Description: 国外OFDM经典书籍，介绍正交频分复用（OFDM）技术的原理及其在无线通信领域内的应用，包含无线通信系统的发展历程以及无线衰落信道的基本特性，OFDM技术的基本原理与特性，OFDM技术内峰值平均功率比，同步和信道估计等问题-OFDM abroad classic books, Introduction Orthogonal Frequency Division Multiplexing (OFDM) technique and its application in the field of wireless communications applications, including wireless communication systems, as well as the development process of the wireless fading channel basic characteristics, OFDM technology, the basic principles and characteristics of , OFDM technology within the peak-average power ratio, synchronization and channel estimation issues such as Platform: |
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Author:wan |
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Description: 对无线通信信道中的衰落进行了仿真。考虑到无线通信中，频移及接受台移动速度等因素。
-Wireless communication channel for the decline of the simulation. Taking into account the wireless communications, the frequency shift and acceptance of mobile speed and other factors. Platform: |
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Author:晓慧 |
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Description: This project aim was to build wireless software modem for data communication
between two computers using an acoustic interface in the voice frequency range (20Hz–
20,000Hz). The transmitting antenna is a speaker (frequency response of: 90Hz –
20,000Hz) and the receiving antenna is a microphone (frequency response of: 100Hz –
16,000Hz). The test files used as information files were text files.
This goal was attained both in an incoherent scheme and in a coherent scheme.
Build under Matlab code, our modem uses OFDM (orthogonal frequency division
multiplexing) modulation, synchronization by LMS sequence, channel estimation (no
equalizer) via pilot tones. The symbols are either PSK or ASK for a constellation size of
2 or 4. To optimize the probability of error, these symbols were mapped using Gray
mapping.
Report-This project aim was to build wireless software modem for data communicationbetween two computers using an acoustic interface in the voice frequency range (20Hz-20000Hz). The transmitting antenna is a speaker (frequency response of: 90Hz-20000Hz) and the receiving antenna is a microphone (frequency response of: 100Hz-16000Hz). The test files used as information files were text files.This goal was attained both in an incoherent scheme and in a coherent scheme.Build under Matlab code, our modem uses OFDM ( orthogonal frequency divisionmultiplexing) modulation, synchronization by LMS sequence, channel estimation (noequalizer) via pilot tones. The symbols are either PSK or ASK for a constellation size of2 or 4. To optimize the probability of error, these symbols were mapped using Graymapping.Report Platform: |
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Author: |
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Description: (1) 在某些无线信道中，多普勒频移会引起无线信道输出信号的混叠。请描述产生混叠的各种原因；
(2) 无线信道中的多普勒谱有一种经典谱(classic spectrum)，请解释产生这种谱形状的机理；
(3) 请用Simulink工具编写代码(S-Function方式)，产生一单径瑞利信道，其多普勒谱为经典谱，其中移动速率为120km/h。并请回答：证明自己用计算机产生的经典谱是正确的可能方法。
-(1) in certain wireless channel, the Doppler frequency shift will be caused by wireless channel output signal aliasing. Please describe the resulting aliasing of a variety of reasons (2) wireless channel Doppler spectrum there is a classical spectrum (classic spectrum), please explain such a spectral shape of the mechanism (3) Please use Simulink tools for writing code ( S-Function mode), resulting in a single Path Rayleigh channel, the Doppler spectrum for the classical spectrum, including mobile rate of 120km/h. And please answer: prove that they used computer-generated classical spectrum is correct possible ways. Platform: |
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Author:haohao |
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Description: 把地理区域分成一个个小区，蜂窝系统在该区域内提供无线覆盖。把可用的频谱分成很多信道，每个小区分配一组信道。使用频分双工（FDD）。在小区间进行频率利用，N个小区构成一个簇，簇间进行频率复用。定义了传播特性（信道参数）以及同频小区的位置。信道的参数包括：小区半径，路径损耗指数，以分贝为单位的对数正态阴影的标准差，基站发射功率级，移动台发射功率级，每个小区的扇区数，扇区化天线的正反向比，要仿真的瞬时位置的组数，同频干扰阈值。-To a geographical area is divided into small areas, cellular systems in the region to provide wireless coverage. The available spectrum is divided into multi-channel, each plot the distribution of a group of channels. The use of frequency division duplex (FDD). In the district between the frequency of use, N plots constitute a cluster, cluster between frequency reuse. The definition of the propagation characteristics (channel parameters), as well as with the frequency of residential location. Channel parameters include: cell radius, path loss index to decibels for units Lognormal shadow of the standard deviation, the base station transmitter power level, mobile station transmitting power level, the number of sectors in each district, sector of the antenna the pros and cons to the ratio, to the transient simulation of the group a few positions, the same frequency interference threshold. Platform: |
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Author:mame |
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Description: 完整的OFDM链路程序并作了较为具体的解析从基本的bpsk,qpsk,qam到实际的ofdm系统，cdma链路，mac层仿真分析.-Orthogonal frequency division multiplexing (OFDM) is becoming the chosen
modulation technique for wireless communications. OFDM can provide large data
rates with sufficient robustness to radio channel impairments. Many research centers
in the world have specialized teams working in the optimization of OFDM for
countless applications. Here, at the Georgia Institute of Technology, one of such
teams is in Dr. M. A. Ingram’s Smart Antenna Research Laboratory (SARL), a part
of the Georgia Center for Advanced Telecommunications Technology (GCATT).
