In this paper, we propose a modified version of the well-known delay looked loop (DLL) timing synchronizer, which is specifically designed to take into account the characteristics of a class of receiver architectures that has been experiencing a renewed interest in the frame of ultra wide band (UWB) transmission systems, i.e., the Differential Transmitted Reference (DTR) receiver. The proposed solution requires average channel state information (A-CSI) for system and parameters optimization, but it is shown in this paper that it can efficiently work in typical multipath fading channels, where UWB systems are expected to operate. Simulation results will be also provided to show the performance of the proposed method.
{"title":"A modified Delay Locked Loop synchronizer for ranging-based fine timing acquisition of Differential Transmitted Reference UWB receivers","authors":"M. Renzo, F. Graziosi, F. Santucci","doi":"10.1109/EW.2008.4623870","DOIUrl":"https://doi.org/10.1109/EW.2008.4623870","url":null,"abstract":"In this paper, we propose a modified version of the well-known delay looked loop (DLL) timing synchronizer, which is specifically designed to take into account the characteristics of a class of receiver architectures that has been experiencing a renewed interest in the frame of ultra wide band (UWB) transmission systems, i.e., the Differential Transmitted Reference (DTR) receiver. The proposed solution requires average channel state information (A-CSI) for system and parameters optimization, but it is shown in this paper that it can efficiently work in typical multipath fading channels, where UWB systems are expected to operate. Simulation results will be also provided to show the performance of the proposed method.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129975257","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}
Tail-biting convolutional codes (TBCC) are simple and powerful forward error correction (FEC) codes. They have been adopted as the FEC scheme for data and/or overhead channels in many wireless communications systems, including IS-54, EDGE, WiMAX and LTE. A convolutional code is called tail-biting (or circular) if the beginning state of its encoding trellis is always equal to the ending state after encoding. However, the circular state information is not available to the receiver. One important task in decoding TBCC is to estimate the circular state based on the received soft bit values. Many efficient algorithms have been proposed for decoding TBCC. Among them the wrap-around Viterbi algorithm (WAVA) provides near-ML (maximum likelihood) performances with the lowest complexity. In this paper, we propose several algorithms to further reduce the average number of decoding iterations and the memory usage in WAVA. Simulation results show that the complexity reduction from our proposed algorithms comes with no or almost negligible performance degradation.
{"title":"Reduced-complexity wrap-around Viterbi algorithm for decoding tail-biting convolutional codes","authors":"Tsao-Tsen Chen, Shiau-He Tsai","doi":"10.1109/EW.2008.4623841","DOIUrl":"https://doi.org/10.1109/EW.2008.4623841","url":null,"abstract":"Tail-biting convolutional codes (TBCC) are simple and powerful forward error correction (FEC) codes. They have been adopted as the FEC scheme for data and/or overhead channels in many wireless communications systems, including IS-54, EDGE, WiMAX and LTE. A convolutional code is called tail-biting (or circular) if the beginning state of its encoding trellis is always equal to the ending state after encoding. However, the circular state information is not available to the receiver. One important task in decoding TBCC is to estimate the circular state based on the received soft bit values. Many efficient algorithms have been proposed for decoding TBCC. Among them the wrap-around Viterbi algorithm (WAVA) provides near-ML (maximum likelihood) performances with the lowest complexity. In this paper, we propose several algorithms to further reduce the average number of decoding iterations and the memory usage in WAVA. Simulation results show that the complexity reduction from our proposed algorithms comes with no or almost negligible performance degradation.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131554786","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}
Eunhye Nam, Namjeong Lee, Keonkook Lee, Joonhyuk Kang, Youngok Kim
Space-time block code from coordinate interleaved orthogonal design (STBC-CIOD) is considered as an effective transmit diversity scheme for achieving full-rate and full-diversity with low decoding complexity. The simple maximum likelihood (SML) decoder for STBC-CIOD is known to be an optimal decoder in time-invariant channel. However, the performance of the SML decoder is inevitably degraded when the channel becomes time-varying. In this paper, we propose a computationally efficient near-optimal decoding algorithm for STBC-CIOD to mitigate the interference caused by time-selectivity of the channel. The algorithm establishes partial candidate sequences and iteratively finds the best sequence among the sequences through metric comparison. Simulation results show that the proposed decoder outperforms the SML decoder and achieves near-optimal performance with significantly low complexity.
