{"title":"Special Cluster in Antennas and Propagation Technologies 2024","authors":"","doi":"10.23919/comex.2025SPF0001","DOIUrl":"https://doi.org/10.23919/comex.2025SPF0001","url":null,"abstract":"The objective of this special cluster is to present advanced technologies in antennas and propagation, including next-generation mobile communication systems, MIMO, PAN/BAN, metamaterials, and wireless power transmission. The scope also covers electromagnetic wave theory and related areas, with a focus on emerging topics such as metamaterials, nano-electromagnetics, and their antenna applications.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"14 6","pages":"205-205"},"PeriodicalIF":0.3,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11021590","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196829","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":"Transmission Timing Synchronization Method Based on Results of Cross-Correlation in Distributed TDMA-MIMO Radar","authors":"Yoshiki Takahashi;Hiroyoshi Yamada;Tadashi Oshima","doi":"10.23919/comex.2025SPL0015","DOIUrl":"https://doi.org/10.23919/comex.2025SPL0015","url":null,"abstract":"High angular resolution is required for millimeter-wave radar, which is currently being studied for application. One method for improving angular resolution is distributed Time Division Multiple Access (TDMA)-Multiple Input Multiple Output (MIMO) radar. In order to realize a distributed TDMA-MIMO radar using millimeter wave radar, it is necessary to use delay circuit with extremely high precision. Such highprecision timing control is difficult to achieve with millimeter waves, which makes distributed radar difficult to implement. In this letter, we propose a timing synchronization method based on the results of cross-correlation calculations, assuming that delay circuit with sufficient precision cannot be used due to cost and other reasons, and demonstrate its effectiveness through computer simulations and evaluations using experimental data.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"14 6","pages":"233-237"},"PeriodicalIF":0.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10964020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196833","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":"Phase Retrieval Method Using a Single Planar Near-Field Measurement","authors":"Inhyeok Choi;Hiroyuki Arai","doi":"10.23919/comex.2025XBL0020","DOIUrl":"https://doi.org/10.23919/comex.2025XBL0020","url":null,"abstract":"In recent years, wireless measurement methods in the near-field are developed for antenna performance evaluation. The phase measurement is difficult in near-field above the millimeter wave band, then a method to retrieve the phase using only amplitude information from a sampling plane is investigated. In this paper, we propose a method that utilizes only a single planar measurement as a faster and simpler phase retrieval method.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"14 6","pages":"254-256"},"PeriodicalIF":0.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10964021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196914","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":"Ultra-High Splitting Ratio Access Network with Optical Power Feeding Using a Hollow Core Fiber","authors":"Shumpei Kimura;Zhixin Liu;Motoharu Matsuura;Takeshi Takagi;Kazunori Mukasa;Satoru Okamoto;Naoaki Yamanaka;Hiroyuki Tsuda","doi":"10.23919/comex.2025XBL0050","DOIUrl":"https://doi.org/10.23919/comex.2025XBL0050","url":null,"abstract":"We propose and investigate an ultra-high splitting ratio passive optical network (PON) using a hollow core fiber (HCF). An HCF is used for one of the downstream link for power delivery through feeding light, which powers an optical amplifier for the upstream that improves uplink power budget. We perform simulations to evaluate the maximum splitting ratio of the proposed HCF-based PONs. We show that the proposed system can support up to 4096 users in 25 Gbps non-return-to-zero (NRZ) intensity-modulation (IM) and direct detection (DD), as well as 1024 users in 25 Gbaud 16QAM transmission.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"14 6","pages":"263-266"},"PeriodicalIF":0.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10964026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196832","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}
Junichi Naganawa;Yoshio Kosuge;Jun Kitaori;Hirohisa Tajima;Tadashi Koga
{"title":"Demonstration of Aircraft Localization by TDOA, AOA, and Barometric Altitude at Two Sites","authors":"Junichi Naganawa;Yoshio Kosuge;Jun Kitaori;Hirohisa Tajima;Tadashi Koga","doi":"10.23919/comex.2025XBL0045","DOIUrl":"https://doi.org/10.23919/comex.2025XBL0045","url":null,"abstract":"Aircraft localization systems that use time difference of arrival (TDOA) measurements, called wide-area multilateration (WAM) systems, have been deployed for air traffic control. Although WAM performs better than radar, it requires a large number of ground stations. A possible solution by which to reduce the number of stations is to obtain additional measurements, such as the angle of arrival (AOA) and barometric altitude. However, the feasibility of hybrid localization has not been experimentally proven. Therefore, this study presents an experiment on aircraft localization using TDOA, AOA, and barometric altitude measurements to demonstrate that aircraft localization at only two sites is possible.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"14 6","pages":"246-249"},"PeriodicalIF":0.