Overcoming constructive/destructive interference in diversity transmission via Alamouti coding

We propose a novel Alamouti-Orthogonal Frequency Division Multiplexing (OFDM) system that mitigates constructive and destructive interference in practical multi-antenna wireless communications. The key innovation lies in directly applying Alamouti coding at the OFDM subcarrier level. By harnessing the inherent orthogonality and frequency-domain properties of OFDM subcarriers, our system fundamentally mitigates the constructive/destructive interference caused by propagation path-delay differences between transmit antennas. Orthogonal Frequency Division Multiplexing By discovering and leveraging the inherent properties of OFDM subcarriers-combined with the full diversity gain and inter-carrier orthogonality enabled by Alamouti coding-our system simultaneously achieves diversity gain while overcoming unavoidable multi-signal time delays inherent in diversity transmissions. Experimental results across multiple scenarios demonstrate that, under spatial misalignment, the Alamouti-OFDM system provides a maximum Signal-to-Noise Ratio (SNR) gain of 3.45 dB over traditional diversity transmission systems; in scenarios where traditional methods exhibit > 10 dB spectral fluctuations, our system confines the spectral variations of the received signal ons within 2 dB.