Implementation of Alamouti Space-Time Coding MIMO Systems with 2×2, 4×4, and 6×6 Antenna Configurations

This MATLAB-based simulation investigates Alamouti space-time coding schemes for Multiple-Input Multiple-Output (MIMO) systems configured with 2×2, 4×4, and 6×6 antenna arrangements. The implementation involves creating orthogonal transmission matrices following Alamouti's coding principles, where transmit antennas send complex conjugate pairs of symbols across consecutive time slots to achieve spatial diversity. The simulation includes key components: signal modulation (using QPSK or other modulation schemes), Alamouti encoding module, Rayleigh fading channel modeling, maximum likelihood detection algorithm, and bit error rate (BER) calculation. For higher antenna configurations (4×4 and 6×6), the system extends the basic 2×2 Alamouti scheme through antenna grouping or orthogonal design techniques. Performance comparison curves plotting BER against Signal-to-Noise Ratio (SNR) are generated to analyze the diversity gain and system performance across different antenna configurations. The code implements SNR sweeping from 0 to 20 dB with Monte Carlo simulations for statistical reliability, using MATLAB's communication toolbox functions for channel modeling and error rate calculations.