Mainly due to its implementation simplicity, the non-coherent Ultra-Wide Band (UWB) receiver is attractive for lower data rate applications, which gains much attention again in recent years. In this paper, a General L...Mainly due to its implementation simplicity, the non-coherent Ultra-Wide Band (UWB) receiver is attractive for lower data rate applications, which gains much attention again in recent years. In this paper, a General Likelihood Ratio Test (GLRT) based non-coherent receiver on UWB Pulse-Position-Modulation (PPM) signal in multipath channels is derived, and a novel structure is proposed as well. Subsequently, the closed-form expressions of asymptotic error-rate performance related to the non-coherent receiver are also derived and verified.展开更多
This paper presents an approach to calculate dispersion penalty for VSR-1 optical links.Based on parameters of a specific VSR-1 link,dispersion penalties are computed for various modal dispersion bandwidths respective...This paper presents an approach to calculate dispersion penalty for VSR-1 optical links.Based on parameters of a specific VSR-1 link,dispersion penalties are computed for various modal dispersion bandwidths respectively.The worst-case eye closure is expressed numerically by using the signal waveform at time 0,and the signal waveform is obtained in frequency domain through FFT algorithm.By this approach,the dispersion penalty is determined by the shape of transfer functions of the various components in the links.To simplify the derivation of multimode fiber link transfer function,a Gaussian form of normalized impulse response is used.This calculation approach can be used to estimate the worst-case dispersion penalty of VSR-1 links in the link budget analysis.展开更多
In this letter,a kind of associated synchronization algorithm which is suitable for HF(High Frequency) broadband OFDM(Orthogonal Frequency Division Multiplexing) system is presented based on describing and constructin...In this letter,a kind of associated synchronization algorithm which is suitable for HF(High Frequency) broadband OFDM(Orthogonal Frequency Division Multiplexing) system is presented based on describing and constructing the GMW(Gorden,Mills and Welch) sequence. The algorithm is based on the Schmidl and Minn's symbol timing principle,the constructed GMW sequence is trans-mitted and disposed,and the synchronization is adjudicated using the correlation of GMW sequence. The simulation result indicates that this algorithm has high performance synchronization ability under the low SNR(Signal to Noise Ratio) at two different kinds of channel models.展开更多
This paper addresses the problem of survivable traffic assignment with failure probability requirement in flexible bandwidth optical networks. We describe a Survivable Traffic Cognition (STC) algorithm with joint fail...This paper addresses the problem of survivable traffic assignment with failure probability requirement in flexible bandwidth optical networks. We describe a Survivable Traffic Cognition (STC) algorithm with joint failure probability. Survivable Traffic Assignment (STA) algorithm and Conventional Traffic Assignment (CTA) algorithm are added to illustrate the effectiveness of our proposed STC. We investigate the effect of joint failure probability on blocking probability, spectral utilization ratio, average joint failure probability, and the average hops. Simulation results show that our proposed STC not only achieves better performance in terms of blocking probability and spectral utilization ratio than CTA and STA, but also does not cause higher average joint failure probability or larger average hops compared with STA. As a result, STC makes the best use of spectral resources and does not cause large average joint failure probability.展开更多
TN247 2002031767通频带宽对脉冲激光波形测量的影响=Influence of the pass band on measurement of laser pulse[刊,中]/田兆硕,王骐,王雨三（哈尔滨工业大学可调谐激光技术国家级重点实验室.黑龙江,哈尔滨（150001））//激光技术.-20...TN247 2002031767通频带宽对脉冲激光波形测量的影响=Influence of the pass band on measurement of laser pulse[刊,中]/田兆硕,王骐,王雨三（哈尔滨工业大学可调谐激光技术国家级重点实验室.黑龙江,哈尔滨（150001））//激光技术.-2001,25（5）.-398-400在理论上分析了电光调Q CO<sub>2</sub>激光脉冲经过不同通频带宽的测量系统时产生的波形失真情况,并且得出了通频带宽对测量波形影响的规律,同时在实验上研究了电光调Q射频激励波导CO<sub>2</sub>展开更多
