Pub Date : 2019-06-27DOI: 10.1109/VTCSpring.2019.8746717
Henry Schulten, M. Kuhn, R. Heyn, Gregor Dumphart, F. Troesch, A. Wittneben
Due to their low complexity, RSSI-based solutions for indoor localization have become increasingly popular in recent years despite lacking the accuracy of more sophisticated localization solutions. One of the main reasons for this lack of accuracy is the highly fluctuating nature of RSSI values as a result of indoor channel characteristics, hardware imperfections and varying antenna radiation patterns. In this paper, we thus critically analyze the log- normal path loss model and its validity with the focus on indoor localization. We show how chip antennas of typical consumer devices affect the RSSI measurements and clarify in what manner this effect can be incorporated into the log-normal model. In this process, we are also able to quantify the impact of small-scale fading and diversity on RSSI-based distance estimation. We furthermore propose a novel calibration scheme that estimates path loss exponents based on a simple training walk and outperforms linear regression in all our use cases. At last, we combine our findings in an implementation of an indoor localization system for a 14×3 m office corridor. On average, our measurements yield a significantly decreased position RMSE of 1.36 m, which compares to the Cramer- Rao lower bound on the position RMSE of 0.71 m in this environment.
{"title":"On the Crucial Impact of Antennas and Diversity on BLE RSSI-Based Indoor Localization","authors":"Henry Schulten, M. Kuhn, R. Heyn, Gregor Dumphart, F. Troesch, A. Wittneben","doi":"10.1109/VTCSpring.2019.8746717","DOIUrl":"https://doi.org/10.1109/VTCSpring.2019.8746717","url":null,"abstract":"Due to their low complexity, RSSI-based solutions for indoor localization have become increasingly popular in recent years despite lacking the accuracy of more sophisticated localization solutions. One of the main reasons for this lack of accuracy is the highly fluctuating nature of RSSI values as a result of indoor channel characteristics, hardware imperfections and varying antenna radiation patterns. In this paper, we thus critically analyze the log- normal path loss model and its validity with the focus on indoor localization. We show how chip antennas of typical consumer devices affect the RSSI measurements and clarify in what manner this effect can be incorporated into the log-normal model. In this process, we are also able to quantify the impact of small-scale fading and diversity on RSSI-based distance estimation. We furthermore propose a novel calibration scheme that estimates path loss exponents based on a simple training walk and outperforms linear regression in all our use cases. At last, we combine our findings in an implementation of an indoor localization system for a 14×3 m office corridor. On average, our measurements yield a significantly decreased position RMSE of 1.36 m, which compares to the Cramer- Rao lower bound on the position RMSE of 0.71 m in this environment.","PeriodicalId":134773,"journal":{"name":"2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116603989","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 : 2019-06-27DOI: 10.1109/VTCSpring.2019.8746464
Anwesha Das, Gijs Dubbelman
In this work, we research and evaluate incremental hopping-window pose-graph fusion strategies for vehicle localization. Pose-graphs can model multiple absolute and relative vehicle localization sensors, and can be optimized using non-linear techniques. We focus on the performance of incremental hopping-window optimization for on- line usage in vehicles and compare it with global off-line optimization. Our evaluation is based on 180 Km long vehicle trajectories that are recorded in highway, urban, and rural areas, and that are accompanied with post-processed Real Time Kinematic GNSS as ground truth. The results exhibit a 17% reduction in the error's standard deviation and a significant reduction in GNSS outliers when compared with automotive-grade GNSS receivers. The incremental hopping-window pose- graph optimization bounds the computation cost, when compared to global pose-graph fusion, which increases linearly with the size of the pose- graph, whereas the difference in accuracy is only 1%. This allows real-time usage of non-linear pose-graph fusion for vehicle localization.
