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IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)最新文献

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A novel stochastic rough-surface scattering representation for ray-optical wave propagation modelling 射线光波传播模型中一种新的随机粗糙表面散射表示
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211) Pub Date : 2001-10-07 DOI: 10.1109/VTC.2001.956507
D. Didascalou, J. Maurer, W. Wiesbeck
{"title":"A novel stochastic rough-surface scattering representation for ray-optical wave propagation modelling","authors":"D. Didascalou, J. Maurer, W. Wiesbeck","doi":"10.1109/VTC.2001.956507","DOIUrl":"https://doi.org/10.1109/VTC.2001.956507","url":null,"abstract":"A new method to include stochastic rough surface scattering into deterministic ray-optical wave propagation modelling is derived. It can be utilized in conjunction with the concept of ray launching. Similar to the Kirchhoff formulations, the approach is based on a tangential plane approximation, i.e. it is applicable to surfaces with gentle undulations, whose horizontal dimensions are large compared to the incident wavelength. However, in contrast to the Kirchhoff models, which are only valid for either slightly rough or very rough surfaces, the proposed stochastic scattering approach includes both the coherent and incoherent components at the same time. The purely deterministic ray-based modelling is expanded by a \"stochastic\" component, allowing for the first time to account for non-deterministic scattering in ray-optical wave propagation modelling.","PeriodicalId":129008,"journal":{"name":"IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130063205","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
A perfectly stable contention access scheme for wireless access networks 一种完全稳定的无线接入网争用接入方案
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211) Pub Date : 2001-10-07 DOI: 10.1109/VTC.2001.957127
M. Yuang, B. C. Lo, Ju-Ya Chen
{"title":"A perfectly stable contention access scheme for wireless access networks","authors":"M. Yuang, B. C. Lo, Ju-Ya Chen","doi":"10.1109/VTC.2001.957127","DOIUrl":"https://doi.org/10.1109/VTC.2001.957127","url":null,"abstract":"Existing TDM-based contention access schemes exhibit the unstable or load-susceptible problem in which throughput exponentially deteriorates as the traffic offered load increases or fluctuates. In this paper, we propose a persistently stable, efficient hexanary-feedback-based contention access (HFCA) scheme, aiming to provide QoS guarantee while retaining stable and maximal network throughput. Unlike existing schemes that consider all contending mobile terminals as a whole, HFCA incrementally resolves a small group of terminals each time via a two-phase selection/resolution process. The incremental resolution repeats until the minimum non-blocking probability (QoS for signaling traffic) is satisfied. To accelerate resolution within the process, the number of simultaneously transmitting terminals is estimated based on an envelope-pdf-based estimator (EPER), by matching the corresponding normalized envelope histogram of the receiving signal with the priori envelope-pdf library. Facilitated with incremental resolution and the EPER, HFCA achieves the highest maximum throughput (0.574) and saturated throughput (0.52) reported to date irrespective of traffic increase and variation.","PeriodicalId":129008,"journal":{"name":"IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129030235","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
Turbo decoder implementation Turbo解码器实现
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211) Pub Date : 2001-10-07 DOI: 10.1109/VTC.2001.956515
Sangho Yoon
{"title":"Turbo decoder implementation","authors":"Sangho Yoon","doi":"10.1109/VTC.2001.956515","DOIUrl":"https://doi.org/10.1109/VTC.2001.956515","url":null,"abstract":"Recently, turbo code has gathered much attention for its outstanding performance. However, its complexity and decoding latency are severe drawbacks. Turbo code has been adopted in the 3GPP specification as one of the channel coding schemes. To implement a turbo decoder compliant with the 3GPP specification, the author adopted the sliding window method and devised a way to simplify the E-function of the MAP algorithm. This paper covers the optimum sliding window size and piecewise-linear E-function. In addition, implementing a scheme using the sliding window algorithm is covered. This focuses on implementing an interleaver and deinterleaver. The turbo decoder described is designed according to the 3GPP specification, and every simulation was done under AWGN.","PeriodicalId":129008,"journal":{"name":"IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129141307","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
