Pub Date : 1997-09-09DOI: 10.1109/ICICS.1997.652062
G. Noone, Kaidi Hui, S. Howard
In the field of signal processing and communications, many time series are period M, discrete and noisy in nature. Not only do we often want to accurately estimate the M parameters of such a digital signal, we also require to learn the "firing sequence" of the parameters so that we can predict the next event in time. This is achieved by combining two neural nets. The first net clusters on the time difference between successive events to accurately estimate the parameters and the second net learns to predict which parameter is to be next in the sequence. Hence we are effectively able to track a period M discrete time series. This neural method, in general, requires only a few complete frames or cycles of the time series in order to converge, even for complicated sequences.
{"title":"Tracking period M discrete time series","authors":"G. Noone, Kaidi Hui, S. Howard","doi":"10.1109/ICICS.1997.652062","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652062","url":null,"abstract":"In the field of signal processing and communications, many time series are period M, discrete and noisy in nature. Not only do we often want to accurately estimate the M parameters of such a digital signal, we also require to learn the \"firing sequence\" of the parameters so that we can predict the next event in time. This is achieved by combining two neural nets. The first net clusters on the time difference between successive events to accurately estimate the parameters and the second net learns to predict which parameter is to be next in the sequence. Hence we are effectively able to track a period M discrete time series. This neural method, in general, requires only a few complete frames or cycles of the time series in order to converge, even for complicated sequences.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"1 1","pages":"674-678 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73726655","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 : 1997-09-09DOI: 10.1109/ICICS.1997.647090
Lan Chen, S. Yoshida, H. Murata, S. Hirose
Personal communications systems are increasingly required to accommodate not only voice traffic, but also various types of data traffic. Generally speaking, voice traffic is symmetric between the uplink and downlink, while data traffic can be highly asymmetric. It is therefore inefficient to accommodate data in a conventional TDMA/TDD system with a fixed TDD boundary. In this paper, focusing on continuous data traffic which requires multi-slots in a circuit based TDMA/TDD system, we propose an algorithm in which the TDD boundaries are moved adaptively to accommodate data traffic efficiently. Compared with the conventional fixed boundary algorithm, computer simulations confirm that the proposed algorithm has a superior performance in the excessive transmission delay of data while maintaining the performance of voice. Moreover, an almost similar performance improvement of the proposed algorithm is confirmed for two different average message sizes of data calls.
{"title":"A dynamic channel assignment algorithm for asymmetric traffic in voice/data integrated TDMA/TDD mobile radio","authors":"Lan Chen, S. Yoshida, H. Murata, S. Hirose","doi":"10.1109/ICICS.1997.647090","DOIUrl":"https://doi.org/10.1109/ICICS.1997.647090","url":null,"abstract":"Personal communications systems are increasingly required to accommodate not only voice traffic, but also various types of data traffic. Generally speaking, voice traffic is symmetric between the uplink and downlink, while data traffic can be highly asymmetric. It is therefore inefficient to accommodate data in a conventional TDMA/TDD system with a fixed TDD boundary. In this paper, focusing on continuous data traffic which requires multi-slots in a circuit based TDMA/TDD system, we propose an algorithm in which the TDD boundaries are moved adaptively to accommodate data traffic efficiently. Compared with the conventional fixed boundary algorithm, computer simulations confirm that the proposed algorithm has a superior performance in the excessive transmission delay of data while maintaining the performance of voice. Moreover, an almost similar performance improvement of the proposed algorithm is confirmed for two different average message sizes of data calls.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"52 1","pages":"215-219 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73026174","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 : 1997-09-09DOI: 10.1109/ICICS.1997.647073
Je-Chan Kim, Kee-Sung Cho, Yoon-Ju Lee
QAM (quadrature amplitude modulation) is a very effective technique to achieve a high bit rate transmission without increasing the bandwidth. However, a high precision for fading compensation is required because information resides in both the amplitude and phase components of the QAM modulated signal. In this paper, trellis coded star 16-QAM with diversity and fading compensation in a Rayleigh fading channel is evaluated. The simulation result shows that the trellis coding and diversity largely improve the BER performance of the system. The proposed system has an improvement of about 23.5 dB over 16-QAM only fading compensation. A diversity gain of 18.5 dB and trellis coding gain of 5 dB at BER=10/sup -4/ can be obtained.
