Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850279
M. Ivrlac, J. Nossek
Both in the signal processing and in the information theory literature, it is common to assume that the array gain of antenna arrays grows linearly with the number of antennas. However, such an assertion is valid only when the antennas are uncoupled. When antenna coupling is present and properly taken into account by the signal processing algorithms, we show that both the transmit and the receive array gain can grow super-linearly with the number of antennas. In special cases, the receive array gain can even grow exponentially with the antenna number. These results are exciting, for they imply that the potential of radio communication systems which use more than one antenna at the receiver or the transmitter, is likely to be much higher than previously reported.
{"title":"Transmit and receive array gain of uniform linear arrays of isotrops","authors":"M. Ivrlac, J. Nossek","doi":"10.1109/SARNOF.2009.4850279","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850279","url":null,"abstract":"Both in the signal processing and in the information theory literature, it is common to assume that the array gain of antenna arrays grows linearly with the number of antennas. However, such an assertion is valid only when the antennas are uncoupled. When antenna coupling is present and properly taken into account by the signal processing algorithms, we show that both the transmit and the receive array gain can grow super-linearly with the number of antennas. In special cases, the receive array gain can even grow exponentially with the antenna number. These results are exciting, for they imply that the potential of radio communication systems which use more than one antenna at the receiver or the transmitter, is likely to be much higher than previously reported.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"93 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129419706","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}
Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850276
R. Marin-Lopez, Fernando Pereñíguez, Y. Ohba, Fernando Bernal, A. F. Gómez Skarmeta
In this paper we propose an architecture aimed for reducing the latency of network access authentication based on the Extensible Authentication Protocol (EAP). The architecture is based on the design of a new EAP method for which a standalone authenticator is used, and does not require any change to the EAP specification or the specifications of EAP lower-layers such as IEEE 802.11 and IEEE 802.16e. We also show
{"title":"A transport-based architecture for fast re-authentication in wireless networks","authors":"R. Marin-Lopez, Fernando Pereñíguez, Y. Ohba, Fernando Bernal, A. F. Gómez Skarmeta","doi":"10.1109/SARNOF.2009.4850276","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850276","url":null,"abstract":"In this paper we propose an architecture aimed for reducing the latency of network access authentication based on the Extensible Authentication Protocol (EAP). The architecture is based on the design of a new EAP method for which a standalone authenticator is used, and does not require any change to the EAP specification or the specifications of EAP lower-layers such as IEEE 802.11 and IEEE 802.16e. We also show","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123116207","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}
Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850353
L. Vangelista, M. Rotoloni
In this paper the second generation digital terrestrial distribution system standardized by the Digital Video Broadcasting Consortium (DVB-T2) is considered and, in particular, we focus on the new structure of the P1 training symbol. Two algorithms making use of this symbol are proposed and analyzed, one for the recovery of the carrier frequency offset, the other for the channel estimation. In particular, their performances are evaluated, theoretically and via simulations, and finally compared to the respective Cramer Rao Lower Bound (CRLB). The results show the two algorithms perform very close to the respective CRLB.
{"title":"On the analysis of P1 symbol performance for DVB-T2","authors":"L. Vangelista, M. Rotoloni","doi":"10.1109/SARNOF.2009.4850353","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850353","url":null,"abstract":"In this paper the second generation digital terrestrial distribution system standardized by the Digital Video Broadcasting Consortium (DVB-T2) is considered and, in particular, we focus on the new structure of the P1 training symbol. Two algorithms making use of this symbol are proposed and analyzed, one for the recovery of the carrier frequency offset, the other for the channel estimation. In particular, their performances are evaluated, theoretically and via simulations, and finally compared to the respective Cramer Rao Lower Bound (CRLB). The results show the two algorithms perform very close to the respective CRLB.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116764915","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}
Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850358
Y. Kondareddy, N. Andrews, P. Agrawal
Cognitive radio networks deal with opportunistic spectrum access leading to greater utilization of the spectrum. The extent of utilization depends on the primary user's traffic and also on the way the spectrum is accessed by the primary and secondary users. In this paper Continuous-time Markov chains are used to model the spectrum access. The proposed three-dimensional model represents a more accurate cognitive system than the existing models with increased spectrum utilization and than the random and reservation based spectrum access. A non-random access method is proposed to remove the forced termination states. In addition, call dropping and blocking probabilities are reduced. It is further shown that channel utilization is higher than random access and reservation based access.
