Description: On the Energy Detection of Unknown Signals Over Fading ChannelsAbstract—This letter addresses the problem of energy detection of an unknown signal over a multipath channel. It starts with the no-diversity case, and presents some alternative closed-form expressions for the probability of detection to those recently reported in the literature. Detection capability is boosted by implementing both square-law combining and square-law selection diversity schemes. Index Terms—Diversity schemes, energy detection, fading channels, low-power applications, square-law detector, unknown signal detection. Platform: |
Size: 174453 |
Author:chenpeng3361 |
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Description: 多径信道仿真
有三条固定路径的AWGN多径信道的QPSK系统进行BER性能方针，并与在理想的AWGN信道中同样系统的BER进行比较，为简化模型，作如下假设：
1，信道中有三条路径，包括一条没有衰落的LOS路径和两条具有瑞利衰落的路径。与各路径相应的接收功率以及路径间的延迟差是仿真的参数
2，信道的锐利衰落仅影响发送信号的幅度，不影响瞬时相位。
3，在符号间隔内各多径分量的衰减幅度是常数，并与相邻间隔无关。-Multipath channel simulation There are three fixed path multipath AWGN channel BER performance of QPSK systems approach, and in an ideal AWGN channel BER the same system for comparison, in order to simplify the model, make the following assumptions: 1, There are three channels path, including a no decline LOS path and the two have a Rayleigh fading path. Corresponding with the path to receive power as well as the path delay difference between the simulation parameters of 2, channel sharp decline affects only the magnitude of the transmitted signal, does not affect the instantaneous phase. 3, in the symbol intervals multipath component of the decay rate is constant, and has nothing to do with the next interval. Platform: |
Size: 5120 |
Author:TT |
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Description: OnPerformanceLimitsofDFTSpreadOFDMSystems
DFT Spread OFDM has been proposed recently to
reduce the Peak to Average Power Ratio (PAPR) of conventional
OFDM transmission. Besides PAPR reduction, an important
implication of DFT Spreading is that the independent parallel
sub-channels between the sub-carriers cease to exist. This in
turn leads to difference in its performance limits as compared to
the conventional OFDM system. This paper analyzes the error
probabilities of DFT Spread OFDM systems, and derives their
analytical closed form expressions for the AWGN, fading AWGN,
multipath and fading multipath channel scenarios. Simulation
results presented in last section confirm the validity of the derived
analytical expressions. Platform: |
Size: 2151424 |
Author:ashokec |
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Description: 对3条固定路径的AWGN多径信道中的QPSK系统进行BER性能仿真（不同p和delay 的取值来分别定义莱斯（瑞利）平坦衰落信道、莱斯（瑞利）频率选择性衰落信道).-For three fixed-path multipath AWGN channel of the QPSK system BER performance simulation (different values for p and the delay are defined Rice (Rayleigh) flat fading channel, Rice (Rayleigh) frequency-selective fading channels ). Platform: |
Size: 8192 |
Author:minmin |
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Description: 要求对有3条固定路径的AWGN多径信道中的QPSK系统进行BER性能仿真，并与在理想的AWGN信道中同样系统的BER性能进行比较。熟悉瑞利平坦衰落、莱斯平坦衰落与频率选择性衰落的特点，比较这些衰落信道的误码率。-Required to have three fixed-path AWGN multipath channels of QPSK system BER performance simulation, and in an ideal AWGN channel with the same system BER performance comparison. Familiar with the Rayleigh flat fading, Rice flat fading and frequency selective fading characteristics, compare the bit error rate fading channel. Platform: |
Size: 1024 |
Author:沈岗 |
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Description: Orthogonal Frequency Division Multiplexing (OFDM) is a spectrally efficient multicarrier modulation technique for high speed data transmission over multipath fading channels. High Peak-to-Average Power Ratio (PAPR), which leads to power inefficiency in the RF portion of the transmitter, is a major drawback of OFDM. Platform: |
Size: 78848 |
Author:yasora |
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Description: As a multi-carrier modulation scheme, Orthogonal Frequency Division Multiplexing (OFDM)
technique can achieve high data rate in frequency-selective fading channels by splitting a
broadband signal into a number of narrowband signals over a number of subcarriers, where
each subcarrier is more robust to multipath. The wireless communication system with multiple
antennas at both the transmitter and receiver, known as multiple-input multiple-output
(MIMO) system, achieves high capacity by transmitting independent information over different
antennas simultaneously. The combination of OFDM with multiple antennas has been
considered as one of most promising techniques for future wireless communication systems. Platform: |
Size: 2609152 |
Author:ashish |
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Description: This demo shows how to simulate multiple-input multiple-output (MIMO) multipath fading channels based on the IEEE® 802.11n channel models for indoor wireless local area networks (WLAN). -This demo shows how to simulate multiple-input multiple-output (MIMO) multipath fading channels based on the IEEE® 802.11n channel models for indoor wireless local area networks (WLAN). Platform: |
Size: 177152 |
Author:riham |
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Description: Approximate Equation of Bit Error Rate in OFDM Systems over Specular Multipath Fading Channels Platform: |
Size: 387072 |
Author:sayeed |
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Description: Research towards meeting the higher demands for
higher data rates was the main reason for the birth of an
