Pub Date : 2004-12-01DOI: 10.1109/UWBST.2003.1267867
Yuichiro Shimizu, Y. Sanada
Since very short pulse waves are transmitted, UWB systems have excellent accuracy in terms of distance measurement. In order to measure the distance between the terminals, the transmitted pulses have to be synchronized by a delay-lock-loop (DLL) in the receiver. In this paper the performance of the DLL is evaluated. Its performance depends the timing jitter between the local clocks of the terminals.
{"title":"Accuracy of relative distance measurement with ultra wideband system","authors":"Yuichiro Shimizu, Y. Sanada","doi":"10.1109/UWBST.2003.1267867","DOIUrl":"https://doi.org/10.1109/UWBST.2003.1267867","url":null,"abstract":"Since very short pulse waves are transmitted, UWB systems have excellent accuracy in terms of distance measurement. In order to measure the distance between the terminals, the transmitted pulses have to be synchronized by a delay-lock-loop (DLL) in the receiver. In this paper the performance of the DLL is evaluated. Its performance depends the timing jitter between the local clocks of the terminals.","PeriodicalId":218975,"journal":{"name":"IEEE Conference on Ultra Wideband Systems and Technologies, 2003","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116677339","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 : 2004-08-01DOI: 10.1109/UWBST.2003.1267802
T. Ezaki, T. Ohtsuki
In this paper, we propose a time interleave (TI)-ultra wideband (UWB)-impulse radio (IR) system where N/sub f/ monocycle pulses per information symbol are transmitted not continuously but discontinuously through the time interleaver to get more time diversity. Moreover, we compare the diversity gains of the UWB-IR systems on block fading channels with the fading block size q: the UWB-IR system with a single transmit antenna, the space time (ST)-UWB-IR system with N/sub t/ transmit antennas, and the TI-UWB-IR system with a single transmit antenna. Simulation results show that when the number of transmit antennas N/sub t/ is larger than or equal to the fading block size q, all the systems can achieve the same diversity gain. When the number of transmit antennas N/sub t/ is smaller than the fading block size q, the TI-UWB-IR system can achieve the largest diversity gain, and the ST-UWB-IR system and the UWB-IR system follow in order.
{"title":"Diversity gain in ultra wideband impulse radio (UWB-IR)","authors":"T. Ezaki, T. Ohtsuki","doi":"10.1109/UWBST.2003.1267802","DOIUrl":"https://doi.org/10.1109/UWBST.2003.1267802","url":null,"abstract":"In this paper, we propose a time interleave (TI)-ultra wideband (UWB)-impulse radio (IR) system where N/sub f/ monocycle pulses per information symbol are transmitted not continuously but discontinuously through the time interleaver to get more time diversity. Moreover, we compare the diversity gains of the UWB-IR systems on block fading channels with the fading block size q: the UWB-IR system with a single transmit antenna, the space time (ST)-UWB-IR system with N/sub t/ transmit antennas, and the TI-UWB-IR system with a single transmit antenna. Simulation results show that when the number of transmit antennas N/sub t/ is larger than or equal to the fading block size q, all the systems can achieve the same diversity gain. When the number of transmit antennas N/sub t/ is smaller than the fading block size q, the TI-UWB-IR system can achieve the largest diversity gain, and the ST-UWB-IR system and the UWB-IR system follow in order.","PeriodicalId":218975,"journal":{"name":"IEEE Conference on Ultra Wideband Systems and Technologies, 2003","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122129162","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 : 2003-11-16DOI: 10.1109/UWBST.2003.1267843
Jac Romme, B. Kull
The paper focuses on the effect of small-scale fading on the throughput of communication systems that operate with different bandwidth within an indoor environment. The small-scale fading of the indoor radio channel has been measured within an office environment. From these measurements, a single intuitive scalar is derived, which characterizes the small-scale fading encountered by a certain signal. This signal has been characterized by its lower frequency and bandwidth. This measure allows for an objective, quantitative analysis of the relation between small-scale fading and signal bandwidth. The paper is complemented by a link-budget analysis to illuminate the relationship between signal bandwidth, fading margin and throughput. The bandwidth has been varied step-wise from 10 MHz to 5 GHz.