坐标交错正交设计空时分组码(STBC-CIOD)被认为是一种有效的传输分集方案，可以在较低的译码复杂度下实现全速率和全分集。STBC-CIOD的简单最大似然解码器(simple maximum likelihood, SML)是公认的时不变信道下的最佳解码器。然而，当信道时变时，SML解码器的性能不可避免地会下降。在本文中，我们提出了一种计算效率高的近最优STBC-CIOD解码算法，以减轻信道时间选择性引起的干扰。该算法首先建立部分候选序列，并通过度量比较在序列中迭代找到最优序列。仿真结果表明，该解码器的性能优于SML解码器，且复杂度显著降低，性能接近最优。
{"title":"Iterative near-optimal decoder for STBC from CIOD over time-varying channel","authors":"Eunhye Nam, Namjeong Lee, Keonkook Lee, Joonhyuk Kang, Youngok Kim","doi":"10.1109/EW.2008.4623866","DOIUrl":"https://doi.org/10.1109/EW.2008.4623866","url":null,"abstract":"Space-time block code from coordinate interleaved orthogonal design (STBC-CIOD) is considered as an effective transmit diversity scheme for achieving full-rate and full-diversity with low decoding complexity. The simple maximum likelihood (SML) decoder for STBC-CIOD is known to be an optimal decoder in time-invariant channel. However, the performance of the SML decoder is inevitably degraded when the channel becomes time-varying. In this paper, we propose a computationally efficient near-optimal decoding algorithm for STBC-CIOD to mitigate the interference caused by time-selectivity of the channel. The algorithm establishes partial candidate sequences and iteratively finds the best sequence among the sequences through metric comparison. Simulation results show that the proposed decoder outperforms the SML decoder and achieves near-optimal performance with significantly low complexity.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115372647","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}
Direct sequence ultra wide band (DS-UWB) is a wireless communication technique using codes to spread the transmitted data over a bandwidth in the order of 1.3 GHz. As the targeted data rate increases, shorter spreading codes are used, leading to a higher sensitivity to inter symbol interference (ISI). This paper presents a comparative study on the effect of different spreading codes on the system performance. The results show that the use of m-sequences increase the system performance in the case of BPSK modulation, at the cost of a decreased scalability in terms of available data rates. For 4BOK modulation, we present original coding schemes leading to an increased robustness to ISI in the case of uncoded communication. These results confirm that ISI can effectively be mitigated by using specifically optimized spreading codes.
{"title":"Evaluation of the DS-UWB system performance using innovative spreading codes","authors":"P. Pagani","doi":"10.1109/EW.2008.4623871","DOIUrl":"https://doi.org/10.1109/EW.2008.4623871","url":null,"abstract":"Direct sequence ultra wide band (DS-UWB) is a wireless communication technique using codes to spread the transmitted data over a bandwidth in the order of 1.3 GHz. As the targeted data rate increases, shorter spreading codes are used, leading to a higher sensitivity to inter symbol interference (ISI). This paper presents a comparative study on the effect of different spreading codes on the system performance. The results show that the use of m-sequences increase the system performance in the case of BPSK modulation, at the cost of a decreased scalability in terms of available data rates. For 4BOK modulation, we present original coding schemes leading to an increased robustness to ISI in the case of uncoded communication. These results confirm that ISI can effectively be mitigated by using specifically optimized spreading codes.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"298 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124261699","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}
Na-young Kim, Sujin Kim, Jaehwan Kim, Jeongsu Lee, Joonhyuk Kang
In this paper, we propose an efficient ranging technique using chirp signal, which employs a matrix pencil method to estimate time of arrival (TOA). The proposed TOA estimation method consists of a two-step signal processing: minimum mean square error (MMSE)-based channel impulse response estimation and the channel delay tracking by matrix pencil algorithm. At the first step, the transmitted known chirp signals are cancelled out using the MMSE criterion. Then, the delay components are extracted by matrix pencil method using the estimated frequency channel impulse response. Simulation results show that the proposed scheme achieves small ranging error with low complexity.
