Pub Date : 2019-09-01DOI: 10.1109/VTCFall.2019.8891558
Kenta Tsuge, Yuyuan Chang, K. Fukawa, S. Suyama, Y. Okumura
Massive multiple-input multiple-output (MIMO) will be employed in the 5th generation mobile communications (5G). To implement the massive MIMO, hybrid beamforming (HB) is one of the most promising techniques, because HB is composed of the analog beamforming (AB) and the digital beamforming (DB) and thus can decrease the number of baseband and radio frequency (RF) circuits significantly. Furthermore, HB can reduce a much larger amount of cost and power consumption than the full DB (FDB) configuration, which requires one baseband and RF circuit for each antenna element. This paper proposes a scheme to estimate both phases for phase rotators in AB and a precoding matrix for DB so that HB can approximate the block diagonalization (BD), which can nullify interference from the undesired users and form efficient transmit beams. For time division duplex (TDD) multiuser MIMO communications, the proposed scheme estimates the FDB channel matrix in the uplink (UL) and the phase for the phase rotators of AB in the downlink (DL). After obtaining an equivalent channel matrix from both the estimated FDB channel matrix and the AB precoding matrix, the scheme estimates the DB precoding matrix in DL from the equivalent channel matrix so that HB can approximate BD in DL. Computer simulations demonstrate that HB employing the proposed scheme can achieve DL average bit error rate (BER) performances that are little inferior to those of FDB.
{"title":"Parameter Estimation for Block Diagonalization Based Hybrid Beamforming in Massive MIMO Communications","authors":"Kenta Tsuge, Yuyuan Chang, K. Fukawa, S. Suyama, Y. Okumura","doi":"10.1109/VTCFall.2019.8891558","DOIUrl":"https://doi.org/10.1109/VTCFall.2019.8891558","url":null,"abstract":"Massive multiple-input multiple-output (MIMO) will be employed in the 5th generation mobile communications (5G). To implement the massive MIMO, hybrid beamforming (HB) is one of the most promising techniques, because HB is composed of the analog beamforming (AB) and the digital beamforming (DB) and thus can decrease the number of baseband and radio frequency (RF) circuits significantly. Furthermore, HB can reduce a much larger amount of cost and power consumption than the full DB (FDB) configuration, which requires one baseband and RF circuit for each antenna element. This paper proposes a scheme to estimate both phases for phase rotators in AB and a precoding matrix for DB so that HB can approximate the block diagonalization (BD), which can nullify interference from the undesired users and form efficient transmit beams. For time division duplex (TDD) multiuser MIMO communications, the proposed scheme estimates the FDB channel matrix in the uplink (UL) and the phase for the phase rotators of AB in the downlink (DL). After obtaining an equivalent channel matrix from both the estimated FDB channel matrix and the AB precoding matrix, the scheme estimates the DB precoding matrix in DL from the equivalent channel matrix so that HB can approximate BD in DL. Computer simulations demonstrate that HB employing the proposed scheme can achieve DL average bit error rate (BER) performances that are little inferior to those of FDB.","PeriodicalId":6713,"journal":{"name":"2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78238309","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}
Traditional low earth orbit mobile satellite systems (LEO-MSSs) cannot satisfy the demands of huge capacity in ultra-dense regions. In addition, due to the frequent passive group handover caused by high speed movement of LEO satellites, quality of service (QoS) can hardly be satisfied. In this paper, we propose an extensible multi-layer architecture model based on traditional LEO-MSSs to solve these problems. In the proposed architecture, we introduce high-altitude platforms (HAPs) and terrestrial relays (TRs) to cover ultra-dense regions and provide communication services. We also present the theoretical analysis of the system capacity and handover rate to evaluate the benefits brought by the proposed architecture. Moreover, we compare the system performance after adding HAPs and TRs in different scenarios. Simulation results validate that HAPs and TRs can increase capacity and reduce handover rate, and show how the capacity and handover rate are improved.
