Pub Date : 2010-03-01DOI: 10.1109/SMIC.2010.5422941
F. Starzer, H. Forstner, C. Wagner, R. Feger, S. Scheiblhofer, A. Fischer, H. Jager, A. Stelzer
A novel radar frontend for 77 GHz mid-range-radar (MRR) and short-range-radar (SRR) applications is presented. The radar sensor makes use of a Colpitts oscillator, frequency multipliers, and a transceive (TRX) mixer. A single sensor contains up to four channels using antenna arrays for angular detection relative to the sensor. The characterization of the integrated circuit's parameters has been carried out using a two-channel sensor with waveguide (WG) transitions. A radar measurement scenario has been realized using a four-channel sensor with a differential antenna array. All sensors have been implemented on off-the-shelf printed circuit board (PCB) substrate.
{"title":"A novel 77-GHz radar frontend with 19-GHz signal distribution on RF-PCB substrate","authors":"F. Starzer, H. Forstner, C. Wagner, R. Feger, S. Scheiblhofer, A. Fischer, H. Jager, A. Stelzer","doi":"10.1109/SMIC.2010.5422941","DOIUrl":"https://doi.org/10.1109/SMIC.2010.5422941","url":null,"abstract":"A novel radar frontend for 77 GHz mid-range-radar (MRR) and short-range-radar (SRR) applications is presented. The radar sensor makes use of a Colpitts oscillator, frequency multipliers, and a transceive (TRX) mixer. A single sensor contains up to four channels using antenna arrays for angular detection relative to the sensor. The characterization of the integrated circuit's parameters has been carried out using a two-channel sensor with waveguide (WG) transitions. A radar measurement scenario has been realized using a four-channel sensor with a differential antenna array. All sensors have been implemented on off-the-shelf printed circuit board (PCB) substrate.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128132982","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.2010.5434166
L. Jin, X. Gu, Z. Hu
A new volume-based scheduling algorithm for user selection is proposed for a multiuser multiple-input and multiple-output downlink system based on block diagonalization precoding. The proposed algorithm has the advantage of the reduced computational complexity achieved by using the new volume-based user selection method that uses the product of the diagonal elements in the upper-triangular matrix obtained via Householder reduction procedure of QR factorization to the selected users channel matrix. The new algorithm provides the same sum-rate capacity in comparison with other user selection algorithms, such as semi-orthogonal user selection and capacity-based user selection algorithms, but with significantly reduced complexity.
{"title":"A novel volume-based scheduling scheme for multiuser multiple-input multiple-output downlink system","authors":"L. Jin, X. Gu, Z. Hu","doi":"10.1109/RWS.2010.5434166","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434166","url":null,"abstract":"A new volume-based scheduling algorithm for user selection is proposed for a multiuser multiple-input and multiple-output downlink system based on block diagonalization precoding. The proposed algorithm has the advantage of the reduced computational complexity achieved by using the new volume-based user selection method that uses the product of the diagonal elements in the upper-triangular matrix obtained via Householder reduction procedure of QR factorization to the selected users channel matrix. The new algorithm provides the same sum-rate capacity in comparison with other user selection algorithms, such as semi-orthogonal user selection and capacity-based user selection algorithms, but with significantly reduced complexity.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"54 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":"115298375","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.2010.5434206
D. Trinchero, R. Stefanelli, Manuel Ricardo Perez Cerquera
The interest in the exploitation of wireless sensor networks in dissipative media (other than the free space) is nowadays growing in importance, thanks to the identification of newer and newer fields of application. This paper introduces a methodology for the analysis of the geometrical parameters of the antenna. The proposed procedure takes into account the coupling mechanism with the surrounding medium, as well as the electromagnetic interaction with the electronic and metallic components of the sensor. In this way, the identification of the parameters can be carried out by an introduction of a simplified iterative pre-conditioned modeling procedure that avoids long running times typical of a complete full wave model. Results obtained for the analysis of mobile sensor networks floating in underground water conduits confirm the adequacy of the proposed method.