Fundamental limitations of power control in W-CDMA W-CDMA中功率控制的基本限制
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211) Pub Date : 2001-10-07 DOI: 10.1109/VTC.2001.956846
Fredrik Gunnarsson
{"title":"Fundamental limitations of power control in W-CDMA","authors":"Fredrik Gunnarsson","doi":"10.1109/VTC.2001.956846","DOIUrl":"https://doi.org/10.1109/VTC.2001.956846","url":null,"abstract":"Power control is considered as an important means to combat near-far fading effects and maintain acceptable connections in wireless communications systems. When applying power control in practice, the performance is restricted by a number of fundamental limitations. Here, these are addressed from a control theory perspective. Limited update rate, limited feedback bandwidth, time delays, measurement errors, feedback errors and filtering effects among other aspects all affect the resulting performance, and are related to radio channel characteristics. Simulations further illustrate the hampering effects.","PeriodicalId":129008,"journal":{"name":"IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133000364","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: 31
Joint power control and source-channel coding for video communication over wireless networks 无线网络视频通信的联合功率控制和源信道编码
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211) Pub Date : 2001-10-07 DOI: 10.1109/VTC.2001.956481
Zhu Ji, Qian Zhang, Wenwu Zhu, Jianhua Lu, Ya-Qin Zhang
{"title":"Joint power control and source-channel coding for video communication over wireless networks","authors":"Zhu Ji, Qian Zhang, Wenwu Zhu, Jianhua Lu, Ya-Qin Zhang","doi":"10.1109/VTC.2001.956481","DOIUrl":"https://doi.org/10.1109/VTC.2001.956481","url":null,"abstract":"Video communication over wireless link is a challenging task due to the time-varying characteristics of a wireless channel and limited battery resource in the handheld devices. This paper proposes a power-optimized approach for video communication, which simultaneously controls the transmission power, source rate and error protection level to minimize the total power consumption for all users. The performance of the cellular CDMA system using our proposed scheme is compared with the one using a fixed power-control scheme. The simulation results show that our proposed joint power control and source-channel coding scheme achieves significant power saving compared to the fixed scheme.","PeriodicalId":129008,"journal":{"name":"IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132070382","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
Adaptive modulation and coding for satellite-UMTS 卫星- umts的自适应调制和编码
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211) Pub Date : 2001-10-07 DOI: 10.1109/VTC.2001.956567
M. Sumanasena, B. Evans
{"title":"Adaptive modulation and coding for satellite-UMTS","authors":"M. Sumanasena, B. Evans","doi":"10.1109/VTC.2001.956567","DOIUrl":"https://doi.org/10.1109/VTC.2001.956567","url":null,"abstract":"An adaptive coding and modulation transmission scheme applicable for third-generation mobile satellite systems is proposed. The transmitter dynamically selects the optimum coding and modulation scheme according to the environment in order to maximize the spectrum and power efficiency. A constant average bit error rate (BER) is maintained without changing (or with a very small change to) the transmitted power, and hence the scheme eases the power control requirements. In addition, a higher throughput can be achieved compared to fixed (non-adaptive) systems. Unlike other adaptive transmission systems, in our work the adaptation is based on the Rice factor. The paper also discusses a Rice factor estimation algorithm.","PeriodicalId":129008,"journal":{"name":"IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130290310","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 TDMA scheme with dynamic frame structure 一种动态框架结构的时分多址方案
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211) Pub Date : 2001-10-07 DOI: 10.1109/VTC.2001.956428
Hongjun Zhang, P. Gburzynski