{"title":"Performance of trellis coded star 16-QAM with diversity in Rayleigh fading channel","authors":"Je-Chan Kim, Kee-Sung Cho, Yoon-Ju Lee","doi":"10.1109/ICICS.1997.647073","DOIUrl":"https://doi.org/10.1109/ICICS.1997.647073","url":null,"abstract":"QAM (quadrature amplitude modulation) is a very effective technique to achieve a high bit rate transmission without increasing the bandwidth. However, a high precision for fading compensation is required because information resides in both the amplitude and phase components of the QAM modulated signal. In this paper, trellis coded star 16-QAM with diversity and fading compensation in a Rayleigh fading channel is evaluated. The simulation result shows that the trellis coding and diversity largely improve the BER performance of the system. The proposed system has an improvement of about 23.5 dB over 16-QAM only fading compensation. A diversity gain of 18.5 dB and trellis coding gain of 5 dB at BER=10/sup -4/ can be obtained.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"11 1","pages":"133-137 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75312250","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 : 1997-09-09DOI: 10.1109/ICICS.1997.652241
P. Kam, K. Chua, Xiaofeng Yu
We propose an adaptive symbol-by-symbol receiver for phase shift-keying (PSK) over the Gaussian channel with unknown carrier phase. The statistical properties of the carrier phase are assumed unknown to the receiver, other than the fact that it is slowly varying so that a piecewise-constant approximation can be made. The coherent reference for detection is obtained using a first-order filter whose gain is adapted on-line, based on the received signal samples. The performance of the receiver is analyzed both via analysis and simulations.
{"title":"Adaptive symbol-by-symbol reception of PSK on channels with unknown phase","authors":"P. Kam, K. Chua, Xiaofeng Yu","doi":"10.1109/ICICS.1997.652241","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652241","url":null,"abstract":"We propose an adaptive symbol-by-symbol receiver for phase shift-keying (PSK) over the Gaussian channel with unknown carrier phase. The statistical properties of the carrier phase are assumed unknown to the receiver, other than the fact that it is slowly varying so that a piecewise-constant approximation can be made. The coherent reference for detection is obtained using a first-order filter whose gain is adapted on-line, based on the received signal samples. The performance of the receiver is analyzed both via analysis and simulations.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"12 1","pages":"1493-1495 vol.3"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75045319","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 : 1997-09-09DOI: 10.1109/ICICS.1997.652287
T. Willink
The success of beyond-line-of-sight HF data communications is dependent on the characteristics of the ionospheric medium. At high latitudes, these characteristics typically change rapidly with time. This paper describes the static and dynamic characteristics of two high latitude links, one sub-auroral and one trans-auroral. These results have important implications for the design of data modems and, automatic link establishment techniques.
{"title":"Characteristics of ionospheric propagation at high latitudes and their impact on communications systems","authors":"T. Willink","doi":"10.1109/ICICS.1997.652287","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652287","url":null,"abstract":"The success of beyond-line-of-sight HF data communications is dependent on the characteristics of the ionospheric medium. At high latitudes, these characteristics typically change rapidly with time. This paper describes the static and dynamic characteristics of two high latitude links, one sub-auroral and one trans-auroral. These results have important implications for the design of data modems and, automatic link establishment techniques.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"24 1","pages":"1709-1713 vol.3"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75095850","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 : 1997-09-09DOI: 10.1109/ICICS.1997.652215
Wei-rong Chen, Qing-quan Qian, Xiao-Ru Wang
This paper proposes a novel approach to detect and identify transient fault signals. Because the fault signals are non-stationary transient ones, the traditional signal analysis methods, such as the FFT, are not so efficient and useful for fault signal detection. A wavelet neural network (WNN) is used to extract the signal features, and then a feedforward neural network (FNN) is used to identify and classify these features to detect the fault signals. The simulation shows that this method is suitable for application of transient fault detection.
