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The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.最新文献

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On the capacity of multicode and variable spreading gain access scheme for multicarrier CDMA systems supporting multirate services with transmit power control 支持发射功率控制多速率业务的多载波CDMA系统的多码和可变扩展增益接入方案的容量研究
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004. Pub Date : 2004-11-30 DOI: 10.1109/ICCS.2004.1359461
Xiaoyu Hu, Y. Chew
{"title":"On the capacity of multicode and variable spreading gain access scheme for multicarrier CDMA systems supporting multirate services with transmit power control","authors":"Xiaoyu Hu, Y. Chew","doi":"10.1109/ICCS.2004.1359461","DOIUrl":"https://doi.org/10.1109/ICCS.2004.1359461","url":null,"abstract":"In this paper, the multicode (mc) and the variable spreading gain (VSG) access schemes for asynchronous multicarrier code division multiple access (MC-CDMA) systems supporting multirate services are considered. The system capacities for these two multirate access schemes are investigated. A transmit power control is proposed to maintain the link quality and improve the system capacity. Simulation results verified the correctness of the theoretical bit-error-rate (BER) performance expressions derived for MC-CDMA systems using these access schemes. Numerical results show that mc access scheme using orthogonal Gold spreading sequences give the best performance, and its superiority increases when the ratio between the data rates of both service class increases. In case when non-orthogonal Gold codes are used, mc access scheme shows a degrading in the system capacity as compared to VSG, due to the presence of larger self-interference (SI) among the sequences used by each high rate user","PeriodicalId":333629,"journal":{"name":"The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122134746","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: 3
Diversity-coding-orthogonality tradeoff for coded MC-CDMA with high level modulation 高电平调制下编码MC-CDMA的分集-编码正交性权衡
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004. Pub Date : 2004-11-30 DOI: 10.1093/ietcom/E88-B.1.76
D. Garg, F. Adachi
{"title":"Diversity-coding-orthogonality tradeoff for coded MC-CDMA with high level modulation","authors":"D. Garg, F. Adachi","doi":"10.1093/ietcom/E88-B.1.76","DOIUrl":"https://doi.org/10.1093/ietcom/E88-B.1.76","url":null,"abstract":"In MC-CDMA, the data rate can be increased by reducing the spreading factor SF or by allowing multicode transmission. In this paper, we evaluate by computer simulations which gives a better bit error rate (BER) performance lower SF or multicode operation - when high level modulation is used in addition to error control coding. For a coded system in a frequency selective channel, there is a tradeoff between frequency diversity gain due to the spreading of symbols, coding gain due to better frequency interleaving effect and orthogonality destruction. It is shown that for QPSK, the performance of OFDM (MC-CDMA with SF=1) is almost the same as that of a fully spread MC-CDMA system. However, for 16QAM and 64QAM, the BER performance is better for lower SF unlike the uncoded system, wherein higher SF gives a better BER","PeriodicalId":333629,"journal":{"name":"The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116836565","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: 10
A pseudo base station based algorithm for power aware routing in UWB ad hoc networks 一种基于伪基站的超宽带自组网功率感知路由算法
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004. Pub Date : 2004-11-30 DOI: 10.1109/ICCS.2004.1359328
Inhee Oh, Jinho Choi
{"title":"A pseudo base station based algorithm for power aware routing in UWB ad hoc networks","authors":"Inhee Oh, Jinho Choi","doi":"10.1109/ICCS.2004.1359328","DOIUrl":"https://doi.org/10.1109/ICCS.2004.1359328","url":null,"abstract":"The battery life of mobile hosts is one of important performance indicators in ad hoc networks because networks rely on each host's battery power. In this paper, we propose a battery-life-aware routing in ultra-wideband (UWB) ad hoc networks. The proposed routing method saves significant power in broadcasting process by leveraging a fixed wired device's power. Simulation results reveal that the proposed scheme provides good performance by using a pseudo base station and saves the power of wireless hosts up to 50%","PeriodicalId":333629,"journal":{"name":"The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132029066","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
Optimum design of parallel coupled-line filters 并联耦合线滤波器的优化设计
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004. Pub Date : 2004-11-30 DOI: 10.1109/ICCS.2004.1359395
H. Oraizi, M. Moradian, K. Hirasawa
