Pub Date : 2003-10-15DOI: 10.1109/WCT.2003.1321531
H. M. Karkhanechi, B.C. Levy
Multiple transmit and receive antennas can be used with orthogonal frequency division multiplexing to improve performance and transmission rate. In this paper we investigate trade offs between different techniques in broadband OFDM-based MIMO systems for achieving full diversity or maximum spatial multiplexing gain. The basic model of OFDM-based spatial multiplexer is very suitable for high data rate transmission, and if combined with other techniques such as channel coding or space time coding can provide desired diversity and spatial multiplexing gain.
{"title":"Spatial multiplexing and diversity gain in OFDM-based MIMO systems","authors":"H. M. Karkhanechi, B.C. Levy","doi":"10.1109/WCT.2003.1321531","DOIUrl":"https://doi.org/10.1109/WCT.2003.1321531","url":null,"abstract":"Multiple transmit and receive antennas can be used with orthogonal frequency division multiplexing to improve performance and transmission rate. In this paper we investigate trade offs between different techniques in broadband OFDM-based MIMO systems for achieving full diversity or maximum spatial multiplexing gain. The basic model of OFDM-based spatial multiplexer is very suitable for high data rate transmission, and if combined with other techniques such as channel coding or space time coding can provide desired diversity and spatial multiplexing gain.","PeriodicalId":6305,"journal":{"name":"2003 IEEE Topical Conference on Wireless Communication Technology","volume":"5 1","pages":"299-301"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84472591","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 : 2003-10-15DOI: 10.1109/WCT.2003.1321594
J. Andrews
This paper discusses the history of ultra-wideband (UWB) wireless and considers spectrum issues. It deals with UWB signal sources, including step, impulse, monocycle and RF pulses. It introduces new NLTL technology which can generate 6 V, 4 ps pulses and which could be used for 10 Gbit/s, millimeter wave, UWB wireless LAN. Several UWB antennas are presented including conical, TEM horn, D*dot, monopole and waveguide horn. Experimental proof is given that UWB free space propagation is not wavelength-dependent.
{"title":"UWB signal sources, antennas and propagation","authors":"J. Andrews","doi":"10.1109/WCT.2003.1321594","DOIUrl":"https://doi.org/10.1109/WCT.2003.1321594","url":null,"abstract":"This paper discusses the history of ultra-wideband (UWB) wireless and considers spectrum issues. It deals with UWB signal sources, including step, impulse, monocycle and RF pulses. It introduces new NLTL technology which can generate 6 V, 4 ps pulses and which could be used for 10 Gbit/s, millimeter wave, UWB wireless LAN. Several UWB antennas are presented including conical, TEM horn, D*dot, monopole and waveguide horn. Experimental proof is given that UWB free space propagation is not wavelength-dependent.","PeriodicalId":6305,"journal":{"name":"2003 IEEE Topical Conference on Wireless Communication Technology","volume":"57 1","pages":"439-440"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84759126","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 : 2003-10-15DOI: 10.1109/WCT.2003.1321504
A. Pham
The paper presents our on-going research on the development of carbon nanotube resonator sensors for chemical and, potentially, biological applications. The sensor transducer mechanism is based on changes of resonant frequency of an electromagnetic resonator coated with carbon nanotubes. We have developed carbon nanotube resonator sensor prototypes and found that the sensor is sensitive to both polar (NH/sub 3/) and non-polar gases (He, Ar, N/sub 2/, and O/sub 2/). In addition, we have recently demonstrated that the carbon nanotube resonator sensor is sensitive to organic solvents. This finding suggests that the carbon nanotube resonator sensors can be used to develop biosensors. The carbon nanotube resonator sensor platform has the potential to be incorporated in a wireless remote sensing system.