The integration of cognitive radio and Ultra wideband (UWB) networks has attracted lots of research interests. Cognitive UWB networks not only provide very high data rates but also guarantee the uninterrupted communic...The integration of cognitive radio and Ultra wideband (UWB) networks has attracted lots of research interests. Cognitive UWB networks not only provide very high data rates but also guarantee the uninterrupted communication of primary system operated in the same frequency band. In this work, the problem of the capacity analyses of cognitive UWB networks is investigated. Different from the conventional cognitive spectrum sharing model which can only utilize the idle spectrum hole, the cognitive UWB system can operate adaptively based on spectrum sensing results. Taking into account several factors such as the transmission power constraint of UWB, the interference constraint of the receivers in primary systems, the secondary UWB network capacity problem is modeled as a convex optimization problem over the transmission power. The optimal power allocation strategy and algorithm are derived based on this optimization problem. Two cases (Perfect Spectrum Sensing and Imperfect Spectrum Sensing) are studied in the paper. Numerical simulation results show that the proposed adaptive power allocationscheme improves the ergodic and outage capacity under both transmission power and interference constraints compared with constant transmission power scheme.展开更多
The development of optical transmission was summarized. The multiplexing system was show in detail. The concepts, characteristic, key technology, expand trend and application prospect of frequency division multiplexin...The development of optical transmission was summarized. The multiplexing system was show in detail. The concepts, characteristic, key technology, expand trend and application prospect of frequency division multiplexing, time division multiplexing, code division multiplexing and wave division multiplexing were illustrated.展开更多
A new structure of next generation integrated communication system was proposed, which is composed of space segment based on satellites and terrestrial segment. Moreover, the characteristics of enhanced multiple acces...A new structure of next generation integrated communication system was proposed, which is composed of space segment based on satellites and terrestrial segment. Moreover, the characteristics of enhanced multiple access schemes based on orthogonal frequency division multiplexing (OFDM) technique were analyzed for satellite links. However, OFDM is a doubtful candidate as its higher peak-to-average power ratio (PAPR) that causes the distortion of high power amplifier (HPA). Furthermore, different schemes were evaluated and compared in terms of the HPA nonlinearity and the link level performance in detail. And the pilot-aided channel estimation and equalization techniques were also considered for analyzing the problem. Simulation results show that the bit error rate (BER) and block error rate (BLER) performance of orthogonal frequency division multiple access (OFDMA) outperforms that of single carrier-frequency division multiple access (SC-FDMA) for the satellite links in the proposed structure, though discrete Fourier transform-spread OFDM DFT-S OFDM has low PAPR, especially the BER performance of OFDMA is 3.6 dB larger than that of SC-FDMA at the target BER.展开更多
文摘Mainly due to its implementation simplicity, the non-coherent Ultra-Wide Band (UWB) receiver is attractive for lower data rate applications, which gains much attention again in recent years. In this paper, a General Likelihood Ratio Test (GLRT) based non-coherent receiver on UWB Pulse-Position-Modulation (PPM) signal in multipath channels is derived, and a novel structure is proposed as well. Subsequently, the closed-form expressions of asymptotic error-rate performance related to the non-coherent receiver are also derived and verified.
基金Supported by"863"Hi-Tech Research and Development Program(2005AA311030) and the National Natural Science Foundationof China(Grant No.60502005)
文摘This paper presents an approach to calculate dispersion penalty for VSR-1 optical links.Based on parameters of a specific VSR-1 link,dispersion penalties are computed for various modal dispersion bandwidths respectively.The worst-case eye closure is expressed numerically by using the signal waveform at time 0,and the signal waveform is obtained in frequency domain through FFT algorithm.By this approach,the dispersion penalty is determined by the shape of transfer functions of the various components in the links.To simplify the derivation of multimode fiber link transfer function,a Gaussian form of normalized impulse response is used.This calculation approach can be used to estimate the worst-case dispersion penalty of VSR-1 links in the link budget analysis.
文摘In this letter,a kind of associated synchronization algorithm which is suitable for HF(High Frequency) broadband OFDM(Orthogonal Frequency Division Multiplexing) system is presented based on describing and constructing the GMW(Gorden,Mills and Welch) sequence. The algorithm is based on the Schmidl and Minn's symbol timing principle,the constructed GMW sequence is trans-mitted and disposed,and the synchronization is adjudicated using the correlation of GMW sequence. The simulation result indicates that this algorithm has high performance synchronization ability under the low SNR(Signal to Noise Ratio) at two different kinds of channel models.