{"title":"Wavelet neural network based transient fault signal detection and identification","authors":"Wei-rong Chen, Qing-quan Qian, Xiao-Ru Wang","doi":"10.1109/ICICS.1997.652215","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652215","url":null,"abstract":"This paper proposes a novel approach to detect and identify transient fault signals. Because the fault signals are non-stationary transient ones, the traditional signal analysis methods, such as the FFT, are not so efficient and useful for fault signal detection. A wavelet neural network (WNN) is used to extract the signal features, and then a feedforward neural network (FNN) is used to identify and classify these features to detect the fault signals. The simulation shows that this method is suitable for application of transient fault detection.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"39 1","pages":"1377-1381 vol.3"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77369419","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 : 1997-09-09DOI: 10.1109/ICICS.1997.647045
S. Tan
This simple channel simulation program is written using MATLAB to determine the influence of phase nonlinearity distortions on the bit error rate performance of BPSK signals transmitted through a satellite transponder and its ground station receiver. For simplicity, the channel is modelled as a cascade of two filters found in the IF section of the satellite transponder and ground station receiver. Coherent (synchronous) detection of the BPSK signal in the ground station receiver is assumed and the binary data is recovered using a sampling and threshold decision device. This simulation method has been applied to the UoSAT-12's Merlion bent-pipe transponder designed for 1 Mb/s BPSK data transmissions.
{"title":"Simulation of phase nonlinearity effects in a satellite channel","authors":"S. Tan","doi":"10.1109/ICICS.1997.647045","DOIUrl":"https://doi.org/10.1109/ICICS.1997.647045","url":null,"abstract":"This simple channel simulation program is written using MATLAB to determine the influence of phase nonlinearity distortions on the bit error rate performance of BPSK signals transmitted through a satellite transponder and its ground station receiver. For simplicity, the channel is modelled as a cascade of two filters found in the IF section of the satellite transponder and ground station receiver. Coherent (synchronous) detection of the BPSK signal in the ground station receiver is assumed and the binary data is recovered using a sampling and threshold decision device. This simulation method has been applied to the UoSAT-12's Merlion bent-pipe transponder designed for 1 Mb/s BPSK data transmissions.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"19 1","pages":"1-4 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80049974","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 : 1997-09-09DOI: 10.1109/ICICS.1997.652110
Yong-Hack Lee, Suh-Hyun Cheon
In a parallel graph reduction system, speculative evaluation can increase parallelism but waste machine resources by evaluating an expression which may eventually be discarded. When a speculative task reduces a lambda expression to WHNF (weak head normal form), substitution can lead to unbounded growth of the graph size and require a copy operation. This speculative task may be unnecessary. In that case the performance is affected by the overheads to terminate all tasks to be propagated from a speculative task and to refresh the memory cells to be allocated for the copy operation. We propose a lambda form called DSF (deferred substitution form) in which substitution is deferred until a mandatory task evaluates the substitution. In a speculative task to the DSF, since there is no substitution, it cannot grow the graph size and require a copy operation. Therefore the overhead can be decreased when a expression reduced to the DSF is eventually unnecessary. In addition we propose an evaluation model for the DSF to increase the parallelism.
