Cooperative Communication Method Based on Block Chain for a Large Number of Distributed Terminals

The cooperative communication of distributed terminals has many performance advantages and wide application prospects. However, it lacks effective trust foundation between distributed terminals and lacks data security guarantee. Block chain naturally has the properties of transparency, tamper-proof, and full traceability. It can effectively solve the trust problem between untrusted terminals and ensure data security. Thus, we introduce block chain into the cooperative communication of large number terminals, propose a cooperative communication method based on block chain, design a multi-chain structure to reduce resource consumption, and give the detailed working procedure of the cooperative communication method. In the working procedure, we propose a source-relay pairing and pricing scheme based on Kuhn-Munkres algorithm (SRPP-KM) to solve the optimal source relay pairing and transaction price, and design a lightweight consensus mechanism based on intra-region dynamic delegated Byzantine fault tolerant (DDBFT) and interactive updates between regional chain and main chain to reduce resource waste and achieve fast consensus. Analyses show that the proposed method can establish trust foundation between terminals and promote cooperation between terminals. Simulation results show that the proposed method can obtain higher sum revenue of sources while satisfying relays’ expected revenue and achieve faster consensus when compared with other methods.