{"title":"Special Cluster in Emerging Communication Technologies in Conjunction with Main Topics of ICETC 2023","authors":"","doi":"10.23919/comex.2024TCF0001","DOIUrl":"https://doi.org/10.23919/comex.2024TCF0001","url":null,"abstract":"This special cluster is primarily intended as a collection of extended research papers originally presented at the International Conference on Emerging Technologies for Communications (ICETC) 2023. The ICETC was inaugurated in 2020 and has since become the flagship conference of the IEICE Communications Society (IEICE-CS). The conference encompasses all research areas of the IEICE-CS and is designed to facilitate the generation of synergies between researchers from different technical fields. The fourth ICETC was held in Sapporo, Japan, in 2023, with a 100% face-to-face format and over 200 participants.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10634098","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Simple Wavelet Transform with Fine Time and Frequency Sampling","authors":"Tomoya Yamaoka;Tadashi Oshima","doi":"10.23919/comex.2024XBL0117","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0117","url":null,"abstract":"Wavelet transform performs frequency transform with different time window widths to enable accurate time-frequency analysis for sensing. Time and frequency sampling of scalogram are not uniform to eliminate redundancy. One method achieves fine time sampling with fewer operations, but the frequency direction sampling is not uniform or fine, and sidelobes are high. To address these problems, this study proposes a simple wavelet transform with fine time and frequency sampling. The proposed method consists of phase multiplication and signal addition. Frequency transform of any time window width is possible by changing the additive width of the signal. Furthermore, by adding the results, wavelet transform using a triangular window that lowers sidelobes is realized using a small number of complex multiplication operations. When the proposed method is applied to a chirp waveform, the frequency transition of the signal could be finely confirmed.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633230","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nonlinearity Tolerance of Time-Domain Single Carrier Index Modulation Signals in Optical Access Links","authors":"Daichi Aoki;Wataru Imajuku","doi":"10.23919/comex.2024XBL0121","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0121","url":null,"abstract":"This paper investigates the impact of nonlinear optical effects on Time-Domain Single Carrier Index Modulation (TDSC-IM) optical signals in Wavelength Division Multiplexing-Passive Optical Network (WDM-PON) systems that use standard single-mode fibers. Simulations indicate that TDSC-IM optical signals with high peak-to-average power ratio (PAPR) can maintain sufficient signal-to-noise ratios (SNRs) in C-band transmission in optical delivery networks with standard single mode fibers, while O-band transmission suffers larger nonlinear effects. This paper demonstrates that the degradation in the SNRs of the 25 GBaud quaternary phase shift keying (QPSK) based TDSC-IM optical signals can be less than 1 dB for 8 wavelength channel WDM-PON systems with 50 GHz spacing.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633222","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142376627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Power Saving Control Method with Adaptive FEC Decoder in Optical Access Network","authors":"Kaito Kubo;Amila Kariyawasam;Shunji Kimura","doi":"10.23919/comex.2024XBL0124","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0124","url":null,"abstract":"With the increasing demand for network services, the power consumption of equipment has been steadily rising each year, especially in the access network domain. Passive Optical Networks (PON) traditionally operate on the principle of ensuring service provision to the farthest user. Consequently, performance tends to be excessive for short to medium distances, leading to surplus power consumption. In this study, we address the issue of reducing power consumption in access networks by tackling surplus power. Our approach involves utilizing three different types of Reed-Solomon (RS) decoders to apply appropriate forward error correction (FEC) redundancy based on transmission distance, aiming to lower power consumption of RS decoders in optical network units (ONUs). Subsequently, we evaluated the power saving of FEC decoding in a 10G-class PON and report over 48% average power saving compared to the conventional homogeneous FEC-based network.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633221","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reflection-Phase Calculation of Circularly Polarized Folded Reflectarray Antennas with Low Profile, High Efficiency, and Arbitrary Aperture Distribution","authors":"Makoto Sano;Ryuji Kuse;Takeshi Fukusako","doi":"10.23919/comex.2024XBL0115","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0115","url":null,"abstract":"This paper presents a new concept of designing circularly polarized folded reflectarray (CPFRA) antennas. By applying the dual-reflector shaping technique to the CPFRA antennas, the reflection-phase distributions of the two reflecting surfaces comprising the CPFRA antennas are modified to realize low profile, high aperture efficiency, and arbitrary aperture-field distribution simultaneously. Numerical simulations based on the geometrical optics show that the aperture efficiency can be improved up to around 100% by realizing uniform aperture-field distribution and reducing the spillover. Designs of CPFRA antennas with low sidelobe levels are also presented.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633229","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Hamka Ibrahim;Subuh Pramono;Jing-Yuan Wang;Yu-Fan Cai;Feri Adriyanto;Josaphat Tetuko Sri Sumantyo
