Pub Date : 2011-04-19DOI: 10.1109/RADIOELEK.2011.5936404
S. Pollak, V. Wieser
Wireless mesh networks (WMNs) offer many advantages in terms of reliability, scalability and connectivity. These networks provide multiple paths between nodes. Traditionally, WMNs used nodes equipped with a single radio interface. In single radio WMNs exist many limitations, such as lower throughput and limited usage of the available wireless channels. In this paper, we present the effect of the number of interfaces increasing on WMN capacity. The WMN simulation model was created, where the optimal number of interfaces for WMNs was determined to improve chosen quality of service (QoS) parameters in service with constant bit rate (CBR) requirements.
{"title":"Optimal number of radio interfaces in wireless mesh network","authors":"S. Pollak, V. Wieser","doi":"10.1109/RADIOELEK.2011.5936404","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2011.5936404","url":null,"abstract":"Wireless mesh networks (WMNs) offer many advantages in terms of reliability, scalability and connectivity. These networks provide multiple paths between nodes. Traditionally, WMNs used nodes equipped with a single radio interface. In single radio WMNs exist many limitations, such as lower throughput and limited usage of the available wireless channels. In this paper, we present the effect of the number of interfaces increasing on WMN capacity. The WMN simulation model was created, where the optimal number of interfaces for WMNs was determined to improve chosen quality of service (QoS) parameters in service with constant bit rate (CBR) requirements.","PeriodicalId":267447,"journal":{"name":"Proceedings of 21st International Conference Radioelektronika 2011","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129934107","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 : 2011-04-19DOI: 10.1109/RADIOELEK.2011.5936464
P. Piksa
This paper is focused on comparison of two types of conical corrugated horn antennas. First antenna has a design with a simple structure which was optimized to reach minimum level of side-lobes and maximum of gain. Second antenna is a typical corrugated horn made from complex theoretical design with a complicated structure. The second antenna has minimal cross-polarization achieved by a balanced hybrid conditions between HE1n modes accomplished by a special distribution of depth of the slots. The second antenna consists of a conical horn with the corrugated surface and a mode converter which transforms TE11 to HE11 mode. The mode converter is omitted in the first antenna.
{"title":"Comparison of conical horn with optimized corrugated surface and corrugated horn","authors":"P. Piksa","doi":"10.1109/RADIOELEK.2011.5936464","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2011.5936464","url":null,"abstract":"This paper is focused on comparison of two types of conical corrugated horn antennas. First antenna has a design with a simple structure which was optimized to reach minimum level of side-lobes and maximum of gain. Second antenna is a typical corrugated horn made from complex theoretical design with a complicated structure. The second antenna has minimal cross-polarization achieved by a balanced hybrid conditions between HE1n modes accomplished by a special distribution of depth of the slots. The second antenna consists of a conical horn with the corrugated surface and a mode converter which transforms TE11 to HE11 mode. The mode converter is omitted in the first antenna.","PeriodicalId":267447,"journal":{"name":"Proceedings of 21st International Conference Radioelektronika 2011","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132159346","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 : 2011-04-19DOI: 10.1109/RADIOELEK.2011.5936456
Jan Benes, J. Prokopec
Mobile WiMAX (Worldwide Interoperability for Microwave Access) standardized by IEEE 802.16e is a broadband wireless system based on Scalable OFDMA (Orthogonal Frequency Division Multiple Access). This standard is suitable for the last mile connection in areas where it is not possible to build wired infrastructure, nevertheless it provides a broadband connection for nomadic users and supports cellular structure. Its main advantage compared to Wi-Fi standard is the possibility of a very powerful handling of radio resources allocation to users in order to adjust quality of radio-environment and number of active users at given area. This article investigates impact of different encoding schemes used in Mobile WiMAX to theoretical throughput and deals with efficiency evaluation of these schemes.
