Pub Date : 2021-04-21DOI: 10.1109/WTS51064.2021.9433684
S. M. Aghajanzadeh, Ming Jian
With the ultra-dense structure of future mmWave networks, the need for a fast and cost-effective pattern nulling technique is evident. In this paper, we investigate three different phase-only nulling methods to provide spatial filtering capability for the phased array antennas. First, the idea of small-phase perturbation is generalized to planar arrays which are more appropriate for mmWave applications. Two sub-optimal methods are further proposed which successively synthesize the nulls to reduce the computational latency. The proposed approaches provide a fast pattern re-configurability for 5G applications.
{"title":"Phase-Only Pattern Nulling of Planar Antenna Arrays in mmWave Communications","authors":"S. M. Aghajanzadeh, Ming Jian","doi":"10.1109/WTS51064.2021.9433684","DOIUrl":"https://doi.org/10.1109/WTS51064.2021.9433684","url":null,"abstract":"With the ultra-dense structure of future mmWave networks, the need for a fast and cost-effective pattern nulling technique is evident. In this paper, we investigate three different phase-only nulling methods to provide spatial filtering capability for the phased array antennas. First, the idea of small-phase perturbation is generalized to planar arrays which are more appropriate for mmWave applications. Two sub-optimal methods are further proposed which successively synthesize the nulls to reduce the computational latency. The proposed approaches provide a fast pattern re-configurability for 5G applications.","PeriodicalId":443112,"journal":{"name":"2021 Wireless Telecommunications Symposium (WTS)","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116030784","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 : 2021-04-21DOI: 10.1109/WTS51064.2021.9433708
Qian Dong, F. Zhu, Yanning Cai, Liangda Fang, Mi Lu
Mobility of nodes in Wireless Sensor Networks (WSNs) brings formidable challenges to protocol design. A mobility estimation algorithm is the prerequisite for evaluating link quality, localizing nodes and excogitating a signal threshold to trigger possible handoff. The radio Received Signal Strength Indicator (RSSI) integrated in sensors has been widely used due to its low economy cost and moderate energy consumption. The distance of separation between adjacent nodes can be estimated by reading RSSI when a good portion of electromagnetic wave propagates in a line-of-sight link. However, the measurement results of RSSI fluctuate heavily because of fading signal and disturbing background noise. This paper investigates the reliability of RSSI for exterior sensor positioning. To display the one-to-one mapping between RSSI and distance, a series of static experiments are conducted and a reference curve is established. To mitigate the fluctuation of raw RSSI samples, a set of mobile experiments are carried out and five filtering methods are employed. The mitigation effects are evaluated by the Root Mean Square Error (RMSE) values. Though the overall optimal RMSE achieves 0.84, which is significantly lower than that of the raw samples, it is still possible that one RSSI corresponds to two or more distances, and the maximum difference between them can reach 2.97 meters. Because this error is intolerable for many applications, it is not authentic to gauge the distance between mobile nodes only based on RSSI in exterior environment.
{"title":"Analysis of RSSI Feasibility for Sensor Positioning in Exterior Environment","authors":"Qian Dong, F. Zhu, Yanning Cai, Liangda Fang, Mi Lu","doi":"10.1109/WTS51064.2021.9433708","DOIUrl":"https://doi.org/10.1109/WTS51064.2021.9433708","url":null,"abstract":"Mobility of nodes in Wireless Sensor Networks (WSNs) brings formidable challenges to protocol design. A mobility estimation algorithm is the prerequisite for evaluating link quality, localizing nodes and excogitating a signal threshold to trigger possible handoff. The radio Received Signal Strength Indicator (RSSI) integrated in sensors has been widely used due to its low economy cost and moderate energy consumption. The distance of separation between adjacent nodes can be estimated by reading RSSI when a good portion of electromagnetic wave propagates in a line-of-sight link. However, the measurement results of RSSI fluctuate heavily because of fading signal and disturbing background noise. This paper investigates the reliability of RSSI for exterior sensor positioning. To display the one-to-one mapping between RSSI and distance, a series of static experiments are conducted and a reference curve is established. To mitigate the fluctuation of raw RSSI samples, a set of mobile experiments are carried out and five filtering methods are employed. The mitigation effects are evaluated by the Root Mean Square Error (RMSE) values. Though the overall optimal RMSE achieves 0.84, which is significantly lower than that of the raw samples, it is still possible that one RSSI corresponds to two or more distances, and the maximum difference between them can reach 2.97 meters. Because this error is intolerable for many applications, it is not authentic to gauge the distance between mobile nodes only based on RSSI in exterior environment.","PeriodicalId":443112,"journal":{"name":"2021 Wireless Telecommunications Symposium (WTS)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128437430","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 : 2021-04-21DOI: 10.1109/WTS51064.2021.9433678
J. G. D. Junior, F. A. Brito-Filho
Field Programmable Gate Arrays (FPGAs) have been widely used in applications involving hard signal processing with reconfiguration capabilities. One promising application that requires those capabilities is Software Defined Radio (SDR). In this work a novel design of SDR modem based on FPGA is proposed. Using an experimental setup with an embedded sigma-delta A/D converter and a multimode (ASK, FSK and PSK) modem as proof of concept and with most of the tasks running in FPGA. The modem was tested and proved to be efficient using just about 1 % of available logic blocks of the adopted FPGA with a maximum operating frequency as high as 148 MHz for low cost devices, being possible the implementation in several models of FPGAs available in the market.