The purpose of this report is to provide Matlab code to simulate the basic processing
involved in the generation and reception of an OFDM signal in a physical
channel and to provide a description of each of the steps involved. For this purpose,
we shall use, as an example, one of the proposed OFDM signals of the Digital
Video Broadcasting (DVB) standard for the European terrestrial digital television
(DTV) service. Platform: |
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Author:田静 |
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Description: Frequency domain characterization of los nonfading indoor wireless LAN channel employing frequency and polarization diversity in the 63.4 to 65.4GHz band Platform: |
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Author:magicz |
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Description: 正交频分复用（OFDM，Orthogonal Frequency Division Multiplexing）是一种多载波数字调制技术，也可以被当作一种复用技术。具有频谱利用率高、抗多径干扰等特点，OFDM系统能够有效地抵抗无线信道带来的影响，例如信道的频率选择性衰落，脉冲噪声和共信道干扰的影响。本文主要介绍了OFDM原理的相关知识。-The Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) is more than one kind of carrier digital modulation technology, may also treat as one kind of multiplying technology. Has the frequency spectrum use factor high, characteristics and so on anti-multi-diameter disturbance, the OFDM system can resist the influence which effectively the wireless channel brings, for example channel s frequency selectivity declines, impulse noise/pulse noise/pulsive noise and altogether channel disturbance influence. This article mainly introduced the OFDM principle related knowledge. Platform: |
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Author:卡其米奇 |
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Description: This paper deals with the capacity behavior of wireless Orthogonal Frequency Division Multiplexing
(OFDM)-based spatial multiplexing system when considering realistic channel delay profiles.
In both the SISO and the MIMO contexts, we compare the deterministic, ergodic and outage
capacities for the channel with realistic profile to the one with simplified profile Platform: |
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Author:Safa |
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Description: 2. 关于无线信道的多普勒谱，请回答以下问题：
(1) 在某些无线信道中，多普勒频移会引起无线信道输出信号的混叠。请描述产生混叠的各种原因；
(2) 无线信道中的多普勒谱有一种经典谱(classic spectrum)，请解释产生这种谱形状的机理；
(3) 请用Simulink工具编写代码(S-Function方式)，产生一单径瑞利信道，其多普勒谱为经典谱，其中移动速率为120km/h。并请回答：证明自己用计算机产生的经典谱是正确的可能方法。
-On the wireless channel of the Doppler spectrum, please answer the following questions: (1) In some radio channels, the Doppler frequency shift will cause the output signal of the wireless channel aliasing. Please describe the aliasing produced a variety of reasons (2) wireless channel in the Doppler spectrum has a classical spectrum (classic spectrum), please explain the mechanism of produce such spectral shape (3), please use the Simulink tool to write code ( S-Function mode), resulting in a single-path Rayleigh channel, the Doppler spectrum for the classical spectrum, including mobile rate of 120km/h. And requested the answer: that they used computer-generated classical spectrum is the right possible way. Platform: |
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Author:Helen |
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Description: 本书不仅回顾了通信信号处理的经典研究领域，如自适应均衡、信道建模和识别、多用户检测和阵列处理，而且分析研究了一些新领域，如自适应编码调制、多输入多输出（MIMO）系统、分集合并和时频分析。此外，本书还探讨了神经网络、蒙特卡洛马尔可夫链和混沌等新兴技术，并对未来移动通信具有发展前途的方法进行了很好的概括性阐述。-The book investigates classical SP areas such as adaptive equalization, channel modeling and identification,
multi-user detection, and array processing. It also investigates newer areas such as adaptive coded
modulation, multiple-input multiple-output (MIMO) systems, diversity combining, and time-frequency
analysis. It explores emerging techniques such as neural networks, Monte Carlo Markov Chain (MCMC)
methods, and Chaos. It offers an excellent tutorial survey of promising approaches for future mobile
communications such as cross-layer design in multi-access networks and adaptive wireless networks. Platform: |
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Author:YuJD |
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Description: Matlab code to simulation the wireless channel type.This is the most common case called Rayleigh channel.And in the frequency selective channel. Platform: |
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Author:allen |