{"title":"An Extensible Multi-Layer Architecture Model Based on LEO-MSS and Performance Analysis","authors":"Yitao Li, Haichao Wei, Letian Li, Yuxi Han, Jiaxi Zhou, Wuyang Zhou","doi":"10.1109/VTCFall.2019.8891397","DOIUrl":"https://doi.org/10.1109/VTCFall.2019.8891397","url":null,"abstract":"Traditional low earth orbit mobile satellite systems (LEO-MSSs) cannot satisfy the demands of huge capacity in ultra-dense regions. In addition, due to the frequent passive group handover caused by high speed movement of LEO satellites, quality of service (QoS) can hardly be satisfied. In this paper, we propose an extensible multi-layer architecture model based on traditional LEO-MSSs to solve these problems. In the proposed architecture, we introduce high-altitude platforms (HAPs) and terrestrial relays (TRs) to cover ultra-dense regions and provide communication services. We also present the theoretical analysis of the system capacity and handover rate to evaluate the benefits brought by the proposed architecture. Moreover, we compare the system performance after adding HAPs and TRs in different scenarios. Simulation results validate that HAPs and TRs can increase capacity and reduce handover rate, and show how the capacity and handover rate are improved.","PeriodicalId":6713,"journal":{"name":"2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78382419","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 : 2019-09-01DOI: 10.1109/VTCFall.2019.8890975
Weibin Ma, Lin Zhang, Furong Fang, Jing Bian
Light fidelity (LiFi) provides a promising solution for indoor high-speed wireless transmissions. However, the dense deployment of access points (APs) and the unity frequency reuse in LiFi system may induce the inter-cell interference (ICI) issue. In this paper, we consider the combined transmission (CT) which converts harmful interference to useful signals and thereby combats the ICI, and propose a dynamic user-centric clustering scheme for the downlink LiFi system. In our design, with the objective of maximizing the system throughput under proportional fairness constraints, the CT clustering is formulated as a mixed-integer non- linear programming (MINLP) problem. Then we set up an exact potential game (EPG) model, where the Nash equilibrium is found via the best response algorithm, to provide a suboptimal solution to the MINLP problem. Simulation results demonstrate that the LiFi system using our presented scheme exhibits a higher throughput and a better satisfaction degree than that employing the single-point transmission (SPT) scheme.
{"title":"Dynamic User-Centric Clustering Design for Combined Transmission in Downlink LiFi System","authors":"Weibin Ma, Lin Zhang, Furong Fang, Jing Bian","doi":"10.1109/VTCFall.2019.8890975","DOIUrl":"https://doi.org/10.1109/VTCFall.2019.8890975","url":null,"abstract":"Light fidelity (LiFi) provides a promising solution for indoor high-speed wireless transmissions. However, the dense deployment of access points (APs) and the unity frequency reuse in LiFi system may induce the inter-cell interference (ICI) issue. In this paper, we consider the combined transmission (CT) which converts harmful interference to useful signals and thereby combats the ICI, and propose a dynamic user-centric clustering scheme for the downlink LiFi system. In our design, with the objective of maximizing the system throughput under proportional fairness constraints, the CT clustering is formulated as a mixed-integer non- linear programming (MINLP) problem. Then we set up an exact potential game (EPG) model, where the Nash equilibrium is found via the best response algorithm, to provide a suboptimal solution to the MINLP problem. Simulation results demonstrate that the LiFi system using our presented scheme exhibits a higher throughput and a better satisfaction degree than that employing the single-point transmission (SPT) scheme.","PeriodicalId":6713,"journal":{"name":"2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76117596","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 : 2019-09-01DOI: 10.1109/VTCFall.2019.8891376
Xin Gao, Xi Huang, Ziyu Shao
In fog-assisted IoT systems, to achieve best quality of service with ultra-low latency, resource-limited IoT user nodes may offload some tasks to nearby fog nodes, a.k.a. task offloading, to accelerate their processing. However, it remains non-trivial and challenging to decide when and which fog node to offload to. If offloaded, user tasks may experience unexpectedly long latency in face of system uncertainties, such as wireless channel dynamics, variety in task processing time, and resource contention on fog nodes. Moreover, feedback signals such as processing latency can be delayed and even go outdated due to non- stationarity, thereby degrading the effectiveness of system statistic learning and decision making. In this paper, we study task offloading problem for fog-assisted IoT systems in a non-stationary environment with delayed feedback. By leveraging a drift detector and queue methods, we propose TOS-BB and TOS-BS, two online task offloading schemes with bandit learning that endeavor to achieve ultra-low task latency. Simulation results show that both schemes outperform the benchmark while achieving close- to-optimal performance with short task latency.
