Capacity of SISO system over a fading channel

MIMO — Capacity path 1. Intro → 2. Channel model → 3. SISO capacity → 4. Ergodic SISO → 5. MIMO capacity Tools: Shannon calculator Introduction Shannon’s formula \(C=\log_2(1+\mathrm{SNR})\) shows up in every communications course. On a fading channel the SNR itself is random, so capacity becomes a random variable. What does that mean in … Read more

Model and characterize MIMO channels

MIMO — Capacity path 1. Intro → 2. Channel model → 3. SISO capacity → 4. Ergodic SISO → 5. MIMO capacity Tools: Shannon calculator Introduction Capacity formulas and diversity analyses assume you already have a channel model. Skip that step, jump straight to \(\log\det\), and it is hard to see why correlated antennas multiplex … Read more

Introduction to Multiple Antenna Systems

MIMO — Diversity path 1. Intro → 2. Diversity vs mux → 3. SIMO → 4. Selection combining → 5. MRC Tools: Diversity & multiplexing demo MIMO — Capacity path 1. Intro → 2. Channel model → 3. SISO capacity → 4. Ergodic SISO → 5. MIMO capacity Tools: Shannon calculator Introduction to multiple antenna … Read more

Chirp signal spectrum — frequency sweep, FFT, and PSD (Matlab & Python)

Generate a linear chirp, view the spectrogram/FFT, and estimate PSD in Matlab or Python — how the instantaneous frequency sweep fills the spectrum.

Generating Basic signals – Rectangular Pulse and Power Spectral Density using FFT

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 multiple sequences of correlated random variables

In the previous post, a method for generating two sequences of correlated random variables was discussed. Generation of multiple sequences of correlated random variables, given a correlation matrix is discussed here. Correlation Matrix Correlation matrix defines correlation among N variables. It is a symmetric $latex N \times N $ matrix with the $latex (ij)^{th} $ … Read more