{"title":"Optimum design of parallel coupled-line filters","authors":"H. Oraizi, M. Moradian, K. Hirasawa","doi":"10.1109/ICCS.2004.1359395","DOIUrl":"https://doi.org/10.1109/ICCS.2004.1359395","url":null,"abstract":"In this paper, a design and optimization procedure based on the method of least squares is presented for edge-coupled or parallel coupled-line filters, with impedance matching of arbitrary source and load impedances. An error function is constructed for the implementation of specified insertion loss in the passband and return loss in the stopband, based on the even- and odd-mode theory using the impedance, transmission and scattering matrices. The minimization of error function is performed with respect to the lengths, widths and gap spacings of lines, which determines the filter configuration. Computer implementation of the proposed method, comparison with the available full-wave analysis softwares, fabrication, and testing of sample filters, indicate the ease of application and advantages of the proposed method over the other methods (such as impedance matching, increasing bandwidth, and ease of computer implementation)","PeriodicalId":333629,"journal":{"name":"The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129034996","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
Cooperative diversity in space-time coded wireless networks 时空编码无线网络中的协同分集
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004. Pub Date : 2004-11-30 DOI: 10.1109/ICCS.2004.1359370
J. Vazifehdan, H. Shafiee
{"title":"Cooperative diversity in space-time coded wireless networks","authors":"J. Vazifehdan, H. Shafiee","doi":"10.1109/ICCS.2004.1359370","DOIUrl":"https://doi.org/10.1109/ICCS.2004.1359370","url":null,"abstract":"The use of spatial diversity methods is an effective way to counter the adverse effects of fading in wireless channels. Cooperative networks aim to utilize the available terminals as a collection of distributed antennas for the transmission of signals from one end of the network to the other. This technique is especially effective in providing spatial diversity when having more than one antenna in the transmitter and/or receiver is not practical or cost-effective. Even with multiple antennas available, cooperation amongst terminals could provide additional spatial diversity. In this paper, we investigate a cooperative strategy, in which the transmitter uses a block space-time code. Here, one or more terminals can be designated as partner stations which either re-transmit their received signal after simple amplification or after appropriate processing. We obtain analytical expressions for the error rate performance of the systems considered. Analytical and simulation results show that the added spatial diversity achieved improves the error rate performance of the system quite remarkably","PeriodicalId":333629,"journal":{"name":"The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.","volume":"209 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125387786","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: 6
On implementation of link adaption in OFDM wireless networks OFDM无线网络中链路自适应的实现
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004. Pub Date : 2004-11-30 DOI: 10.1109/ICCS.2004.1359366
Yap Kok Kiong, M. Motani
{"title":"On implementation of link adaption in OFDM wireless networks","authors":"Yap Kok Kiong, M. Motani","doi":"10.1109/ICCS.2004.1359366","DOIUrl":"https://doi.org/10.1109/ICCS.2004.1359366","url":null,"abstract":"The popularity of wireless networks has soared in recent years. The wireless channel, along with its many benefits, poses a host of challenges for system designers, due to its time-varying and frequency selective behavior. Orthogonal frequency division multiplexing (OFDM) addresses some of these challenges at the physical layer. In this paper, we discuss various issues in a practical implementation of an OFDM based system which supports adaptive modulation. A novel blind scheme for detecting inactive carriers, resulting from water-filling or other adaptive modulation, is proposed and investigated. Extensive simulation of the detection scheme, in an IEEE 802.11a framework, shows it to be robust against changes in code rate, data modulation and water-level. Backward compatibility of the new scheme with existing devices is also discussed and detection of new devices at the system level is suggested and described. Overall, the work in this paper forms the basis for a cross-layer approach to the optimization of wireless networks, in which the physical, link and network layers are adapted to system parameters such as buffer state, traffic statistics, and channel conditions","PeriodicalId":333629,"journal":{"name":"The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122182172","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 scalable hardware solution for packet classification 数据包分类的可扩展硬件解决方案
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004. Pub Date : 2004-11-30 DOI: 10.1109/ICCS.2004.1359435
Hung-Yi Chang, Chia-Tai Chan, Pi-Chung Wang, Chun-Liang Lee
