Description: 本文首先概述了OFDM 的原理、特征和关键技术，介绍了系统需要的几种同步。然后就同步误差对系统性能的影响进行了简单的分析，表明定时偏差和采样频率偏差将会引入码间干扰，载波频率偏差导致载波间干扰的发生。因此，在OFDM系统接收机中定时的确定、载波频率偏差和采样频率偏差的纠正是信号恢复的关键。之后对OFDM系统同步的几种实现方法进行了介绍，分析了各同步方法的性能。-The paper first outlines the principles of OFDM, features and key technologies, the system needs to introduce several synchronization. Synchronization error and then the impact on system performance for a simple analysis, show that the timing deviation and the sampling frequency deviation will introduce inter-symbol interference, the carrier frequency deviation led to the occurrence of ICI. Therefore, in OFDM system receiver to determine the timing, carrier frequency offset and sampling frequency offset correction signal to restore the key. After the OFDM system to achieve synchronization of several methods of introduction, an analysis of the performance of the synchronization method. Platform: |
Size: 268288 |
Author:dajinyu |
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Description: 本程序仿真一个从卫星到区域数据中心的下行链路（由一组6个载波构成），评估热噪声，交调（IM）失真、由滤波器造成的码间干扰（ISI）以及邻频干扰对下行链路性能的影响。-This procedure simulation of a regional data from the satellite downlink center (by a group of six carrier constituted) to assess the thermal noise, Intermodulation (IM) distortion, caused by the filter inter-symbol interference (ISI) and interference邻频on the downlink performance. Platform: |
Size: 88064 |
Author:三明 |
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Description: Phase noise resulting in Common Phase Error
(CPE) and Inter-Carrier Interference (ICI) is a critical challenge
to the implementation of OFDM systems. Modeling phase noise
as a stationary Gaussian random process with the specified
power spectrum density, different from conventional approaches
which mostly relay on pilots to provide CPE estimation, we
explore the statistical characteristics of the sufficient statistics
then propose a pilot-aided decision-directed approach according
to maximum-likelihood criterion. Numerical results demonstrate
that the proposed algorithm enjoys 2dB gain at moderate SNR
and is quite robust against possible model mismatch Platform: |
Size: 148480 |
Author:xiaobo |
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Description: Phase noise resulting in Common Phase Error
(CPE) and Inter-Carrier Interference (ICI) is a critical challenge
to the implementation of OFDM systems. Modeling phase noise
as a stationary Gaussian random process with the specified
power spectrum density, different from conventional approaches
which mostly relay on pilots to provide CPE estimation, we
explore the statistical characteristics of the sufficient statistics
then propose a pilot-aided decision-directed approach according
to maximum-likelihood criterion. Numerical results demonstrate
that the proposed algorithm enjoys 2dB gain at Platform: |
Size: 84992 |
Author:xiaobo |
Hits:
Description: Phase noise resulting in Common Phase Error
(CPE) and Inter-Carrier Interference (ICI) is a critical challenge
to the implementation of OFDM systems. Modeling phase noise
as a stationary Gaussian random process with the specified
power spectrum density, different from conventional approaches
which mostly relay on pilots to provide CPE estimation, we
explore the statistical characteristics of the sufficient statistics
then propose a pilot-aided decision-directed approach according
to maximum-likelihood criterion. Numerical results demonstrate
that the proposed algorithm enjoys 2dB gain at moderate SNR
and is quite robust against possible model mismatch Platform: |
Size: 6144 |
Author:xiaobo |
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Description:
应用OFDM可以有效地对抗多径时延扩展。循环前缀不仅可以消除符号间干扰（ISI），还能消除子载波间干扰（ICI).本项目完整地仿真了OFDM系统。-Application of OFDM can effectively combat multipath delay spread. Cyclic prefix can not only eliminate inter-symbol interference (ISI), can eliminate Inter-carrier interference (ICI). This project a complete simulation of the OFDM system. Platform: |
Size: 41984 |
Author:吏继斌 |
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Description: 分析了相位噪声对正交频分复用(OFDM)系统的影响,发现相位噪声不仅产生
通用相角错误(CPE),而且还会产生载波间干扰(ICI),这都使OFDM系统的性能急剧恶
化,因此必须对CPE和ICI进行校正.文中给出了基于MSE准则的CPE校正方法,考虑到
ICI干扰主要来源于相邻信道,进而提出了基于LMS法则的自适应相邻信道干扰消除方
法.整个算法简单高效.仿真结果表明,所提出的算法大大改善了OFDM系统的性能-Analysis of phase noise on the orthogonal frequency division multiplexing (OFDM) system, the impact of phase noise was found not only from the general phase angle error (CPE), but also generate inter-carrier interference (ICI), which are so dramatically the performance of OFDM system worse, it is necessary CPE and ICI correction. This paper gives guidelines for CPE-based MSE correction methods, taking into account ICI mainly come from the adjacent channel interference, then presents a rule-based LMS adaptive adjacent channel interference cancellation method. the algorithm is simple and efficient. The simulation results show that the proposed algorithm greatly improved the performance of OFDM systems Platform: |
Size: 44032 |
Author:sunkai |
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Description: INTER-CARRIER INTERFERENCE CANCELLATION FOR OFDM SYSTEMS:
Orthogonal Frequency Division Multiplexing (OFDM) is an emerging multi-carrier modulation scheme, which has been adopted for several wireless standards such as IEEE 802.11a and HiperLAN2. A well-known problem of OFDM is its sensitivity to frequency offset between the transmitted and received carrier frequencies. This frequency offset introduces inter-carrier interference (ICI) in the OFDM symbol. This project investigates three methods for combating the effects of ICI: ICI self-cancellation (SC), maximum likelihood (ML) estimation, and extended Kalman filter (EKF) method. These three methods are compared in terms of bit error rate performance, bandwidth efficiency, and computational complexity. Through simulations, it is shown that the three techniques are effective in mitigating the effects of ICI. For high values of the frequency offset and for higher order modulation schemes, the ML and EKF methods perform better than the SC method. Platform: |
Size: 390144 |
Author:redami |
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Description: 传统均衡器无法有效地同时对抗这两种信道衰落，而Turbo均衡技术作为一种联合信道均衡和信道译码的方法，能有效地对抗符号间干扰（ISI），提供迭代增益，提高接收机的整体性能。因此，本文根据下一代无线通信系统的设计要求，分别对单载波和OFDM系统的Turbo均衡算法进行了研究。
-Conventional equalizer can not effectively fight both at the same time fading, while the Turbo equalization as a joint channel equalization and channel decoding method is robust against inter-symbol interference (ISI), provides iteration gain, improved receiver overall performance. Therefore, this next-generation wireless communication system according to the design requirements, namely, the single carrier and OFDM systems Turbo equalization algorithm is studied. Platform: |
Size: 703488 |
Author:w |
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Description: The loss of sub channel orthogonality leads to inter-carrier interference (ICI). Using many algorithms for
channel estimation, we will show Platform: |
Size: 58368 |
Author:osama |
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Search - Inter carrier interference