Abstract: The rapid development of Internet of vehicles (IoV) depends on the safe and reliable infrastructure for storing and sharing large amounts of data. Blockchain, a kind of distributed data storage technology that cannot be forged and tampered with, can solve the security and privacy issues of IoV. However, the low throughput of blockchain hinders its wide application in IoV. The current research on blockchain throughput optimization has poor scalability because of its action space explosion. Aiming at the above problems, a blockchain throughput optimi-zation method in IoV based on deep reinforcement learning (DRL) is proposed to maximize the transaction throughput, and optimize the throughput of the blockchain by choosing block producers and consensus algorithms, adjusting block size and block interval while ensuring the decentralization, low delay and high security of the underlying blockchain system. This method introduces the branching dueling Q-network (BDQ) framework in DRL, carries out fine-grained division for action space, and solves the problem of action space explosion of traditional deep reinforcement learning methods. Simulation results show that the proposed method can improve the throughput of blockchain in IoV effectively.

Key words: Internet of vehicles (IoV), blockchain, throughput, deep reinforcement learning (DRL)

摘要： 区块链应用于车联网（IoV）可以有效解决车联网数据安全和隐私等问题。但是，区块链吞吐量低的问题阻碍了其在车联网中的广泛应用。已有的区块链吞吐量优化研究大都存在决策行为空间爆炸的问题，可扩展性较差。针对上述问题，提出了一种基于深度强化学习（DRL）的区块链车联网吞吐量优化方法，通过选择区块生产者和共识算法，调整区块大小和区块间隔优化区块链的吞吐量，同时保证IoV区块链的去中心化、延迟和安全性。该方法通过引入BDQ框架将行为空间进行细粒度划分，解决了区块链使用传统深度强化学习方法对吞吐量进行优化时出现的行为空间爆炸问题。仿真结果表明，提出的方法可以有效地提高IoV区块链系统的吞吐量。

关键词: 车联网（IoV）, 区块链, 吞吐量, 深度强化学习（DRL）