evolution technology towards the 4th generation mobile
communication systems. This evolution to the current 3rd
generation UMTS systems was given the name E-UTRA/UTRAN
Long Term Evolution (LTE) by the 3GPP. This paper analyzes
the requirements for this evolution and evaluates the
performance of the OFDM-LTE system under different
propagation impairments (AWGN and multipath fading
channels involving Pedestrian and Vehicular scenarios) in terms
of bit and symbol error rates (BER and SER) for different
modulation formats. Platform: |
Size: 3643392 |
Author:Dang Dung |
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Description: An Adaptive Block-Based Eigenvector Equalization for Time-Varying Multipath Fading Channels.In this paper we present an adaptive Block-
Based EigenVector Algorithm (BBEVA) for blind equalization
of time-varying multipath fading channels. In addition
we assess the performance of the new algorithm for different
configurations and compare the results with the
least mean squares (LMS) algorithm. The new algorithm is
evaluated in terms of intersymbol interference (ISI) suppression,
mean squared error (MSE) and by examining the
signal constellation at the output of the equalizer. Platform: |
Size: 261120 |
Author:abd091 |
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Description: 瑞利衰落信道（Rayleigh fading channel）是一种无线电信号传播环境的统计模型。这种模型假设信号通过无线信道之后，其信号幅度是随机的，表现为“衰落”特性，并且多径衰落的信号包络服从瑞利分布。由此，这种多径衰落也称为瑞利衰落。 这一信道模型能够描述由电离层和对流层反射的短波信道，以及建筑物密集的城市环境。瑞利衰落只适用于从发射机到接收机不存在直射信号的情况，否则应使用莱斯衰落信道作为信道模型。-Rayleigh fading channel, Rayleigh fading channel) is a statistical model of radio signal propagation environment. This model assumes that the signal through a wireless channel, its signal amplitude is random, show the "decline" features, and multipath fading signal envelope obeys Rayleigh distribution. As a result, the multipath fading is also called Rayleigh fading. The channel model can be described by the ionosphere and troposphere reflect shortwave channel, as well as a built-up urban environment. Rayleigh fading is only applicable to direct signal from the transmitter to the receiver does not exist, or rice fading channels as channel models should be used.
Platform: |
Size: 16384 |
Author:李晓林 |
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Description: 此程序描述OFDM系统中多径衰落信道的仿真和实现，包含信道转移矩阵的计算和变换等-This procedure describes the OFDM system simulation and implementation of multipath fading channels, including the calculation and conversion channel transfer matrix, etc. Platform: |
Size: 2048 |
Author:putaozi |
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Description: this code give a matlab model for simulation the time varing channels with rayligh fading and soppler types spectrum for ofdm signals. Platform: |
Size: 6144 |
Author:sadegh |
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Description: this code give a matlab model for simulation the time varing channels with rayligh fading and soppler types spectrum for ofdm signals. Platform: |
Size: 7168 |
Author:ivrkeata |
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Description: Timing Synchronization for 802.11a WLANs under Multipath Channels
In the Wireless Local Area Network
(WLAN) standard adopted by the IEEE 802.11a
standardization group, each data packet starts with a
preamble, which consists of ten short training symbols
followed by two long training symbols. In this paper,
we present an efficient and straightforward coarse
timing synchronization scheme based on the short
training symbols. Simulation results illustrate that the
performance of the proposed scheme is comparable
and even superior to that of the conventional timing
synchronization method under multipath fading
channels. We further show that the combination of
the proposed auto-correlation coarse timing
synchronization scheme and a frequency domain path
delay moving average method leads to a desirable
result of symbol timing estimation. Platform: |
Size: 218112 |
Author:Mohamed |
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Description: There is a simulation of Orthogonal Frequency Division Multiplexing (OFDM) in by multipath fading channels.
-There is a simulation of Orthogonal Frequency Division Multiplexing (OFDM) in by multipath fading channels. Platform: |
Size: 65536 |
Author:jiang nan |
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Description: As we step forward into the new millennium with wireless technologies leading
the way in which we communicate, it becomes increasingly clear that the
dominant consideration in the design of systems employing such technologies
will be their ability to perform with adequate margin over a channel perturbed
by a host of impairments not the least of which is multipath fading. This is not
to imply that multipath fading channels are something new to be reckoned with,
indeed they have plagued many a system designer for well over 40 years, but
rather, to serve as a motivation for their ever-increasing significance in the years
to come. At the same time, we do not in any way wish to diminish the importance
of the fading channel scenarios that occurred well prior to the wireless revolution,
since indeed many of them still exist and will continue to exist in the future. In
fact, it is safe to say that whatever means are developed for dealing with the
more sophisticated wireless application will no doubt also be useful for dealing
with the less complicated fading environments of the past. Platform: |
Size: 3619002 |
Author:jivisadirov@gmail.com |
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Search - multipath fading channels