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Proceedings of GLOBECOM '95最新文献

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Impact of the phase noise generated from semiconductor optical amplifiers on the size of optical space switches 半导体光放大器相位噪声对光空间开关尺寸的影响
Proceedings of GLOBECOM '95 Pub Date : 1995-11-14 DOI: 10.1109/GLOCOM.1995.502776
J. Pires
{"title":"Impact of the phase noise generated from semiconductor optical amplifiers on the size of optical space switches","authors":"J. Pires","doi":"10.1109/GLOCOM.1995.502776","DOIUrl":"https://doi.org/10.1109/GLOCOM.1995.502776","url":null,"abstract":"Optical space switch matrices can be designed by interconnecting properly multiple 2/spl times/2 switches based on semiconductor optical amplifiers (SOAs). The size of these switching structures is limited by many phenomena, including phase noise generated by SOAs, which can be a serious drawback if coherent modulation schemes are used in the network. This paper examines this problem, for a DPSK direct detection system. It is found that there is an optimum level for the switch input power, and the phase noise limits the number of 2/spl times/2 switches, which can be cascaded, to about 200, for a bit rate in the gigabit/s range.","PeriodicalId":152724,"journal":{"name":"Proceedings of GLOBECOM '95","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131795508","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
Effects of carrier phase and chip timing errors on the capacity of a quadriphase spread BPSK modulated DS-CDMA system 载波相位和芯片时序误差对四相扩展BPSK调制DS-CDMA系统容量的影响
Proceedings of GLOBECOM '95 Pub Date : 1995-11-14 DOI: 10.1109/GLOCOM.1995.502576
M. O. Sunay, Peter J. McLane
{"title":"Effects of carrier phase and chip timing errors on the capacity of a quadriphase spread BPSK modulated DS-CDMA system","authors":"M. O. Sunay, Peter J. McLane","doi":"10.1109/GLOCOM.1995.502576","DOIUrl":"https://doi.org/10.1109/GLOCOM.1995.502576","url":null,"abstract":"Efficient series that are used to calculate the probability of error for quadriphase spread, BPSK modulated, synchronous, quasi-synchronous and asynchronous DS-CDMA systems in the presence of chip timing and carrier phase errors are derived. The derivations require the characteristic functions of the multiple access interference and of the self interference. These series are then used to assess the capacity of the systems at different levels of synchronization errors. The derivations are performed for both constant and random synchronization errors. Using the series, the asynchronous quadriphase spread system capacity is compared to that of an asynchronous binary spread system.","PeriodicalId":152724,"journal":{"name":"Proceedings of GLOBECOM '95","volume":"53 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113990259","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: 12
Blind estimation of multiple co-channel digital signals in vector FIR channels 矢量FIR信道中多个同信道数字信号的盲估计
Proceedings of GLOBECOM '95 Pub Date : 1995-11-14 DOI: 10.1109/GLOCOM.1995.500224
Suhas Diggavi, Younggeun Cho, A. Paulraj
{"title":"Blind estimation of multiple co-channel digital signals in vector FIR channels","authors":"Suhas Diggavi, Younggeun Cho, A. Paulraj","doi":"10.1109/GLOCOM.1995.500224","DOIUrl":"https://doi.org/10.1109/GLOCOM.1995.500224","url":null,"abstract":"In this paper we examine the problem of detecting multiple co-channel signals arriving at a sensor array in a dispersive, slowly fading environment. This problem of separating and estimating co-channel signals has recently drawn much attention due to its applications in digital mobile radio. First, we propose a spatio-temporal approach for estimating both the channel and the signals in a delay-spread multipath fading environment. In this approach we exploit the discrete-alphabet property of some of the digital modulation schemes in this algorithm. This algorithm is applicable to an unknown array geometry and propagation environment, and hence it is especially attractive to digital mobile communication applications. Next we examine the matched filter bound for this channel environment. We obtain closed form expressions for the matched filter bound for the single user vector channel. Finally we present some preliminary simulation results to examine the performance of this algorithm and compare it to the single user matched filter bound.","PeriodicalId":152724,"journal":{"name":"Proceedings of GLOBECOM '95","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115060956","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