{"title":"Online Task Offloading with Bandit Learning in Fog-Assisted IoT Systems","authors":"Xin Gao, Xi Huang, Ziyu Shao","doi":"10.1109/VTCFall.2019.8891376","DOIUrl":"https://doi.org/10.1109/VTCFall.2019.8891376","url":null,"abstract":"In fog-assisted IoT systems, to achieve best quality of service with ultra-low latency, resource-limited IoT user nodes may offload some tasks to nearby fog nodes, a.k.a. task offloading, to accelerate their processing. However, it remains non-trivial and challenging to decide when and which fog node to offload to. If offloaded, user tasks may experience unexpectedly long latency in face of system uncertainties, such as wireless channel dynamics, variety in task processing time, and resource contention on fog nodes. Moreover, feedback signals such as processing latency can be delayed and even go outdated due to non- stationarity, thereby degrading the effectiveness of system statistic learning and decision making. In this paper, we study task offloading problem for fog-assisted IoT systems in a non-stationary environment with delayed feedback. By leveraging a drift detector and queue methods, we propose TOS-BB and TOS-BS, two online task offloading schemes with bandit learning that endeavor to achieve ultra-low task latency. Simulation results show that both schemes outperform the benchmark while achieving close- to-optimal performance with short task latency.","PeriodicalId":6713,"journal":{"name":"2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72692243","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 : 2019-09-01DOI: 10.1109/VTCFall.2019.8891596
David Reyes, M. Beach, M. Rumney, J. Haine, E. Mellios
The goals for 5G New Radio (NR) technology are to deliver wireless communications with higher capacity, performance, and efficiency compared with current mobile technologies. 5G NR will make effective use of the millimetre wave frequency spectrum to achieve these goals. However, these higher frequencies experience greater signal attenuation due to increased path loss and blockages. To overcome these, it is necessary to use high-gain directional active array antenna systems (AAS) at both ends of the communications link, which can steer the radiating beam in multiple directions. The cost-effective and compact implementation of the AAS requires the RF transceiver and antenna array to be highly integrated, making it impossible to independently test the performance of the constituent components due to the lack of inter-stage connectors. Further, the propagation channel is highly dynamic in both temporal and spatial domains. Hence, conformance testing of such systems is most effectively carried out using Over-The-Air (OTA) testing, since traditional conducted non-spatial test methods will not predict the radiated performance in space and the action of the RF transceiver, in particular, the beamformer. This paper presents a highly novel millimetre wave OTA test method facilitating the excitation of a Device Under Test (DUT) from multiple dynamic narrow angles of illumination, thus representing typical operating conditions and avoids the need for physical RF connections. This new method exploits the reflective properties of ellipsoidal surfaces and offers a cost-effective means when compared with other OTA test methods.
{"title":"Novel Over-the-Air Test Method for 5G Millimetre Wave Devices, Based on Elliptical Cylinder Reflectors","authors":"David Reyes, M. Beach, M. Rumney, J. Haine, E. Mellios","doi":"10.1109/VTCFall.2019.8891596","DOIUrl":"https://doi.org/10.1109/VTCFall.2019.8891596","url":null,"abstract":"The goals for 5G New Radio (NR) technology are to deliver wireless communications with higher capacity, performance, and efficiency compared with current mobile technologies. 5G NR will make effective use of the millimetre wave frequency spectrum to achieve these goals. However, these higher frequencies experience greater signal attenuation due to increased path loss and blockages. To overcome these, it is necessary to use high-gain directional active array antenna systems (AAS) at both ends of the communications link, which can steer the radiating beam in multiple directions. The cost-effective and compact implementation of the AAS requires the RF transceiver and antenna array to be highly integrated, making it impossible to independently test the performance of the constituent components due to the lack of inter-stage connectors. Further, the propagation channel is highly dynamic in both temporal and spatial domains. Hence, conformance testing of such systems is most effectively carried out using Over-The-Air (OTA) testing, since traditional conducted non-spatial test methods will not predict the radiated performance in space and the action of the RF transceiver, in particular, the beamformer. This paper presents a highly novel millimetre wave OTA test method facilitating the excitation of a Device Under Test (DUT) from multiple dynamic narrow angles of illumination, thus representing typical operating conditions and avoids the need for physical RF connections. This new method exploits the reflective properties of ellipsoidal surfaces and offers a cost-effective means when compared with other OTA test methods.","PeriodicalId":6713,"journal":{"name":"2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77757995","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 : 2019-09-01DOI: 10.1109/VTCFall.2019.8891353
M. Lerch, P. Svoboda, Valentin Platzgummer, M. Rupp
In recent years, many public high-speed trains have been upgraded with active in-train repeaters in order to improve mobile service coverage for train passengers. With a repeater in place, the user equipment perceives a wireless channel with a direct path and an indirect path through the repeater delayed by several micro seconds. In vehicular scenarios, the pick-up antenna experiences a wide range of signal levels. Due to the limited output power of the repeater, the paths may arrive with similar power, which can be a problem for OFDM based systems like LTE. Drive tests in LTE have shown that uplink performance degrades, even if the delay stays within the cyclic prefix. In order to gain a better understanding, we conducted a laboratory experiment to measure, quantify, and analyze the impact of two-path channels, with different delays and power levels, onto a live LTE network. Results show uplink performance degradation and increased transmit power even for delays smaller than the cyclic prefix due to non-optimal time-synchronization. In the system under test this degradation already starts at a path power difference of 15 dB and reaches up to 50% at equal path power levels.
