MATLAB Implementation of Energy Detection with AWGN Channel Simulation

Energy detection serves as a fundamental method in communication systems for signal presence verification. The implementation involves simulating realistic communication channels by adding Additive White Gaussian Noise (AWGN) to transmitted signals, followed by energy-based detection to determine correct signal reception. Following methodologies established in seminal papers by Urkowitz (1967), Digham (2003), and Ghasemi (2007), the MATLAB code implements a complete energy detection system in AWGN channels. The algorithm first generates original signals (configurable as single-tone or BPSK baseband signals) using MATLAB's signal generation functions like `sin()` for tones or `pskmod()` for digital modulation. The core implementation calculates appropriate noise power based on specified Signal-to-Noise Ratio (SNR) values using `awgn()` function or manual noise addition through `randn()` with proper scaling. The energy detection mechanism employs square-law detection through element-wise squaring (`signal.^2`) followed by integration (summation) over the observation window. Key algorithmic components include threshold calculation based on noise statistics using `chi2inv()` for probability of false alarm control, and performance evaluation through Monte Carlo simulations with detection probability comparisons. This implementation effectively enhances communication reliability by providing statistical validation of signal transmission integrity under various noise conditions.