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63 Threads found on edaboard.com: Channel Impulse Response

channel simmulation and design

Hi friends, can you send me matlab code to find impulse response and tapped delay model. with example. Please friends help to me.. i need urgently.

The Impulse Response of a Wireless Fading Channel

Hello, According to Proakis, the equivalent low-pass impulse response of a multipath fading channel is given by: c(\tau;t)=\sum_n\alpha_n(t)\,\delta(\tau-\tau_n(t))\,\text{e}^{-j\theta_n(t)} The question is: where does the variable \tau come from? Thanks in advance

how to simulate MIMO channel in matlab

Hi all, Ive got a question, how to implement the MIMO channel if I have a TDL (CIR of the multipath channel) and i have correlation matrices of terminal and BS. So the spatial correlation matrix is kron(R_bs, R_term). So I have the output signals from both or more antennas, i have the multipath channel impulse (...)

Problem in Channel Estimation using Least Square Approach

I have pilots which are either +1 or -1, (bpsk modulated). I am using OFDM . After passing through rayleigh channel and than adding noise, i am trying to estimate thr channel. Simplest way is the least squared approach , do (Y/X) to get H_ls (least squared impulse response in freq domain). note : this is done after doing (...)

Calculating frequency resonse in Matlab

hi, Can anyone tell me how to calculate the frequency response of a channel given the impulse response of the channel? Should I just use the fft function? I have used the function freqz(b,a,f,fs) but I dont know if I did it right. What should be the duration of the frequency response? (...)

urgent matlab help confuse.....

You have said it urself...the 1st command gives u the channel impulse response (A RANDOM VARIABLE), whereas the other command resturns the DISTRIBUTION itself...i use the following code to generate the channel: %Rayleigh fading a = sqrt(0.5)*( randn( 1, symbols_per_frame) + j*randn( 1, symbols_per_frame) ); % complex (...)

simulation of em algorithm for CIR estimation

hi dears, i need to simulation of em algorithm for channel impulse response estimation for uwb channels and i dont want to use these methods(e.g. calman filter and etc) please send to me a matlab code concerned it

Need em algorithm channel impulse response estimation

hi, i need to simulation of em algorithm for channel impulse response estimation please send to me

a simple question on adaptive filtering

Wiener filtering is an optimal filtering against noise, when stohastic properties of signal and noise are provided LMS is linear channel identification algorithm. For given determenistic input and output signal we can determine impulse response of linear transform No similarity (except mean squared error criteria used)

Looking for Matlab code for LMS and RLS

Here is the LMS and RLS matlab codes..... LMS xLen = 2000; %sequence length hLen = 10; %filter length sigma_w2=0.0; %AWGN power D=0; delta=0.06; c = ; %channel impulse response x = rand_sym(sqrt(2), xLen+200, 1); %x=real(x); d = ; %take delay into consideration y = conv(x,c); %y(1:D)=; %ta

Explain me the Time Diversity concept

channel impulse response for the faster one varies faster so you have lower coherence time and consequently more diversity

UWB impulse response for UWB indoor channel

Hi all, I am planning to simulate uwb channel. any idea what impulse response should be taken for uwb indoor channel.? Slither

Simulate OFDM in IEEE 802.16 using MatLab

The estimated channel impulse response (CIR) can be calculated as follows: h(i)=x(i)L(i) where i = 0, 1, ... , 51. x(i) input signals OFDM-preamble L(i) - long training symbol include 52 subcarriers L = {1,1,-1,-1,1,1,-1,1,-1,1,1,1,1,1,1,-1,-1,1,1,-1,1,-1,1,1,1,1,

Help me model ISI channel in Matlab

Hello, If I have a channel impulse response like δ(t) + 2*δ(t-Ts), how can I model this in Matlab? I realized it should be like h= or sth like that. But I do not know what the matrix elements mean. Can anyone help me? Thanks...

Theory of the Gaussian channel

As far as I am concern, the impulse response depends on the transfer function of the channel and it is deterministic, it has noting do do with noise in the channel that is random. If you try to have a impulse response considering noise you will come across a stochastic system and believe (...)

Impulse response of fading channel and channel estimation

I am facing very fundamental problem in channel estimation in wireless communication. In channel estimation we usually find the impulse response of channel. But what will be the impulse response of frequency flat/selective fading channel (time (...)

Cyclic Prefix in OFDM

Cyclic prefix is used to avoid intersymbol interference(ISI) which is a common phenonmenon in frequency selective channel. Usually length of the CP is kept greater or atleast equal to the length of the channel impulse response.

problem regarding ofdm demodulation

hi, i am working on the synchronisation of dab receiver in which ofdm technology is used. I removed the coarse and fine frequency offsets by running a nco. I also synchronised the fft timing window with the peak of channel impulse response at the zeroth index. Now i differentially decode the received ofdm symbols with the previous ones. In (...)

frequency domain equalization

Conventionally, if equalization is carried out in time domain, matrix inversion is involved. However, if the channel has long impulse response, the computational complexity of calculation matrix inversion is very high, making it impossible for practical applications. We recall that the received signal is the linear convolution of (...)

Channel environment, impulse response question

Hello! I have implemented in matlab some classical channel equalization methods (I used AWGN,BPSK). I have to make BER vs SNR simulations and should do this in different channel environments (rural, hilly, urban..etc). I'm looking for the corresponding impulse response values for them, but so far I didn't find any. (...)