UWIN-universal wireless infrared network system uwin通用无线红外网络系统
Proceedings of GLOBECOM '95 Pub Date : 1995-11-14 DOI: 10.1109/GLOCOM.1995.502758
D. Medved, Bruno Escojido, Y. Azancot
{"title":"UWIN-universal wireless infrared network system","authors":"D. Medved, Bruno Escojido, Y. Azancot","doi":"10.1109/GLOCOM.1995.502758","DOIUrl":"https://doi.org/10.1109/GLOCOM.1995.502758","url":null,"abstract":"Wireless data communications are being implemented by the complementary technologies of RF and IR. The RF options provide larger area coverage than wireless optical communications but are limited in full bandwidth throughput to about 5 Mbps whereas the infrared systems described in the present paper using IR-LED have achieved data rates up to 125 Mbps. Token ring, Ethernet and PABX (voice) are thus achievable with relatively low cost components at distances up to 400 m for all-weather operations. We present typical case studies of installations for PABX and network building-to-building wireless connectivity locations.","PeriodicalId":152724,"journal":{"name":"Proceedings of GLOBECOM '95","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114377300","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: 1
The importance of bi-directional monitoring to cellular handoff performance 双向监控对蜂窝切换性能的重要性
Proceedings of GLOBECOM '95 Pub Date : 1995-11-14 DOI: 10.1109/GLOCOM.1995.501978
B. Leung
{"title":"The importance of bi-directional monitoring to cellular handoff performance","authors":"B. Leung","doi":"10.1109/GLOCOM.1995.501978","DOIUrl":"https://doi.org/10.1109/GLOCOM.1995.501978","url":null,"abstract":"Handoff control in cellular-based personal communication systems allows a subscriber unit to travel from one cell area to another without service interruption. Previously published handoff studies involve \"balanced\" system scenarios and focus on only the inbound (subscriber unit to base site) or outbound (base site to subscriber unit) link. We point out the inappropriateness of the balanced system assumption for systems that employ directive antennas. We examine the impact of leaving one link uncontrolled and show that a handoff control monitoring both links adapts better to link imbalances inevitable in different regions of the system.","PeriodicalId":152724,"journal":{"name":"Proceedings of GLOBECOM '95","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114207980","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
Implementation of a single multi-task chip: ATDE, XPIC, and DF applicable to multi-level QAM digital radio system 实现单一多任务芯片:ATDE、XPIC和DF，适用于多级QAM数字无线电系统
Proceedings of GLOBECOM '95 Pub Date : 1995-11-14 DOI: 10.1109/GLOCOM.1995.502645
K. Suh, Chang-Yong Park, Dae-Young Lee, Wonchae Kim
{"title":"Implementation of a single multi-task chip: ATDE, XPIC, and DF applicable to multi-level QAM digital radio system","authors":"K. Suh, Chang-Yong Park, Dae-Young Lee, Wonchae Kim","doi":"10.1109/GLOCOM.1995.502645","DOIUrl":"https://doi.org/10.1109/GLOCOM.1995.502645","url":null,"abstract":"The limited frequency resources and the growing demand for high capacity transmission in digital radio systems (DRS) have led to the adoption of multi-level QAM and cochannel operation with cross polarization interference canceler (XPIC). This article describes a powerful multi-task ASIC chip with 165 K gate array for DRS applications. This was implemented on one chip by a state of the art 0.6 /spl mu/m HCMOS technology and designed not only for a complex equalizer and a canceler of up to 256QAM for multipath fading and cochannel operation, but also for a digital filter (DF) for pulse shaping up to 1024QAM or TCM. The superior performance for cochannel DRS with 64QAM is presented by numerical analysis and experimental results.","PeriodicalId":152724,"journal":{"name":"Proceedings of GLOBECOM '95","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114674869","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: 1
Storage- and entropy-constrained multi-stage vector quantization 存储和熵约束的多阶段矢量量化
Proceedings of GLOBECOM '95 Pub Date : 1995-11-14 DOI: 10.1109/GLOCOM.1995.501969
Wen-Jyi Hwang, Yen-Liang Chen, Yu-Chu Chang