{"title":"On the capacity of secondary users in a cognitive radio network","authors":"Y. Kondareddy, N. Andrews, P. Agrawal","doi":"10.1109/SARNOF.2009.4850358","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850358","url":null,"abstract":"Cognitive radio networks deal with opportunistic spectrum access leading to greater utilization of the spectrum. The extent of utilization depends on the primary user's traffic and also on the way the spectrum is accessed by the primary and secondary users. In this paper Continuous-time Markov chains are used to model the spectrum access. The proposed three-dimensional model represents a more accurate cognitive system than the existing models with increased spectrum utilization and than the random and reservation based spectrum access. A non-random access method is proposed to remove the forced termination states. In addition, call dropping and blocking probabilities are reduced. It is further shown that channel utilization is higher than random access and reservation based access.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125638985","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}
Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850315
D. Anurag, S. Bandyopadhyay
Most wireless sensor network deployments are 2-tiered where sensors form the leaves of the network and do not participate in the routing. A plot of the best path from each of the leaves to the sink reveals the network topology to be hierarchical in nature. The AODV routing algorithm was designed for a mesh network with highly mobile nodes and is not directly suitable for a hierarchical sensor network where the sensors and relays are predominantly static. The hierarchical routing as implemented by ZigBee's Cskip does not support fault tolerance and has a restriction on the network depth. In this paper, we develop a node addressing methodology that merges the structure of a hierarchical tree with the flexibility of AODV. We show its completeness and develop three algorithms - deterministic, probabilistic and heuristic, based on our methodology. The performance of the algorithms against AODV is compared. Our simulation is made for two probability distributions of network formation — uniform and geometric.
{"title":"Node addressing schemes for scalable and fault tolerant routing in hierarchical WSNs","authors":"D. Anurag, S. Bandyopadhyay","doi":"10.1109/SARNOF.2009.4850315","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850315","url":null,"abstract":"Most wireless sensor network deployments are 2-tiered where sensors form the leaves of the network and do not participate in the routing. A plot of the best path from each of the leaves to the sink reveals the network topology to be hierarchical in nature. The AODV routing algorithm was designed for a mesh network with highly mobile nodes and is not directly suitable for a hierarchical sensor network where the sensors and relays are predominantly static. The hierarchical routing as implemented by ZigBee's Cskip does not support fault tolerance and has a restriction on the network depth. In this paper, we develop a node addressing methodology that merges the structure of a hierarchical tree with the flexibility of AODV. We show its completeness and develop three algorithms - deterministic, probabilistic and heuristic, based on our methodology. The performance of the algorithms against AODV is compared. Our simulation is made for two probability distributions of network formation — uniform and geometric.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127793632","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}
Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850376
J. Yao
Broadband and low loss capability of photonics has led to an ever-increasing interest in its use for the processing of microwave and millimeter-wave signals. In this paper, microwave delay-line filters implemented using photonics techniques are reviewed, with an emphasis on the implementation of microwave delay-line filters with bandpass functionality.
{"title":"Photonics for microwave signal filtering","authors":"J. Yao","doi":"10.1109/SARNOF.2009.4850376","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850376","url":null,"abstract":"Broadband and low loss capability of photonics has led to an ever-increasing interest in its use for the processing of microwave and millimeter-wave signals. In this paper, microwave delay-line filters implemented using photonics techniques are reviewed, with an emphasis on the implementation of microwave delay-line filters with bandpass functionality.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132801961","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}
Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850272
U. Rohde, A. Poddar
The novel approach reported in this paper optimizes the dynamic noise and drive sensitivity factor for achieving low phase noise voltage controlled crystal oscillator circuit (VCXO). An example of 100 MHz mode feedbacks and differential coupled VCXOs are demonstrated for the validation of this new approach, which offers 10–15 dB phase noise reduction, therefore, spectral pure, power-efficient and cost-effective solutions.
{"title":"Voltage controlled crystal oscillator","authors":"U. Rohde, A. Poddar","doi":"10.1109/SARNOF.2009.4850272","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850272","url":null,"abstract":"The novel approach reported in this paper optimizes the dynamic noise and drive sensitivity factor for achieving low phase noise voltage controlled crystal oscillator circuit (VCXO). An example of 100 MHz mode feedbacks and differential coupled VCXOs are demonstrated for the validation of this new approach, which offers 10–15 dB phase noise reduction, therefore, spectral pure, power-efficient and cost-effective solutions.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134408954","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}
Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850348
Yi Xie, Xiapu Luo, R. Chang
Energy management in a wireless LAN is an important problem, as the viability of wireless devices depends very much on their battery life. In this paper, we propose a centralized power saving mode (C-PSM), an AP-centric PSM for 802.11 infrastructure networks. Having the AP select optimal PSM parameters, such as the beacon and listen intervals, CPSM is able to maximize the total energy efficiency for all clients. Moreover, C-PSM provides a first-wake-up schedule to further increase the energy efficiency by reducing clients' simultaneous wake-ups. Extensive simulation experiments show that C-PSM outperforms the standard PSM by a very significant margin. In our set of experiments, C-PSM reduces power consumption and increases energy efficiency by as much as 76% and 320%, respectively. As a side benefit, C-PSM also decreases the frame buffering delay at the AP by 88%. The wake-up schedule can save clients' energy consumption by 22% at most. Moreover, the improvement increases with the number of clients.
