# Questions tagged [fading-channel]

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### Cyclic prefix length in baseband OFDM with ZF equalizer

My question is about baseband OFDM. I try to plot the BER according to the SNR. I noticed that changing cyclic prefix length does not affect the performances. I.e., following the code below, ...
0answers
22 views

### SNR and Correlation

Signal to Noise ratio is essentially the ratio of the signal power to the average noise power. Correlation is the similarity of two signals. Assuming a signal travels through a channel or medium, and ...
1answer
88 views

### Equalizers with low data rate systems

In case of using equalizers with ZigBee systems, what type of fading does the channel show, flat or frequency selective, fast or slow? Is the inter-symbol interference (ISI) problem encountered in ...
1answer
31 views

### Validating Jakes model in Rayleigh Fading channels

I am trying to validate the Jakes model by comparing the autocorrelation function given by $\rho(\Delta t ) = J_{0}(2 \pi f_{d} \Delta t)$, where $f_{d}$ is the maximum Doppler shift, $J_{0}$ is ...
0answers
21 views

### Channel information from power spectra

Linked below is a previous post regarding a multipath channel. Equalisation of FFT spectra I am reusing the images here: The first image is that of the power spectra when there is no multipath and ...
1answer
456 views

### Rayleigh fading with frequency selective fading channel

I Read in one reference that, the Rayleigh distribution is commonly used to describe the statistical time varying nature of the received envelope of a flat fading signal, or the envelope of an ...
0answers
21 views

### Automotive Radar Simulation

I am looking to simulate a radar channel and a waveform to test some ideas from other signal processing domains on automotive radar. However, I have no experience with the typical automotive radar ...
1answer
22 views

### What's the effect of spread spectrum on frequency- selective channel

In brief, we consider the channel as frequency-selective channel if the frequency of the signal is larger than then frequency of channel. So, does using the spreading spectrum change the frequency-...
3answers
52 views

### Explanation a flat fading channel in case MIMO OFDM

I am trying to understand flat fading and frequency selective channels. As I understood, in the case of flat fading channels MIMO channel elements, $h_{i,j}$, are random variables. Which assumption ...
2answers
78 views

### Digital communication BER performance

I've searched for the theoretical equations of bit error rate over Rayleigh flat fading channel basically for binary phase shift key and 16-Quadrature modulation but i didn't find them, could any one ...
1answer
60 views

### Error detection and correction algorithms for Wireless Body Area Networks

I am working on transmitting ECG signals over wireless body area network based on IEEE 802.15.4 standard. To reduce the BER and increase the signal reconstruction quality, I think that I need to ...
0answers
24 views

### Frequency selective channel modeling using rayleighchan object in matlab

I intend to model a frequency selective channel using matlab "comm.RayleighChannel" object. Consider the following command, which sets the parameters of Rayleigh channel : ...
2answers
78 views

### BER of QPSK modulation in Rayleigh fading channel model

i am having trouble deriving a BER analytical expression for QPSK modulation system operating in a Rayleigh Fading channel model. Could anyone direct me to a reference that would help in this matter. ...
1answer
45 views

### channel estimation for cdma

I am looking for a method to make a multi-user channel estimation with CDMA. Here is my question: Is there a way to estimate multi-user channels with their spreading codes? If yes, what is the ...
1answer
418 views

### Flat vs frequency selective fading in MC-CDMA?

I am trying to simulate an MC-CDMA system. I have NXK matrix $S$ which consists of subcarriers ($s_n,_k$ represents subcarrier $n$ of user $k$) and KX1 vector $X$ consists of user symbols. So my ...
3answers
197 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?
1answer
98 views

### Performance evaluation in terms of channel MSE and BER

The first figure on the left (in this paper) provides the channel NMSE performance and the the second figure from left provides detector's BER performance. I am curious, when the channel MSE ...
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 ...
2answers
464 views

### How to compute the channel gain from the path loss model of a wireless channel

I did my research but I did not get a satisfying answer. We have a transmitter and a receiver over a wireless communication channel. The channel's path loss is modeled as $128 + 37 \log_{10} (d)$, ...
0answers
22 views

### Channel models for wireless body area networks

To transmit a signal over wireless body area network, the signal is transmitted over a fading channel with additive white Gaussian noise. The channel model can be obtained from the IEEE standards. My ...
1answer
53 views

### Channel model: LOS Component and Rician K-factor

I am asking about Rician K- Factor in this model: I know that if $K=0$ then it is a pure Rayleigh fading, if $K= \infty$, then non fading Channel. What is it, if $0<K<\infty$ ? If i represet ...
1answer
41 views

### Channel estimation

In single-carrier systems, at the receiver, when we need to do channel estimation and equalization? Do we need to do before timing synchronization and CFO correction or before it? And, please let me ...
1answer
42 views

### Designing Rayleigh Fading Wireless Channel with particular properties [closed]

I have some information on particular wireless channel between an Access Point(AP) and K users as described in the picture below: How i can create this channel in Matlab?
2answers
70 views

0answers
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2answers
753 views

### Correct way to simulate Rayleigh fading for indoor environments

I am trying to simulate indoor communications with all components included. But something disturbs me when it comes to Rayleigh fading part. I am adding my rayleigh fading to the transmitted signal ...
1answer
214 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 ...
0answers
46 views

### Actual measurements of the influence of fading and multipath on HF radio communication

I'm looking for papers or books that contain actual measurements of the influence one has to expect in HF radio communication. I'm interested in this, because i've simulated the influence of a ...
2answers
293 views

### Why do we express complex noise as Gaussian distributed while the channel is Rayleigh distributed?

I have a confusion regarding the distribution of noise and channel fading. As we know channel fading is usually modeled with Rayleigh fading since it has Gaussian distributed real and imaginary ...