{"title":"Analysis of LTE in Two-Path Vehicular Repeater Channels","authors":"M. Lerch, P. Svoboda, Valentin Platzgummer, M. Rupp","doi":"10.1109/VTCFall.2019.8891353","DOIUrl":"https://doi.org/10.1109/VTCFall.2019.8891353","url":null,"abstract":"In recent years, many public high-speed trains have been upgraded with active in-train repeaters in order to improve mobile service coverage for train passengers. With a repeater in place, the user equipment perceives a wireless channel with a direct path and an indirect path through the repeater delayed by several micro seconds. In vehicular scenarios, the pick-up antenna experiences a wide range of signal levels. Due to the limited output power of the repeater, the paths may arrive with similar power, which can be a problem for OFDM based systems like LTE. Drive tests in LTE have shown that uplink performance degrades, even if the delay stays within the cyclic prefix. In order to gain a better understanding, we conducted a laboratory experiment to measure, quantify, and analyze the impact of two-path channels, with different delays and power levels, onto a live LTE network. Results show uplink performance degradation and increased transmit power even for delays smaller than the cyclic prefix due to non-optimal time-synchronization. In the system under test this degradation already starts at a path power difference of 15 dB and reaches up to 50% at equal path power levels.","PeriodicalId":6713,"journal":{"name":"2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78108473","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 : 2019-09-01DOI: 10.1109/VTCFall.2019.8891527
Mohammad Irfan Khan, S. Sesia, Jérôme Härri
Transmit Rate Control (TRC) for V2X networks is critical for distributed channel resource allocation, limiting the channel usage per vehicle while preventing channel saturation. Similarly, efficiently distributing the limited transmit opportunities among multiple services of a vehicle is necessary, but has not been sufficiently studied. In this paper, we present a multi-V2X service resource orchestrator composed of two complementary mechanisms: (i) a multi-factor prioritization function, (ii) a budgetary scheduler allowing smooth resource earning/spending. Simulation-based evaluations showed improved access time for various V2X services under restricted resources and enhanced control on resource balancing between V2X services.
{"title":"In Vehicle Resource Orchestration for Multi-V2X Services","authors":"Mohammad Irfan Khan, S. Sesia, Jérôme Härri","doi":"10.1109/VTCFall.2019.8891527","DOIUrl":"https://doi.org/10.1109/VTCFall.2019.8891527","url":null,"abstract":"Transmit Rate Control (TRC) for V2X networks is critical for distributed channel resource allocation, limiting the channel usage per vehicle while preventing channel saturation. Similarly, efficiently distributing the limited transmit opportunities among multiple services of a vehicle is necessary, but has not been sufficiently studied. In this paper, we present a multi-V2X service resource orchestrator composed of two complementary mechanisms: (i) a multi-factor prioritization function, (ii) a budgetary scheduler allowing smooth resource earning/spending. Simulation-based evaluations showed improved access time for various V2X services under restricted resources and enhanced control on resource balancing between V2X services.","PeriodicalId":6713,"journal":{"name":"2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79309517","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 : 2019-09-01DOI: 10.1109/VTCFall.2019.8891192
Sirui Yang, Tabatowski-Bush Ben, Weidong Xiang
This paper presents a real-time long short-term memory (LSTM) recurrent neural network (RNN) to trace and predict the GPS positioning errors within next one to several seconds, offering an enhance GPS positioning. The proposed LSTM prediction model was further verified over extensive experimental data captured in cities and metropolitans, urbans and highways across several middle and eastern States of the United States. The prediction accuracy of the proposed real-time LSTM can be within less than 1-3% of its ground true values outperforms those results gained by conventional statistics and linear prediction models.
