New MU-MIMO random access employing THP with correlation based user scheduling

This paper proposes a novel random access scheme with multiuser multiple-input multiple-output (MU-MIMO) employing Tomlinson-Harashima precoding (THP) for distributed wireless systems. An efficient user scheduling based on correlation is introduced for the proposed random access with MU-MIMO. Because the proposed scheduling does not need all channel state information from all terminals, the proposed random access enables simultaneous multiple packets transmission by using THP with small overhead. We evaluate the performance by computer simulation that the proposed access achieves about 7.8 bits/Hz at Eb/N0 = 1.3 dB when 4 antennas are installed on the access point and quadrature phase shift keying (QPSK) is applied.