{"title":"A scalable hardware solution for packet classification","authors":"Hung-Yi Chang, Chia-Tai Chan, Pi-Chung Wang, Chun-Liang Lee","doi":"10.1109/ICCS.2004.1359435","DOIUrl":"https://doi.org/10.1109/ICCS.2004.1359435","url":null,"abstract":"One of interesting hardware solutions proposed to solve the packet classification problem is bit-vector algorithm. Different from other hardware solutions such as ternary CAM, it efficiently utilizes the memories to achieve an excellent performance in medium size policy database; however, it cannot scale up with the policy number increases. In this paper, we proposed an improved bit-vector algorithm named bit vector condensation, which can be adapted to large policy databases. Experiments showed that our proposed algorithm drastically improves in the storage requirements and search speed as compared to the original algorithm","PeriodicalId":333629,"journal":{"name":"The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131221885","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
A novel channel estimator for turbo decoding in stationary and non-stationary flat fading channel 一种用于平稳和非平稳平滑衰落信道turbo译码的信道估计器
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004. Pub Date : 2004-11-30 DOI: 10.1109/ICCS.2004.1359411
Wee-Peng Ang, H. Garg
{"title":"A novel channel estimator for turbo decoding in stationary and non-stationary flat fading channel","authors":"Wee-Peng Ang, H. Garg","doi":"10.1109/ICCS.2004.1359411","DOIUrl":"https://doi.org/10.1109/ICCS.2004.1359411","url":null,"abstract":"A new and efficient fast Fourier transform (FFT) channel estimation filter with an integrated fading rate calculator is developed for turbo decoding in a flat fading channel. It removes the need for a-priori knowledge of the channel fading rate for good performance which is a key requirement in many filters in the existing literatures. Under both time-invariant and time-varying fading rate, it achieves BER performance close to the optimum Wiener filter with a lower computational count","PeriodicalId":333629,"journal":{"name":"The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127791186","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
The effect of noise estimation error in the LDPC decoding performance 噪声估计误差对LDPC译码性能的影响
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004. Pub Date : 2004-11-30 DOI: 10.1109/ICCS.2004.1359421
In-Ki Lee, Sang-jin Park, Ji-Won Jung, Eun-A Choi, Nae-Soo Kirn, Duk-Gil Oh
{"title":"The effect of noise estimation error in the LDPC decoding performance","authors":"In-Ki Lee, Sang-jin Park, Ji-Won Jung, Eun-A Choi, Nae-Soo Kirn, Duk-Gil Oh","doi":"10.1109/ICCS.2004.1359421","DOIUrl":"https://doi.org/10.1109/ICCS.2004.1359421","url":null,"abstract":"The number of quantization bits of the input signals rn needs to be optimally determined through the trade-off between the H/W complexity and the BER performance in LDPC codes applications. Also, an effective means to incorporate a channel reliability Lc in the log-MAP based LDPC decoding is highly required, because it has a major effect on both the complexity and performance. In this paper so as to effectively incorporate Lc in LDPC decoding. The optimal number of quantization bits of rn is investigated through Monte-Carlo simulations assuming that bit-shifting approach is adopted. In addition, the effects of an incorrect estimation of noise variance on the performance of LDPC codes are investigated. There is a confined range in which the effects of an in correct estimation can be ignored","PeriodicalId":333629,"journal":{"name":"The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132594648","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
Multistage detection for OFDM signals under phase noise 相位噪声下OFDM信号的多级检测
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004. Pub Date : 2004-11-30 DOI: 10.1109/ICCS.2004.1359353
Q. Quan
{"title":"Multistage detection for OFDM signals under phase noise","authors":"Q. Quan","doi":"10.1109/ICCS.2004.1359353","DOIUrl":"https://doi.org/10.1109/ICCS.2004.1359353","url":null,"abstract":"In orthogonal frequency-division multiplexing (OFDM) transmission system, phase noise from oscillator instabilities in the receiver is a potentially serious problem, especially when bandwidth efficient, high order signal constellations are employed. There are two carrier phase noise effects in the OFDM receiver. One is the common phase error (CPE) which is caused by the own carrier phase noise, another is the inter carrier interference (ICI) which is caused by the phase noise of all other carriers. The orthogonality of the sub-carriers has been broken due to the ICL So the conventional detection implemented by an FFT and a decision is not the good choice. The optimum detection is based on maximum likelihood sequence estimation. But the computational complexity of the optimum detection depends exponentially on the number of sub-carriers. Multistage detection for OFDM signals is proposed in this paper. The computational complexity of the multistage detection is linear in the number of sub-carriers. The performance of the multistage detection is compared with that of the optimum detection. Some simulation results show that the proposed multistage detection improves BER remarkably under the heavy carrier phase noise circumstances","PeriodicalId":333629,"journal":{"name":"The Ninth International Conference onCommunications Systems, 2004. ICCS 2004.","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130376536","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
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