Subspace-Based PAST Multiuser Detection Method

This program implements a subspace-based Projection Approximation Subspace Tracking (PAST) multiuser detection method within DS-CDMA communication links. The system utilizes m-sequence spreading techniques and supports transmission through both Gaussian and Rayleigh fading channels. The code can be executed directly to generate BER performance curves under different SNR conditions. The primary advantage of this approach lies in its utilization of subspace tracking technology, which effectively enhances system interference resistance while maintaining adaptability to diverse channel environments. The implementation incorporates recursive subspace estimation algorithms that dynamically track signal subspaces, along with adaptive detection weight calculation functions that optimize multiuser interference cancellation. Through this program, researchers can conduct detailed investigations of system performance under varying SNR conditions, enabling comprehensive system optimization and enhancement. The modular code structure includes separate functions for channel modeling, signal generation, detection algorithm implementation, and performance evaluation. Key computational components feature efficient matrix operations and iterative updating mechanisms for real-time subspace tracking. Additionally, this program serves educational and research purposes, assisting students in better understanding and applying PAST multiuser detection methodologies in DS-CDMA systems. The code contains commented sections explaining algorithmic steps and parameter configurations, making it suitable for both academic study and practical implementation. Welcome to use this program, and we hope it proves valuable for your research and learning endeavors.