{"title":"Efficiency of encoding schemes in mobile WiMAX","authors":"Jan Benes, J. Prokopec","doi":"10.1109/RADIOELEK.2011.5936456","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2011.5936456","url":null,"abstract":"Mobile WiMAX (Worldwide Interoperability for Microwave Access) standardized by IEEE 802.16e is a broadband wireless system based on Scalable OFDMA (Orthogonal Frequency Division Multiple Access). This standard is suitable for the last mile connection in areas where it is not possible to build wired infrastructure, nevertheless it provides a broadband connection for nomadic users and supports cellular structure. Its main advantage compared to Wi-Fi standard is the possibility of a very powerful handling of radio resources allocation to users in order to adjust quality of radio-environment and number of active users at given area. This article investigates impact of different encoding schemes used in Mobile WiMAX to theoretical throughput and deals with efficiency evaluation of these schemes.","PeriodicalId":267447,"journal":{"name":"Proceedings of 21st International Conference Radioelektronika 2011","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131351932","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 : 2011-04-19DOI: 10.1109/RADIOELEK.2011.5936480
O. Kaller, T. Kratochvil
This paper briefly summaries relation of camera configuration and extended stereo baseline to distortions that can be caused by camera shooting. The reasons, why to use these are also mentioned in the paper. Influence of nontraditional configuration of the cameras on the depth map generation of the 3D video content has been practically described and measured. Depth map dynamic range compression and utilization has been estimated too. It is also mentioned in the paper how to reduce Cardboard Distortion typical in 3D video.
{"title":"Hyper stereo base cameras setting for widescreen long distance target shooting application","authors":"O. Kaller, T. Kratochvil","doi":"10.1109/RADIOELEK.2011.5936480","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2011.5936480","url":null,"abstract":"This paper briefly summaries relation of camera configuration and extended stereo baseline to distortions that can be caused by camera shooting. The reasons, why to use these are also mentioned in the paper. Influence of nontraditional configuration of the cameras on the depth map generation of the 3D video content has been practically described and measured. Depth map dynamic range compression and utilization has been estimated too. It is also mentioned in the paper how to reduce Cardboard Distortion typical in 3D video.","PeriodicalId":267447,"journal":{"name":"Proceedings of 21st International Conference Radioelektronika 2011","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122216514","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 : 2011-04-19DOI: 10.1109/RADIOELEK.2011.5936388
A. Chapari, Z. Firouzeh, R. Moini, S. Sadeghi
This paper presents the effects of a small satellite structure on the characteristics of Quadrifilar Helical Antennas (QHAs). The antenna is first analyzed in free space in order to achieve the desired radiation pattern using Method of Moment (MoM). Two antennas are then simulated in the presence of the satellite structure for two different distances from the satellite surface. It is shown that performance of the antenna is remarkably affected by the satellite structure. Having obtained the radiation pattern of the antenna in the vicinity of the satellite structure, one can use the antenna with the more desirable feature to be implemented.
{"title":"Effects of the LEO satellite structure on the performance of Quadrifilar Helical Antennas","authors":"A. Chapari, Z. Firouzeh, R. Moini, S. Sadeghi","doi":"10.1109/RADIOELEK.2011.5936388","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2011.5936388","url":null,"abstract":"This paper presents the effects of a small satellite structure on the characteristics of Quadrifilar Helical Antennas (QHAs). The antenna is first analyzed in free space in order to achieve the desired radiation pattern using Method of Moment (MoM). Two antennas are then simulated in the presence of the satellite structure for two different distances from the satellite surface. It is shown that performance of the antenna is remarkably affected by the satellite structure. Having obtained the radiation pattern of the antenna in the vicinity of the satellite structure, one can use the antenna with the more desirable feature to be implemented.","PeriodicalId":267447,"journal":{"name":"Proceedings of 21st International Conference Radioelektronika 2011","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126041514","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 : 2011-04-19DOI: 10.1109/RADIOELEK.2011.5936397
R. Sotner, J. Frydrych, J. Slezák, T. Dostál, Milos Basta
A quite simple adjustable oscillator based on adjustable selective section and lossless integrator is presented in this paper. First order selective section is based on current mode adjustable attenuators employing current-mode multipliers. Characteristic equation, features of electronic adjusting, sensitivities, distortion of output signal and influences of parasitic elements are discussed. Theoretical and estimated assumptions are supported by simulation and experimental results.