{"title":"Incremental Hopping-Window Pose-Graph Fusion for Real-Time Vehicle Localization","authors":"Anwesha Das, Gijs Dubbelman","doi":"10.1109/VTCSpring.2019.8746464","DOIUrl":"https://doi.org/10.1109/VTCSpring.2019.8746464","url":null,"abstract":"In this work, we research and evaluate incremental hopping-window pose-graph fusion strategies for vehicle localization. Pose-graphs can model multiple absolute and relative vehicle localization sensors, and can be optimized using non-linear techniques. We focus on the performance of incremental hopping-window optimization for on- line usage in vehicles and compare it with global off-line optimization. Our evaluation is based on 180 Km long vehicle trajectories that are recorded in highway, urban, and rural areas, and that are accompanied with post-processed Real Time Kinematic GNSS as ground truth. The results exhibit a 17% reduction in the error's standard deviation and a significant reduction in GNSS outliers when compared with automotive-grade GNSS receivers. The incremental hopping-window pose- graph optimization bounds the computation cost, when compared to global pose-graph fusion, which increases linearly with the size of the pose- graph, whereas the difference in accuracy is only 1%. This allows real-time usage of non-linear pose-graph fusion for vehicle localization.","PeriodicalId":134773,"journal":{"name":"2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131786838","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 : 2019-06-27DOI: 10.1109/VTCSpring.2019.8746465
R. Heyn, M. Kuhn, Henry Schulten, Gregor Dumphart, Janick Zwyssig, F. Troesch, A. Wittneben
The Received Signal Strength Indicator (RSSI) of Bluetooth Low Energy (BLE) is a popular means for indoor user localization and tracking as it reflects the transmitter-receiver distance and is readily available in all current smartphones. Since fading, shadowing and antenna patterns cause severe RSSI fluctuations, many RSSI-based localization systems use fingerprinting instead of parameter estimation based on a channel model (e.g. trilateration from distance estimates). Fingerprinting however requires a large effort for training data acquisition and frequent updates in dynamic environments. In this paper we focus on wireless access control with BLE. We demonstrate that a practical implementation of such a tracking system can meet the typical demands of generic access control problems with low- complexity parameter estimation techniques, namely trilateration and optional Kalman filtering. Thereby, satisfactory accuracy is enabled by diversity (averaging in space, time and frequency), calibration and appropriate observation space modeling. We find that including the RSSI directly in the observation space renders trilateration obsolete, which reduces complexity even further.
{"title":"User Tracking for Access Control with Bluetooth Low Energy","authors":"R. Heyn, M. Kuhn, Henry Schulten, Gregor Dumphart, Janick Zwyssig, F. Troesch, A. Wittneben","doi":"10.1109/VTCSpring.2019.8746465","DOIUrl":"https://doi.org/10.1109/VTCSpring.2019.8746465","url":null,"abstract":"The Received Signal Strength Indicator (RSSI) of Bluetooth Low Energy (BLE) is a popular means for indoor user localization and tracking as it reflects the transmitter-receiver distance and is readily available in all current smartphones. Since fading, shadowing and antenna patterns cause severe RSSI fluctuations, many RSSI-based localization systems use fingerprinting instead of parameter estimation based on a channel model (e.g. trilateration from distance estimates). Fingerprinting however requires a large effort for training data acquisition and frequent updates in dynamic environments. In this paper we focus on wireless access control with BLE. We demonstrate that a practical implementation of such a tracking system can meet the typical demands of generic access control problems with low- complexity parameter estimation techniques, namely trilateration and optional Kalman filtering. Thereby, satisfactory accuracy is enabled by diversity (averaging in space, time and frequency), calibration and appropriate observation space modeling. We find that including the RSSI directly in the observation space renders trilateration obsolete, which reduces complexity even further.","PeriodicalId":134773,"journal":{"name":"2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131378432","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 : 2019-06-27DOI: 10.1109/VTCSpring.2019.8746589
Renato B. Abreu, Thomas H. Jacobsen, Gilberto Berardinelli, K. Pedersen, N. Mahmood, I. Kovács, P. Mogensen
5G networks should support heterogeneous services with an efficient usage of the radio resources, while meeting the distinct requirements of each service class. We consider the problem of multiplexing enhanced mobile broadband (eMBB) traffic, and grant-free ultra-reliable low-latency communications (URLLC) in uplink. Two multiplexing options are considered; either eMBB and grant-free URLLC are transmitted in separate frequency bands to avoid their mutual interference, or both traffic share the available bandwidth leading to overlaying transmissions. This work presents an approach to evaluate the supported loads for URLLC and eMBB in different operation regimes. Minimum mean square error receivers with and without successive interference cancellation (SIC) are considered in Rayleigh fading channels. The outage probability is derived and the achievable transmission rates are obtained based on that. The analysis with 5G new radio assumptions shows that overlaying is mostly beneficial when SIC is employed in medium to high SNR scenarios or, in some cases, with low URLLC load. Otherwise, the use of separate bands supports higher loads for both services simultaneously. Practical insights based on the approach are discussed.
