How to Detect and Compensate Doppler Shift
In this article, we learn how to estimate doppler shift in a signal and also how to compensate it.
Blogs
Exploring signals, systems, and the technology around us.
What is Doppler Shift?
Doppler shift is the change in frequency of a signal caused by the relative motion between a transmitter and a receiver. This article explains what it is, derives the equation, and shows how it appears in the time domain and the frequency domain.
What is a Cyclostationary Signal?
This article discusses what a cyclostationary signal is, how it differs from stationary and non-stationary signals, with real examples and Python code to visualize the difference.
Cyclic Autocorrelation Function (CAF): How BPSK and QPSK Differ in Cyclostationary Analysis
The Cyclic Autocorrelation Function (CAF) reveals hidden periodic structure in modulated signals. This article explains what the CAF is, how to compute it, and why BPSK and QPSK produce fundamentally different CAF signatures — a difference that cannot be seen in a standard power spectrum.
What is the difference between Real Sampling and Complex Sampling
Real and complex sampling are two fundamental ways of capturing signals, each with different implications for bandwidth and spectral efficiency. This article explains how they work, where they’re used, and why complex sampling is often preferred in modern signal processing systems.
Terminologies used in Error Detection and Error Correction
Forward Error Correction (FEC) and other coding techniques use specific terms that are crucial for designing robust systems. This article explains the most important terminologies used in these techniques.
What is Reed Solomon Code?
Reed–Solomon codes are powerful error-correcting codes designed to handle burst errors by operating on symbols instead of bits. This article explains what it is and how they are used in communication systems.
What is Forward Error Correction (FEC)?
Forward Error Correction (FEC) digital signal processing technique that enhances data reliability in communication systems by allowing the receiver to detect and correct errors without needing retransmission.
Why Higher Order Modulation is less Noise‑Resistant?
BPSK and QPSK are fundamental digital modulation schemes known for their robustness to noise. Higher-order modulations, such as 16QAM, 64QAM, 256QAM offer higher data rates but are more sensitive to channel conditions. This article explores the trade-offs between noise resistance and spectral efficiency.
Why Higher Order Modulation needs High SNR?
Higher-order modulation schemes like 16QAM or 64QAM achieve high data rates but are sensitive to noise. At high SNR, the distance between constellation points is sufficient for accurate symbol detection, reducing errors and enabling reliable communication.
What is Aliasing?
Aliasing occurs when a continuous signal is sampled below its Nyquist rate, causing different frequency components to become indistinguishable. This article explains aliasing with clear examples, diagrams, and insights for signal processing applications.
Understanding I and Q - The Foundation of Signal Processing
An introduction to in-phase and quadrature signals and why this representation is useful in digital communications and signal processing.
How does your phone know you are talking?
Every time you say "Hey Siri" or "OK Google," your phone instantly recognizes that you're speaking. But how does it distinguish your voice from background noise, music, or silence? The answer lies in a technology called Voice Activity Detection (VAD), a critical component that makes modern voice assistants possible.