Pub Date : 2010-01-10DOI: 10.1109/RWS.2010.5434254
Lin Cheng, Ankit Saraf
Deep understanding of the Doppler spectrum components is an indispensable part to alleviate fading impairments in Vehicle Ad Hoc Networks (VANET). This paper presents a method to simulate the different Doppler components, incorporating vehicle speeds, environment and traffic. We hope this can serve as a building block for realistic simulation, and can be used to improve the reliability and robustness of wireless communications in VANET systems.
{"title":"Simulating Doppler components in the vehicle-to-vehicle communication channel","authors":"Lin Cheng, Ankit Saraf","doi":"10.1109/RWS.2010.5434254","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434254","url":null,"abstract":"Deep understanding of the Doppler spectrum components is an indispensable part to alleviate fading impairments in Vehicle Ad Hoc Networks (VANET). This paper presents a method to simulate the different Doppler components, incorporating vehicle speeds, environment and traffic. We hope this can serve as a building block for realistic simulation, and can be used to improve the reliability and robustness of wireless communications in VANET systems.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122183269","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 : 2010-01-10DOI: 10.1109/RWS.2010.5434242
A. Khwaja, P. Miranda, V. Mistry, C. Hinton, S. Garg, A. Sharma, A. Daryoush
4×4 ring array antennas are combined with commercially available and custom designed RF components to realize a base station operating for channel #1 of UWB communications. The 4 transmitters and receivers modules are developed using LNA, PA, buffer amplifiers, custom designed single and dual GCM mixers, and differential BPF and LPF. The GCM mixer is driven by a StLO poly-phase board that is realized using stable LO, PA, custom designed poly-phase circuit and 1∶2 power divider/Baluns at 3.158GHz.
{"title":"Ultra wide band system realization for 4×4 MIMO test bed","authors":"A. Khwaja, P. Miranda, V. Mistry, C. Hinton, S. Garg, A. Sharma, A. Daryoush","doi":"10.1109/RWS.2010.5434242","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434242","url":null,"abstract":"4×4 ring array antennas are combined with commercially available and custom designed RF components to realize a base station operating for channel #1 of UWB communications. The 4 transmitters and receivers modules are developed using LNA, PA, buffer amplifiers, custom designed single and dual GCM mixers, and differential BPF and LPF. The GCM mixer is driven by a StLO poly-phase board that is realized using stable LO, PA, custom designed poly-phase circuit and 1∶2 power divider/Baluns at 3.158GHz.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122785329","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 : 2010-01-10DOI: 10.1109/RWS.2010.5434124
S. Luo, Z. Chen, N. Polu, M. Murillo
Channel modeling is very important for wireless system designs, especially in a radio harsh environment. The impulse response is a key quantity that characterizes the time-domain properties of a RF channel. One of the conventional ways to obtain a channel impulse response is to measure the channel frequency-domain transfer function with a vector network analyzer and then convert the measured transfer function into its time-domain impulse response through the inverse Fourier transform. However, because the transfer function can practically be measured only within a finite frequency band, the obtained impulse response is often not causal and not very accurate with high resolutions. In this paper, we propose a Hilbert transform based iterative method to expand and extrapolate the transfer function beyond its measured frequency band and thus s highly-resolved causal impulse response of a RF channel can be obtained.
{"title":"Iterative method for extracting impulse response of a RF channel with its band-limited transfer function","authors":"S. Luo, Z. Chen, N. Polu, M. Murillo","doi":"10.1109/RWS.2010.5434124","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434124","url":null,"abstract":"Channel modeling is very important for wireless system designs, especially in a radio harsh environment. The impulse response is a key quantity that characterizes the time-domain properties of a RF channel. One of the conventional ways to obtain a channel impulse response is to measure the channel frequency-domain transfer function with a vector network analyzer and then convert the measured transfer function into its time-domain impulse response through the inverse Fourier transform. However, because the transfer function can practically be measured only within a finite frequency band, the obtained impulse response is often not causal and not very accurate with high resolutions. In this paper, we propose a Hilbert transform based iterative method to expand and extrapolate the transfer function beyond its measured frequency band and thus s highly-resolved causal impulse response of a RF channel can be obtained.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132692798","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 : 2010-01-10DOI: 10.1109/RWS.2010.5434141
K. S. Ryu, A. Kishk
A new dielectric resonator antenna (DRA) for ultra wideband applications is presented. This UWB antenna has excellent Omni-directional radiation patterns over the entire band with the low cross-polarization. The antenna is composed of a solid DR inserted in a substrate, which is excited by a coplanar waveguide feed (CPW).