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Description: Clear Channel Assessment Using TI MSP430 and CC2500 Radio-This application report describes a 2.4-GHz anti-jamming frequency-hopping system consisting of a designated Transmitter and Receiver, each with distinct functions to avoid RF-channel interference. The Transmitter board emulates the control device (e.g., remote control) by sending commands to be processed on the Receiver side (e.g., TV, stereo, set top box, or gaming console). Since many popular consumer devices use the 2.4-GHz RF spectrum (e.g., cordless phones, wireless routers, microwaves, and PC/Bluetooth® accessories), these systems need to implement a proprietary frequency-hopping scheme in the event that the channel being used by the Transmitter/Receiver pair is already being used by other wireless systems in the vicinity. The specific radio device used for this demo is the TI CC2500 (2.4 GHz) RF transceiver module. The TI portfolio also includes the CC1100 RF transceiver (315/433/868/915-MHz ISM/SRD bands), which shares a common set of configuration registers as those used Platform: |
Size: 27648 |
Author:顏嘉宏 |
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Description: 無線通訊中的環境大多為頻率平坦衰弱通道或是頻率選擇性衰弱通道.瑞利分佈為大多延研究的模型,當有多信道輸入
時,其包跡的選擇可以用來測試通道~-Wireless communication frequency in the environment, mostly flat or frequency selective channel debilitating weakness channel. Rayleigh distribution model for most of the extension study, when there are multi-channel input, its envelope can be used to test the choice of channels ~ Platform: |
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Author:Dephiroth |
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Description: An 8-QAM communications channel simulation in Simulink, constructed from a 16-QAM model and using an I,Q correlation receiver.
QAM (quadrature amplitude modulation) is a method of combining two amplitude-modulated (AM) signals into a single channel, thereby doubling the effective bandwidth. QAM is used with pulse amplitude modulation (PAM) in digital systems, especially in wireless applications. In a QAM signal, there are two carriers, each having the same frequency but differing in phase by 90 degrees (one quarter of a cycle, from which the term quadrature arises). One signal is called the ‘I’ signal, and the other is called the ‘Q’ signal. Mathematically, one of the signals can be represented by a sine wave, and the other by a cosine wave. The two modulated carriers are combined at the source for transmission. At the destination, the carriers are separated, the data is extracted from each, and then the data is combined into the original modulating information. -An 8-QAM communications channel simulation in Simulink, constructed from a 16-QAM model and using an I,Q correlation receiver.
QAM (quadrature amplitude modulation) is a method of combining two amplitude-modulated (AM) signals into a single channel, thereby doubling the effective bandwidth. QAM is used with pulse amplitude modulation (PAM) in digital systems, especially in wireless applications. In a QAM signal, there are two carriers, each having the same frequency but differing in phase by 90 degrees (one quarter of a cycle, from which the term quadrature arises). One signal is called the ‘I’ signal, and the other is called the ‘Q’ signal. Mathematically, one of the signals can be represented by a sine wave, and the other by a cosine wave. The two modulated carriers are combined at the source for transmission. At the destination, the carriers are separated, the data is extracted from each, and then the data is combined into the original modulating information. Platform: |
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Author:Griffin Wright |
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Description: *芯片组合为PIC16F690-I/SS + CC1100 (434Mhz)，
*专为目前传统RS485电表设计,可不修改表的软件方式直接将RS485表升级成无
线且具有路由的表
*结合目前高效稳定的无线传输芯片TI CC1100.
*拥有接近于透明串口传输(内置最大缓冲区32 bytes).
*支持一对一,一对多传输
*软件在线目的地址切换
*软件在线信道频率切换
*支持信道侦听功能,降低数据冲撞机会.
*支持数据确认功能,提升数据传送的稳定度.
*支持四个独立输入/出点 (TTL-Level)
*超小尺寸 : 30.00mmX23.5mm(不包括天线)
*低成本天线 ,采用弹簧天线
*输出频率 : 433.92Mhz (标准品)
*输出功率 : +10dBm
*接收感度 : -108dBm-* Chip combination PIC16F690-I/SS+ CC1100 (434Mhz),
* RS485 meter for the current traditional design of the table from time to modify the way the software upgrade directly to the table without RS485
Line and has a routing table
* Combined with the current stable and efficient wireless transmission chip TI CC1100.
* Has a close and transparent serial transmission (built-in maximum buffer 32 bytes).
