Multilevel coded cooperation: Concepts and dsign criteria

This paper proposes a new coded cooperation protocol based on multilevel coded modulation for the case when the number of cooperative nodes is arbitrary. If the number of cooperative nodes is N, the proposed system makes a cooperative diversity with the multilevel coded 2^N-PAM. Multilevel coded 2^N-PAM can be decomposed into N parallel binary channels. Thus, the node can assign its own information and the other nodes´ information to respective parallel channels. The destination node decodes the information of respective source nodes using the received symbols at N consecutive time-slots. We show that the proposed multilevel coded cooperation can obtain N the diversity gain and outperform the time-division cooperative and signal superposing cooperative transmissions based on the outage probability analyses.