Cooperative Network Coding With MIMO Transmission in Wireless Decode-and-Forward Relay Networks

This paper proposes a cooperative network-coding (CNC) scheme for a dual-hop decode-and-forward (DF) multiple-input-multiple-output (MIMO) system, which consists of multiple source stations (SSs), one relay station (RS), and one base station (BS). Both the RS and the BS use multiple antennas, whereas the SS has only one antenna. Through a MIMO configuration between the RS and the BS, a cooperative network coded DF (CNC-DF) relay protocol is proposed to transmit the composite data flows from multiple SSs via the RS to the BS simultaneously to reduce delay and to provide network-coded cooperation gain. To demonstrate its effectiveness, CNC-DF is compared with time-division multiple-access (TDMA) DF and orthogonal space-time coded (OSTC) DF protocols. The ergodic capacity and outage probability for these three protocols are explicitly derived, showing that the proposed CNC-DF scheme can significantly improve the performance, which is closely related to the minimum of the numbers of SSs and the numbers of antennas used by the RS and the BS.