Questions tagged [fading-channel]

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4
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2answers
604 views

Flat fading criterion of OFDM subcarrier spacing

I have always thought that the OFDM subcarrier spacing $\Delta f$ is chosen such that not too small because Doppler spread can destroy subcarrier orthogonality not too large to avoid Cyclic Prefix (...
0
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0answers
59 views

Help me out in finding the problem in my given MATLAB code of Rectangular Contour Algorithm(RCA)

I am implementing the Rectangular Contour Algorithm (RCA) used for blind channel equalization on 32 Rectangular QAM Signal, polluted with noise and channel effects. It is described in: Khan Q. - ...
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1answer
575 views

Question about path loss exponent estimation from measurment

I have a simple question that confuses me. Assume that we have the following results of a measurement campaign, distance (km) and the corresponding path loss $L_{e}$ (dB). I want to estimate the ...
1
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1answer
131 views

Capacity loss of fast fading regarding AWGN

The theoric capacity of fast fading channel is: $$ C_{\rm fading}=E\left\{\log\left(1+\lvert h \rvert^2\textrm{SNR}\right)\right\}, \quad\text{with $E$ is expectance operator.}$$ At high SNR: $$\...
-1
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1answer
556 views

How to simulate fading channels in MATLAB? [duplicate]

In this page, an example simulating Rician and Rayleigh fading in parallel is given. I knew that Rician fading simulates both line of sight and none light of sight components, so why do we need to ...
-1
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1answer
328 views

i.i.d Raleigh distributed T tap frequency selective channel

A Single-tap 'flat Raleigh fading channel' is implemented as. ...
0
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1answer
101 views

Help in analytical expression of BER for M-QAM [duplicate]

I am new in learning deriving BER expression. I am familiar for the case of BPSK in AWGN but cannot understand how the BER expression in Eq(12) in this paper, An Enhanced Spectral Efficiency Chaos-...
0
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1answer
210 views

Conceptual Question on equalization technique in rayleigh fading channel based on a paper

Question Link http://www.raymaps.com/index.php/theoretical-ber-of-m-qam-in-rayleigh-fading/ gives theoretical expressions for BER in Rayleigh fading channel. Can I use the expression for 64-QAM in ...
0
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1answer
86 views

Multipath fading in wireless channel - parameter needed

I’m trying to implement in Matlab the magnitude of the channel taps of the wireless communication system that is described at page 23 (Section 2.1.4) in the classic book of D. Tse, Fundamentals of ...
1
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1answer
224 views

FWGN model implementation vs explaination (textbook pages attached)

I came across the FWGN model for multipath channel simulation in the book: "MIMO-OFDM Wireless Comuunications with MATLAB" Here is an explanation about Clarke/Gans model: Some code to generate a ...
1
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1answer
1k views

AWGN and Rayleigh fading in slow flat fading channels in MATLAB

I wanted to add Additive White Gaussian Noise (AWGN) and involve effect of slow flat fading on my transmitted signal in Matlab. I created noise with zero mean and variance of one by ...
0
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2answers
7k views

Matlab: Correct method of generating Rayleigh fading channel

A Rayleigh flat fading channel has 1 tap and so there will be no intersymbol interference. if N= 1000; Then, h=(1/sqrt(2))*(randn(N,1)+1i*randn(N,1)); will ...
0
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1answer
521 views

Matlab: Help in applying equalizer and proper calculation of symbol error rate for QAM modulation in Rayleigh channel

I am unable to understand why the Constant Modulus ALgorithm is not functioning properly for QAM modulation in Rayleigh multipath fading. The same code worked for BPSK in AWGN (previous Question ...
6
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1answer
171 views

Practicality of the assumption of i.i.d. for Rayleigh channels

I would like to understand how far the assumption of having i.i.d. is accurate/valid (from the practical point of view) when an OFDM system is working in Rayleigh channels. Is this means the channel ...
3
votes
1answer
1k views

Matlab: Difference between flat fading and Rayleigh multipath fading, terminologies and concept

The information that I put down are from the site http://www.gaussianwaves.com/2011/05/ebn0-vs-ber-for-bpsk-over-rayleigh-channel-and-awgn-channel-2/ . My QUestions are due to some misconception and ...
1
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3answers
195 views

Channel impulse reponse multipaths

I find this image : Does it mean that at 0ns there is one path, 10ns second path, ... and approximately at 130 ns, there is a power path?
0
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0answers
57 views

Parameter selection for log distance path loss model

I am currently referring to the following book MIMO-OFDM Wireless Communications with Matlab in which the log distance path loss model is given by the equation: $P_{LD}(d)[dB] = PL_F(d_0) + 10nlog(d/...
0
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0answers
22 views

Receiver multiple taps

I would like to implement a Rayleigh fading channel for an ASK Modulation. My question is concerning the receiver. How to properly add every tap at the receiver to keep the same length from the ...
3
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1answer
184 views

Channel capacity with additive Gaussian noise with changing variance

As we all know the capacity for a AWGN channel with constant noise variance is just given by $$\frac{1}{2}\log(1+SNR)$$ What if the variance of the noise changes with the type (assuming the variance ...
0
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1answer
577 views

Amplitude distribution of Rician faded complex signal

I have question regarding Rician fading simulation. I am trying to develop Rician fading channel simulator in LabVIEW, but I ran into some problems. I have complex sinusoid as my line-of-signs signal. ...
1
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1answer
164 views

OFDM intra-block multipath interference

We know that OFDM eliminates the inter-block intereference. But there are still multipath interference in a single OFDM block(symbol). How does LTE handle this intra-block interference induced by ...
0
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0answers
18 views

Simulating rain interference

What fading model should I use for simulating rain loss in my network simulations? I am using NS-3 for this and I'm quite lost on how to go about this. My simulation is just simple packet streaming ...