Abstract: The authors in this article investigated how to cancel multi-user interference with low feedback amount over 3-user multiple input multiple output (MIMO) interference channel using space-time code and precoders. Space-time block code with coding rate 2 was designed, also zero vectors were introduced into each codeword. The multi-user interference is mitigated by pre-coding at the transmitters and nonlinear operation and unidirectional cooperation link at the receivers. Compared with the existing scheme for the same scene, the proposed scheme greatly reduces feedback amount and improves the sum degrees of freedom (DOF). Simulation demonstrates the validity of the proposed scheme.

Key words: MIMO interference channel, space-time code, pre-coding, multi-user interference, feedback amount, DOF