{"title":"On the Multiplexing of Broadband Traffic and Grant-Free Ultra-Reliable Communication in Uplink","authors":"Renato B. Abreu, Thomas H. Jacobsen, Gilberto Berardinelli, K. Pedersen, N. Mahmood, I. Kovács, P. Mogensen","doi":"10.1109/VTCSpring.2019.8746589","DOIUrl":"https://doi.org/10.1109/VTCSpring.2019.8746589","url":null,"abstract":"5G networks should support heterogeneous services with an efficient usage of the radio resources, while meeting the distinct requirements of each service class. We consider the problem of multiplexing enhanced mobile broadband (eMBB) traffic, and grant-free ultra-reliable low-latency communications (URLLC) in uplink. Two multiplexing options are considered; either eMBB and grant-free URLLC are transmitted in separate frequency bands to avoid their mutual interference, or both traffic share the available bandwidth leading to overlaying transmissions. This work presents an approach to evaluate the supported loads for URLLC and eMBB in different operation regimes. Minimum mean square error receivers with and without successive interference cancellation (SIC) are considered in Rayleigh fading channels. The outage probability is derived and the achievable transmission rates are obtained based on that. The analysis with 5G new radio assumptions shows that overlaying is mostly beneficial when SIC is employed in medium to high SNR scenarios or, in some cases, with low URLLC load. Otherwise, the use of separate bands supports higher loads for both services simultaneously. Practical insights based on the approach are discussed.","PeriodicalId":134773,"journal":{"name":"2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115252594","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 : 2019-06-27DOI: 10.1109/VTCSpring.2019.8746357
E. J. Khatib, Dereje Assefa Wassie, Gilberto Berardinelli, Ignacio Rodriguez, P. Mogensen
In the last years, wireless communications in industrial scenarios are becoming an increasingly important market. Some of these communications have tight reliability requirements, but harsh propagation conditions in industrial scenarios represent a major challenge. In this paper, multi-connectivity is explored as a solution for assuring high reliability in industrial scenarios. Several multi-connectivity techniques are compared, using real channel measurements from two factories. Multiconnectivity comes at the cost of a reduced throughput in the mobile broadband services on the same network. In this paper, this impact is quantified to assess for the cost of implementing multi-connectivity.
