Signal Processing for Communication Systems
We live in the age of smart phones that can be loaded with numerous applications to communicate with each other. What’s next ? Where do we go from here ? Students at MIT Media Labs has answered the call with a novel approach of “Physical Telepresence” that provides the ability to remotely render shapes of … Read more
Create AWGN manually: set noise variance from SNR or Eb/N0, generate real/complex noise, and verify power — links to BER tools.
How Gold codes are built from preferred m-sequence pairs, their three-valued cross-correlation, and why they are used in CDMA/GNSS spreading.
Auto-correlation, also called series correlation, is the correlation of a given sequence with itself as a function of time lag. Cross-correlation is a more generic term, which gives the correlation between two different sequences as a function of time lag. Given two sequences $latex x$ and $latex y$, the cross-correlation at times separated by lag … Read more
Generate linear chirps, view their evolving frequency, and compute FFT/PSD in Matlab and Python — with links to basic FFT plotting posts.
Generate a Gaussian pulse, compute its FFT/PSD, and see why a Gaussian time pulse has a Gaussian spectrum.
Numerous texts are available to explain the basics of Discrete Fourier Transform and its very efficient implementation – Fast Fourier Transform (FFT). Often we are confronted with the need to generate simple, standard signals (sine, cosine, Gaussian pulse, square wave, isolated rectangular pulse, exponential decay, chirp signal) for simulation purpose. I intend to show (in a series of articles) … Read more
Generate a square wave, take its FFT/PSD, and recognize the odd-harmonic 1/n envelope predicted by Fourier series.
Matlab walk-through: sample a sinusoid, take FFT, build the frequency axis, and read peak locations — with Python twin link and FFT tool.
Generating a continuous signal and sampling it at a given rate is demonstrated here. In simulations, we may require to generate a continuous time signal and convert it to discrete domain by appropriate sampling. For baseband signal, the sampling is straight forward. By Nyquist Shannon sampling theorem, for faithful reproduction of a continuous signal in … Read more