Hi at all
I have to descrived in vhdl a rate generator with a NCO.
I have a phase increment (2^32)*fo/fi (where fo is the frequency
I want and fi is the core frequency
Electronic Elementary Questions :: 16.06.2004 09:20 :: Charlie.za :: Replies: 2 :: Views: 1808
I tested your signal, it had a small bug.
sampling frequency to symbol rate ratio must be integer. e.g. if you want to keep sampling frequency in 8000 you can specify 8000/6 = 1333 or 8000/5 = 1600 to symbol rate.
Hope these helps.
Digital Signal Processing :: 15.08.2005 09:43 :: mahdithdn :: Replies: 2 :: Views: 3041
i have simulated a code in matlab for the demodulation of ofdm signal (dab). In the synchronisation process, i found the clock offset of 13.035 khz in the spectrum after downconversion. i used a nco to remove the frequency offset. Now when i differentially decode the symbols, i get 5th and 6th symbols (...)
Digital Signal Processing :: 12.05.2006 03:45 :: shameem :: Replies: 0 :: Views: 1315
I am writing a BPSK demodulator using VHDL for a Xilinx Vertex2 Pro
FPGA. I will be getting IQ data on which I'll do the demodulation.
However, the IQ data has varying phase and frequency offsets which need
to be corrected before hard decision decoding can be carried out.
Has anyone implemented frequency and phase offset (...)
PLD, SPLD, GAL, CPLD, FPGA Design :: 22.06.2006 09:55 :: abhisheknag :: Replies: 1 :: Views: 926
this type of code is hard to find, because the code generally is proprietary.
Does any one have a working Verilog code/ algorithm for envelope detection, phase discriminator and/or frequency discriminator? I already have a working code for demodulation of ASK and FSK but i dont think (...)
PLD, SPLD, GAL, CPLD, FPGA Design :: 14.06.2007 09:25 :: funster :: Replies: 2 :: Views: 1886
i need matlab code for filter in fm demodulation.
the basic problem is dat i could find codes but nowhere they were using the modulated signal foer filteration. they just took the specifications as sampling rate and cutoff frequency etc. but as is the case we have to pass the I and Q componens of the signal through the (...)
Microcontrollers :: 29.05.2009 01:25 :: fishurpocket :: Replies: 0 :: Views: 1076
If you have matlab installed on your computer you can search with its help, for example see the following:
y = fmmod(x,Fc,Fs,freqdev)
y = fmmod(x,Fc,Fs,freqdev,ini_phase)
y = fmmod(x,Fc,Fs,freqdev) modulates the message signal x using frequency modulation. The carrier signa
Digital communication :: 24.08.2009 16:10 :: Aya2002 :: Replies: 13 :: Views: 6477
Hi, I have a matlab code here
it acquires FM modulated signal from sound card can perform FM demodulation
however, i don't why it set vcok (VCO K constant) at 0.176
anyone can explain to me how and why it is set to 0.176?
Fc = 2144; %select VCO carrier frequency
vcok = 0.176; %select vco constant
Fs = 40000; %select sound (...)
Digital communication :: 06.09.2009 09:47 :: yiyi87 :: Replies: 0 :: Views: 3267
hi i need help in writing the demodulation code for the FSK system below any help would be appreciated. cause i have no idea how to move forward with this
if nargin > 3
error('Too many input arguments')
Digital communication :: 03.11.2009 15:34 :: lynx_z3 :: Replies: 1 :: Views: 3201
Find the matlab code below:
bit = round(rand(1,10)); % bit stream of random 1's and 0's
bitperiod = 0.01; %bit period
fs = 15000; %sampling frequency
fc = ; % carrier frequency
% create the FSK signal
transmitted = zeros(1,L);
for k = 1:length(bit)
f = fc(bit(k) + 1);
Digital communication :: 12.11.2009 01:08 :: mohanag :: Replies: 1 :: Views: 5739
Guess your frequency deviation (50 in the fmmod call) is too little at GHz range for it to be detected, if you increase it to a a few 10s of Mhz, then it'll work.
50/2Khz = 2.5%, In comparison, 50/2Ghz is nothing
Digital communication :: 16.12.2009 10:00 :: bulx :: Replies: 3 :: Views: 919
i am having problem in plotting the demodulated signal, graph shows nothing, can anyone help....
and further , How to calculate BER?