{"title":"On the relation between bandwidth and robustness of indoor UWB communication","authors":"Jac Romme, B. Kull","doi":"10.1109/UWBST.2003.1267843","DOIUrl":"https://doi.org/10.1109/UWBST.2003.1267843","url":null,"abstract":"The paper focuses on the effect of small-scale fading on the throughput of communication systems that operate with different bandwidth within an indoor environment. The small-scale fading of the indoor radio channel has been measured within an office environment. From these measurements, a single intuitive scalar is derived, which characterizes the small-scale fading encountered by a certain signal. This signal has been characterized by its lower frequency and bandwidth. This measure allows for an objective, quantitative analysis of the relation between small-scale fading and signal bandwidth. The paper is complemented by a link-budget analysis to illuminate the relationship between signal bandwidth, fading margin and throughput. The bandwidth has been varied step-wise from 10 MHz to 5 GHz.","PeriodicalId":218975,"journal":{"name":"IEEE Conference on Ultra Wideband Systems and Technologies, 2003","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123275922","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 : 2003-11-16DOI: 10.1109/UWBST.2003.1267887
B. Firoozbakhsh, T. Pratt, N. Jayant
The performance of an ultra-wideband receiver in the presence of IEEE 802.11a interference is evaluated. A mathematical expression for the interference is presented, and a closed-form solution for the interference on an UWB system employing the second derivative Gaussian monocycle is derived. The interference is characterized in terms of the receiver's bit error rates and throughputs. Our results indicate that, under certain conditions, the IEEE 802.11a interference can cause a significant increase in the bit error rate and a severe degradation of the attainable throughput of the UWB system.
{"title":"Analysis of IEEE 802.11a interference on UWB systems","authors":"B. Firoozbakhsh, T. Pratt, N. Jayant","doi":"10.1109/UWBST.2003.1267887","DOIUrl":"https://doi.org/10.1109/UWBST.2003.1267887","url":null,"abstract":"The performance of an ultra-wideband receiver in the presence of IEEE 802.11a interference is evaluated. A mathematical expression for the interference is presented, and a closed-form solution for the interference on an UWB system employing the second derivative Gaussian monocycle is derived. The interference is characterized in terms of the receiver's bit error rates and throughputs. Our results indicate that, under certain conditions, the IEEE 802.11a interference can cause a significant increase in the bit error rate and a severe degradation of the attainable throughput of the UWB system.","PeriodicalId":218975,"journal":{"name":"IEEE Conference on Ultra Wideband Systems and Technologies, 2003","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116381213","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 : 2003-11-16DOI: 10.1109/UWBST.2003.1267854
S. Licul, W. Davis, W. Stutzman
This paper introduces modeling of a ultra-wideband (UWB) communication link, using two monopole antennas, in terms of the singularity expansion method (SEM) via Prony's method. Prony's Method is used to extract poles and residues of the link. By obtaining the poles and residues of the link it is possible to construct a transfer function of the link in both time and frequency domains. This representation is a convenient way of characterizing and modeling a UWB communication system with a reduced number of parameters.
{"title":"Ultra-wideband (UWB) communication link modeling and characterization","authors":"S. Licul, W. Davis, W. Stutzman","doi":"10.1109/UWBST.2003.1267854","DOIUrl":"https://doi.org/10.1109/UWBST.2003.1267854","url":null,"abstract":"This paper introduces modeling of a ultra-wideband (UWB) communication link, using two monopole antennas, in terms of the singularity expansion method (SEM) via Prony's method. Prony's Method is used to extract poles and residues of the link. By obtaining the poles and residues of the link it is possible to construct a transfer function of the link in both time and frequency domains. This representation is a convenient way of characterizing and modeling a UWB communication system with a reduced number of parameters.","PeriodicalId":218975,"journal":{"name":"IEEE Conference on Ultra Wideband Systems and Technologies, 2003","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122558544","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 : 2003-11-16DOI: 10.1109/UWBST.2003.1267851
A. Muqaibel, A. Safaai‐Jazi, A. Attiya, A. Bayram, S. Riad
The propagation of ultra-wideband (UWB) signals in indoor environments is an important issue with significant impacts on the future direction and scope of the UWB technology and its applications. The objective of this article is to present an assessment of the potentials of UWB indoor communications by characterizing UWB indoor channels. The channel characterization refers to extracting the channel parameters from measured propagation data. An indoor UWB measurement campaign is undertaken. Time-domain indoor propagation measurements using pulses with FWHM equal to 85 ps are carried out. Typical indoor scenarios, including line-of-sight (LOS), non-line-of-sight (NLOS), room-to-room, within-the-room, and hallways are considered. Results of indoor propagation measurements are presented for local power delay profiles (local PDP) and small-scale averaged power delay profiles (SSA-PDP). Site-specific trends and general observations are discussed. The results for path-loss exponent and time dispersion parameters are presented.
