Electronics and Communications in Japan (Part I: Communications)最新文献_第8页

Comparison of MUSIC algorithms using gradient- and integral-type mode vectors for direction of arrival and angular spread estimation 梯度型和积分型模式矢量MUSIC算法在到达方向和角扩展估计中的比较

Electronics and Communications in Japan (Part I: Communications) Pub Date : 2007-02-21 DOI: 10.1002/ecja.20208

Hiroyuki Hotta, Nobuyoshi Kikuma, Kunio Sakakibara, Hiroshi Hirayama

{"title":"Comparison of MUSIC algorithms using gradient- and integral-type mode vectors for direction of arrival and angular spread estimation","authors":"Hiroyuki Hotta, Nobuyoshi Kikuma, Kunio Sakakibara, Hiroshi Hirayama","doi":"10.1002/ecja.20208","DOIUrl":"10.1002/ecja.20208","url":null,"abstract":"A generalized mode vector that simultaneously uses the differential coefficient component of the mode vector has been proposed for estimating the direction of arrival of incident waves having angular spread. In this paper, the authors first examined this generalized mode vector and proposed a gradient-type MUSIC algorithm that uses the differential coefficient component of the mode vector independently for estimating the direction of arrival. Then they used a computer simulation in which the waves having angular spread were considered to be a group of scattered waves to compare this algorithm with regard to the performance for estimating the direction of arrival with an integral-type MUSIC algorithm that uses simple integration, which they proposed separately. To improve the estimation precision degradation that occurs when the signal correlation is low among scattered waves that exist within the angular spread when using the integral-type MUSIC algorithm, the authors proposed a combined-type MUSIC algorithm that incorporated the gradient-type MUSIC algorithm in the integral-type MUSIC algorithm and used this to examine the performance for estimating the direction of arrival and angular spread again. The results of the comparison of the gradient-type MUSIC algorithm and integral-type MUSIC algorithm confirmed that the two algorithms have conflicting properties related to the signal correlation among scattered waves that exist within the angular spread. Also, the investigation related to the combined-type MUSIC algorithm indicated that estimation precision degradation that occurs when the signal correlation is low among scattered waves when using the integral-type MUSIC algorithm was reduced as expected. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(6): 53– 64, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20208","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 6","pages":"53-64"},"PeriodicalIF":0.0,"publicationDate":"2007-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20208","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79368915","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}

引用次数: 7

Channel modeling of nondirected wireless infrared indoor diffuse link 无向无线红外室内漫射链路信道建模

Electronics and Communications in Japan (Part I: Communications) Pub Date : 2007-02-21 DOI: 10.1002/ecja.20352

Naoki Hayasaka, Takeshi Ito

引用次数: 43

Measurement method of one-way differential delay for end-to-end path selection on multihoming 多归属端到端路径选择的单向差分时延测量方法

Electronics and Communications in Japan (Part I: Communications) Pub Date : 2007-02-21 DOI: 10.1002/ecja.20321

Kiyoshi Ogawa, Arata Sawai, Noboru Iida, Masaki Bandai, Takashi Watanabe

{"title":"Measurement method of one-way differential delay for end-to-end path selection on multihoming","authors":"Kiyoshi Ogawa, Arata Sawai, Noboru Iida, Masaki Bandai, Takashi Watanabe","doi":"10.1002/ecja.20321","DOIUrl":"10.1002/ecja.20321","url":null,"abstract":"In a multihoming communications environment in which multiple communications interfaces are connected to a single terminal to use multiple paths, if different paths are used for the going-out path and return path, more efficient information communications may be possible. To enable this to occur, one-way delay must be taken into account to select the appropriate interface. However, it is generally difficult to directly obtain an accurate one-way delay because the communications path load varies according to such factors as the time period and amount of communications, and the going-out path delay and return path delay cannot be easily separated. In this paper, the authors simply obtain the one-way approximate differential delays from multiple patterns of round-trip delay combinations and propose a method of selecting the path based on these differentials. This method has such features as control packets for measurement and synchronization with the communication destination which are unnecessary and it is extendable since it does not depend on the network layer. The authors also implemented the proposed method on a computer by using ICMP and evaluated it experimentally in various types of multihoming communications environments. The results showed that one-way path selection is possible and that the proposed method is effective. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(6): 29–42, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20321","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 6","pages":"29-42"},"PeriodicalIF":0.0,"publicationDate":"2007-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20321","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73602780","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}

引用次数: 2

Low-delay scheduling algorithm that considers fairness between ports 考虑端口间公平性的低延迟调度算法

Electronics and Communications in Japan (Part I: Communications) Pub Date : 2007-02-21 DOI: 10.1002/ecja.20313