{"title":"Multi-Connectivity for Ultra-Reliable Communication in Industrial Scenarios","authors":"E. J. Khatib, Dereje Assefa Wassie, Gilberto Berardinelli, Ignacio Rodriguez, P. Mogensen","doi":"10.1109/VTCSpring.2019.8746357","DOIUrl":"https://doi.org/10.1109/VTCSpring.2019.8746357","url":null,"abstract":"In the last years, wireless communications in industrial scenarios are becoming an increasingly important market. Some of these communications have tight reliability requirements, but harsh propagation conditions in industrial scenarios represent a major challenge. In this paper, multi-connectivity is explored as a solution for assuring high reliability in industrial scenarios. Several multi-connectivity techniques are compared, using real channel measurements from two factories. Multiconnectivity comes at the cost of a reduced throughput in the mobile broadband services on the same network. In this paper, this impact is quantified to assess for the cost of implementing multi-connectivity.","PeriodicalId":134773,"journal":{"name":"2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130185945","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 : 2019-04-28DOI: 10.1109/VTCSPRING.2019.8746404
A. Auger, E. Lochin, N. Kuhn
How many times have ever asked yourself: "Can I trust my satellite experiments' outcome?". Performing experiments on real satellite system can either be (1) costly, as the radio resource may be scarce or (2) not possible, as you can hardly change the waveforms transmitted by the satellite platform. Moreover, assessing user applications QoE can hardly be done using only simulated environments while the QoS modeling of a satellite system can often lead to non-conclusive or ambiguous results. The aim of this paper is to bring out representative solutions allowing the networking community to drive consistent experiments using open-source tools. To this end, we compare Mininet and OpenSAND satellite emulator to a real satellite access provided by CNES. We consider VoIP traffic to analyze the trade-off between reliability of the results, ease of use and reproducibility of the experiments.
{"title":"Making Trustable Satellite Experiments: An Application to a VoIP Scenario","authors":"A. Auger, E. Lochin, N. Kuhn","doi":"10.1109/VTCSPRING.2019.8746404","DOIUrl":"https://doi.org/10.1109/VTCSPRING.2019.8746404","url":null,"abstract":"How many times have ever asked yourself: \"Can I trust my satellite experiments' outcome?\". Performing experiments on real satellite system can either be (1) costly, as the radio resource may be scarce or (2) not possible, as you can hardly change the waveforms transmitted by the satellite platform. Moreover, assessing user applications QoE can hardly be done using only simulated environments while the QoS modeling of a satellite system can often lead to non-conclusive or ambiguous results. The aim of this paper is to bring out representative solutions allowing the networking community to drive consistent experiments using open-source tools. To this end, we compare Mininet and OpenSAND satellite emulator to a real satellite access provided by CNES. We consider VoIP traffic to analyze the trade-off between reliability of the results, ease of use and reproducibility of the experiments.","PeriodicalId":134773,"journal":{"name":"2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134562721","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 : 2019-04-28DOI: 10.1109/VTCSpring.2019.8746306
Najett Neji, Tumader Mostfa, Y. Sebbane
In this paper, we develop an analytic methodology to determine the best technology to carry the communication between an Unmanned Aerial Vehicle (UAV) and a ground control station (GCS). We assume herein that the UAV is performing its mission under nominal conditions. For this, we identify some relevant criteria that cover most use-cases. We propose a multi-criteria analysis to determine the best technology to carry the radio- communication between the UAV and the GCS. In this work, we distinguish between the Control and Non- Payload Communication Channel (CNPC) and the Payload Channel. By studying two different missions, we emphasize that the technology assessment results depend on the use-case as well as the UAV scenario, and that for a same scenario the results for CNPC are different from the Payload communication. In this work, we are focused on the precise agriculture (PA) use-case, and the public safety (PS) use case. We present the assessment results in both Visual Line of Sight (VLOS), and Beyond Line of Sight (BVLOS) scenarios. The latter is very interesting because the communication UAV - GCS becomes of critical importance.