{"title":"Measurement and characterization of indoor ultra-wideband propagation","authors":"A. Muqaibel, A. Safaai‐Jazi, A. Attiya, A. Bayram, S. Riad","doi":"10.1109/UWBST.2003.1267851","DOIUrl":"https://doi.org/10.1109/UWBST.2003.1267851","url":null,"abstract":"The propagation of ultra-wideband (UWB) signals in indoor environments is an important issue with significant impacts on the future direction and scope of the UWB technology and its applications. The objective of this article is to present an assessment of the potentials of UWB indoor communications by characterizing UWB indoor channels. The channel characterization refers to extracting the channel parameters from measured propagation data. An indoor UWB measurement campaign is undertaken. Time-domain indoor propagation measurements using pulses with FWHM equal to 85 ps are carried out. Typical indoor scenarios, including line-of-sight (LOS), non-line-of-sight (NLOS), room-to-room, within-the-room, and hallways are considered. Results of indoor propagation measurements are presented for local power delay profiles (local PDP) and small-scale averaged power delay profiles (SSA-PDP). Site-specific trends and general observations are discussed. The results for path-loss exponent and time dispersion parameters are presented.","PeriodicalId":218975,"journal":{"name":"IEEE Conference on Ultra Wideband Systems and Technologies, 2003","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122665960","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 : 2003-11-16DOI: 10.1109/UWBST.2003.1267800
S. Hoyos, Brian M. Sadler, G. Arce
This paper introduces novel techniques to perform analog to digital (AJD) conversion, based on the quantization of the coefficients obtained by the projection of a continuous-time signal over an orthogonal space. The new A/D techniques proposed here are motivated by the sampling of the input signal in domains which may lead to lower levels of signal distortion and significantly less demanding A/D conversion characteristics. As a particular case, we study A/D conversion in the frequency domain where samples of the signal spectrum are taken such that no time-aliasing occurs in the discrete-time version of the signal. We show that the frequency domain analog to digital converter (ADC) overcomes some of the difficulties encountered in conventional time-domain methods for A/D conversion of signals with very large bandwidths, such as ultra-wideband (UWB) signals. The discrete frequency samples are then passed through a vector quantizer with relaxed characteristics, operating over DC levels that change with a speed that is much lower than that required for time-domain A/D conversion. Fundamental figures of merit in A/D conversion and important system trade-offs are discussed for the proposed frequency domain ADC. As an example of this approach, we consider a multi-carrier UWB communications scheme.
{"title":"Analog to digital conversion of ultra-wideband signals in orthogonal spaces","authors":"S. Hoyos, Brian M. Sadler, G. Arce","doi":"10.1109/UWBST.2003.1267800","DOIUrl":"https://doi.org/10.1109/UWBST.2003.1267800","url":null,"abstract":"This paper introduces novel techniques to perform analog to digital (AJD) conversion, based on the quantization of the coefficients obtained by the projection of a continuous-time signal over an orthogonal space. The new A/D techniques proposed here are motivated by the sampling of the input signal in domains which may lead to lower levels of signal distortion and significantly less demanding A/D conversion characteristics. As a particular case, we study A/D conversion in the frequency domain where samples of the signal spectrum are taken such that no time-aliasing occurs in the discrete-time version of the signal. We show that the frequency domain analog to digital converter (ADC) overcomes some of the difficulties encountered in conventional time-domain methods for A/D conversion of signals with very large bandwidths, such as ultra-wideband (UWB) signals. The discrete frequency samples are then passed through a vector quantizer with relaxed characteristics, operating over DC levels that change with a speed that is much lower than that required for time-domain A/D conversion. Fundamental figures of merit in A/D conversion and important system trade-offs are discussed for the proposed frequency domain ADC. As an example of this approach, we consider a multi-carrier UWB communications scheme.","PeriodicalId":218975,"journal":{"name":"IEEE Conference on Ultra Wideband Systems and Technologies, 2003","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129365887","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 : 2003-11-16DOI: 10.1109/UWBST.2003.1267845
M. Y. Wah, Chia Yee, M. Yee
The existing regulatory limits tends to restrict the wireless range of UWB communications devices to several or tens of meters due to potential interference to existing spectrum users. This paper will introduce radio over fiber (ROF) to extend the range of wireless UWB radio. Existing ROF which uses single mode laser tends to be expensive. In this work, the radio frequency signal of UWB is transmitted over multimode fiber (MMF) using vertical cavity surface emitting lasers (VCSELs) and photo-receiver. This helps to realize a low cost distributed antenna system for both indoor and outdoor applications in UWB communications. Experimental results measured in both time and frequency domain are presented.