{"title":"Speculative parallel graph reduction for lambda calculus","authors":"Yong-Hack Lee, Suh-Hyun Cheon","doi":"10.1109/ICICS.1997.652110","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652110","url":null,"abstract":"In a parallel graph reduction system, speculative evaluation can increase parallelism but waste machine resources by evaluating an expression which may eventually be discarded. When a speculative task reduces a lambda expression to WHNF (weak head normal form), substitution can lead to unbounded growth of the graph size and require a copy operation. This speculative task may be unnecessary. In that case the performance is affected by the overheads to terminate all tasks to be propagated from a speculative task and to refresh the memory cells to be allocated for the copy operation. We propose a lambda form called DSF (deferred substitution form) in which substitution is deferred until a mandatory task evaluates the substitution. In a speculative task to the DSF, since there is no substitution, it cannot grow the graph size and require a copy operation. Therefore the overhead can be decreased when a expression reduced to the DSF is eventually unnecessary. In addition we propose an evaluation model for the DSF to increase the parallelism.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"47 19 1","pages":"903-906 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79160934","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 : 1997-09-09DOI: 10.1109/ICICS.1997.647121
I. Kim, Young-Wook Cha, K. Lee
ATM technology-based B-ISDN is widely accepted as the next generation high speed communication system. An ATM customer network can be built as a star, bus, or ring topology. However, the main focus of the ATM access network has been the star topology where multiple terminals within the customer network are concentrated on an ATM switch. The demands of residential or small business subscribers have resulted in the need to build an ATM customer network gradually and economically, which can introduce the emerging new multimedia services. A shared medium-based multiaccess technology cannot only allow switches to be smaller but also improve the switch port granularity. It is even possible to connect multiple terminals without an initial need for an expensive ATM switch. In this paper, by considering a multiaccess customer network architecture, we present call and connection control schemes that will play a key role in the feasibility of the multiaccess ATM customer network.
{"title":"Call and connection control on multiaccess ATM customer network","authors":"I. Kim, Young-Wook Cha, K. Lee","doi":"10.1109/ICICS.1997.647121","DOIUrl":"https://doi.org/10.1109/ICICS.1997.647121","url":null,"abstract":"ATM technology-based B-ISDN is widely accepted as the next generation high speed communication system. An ATM customer network can be built as a star, bus, or ring topology. However, the main focus of the ATM access network has been the star topology where multiple terminals within the customer network are concentrated on an ATM switch. The demands of residential or small business subscribers have resulted in the need to build an ATM customer network gradually and economically, which can introduce the emerging new multimedia services. A shared medium-based multiaccess technology cannot only allow switches to be smaller but also improve the switch port granularity. It is even possible to connect multiple terminals without an initial need for an expensive ATM switch. In this paper, by considering a multiaccess customer network architecture, we present call and connection control schemes that will play a key role in the feasibility of the multiaccess ATM customer network.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"24 1","pages":"367-372 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81582752","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}
In this paper, we propose a new type of gateway for WWW-Oracle interface, called ORAWIS (ORAcle Web Interface System). It supports various types of relational queries on the WWW such as join between two tables, one level nested queries, ORDER BY and GROUP BY operations in a conditional clause. In addition, a application designer can suggest an access method for a table by query selection with a hint option on the WWW. It causes the Oracle optimizer to choose the specified access path. By this function, an application designer can choose more efficient way than the optimizer can determine. The designer can also check the execution time of the SQL statement on the WWW.
在本文中，我们提出了一种用于WWW-Oracle接口的新型网关，称为ORAWIS (ORAcle Web interface System)。它支持WWW上各种类型的关系查询，例如两个表之间的连接、一级嵌套查询、条件子句中的ORDER BY和GROUP BY操作。此外，应用程序设计人员可以在WWW上通过带有提示选项的查询选择来建议表的访问方法。它使Oracle优化器选择指定的访问路径。通过这个函数，应用程序设计人员可以选择比优化器所能确定的更有效的方法。设计者还可以在WWW上查看SQL语句的执行时间。
{"title":"An extended model for integration between the Oracle DBMS and WWW","authors":"Gi-Hwa Jang, Hyeonjeong Mun, Sooho Ok, Yong-Tae Woo","doi":"10.1109/ICICS.1997.647163","DOIUrl":"https://doi.org/10.1109/ICICS.1997.647163","url":null,"abstract":"In this paper, we propose a new type of gateway for WWW-Oracle interface, called ORAWIS (ORAcle Web Interface System). It supports various types of relational queries on the WWW such as join between two tables, one level nested queries, ORDER BY and GROUP BY operations in a conditional clause. In addition, a application designer can suggest an access method for a table by query selection with a hint option on the WWW. It causes the Oracle optimizer to choose the specified access path. By this function, an application designer can choose more efficient way than the optimizer can determine. The designer can also check the execution time of the SQL statement on the WWW.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"16 1","pages":"569-572 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81740390","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：