{"title":"A Multimode FPGA-based Modem with Embedded Σ-Δ Analog-to-Digital Converter for Software Defined Radio","authors":"J. G. D. Junior, F. A. Brito-Filho","doi":"10.1109/WTS51064.2021.9433678","DOIUrl":"https://doi.org/10.1109/WTS51064.2021.9433678","url":null,"abstract":"Field Programmable Gate Arrays (FPGAs) have been widely used in applications involving hard signal processing with reconfiguration capabilities. One promising application that requires those capabilities is Software Defined Radio (SDR). In this work a novel design of SDR modem based on FPGA is proposed. Using an experimental setup with an embedded sigma-delta A/D converter and a multimode (ASK, FSK and PSK) modem as proof of concept and with most of the tasks running in FPGA. The modem was tested and proved to be efficient using just about 1 % of available logic blocks of the adopted FPGA with a maximum operating frequency as high as 148 MHz for low cost devices, being possible the implementation in several models of FPGAs available in the market.","PeriodicalId":443112,"journal":{"name":"2021 Wireless Telecommunications Symposium (WTS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125865778","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 : 2021-04-21DOI: 10.1109/WTS51064.2021.9433676
V. Savaux, C. Delacourt, Patrick Savelli
This paper deals with a general and complete analysis of the frame error rate in LoRa system, not only considering the payload error rate, but also the sync word (carrying network information) and the header (carrying control information) error rates. It is proved that, in the high signal-to-noise ratio (SNR) range, it is more likely to reject a LoRa frame due to an erroneous sync word estimation rather than an erroneous header or payload decoding, due to the fact that it is not coded. The theoretical results are then verified through simulations.
{"title":"Considering Sync Word and Header Error Rates for Performance Assessment in LoRa System","authors":"V. Savaux, C. Delacourt, Patrick Savelli","doi":"10.1109/WTS51064.2021.9433676","DOIUrl":"https://doi.org/10.1109/WTS51064.2021.9433676","url":null,"abstract":"This paper deals with a general and complete analysis of the frame error rate in LoRa system, not only considering the payload error rate, but also the sync word (carrying network information) and the header (carrying control information) error rates. It is proved that, in the high signal-to-noise ratio (SNR) range, it is more likely to reject a LoRa frame due to an erroneous sync word estimation rather than an erroneous header or payload decoding, due to the fact that it is not coded. The theoretical results are then verified through simulations.","PeriodicalId":443112,"journal":{"name":"2021 Wireless Telecommunications Symposium (WTS)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124981588","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 : 2021-04-21DOI: 10.1109/WTS51064.2021.9433681
Naor Zohar
This study suggests using a user-initiated data gathering from power-limited and even passive wireless sensor networks (WSNs), that either power limitation or poor cellular coverage prevents them from communicating directly with wireless networks. While previous studies focused on WSNs that continuously transmit their data, the focus of this study is on passive WSNs. The key idea is that instead of receiving the data transmitted by the WSN, an external device (a reader), such as an unnamed aerial vehicle (UAV), or a smartphone is used to read the data stored in the sensor nodes, and then to deliver it to the cloud, in which it is stored and processed. The focus of this study is on the rate at which the passive sensor nodes should be polled. That is, to find the minimal monitoring rate that still guarantees accurate and reliable data collection.The proposed scheme enables us to deploy wireless sensor networks over a large geographic area (e.g., for agricultural applications), in which the cellular coverage is very poor if any. Furthermore, the usage of initiated data collection can enable the deployment of passive WSNs. Thus, can significantly reduce both the operational cost, as well as the deployment cost, of the WSN.