{"title":"Efficient indoor ranging algorithm using chirp signalling","authors":"Na-young Kim, Sujin Kim, Jaehwan Kim, Jeongsu Lee, Joonhyuk Kang","doi":"10.1109/EW.2008.4623850","DOIUrl":"https://doi.org/10.1109/EW.2008.4623850","url":null,"abstract":"In this paper, we propose an efficient ranging technique using chirp signal, which employs a matrix pencil method to estimate time of arrival (TOA). The proposed TOA estimation method consists of a two-step signal processing: minimum mean square error (MMSE)-based channel impulse response estimation and the channel delay tracking by matrix pencil algorithm. At the first step, the transmitted known chirp signals are cancelled out using the MMSE criterion. Then, the delay components are extracted by matrix pencil method using the estimated frequency channel impulse response. Simulation results show that the proposed scheme achieves small ranging error with low complexity.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115128934","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}
Massimo Colonna, G. Zarba, E. Buracchini, P. Goria, A. Trogolo, S. Barberis
In the last years many different technologies and air interfaces have been standardized. B3G systems will allow the integration and coexistence of these diverse technologies in a common environment. It is a priority objective of this scenario of have a flexible terminal that can dynamically select the most appropriate RAT and reconfigure itself from the physical to the application layer. This reconfiguration can be carried out by downloading the various software modules that form the new RAT through the air interface on which it is currently operating. The aim of this paper is to evaluate the performance of the software download procedure when the terminal is operating in an IEEE 802.11 WLAN.
{"title":"Performance evaluation of the software download procedure in an IEEE 802.11 WLAN","authors":"Massimo Colonna, G. Zarba, E. Buracchini, P. Goria, A. Trogolo, S. Barberis","doi":"10.1109/EW.2008.4623928","DOIUrl":"https://doi.org/10.1109/EW.2008.4623928","url":null,"abstract":"In the last years many different technologies and air interfaces have been standardized. B3G systems will allow the integration and coexistence of these diverse technologies in a common environment. It is a priority objective of this scenario of have a flexible terminal that can dynamically select the most appropriate RAT and reconfigure itself from the physical to the application layer. This reconfiguration can be carried out by downloading the various software modules that form the new RAT through the air interface on which it is currently operating. The aim of this paper is to evaluate the performance of the software download procedure when the terminal is operating in an IEEE 802.11 WLAN.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116882275","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}
In this paper we proposed a novel self-organized message dissemination algorithm, namely the cluster-based broadcast (CB), for the emergency electronic brake light (EEBL) application in vehicular ad-hoc networks (VANET). The proposed cluster-based broadcast algorithm converts multihop broadcast message forwarding into multiple of single-hop broadcast clusters, which offers higher reliability, lower channel usage and message propagation delay in comparison with the traditional Directional Flooding (DF). Furthermore, we study the depedence of EEBL application on the market penetration ratio of the VANET wireless communication nodes. An innovative idea of combining the VANET with nomadic devices is proposed in this work to mitigate the slow market penetration rate problem. The results show that the nomadic devices, like portable navigation devices with communication ability, will play an important role when the VANET technology is rolling out in our real life.
{"title":"Wireless local danger warning using inter-vehicle communications in highway scenarios","authors":"Yunpeng Zang, Lothar Stibor, Hans-Jürgen Reumerman, Hui Chen","doi":"10.1109/EW.2008.4623905","DOIUrl":"https://doi.org/10.1109/EW.2008.4623905","url":null,"abstract":"In this paper we proposed a novel self-organized message dissemination algorithm, namely the cluster-based broadcast (CB), for the emergency electronic brake light (EEBL) application in vehicular ad-hoc networks (VANET). The proposed cluster-based broadcast algorithm converts multihop broadcast message forwarding into multiple of single-hop broadcast clusters, which offers higher reliability, lower channel usage and message propagation delay in comparison with the traditional Directional Flooding (DF). Furthermore, we study the depedence of EEBL application on the market penetration ratio of the VANET wireless communication nodes. An innovative idea of combining the VANET with nomadic devices is proposed in this work to mitigate the slow market penetration rate problem. The results show that the nomadic devices, like portable navigation devices with communication ability, will play an important role when the VANET technology is rolling out in our real life.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"177 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129574647","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}
In this paper, we present a new method to analyze the performance of automatic repeat request (ARQ) schemes in self-similar traffic for the future service-oriented Internet. Taking into account the self-similar traffic of a massive-scale wireless multimedia service, we build a batch arrival queueing model and suppose the batch size is a random variable following Pareto (c, alpha) distribution. Considering the delay in the setting up procedure of a data link, we introduce a setup strategy in this queueing model. Thus a batch arrival Geomxi/G/1 queueing system with setup is built in this paper. We give the formula for performance measures in terms of setup ratio and offered load for different ARQ schemes. Numerical results are given to evaluate the performance of the system and to show influence of the self-similar degree and the delay of the setup procedure on these system performance.