{"title":"Voltage controlled oscillator using adjustable current-mode selective section with current attenuators","authors":"R. Sotner, J. Frydrych, J. Slezák, T. Dostál, Milos Basta","doi":"10.1109/RADIOELEK.2011.5936397","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2011.5936397","url":null,"abstract":"A quite simple adjustable oscillator based on adjustable selective section and lossless integrator is presented in this paper. First order selective section is based on current mode adjustable attenuators employing current-mode multipliers. Characteristic equation, features of electronic adjusting, sensitivities, distortion of output signal and influences of parasitic elements are discussed. Theoretical and estimated assumptions are supported by simulation and experimental results.","PeriodicalId":267447,"journal":{"name":"Proceedings of 21st International Conference Radioelektronika 2011","volume":"48 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114039908","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 : 2011-04-19DOI: 10.1109/RADIOELEK.2011.5936403
F. Khateb, N. Khatib
Bulk-driven technique has been verified to be a promising candidate in the area of low-voltage low-power techniques. In this paper, class AB current conveyor utilizing bulk-driven technique has been proposed. The proposed circuit was implemented based on CMOS technology to put a step forward in the field of low-voltage low-power applications; the non-ideal model of current conveyor has been explained. The circuit has been simulated at ±0.4 V supply voltage and total power dissipation 27.8 μW. The simulation results have been included to prove the theoretical consideration.
{"title":"New bulk-driven class AB CCII","authors":"F. Khateb, N. Khatib","doi":"10.1109/RADIOELEK.2011.5936403","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2011.5936403","url":null,"abstract":"Bulk-driven technique has been verified to be a promising candidate in the area of low-voltage low-power techniques. In this paper, class AB current conveyor utilizing bulk-driven technique has been proposed. The proposed circuit was implemented based on CMOS technology to put a step forward in the field of low-voltage low-power applications; the non-ideal model of current conveyor has been explained. The circuit has been simulated at ±0.4 V supply voltage and total power dissipation 27.8 μW. The simulation results have been included to prove the theoretical consideration.","PeriodicalId":267447,"journal":{"name":"Proceedings of 21st International Conference Radioelektronika 2011","volume":"2018 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133459670","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 : 2011-04-19DOI: 10.1109/RADIOELEK.2011.5936437
Frank Schumacher, Markus Holzer, Thomas Greiner, W. Rosenstiel
While most current graphical modeling languages for specifying digital signal processing algorithms provide a rich set of loop techniques and execution semantics based on IP-libraries, they lack in general of the flexibility of model based development frameworks. Also, the potential of recursive and repetitive graphical descriptions is mostly not utilized. We present a novel graphical notation to describe digital signal processing systems which enables the general specification of repetitive and recursive algorithms with hierarchical and parallel behavior diagrams. Our approach closes also the gap to flexible model-driven approaches by using extended UML Activity Diagrams, which enable the use of model based techniques including abstract descriptions, model-to-model-transformations and code generation for rapid prototyping of hardware and software systems.