{"title":"Centralized PSM: An AP-centric power saving Mode for 802.11 infrastructure networks","authors":"Yi Xie, Xiapu Luo, R. Chang","doi":"10.1109/SARNOF.2009.4850348","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850348","url":null,"abstract":"Energy management in a wireless LAN is an important problem, as the viability of wireless devices depends very much on their battery life. In this paper, we propose a centralized power saving mode (C-PSM), an AP-centric PSM for 802.11 infrastructure networks. Having the AP select optimal PSM parameters, such as the beacon and listen intervals, CPSM is able to maximize the total energy efficiency for all clients. Moreover, C-PSM provides a first-wake-up schedule to further increase the energy efficiency by reducing clients' simultaneous wake-ups. Extensive simulation experiments show that C-PSM outperforms the standard PSM by a very significant margin. In our set of experiments, C-PSM reduces power consumption and increases energy efficiency by as much as 76% and 320%, respectively. As a side benefit, C-PSM also decreases the frame buffering delay at the AP by 88%. The wake-up schedule can save clients' energy consumption by 22% at most. Moreover, the improvement increases with the number of clients.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125517733","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}
Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850304
S. Kulkarni, P. S. Prasad, P. Agrawal
Spatial diversity achieved via nodal cooperation is known to alleviate the ill effects of channel fading in wireless networks. But to exploit this phenomenon the idea of node cooperation needs to be extended to other layers of the protocol stack, especially the MAC layer. This paper takes a close look at Synergy MAC, a cooperative MAC protocol, proposed for wireless mobile ad hoc networks. The studied protocol also leverages on the multi-rate capability of 802.11b to allow nodes with low SNR to their destination make use of intermediate relays, to transmit data at rates higher than otherwise possible. The performance improvement achieved by this protocol in comparison to 802.11b is then evaluated through extensive simulations.
{"title":"Enabling cooperation in mobile ad hoc networks","authors":"S. Kulkarni, P. S. Prasad, P. Agrawal","doi":"10.1109/SARNOF.2009.4850304","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850304","url":null,"abstract":"Spatial diversity achieved via nodal cooperation is known to alleviate the ill effects of channel fading in wireless networks. But to exploit this phenomenon the idea of node cooperation needs to be extended to other layers of the protocol stack, especially the MAC layer. This paper takes a close look at Synergy MAC, a cooperative MAC protocol, proposed for wireless mobile ad hoc networks. The studied protocol also leverages on the multi-rate capability of 802.11b to allow nodes with low SNR to their destination make use of intermediate relays, to transmit data at rates higher than otherwise possible. The performance improvement achieved by this protocol in comparison to 802.11b is then evaluated through extensive simulations.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125505007","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}
Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850317
E. Oki, A. Iwaki
This paper compares performances of optimal routing by the pipe, hose, and intermediate models. The pipe model, which is specified by the exact traffic matrix, provides the best routing performance, while the traffic matrix is difficult to measure and predict accurately. On the other hand, the hose model is specified by the traffic as just the total outgoing/incoming traffic from/to each node, but it has a problem that its routing performance is degraded compared to the pipe model, due to insufficient traffic information. The intermediate model, where the upper and lower bounds of traffic demands for source-destination pairs are added as constraints, is a construction that lies between the pipe and hose models. The intermediate model, which lightens the difficulty of the pipe model, but narrows the range of traffic conditions specified by the hose model, enhances the routing performance compared to the hose model. An optimal-routing formulation extended from the pipe model to the intermediate model can not be solved as a regular linear programming (LP) problem. Our solution, the introduction of a duality theorem, turns our problem into an LP formulation that can be easily solved. Numerical results show that the network congestion ratio for the pipe model is much lower than that of hose model. The differences of network congestion ratios between the pipe and hose models lie in the range from 27% to 45% for the various examined network topologies. The intermediate model offers better routing performance than the hose model. The reduction effect of the network congestion ratio by the intermediate model is 26% compared to the hose model, when the upper-bound margin is set 25%.
{"title":"Performance comparisons of optimal routing by pipe, hose, and intermediate models","authors":"E. Oki, A. Iwaki","doi":"10.1109/SARNOF.2009.4850317","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850317","url":null,"abstract":"This paper compares performances of optimal routing by the pipe, hose, and intermediate models. The pipe model, which is specified by the exact traffic matrix, provides the best routing performance, while the traffic matrix is difficult to measure and predict accurately. On the other hand, the hose model is specified by the traffic as just the total outgoing/incoming traffic from/to each node, but it has a problem that its routing performance is degraded compared to the pipe model, due to insufficient traffic information. The intermediate model, where the upper and lower bounds of traffic demands for source-destination pairs are added as constraints, is a construction that lies between the pipe and hose models. The intermediate model, which lightens the difficulty of the pipe model, but narrows the range of traffic conditions specified by the hose model, enhances the routing performance compared to the hose model. An optimal-routing formulation extended from the pipe model to the intermediate model can not be solved as a regular linear programming (LP) problem. Our solution, the introduction of a duality theorem, turns our problem into an LP formulation that can be easily solved. Numerical results show that the network congestion ratio for the pipe model is much lower than that of hose model. The differences of network congestion ratios between the pipe and hose models lie in the range from 27% to 45% for the various examined network topologies. The intermediate model offers better routing performance than the hose model. The reduction effect of the network congestion ratio by the intermediate model is 26% compared to the hose model, when the upper-bound margin is set 25%.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117337705","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}
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