{"title":"Storage- and entropy-constrained multi-stage vector quantization","authors":"Wen-Jyi Hwang, Yen-Liang Chen, Yu-Chu Chang","doi":"10.1109/GLOCOM.1995.501969","DOIUrl":"https://doi.org/10.1109/GLOCOM.1995.501969","url":null,"abstract":"A design algorithm for a new multistage vector quantizer, called storageand entropy-constrained multi-stage vector quantizer (SECMSVQ), is presented. In SECMSVQ, the rate constraint at each stage of the vector quantizer (VQ), and the storage size of the whole VQ are specified independently before the design. A dynamic programming technique is then used to allocate the storage size to each stage of the VQ optimally so that the quantization distortion of the VQ is minimized. The SECMSVQ, in addition to being able to control the rate and storage size independently, has the property of progressive image transmission (PIT). Simulation results show that SECMSVQ can be used effectively to implement both the signal compression systems and PIT systems.","PeriodicalId":152724,"journal":{"name":"Proceedings of GLOBECOM '95","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116735920","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
Performance of multiple-symbol differential detection in a non-linear satellite channel 非线性卫星信道中多符号差分检测的性能
Proceedings of GLOBECOM '95 Pub Date : 1995-11-14 DOI: 10.1109/GLOCOM.1995.502692
P. Olsen, C. Elia
{"title":"Performance of multiple-symbol differential detection in a non-linear satellite channel","authors":"P. Olsen, C. Elia","doi":"10.1109/GLOCOM.1995.502692","DOIUrl":"https://doi.org/10.1109/GLOCOM.1995.502692","url":null,"abstract":"The objective is to study the performance of multiple-symbol differential detection (MSDD) in a typical nonlinear satellite channel. The point of interest is to investigate if the phase and amplitude distortion of a typical satellite transponder would prove to be critical for the usage of the MSDD scheme for satellite applications. The investigation is done by means of simulations, and the results are encouraging in the sense that the nonlinear channel poses no special difficulties for the scheme. At the optimal working point (saturation), the loss with respect to the linear channel is approximately 1 dB at BER=1.0e-3 and BER=1.0e-4, whereas the gain which is achieved by increasing the size of the decision vector is the same for the linear and the nonlinear channels.","PeriodicalId":152724,"journal":{"name":"Proceedings of GLOBECOM '95","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116856410","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: 1
Preemptive detection of failure in telephone networks 电话网络故障的先发制人检测
Proceedings of GLOBECOM '95 Pub Date : 1995-11-14 DOI: 10.1109/GLOCOM.1995.502725
B. Silver, M. Moghe, E. Eichen, J. Doleac, R. Bhatnagar, Zhaogang Qian, H. Wan, D. Brooks
{"title":"Preemptive detection of failure in telephone networks","authors":"B. Silver, M. Moghe, E. Eichen, J. Doleac, R. Bhatnagar, Zhaogang Qian, H. Wan, D. Brooks","doi":"10.1109/GLOCOM.1995.502725","DOIUrl":"https://doi.org/10.1109/GLOCOM.1995.502725","url":null,"abstract":"We describe TCAF, an expert system that performs 24-hour monitoring and surveillance of the customer access facilities (CAF) in GTE's telephone network. TCAF is able to identify a large variety of problems, ranging from a fault in a customer's phone to a cut in a large cable. The system is currently being deployed, and initial results show it to be 3-10 times more accurate, and more automated, than the methodologies currently employed by local exchange carriers.","PeriodicalId":152724,"journal":{"name":"Proceedings of GLOBECOM '95","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115285617","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
Implementation of a low delay modified CELP coder at 4.8 kb/s 实现4.8 kb/s的低延迟改进CELP编码器
Proceedings of GLOBECOM '95 Pub Date : 1995-11-14 DOI: 10.1109/GLOCOM.1995.500297
Jian Zhang, Hong-Shen Wang, Tian-Hu Yu
{"title":"Implementation of a low delay modified CELP coder at 4.8 kb/s","authors":"Jian Zhang, Hong-Shen Wang, Tian-Hu Yu","doi":"10.1109/GLOCOM.1995.500297","DOIUrl":"https://doi.org/10.1109/GLOCOM.1995.500297","url":null,"abstract":"This paper presents a low delay high quality speech coder at low bit rates. The configuration of the speech coder is mainly composed of a formant filter, a pitch codebook, an excitation joint codebook, and post enhancement filters. The algorithm of the speech coder is briefly described. Two versions of the speech coder have been implemented in real-time with a single: ADSP-21020 chip. Both objective measurement and informal subjective listening tests show that the proposed speech coder has high quality performance.","PeriodicalId":152724,"journal":{"name":"Proceedings of GLOBECOM '95","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123220773","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
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