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10964017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196877","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":"Far-Field $kQ$ Theory for Hertzian Dipoles in Two- and Three-Dimensional Infinite Free Spaces","authors":"Takashi Ohira","doi":"10.23919/comex.2025SPL0013","DOIUrl":"https://doi.org/10.23919/comex.2025SPL0013","url":null,"abstract":"This study considers the electromagnetic coupling between two Hertzian dipoles located in two- and three-dimensional free spaces. First, we briefly review the generalized <tex>$kQ$</tex> theory with respect to the reciprocal two-port impedance matrix. The <tex>$kQ$</tex> concept is then applied to a basic 2D problem, where a pair of Hertzian dipoles is sandwiched between infinitely wide parallel conductor plates. One dipole is excited by a sinusoidal current, and the other dipole observes the voltage induced across it. Solving a 2D Helmholtz equation yields <tex>$kQ=sqrt{lambda/d}/pi$</tex>, where <tex>$lambda$</tex> is the wavelength and <tex>$d$</tex> is the distance between the dipoles. Similarly, we apply the <tex>$kQ$</tex> theory to a 3D problem and obtain <tex>$kQ=3lambda/4pi d$</tex>. Because a Hertzian dipole is a building block for practical antennas, the results of this study will offer a theoretical foundation for developing various types of wireless power transfer systems.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"14 6","pages":"238-241"},"PeriodicalIF":0.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10964018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196831","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":"Implementation of Density Evolution for Polar Codes Based on Monte Carlo Simulation","authors":"Nobuhiko Miki;Satoshi Suyama;Satoshi Nagata","doi":"10.23919/comex.2025XBL0044","DOIUrl":"https://doi.org/10.23919/comex.2025XBL0044","url":null,"abstract":"Density evolution (DE) plays a fundamental role in the analysis of channel coding systems employing iterative decoding, and it is a valuable tool to design such systems. This letter discusses the implementation of DE for polar codes. In this letter, fast Fourier transform based methods are difficult to apply due to the difficulty in optimizing the parameters, and therefore, DE is performed using a Monte Carlo simulation. Finally, examples of the applications of this method are presented.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"14 6","pages":"250-253"},"PeriodicalIF":0.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10964027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196566","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":"Inter-Symbol Interference Mitigation Using Adaptive Dataset Selection in the Parzen Window Method","authors":"Shoma Ito;Hirokazu Kubota;Yuji Miyoshi","doi":"10.23919/comex.2025XBL0047","DOIUrl":"https://doi.org/10.23919/comex.2025XBL0047","url":null,"abstract":"We propose a detection method based on the Parzen window method to mitigate inter-symbol interference. This method selects a trained dataset based on the neighboring symbols, following a decision feedback approach. Simulation results show the proposed method achieved a 3.3 dB improvement in the Q value for a QPSK signal degraded by inter-symbol interference.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"14 6","pages":"260-262"},"PeriodicalIF":0.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10964025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196915","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":"Compensating Image Overlay 16QAM Using Dual Cameras for Rolling Shutter-Based Screen Camera Communication","authors":"Hayate Ohtani;Wataru Chujo;Kentaro Kobayashi","doi":"10.23919/comex.2025XBL0033","DOIUrl":"https://doi.org/10.23919/comex.2025XBL0033","url":null,"abstract":"Image overlay uplink screen camera communication consisting of a small display with LED backlight modulation and an indoor rolling shutter camera has been studied. A previous study demonstrated that image overlay QPSK was achieved by compensating pixel values of the overlaid image using dual cameras. However, even after the compensation, variation in the pixel values remained, making it difficult to realize further M-ary modulation. In this study, a compensation method taking both the overlaid image and backlight modulation into account is proposed. Constellation, error vector magnitude, and bit error rate for image overlay 16QAM are experimentally evaluated using dual cameras.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"14 6","pages":"242-245"},"PeriodicalIF":0.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10964019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196625","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":"Satellite Signal Arrival Direction Estimation to Reduce Multipath Errors Using General-Purpose Receivers and the Multiple Signal Classification (MUSIC) Method in Satellite Positioning","authors":"Hiromune Namie;Dai Nagafuchi;Takemitsu Fujita","doi":"10.23919/comex.2025XBL0034","DOIUrl":"https://doi.org/10.23919/comex.2025XBL0034","url":null,"abstract":"Satellite positioning has become accurate to the millimeter order with the use of carrier phase observation data for distance measurement, but one type of error namely multipath error remaines. In this research, as a preliminary step to reducing multipath errors using the data observed with an array antenna, we used a general-purpose receiver and the MUltiple SIgnal Classification (MUSIC) method to determine the direction of arrival of satellite signals. It was found that the direction of arrival of satellite signals can be estimated from pseudo carrier phase observation data using the MUSIC method.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"14 6","pages":"257-259"},"PeriodicalIF":0.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10964029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196878","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}