{"title":"Technology Assessment for Radio Communication between UAV and Ground: Qualitative Study and Applications","authors":"Najett Neji, Tumader Mostfa, Y. Sebbane","doi":"10.1109/VTCSpring.2019.8746306","DOIUrl":"https://doi.org/10.1109/VTCSpring.2019.8746306","url":null,"abstract":"In this paper, we develop an analytic methodology to determine the best technology to carry the communication between an Unmanned Aerial Vehicle (UAV) and a ground control station (GCS). We assume herein that the UAV is performing its mission under nominal conditions. For this, we identify some relevant criteria that cover most use-cases. We propose a multi-criteria analysis to determine the best technology to carry the radio- communication between the UAV and the GCS. In this work, we distinguish between the Control and Non- Payload Communication Channel (CNPC) and the Payload Channel. By studying two different missions, we emphasize that the technology assessment results depend on the use-case as well as the UAV scenario, and that for a same scenario the results for CNPC are different from the Payload communication. In this work, we are focused on the precise agriculture (PA) use-case, and the public safety (PS) use case. We present the assessment results in both Visual Line of Sight (VLOS), and Beyond Line of Sight (BVLOS) scenarios. The latter is very interesting because the communication UAV - GCS becomes of critical importance.","PeriodicalId":134773,"journal":{"name":"2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123768943","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 : 2019-04-28DOI: 10.1109/VTCSpring.2019.8746503
Kaoutar Abdelalim, Getachew Redieteab, S. Roblot, K. Amis
The expansion of wireless applications in dense environments raises many technical issues. The 802 standards need to adapt and enhance the network quality by developing new technologies. The block acknowledgment (BA) mechanism was introduced in the IEEE 802.11e standard to improve medium access control (MAC) efficiency. It requires the exchange of many control frames to establish a session with each user, which turns into an issue for networks in dense environments as it causes increased overhead and latency. This paper deals with the optimization of the BA session management procedure. We propose a modified block acknowledgment session control mechanism which reduces the overhead and latency compared to the original one.
{"title":"Adaptive Negotiation for Block Acknowledgment Session Management","authors":"Kaoutar Abdelalim, Getachew Redieteab, S. Roblot, K. Amis","doi":"10.1109/VTCSpring.2019.8746503","DOIUrl":"https://doi.org/10.1109/VTCSpring.2019.8746503","url":null,"abstract":"The expansion of wireless applications in dense environments raises many technical issues. The 802 standards need to adapt and enhance the network quality by developing new technologies. The block acknowledgment (BA) mechanism was introduced in the IEEE 802.11e standard to improve medium access control (MAC) efficiency. It requires the exchange of many control frames to establish a session with each user, which turns into an issue for networks in dense environments as it causes increased overhead and latency. This paper deals with the optimization of the BA session management procedure. We propose a modified block acknowledgment session control mechanism which reduces the overhead and latency compared to the original one.","PeriodicalId":134773,"journal":{"name":"2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131933748","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 : 2019-04-01DOI: 10.1109/VTCSpring.2019.8746441
Om Thakkar, Dhaval K. Patel, Y. Guan, Sumei Sun, Yoong Choon Chang, J. Lim
Dynamic Spectrum Access (DSA)/Cognitive Radio (CR) systems access the channel in an opportunistic, noninterfering manner with the primary network, thus being a promising approach to solve the problem of spectrum scarcity. Energy Detection, a spectrum sensing technique for DSA/CR systems, is widely used for blind sensing of unused frequency bands due to its non-parametric sensing ability and computationally low complexity. However, spectrum sensing becomes more challenging in Cognitive Vehicular Networks (CVNs) due to Secondary User’s (SU’s) mobility and often yields a detection performance loss as compared to static scenarios. In order to mitigate the impact of reduced detection performance due to mobility, the usage of an improved version of energy detection technique is proposed in this paper. Usage of Improved Energy Detection (IED) technique in CVNs results more than 10% increment in DSA/CR system performance. In this paper, we study the joint impact of SU’s sensing range, PU’s protection range and SU’s mobility model on the PU Activity using IED technique in CVNs, with detection probability and probability of false alarm as the performance metrics. Also, we derive a closed form expression for the probability of PU being inside SU’s sensing range. Based on the proposed framework, numerical results show great agreement with analysis, yielding a superior performance.
