Proposal of ad-hoc multicasting based on OFDM cooperative communication

Our proposed Orthogonal Frequency-Division Multiplexing (OFDM) cooperative communication scheme achieves high performance by utilizing features of OFDM whereby receivers can jointly demodulate multiple copies of the same OFDM signal, as long as they are received within the Guard Interval (GI) period. In this paper, we describe extending the OFDM cooperative communication scheme to support a new cooperative multicast communication for wireless multi-hop networks. In the proposed multicasting method, some Forwarding Group (FG) nodes transmit the same OFDM signal at the same time to achieve cooperative communication. The results show that downstream receivers can simultaneously receive some of the same OFDM signals from different upstream transmitters, and that this improves the packet delivery ratio by means of route diversity. The numerical results show that both packet delivery ratio and delivery delay can be improved as compared to conventional Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) schemes.