MIMO (Multiple Input Multiple Output) Y channel-based simple network coding system and method for physical layer

The invention discloses an MIMO (Multiple Input Multiple Output) Y channel-based simple network coding system and method for a physical layer. One two-skip, multi-user and multi-antenna MIMO Y channelincludes and only includes a relay node Relay of one N antenna, and includes mutual information user nodes Useri, i=1, ..., K, of K Mi antennas; all communications are realized through the Relay; thecommunications are expressed in two channels; a multi-user access channel is recorded as MAC, and a broadcast channel is recorded as BC; in the MAC, all the user nodes Useri transmit information to the Relay; in the BC, the Relay sends recoded information to the Useri; and in an MAC to BC forwarding process, the Relay realizes communication through network coding switching based on a mutual information relation matrix, a global channel information matrix and a user node pre-coding and decoding rule subscribed by a system. The invention provides a simple physical layer pre-coding matrix Vi generation rule, a simple phy