Direct Sequence Spread Spectrum System Simulation

In the MATLAB environment, we have developed a simulation of a Direct Sequence Spread Spectrum (DSSS) system for wireless communication over additive white Gaussian noise (AWGN) channels. This spread spectrum modulation technique encodes narrowband signals into wideband signals using pseudorandom noise (PN) sequences, significantly improving interference resistance and security. The simulation incorporates multiple real-world factors including channel fading, multipath propagation effects, and various noise interference scenarios. Key implementation aspects include: - PN sequence generation using maximal-length sequences (m-sequences) or Gold codes - Data modulation techniques (BPSK/QPSK) combined with spreading operations - AWGN channel modeling with configurable signal-to-noise ratio (SNR) parameters - Rake receiver implementation for multipath signal combining - Bit error rate (BER) calculation and performance comparison with theoretical values Through systematic analysis of simulation results including BER curves and constellation diagrams, we can evaluate system performance under different conditions and optimize design parameters such as spreading factor, modulation scheme, and receiver structure to adapt to various application scenarios.