{"title":"UWB dielectric resonator antenna with low cross-polarization","authors":"K. S. Ryu, A. Kishk","doi":"10.1109/RWS.2010.5434141","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434141","url":null,"abstract":"A new dielectric resonator antenna (DRA) for ultra wideband applications is presented. This UWB antenna has excellent Omni-directional radiation patterns over the entire band with the low cross-polarization. The antenna is composed of a solid DR inserted in a substrate, which is excited by a coplanar waveguide feed (CPW).","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132047983","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 : 2010-01-10DOI: 10.1109/RWS.2010.5434225
W. Hamdane, A. Kouki, F. Gagnon
This paper proposes a new digital implementation of the Chireix combiner when excited with idea sources. It is shown that proper baseband phase predistorsion can be made equivalent a physical combiner with optimal impedance and prescribed stubs. This technique can be used with a new stubless combiner design or retrofitted to an existing combiner with non-zero stubs. Several theoretical and experimental validations of the proposed technique are presented showing excellent agreement between theory, simulations and measurements of the digital and physical implementation of the Chireix combiner. An application of this technique for varying MQAM modulations confirms the suitability of the proposed technique to the adaptive modulation environment and its excellent ability to allow simultaneous optimization of combining efficiency.
{"title":"An equivalent digital implementation of Chireix combiners under ideal source excitation","authors":"W. Hamdane, A. Kouki, F. Gagnon","doi":"10.1109/RWS.2010.5434225","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434225","url":null,"abstract":"This paper proposes a new digital implementation of the Chireix combiner when excited with idea sources. It is shown that proper baseband phase predistorsion can be made equivalent a physical combiner with optimal impedance and prescribed stubs. This technique can be used with a new stubless combiner design or retrofitted to an existing combiner with non-zero stubs. Several theoretical and experimental validations of the proposed technique are presented showing excellent agreement between theory, simulations and measurements of the digital and physical implementation of the Chireix combiner. An application of this technique for varying MQAM modulations confirms the suitability of the proposed technique to the adaptive modulation environment and its excellent ability to allow simultaneous optimization of combining efficiency.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132168968","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 : 2010-01-10DOI: 10.1109/RWS.2010.5434229
Maurizio A. Nanni, S. Basagni
This paper presents a new protocol for the formation and maintenance of a backbone from the nodes of an ad hoc network where all the nodes are mobile. The new protocol is defined and its performance evaluated with respect to metrics such as its size, that favors scalability, its connectivity in time, which allows protocols to run efficiently, robustness and route length. Via ns2-based simulation experiments we demonstrate the effectiveness of proposed protocol for mobile ad hoc backbones in achieving a manageable size of the produced backbone, a connectivity in time which is maintained for the greatest majority of the simulation time, considerable robustness even at lower densities and route lengths that are negligibly bigger that the length of the routes in the flat network topology.
{"title":"Mobile ad hoc backbones: Formation and maintenance","authors":"Maurizio A. Nanni, S. Basagni","doi":"10.1109/RWS.2010.5434229","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434229","url":null,"abstract":"This paper presents a new protocol for the formation and maintenance of a backbone from the nodes of an ad hoc network where all the nodes are mobile. The new protocol is defined and its performance evaluated with respect to metrics such as its size, that favors scalability, its connectivity in time, which allows protocols to run efficiently, robustness and route length. Via ns2-based simulation experiments we demonstrate the effectiveness of proposed protocol for mobile ad hoc backbones in achieving a manageable size of the produced backbone, a connectivity in time which is maintained for the greatest majority of the simulation time, considerable robustness even at lower densities and route lengths that are negligibly bigger that the length of the routes in the flat network topology.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132234329","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 : 2010-01-10DOI: 10.1109/RWS.2010.5434137
J. Staudinger, Jean-Christophe Nanan, J. Wood
This paper presents a novel technique of adapting the generalized Volterra series behavioral model to describe, with improved accuracy, power amplifiers targeting cellular infrastructure applications. The generalized Volterra series is reformulated with respect to the discrete time domain to allow impendent specification of memory depth for each kernel. A memory fading concept is then adopted to align memory depth to increasing kernel order. The number of Volterra coefficients needed to represent a strong PA non-linearity are significantly reduced (to a manageable level), while retaining certain high order kernels essential for realizing exceptional model fidelity. Results show model residuals better than -60 dBc for single- and two-carrier WCDMA signals when applied to a 350W LDMOS Doherty power amplifier circuit.