{"title":"Carbon nanotube resonator sensors for remote sensing systems","authors":"A. Pham","doi":"10.1109/WCT.2003.1321504","DOIUrl":"https://doi.org/10.1109/WCT.2003.1321504","url":null,"abstract":"The paper presents our on-going research on the development of carbon nanotube resonator sensors for chemical and, potentially, biological applications. The sensor transducer mechanism is based on changes of resonant frequency of an electromagnetic resonator coated with carbon nanotubes. We have developed carbon nanotube resonator sensor prototypes and found that the sensor is sensitive to both polar (NH/sub 3/) and non-polar gases (He, Ar, N/sub 2/, and O/sub 2/). In addition, we have recently demonstrated that the carbon nanotube resonator sensor is sensitive to organic solvents. This finding suggests that the carbon nanotube resonator sensors can be used to develop biosensors. The carbon nanotube resonator sensor platform has the potential to be incorporated in a wireless remote sensing system.","PeriodicalId":6305,"journal":{"name":"2003 IEEE Topical Conference on Wireless Communication Technology","volume":"327 1","pages":"233-236"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82930410","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 : 2003-10-15DOI: 10.1109/WCT.2003.1321508
T. Takeuchi, H. Mukai
The recent evolution of wireless LAN (WLAN) systems has accelerated the increase in access data rate. A data rate of 1 Gb/s will be the general demand in the near future, although the indoor wireless propagation environment will become more severe than the present situation. Thus, further detailed characteristics of the indoor wireless propagation environment will be necessary for realizing gigabit transmission in WLAN systems. The authors have been developing an indoor channel sounder suitable for characterizing individual ray components due to its very fine time delay resolution of 0.5 ns. The measurement signal of the sounder occupies more than 3 GHz bandwidth, so it can be called an ultra wide band (UWB) channel sounder. The paper shows some experimental approaches for indoor radio propagation measurements by UWB channel sounding.
{"title":"Ultra wide band channel sounding for indoor wireless propagation environments","authors":"T. Takeuchi, H. Mukai","doi":"10.1109/WCT.2003.1321508","DOIUrl":"https://doi.org/10.1109/WCT.2003.1321508","url":null,"abstract":"The recent evolution of wireless LAN (WLAN) systems has accelerated the increase in access data rate. A data rate of 1 Gb/s will be the general demand in the near future, although the indoor wireless propagation environment will become more severe than the present situation. Thus, further detailed characteristics of the indoor wireless propagation environment will be necessary for realizing gigabit transmission in WLAN systems. The authors have been developing an indoor channel sounder suitable for characterizing individual ray components due to its very fine time delay resolution of 0.5 ns. The measurement signal of the sounder occupies more than 3 GHz bandwidth, so it can be called an ultra wide band (UWB) channel sounder. The paper shows some experimental approaches for indoor radio propagation measurements by UWB channel sounding.","PeriodicalId":6305,"journal":{"name":"2003 IEEE Topical Conference on Wireless Communication Technology","volume":"79 1","pages":"246-247"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83810224","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 : 2003-10-15DOI: 10.1109/WCT.2003.1321454
J. Kim, E. Kim
In this paper, the performance of a CDMA multimedia packet transmission system is analyzed and simulated in an indoor wireless infrared channel. The indoor wireless infrared channel is modeled as a nondirected diffuse link, and pulse position modulation (PPM) is used as a modulation scheme. From the simulation results, it is shown that the RS coding is very effective in improving the packet-delay characteristics of the CDMA-based packet transmission system. The results of this paper can be applied to design of CDMA-based infrared indoor wireless LAN.
{"title":"Detection of CDMA multimedia packet in a wireless infrared channel","authors":"J. Kim, E. Kim","doi":"10.1109/WCT.2003.1321454","DOIUrl":"https://doi.org/10.1109/WCT.2003.1321454","url":null,"abstract":"In this paper, the performance of a CDMA multimedia packet transmission system is analyzed and simulated in an indoor wireless infrared channel. The indoor wireless infrared channel is modeled as a nondirected diffuse link, and pulse position modulation (PPM) is used as a modulation scheme. From the simulation results, it is shown that the RS coding is very effective in improving the packet-delay characteristics of the CDMA-based packet transmission system. The results of this paper can be applied to design of CDMA-based infrared indoor wireless LAN.","PeriodicalId":6305,"journal":{"name":"2003 IEEE Topical Conference on Wireless Communication Technology","volume":"12 1","pages":"126-129"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87465252","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 : 2003-10-15DOI: 10.1109/WCT.2003.1321569
Y. Hua, Yan Mei, Yu Chang
Summary form only given. The antenna is indispensable in wireless communications. An antenna array is well known for its power in harnessing spatially distributed radio energy for more reliable data reception. Current trends in smart antenna technology primarily focus on mobile environments where fast channel fading is predominant in limiting channel capacities. We present a new frontier in signal processing for wireless communications, which we call smart wireless antenna arrays or, more briefly, wireless antennas. Most (if not all) current antennas are wireless on one end but wired on the other. Wired antennas of large apertures are not always convenient for users. Therefore, we have endeavored to develop smarter antennas that have no wires. Our wireless antennas (or virtual antennas) are a number of wireless mobile relays distributed around a destination receiver (or a set of destination receivers). These relays could be embedded in any wireless mobile device. We show a signal processing framework for wireless antennas.
