Pub Date : 2007-12-04DOI: 10.1109/ISWCS.2007.4392361
Hiroyuki Hatano, T. Yamazato, M. Katayama
We consider an application of a ultrasonic array emitter to automotive targets detection systems for short-range. Ultrasonic sensors are low cost and widely used. However detectable ranges do not meet the requirements for short-range applications, such as parking aid systems. In this paper, we propose a method which may achieve the emission to a desired area within limited time. We evaluate the expected accuracy of target position estimations by computer simulations. As a result, we show the ability of the ultrasonic sensors for parking aid systems.
{"title":"Automotive Ultrasonic Array Emitter for Short-range Targets Detection","authors":"Hiroyuki Hatano, T. Yamazato, M. Katayama","doi":"10.1109/ISWCS.2007.4392361","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392361","url":null,"abstract":"We consider an application of a ultrasonic array emitter to automotive targets detection systems for short-range. Ultrasonic sensors are low cost and widely used. However detectable ranges do not meet the requirements for short-range applications, such as parking aid systems. In this paper, we propose a method which may achieve the emission to a desired area within limited time. We evaluate the expected accuracy of target position estimations by computer simulations. As a result, we show the ability of the ultrasonic sensors for parking aid systems.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122468206","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392450
P. Vieira, Tiago Rosa Maria Paula Queluz, A. Rodrigues
In this paper a realistic directional channel model that is an extension of COST 273 channel model is presented. The model uses a previously developed cluster and visibility generation strategy with increased realism, due to the introduction of terrain and clutter information. The new model was implemented using terrain, clutter, street and user mobility information for the city of Lisbon,Portugal. The simulation analysis was performed and joint statistical properties of azimuth spread and delay spread were compared with other models and available experimental data. The introduction of clutter and terrain information into the simulations produces an increase on multi-path delay and azimuth spread, underlining Lisbon bad urban characteristics.
{"title":"Terrain and Clutter Impact on Joint Statistical Properties of Azimuth Spread and Delay Spread in Macro-cell Bad Urban Environment","authors":"P. Vieira, Tiago Rosa Maria Paula Queluz, A. Rodrigues","doi":"10.1109/ISWCS.2007.4392450","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392450","url":null,"abstract":"In this paper a realistic directional channel model that is an extension of COST 273 channel model is presented. The model uses a previously developed cluster and visibility generation strategy with increased realism, due to the introduction of terrain and clutter information. The new model was implemented using terrain, clutter, street and user mobility information for the city of Lisbon,Portugal. The simulation analysis was performed and joint statistical properties of azimuth spread and delay spread were compared with other models and available experimental data. The introduction of clutter and terrain information into the simulations produces an increase on multi-path delay and azimuth spread, underlining Lisbon bad urban characteristics.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"18 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122470828","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392380
D. B. D. Costa, M. Yacoub
In this paper, general exact expressions for the level crossing rate and average fade duration of the envelope of multibranch diversity systems operating on independent non- identically distributed κ-μ fading channels are derived. Our analytical results are validated by reducing them to some particular known cases and by means of Monte Carlo simulation.
{"title":"Level crossing rates and average fade durations for multibranch diversity receivers operating onκ-μ fading channels","authors":"D. B. D. Costa, M. Yacoub","doi":"10.1109/ISWCS.2007.4392380","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392380","url":null,"abstract":"In this paper, general exact expressions for the level crossing rate and average fade duration of the envelope of multibranch diversity systems operating on independent non- identically distributed κ-μ fading channels are derived. Our analytical results are validated by reducing them to some particular known cases and by means of Monte Carlo simulation.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115191567","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392395
G. Binetti, G. Boggia, P. Camarda, L. Grieco
Anti-collision algorithms are responsible for fast and energy efficient identification of RFID tags. They can be classified in Tree or Aloha based. To exploit benefits of both approaches, in this paper, we present a hybrid anti-collision algorithm. We assume that each tag stores a unique product identifier (ID) and the output of a hash function applied to that ID, which is shorter than the entire ID. With the proposed algorithm, in a first step, the reader, exploiting a Query Tree approach, queries the tags trying to identify each tag ID with the corresponding digest. When a hash collision is revealed, a second step, based on Framed Slotted Aloha Protocol, is used by the reader to identify only tag IDs with same digest. Numerical results have shown that the developed method, when using the most general Electronic Product Code scheme for tags addressing, improves performance in terms of mean identification delay with respect to query based protocols. Moreover, it gets about the same performance of the Binary Tree protocol, but overcoming its principal drawbacks.
