Resource Allocation for Multiuser Cooperative OFDM Networks: Who Helps Whom and How to Cooperate

Cooperative transmissions have been shown to be able to greatly improve system performance by exploring the broadcasting nature of wireless channels and cooperation among users. The authors focus, in this paper, on leveraging cooperation for resource allocation among users such that the network performance can be improved. Two important questions are answered: who should help whom among the distributively located users, and how many resources the users should use for cooperation to improve the performance. To answer these questions, a power-optimization, subcarrier-allocation, and relay-selection problem is formulated over a multiuser OFDM network, which is applicable to systems such as wireless LAN networks.