A Novel Transmission Scheme of Multiple Cognitive Relay Based on Network Coding
Wang Wei① Yu Li① Zhu Guang-xi① Li Hui②
①(Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China) ②(Key Laboratory of Integrated Microsystems, Shenzhen Graduate School, Peking University, Shenzhen 518055, China)
Abstract：It is already theoretically presented in previous work that multiple cognitive relay improves the throughput of cognitive networks by increasing diversity in both spatial and temporary domain. According to observation and analysis, huge amounts of redundancies exist when implementing Decode-and-Forward (DF) in a distributed relay network. To solve the issue, a so-called code-assist scheme is proposed in this paper to eliminate redundancies. By such a scheme, network coding is integrated with multiple cognitive relay. It is proved that the achievable throughput of cognitive users approaches to its theoretical upper-bound under the scheme. Moreover, this scheme also helps to decrease the effective buffer size for relay. Simulation results show that the scheme is promising and efficient.
2011, Vol. 33 