{"title":"Performance analysis of self-similar traffic for future service-oriented internet","authors":"Shunfu Jin, Wuyi Yue, N. Tian","doi":"10.1109/EW.2008.4623897","DOIUrl":"https://doi.org/10.1109/EW.2008.4623897","url":null,"abstract":"In this paper, we present a new method to analyze the performance of automatic repeat request (ARQ) schemes in self-similar traffic for the future service-oriented Internet. Taking into account the self-similar traffic of a massive-scale wireless multimedia service, we build a batch arrival queueing model and suppose the batch size is a random variable following Pareto (c, alpha) distribution. Considering the delay in the setting up procedure of a data link, we introduce a setup strategy in this queueing model. Thus a batch arrival Geomxi/G/1 queueing system with setup is built in this paper. We give the formula for performance measures in terms of setup ratio and offered load for different ARQ schemes. Numerical results are given to evaluate the performance of the system and to show influence of the self-similar degree and the delay of the setup procedure on these system performance.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121332713","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}
This paper studies the performance of orthogonal frequency division multiple access (OFDMA) in the multiuser multicarrier MIMO (M3) system for both uplink (UL) and down-link (DL) channels. We numerically quantify the performance gap between OFDMA and the optimal multicarrier solution. We also derive simple but near optimal algorithms to solve the generic OFDMA resource allocation problem in different scenarios.
{"title":"OFDMA capacity analysis and subcarrier allocation in MIMO Channels","authors":"Hongxiang Li, Younsun Kim, Hui Liu","doi":"10.1109/EW.2008.4623888","DOIUrl":"https://doi.org/10.1109/EW.2008.4623888","url":null,"abstract":"This paper studies the performance of orthogonal frequency division multiple access (OFDMA) in the multiuser multicarrier MIMO (M3) system for both uplink (UL) and down-link (DL) channels. We numerically quantify the performance gap between OFDMA and the optimal multicarrier solution. We also derive simple but near optimal algorithms to solve the generic OFDMA resource allocation problem in different scenarios.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114070124","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}
D. Skoutas, Dimitris I. Komnakos, D. Vouyioukas, A. Rouskas
Enhanced Uplink operation of WCDMA-UMTS systems utilizes fast Node B scheduling and a short Transmission Time Interval (TTI) of 2ms. The scheduling decisions are based on scheduling information (SI) sent by each UE to the Node B. The main drawback of the current scheduling procedure is that the SI does not include any information regarding the delay sensitivity of each traffic flow, as well as the actual delay that the buffered data have experienced. In this paper, we propose the inclusion of such information in SI by introducing a modification of the respective 3GPP specifications. Furthermore, we propose a Dynamic Priority Scheduler (DPS), which can utilize this new information. The performance of the proposed scheme is evaluated by means of system level simulations.
{"title":"Enhanced dedicated channel scheduling optimization in WCDMA","authors":"D. Skoutas, Dimitris I. Komnakos, D. Vouyioukas, A. Rouskas","doi":"10.1109/EW.2008.4623867","DOIUrl":"https://doi.org/10.1109/EW.2008.4623867","url":null,"abstract":"Enhanced Uplink operation of WCDMA-UMTS systems utilizes fast Node B scheduling and a short Transmission Time Interval (TTI) of 2ms. The scheduling decisions are based on scheduling information (SI) sent by each UE to the Node B. The main drawback of the current scheduling procedure is that the SI does not include any information regarding the delay sensitivity of each traffic flow, as well as the actual delay that the buffered data have experienced. In this paper, we propose the inclusion of such information in SI by introducing a modification of the respective 3GPP specifications. Furthermore, we propose a Dynamic Priority Scheduler (DPS), which can utilize this new information. The performance of the proposed scheme is evaluated by means of system level simulations.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"177 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121047507","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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