{"title":"Build Up a Real-Time LSTM Positioning Error Prediction Model for GPS Sensors","authors":"Sirui Yang, Tabatowski-Bush Ben, Weidong Xiang","doi":"10.1109/VTCFall.2019.8891192","DOIUrl":"https://doi.org/10.1109/VTCFall.2019.8891192","url":null,"abstract":"This paper presents a real-time long short-term memory (LSTM) recurrent neural network (RNN) to trace and predict the GPS positioning errors within next one to several seconds, offering an enhance GPS positioning. The proposed LSTM prediction model was further verified over extensive experimental data captured in cities and metropolitans, urbans and highways across several middle and eastern States of the United States. The prediction accuracy of the proposed real-time LSTM can be within less than 1-3% of its ground true values outperforms those results gained by conventional statistics and linear prediction models.","PeriodicalId":6713,"journal":{"name":"2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79427007","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 : 2019-09-01DOI: 10.1109/VTCFall.2019.8891306
Jakob Thrane, D. Zibar, H. Christiansen
Accurate channel models for predicting received power under slow fading impairments are essential for planning 5G solutions due to the increased range of possible transmission frequencies. The densification of base stations will pose an increased number of complex coverage and capacity situations where flexible and computational simple channel models are essential. In this paper, we study state-of-the-art empirical channel models, more specifically ITU-R M.2412 and 3GPP 38.901, and their performance on experimental measurements at 2630 MHz for LTE-A reference parameters such as RSRP. A crude ray-tracing model is implemented for reference. The results show an increase in the predictive performance of approximately 4 dB at 811 MHz compared to higher frequencies of 2630 MHz.
{"title":"Comparison of Empirical and Ray-Tracing Models for Mobile Communication Systems at 2.6 GHz","authors":"Jakob Thrane, D. Zibar, H. Christiansen","doi":"10.1109/VTCFall.2019.8891306","DOIUrl":"https://doi.org/10.1109/VTCFall.2019.8891306","url":null,"abstract":"Accurate channel models for predicting received power under slow fading impairments are essential for planning 5G solutions due to the increased range of possible transmission frequencies. The densification of base stations will pose an increased number of complex coverage and capacity situations where flexible and computational simple channel models are essential. In this paper, we study state-of-the-art empirical channel models, more specifically ITU-R M.2412 and 3GPP 38.901, and their performance on experimental measurements at 2630 MHz for LTE-A reference parameters such as RSRP. A crude ray-tracing model is implemented for reference. The results show an increase in the predictive performance of approximately 4 dB at 811 MHz compared to higher frequencies of 2630 MHz.","PeriodicalId":6713,"journal":{"name":"2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81273203","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 : 2019-09-01DOI: 10.1109/VTCFall.2019.8891583
E. Marshakov, Gleb Balitskiy, K. Andreev, A. Frolov
Massive machine-type communications (mMTC) is one of the key application scenarios for future 5G networks. In the literature, this problem is known as unsourced random access. We propose a polar code based scheme for the unsourced random access Gaussian channel. This scheme is based on T-fold irregular repetition slotted ALOHA (IRSA). We use polar codes as slot codes and investigate their practical performance in T-user MAC. We compare two possible decoding techniques: joint successive cancellation algorithm and joint iterative algorithm. In order to optimize the codes (choose frozen bits), we propose a specialized and efficient design algorithm. Finally, we investigate the performance of the resulting scheme by means of simulations and conclude that replacing of LDPC codes with polar codes in IRSA scheme leads to a significant performance gain.
{"title":"A Polar Code Based Unsourced Random Access for the Gaussian MAC","authors":"E. Marshakov, Gleb Balitskiy, K. Andreev, A. Frolov","doi":"10.1109/VTCFall.2019.8891583","DOIUrl":"https://doi.org/10.1109/VTCFall.2019.8891583","url":null,"abstract":"Massive machine-type communications (mMTC) is one of the key application scenarios for future 5G networks. In the literature, this problem is known as unsourced random access. We propose a polar code based scheme for the unsourced random access Gaussian channel. This scheme is based on T-fold irregular repetition slotted ALOHA (IRSA). We use polar codes as slot codes and investigate their practical performance in T-user MAC. We compare two possible decoding techniques: joint successive cancellation algorithm and joint iterative algorithm. In order to optimize the codes (choose frozen bits), we propose a specialized and efficient design algorithm. Finally, we investigate the performance of the resulting scheme by means of simulations and conclude that replacing of LDPC codes with polar codes in IRSA scheme leads to a significant performance gain.","PeriodicalId":6713,"journal":{"name":"2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81542195","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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