{"title":"Memory fading Volterra series model for high power infrastructure amplifiers","authors":"J. Staudinger, Jean-Christophe Nanan, J. Wood","doi":"10.1109/RWS.2010.5434137","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434137","url":null,"abstract":"This paper presents a novel technique of adapting the generalized Volterra series behavioral model to describe, with improved accuracy, power amplifiers targeting cellular infrastructure applications. The generalized Volterra series is reformulated with respect to the discrete time domain to allow impendent specification of memory depth for each kernel. A memory fading concept is then adopted to align memory depth to increasing kernel order. The number of Volterra coefficients needed to represent a strong PA non-linearity are significantly reduced (to a manageable level), while retaining certain high order kernels essential for realizing exceptional model fidelity. Results show model residuals better than -60 dBc for single- and two-carrier WCDMA signals when applied to a 350W LDMOS Doherty power amplifier circuit.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131128874","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 : 2010-01-10DOI: 10.1109/RWS.2010.5434113
M. Ubostad, M. Olavsbråten
Adjusting the biasing- and loading conditions in a power amplifier affects the linearity and efficiency of the PA. If an accurate nonlinear model for the transistor does not exist, load-pull measurements are necessary for a high-performance PA design. In this work load-pull measurements are performed under different biasing conditions in order to utilize the fully potential of the transistor in the PA. Two different linearity criteria, one strict at -40 dB ACPR and one more relaxed at -33 dB for a 16 QAM signal, should be met by the PA, and the best bias point and load are found for these criteria from load pull measurements with single tone and digitally modulated signal. The impact on the results when linearizing the PA with DPD are also investigated. The measurements on a 1 W pHEMT transistor show that by utilizing sweet spots when biasing in deep class AB the most output power and PAE could be achieved with an ACPR level of -33 dB. With an ACPR limit of -40 dB biasing toward class A maximizes the output power. At this criterion there is much to gain by performing load pull measurements with a digitally modulated signal. When applying DPD the output power is almost independent of the biasing conditions for both linearity criteria and the load should be chosen to maximize output power at 1 dB compression.
调整功率放大器的偏置和负载条件会影响放大器的线性度和效率。如果晶体管的精确非线性模型不存在，则负载-拉力测量对于高性能PA设计是必要的。在这项工作中，负载-拉力测量是在不同的偏置条件下进行的，以便充分利用放大器中晶体管的潜力。扩音器应满足两个不同的线性度标准，一个是严格的-40 dB ACPR标准，另一个是宽松的-33 dB标准，适用于16 QAM信号。通过单音和数字调制信号的负载拉力测量，找到了这些标准的最佳偏置点和负载。本文还研究了PA与DPD线性化对结果的影响。在1 W pHEMT晶体管上的测量表明，当偏置在深AB类时，利用甜点可以在-33 dB的ACPR电平下实现最大输出功率和PAE。ACPR限制为-40 dB，偏置A类可使输出功率最大化。在这个标准下，用数字调制信号进行负载拉力测量有很大的增益。当应用DPD时，输出功率几乎与线性标准和负载的偏置条件无关，应选择在1 dB压缩时最大输出功率的负载。
{"title":"Linearity performance of an RF power amplifier under different bias-and load conditions with and without DPD","authors":"M. Ubostad, M. Olavsbråten","doi":"10.1109/RWS.2010.5434113","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434113","url":null,"abstract":"Adjusting the biasing- and loading conditions in a power amplifier affects the linearity and efficiency of the PA. If an accurate nonlinear model for the transistor does not exist, load-pull measurements are necessary for a high-performance PA design. In this work load-pull measurements are performed under different biasing conditions in order to utilize the fully potential of the transistor in the PA. Two different linearity criteria, one strict at -40 dB ACPR and one more relaxed at -33 dB for a 16 QAM signal, should be met by the PA, and the best bias point and load are found for these criteria from load pull measurements with single tone and digitally modulated signal. The impact on the results when linearizing the PA with DPD are also investigated. The measurements on a 1 W pHEMT transistor show that by utilizing sweet spots when biasing in deep class AB the most output power and PAE could be achieved with an ACPR level of -33 dB. With an ACPR limit of -40 dB biasing toward class A maximizes the output power. At this criterion there is much to gain by performing load pull measurements with a digitally modulated signal. When applying DPD the output power is almost independent of the biasing conditions for both linearity criteria and the load should be chosen to maximize output power at 1 dB compression.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128112229","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 : 2010-01-10DOI: 10.1109/RWS.2010.5434198