{"title":"Design and optimization of the electromagnetic front-end for wireless sensors floating in dissipative media","authors":"D. Trinchero, R. Stefanelli, Manuel Ricardo Perez Cerquera","doi":"10.1109/RWS.2010.5434206","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434206","url":null,"abstract":"The interest in the exploitation of wireless sensor networks in dissipative media (other than the free space) is nowadays growing in importance, thanks to the identification of newer and newer fields of application. This paper introduces a methodology for the analysis of the geometrical parameters of the antenna. The proposed procedure takes into account the coupling mechanism with the surrounding medium, as well as the electromagnetic interaction with the electronic and metallic components of the sensor. In this way, the identification of the parameters can be carried out by an introduction of a simplified iterative pre-conditioned modeling procedure that avoids long running times typical of a complete full wave model. Results obtained for the analysis of mobile sensor networks floating in underground water conduits confirm the adequacy of the proposed method.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"54 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":"115385644","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.2010.5434120
Kenji Suzuki, M. Ugajin, M. Harada
A 5th-order switched-capacitor (SC) complex filter is implemented in 0.2-µm CMOS technology. In order to reduce the die size and current consumption of the complex filter, a novel SC integrator is developed. The filter is centered at 24.8 kHz with bandwidth of 20.2 kHz. The Image channel is attenuated by more than 40 dB. The in-band 3rd order harmonic input intercept point (IIP3) is 15 dBm and the in-band output noise is 70 µVrms. The complex filter consumes 350 µA with a 2.0-V power supply. The die size of the fabricated filter is 0.578 mm2. Owing to the proposed SC integrator, the fabricated filter achieved 27% reduction in die size without any characteristic degradation, including noise performance, compared to the conventional equivalent.
{"title":"A 5th-order switched-capacitor complex filter for low-IF narrowband wireless receivers","authors":"Kenji Suzuki, M. Ugajin, M. Harada","doi":"10.1109/RWS.2010.5434120","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434120","url":null,"abstract":"A 5th-order switched-capacitor (SC) complex filter is implemented in 0.2-µm CMOS technology. In order to reduce the die size and current consumption of the complex filter, a novel SC integrator is developed. The filter is centered at 24.8 kHz with bandwidth of 20.2 kHz. The Image channel is attenuated by more than 40 dB. The in-band 3rd order harmonic input intercept point (IIP3) is 15 dBm and the in-band output noise is 70 µVrms. The complex filter consumes 350 µA with a 2.0-V power supply. The die size of the fabricated filter is 0.578 mm2. Owing to the proposed SC integrator, the fabricated filter achieved 27% reduction in die size without any characteristic degradation, including noise performance, compared to the conventional equivalent.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"52 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":"124925403","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.2010.5434143
Jangsu Kim, H. Ryu
Performance of multi-user SC-FDMA (single carrier-frequency division multiple access) system varies according to the user allocation and adaptive bit assignment to the subcarriers because each user experiences different channel characteristics. If any specific user suffers from poor channel characteristics in the conventional method of the distributed and localized user mapping, the total communication performance will be degraded. So, in this paper, we like to propose a user allocation method to improve the system performance in the frequency selective fading channel. We allocate users first who have best channel condition in comparison with all users to each subcarrier according to the channel state information. And we increase bandwidth efficiency by improving the modulation level to high order because most users have good channel condition through subcarrier allocation method. Therefore, we improve system performance like the BER performance and throughput effectively. Through the computer simulations, the performance of proposed system is analyzed and compared with existing method.
