Non-Coherent Broadcasting based on Grassmannian Superposition Transmission

We propose a novel construction for Grassmannian superposition transmission, which allows to transmit multiple data streams non-coherently, i.e., without channel state information at the transmitter and receiver, over single-input multiple-output block-fading channels. This scheme is suitable for multi-resolution broadcasting, as well as, for non-coherent non-orthogonal multi-user transmissions. We present a low-complexity greedy detector for this superposition scheme, as well as, a trellis detector that achieves close-to-optimal performance with significantly reduced complexity compared to maximum likelihood detection. We investigate the performance of the proposed schemes by numerical simulations, showing that the overall symbol error rate performance is very similar to existing single-stream transmission schemes, yet, at the same time supporting the transmission of multiple independent data streams using a non-orthogonal Grassmannian superposition.