{"title":"Smart wireless antenna arrays","authors":"Y. Hua, Yan Mei, Yu Chang","doi":"10.1109/WCT.2003.1321569","DOIUrl":"https://doi.org/10.1109/WCT.2003.1321569","url":null,"abstract":"Summary form only given. The antenna is indispensable in wireless communications. An antenna array is well known for its power in harnessing spatially distributed radio energy for more reliable data reception. Current trends in smart antenna technology primarily focus on mobile environments where fast channel fading is predominant in limiting channel capacities. We present a new frontier in signal processing for wireless communications, which we call smart wireless antenna arrays or, more briefly, wireless antennas. Most (if not all) current antennas are wireless on one end but wired on the other. Wired antennas of large apertures are not always convenient for users. Therefore, we have endeavored to develop smarter antennas that have no wires. Our wireless antennas (or virtual antennas) are a number of wireless mobile relays distributed around a destination receiver (or a set of destination receivers). These relays could be embedded in any wireless mobile device. We show a signal processing framework for wireless antennas.","PeriodicalId":6305,"journal":{"name":"2003 IEEE Topical Conference on Wireless Communication Technology","volume":"131 1","pages":"384-385"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77208314","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 : 2003-10-15DOI: 10.1109/WCT.2003.1321463
Q. Chen, M. Kurahashi, K. Sawaya
Since various wireless communication services are available, it is required to make a mobile terminal which can handle several such services. Therefore, it is necessary to design a multimode, multifrequency antenna which has different polarization and radiation patterns at each band; the switching of the resonant modes should be controlled electronically. We propose a dual-mode patch antenna where a PIN diode switch is used to change the resonant mode of the antenna. The basic structure of the antenna is a planar inverted F-shape antenna (PIFA) with a PIN diode at the open terminal of the patch. The PIN diode is switched by the DC bias which is provided at the RF feed. When the PIN diode is biased forward (ON), the antenna operates as a loop antenna, while when the PIN diode is biased backward (OFF), the antenna works as a PIFA. The characteristics of the antenna, such as resonant frequency, radiation pattern, and radiation efficiency are investigated experimentally and numerically. The antenna's resonant frequency and radiation characteristics can be changed by using the PIN diode switch, and the radiation efficiency degrades when forward-bias is added to the diode. The degradation of the radiation efficiency is mainly caused by high forward-bias resistance, which indicates that it is necessary to use a PIN diode with low forward-bias resistance.
{"title":"Dual-mode patch antenna switched by PIN diode","authors":"Q. Chen, M. Kurahashi, K. Sawaya","doi":"10.1109/WCT.2003.1321463","DOIUrl":"https://doi.org/10.1109/WCT.2003.1321463","url":null,"abstract":"Since various wireless communication services are available, it is required to make a mobile terminal which can handle several such services. Therefore, it is necessary to design a multimode, multifrequency antenna which has different polarization and radiation patterns at each band; the switching of the resonant modes should be controlled electronically. We propose a dual-mode patch antenna where a PIN diode switch is used to change the resonant mode of the antenna. The basic structure of the antenna is a planar inverted F-shape antenna (PIFA) with a PIN diode at the open terminal of the patch. The PIN diode is switched by the DC bias which is provided at the RF feed. When the PIN diode is biased forward (ON), the antenna operates as a loop antenna, while when the PIN diode is biased backward (OFF), the antenna works as a PIFA. The characteristics of the antenna, such as resonant frequency, radiation pattern, and radiation efficiency are investigated experimentally and numerically. The antenna's resonant frequency and radiation characteristics can be changed by using the PIN diode switch, and the radiation efficiency degrades when forward-bias is added to the diode. The degradation of the radiation efficiency is mainly caused by high forward-bias resistance, which indicates that it is necessary to use a PIN diode with low forward-bias resistance.","PeriodicalId":6305,"journal":{"name":"2003 IEEE Topical Conference on Wireless Communication Technology","volume":"34 1","pages":"148-149"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73106589","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 : 2003-10-15DOI: 10.1109/WCT.2003.1321436
L. Larson
The rapid deployment of next generation communications systems - both wired and wireless on a world-wide basis creates a unique opportunity for the semiconductor industry. High-speed networks require massive computing power and analog and radiofrequency devices with wide dynamic range and bandwidth. The semiconductor technologies required to implement these systems are highlighted, with particular emphasis on the technologies required to meet the demands of mobile computing applications.
