Investigation of Correlated Rayleigh Fading Channel with Alamouti’s STBC-MRC system

The effect of antenna diversity for a double transmit and multiple receive antenna supported wireless communication system is investigated, that employs multi user Alamouti’s space time block coding (STBC) and maximal ratio combining (MRC) scheme on secured text message transmission. The FEC encoded Alamouti’s-MRC transmission system under investigation implements RSA cryptographic algorithm and deploys various multi-level digital modulations (16-PSK and 16-QAM) techniques over an Additive White Gaussian Noise (AWGN) and Correlated Rayleigh Fading Channels. Rayleigh channel correlation parameter ρ is varied from 0 to 0.9. It has been observed from the study that in case of without receive antenna diversity the system shows comparatively worst performance in 16PSK scheme and satisfactory performance in 16-QAM for the correlation parameter ρ=0.9. It can also be seen that the system performance is improved with increase in number of receive antenna. The performance analysis shows that with implemented Alamouti’s-MRC scheme under 16-QAM digital modulation, the system provides excellent performance over a significantly low signal to noise ratio (SNR) values.