Multiple Input Multiple Output (MIMO) systems have received enormous attention by researchers as they can provide a roughly linear increase in capacity of wireless communications systems by using multiple transmit and receive antennas. Even with the larger raw data rates provided by MIMO, the throughput of these systems can be limited by the number of users (or networks) sharing the medium. This paper shows how multiple users (or networks) transmitting simultaneously can be represented as a MIMO system with a larger number of transmit than receive antennas. After reviewing existing decoders for such a MIMO system, this paper then proposes applying an Asterism based decoder to distinguish between multiple users transmitting simultaneously. This produces a new multi-user access scheme that can be applied in addition to a primary access method, such as CSMA-CA.