{"title":"Adaptive modulation for maximum throughput of multi-user SC-FDMA system in doubly selective channel","authors":"Jangsu Kim, H. Ryu","doi":"10.1109/RWS.2010.5434143","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434143","url":null,"abstract":"Performance of multi-user SC-FDMA (single carrier-frequency division multiple access) system varies according to the user allocation and adaptive bit assignment to the subcarriers because each user experiences different channel characteristics. If any specific user suffers from poor channel characteristics in the conventional method of the distributed and localized user mapping, the total communication performance will be degraded. So, in this paper, we like to propose a user allocation method to improve the system performance in the frequency selective fading channel. We allocate users first who have best channel condition in comparison with all users to each subcarrier according to the channel state information. And we increase bandwidth efficiency by improving the modulation level to high order because most users have good channel condition through subcarrier allocation method. Therefore, we improve system performance like the BER performance and throughput effectively. Through the computer simulations, the performance of proposed system is analyzed and compared with existing method.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"29 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":"123722952","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.2010.5434211
Kiran Anna, M. Bassiouni
Several analytical models were proposed in the literature to provide throughput performance evaluation of the 802.11 MAC protocol. The performance parameter “Saturation Throughput” is defined as the limit reached by the system throughput as the offered system load increases. This parameter is evaluated under overloaded conditions, i.e., the transmission queue of each station is assumed to be always nonempty. Our extensive simulation results obtained using NS2 for the p-persistent 802.11 MAC protocol show different behavior. The p-persistent throughput linearly increases with the load to a certain point and reaches a constant saturation throughput. Unlike the standard 802.11, there is no peak value followed by a drop in the throughput of the p-persistent 802.11. Our simulation results clearly show that the saturation throughput is often attained without 100% contention among all the nodes. This is an important observation that contradicts the assumption used in the literature for the analytical modeling of the 802.11 MAC protocol. We are currently using this observation in the design of the load estimation component of the admission control mechanism for WLANS.
{"title":"Analysis of the saturation throughput and node contention levels in the 802.11 MAC protocol","authors":"Kiran Anna, M. Bassiouni","doi":"10.1109/RWS.2010.5434211","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434211","url":null,"abstract":"Several analytical models were proposed in the literature to provide throughput performance evaluation of the 802.11 MAC protocol. The performance parameter “Saturation Throughput” is defined as the limit reached by the system throughput as the offered system load increases. This parameter is evaluated under overloaded conditions, i.e., the transmission queue of each station is assumed to be always nonempty. Our extensive simulation results obtained using NS2 for the p-persistent 802.11 MAC protocol show different behavior. The p-persistent throughput linearly increases with the load to a certain point and reaches a constant saturation throughput. Unlike the standard 802.11, there is no peak value followed by a drop in the throughput of the p-persistent 802.11. Our simulation results clearly show that the saturation throughput is often attained without 100% contention among all the nodes. This is an important observation that contradicts the assumption used in the literature for the analytical modeling of the 802.11 MAC protocol. We are currently using this observation in the design of the load estimation component of the admission control mechanism for WLANS.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"13 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":"130519343","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.2010.5434142
S. Bassam, M. Helaoui, F. Ghannouchi
This paper investigates the effect of nonlinear crosstalk on the overall performance of the MIMO transmitter. It proposes a linearization technique to correct for the effect of crosstalk and hence enhance the BER performance of the MIMO system. Recently it was shown that in the presence of nonlinear crosstalk, the conventional digital predistortion technique is unable to linearize the transmitter, which leads to significant degradation in bit-error-rate of the MIMO system. In this regard, a new digital predistortion method known as crossover digital predistorter (CO-DPD) is developed and implemented. The simulation results show that the CO-DPD model is able to both compensate for the transmitter nonlinearity and achieve BER results close to the ideal MIMO transmitter.
{"title":"BER performance assessment of linearized MIMO transmitters in presence of RF crosstalk","authors":"S. Bassam, M. Helaoui, F. Ghannouchi","doi":"10.1109/RWS.2010.5434142","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434142","url":null,"abstract":"This paper investigates the effect of nonlinear crosstalk on the overall performance of the MIMO transmitter. It proposes a linearization technique to correct for the effect of crosstalk and hence enhance the BER performance of the MIMO system. Recently it was shown that in the presence of nonlinear crosstalk, the conventional digital predistortion technique is unable to linearize the transmitter, which leads to significant degradation in bit-error-rate of the MIMO system. In this regard, a new digital predistortion method known as crossover digital predistorter (CO-DPD) is developed and implemented. The simulation results show that the CO-DPD model is able to both compensate for the transmitter nonlinearity and achieve BER results close to the ideal MIMO transmitter.","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":"130630821","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.2010.5434270
Sukhoon Oh, C. A. Roopnariane, M. Tofighi, C. Collins
We describe an MRI-based method for mapping temperature and specific absorption rate (SAR) using a solenoid coil and a birdcage coil for heating and imaging of a weakly conductive dielectric sample, respectively. The accuracy and the quality of SAR/temperature mapping are enhanced by separating the heating and imaging RF coils. 50 W of RF power is applied to the solenoid coil to heat the conductive agar-gel phantom for 120 sec. Maps of temperature increase were acquired with an MRI-based method. The MR-based measurements were in good agreement with fiber optic measurements. Finally, the dual-coil heating system was simulated using the finite difference time domain (FDTD) method. The distribution of numerically-calculated and experimentally-acquired SAR were also in good agreement.
