Performance Comparison between OFDM and STBC-OFDM Integration

In this paper, we perform a time-domain analysis comparing the performance differences between OFDM and STBC-OFDM integration. Both OFDM and STBC are prominent technologies in wireless communications. OFDM (Orthogonal Frequency Division Multiplexing) divides high-speed data streams into multiple lower-speed substreams for transmission, thereby enhancing transmission efficiency through orthogonal subcarriers. STBC (Space-Time Block Coding) represents a multiple-antenna diversity technique that improves transmission rates and data throughput without additional bandwidth or power requirements by exploiting spatial and temporal dimensions. In our research, we compared the performance characteristics of conventional OFDM versus STBC-OFDM combined systems. Our implementation typically involves MATLAB code structures where OFDM modulation/demodulation is handled using IFFT/FFT operations, while STBC encoding employs Alamouti's code for 2x1 antenna configurations. The key finding reveals that although both technologies individually enhance wireless communication performance, the integration of STBC with OFDM further improves signal transmission rates and reliability, particularly under challenging conditions with interference and noise. This is achieved through spatial diversity gains that combat multipath fading and error correction capabilities. Therefore, we conclude that combining OFDM and STBC technologies effectively enhances wireless communication performance, especially in high-noise and interference-prone environments. Future research directions could explore advanced MIMO-OFDM implementations, adaptive coding techniques, and real-time DSP implementations to further optimize communication efficiency and reliability.