Here is the code......
clear; % Clear all stored variables
Ns=100; %Number of data bits
NRZ=2*data-1;% Converts 0 t
Digital Signal Processing :: 08.04.2011 10:35 :: w_bwr :: Replies: 0 :: Views: 428
I modified the following matlab code for QPSK to use it in frequency offset analysis
%N=100000; % number of bits
N = 2*100000;
F_Offset =; % multiple frequency offset values
for x= 1 :length(F_Offset) % frequency Offset
% Input Data Generation (...)
Digital communication :: 03.09.2011 03:53 :: ReComm :: Replies: 1 :: Views: 1559
Hello everyone!!! I have a problem. I would like to perform phase demodulation using PLL. I have some matlab code that do that in the case of FM. Here is the code:
%This m-file demonstrates a PLL which tracks and demodulates an FM carrier.
RF, Microwave, Antennas and Optics :: 02.11.2011 07:11 :: FFFPLL :: Replies: 0 :: Views: 669
i have made this after all by myself ... some help from some respectful source....
here it is ...
%Single SideBand Modulation
%By Naveed Ahmad Chughtai
N = 1024;
fs = 2048;
ts = 1/fs;
%t = (0:ts:1);
fc = 600; %Carrier frequency !! Limit fc<800 to avoid freqdomain aliasing
fm1 = 200;
Em1 = 1;
m = Em1*cos(2*pi*fm1*t);
Digital communication :: 10.12.2011 05:54 :: chughtai134 :: Replies: 1 :: Views: 3448
I am trying to implement an Amplitude shift Keying ASK modulation and (synchronous)demodulation in Matlab,I have to use a PLL at the receiver end for demodulation.The task is to read a hexadecimal file (attached) and convert it to a binary stream. the binary stream is the modulated with a carrier frequency of 30,000 Hz. The (...)
Digital Signal Processing :: 18.12.2011 08:31 :: ultraviolet_ray :: Replies: 0 :: Views: 1088
what is cpfsk
fsk frequency shift kaying
Digital communication :: 09.01.2012 03:39 :: shahbaz.ele :: Replies: 1 :: Views: 1198
I have written a matlab code for fsk modulation...the explanation of my code is first I have generated a random sequence. Then i have compared that with threshold. If the number is greater than or equal to threshold then we assign that number to 1 else we assign the number to 0. Thus we get a binary sequence. If the bit is equal to 1, the f
Digital communication :: 19.01.2012 00:18 :: Shruti01 :: Replies: 3 :: Views: 1320
I have written a matlab code for fsk using bandpass filter but I m not getting correct code is as follows:
threshold = 0.5;
Tb = 1; % Bit duration
fc = 3/Tb; % Carrier frequency
t1=linspace(0, 1, no_of_samples);
Digital communication :: 25.01.2012 00:36 :: Shruti01 :: Replies: 0 :: Views: 1119
I have written a matlab code for ask modulation and demodulation. I have taken 1 bit at a time, modulated tat bit, added noise to it and demodulated that bit to recover the original data bit. I need to modify this code for all the bits present in the data sequence.... I have to repeat the above steps for 10 bits... How to do tat.. (...)
Digital communication :: 03.02.2012 02:24 :: Shruti01 :: Replies: 2 :: Views: 1433
It depends on the ADC. If it has an SPI interface then u need an SPI on the FPGA which u could find ready in EDK or on the internet (opencores.org). If the ADC will be connected to the FPGA in parallel, then u don't need an interface u can just read the inputs directly. Other details on the operation of the ADC should be in the datasheet, like the
PLD, SPLD, GAL, CPLD, FPGA Design :: 06.02.2012 09:22 :: am85 :: Replies: 2 :: Views: 2399
the PLL is a phase locked loop , it has many application and many configrations , it may used in demodulation of FM and FSK or it can be used in clock and data recovery circuits
it consists of 1) phase detector
2) loop filter
and may contain a divider
the frequency Synthesizer is a ci
RF, Microwave, Antennas and Optics :: 18.03.2004 10:18 :: khouly :: Replies: 2 :: Views: 1182
My code is as follows:
ka=0.1; %% 0demodulation
Digital Signal Processing :: 30.07.2009 07:19 :: ashwini1 :: Replies: 0 :: Views: 721
This is also related to the ambiguity function of a code. CDMA codes are usually chosen to have low correlation to other codes. Ambiguity also takes into account the equivalent effect of a frequency offset between codes. just as time shifts cause codes to be partially correlated to other (...)
Digital communication :: 14.08.2011 15:30 :: permute :: Replies: 3 :: Views: 598