Hirotada Kawakami, Koichi Asatani

{"title":"Low-delay scheduling algorithm that considers fairness between ports","authors":"Hirotada Kawakami, Koichi Asatani","doi":"10.1002/ecja.20313","DOIUrl":"10.1002/ecja.20313","url":null,"abstract":"A Virtual Output Queuing (VOQ) input buffer type switch provided with a buffer in each input port is proposed in this paper as an input buffer type switch that avoids Head-of-Line (HoL) blocking. A scheduling algorithm for a multiple VOQ input buffer type switch is also proposed. As a representative algorithm we use a Two-Dimensional Round Robin (2DRR) scheduling algorithm that achieves low-delay and has iSLIP to avoid starvation as well as high fairness between ports. This paper also proposes a layered scheduling algorithm for a VOQ input buffer type switch with an objective of fairness between ports and switching with lower delay. The frequency of packets not being output is reduced regardless of whether an output port is empty by using up patterns of all I/O pairs in N input N output switches. The N input N output switching is divided into smaller units. Fairness between the units is achieved by successively shifting the order of priority of each unit that will be switched. Simulations were used to evaluate the effectiveness of the proposed scheduling algorithm. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(6): 43–52, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20313","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 6","pages":"43-52"},"PeriodicalIF":0.0,"publicationDate":"2007-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20313","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84507241","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}

引用次数: 0

Characteristics of biological tissue equivalent phantoms applied to UWB communications 应用于超宽带通信的生物组织等效幻象特性

Electronics and Communications in Japan (Part I: Communications) Pub Date : 2007-01-08 DOI: 10.1002/ecja.20300

Takuya Takimoto, Teruo Onishi, Kazuyuki Saito, Masaharu Takahashi, Shinji Uebayashi, Koichi Ito

{"title":"Characteristics of biological tissue equivalent phantoms applied to UWB communications","authors":"Takuya Takimoto, Teruo Onishi, Kazuyuki Saito, Masaharu Takahashi, Shinji Uebayashi, Koichi Ito","doi":"10.1002/ecja.20300","DOIUrl":"10.1002/ecja.20300","url":null,"abstract":"Previously, the authors studied biological tissue equivalent phantoms able to simulate the electrical constants of the human body in the 3- to 6-GHz band in a single composition ratio. Therefore, in this paper, we examined how to study the antenna characteristics using the phantom when extended to a bandwidth including 900 MHz to 3 GHz and 6 to 10 GHz and performed a quantitative study focusing on the electrical constants of the phantom. The result clearly showed hardly any effect of divergence of the phantom's electrical constants from the target values on the antenna input impedance, radiation efficiency, and radiation directivity. Therefore, in the entire ultra-wideband (UWB), this phantom can be accurately evaluated through antenna characteristic measurements and is clearly effective. Furthermore, differences due to the divergence of the phantom's electrical constants from the target values in the entire UWB bandwidth (3 to 10 GHz) are within ±3% for the average local specific absorption rate (SAR) inside the phantom caused by the electromagnetic wave energy radiated from the antenna. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(5): 48–55, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20300","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 5","pages":"48-55"},"PeriodicalIF":0.0,"publicationDate":"2007-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20300","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90585331","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}

引用次数: 30

A proposal for an efficient message-flooding scheme using a link-cut technique 提出了一种使用链路切断技术的高效消息泛洪方案

Electronics and Communications in Japan (Part I: Communications) Pub Date : 2007-01-08 DOI: 10.1002/ecja.20351

Kenji Ohtsuka, Taku Ishihara, Shigeo Shioda

引用次数: 2

A method of direction finding for dispersive electromagnetic pulses 色散电磁脉冲测向方法

Electronics and Communications in Japan (Part I: Communications) Pub Date : 2007-01-08 DOI: 10.1002/ecja.20327

Minoru Tsutsui, Shigeo Konagaya, Tadayoshi Kagawa

{"title":"A method of direction finding for dispersive electromagnetic pulses","authors":"Minoru Tsutsui, Shigeo Konagaya, Tadayoshi Kagawa","doi":"10.1002/ecja.20327","DOIUrl":"10.1002/ecja.20327","url":null,"abstract":"A new measurement method which can determine the direction of arrival of a pulse electromagnetic wave with frequency dispersion characteristics has been developed. The direction of arrival is determined by conventional data analysis for an electric field component and two magnetic field components. The sensor system is composed of a vertical dipole antenna and two search coils oriented in perpendicular directions in the horizontal plane. The major part of the analysis of the detected signal is composed of the derivation of the spectrum with frequency dispersion from the pulse waveform and the calculation of the direction of arrival from the amplitude and the phase obtained for each frequency in the dispersion characteristics. By the proposed method, the direction of arrival can be determined even when a frequency-dependent delay is produced in propagation (frequency dispersion). The method is applied to lightning discharge pulses, and it is shown that the direction of arrival can be determined with high accuracy. Thus, the method can be used for continuous observation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(5): 23–32, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20327","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 5","pages":"23-32"},"PeriodicalIF":0.0,"publicationDate":"2007-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20327","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87062534","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}