{"title":"Microwave device and circuit challenges for next generation wireless applications","authors":"L. Larson","doi":"10.1109/WCT.2003.1321436","DOIUrl":"https://doi.org/10.1109/WCT.2003.1321436","url":null,"abstract":"The rapid deployment of next generation communications systems - both wired and wireless on a world-wide basis creates a unique opportunity for the semiconductor industry. High-speed networks require massive computing power and analog and radiofrequency devices with wide dynamic range and bandwidth. The semiconductor technologies required to implement these systems are highlighted, with particular emphasis on the technologies required to meet the demands of mobile computing applications.","PeriodicalId":6305,"journal":{"name":"2003 IEEE Topical Conference on Wireless Communication Technology","volume":"150 1","pages":"74-77"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77586989","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 : 2003-10-15DOI: 10.1109/WCT.2003.1321422
S. Saghafi, F. Arfaei
We consider the correlation between equivalent gate and drain noise sources in the two-temperature model to demonstrate a better compatibility between measured noise parameters (y/sub opt/, R/sub n/ , F/sub min/) and the results from simulation. The originality of the contribution lies in considering correlation between external input and output equivalent noise temperatures ( T/sub in/ and T/sub out/) for a transistor. Danneville's model has been used with two additional constants (real and imaginary parts of correlation) which has a better agreement with measurements. A two stage MMIC compatible HEMT low noise amplifier at Ka-band, which could be used for local multipoint distribution systems (LMDS) and fixed satellite services (FSS), has been designed and the effect on its noise figure of noise sources' correlation has been considered. A low noise amplifier in Ka-band has been designed, and the proposed model applied to it. The results of the simulation have been compared in three cases.
{"title":"A new consideration of correlation between external noise sources in HEMT two-temperature model","authors":"S. Saghafi, F. Arfaei","doi":"10.1109/WCT.2003.1321422","DOIUrl":"https://doi.org/10.1109/WCT.2003.1321422","url":null,"abstract":"We consider the correlation between equivalent gate and drain noise sources in the two-temperature model to demonstrate a better compatibility between measured noise parameters (y/sub opt/, R/sub n/ , F/sub min/) and the results from simulation. The originality of the contribution lies in considering correlation between external input and output equivalent noise temperatures ( T/sub in/ and T/sub out/) for a transistor. Danneville's model has been used with two additional constants (real and imaginary parts of correlation) which has a better agreement with measurements. A two stage MMIC compatible HEMT low noise amplifier at Ka-band, which could be used for local multipoint distribution systems (LMDS) and fixed satellite services (FSS), has been designed and the effect on its noise figure of noise sources' correlation has been considered. A low noise amplifier in Ka-band has been designed, and the proposed model applied to it. The results of the simulation have been compared in three cases.","PeriodicalId":6305,"journal":{"name":"2003 IEEE Topical Conference on Wireless Communication Technology","volume":"960 1","pages":"14-15"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77587597","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 : 2003-10-15DOI: 10.1109/WCT.2003.1321488
Y. Tanaka, S. Watanabe, Y. Yamanaka, M. Taki, M. Takahashi
Maximum permissible exposure levels in terms of incident electromagnetic-field strength corresponding to ankle SAR of 25 W/kg, basic limits for extremities have been applied to a case where a human body has not been isolated from the ground plane. Because these limits were determined by considering worst-case exposure conditions, they can sometimes be too stringent. To relax the limit for nonisolated conditions, additional limits in terms of induced foot current, are introduced. The objective of this study is therefore to clarify the relationship between the ankle SAR and the induced foot-current i.e., the effective cross section.
{"title":"Study on effective area of ankle cross-section for estimation of ankle SAR with induced foot-current of a human body standing on ground plane","authors":"Y. Tanaka, S. Watanabe, Y. Yamanaka, M. Taki, M. Takahashi","doi":"10.1109/WCT.2003.1321488","DOIUrl":"https://doi.org/10.1109/WCT.2003.1321488","url":null,"abstract":"Maximum permissible exposure levels in terms of incident electromagnetic-field strength corresponding to ankle SAR of 25 W/kg, basic limits for extremities have been applied to a case where a human body has not been isolated from the ground plane. Because these limits were determined by considering worst-case exposure conditions, they can sometimes be too stringent. To relax the limit for nonisolated conditions, additional limits in terms of induced foot current, are introduced. The objective of this study is therefore to clarify the relationship between the ankle SAR and the induced foot-current i.e., the effective cross section.","PeriodicalId":6305,"journal":{"name":"2003 IEEE Topical Conference on Wireless Communication Technology","volume":"50 1","pages":"198-199"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75942590","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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