K. Ono, K. Ohta, I. Matsunami, A. Kajiwara
Delay profile of wideband indoor channel fluctuates for a physical change such as intruder. This paper investigates a human body detection using the wideband radio at 2.4GHz (ISMband) in order to protect a house, not a room, because the radio with high range resolution can penetrate into the inner walls and also the reflected paths from human body are discriminated in time domain. The usefulness is experimentally investigated under a scenario which someone intrudes into a typical house with four rooms and walks around.
{"title":"Home security sensor using 2.4GHz ISM band","authors":"K. Ono, K. Ohta, I. Matsunami, A. Kajiwara","doi":"10.1109/RWS.2010.5434198","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434198","url":null,"abstract":"Delay profile of wideband indoor channel fluctuates for a physical change such as intruder. This paper investigates a human body detection using the wideband radio at 2.4GHz (ISMband) in order to protect a house, not a room, because the radio with high range resolution can penetrate into the inner walls and also the reflected paths from human body are discriminated in time domain. The usefulness is experimentally investigated under a scenario which someone intrudes into a typical house with four rooms and walks around.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129246805","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 : 2010-01-10DOI: 10.1109/RWS.2010.5434192
S. Mukherjee
A low cost, fast yet highly accurate method for determining liquid level inside small containers is described. The non-invasive technique can easily resolve sub-1% levels in vials containing a few ml or less of liquid and potentially be an order of magnitude more accurate than capacitive level sensors. The vial is placed inside an electrically conducting holder to guide a radio-frequency wave inside the vial. The holder-vial guide acts like an open circuited transmission line whose reflection coefficient is nominally unity but phase angle is a function of the liquid level. By performing a vector measurement of the reflection coefficient, it is possible to achieve sub-wavelength resolution and therefore measure the level highly accurately. An intentional impedance mismatch between the holder-vial guide and the measurement system can be used enhance the sensitivity to level variations, the optimum sensitivity occurring at multiples of quarter wavelength. The implementation details in the form of a reflectometer and results from an actual level measurement are presented.
{"title":"Non-invasive measurement of liquid content inside a small vial","authors":"S. Mukherjee","doi":"10.1109/RWS.2010.5434192","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434192","url":null,"abstract":"A low cost, fast yet highly accurate method for determining liquid level inside small containers is described. The non-invasive technique can easily resolve sub-1% levels in vials containing a few ml or less of liquid and potentially be an order of magnitude more accurate than capacitive level sensors. The vial is placed inside an electrically conducting holder to guide a radio-frequency wave inside the vial. The holder-vial guide acts like an open circuited transmission line whose reflection coefficient is nominally unity but phase angle is a function of the liquid level. By performing a vector measurement of the reflection coefficient, it is possible to achieve sub-wavelength resolution and therefore measure the level highly accurately. An intentional impedance mismatch between the holder-vial guide and the measurement system can be used enhance the sensitivity to level variations, the optimum sensitivity occurring at multiples of quarter wavelength. The implementation details in the form of a reflectometer and results from an actual level measurement are presented.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"205 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123036662","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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