引用次数: 14

A comparison of steady-state characteristics of buck-type DC-DC converter using DSP 基于DSP的buck型DC-DC变换器稳态特性比较

Electronics and Communications in Japan (Part I: Communications) Pub Date : 2007-01-08 DOI: 10.1002/ecja.20357

Fujio Kurokawa, Wataru Okamoto, Hirofumi Matsuo

{"title":"A comparison of steady-state characteristics of buck-type DC-DC converter using DSP","authors":"Fujio Kurokawa, Wataru Okamoto, Hirofumi Matsuo","doi":"10.1002/ecja.20357","DOIUrl":"10.1002/ecja.20357","url":null,"abstract":"In this paper, we describe the relationship between the control constants and the output voltage regulation characteristics of a buck DC/DC converter for a digital control system using P-I-D control, the minimum phase FIR filter, and the moving average constructed from digital signal processors. Furthermore, the digital control method and its control constants were studied comparatively from the perspective of suppressing the oscillations based on the limit cycle. We found that when an 8-bit analog-to-digital (A-D) converter having a quantization width of about 80 mV was used, we could obtain excellent results similar to the minimum phase FIR filter and the moving average, achieve an excellent output voltage regulation of less than 1.3% for fluctuations from a light load to the rated 2 A for the target 10 V, and suppress oscillations to less than 20 mV. In the P-I-D control method, adequate output voltage regulation characteristics were obtained, but oscillations could not be suppressed. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(5): 1–10, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20357","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 5","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2007-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20357","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90156154","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}

引用次数: 16

Birefringence generation mechanism in a fiber Fabry-Perot etalon buried in a fiber connector housing 埋在光纤连接器外壳中的光纤法布里-珀罗标准子的双折射产生机制

Electronics and Communications in Japan (Part I: Communications) Pub Date : 2007-01-08 DOI: 10.1002/ecja.20174

Mitsuhiro Tateda, Shizuka Otake, Toshihiro Shintaku, Takashige Omatsu

{"title":"Birefringence generation mechanism in a fiber Fabry-Perot etalon buried in a fiber connector housing","authors":"Mitsuhiro Tateda, Shizuka Otake, Toshihiro Shintaku, Takashige Omatsu","doi":"10.1002/ecja.20174","DOIUrl":"10.1002/ecja.20174","url":null,"abstract":"We derived an analytical model according to which birefringence in a fiber Fabry-Perot etalon occurs due to the anisotropy of adhesive layers in the cementing of the fiber to the ferrule. We found that the birefringence was proportional to the product of the difference in the coefficients of linear expansion of the fiber and ferrule materials, the change in temperature, the Young's modulus of the adhesive, and the anisotropy of the adhesive layer thickness. In addition, by measuring the birefringence of six fiber Fabry-Perot etalons fabricated using three types of adhesives that differed in curing shrinkage and viscosity, we showed that the birefringence has a positive correlation with the curing shrinkage of the adhesive used. The measured temperature dependence of birefringence was consistent with the order of magnitude of the value calculated using the derived model, confirming the validity of the proposed model. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(5): 56–62, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20174","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 5","pages":"56-62"},"PeriodicalIF":0.0,"publicationDate":"2007-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20174","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82319837","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}

引用次数: 2

A study on robust beam-forming algorithm for search operation in distributed array radar 分布式阵列雷达搜索操作的鲁棒波束形成算法研究

Electronics and Communications in Japan (Part I: Communications) Pub Date : 2007-01-08 DOI: 10.1002/ecja.20325

Shoji Matsuda, Hiroyuki Hashiguchi, Shoichiro Fukao

{"title":"A study on robust beam-forming algorithm for search operation in distributed array radar","authors":"Shoji Matsuda, Hiroyuki Hashiguchi, Shoichiro Fukao","doi":"10.1002/ecja.20325","DOIUrl":"10.1002/ecja.20325","url":null,"abstract":"A distributed array radar is a radar configuration to form a high-gain receive beam suited to an equivalent large-aperture antenna by arbitrarily distributing and positioning multiple small antennas and coherently synthesizing their received signals. When the placement intervals of the small antennas are sufficiently longer than the wavelength, the conventional beamformer generates many grating lobes and, therefore, ambiguity in the estimated direction of the target. This paper shows that robust Capon beamformer using the norm constraints is effective as a beamforming method that suppresses these grating lobes when using distributed array radar in search radar and prevents a decrease of the search efficiency caused by the reduction in beam width. In addition, an improvement based on diagonal loading is proposed for this algorithm in order to improve the search efficiency. Finally, we consider the parameter optimization and demonstrate the performance using numerical simulation examples. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(5): 33–47, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20325","PeriodicalId":100405,"journal":{"name":"Electronics and Communications in Japan (Part I: Communications)","volume":"90 5","pages":"33-47"},"PeriodicalIF":0.0,"publicationDate":"2007-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecja.20325","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84775163","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}

引用次数: 0