Distributed Testbed for Coded Cooperation with Software-Defined Radios

Evaluating the performance of the cooperative communications using the hardware testbed in the real environment is critical for system design and promoting the potential practical applications in the future, considering the disadvantages of the theoretical analysis and simulation methods. In this paper, a distributed hardware testbed using software-defined radios is designed and implemented for cooperative communications, and the performance of two coded cooperation schemes with Turbo codes is evaluated in the physical layer. For the testbed, the fundamental point-to-point link uses the differential binary phase shift keying (DBPSK) constellations, and the physical (PHY)/media access (MAC) layer frames for the performance evaluation are devised. Furthermore, a distributed node synchronization scheme is implemented and the source node and relay node work in the time division protocol without any centralized controlling. Finally, two popular coded cooperation schemes with Turbo codes for the three-node model and the four-node model are tested in the real indoor environment. The experiment results verify the effectiveness of the testbed for system performance evaluation in the PHY layer.