Widely Linear Filter Bank Equalizer for Real STBC

In this correspondence, we propose a widely linear (WL) filter bank (FB) equalizer for a real space-time block code (RSTBC) employed in a frequency-selective multiple-input-multiple-output (MIMO) channel with additive circular symmetric complex Gaussian noise. We consider a M_t-transmitting antenna (Tx)-M_r-receiving antenna (Rx) communications system with the receiver employing widely linear processing (WLP). We then analyze the perfect reconstruction (PR) condition for the induced virtual MIMO channel by WLP. Furthermore, through reducing the rate of the RSTBC, the communications system becomes a nonmaximally decimated FB which potentially leads to better equalization. Simulation results using various code rates show the proposed FB widely linear equalizer (WLE) performs better than the non-WL version.