{"title":"A Hashing-based Anti-Collision Algorithm for RFID Tag Identification","authors":"G. Binetti, G. Boggia, P. Camarda, L. Grieco","doi":"10.1109/ISWCS.2007.4392395","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392395","url":null,"abstract":"Anti-collision algorithms are responsible for fast and energy efficient identification of RFID tags. They can be classified in Tree or Aloha based. To exploit benefits of both approaches, in this paper, we present a hybrid anti-collision algorithm. We assume that each tag stores a unique product identifier (ID) and the output of a hash function applied to that ID, which is shorter than the entire ID. With the proposed algorithm, in a first step, the reader, exploiting a Query Tree approach, queries the tags trying to identify each tag ID with the corresponding digest. When a hash collision is revealed, a second step, based on Framed Slotted Aloha Protocol, is used by the reader to identify only tag IDs with same digest. Numerical results have shown that the developed method, when using the most general Electronic Product Code scheme for tags addressing, improves performance in terms of mean identification delay with respect to query based protocols. Moreover, it gets about the same performance of the Binary Tree protocol, but overcoming its principal drawbacks.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115291552","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392442
G. Baruffa, Paolo Micanti, F. Frescura
The transmission of compressed video sequences over wireless networks represents a particularly challenging problem, since the obtained visual quality strongly depends on the characteristics of the error-prone channel and on the tools used to compress the original sequence. In this paper, we present some methods for error concealment and error correction, which can be used when JPEG 2000 is adopted as compression tool. A judicious use of the scalability properties, error correction tools supplied by this standard, and an appropriate data interleaving algorithm can provide a good performance when compared with other error recovery methods.
{"title":"Error Correction and Concealment for JPEG 2000 Video Transmitted over Wireless Networks","authors":"G. Baruffa, Paolo Micanti, F. Frescura","doi":"10.1109/ISWCS.2007.4392442","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392442","url":null,"abstract":"The transmission of compressed video sequences over wireless networks represents a particularly challenging problem, since the obtained visual quality strongly depends on the characteristics of the error-prone channel and on the tools used to compress the original sequence. In this paper, we present some methods for error concealment and error correction, which can be used when JPEG 2000 is adopted as compression tool. A judicious use of the scalability properties, error correction tools supplied by this standard, and an appropriate data interleaving algorithm can provide a good performance when compared with other error recovery methods.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115300055","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392386
J. Paavola, V. Ipatov
A method of increasing the capacity of synchronous DS-CDMA beyond the signal space dimension is called oversaturation. When the number of users exceeds the signal space dimension, it does not in principle prohibit the maximization of minimum Euclidean distance between the points of a group signal constellation up to the optimum achieved with orthogonal users' signatures. Previously reported construction of distance-optimal signature ensembles was limited to only signal space dimensions equal to the natural power of four. This paper presents a generalization of such a method to arbitrary signal space dimensions. Necessary condition of presenting binary antipodal alphabet in the oversaturated ensembles of this kind is also discussed.
{"title":"Distance-Optimal Oversaturated CDMA Signature Ensemble","authors":"J. Paavola, V. Ipatov","doi":"10.1109/ISWCS.2007.4392386","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392386","url":null,"abstract":"A method of increasing the capacity of synchronous DS-CDMA beyond the signal space dimension is called oversaturation. When the number of users exceeds the signal space dimension, it does not in principle prohibit the maximization of minimum Euclidean distance between the points of a group signal constellation up to the optimum achieved with orthogonal users' signatures. Previously reported construction of distance-optimal signature ensembles was limited to only signal space dimensions equal to the natural power of four. This paper presents a generalization of such a method to arbitrary signal space dimensions. Necessary condition of presenting binary antipodal alphabet in the oversaturated ensembles of this kind is also discussed.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":" 16","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113947920","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392321
A. Ayman, Abdel-Samad
In this paper we present and compare several low-complexity approaches for soft-output equalization using reduced-state sequence estimation (RSSE) for EDGE. The proposed approaches require only a forward equalization pass and have the same complexity as hard-output RSSE equalization. However, they offer performance gains close to more complicated approaches that require both forward and backward passes.
{"title":"Low-Complexity Soft-Output Reduced-State Equalization for EDGE","authors":"A. Ayman, Abdel-Samad","doi":"10.1109/ISWCS.2007.4392321","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392321","url":null,"abstract":"In this paper we present and compare several low-complexity approaches for soft-output equalization using reduced-state sequence estimation (RSSE) for EDGE. The proposed approaches require only a forward equalization pass and have the same complexity as hard-output RSSE equalization. However, they offer performance gains close to more complicated approaches that require both forward and backward passes.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"253 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113991336","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392299
T. Fernández, J. Rodas, C. Escudero, D. Iglesia
Positioning systems based on sensor networks is one of the most promising fields in mobile computing. This paper considers the Bluetooth standard to locate devices using the RSSI (Received Signal Strength Indicator). The major problem of working with this parameter is its fluctuation that happens very fast due to changes in the environment. These changes can be caused by humidity or temperature, presence and movement of people, opening and closing of doors, multipath effect, etc... This paper introduces an innovative approach that uses the RSSI information between several fixed wireless beacons to improve the reliability of a Bluetooth positioning system. This information is used to calibrate the sensor responses. The results of several experiments illustrate how the real time calibration improves the precision and the stabilization of the position estimations. Moreover, we show the improvement obtained when increasing the number of beacons.