{"title":"Speckle Correction Filter Based on Spatial Polarimetric Coherence for Full Polarimetric Synthetic Aperture Radar Image","authors":"Muhammad Hamka Ibrahim;Subuh Pramono;Jing-Yuan Wang;Yu-Fan Cai;Feri Adriyanto;Josaphat Tetuko Sri Sumantyo","doi":"10.23919/comex.2024XBL0125","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0125","url":null,"abstract":"Polarimetric synthetic aperture radar (PolSAR) image exhibits a high degree of spatial information. However, the PolSAR image is subjected to speckle noise, which degrades the information quality. A speckle correction filter is proposed in this paper based on spatial polarimetric coherence. Evidence of polarimetric coherence between spatial neighboring pixels is presented. It shows that polarimetric coherence is highly correlated with neighboring pixels. Based on these characteristics, a speckle correction filter is proposed by calculating the polarimetric coherency level on a selected neighboring pixel. A correction is applied to the pixel which has a low polarimetric coherence level. A generalized three-step adaptive filter is proposed, including neighbor selection, coherency criterion, and incoherent correction. The influence of the filter on scattering mechanisms is compared by using eigenvalue-based decomposition. Qualitatively, the result shows the proposed correction filter removes the outliers in the low entropy region. Quantitively the filter can suppress the speckle noise and its variance up to 19.08%.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633226","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142376979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Path Loss Model from 922 MHz to 28 GHz in Office Environment","authors":"Kensuke Sakamoto;Ayaka Sakaguchi;Yuki Yamakawa;Waka Mimura;Hirokazu Sawada;Azril Haniz;Fumihide Kojima;Takeshi Matsumura","doi":"10.23919/comex.2024XBL0120","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0120","url":null,"abstract":"To build a stable wireless communication system in an indoor environment, it is necessary to perform highly accurate simulations of radio wave propagation characteristics. The ITU-R Recommendation P series, especially ITU-R P.1238, lists estimation models for propagation loss in indoor environments under various conditions. However, there are a few cases in which propagation loss has been measured at various frequencies in the same building and under the same conditions. In these cases, necessary parameters may not be described, meaning that simulation cannot be easily performed. In this paper, we measure the radio wave propagation characteristics on the same floor and across floors for the 922 MHz to 28 GHz frequency band, which is often used in office spaces. We then apply a path loss model to each frequency and calculate the coefficient of office environment (\u0000<tex>$N$</tex>\u0000) and inter-floor attenuation \u0000<tex>$(L_{f}(n))$</tex>\u0000.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633227","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Difference-Beam Operation in a Center-Fed Dual-Polarized Parallel-Plate Waveguide Slot Array Antenna","authors":"Huanqian Xiong;Jiro Hirokawa;Takashi Tomura","doi":"10.23919/comex.2024XBL0100","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0100","url":null,"abstract":"This letter deals with the difference-beam operation in a centerfeed dual-polarized parallel-plate waveguide slot array antenna at 24.5GHz, which consists of two orthogonally arranged 20×19 arrays of radiating slot pairs. A center-feeding scheme is employed in this design. Each rectangular feeding waveguide, fed by a probe, can feed half of the radiating panel, enabling easy control of the phase difference. Experimental results show that the monopulse antenna array has a bandwidth of 12.8% for reflections below −10 dB while it produces the sum beams, and 13.3% to produce the difference beams. Port isolation between the sum mode and difference mode is above 15 dB within the working frequency band. The measured realized gain of the sum beam is 31.3 dBi at 24.5 GHz, and the measured null-depth is below −33.9 dB for both polarizations.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10591717","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Distributed UAV Management System Inspired by Packet-Switched Networks","authors":"Takahiko Haraguchi;Hiroshi Katada;Taku Yamazaki;Takumi Miyoshi;Ryo Yamamoto;Kiyoshi Ueda","doi":"10.23919/comex.2024XBL0101","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0101","url":null,"abstract":"Unmanned aerial vehicles (UAVs) are expected to be used in various applications such as delivery services and sensing from airspaces in smart cities. In the future, UAV control systems must address a densely mixed environment comprising various services and users regardless of individuals or businesses. However, users cannot flexibly join or leave the system because of their centralized design. This letter proposes a distributed UAV management system inspired by packet-switched networks, to address dense UAV environments. The proposed system controls autonomous UAVs as packets in packet-switched networks. Each UAV flies along a path composed of links between ground beacon devices as routers. We analyzed the characteristics of the proposed system in dense situations using computer simulation. Simulation results indicate that the proposed system can handle numerous UAVs based on packet-switched networks.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10591721","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142090889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation of Shadowing Effect on Channel Observation for Spectrum Sharing Access","authors":"Hideya So;Hayato Soya","doi":"10.23919/comex.2024XBL0106","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0106","url":null,"abstract":"Spectrum sharing, in which multiple wireless systems share the same radio resources, has been considered to improve frequency utilization efficiency. As a spectrum sharing without control signals, a technique that observes the usage of radio resources, called channel occupation ratio, used by other systems and selects a vacant channel has been considered. However, previous studies have simplified the model of the interfering system, which is different from the real environment. In wireless communications, fluctuations in received power occur due to shadowing caused by the location and the surrounding environment. Previous studies have not clarified the effect of received power fluctuation due to shadowing on observing the occupancy rate. This letter formulates the effects on the observation results of received power fluctuations due to the location of interfering stations and shadowing. Computer simulations with randomly placed interfering stations and shadowing environments show that the proposed formulation almost matches the observed results.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10591720","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142090747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}