LINEAR
BLOCKCODES
AIM
To
detect and correct the error accruing in the transmitted data with
the help
of
linear block codes.
THEORY
A
code is said to be linear if any two code word in the code, can be
added in module 2 arithmetic to Produce a third codeword in the code.
The (n-k) bits in the remaining portion are computed from the message
bits in the accordance with the prescribed encoding rule that
determines a mathematical structure of the code, then use frame to
get the syndrome calculation.
The
hamming weight of the code vector C is defined in the number of non
zero elements in the......
ESTIMATION OF PERIODOGRAM
ESTIMATION
OF PERIODOGRAM
AIM
To
estimate the power spectral density of a given signal using
periodogram
in
MATLAB.
THEORY
The
power spectral density (PSD) of a WSS process is the Fourier
transform of the autocorrelation sequence. Periodogram is a
non-parametric method to estimate PSD
()
= (k)
For
an autocorrelation ergodic process and an unlimited amount of data,
the autocorrelation sequence may be detemined by using the time
average
(k) = (n+k)x*(n)
If
x(n) is only measured over a finite interval, say n=1,2,…N-1, then
the autocorrelation sequence must be estimated using with a finite
sum
......
SIMULATION OF BLOCK CODES HAMMING AND CYCLIC CODES
SIMULATION
OF BLOCK CODES
AIM
To
simulate linear block coding techniques for hamming and cyclic code
using MATLAB.
THEORY
HAMMING
CODES
Consider
a family of (n,k) linear block codes that have the following
parameters.
Block
length,n=2m-1
No.of.message
bits k=2m-m-1
No.
of parity bits, n-k=m, where m>=3.
These
are so called Hamming codes. To illustrate the relations between the
minimum distance dmin and the structure of the parity check matrix H.
Consider the codeword 0110100,In the matrix multiplication is done,
and the non-zero elements of this codeword “shift” out the
second,......
SIMULATION OF QUADRATURE MIRROR FILTER
SIMULATION
OF QUADRATURE MIRROR FILTER
AIM:
To
simulate the frequency response of quadrature mirror for a two
channel filter band.
THEORY:
The
QMF filter is used in the sub-band coding. This filter can be used
for reducing aliasing. This is a multirate digital filter structure
that employes 2 decimeter in signal synthesis section. The low pass
and high pass filters in the analysis section have impulse response
filters (n) and (n) respectively.
Similarly
the low pass filter and high pass filters contained in the synthesis
section have impulse response filters (n) and (n) respectively.......
FREQUENCY HOPPING SPREAD SPECTRUM
FREQUENCY-
HOP SPREAD SPECTRUM
AIM
To
simulate the frequency-hop spread spectrum modulation techniques
using MATLAB program and to calculate the bit error rate.
THEORY
Spread
Spectrum is a means of transmission in which the data of interest
occupies a bandwidth in excess of the minimum bandwidth is necessary
to send the data.
The
primary advantage of a spread-spectrum communication system is its
ability to reject interference whether it is the unintentional
interference of another user simultaneously attempting to transmit
through the channel, or the intentional interference of a hostile
transmitter......
DIRECT SEQUENCE SPREAD SPECTRUM
AIM
To
simulate the direct sequence spread spectrum modulation techniques
using MATLAB program and to calculate the bit error rate
THEORY
Spread
Spectrum is a means of transmission in which the data of interest
occupies a bandwidth in excess of the minimum bandwidth is necessary
to send the data.
The
primary advantage of a spread-spectrum communication system is its
ability to reject interference whether it is the unintentional
interference of another user simultaneously attempting to transmit
through the channel, or the intentional interference of a hostile
transmitter attempting......
Periodogram Using Python Script
Periodogram• Periodogram is the correct name for thefollowing process*:
• FFT stands for “Fast Fourier Transform”• The FFT algorithm that can be used tocompute thepart.• A periodogram is formed after taking theaverage magnitude squared of the FFT.
Periodogram: Simple Example
1.n = integer2.N = array of numbers from 0 to 2^n3.x = exp(j*2*pi*f*N) + white noise4.pg = abs(FFT)^2 / n5.pgs = 10*log10(pg)
•Calculates spectrum from Real/Imagaxis,......
Solving a Linear Systes of Equations Using python
Solving linear systems of equations is straightforward using the scipy
command linalg.solve. This command expects an input matrix and
a right-hand-side vector. The solution vector is then computed. An
option for entering a symmetrix matrix is offered which can speed up
the processing when applicable. As an example, suppose it is desired
to solve the following simultaneous equations:
We could find the solution vector using a matrix inverse:
However,......
How to backup your android phone using Ubuntu
Android backup
If not enabled, enable developer mode by tapping Settings > About phone > Build number (7 times)
If not enabled, enable USB debugging in Settings > Developer options > USB debugging
Execute on your computeradb backup -apk -shared -all
This should hopefully create backup.ab with all of your apps, OS, and data. Later, after reflashing with Android (or rooting / unlocking) you will be able......
How to Install UBUNTU in Android Phone
Installing Ubuntu on a phone
Ubuntu 13.10 Saucy Salamander released with a new smartphone experiance . just try it out if you have a an androind smartphone
Instructions for flashing a phone or tablet device with Ubuntu.
After you install Ubuntu for phones, you will have the following functionality:
Shell and core applications
Connection to the GSM network on Galaxy Nexus and Nexus 4
Phone calls and SMS on Galaxy......
