Differentially encoded BPSK: coherent detection

In coherent detection, the receiver derives its demodulation frequency and phase references using a carrier synchronization loop. Such synchronization circuits may introduce phase ambiguity $latex \phi = \hat{\theta}-\theta $ in the detected phase, which could lead to erroneous decisions in the demodulated bits. For example, Costas loop exhibits phase ambiguity of integral multiples of $latex … Read more

Passband Simulation Models – Introduction

For a given modulation technique, there are two ways to implement the simulation model: passband model and equivalent baseband model. The passband model is also called waveform level simulation model. The waveform level simulation techniques, described in this chapter, are used to represent the physical interactions of the transmitted signal with the channel. In the waveform … Read more

Phase demodulation via Hilbert transform: Hands-on

Analytic Signal Lab (same on every page in this path) 1. Hilbert / FFT → 2. Envelope & IF → 3. Phase demodulation (you are here) Tools: Hilbert / analytic signal demo Key focus: Demodulation of phase modulated signal by extracting instantaneous phase can be done using Hilbert transform. Hands-on demo in Python & Matlab. … Read more

Phaselock Techniques – Floyd M. Gardner [Book review]

The author, Floyd M. Gardner an influential expert in the area of PLLs, has presented a good reference book that encompasses all the theoretical and mathematical concepts for the phase locked loop (PLL) design. The collection of topics in this book provides an excellent source of information to researchers and engineers for understanding and application … Read more

Model a Frequency Selective Multipath Fading channel

Multipath & PDP (same on every page in this path) 1. Power delay profile → 2. Scattering function → 3. TDL modeling (you are here) Tools: PDP demo · 3GPP TDL A brief intro to modeling a frequency selective fading channel using tapped delay line (TDL) filters. Rayleigh & Rician frequency-selective fading channel models explained. … Read more

Histogram to PDF in Matlab — normalize bins and overlay the theoretical curve

Turn a Matlab histogram into an estimated PDF: normalize by sample count and bin width, then overlay normpdf / theoretical densities for Gaussian, Rayleigh, and exponential checks.