Closed-form blind decoding of analog space-time codes for ultra-wideband transmissions

We propose a blind decoding algorithm for space-time block codes (STBC) tailored for ultra-wideband (UWB) transmissions. An orthogonality between signal and noise subspaces is exploited to build some quadratic form whose minimization yields the desired estimation of transmitted symbols. Simulations in lognormal fading channels show that, compared to the coherent decoding algorithm, the proposed method can achieve the same diversity; with the increment of channel coherent time, its performance approaches those of the coherent receiver.