{"title":"On the Joint Impact of SU Mobility and PU Activity in Cognitive Vehicular Networks with Improved Energy Detection","authors":"Om Thakkar, Dhaval K. Patel, Y. Guan, Sumei Sun, Yoong Choon Chang, J. Lim","doi":"10.1109/VTCSpring.2019.8746441","DOIUrl":"https://doi.org/10.1109/VTCSpring.2019.8746441","url":null,"abstract":"Dynamic Spectrum Access (DSA)/Cognitive Radio (CR) systems access the channel in an opportunistic, noninterfering manner with the primary network, thus being a promising approach to solve the problem of spectrum scarcity. Energy Detection, a spectrum sensing technique for DSA/CR systems, is widely used for blind sensing of unused frequency bands due to its non-parametric sensing ability and computationally low complexity. However, spectrum sensing becomes more challenging in Cognitive Vehicular Networks (CVNs) due to Secondary User’s (SU’s) mobility and often yields a detection performance loss as compared to static scenarios. In order to mitigate the impact of reduced detection performance due to mobility, the usage of an improved version of energy detection technique is proposed in this paper. Usage of Improved Energy Detection (IED) technique in CVNs results more than 10% increment in DSA/CR system performance. In this paper, we study the joint impact of SU’s sensing range, PU’s protection range and SU’s mobility model on the PU Activity using IED technique in CVNs, with detection probability and probability of false alarm as the performance metrics. Also, we derive a closed form expression for the probability of PU being inside SU’s sensing range. Based on the proposed framework, numerical results show great agreement with analysis, yielding a superior performance.","PeriodicalId":134773,"journal":{"name":"2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124459151","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 : 2019-04-01DOI: 10.1109/VTCSpring.2019.8746593
Yuki Kanaya, M. Bandai
Earth observation satellites obtain various data from the Earth and its surrounding environment. The amount of data handled by Earth observation satellites has increased in step with the improved performance of observation equipment. By using free-space optics (FSO) for satellite communication, much faster data transmission becomes possible. However, FSO is influenced by atmospheric conditions, which can disrupt the optical link between a satellite and ground station (GS). In contrast, a radio-frequency (RF) link is hardly ever influenced by atmospheric conditions, and communication can continue even when clouds pass between the satellite and GS. In this paper, we propose RF/FSO hybrid routing for satellite constellations. In the proposed method, when the FSO link between a satellite and GS is disrupted due to atmospheric phenomena, a detour path through other satellites with a functioning FSO link to the GS is established to increase the total amount of data transmitted to the GS. Using numerical calculations, we show that the proposed method is effective for increasing the total amount of data transmitted from a satellite to its GS compared to the conventional method.
{"title":"An RF/FSO Hybrid Routing for Satellite Constellation Systems","authors":"Yuki Kanaya, M. Bandai","doi":"10.1109/VTCSpring.2019.8746593","DOIUrl":"https://doi.org/10.1109/VTCSpring.2019.8746593","url":null,"abstract":"Earth observation satellites obtain various data from the Earth and its surrounding environment. The amount of data handled by Earth observation satellites has increased in step with the improved performance of observation equipment. By using free-space optics (FSO) for satellite communication, much faster data transmission becomes possible. However, FSO is influenced by atmospheric conditions, which can disrupt the optical link between a satellite and ground station (GS). In contrast, a radio-frequency (RF) link is hardly ever influenced by atmospheric conditions, and communication can continue even when clouds pass between the satellite and GS. In this paper, we propose RF/FSO hybrid routing for satellite constellations. In the proposed method, when the FSO link between a satellite and GS is disrupted due to atmospheric phenomena, a detour path through other satellites with a functioning FSO link to the GS is established to increase the total amount of data transmitted to the GS. Using numerical calculations, we show that the proposed method is effective for increasing the total amount of data transmitted from a satellite to its GS compared to the conventional method.","PeriodicalId":134773,"journal":{"name":"2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125212954","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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