* Support for one to one, one to many transmission
* Destination Address switch software online
* Software online channel frequency switching
* Support the channel listener function, reduce the chance of data collision.
* Support data confirm but also to enhance data transmission reliability.
* Support 4 independent input/output (TTL-Level)
* Ultra small size: 30.00mmX23.5mm (not including antenna)
* Low-cost antennas, antenna with spring
* Output frequency: 433.92Mhz (standard)
* Output power:+10 dBm
* Receive sensitivity:-108dBm Platform: |
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Author:Henry |
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Description: 正交频分复用技术是近年来发展起来的新技术,在高速无线数据传输领域有很大的应用前景。文章在分析和总结相关文献的基础上,介绍了正交频分复用(OFDM)技术的发展历史,讨论了正交频分复用技术的基本原理和实现方法。通过分析表明,在高速无线通信中OFDM对于消除符号间干扰(ISI),降低系统的复杂度等方面具有很大优势。正交频分复用(OFDM)是一种多载波宽带数字调制技术,它能有效地克服传输中的多径干扰和消除码间串扰,适合于高速率的地面信道视频传输。本文就OFDM技术进行了较为详尽的分析,并对OFDM的传输特性进行了基于FFT算法实现的MATLAB软件模拟及模拟结果分析。 -OFDM is a new technology developed in recent years, high-speed wireless data transmission in the field of great applications. This paper analyzes and summarizes the basis of relevant literature, describes orthogonal frequency division multiplexing (OFDM) technology, history, orthogonal frequency division multiplexing discussed the basic principles and implementation methods. The analysis shows that in the high-speed wireless communication in OFDM symbol for the elimination of interference (ISI), and so reduce the complexity of the system has great advantages. Orthogonal frequency division multiplexing (OFDM) is a multi-carrier wideband digital modulation techniques, can effectively overcome the transmission of multi-path interference and the elimination of intersymbol interference, the ground for high-speed video transmission channel. In this paper, OFDM technology, a more detailed analysis, and transmission characteristics of OFDM FFT algorithm based on the MATLAB software simulation Platform: |
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Author:罗萍 |
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Description: 在3.49-3.51GHZ频段内的典型中国城市环境下，地面信号衰落仍服从经典的指数对数分布。在中度误差（σx =10.291）下，路损指数在3.1-3.7之间。半径2公里的小区内，RMS时延在3-4微秒之间；典型的办公室环境中，存在直达径时RMS时延小于0.1微秒。在城市环境中，多径现象很明显，主要由高层建筑物引起，并以簇的方式存在。在城市中低速移动条件下（接收机移动速度小于100 Km/h）某一强径的生存时间通常超过10分钟，但相对到达时间会发生滑动。单一小区内的传播环境具有一定相关性，如果存在直达径，相关性会上升到0.4-0.5。此外，室外室内的测量结果都可以证明Jake模型关于入射角分布假设的合理性。当天线间距在1个载波波长增大到10个载波波长时，天线相关性在0.05-0.4之间。
SIMO信道探测系统能够揭示B3G信道的很多特征，但不能够全面、充分的分析和评估B3G信道。在后续工作中，我们将进一步改进这个测试系统，对B3G系统作更深入的研究。
参考-Aided by a 1-Tx and 2-Rx system working in 3.5GHz frequency and 20MHz bandwidth, JSI-MTLab studied the classic B3G urban wireless propagation environment of China and the classic indoor channel propagation environment through a recent indoor and outdoor wireless propagation measurement. A new path loss exponent is proposed in such band while the general outdoor model of path loss is verified. Also, the statistic results of RMS excess delay, max excess delay and mean excess delay in both indoor and outdoor scenarios are given. The lag-time domain and time-frequency domain channel responses are analyzed. At the end, the results of correlation of different propagation environment in the singular cell and antenna correlation are given as well as the phenomenon being analyzed and explained. Platform: |
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Author:xuchen |
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Description: 在某些无线信道中，多普勒频移会引起无线信道输出信号的混叠的原因；无线信道中的多普勒谱有一种经典谱(classic spectrum)产生的机理；-In some wireless channel, the reason of Doppler frequency shift causing aliasing Doppler spectrum in the wireless channel, the mechanism of Generating a classical spectrum (classic spectrum) Platform: |
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Author:梁赛赛 |
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Description: 学习信道建模的经典教材！尤其是对无线信道建模空时频特性进行仿真的一部重要书籍。-A classic learning textbook about wireless channel modeling!Especially it s an important book for the time-space and frequency characteristics of wireless channel modeling simulation . Platform: |
Size: 8982528 |
Author:biyuming |
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Search - wireless channel frequency