{"title":"Bluetooth Sensor Network Positioning System with Dynamic Calibration","authors":"T. Fernández, J. Rodas, C. Escudero, D. Iglesia","doi":"10.1109/ISWCS.2007.4392299","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392299","url":null,"abstract":"Positioning systems based on sensor networks is one of the most promising fields in mobile computing. This paper considers the Bluetooth standard to locate devices using the RSSI (Received Signal Strength Indicator). The major problem of working with this parameter is its fluctuation that happens very fast due to changes in the environment. These changes can be caused by humidity or temperature, presence and movement of people, opening and closing of doors, multipath effect, etc... This paper introduces an innovative approach that uses the RSSI information between several fixed wireless beacons to improve the reliability of a Bluetooth positioning system. This information is used to calibrate the sensor responses. The results of several experiments illustrate how the real time calibration improves the precision and the stabilization of the position estimations. Moreover, we show the improvement obtained when increasing the number of beacons.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121891253","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392356
A. Mitseva, M. Gerlach, N. Prasad
In the emerging hybrid hierarchical network model for wireless sensor networks, confidential and private data for end users is processed in some distinctive scenarios. In this respect, preserving privacy and establishing trust is a challenging task. This paper presents solutions to privacy issues based on context aware privacy protection and trust establishment mechanisms in hybrid hierarchical architecture. Based on two scenarios where this framework can be applied to - a medical scenario and vehicle network scenario-relevant privacy mechanisms are derived. It is shown, that context aware privacy protection is crucial for networks applying the HHA and hence context aware anonymization and trust establishment algorithms are introduced. An evaluation of the algorithms and analysis of the influence of the complexity of the context attributes are presented.
{"title":"Privacy Protection Mechanisms for Hybrid Hierarchical Wireless Sensor Networks","authors":"A. Mitseva, M. Gerlach, N. Prasad","doi":"10.1109/ISWCS.2007.4392356","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392356","url":null,"abstract":"In the emerging hybrid hierarchical network model for wireless sensor networks, confidential and private data for end users is processed in some distinctive scenarios. In this respect, preserving privacy and establishing trust is a challenging task. This paper presents solutions to privacy issues based on context aware privacy protection and trust establishment mechanisms in hybrid hierarchical architecture. Based on two scenarios where this framework can be applied to - a medical scenario and vehicle network scenario-relevant privacy mechanisms are derived. It is shown, that context aware privacy protection is crucial for networks applying the HHA and hence context aware anonymization and trust establishment algorithms are introduced. An evaluation of the algorithms and analysis of the influence of the complexity of the context attributes are presented.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115511963","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 : 2007-12-04DOI: 10.1109/ISWCS.2007.4392388
M. A. El-Nasr, H. Shaban, M. Mangoud
Effects of multiple access interference (MAI) and frequency offset on bit error rate (BER) performance of synchronous coded minimum shift keying/multi-carrier code division multiple access (MSK/MC-CDMA) systems were considered using standard Gaussian approximation (SGA). Simulations were carried out in AWGN and frequency selective Rayleigh fading channels. Results showed that the un-coded MSK/MC-CDMA system under investigation outperforms the corresponding system with BPSK modulation. Furthermore, coded MSK/MC-CDMA can achieve a better performance than the theoretical performance in AWGN channel for a single user, even in the presence of MAI.
{"title":"Effect of MAI and Frequency Offset on the Performance of Coded MC-CDMA Synchronous Downlink Systems with MSK Modulation","authors":"M. A. El-Nasr, H. Shaban, M. Mangoud","doi":"10.1109/ISWCS.2007.4392388","DOIUrl":"https://doi.org/10.1109/ISWCS.2007.4392388","url":null,"abstract":"Effects of multiple access interference (MAI) and frequency offset on bit error rate (BER) performance of synchronous coded minimum shift keying/multi-carrier code division multiple access (MSK/MC-CDMA) systems were considered using standard Gaussian approximation (SGA). Simulations were carried out in AWGN and frequency selective Rayleigh fading channels. Results showed that the un-coded MSK/MC-CDMA system under investigation outperforms the corresponding system with BPSK modulation. Furthermore, coded MSK/MC-CDMA can achieve a better performance than the theoretical performance in AWGN channel for a single user, even in the presence of MAI.","PeriodicalId":261480,"journal":{"name":"2007 4th International Symposium on Wireless Communication Systems","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123093361","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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