolving spectrum access policies, and a diverse array of network application requirements. Policy-based cognitive radios address these challenges by decoupling the spectrum access policies from device-specific implementations and optimizations. These radios can invoke situation-appropriate, adaptive actions based on policy specifications and the current spectrum environment. A policy-based CR has a reasoning engine called a policy reasoner. The primary task carried out by the policy reasoner is evaluating the transmission requests with respect to the spectrum policies. In this paper, we describe the design of a policy reasoner that processes ontology-based spectrum policies. The main advantage of using ontology-based policies is that the policy reasoner can understand and process any spectrum policies authored by any organization by relying on the spectrum ontologies. In our implementation, the spectrum ontology defines the various dynamic spectrum access (DSA) concepts, models the domain of DSA networks in a machine-understandable manner, and uses SWRL (Semantic Web Rule Language) rules to represent spectrum policies. Unfortunately, ontological reasoning needed to process ontology-based spectrum policies incurs greater computation overhead compared to non-ontological reasoning. This drawback can be a critical one as it can impede a CR from meeting its real-time performance requirements. We have carried out a number of experiments, using our implementation, to evaluate whether a radio controlled by ontology-based policies can meet its real-time performance requirements. Based on our experimental results, we propose a set of guidelines for the design of ontology-based spectrum access policies.","PeriodicalId":224818,"journal":{"name":"2012 IEEE International Symposium on Dynamic Spectrum Access Networks","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121847540","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":"Channel sensing order in multi-user cognitive radio networks","authors":"Jie Zhao, Xin Wang","doi":"10.1109/DYSPAN.2012.6478163","DOIUrl":"https://doi.org/10.1109/DYSPAN.2012.6478163","url":null,"abstract":"This paper investigates the sensing order problem for multi-user and multi-channel cognitive radio networks. While most of the literature studies focus on the sensing order for a single user, we consider the scenario in which multiple secondary users sequentially sense and access the channel according to their individual sensing orders. In multi-user case, channel access collisions among secondary users will lead to performance degradation. We propose a novel metric that comprehensively consider the channel availability, transmission rate and collision probability, and exploit an efficient dynamic programming algorithm to establish the sensing order based on the metric to improve the sensing efficiency and transmission throughput. Simulation results demonstrate that our algorithm can not only effectively reduce the collisions among secondary users, but also can achieve higher network throughput than other schemes studied. Furthermore, we also discuss how the network environment impacts the performances of different sensing orders.","PeriodicalId":224818,"journal":{"name":"2012 IEEE International Symposium on Dynamic Spectrum Access Networks","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123086549","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}