{"title":"Wireless ultra wideband communications using radio over fiber","authors":"M. Y. Wah, Chia Yee, M. Yee","doi":"10.1109/UWBST.2003.1267845","DOIUrl":"https://doi.org/10.1109/UWBST.2003.1267845","url":null,"abstract":"The existing regulatory limits tends to restrict the wireless range of UWB communications devices to several or tens of meters due to potential interference to existing spectrum users. This paper will introduce radio over fiber (ROF) to extend the range of wireless UWB radio. Existing ROF which uses single mode laser tends to be expensive. In this work, the radio frequency signal of UWB is transmitted over multimode fiber (MMF) using vertical cavity surface emitting lasers (VCSELs) and photo-receiver. This helps to realize a low cost distributed antenna system for both indoor and outdoor applications in UWB communications. Experimental results measured in both time and frequency domain are presented.","PeriodicalId":218975,"journal":{"name":"IEEE Conference on Ultra Wideband Systems and Technologies, 2003","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124597859","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 : 2003-11-16DOI: 10.1109/UWBST.2003.1267830
Y. Hong, A. Scaglione
Time synchronization has been an extremely difficult issue for wireless ad hoc networks due to its decentralized nature. Interestingly, synchrony have often been observed in swarms of biological systems such as that of synchronous flashing fireflies or spiking of neurons. In this paper, we utilize the narrow pulse characteristics of UWB systems to emulate the pulse-coupled integrate-and-fire (IF) model embedded in biological swarms in order to achieve distributed synchronization. The method is based on a simple transmission strategy where nodes integrate the coupling caused by the signal pulses received from other nodes, and fire a pulse after reaching a designated threshold. With time synchronization, many cooperative strategies can be applied to the network of distributed nodes. In particular, we show that synchronization can lead to coherent superposition of the signal pulses and it would allow to utilize the network as a distributed antenna array capable of reaching far receivers, solving the so called reach-back problem.
{"title":"Time synchronization and reach-back communications with pulse-coupled oscillators for UWB wireless ad hoc networks","authors":"Y. Hong, A. Scaglione","doi":"10.1109/UWBST.2003.1267830","DOIUrl":"https://doi.org/10.1109/UWBST.2003.1267830","url":null,"abstract":"Time synchronization has been an extremely difficult issue for wireless ad hoc networks due to its decentralized nature. Interestingly, synchrony have often been observed in swarms of biological systems such as that of synchronous flashing fireflies or spiking of neurons. In this paper, we utilize the narrow pulse characteristics of UWB systems to emulate the pulse-coupled integrate-and-fire (IF) model embedded in biological swarms in order to achieve distributed synchronization. The method is based on a simple transmission strategy where nodes integrate the coupling caused by the signal pulses received from other nodes, and fire a pulse after reaching a designated threshold. With time synchronization, many cooperative strategies can be applied to the network of distributed nodes. In particular, we show that synchronization can lead to coherent superposition of the signal pulses and it would allow to utilize the network as a distributed antenna array capable of reaching far receivers, solving the so called reach-back problem.","PeriodicalId":218975,"journal":{"name":"IEEE Conference on Ultra Wideband Systems and Technologies, 2003","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123464824","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 : 2003-11-16DOI: 10.1109/UWBST.2003.1267821
Honglei Zhang, Dennis Goeckel
Transmitted-reference (TR) ultra-wideband (UWB) wireless communication systems [R. Hoctor et al., Jan. 2002] can relax the difficult UWB timing requirements and can provide a simple receiver that gathers the energy from the many resolvable multipath components. However, TR-UWB's relatively poor bit error rate (BER) performance and low data rate have limited its application. In this paper, the TR-UWB idea is generalized to address both of these issues. In particular, the aspects of the system that provide the desirable multipath gathering ability and timing attributes are retained, while the remainder of the system is optimized, resulting in a significantly different signaling scheme and receiver back-end. Numerical results for two examples indicate a significant BER improvement over standard TR-UWB under the same timing requirement.
{"title":"Generalized transmitted-reference UWB systems","authors":"Honglei Zhang, Dennis Goeckel","doi":"10.1109/UWBST.2003.1267821","DOIUrl":"https://doi.org/10.1109/UWBST.2003.1267821","url":null,"abstract":"Transmitted-reference (TR) ultra-wideband (UWB) wireless communication systems [R. Hoctor et al., Jan. 2002] can relax the difficult UWB timing requirements and can provide a simple receiver that gathers the energy from the many resolvable multipath components. However, TR-UWB's relatively poor bit error rate (BER) performance and low data rate have limited its application. In this paper, the TR-UWB idea is generalized to address both of these issues. In particular, the aspects of the system that provide the desirable multipath gathering ability and timing attributes are retained, while the remainder of the system is optimized, resulting in a significantly different signaling scheme and receiver back-end. Numerical results for two examples indicate a significant BER improvement over standard TR-UWB under the same timing requirement.","PeriodicalId":218975,"journal":{"name":"IEEE Conference on Ultra Wideband Systems and Technologies, 2003","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114805816","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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