搜索结果: 1-15 共查到“工学 QPSK”相关记录107条 . 查询时间(0.051 秒)
南京师范大学物理科学与技术学院通信原理实验课件实验十二 QPSK调制与解调实验。
Single-carrier 400G interface and 10-channel WDM transmission over 4,800 km using all-ETDM 107-Gbaud PDM-QPSK
Single-carrier 400G interface 10-channel WDM transmission over 4,800 km all-ETDM 107-Gbaud PDM-QPSK
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2014/11/6
We transmit all-electronically multiplexed 107-Gbaud polarization-multiplexed quadrature-phase-shift-keying over 4,800-km using coherent detection based on a real-time oscilloscope with 63-GHz electro...
基于非线性滤波估计的北斗B1 QPSK 信号跟踪方法
北斗信号 载波跟踪 非线性卡尔曼滤波 状态反馈控制
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2015/5/19
复杂环境下的多普勒频移变化及信号功率衰减均会对载波准确跟踪造成影响。在研究北斗卫星B1频点信号结构的基础上，建立以环路中相关积分值为观测量的非线性EKF模型和UKF模型，并提出利用滤波估计状态量进行状态反馈控制的方法，从而解决了载波跟踪环路在高动态及弱信号环境中难以高性能工作的问题。实验结果表明，状态反馈控制的EKF模型和UKF滤波模型能准确地跟踪弱信号及高动态下的信号变化，从而有效控制跟踪误差，...
高性能无数据辅助QPSK频偏估计新算法
QPSK 无数据辅助 频偏估计 去调制
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2013/11/2
针对无数据辅助的正交相移编码(QPSK)载波频偏估计，提出了一种去除调制信息的新方法，基于该方法又提出新的QPSK频偏估计算法，并结合离散傅里叶变换粗频偏估计方法对大频偏进行估计．与插值离散傅里叶变换频偏估计算法相比，新算法提高了对频偏变化的适应能力，使之在频偏缓变的情况下依然可以准确估计频偏．仿真以及FPGA实现结果表明，新算法在低信噪比下仍能接近克拉美罗界．
基于恒模特性的QPSK-DSSS信号扩频序列估计
QPSK-DSSS信号 扩频序列 信号子空间 恒模特性 酉阵模糊
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2013/9/14
针对非合作低信噪比条件下的QPSK-DSSS信号,提出一种基于恒模特性的扩频序列估计算法。该算法首先将单用户QPSK-DSSS信号等效为两用户的BPSK-DSSS信号,其次通过对信号协方差矩阵进行特征分解,估计出由同相与正交两路扩频序列张成的二维信号子空间,最后利用扩频序列的恒模特性消除特征分解带来的酉阵模糊问题,实现扩频序列的精确估计。本文提出算法实现简单,相对目前现有传统算法具有较低的计算复杂...
QPSK调制下最大平均互信息量化在LDPC译码中的应用
四进制相移键控调制 最大平均互信息量化 最小和算法 整数运算
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2013/5/21
对低密度奇偶校验(low-density parity-check, LDPC)码在四进制相移键控(quaternary phase shift keying, QPSK)调制下的译码算法进行了深入研究，分析和推导了最大平均互信息量化的具体方法。在QPSK调制下，通过此方法量化初始消息，最终使每次迭代的变量消息和校验消息都是整数，实现了基于整数运算的最小和译码算法。仿真结果表明，其性能与基于高精度...
A W-Band Photonic Transmitter-Mixer Based on High-Power Near-Ballistic Uni-Traveling-Carrier Photodiodes for BPSK and QPSK Data Transmission Under Bias Modulation
Photonic QPSK Data Abstract
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2011/11/17
THE tremendous increase in the required volume of wireless data-transmission has stimulated attention on ways to use the millimeter-wave (MMW) bands above 60 GHz ( -band) or above 100 GHz ( -band) as ...
对低密度奇偶校验(low-density parity-check, LDPC)码在四进制相移键控(quaternary phase shift keying, QPSK)调制下的译码算法进行了深入研究，分析和推导了最大平均互信息量化的具体方法。在QPSK调制下，通过此方法量化初始消息，最终使每次迭代的变量消息和校验消息都是整数，实现了基于整数运算的最小和译码算法。仿真结果表明，其性能与基于高精度...
40 Gbit/s 相干偏振复用QPSK传输中基于Manakov方程的非线性补偿
正交相移键控 非线性补偿 Manakov方程
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2011/8/11
在40 Gbit/s相干偏振复用正交相移键控（QPSK）传输系统中,为了补偿由于光纤中非线性效应引起的传输信号损伤,采用了基于Manakov方程的反向传播非线性补偿算法.传统的基于标量非线性薛定谔方程（NLSE）的反向传播算法忽略了偏振模色散（PMD）的作用,因此在偏振复用系统中不能补偿由于PMD引起的信号损伤|而基于Manakov方程的数字信号处理方法能够对PMD与克尔非线性效应的耦合作用进行补...
MLSE-Based Nonlinearity Mitigation for WDM 112 Gbit/s PDM-QPSK Transmissions with Digital Coherent Receiver
Coherent communications Fiber optics communications
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2015/5/26
We investigate the performance of linear equalization combined with MLSE in long-haul transmission. In the nonlinear regime with high launch powers Q-factor improvement up to 1.4 dB is demonstrated wi...
Polarization Multiplexed (D)QPSK InP Receiver Photonic Integrated Circuits
Photonic integrated circuits Fiber optics communications Optoelectronics
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2015/5/26
In this paper we review recent developments in the area of receiver photonic integrated circuits for the implementation of polarization multiplexed (differentially coded), quadrature phase shift keyin...
Interplay between PMD and Nonlinearity in 112 Gb/s DP-QPSK Transmission with Co-propagating 10.7 Gb/s NRZ Channels
Fiber optics communications Coherent communications
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2015/5/26
We experimentally demonstrate interplay between PMD and nonlinearity in 112 Gb/s DP-QPSK signal transmission with 10.7 Gb/s NRZ neighbors can have both positive and negative impact depending on channe...
Fast Parallelized Simulation of 112 Gb/s CP-QPSK Transmission Systems using Stratified Monte-Carlo Sampling
Fiber optics communications Coherent communications
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2015/5/26
A novel parallelized implementation of the split-step Fourier method on graphics processing units was developed. The combination of Monte-Carlo simulations with single and double precision yields a sp...
Impact of the Channel Count on the Nonlinear Tolerance in Coherently-detected POLMUX-QPSK modulation
Coherent communications Fiber optics communications
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2015/5/26
GPU-based transmission simulations with different channel counts (1~81) are used to determine the minimum required channel number for correctly simulating fiber nonlinearities that impact 40G/100G CP-...
Generation of 5-Gbps QPSK Signal using Directly Modulated RSOA for 100-km Coherent WDM PON
Fiber optics links subsystems Coherent communications
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2015/5/22
We generate the QPSK signal by utilizing the chirp characteristics of the directly modulated RSOA for the high-speed coherent WDM PON. In addition, we demonstrate the error-free transmission of the 5-...