{"title":"A TDMA scheme with dynamic frame structure","authors":"Hongjun Zhang, P. Gburzynski","doi":"10.1109/VTC.2001.956428","DOIUrl":"https://doi.org/10.1109/VTC.2001.956428","url":null,"abstract":"We present a TDMA-based scheme intended for carrying traffic with diverse QoS requirements in mobile environments. In contrast to other TDMA protocols for mobile applications, instead of trying to fit the offered traffic to the slot size, our solution adapts the slot size to the offered traffic. In consequence, the proposed scheme is more flexible and incurs lower bandwidth overhead than other TDMA-based solutions.","PeriodicalId":129008,"journal":{"name":"IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131328928","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
Experimental study on coexistence of 802.11b with alien devices 802.11b与外来设备共存的实验研究
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211) Pub Date : 2001-10-07 DOI: 10.1109/VTC.2001.956920
J. D. P. Pavon, Sunghyun Choi
{"title":"Experimental study on coexistence of 802.11b with alien devices","authors":"J. D. P. Pavon, Sunghyun Choi","doi":"10.1109/VTC.2001.956920","DOIUrl":"https://doi.org/10.1109/VTC.2001.956920","url":null,"abstract":"Several kinds of wireless communication systems, such as IEEE 802.11, Bluetooth, HomeRF, and cordless telephones, have been developed to run in the 2.4 GHz ISM band. In many cases, these technologies are complementary rather than competing, and are likely to coexist in the same environment. This paper presents experimental results of the coexistence tests among these different systems working in the 2.4 GHz ISM band. The main goal of this work is to determine how the performance of 802.11b is degraded by the existence of such other devices in the neighborhood. This should be the first step towards a better coexistence solution for IEEE 802.11b WLAN in this band.","PeriodicalId":129008,"journal":{"name":"IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125366508","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: 18
Spatio-temporal channel characteristics at 5 GHz in a typical office environment 典型办公环境下5ghz的时空信道特性
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211) Pub Date : 2001-10-07 DOI: 10.1109/VTC.2001.956397
J. Medbø, J. Berg
{"title":"Spatio-temporal channel characteristics at 5 GHz in a typical office environment","authors":"J. Medbø, J. Berg","doi":"10.1109/VTC.2001.956397","DOIUrl":"https://doi.org/10.1109/VTC.2001.956397","url":null,"abstract":"In order to assess important direction-delay indoor propagation characteristics, a combined wideband and 3D spatial channel measurement campaign has been performed in the frequency band 5.1-5.3 GHz (HIPERLAN type 2 band) in a modern office building. Non- line-of-sight (NLOS) measurements in a corridor environment on a single floor and measurements between floors were performed. Joint determination of direction of arrival and distance was obtained by means of maximum likelihood (ML) estimation of the radio channel. The main pathways between the transmitter and receiver were identified from the point source estimates and reconstructed in structural drawings of the building. From the results it can be concluded that both geometrical optics (GO) and diffraction (scattering) are important propagation mechanisms in NLOS indoor scenarios. The cross-floor results show a strong attenuation of the direct wave (25 dB per floor). The total path loss is, however, reduced due to reflection paths from an adjacent building.","PeriodicalId":129008,"journal":{"name":"IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121408662","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: 32
A new code allocation scheme for UMTS system 一种新的UMTS系统码分配方案
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211) Pub Date : 2001-10-07 DOI: 10.1109/VTC.2001.956909
T. Al-Meshhadany, K. A. Agha
{"title":"A new code allocation scheme for UMTS system","authors":"T. Al-Meshhadany, K. A. Agha","doi":"10.1109/VTC.2001.956909","DOIUrl":"https://doi.org/10.1109/VTC.2001.956909","url":null,"abstract":"Third generation wireless system is based on the CDMA access technique. In this technique, all users share the same bandwidth simultaneously but with different codes. This sharing generates interference that can reduce the system's capacity when using a weak code allocation algorithm. We analyze the WCDMA capacity as a function of the type and the number of allocated codes. We also study the method used to assign codes to the users. Finally we propose a new scheme that assigns the code allocation according to the type of user application. Simulation model and results are also provided.","PeriodicalId":129008,"journal":{"name":"IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211)","volume":"34 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123054767","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: 5
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