{"title":"MRI-based temperature and SAR mapping with a new dual-coil solenoid/birdcage heating/measurement system","authors":"Sukhoon Oh, C. A. Roopnariane, M. Tofighi, C. Collins","doi":"10.1109/RWS.2010.5434270","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434270","url":null,"abstract":"We describe an MRI-based method for mapping temperature and specific absorption rate (SAR) using a solenoid coil and a birdcage coil for heating and imaging of a weakly conductive dielectric sample, respectively. The accuracy and the quality of SAR/temperature mapping are enhanced by separating the heating and imaging RF coils. 50 W of RF power is applied to the solenoid coil to heat the conductive agar-gel phantom for 120 sec. Maps of temperature increase were acquired with an MRI-based method. The MR-based measurements were in good agreement with fiber optic measurements. Finally, the dual-coil heating system was simulated using the finite difference time domain (FDTD) method. The distribution of numerically-calculated and experimentally-acquired SAR were also in good agreement.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"20 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":"130671670","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.2010.5434252
Lin Cheng, Rahul Shakya
Vehicle Ad Hoc Networks (VANET) may exhibit different behavior depending on traffic and the time of day. Consider the potential worm attack in time-variant VANET channel, we use measured vehicle traffic data to model VANET worm spreading and patching. We also discuss the contributing factors for the differences observed.
{"title":"VANET worm spreading from traffic modeling","authors":"Lin Cheng, Rahul Shakya","doi":"10.1109/RWS.2010.5434252","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434252","url":null,"abstract":"Vehicle Ad Hoc Networks (VANET) may exhibit different behavior depending on traffic and the time of day. Consider the potential worm attack in time-variant VANET channel, we use measured vehicle traffic data to model VANET worm spreading and patching. We also discuss the contributing factors for the differences observed.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"14 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":"123603637","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.2010.5434265
M. Naeem, Daniel C. Lee
In this paper, we present a real-time low-complexity joint transmit and receive antenna selection (JTRAS) algorithm. The computational complexity of finding an optimal JTRAS by exhaustive search grows exponentially with the number of transmit and receive antennas. The proposed Estimation of Distribution Algorithm (EDA) is resorts to probabilistic distribution learning evolutionary computation. EDA updates its chosen population at each iteration on the basis of the probability distribution learned from the population of superior candidate solutions chosen at the previous iterations. The proposed EDA has a low computational complexity and can find a nearly optimal solution in real time. Beyond applying the general EDA to JTRAS, we also present a specific improvement to EDA, which reduces computation time by generating cyclic shifted initial population. The proposed EDA for JTRAS has a low computational complexity, and its effectiveness is verified through simulation results.
{"title":"Joint transmit and receive antenna selection using a probabilistic distribution learning algorithm in MIMO systems","authors":"M. Naeem, Daniel C. Lee","doi":"10.1109/RWS.2010.5434265","DOIUrl":"https://doi.org/10.1109/RWS.2010.5434265","url":null,"abstract":"In this paper, we present a real-time low-complexity joint transmit and receive antenna selection (JTRAS) algorithm. The computational complexity of finding an optimal JTRAS by exhaustive search grows exponentially with the number of transmit and receive antennas. The proposed Estimation of Distribution Algorithm (EDA) is resorts to probabilistic distribution learning evolutionary computation. EDA updates its chosen population at each iteration on the basis of the probability distribution learned from the population of superior candidate solutions chosen at the previous iterations. The proposed EDA has a low computational complexity and can find a nearly optimal solution in real time. Beyond applying the general EDA to JTRAS, we also present a specific improvement to EDA, which reduces computation time by generating cyclic shifted initial population. The proposed EDA for JTRAS has a low computational complexity, and its effectiveness is verified through simulation results.","PeriodicalId":334671,"journal":{"name":"2010 IEEE Radio and Wireless Symposium (RWS)","volume":"60 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":"116251923","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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