{"title":"Efficient Data Gathering from Passive Wireless Sensor Networks","authors":"Naor Zohar","doi":"10.1109/WTS51064.2021.9433681","DOIUrl":"https://doi.org/10.1109/WTS51064.2021.9433681","url":null,"abstract":"This study suggests using a user-initiated data gathering from power-limited and even passive wireless sensor networks (WSNs), that either power limitation or poor cellular coverage prevents them from communicating directly with wireless networks. While previous studies focused on WSNs that continuously transmit their data, the focus of this study is on passive WSNs. The key idea is that instead of receiving the data transmitted by the WSN, an external device (a reader), such as an unnamed aerial vehicle (UAV), or a smartphone is used to read the data stored in the sensor nodes, and then to deliver it to the cloud, in which it is stored and processed. The focus of this study is on the rate at which the passive sensor nodes should be polled. That is, to find the minimal monitoring rate that still guarantees accurate and reliable data collection.The proposed scheme enables us to deploy wireless sensor networks over a large geographic area (e.g., for agricultural applications), in which the cellular coverage is very poor if any. Furthermore, the usage of initiated data collection can enable the deployment of passive WSNs. Thus, can significantly reduce both the operational cost, as well as the deployment cost, of the WSN.","PeriodicalId":443112,"journal":{"name":"2021 Wireless Telecommunications Symposium (WTS)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131480932","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 : 2021-04-21DOI: 10.1109/WTS51064.2021.9433713
Mitchell Fantuz, Michel Kulhandjian, C. D’amours
In this paper, we examine the bit error rate (BER) performance of low-density spreading (LDS) systems employing the minimum mean square error (MMSE) and parallel interference cancellation (MMSE-PIC) detector in frequency-selective fading channels while additionally proposing a precoding scheme for multipath channels which effectively transforms the multipath channel into a single path channel. Numerical studies illustrate that the precoding scheme is effective and that reliable communication is possible, even in harsh multipath conditions.
{"title":"Low Complexity PIC-MMSE Detector for LDS Systems over Frequency-Selective Channels","authors":"Mitchell Fantuz, Michel Kulhandjian, C. D’amours","doi":"10.1109/WTS51064.2021.9433713","DOIUrl":"https://doi.org/10.1109/WTS51064.2021.9433713","url":null,"abstract":"In this paper, we examine the bit error rate (BER) performance of low-density spreading (LDS) systems employing the minimum mean square error (MMSE) and parallel interference cancellation (MMSE-PIC) detector in frequency-selective fading channels while additionally proposing a precoding scheme for multipath channels which effectively transforms the multipath channel into a single path channel. Numerical studies illustrate that the precoding scheme is effective and that reliable communication is possible, even in harsh multipath conditions.","PeriodicalId":443112,"journal":{"name":"2021 Wireless Telecommunications Symposium (WTS)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132161891","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 : 2021-03-23DOI: 10.1109/WTS51064.2021.9433686
B. Sahoo, S. Swain, Hung-Yu Wei, M. Sarkar
The unlicensed spectrum is recently considered as one of the defining solutions to meet the steadily growing traffic demand. This, in turn, has led to the enhancement for LTE in Release-13 to enable Licensed-Assisted Access (LAA) operations. The design of the medium access control (MAC) protocol for the LAA system to harmonically coexist with the incumbent WLAN system operating in an unlicensed band is critical and challenging. In this paper, we consider an Integrated Access and Backhaul (IAB) system coexisting with a Wi-Fi network operating at millimeter-wave (mmWave) unlicensed spectrum, for which a listen-before-talk-based (LBT) based medium access mechanism is carefully designed. Additionally, we have considered an in-band system that supports both access and backhaul in a single node where the small-cell or the IAB nodes compete with the Wi-Fi for medium access. We present comprehensive experimental results and give design insights based on the simulation results.