{"title":"Modeling and code generation of recursive algorithms with extended UML Activity Diagrams","authors":"Frank Schumacher, Markus Holzer, Thomas Greiner, W. Rosenstiel","doi":"10.1109/RADIOELEK.2011.5936437","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2011.5936437","url":null,"abstract":"While most current graphical modeling languages for specifying digital signal processing algorithms provide a rich set of loop techniques and execution semantics based on IP-libraries, they lack in general of the flexibility of model based development frameworks. Also, the potential of recursive and repetitive graphical descriptions is mostly not utilized. We present a novel graphical notation to describe digital signal processing systems which enables the general specification of repetitive and recursive algorithms with hierarchical and parallel behavior diagrams. Our approach closes also the gap to flexible model-driven approaches by using extended UML Activity Diagrams, which enable the use of model based techniques including abstract descriptions, model-to-model-transformations and code generation for rapid prototyping of hardware and software systems.","PeriodicalId":267447,"journal":{"name":"Proceedings of 21st International Conference Radioelektronika 2011","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115627142","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 : 2011-04-19DOI: 10.1109/RADIOELEK.2011.5936481
P. Kučera, F. Mohr
This contribution deals with a polariscope, an instrument for determining internal strain in a transparent medium by exploiting its polarization transmission: When a sample of birefringent material is inserted in a polarized beam of light a fringe pattern is observed. The pattern is captured by a camera and processed to reveal internal stresses in the probe. However, in order to completely specify stresses, four patterns obtained under different optical conditions are used. These can be achieved either by using a rotating analyzer in the optical setup or by applying the so called “Multispec Imager” approach where the output beam is divided into several parallel beams which can then be directed to separate sections of a single camera or to several individual cameras. Disadvantages of the former solution is the requirement of a mechanically rotated component (necessitating a driving motor and longer measurement time whence this concept is far from being suitable for real-time use) and of the latter is its price and higher complexity of the optical layout. The use of micropolarizers in a digital polariscope removes all stated disadvantages, hence such a polariscope processes a single beam (no need of beam-splitting) and one fringe pattern (no need of a rotating analyzer).
{"title":"Micropolarizers in real time polariscope","authors":"P. Kučera, F. Mohr","doi":"10.1109/RADIOELEK.2011.5936481","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2011.5936481","url":null,"abstract":"This contribution deals with a polariscope, an instrument for determining internal strain in a transparent medium by exploiting its polarization transmission: When a sample of birefringent material is inserted in a polarized beam of light a fringe pattern is observed. The pattern is captured by a camera and processed to reveal internal stresses in the probe. However, in order to completely specify stresses, four patterns obtained under different optical conditions are used. These can be achieved either by using a rotating analyzer in the optical setup or by applying the so called “Multispec Imager” approach where the output beam is divided into several parallel beams which can then be directed to separate sections of a single camera or to several individual cameras. Disadvantages of the former solution is the requirement of a mechanically rotated component (necessitating a driving motor and longer measurement time whence this concept is far from being suitable for real-time use) and of the latter is its price and higher complexity of the optical layout. The use of micropolarizers in a digital polariscope removes all stated disadvantages, hence such a polariscope processes a single beam (no need of beam-splitting) and one fringe pattern (no need of a rotating analyzer).","PeriodicalId":267447,"journal":{"name":"Proceedings of 21st International Conference Radioelektronika 2011","volume":"214 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121546051","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 : 2011-04-19DOI: 10.1109/RADIOELEK.2011.5936446
J. Šimša
The paper brings some major points of application of signal subspace methods in linear mean square error (MSE) detectors of direct sequence CDMA signals. Focusing on the cross-spectral (CS) method, its origin and a relation to multistage Wiener filter (MWF) is shown. This filter results from splitting of correlation matrix to the shape which does not contain the inversion of the initial correlation matrix.
{"title":"Subspace methods in linear DS-CDMA detection","authors":"J. Šimša","doi":"10.1109/RADIOELEK.2011.5936446","DOIUrl":"https://doi.org/10.1109/RADIOELEK.2011.5936446","url":null,"abstract":"The paper brings some major points of application of signal subspace methods in linear mean square error (MSE) detectors of direct sequence CDMA signals. Focusing on the cross-spectral (CS) method, its origin and a relation to multistage Wiener filter (MWF) is shown. This filter results from splitting of correlation matrix to the shape which does not contain the inversion of the initial correlation matrix.","PeriodicalId":267447,"journal":{"name":"Proceedings of 21st International Conference Radioelektronika 2011","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131253929","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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