Pulse-shaping for blind multi-user separation in distributed MISO configurations

We consider a wireless system where users are equipped with one antenna each, and the antennas are spatially distributed and not physically connected. Multiple users transmit simultaneously narrowband signals using the same carrier frequency, each one using a distinct pulse shaping function with fixed bandwidth and time duration. We show that the diversity provided by the different pulse shaping functions as well as user delays and carrier frequency offsets between transmit antennas and receiver enables user separation and recovery of transmitted signals in a blind fashion, i.e., without the need for transmission of pilot symbols. The received base-band signal is over-sampled and its polyphase components are viewed as the outputs of a virtual MIMO system. The user signals are recovered through blind MIMO system estimation and equalization.