{"title":"Medium Access Strategies for Integrated Access and Backhaul at mmWaves Unlicensed Spectrum","authors":"B. Sahoo, S. Swain, Hung-Yu Wei, M. Sarkar","doi":"10.1109/WTS51064.2021.9433686","DOIUrl":"https://doi.org/10.1109/WTS51064.2021.9433686","url":null,"abstract":"The unlicensed spectrum is recently considered as one of the defining solutions to meet the steadily growing traffic demand. This, in turn, has led to the enhancement for LTE in Release-13 to enable Licensed-Assisted Access (LAA) operations. The design of the medium access control (MAC) protocol for the LAA system to harmonically coexist with the incumbent WLAN system operating in an unlicensed band is critical and challenging. In this paper, we consider an Integrated Access and Backhaul (IAB) system coexisting with a Wi-Fi network operating at millimeter-wave (mmWave) unlicensed spectrum, for which a listen-before-talk-based (LBT) based medium access mechanism is carefully designed. Additionally, we have considered an in-band system that supports both access and backhaul in a single node where the small-cell or the IAB nodes compete with the Wi-Fi for medium access. We present comprehensive experimental results and give design insights based on the simulation results.","PeriodicalId":443112,"journal":{"name":"2021 Wireless Telecommunications Symposium (WTS)","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124032764","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 : 2021-03-21DOI: 10.1109/WTS51064.2021.9433677
Ming-Chin Chuang
Due to the rapid development of wireless network technology, a variety of application services have been proposed. Recently, the Internet-of-vehicles (IoV) has received lots of attention from industry, government, academics and research units. Unfortunately, the wireless spectrum resources are very limited. There are some problems in vehicle ad hoc networks (VANETs), such as channel interference, competition and waste of wireless spectrum. Although cognitive radio technology has been proposed to improve spectrum utilization, there are still many issues that need to be addressed. For example, when a vehicle hands over the base stations (BSs), the issue of the spectrum handover needs to be considered. The network performance gets worse as the vehicle moves faster. Therefore, this paper proposes a cooperation-assisted spectrum handover (CASH) scheme. In CASH, each vehicle uses cognitive radio technology to collect the surrounding spectrum information, exchanges information by vehicle-to-vehicle collaboration technology and then executes a pre-scan mechanism to improve performance. We hope that the proposed method can reduce the delay time of the spectrum handover and improve the spectrum utilization. Finally, the simulation results show that our proposed method outperforms other existing schemes. In spectrum utilization, CASH is about 25% better than that of the traditional method. In average scan time, the time of CASH is about 5 times less than the time of the traditional full scan method.
{"title":"Cooperation-Assisted Spectrum Handover Mechanism in Vehicular Ad Hoc Networks","authors":"Ming-Chin Chuang","doi":"10.1109/WTS51064.2021.9433677","DOIUrl":"https://doi.org/10.1109/WTS51064.2021.9433677","url":null,"abstract":"Due to the rapid development of wireless network technology, a variety of application services have been proposed. Recently, the Internet-of-vehicles (IoV) has received lots of attention from industry, government, academics and research units. Unfortunately, the wireless spectrum resources are very limited. There are some problems in vehicle ad hoc networks (VANETs), such as channel interference, competition and waste of wireless spectrum. Although cognitive radio technology has been proposed to improve spectrum utilization, there are still many issues that need to be addressed. For example, when a vehicle hands over the base stations (BSs), the issue of the spectrum handover needs to be considered. The network performance gets worse as the vehicle moves faster. Therefore, this paper proposes a cooperation-assisted spectrum handover (CASH) scheme. In CASH, each vehicle uses cognitive radio technology to collect the surrounding spectrum information, exchanges information by vehicle-to-vehicle collaboration technology and then executes a pre-scan mechanism to improve performance. We hope that the proposed method can reduce the delay time of the spectrum handover and improve the spectrum utilization. Finally, the simulation results show that our proposed method outperforms other existing schemes. In spectrum utilization, CASH is about 25% better than that of the traditional method. In average scan time, the time of CASH is about 5 times less than the time of the traditional full scan method.","PeriodicalId":443112,"journal":{"name":"2021 Wireless Telecommunications Symposium (WTS)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129326601","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 : 2020-10-10DOI: 10.1109/WTS51064.2021.9433680
V. Savaux, G. Ferré
This paper deals with the bit error rate (BER) of LoRa signal over Rayleigh and Rice channels. Exact analytical expressions of the BER in LoRa systems have been proposed in the literature, but they are not tractable and raise problems of computation precision. This is mainly due to the fact that these expressions involve sums of binomial coefficients, leading to extremely large numbers and leading to problem of precision. We then hereby suggest asymptotic expressions of the BER, which are at the same time tractable and accurate over a wide BER range. These expressions do not involve sums of binomial coefficients anymore, but only closed-form functions, and can then be easily obtained through computer simulations.
{"title":"Simple Asymptotic BER Expressions for LoRa System over Rice and Rayleigh Channels","authors":"V. Savaux, G. Ferré","doi":"10.1109/WTS51064.2021.9433680","DOIUrl":"https://doi.org/10.1109/WTS51064.2021.9433680","url":null,"abstract":"This paper deals with the bit error rate (BER) of LoRa signal over Rayleigh and Rice channels. Exact analytical expressions of the BER in LoRa systems have been proposed in the literature, but they are not tractable and raise problems of computation precision. This is mainly due to the fact that these expressions involve sums of binomial coefficients, leading to extremely large numbers and leading to problem of precision. We then hereby suggest asymptotic expressions of the BER, which are at the same time tractable and accurate over a wide BER range. These expressions do not involve sums of binomial coefficients anymore, but only closed-form functions, and can then be easily obtained through computer simulations.","PeriodicalId":443112,"journal":{"name":"2021 Wireless Telecommunications Symposium (WTS)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116329657","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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