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Hi,
I am new to MATLAB as well. My project requires me to simulate performance of Wireless Mesh Network using Smart Antenna.
I am quite new to both the topic and also MATLAB. Is there any library tools provided in MATLAB for this form of simulation?
Any help would would be appreciated.
I am eager to start, but lost as to where to start.
HI...I am doing my degree project on Sequential decoding...
Can any1 plz help me to write the Matlab codes?
actually i do understand the steps involved but i don't know Matlab..
1.generate PRBS
2.encode using convolutional encoder
3.add noise
4.sequential decoder
5.decode sequentially(hard decision-trees)
6.compare encoded bits and decoded bits
7.count number of errors
8.compute the probability of errors(BER)
I hope you'd skip the basic and move towards things that are more serious. I think every one over here is atleast good at basic Matlab, you know PhD students, ME students.
Please tell me when you start OFDM and convolutional coding in Matlab, I have some question regarding that. Also looking forward to you starting sessions of Simulink especially handling port delays
I may also share my knowledge over here, regarding Matlab and Simulink for communication systems simulation
i am doing my degree project.....
as i am proceding i had the following problems.....
can any one help me in solving the problem...
i give up advance thanks to them...
1)i need the coding to generate 128 qam signal and also sampling of 128 qam signal
2)how to covert 128 qam to 16 qam and vice versa using matlab lab coding...
please help me in order to complete the project.....
I need a help regarding my MS thesis. I have read few papers on Wimax Handover.And decided to work on wimax handover. But still i am not getting any idea on which specific topic i should work. Also i dont know how to use matlab. I have to learn it as well. Also want to know can we do wimax handover related work in Matlab? Please help me as i have short time. If you have any Handover code in Wimax? Thanks in advance.
Naina
hi hyper145: i agree with Communications_Engineer as i think we need more advance notations (i am a PhD student). When you will start an OFDM simulation?
Well i think the pace of this course z very slow ... only 1 lecture has been conducted and that also consists of basics ... i wd be better if u speed it up a little
Hi All,
I would like to put some nice examples here if this is not a problem:
Example 1: To convert a sine wave of 1 Hz analoge to digital signal of 4 digits.
-------------
clc;
close all;
clear all;
t = 0:.001:1; % Times at which to sample the sine function
sig = sin(2*pi*t); % Original signal, a sine wave
partition = [-1:2/15:1]; % Length 21, to represent 22 intervals
codebook = [0:1:16]; % Length 22, one entry for each interval
quants= quantiz(sig,partition,codebook); % Quantize.
plot(t,sig,t,quants),grid
legend('Original signal','Quantized signal');
r=de2bi(quants,'left-msb');
Example 2: To design Butterworth, Chebyshev filters and plot Bode plots, and
------------- pole/zero plot
Fs=40e3; % sampling frequency
W=[8e3, 12e3]/(Fs/2); % passband spec
[b,a]=butter(4,W,'z'); % design Butterworth
% note the order is 2*4=8
[d,c]=cheby1(4,1,W,'z'); % design Chebyshev
figure(1) % make Bode plots
freqz(b,a,60,Fs) % Butterworth in 60 points
hold on % both in the same diagram
freqz(d,c,60,Fs) % Chebyshev
figure(2) % make pole/zero plot
pzmap(b,a) % for Butterworth
figure(3) % make pole/zero plot
pzmap(d,c) % for Chebyshev
figure 1
figure 2
figure 3
Example 3: An M-Array PSK modulation
-------------
clc;
clear all;
disp('M-Array PSK Modulation')
%create a random digital message
M=input ('M= '); %alphabet size
x=randint(input('Number of binary bit stream = '),1,M);
nsample=40; %oversampling rate.
%%
%%
%use M-PSK modulation to produce y
y=modulate(modem.pskmod(M),x);
%%
%follow with rectangular pulse shaping.
ypulse=rectpulse(y,nsample);
stem(y(1:10),'filled'),grid;
%%
%%transmit signal through an AWGN Channel
ynoisy=awgn(ypulse,input('SNR in dB = '),'measured');
%%
%Create scattet plot from noisy data
scatterplot(ynoisy),grid;
%%
%Downsample at the reciever.
ydownsample=intdump(ynoisy,nsample);
%%
%Demodulate ynoisy to recover the message.
z=demodulate(modem.pskdemod(M),ydownsample);
figure;
subplot(2,1,1);
stem(x(1:10),'filled'),grid;
subplot(2,1,2);
stem(z(1:10),'filled'),grid;
%%
%Check symbole erroe rate.
[num ty]=symerr(x,z)
run the program as following:
M-Array PSK Modulation
M= 8
Number of binary bit stream = 8000
SNR in dB = 19
Okay, so I'll write a code for you when I get some free time. But I still don't understand why you want to convert 128 QAM into 16 QAM. If you have the idea adaptive modulation, then this is not the correct way to do it.
In fact we should discuss first what you want to do with the repeater... I think if you give this idea for converting, people may just reject it as it doesn't make sense. If you need 16 QAM then your modulator at the transmitter needs to be of 16 QAM and not of 128 QAM.
As far as I understand you have a repeater and for one location, the channel is static so you afford to use 128 QAM; there is lower noise for one segment of area, now for the second segment, where you are using a repeater, maybe the channel conditions are bad, so you jump to 16 QAM; less chances of error as compared to the former. However, this idea is implemented using Adaptive Modulation.
please give recommendation about simulate the systems. I mean i've never simulate even modulations because of internet resources, so i wonna write a code for ofdm transmitter.
Could you please tell me step by step procedures meaning algorithm, for example at the first we will get an input data (characters in ASCII), we have to convert it binary string, then modulation mapping (depends on modulation type QAM...), and then ifft conversion.....?
please don't kid on me! i am a freshman, i've been studying ofdm for 4 months!
I have spreaded and scrambled the data as per the WCDMA standard and as per the standard i have to pass this complex data to Root-Raised cosine filter having roll off factor 0.22.
I dont have idea how to adjust group delay parameter in it as i have not found or perhaps i dont know how to adjust it.
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i am a freshman, i've been studying ofdm for 4 months!