2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08)最新文献_第4页

Serial equalization structure for channel compensation in OFDM systems OFDM系统中信道补偿的串行均衡结构

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08) Pub Date : 2008-05-05 DOI: 10.1109/WOCN.2008.4542544

M. Mohammadi, M. Ardabilipour, B. Moussakhani, Z. Mobini

{"title":"Serial equalization structure for channel compensation in OFDM systems","authors":"M. Mohammadi, M. Ardabilipour, B. Moussakhani, Z. Mobini","doi":"10.1109/WOCN.2008.4542544","DOIUrl":"https://doi.org/10.1109/WOCN.2008.4542544","url":null,"abstract":"By the advent of equalizers their major focus was to estimate the Channel Impulse Response (CIR). Finding such a transform function, detection of the transmitted data using the inversed CIR is the next step. To eliminate the first step in this paper, we implemented channel equalizers serially in the system. Unlike conventional methods, the proposed scheme estimates Inversed channel Impulse Response directly using adaptive algorithms. Frequency domain channel estimators are common and easy to implement in OFDM based system, but comparing to serial structure presented in this paper they are slow and inaccurate. Also for every one tap equalizer implemented in frequency domain we need one division operator for each FFT point while in proposed structure the filter length is fixed and operates on every data Frame. In this paper for an OFDM based system two channel estimation algorithms (RLS and NLMS) have been implemented using the proposed structure and the promising results have been presented. Moreover, by reducing computational complexity the proposed method also outperforms conventional schemes.","PeriodicalId":363625,"journal":{"name":"2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114919907","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

Multimode interference optical filter for 1.3 and 1.55 μm by using taper structures 1.3和1.55 μm的多模干涉滤光片采用锥形结构

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08) Pub Date : 2008-05-05 DOI: 10.1109/WOCN.2008.4542502

Sekartedjo, A. Hatta

引用次数: 2

Hierarchical survivability model for slotted all-optical packet switching networks 开槽全光分组交换网络的分层生存能力模型

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08) Pub Date : 2008-05-05 DOI: 10.1109/WOCN.2008.4542521

F. Al-Zahrani

引用次数: 3

A fast and efficient crosstalk-free algorithm for routing in optical multistage interconnection networks 一种快速有效的光多级互连网络路由无串扰算法

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08) Pub Date : 2008-05-05 DOI: 10.1109/WOCN.2008.4542518

T. Shahida, M. Othman, M. Khazani

引用次数: 2

A Novel cluster-based routing protocol with extending lifetime for wireless sensor networks 一种基于集群的无线传感器网络路由协议

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08) Pub Date : 2008-05-05 DOI: 10.1109/WOCN.2008.4542499

J. J. Lotf, M.N. Bonab, S. Khorsandi

引用次数: 65

Cross-layer optimization performance evaluation of OFDM broadband network on millimeter wave channels 毫米波信道OFDM宽带网络跨层优化性能评价

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08) Pub Date : 2008-05-05 DOI: 10.1109/WOCN.2008.4542512

Endroyono, G. Hendrantoro

{"title":"Cross-layer optimization performance evaluation of OFDM broadband network on millimeter wave channels","authors":"Endroyono, G. Hendrantoro","doi":"10.1109/WOCN.2008.4542512","DOIUrl":"https://doi.org/10.1109/WOCN.2008.4542512","url":null,"abstract":"The need of bandwidth in high speed data and multimedia services of Broadband Wireless System means the need of occupying higher frequency band. LMDS is an example of broadband access system operated in EHF millimeter band (e.g. 30 GHz). In millimeter band, the capacity of wireless network will have two major constrains: the impact of millimeter wave channels in physical layer and the channel access method in MAC layer. Improvement in physical layer is usually carried-out by adaptive modulation considering channel state information (CSI). In MAC layer, many adaptive scheduling have also been developed. Combining these two approaches result in many algorithms called cross layer optimization in wireless network. This paper present our first step of evaluation of cross layer optimization performance of orthogonal frequency division multiplexing (OFDM) network applied in millimeter wave channels in tropical region. Based on measurement and related channels data in Surabaya Indonesia, we found that 'rain attenuation', could reach the level 70 dB in the long period of time. Simulation shows the impact of the severity of 'rain channel', i.e. degrade overall throughput or decreases the feasible rate of system. To compensate the degradation by channels and to provide maximum capacity, considering fairness among users, an evaluation of resource allocation via simulation of cross-layer optimization of OFDM Wireless Network in tropical region on millimeter wave channels is being carried out.","PeriodicalId":363625,"journal":{"name":"2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128256132","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

Implementation of differential precoder for high-speed optical DQPSK modulation 高速光DQPSK调制差分预编码器的实现

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08) Pub Date : 2008-05-05 DOI: 10.1109/WOCN.2008.4542504

P. Yue, A. Wen, Tao Shang, Chengwei Wang

引用次数: 6

Optical orthogonal frequency division multiplexing for high speed wireless optical communications 用于高速无线光通信的光正交频分复用

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08) Pub Date : 2008-05-05 DOI: 10.1109/WOCN.2008.4542479

Mohamed E. Khedr, Moustafa H. Aly, M. Tamazin

引用次数: 4

A multi-band timing synchronization scheme for ultra-wideband communication 一种用于超宽带通信的多频带定时同步方案

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08) Pub Date : 2008-05-05 DOI: 10.1109/WOCN.2008.4542539

D. Sen, S. Chakrabarti, R.V.R. Kumar

引用次数: 2

Performance study of an optical backbone MAC interconnecting WiMAX base stations over a city/county area 城县地区WiMAX基站的光骨干MAC互连性能研究

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08) Pub Date : 2008-05-05 DOI: 10.1109/WOCN.2008.4542496

G. Dutta, D. Das

{"title":"Performance study of an optical backbone MAC interconnecting WiMAX base stations over a city/county area","authors":"G. Dutta, D. Das","doi":"10.1109/WOCN.2008.4542496","DOIUrl":"https://doi.org/10.1109/WOCN.2008.4542496","url":null,"abstract":"WiMAX standard's medium access control (MAC) protocol supports QoS for real time traffic. Single WiMAX can cover 10 Kms with broad band support of around 22 Mbps in downlink and 6 Mbps in uplink [7]. Multiple WiMAX base stations (BSs) are needed to cover a thickly populated city or county with large diameter (i.e., above 20 kms, which is very common). To maintain QoS for inter WiMAX BSs traffic, it is important to have a supportive MAC protocol on interconnecting network (referred as backbone). In this paper we propose optical backbone connectivity operating at 2.5 Gbps for inter networking several WiMAX BSs located in various location of large cities/county. We propose a novel hybrid- MAC protocol that caters to the QoS needs for real time service with negligible jitter and provides minimum delay for non-real time data traffic of WiMAX. The backbone delay for best effort traffic has been analyzed under various circumstances of real time as well as non-real time traffic. Furthermore, the results reveal that with reasonable load on the backbone there is hardly any impact on packet delay for even Best Effort services.","PeriodicalId":363625,"journal":{"name":"2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123721456","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: 4