基金supported in part by 973 Program under Grants No. 2010CB328204,No. 2012CB315604863 Program under Grant No. 2012AA011301+3 种基金National Natural Science Foundation of China under Grants No. 61271189,No. 61201154, No. 60932004RFDP Project under Grants No. 20090005110013,No. 20120005120019the Fundamental Research Funds for the Central Universitiesthe State Scholarship Fund
文摘This paper addresses the problem of survivable traffic assignment with failure probability requirement in flexible bandwidth optical networks. We describe a Survivable Traffic Cognition (STC) algorithm with joint failure probability. Survivable Traffic Assignment (STA) algorithm and Conventional Traffic Assignment (CTA) algorithm are added to illustrate the effectiveness of our proposed STC. We investigate the effect of joint failure probability on blocking probability, spectral utilization ratio, average joint failure probability, and the average hops. Simulation results show that our proposed STC not only achieves better performance in terms of blocking probability and spectral utilization ratio than CTA and STA, but also does not cause higher average joint failure probability or larger average hops compared with STA. As a result, STC makes the best use of spectral resources and does not cause large average joint failure probability.
文摘TN247 2002031767通频带宽对脉冲激光波形测量的影响=Influence of the pass band on measurement of laser pulse[刊,中]/田兆硕,王骐,王雨三（哈尔滨工业大学可调谐激光技术国家级重点实验室.黑龙江,哈尔滨（150001））//激光技术.-2001,25（5）.-398-400在理论上分析了电光调Q CO<sub>2</sub>激光脉冲经过不同通频带宽的测量系统时产生的波形失真情况,并且得出了通频带宽对测量波形影响的规律,同时在实验上研究了电光调Q射频激励波导CO<sub>2</sub>
基金supported by following projects:NSFC (No. 60432040, 60972079)Beijing Natural Science Foundation (No. 4052021)+1 种基金The Research Fund for the Doctoral Program of Higher Education(No.20060013008, 200700130293)UWB-ITRC Inha University, Korea,and iCHIP Project financed by Italian Ministry of Foreign Affairs,And it is partly supported by Project iCHIP financed by Italian Ministry of Foreign Affairs
文摘The integration of cognitive radio and Ultra wideband (UWB) networks has attracted lots of research interests. Cognitive UWB networks not only provide very high data rates but also guarantee the uninterrupted communication of primary system operated in the same frequency band. In this work, the problem of the capacity analyses of cognitive UWB networks is investigated. Different from the conventional cognitive spectrum sharing model which can only utilize the idle spectrum hole, the cognitive UWB system can operate adaptively based on spectrum sensing results. Taking into account several factors such as the transmission power constraint of UWB, the interference constraint of the receivers in primary systems, the secondary UWB network capacity problem is modeled as a convex optimization problem over the transmission power. The optimal power allocation strategy and algorithm are derived based on this optimization problem. Two cases (Perfect Spectrum Sensing and Imperfect Spectrum Sensing) are studied in the paper. Numerical simulation results show that the proposed adaptive power allocationscheme improves the ergodic and outage capacity under both transmission power and interference constraints compared with constant transmission power scheme.
文摘The development of optical transmission was summarized. The multiplexing system was show in detail. The concepts, characteristic, key technology, expand trend and application prospect of frequency division multiplexing, time division multiplexing, code division multiplexing and wave division multiplexing were illustrated.
基金Project(60532030) supported by the National Natural Science Foundation of China
文摘A new structure of next generation integrated communication system was proposed, which is composed of space segment based on satellites and terrestrial segment. Moreover, the characteristics of enhanced multiple access schemes based on orthogonal frequency division multiplexing (OFDM) technique were analyzed for satellite links. However, OFDM is a doubtful candidate as its higher peak-to-average power ratio (PAPR) that causes the distortion of high power amplifier (HPA). Furthermore, different schemes were evaluated and compared in terms of the HPA nonlinearity and the link level performance in detail. And the pilot-aided channel estimation and equalization techniques were also considered for analyzing the problem. Simulation results show that the bit error rate (BER) and block error rate (BLER) performance of orthogonal frequency division multiple access (OFDMA) outperforms that of single carrier-frequency division multiple access (SC-FDMA) for the satellite links in the proposed structure, though discrete Fourier transform-spread OFDM DFT-S OFDM has low PAPR, especially the BER performance of OFDMA is 3.6 dB larger than that of SC-FDMA at the target BER.
