基于DRL的定向网络时隙复用和功率控制协议
Directional Network Slot Reuse and Power Control Protocol Based on DRL
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摘要: 近年来,无人机网络逐渐地广泛应用于各行各业,对无人机网络能提供的网络容量提出了更高的要求。定向天线结合无人机网络构成定向无人机网络以增加网络资源应对无人机网络中各个节点对网络有限通信资源的竞争造成网络容量低的问题。定向无人机网络通过定向天线的空间复用能力可以提高网络的时隙利用效率。针对TDMA协议在定向组网中时隙利用率过低导致网络容量受限的问题,该文提出了一种基于深度Q网络(DQN)的定向无人机网络时隙复用和功率控制协议。为了提高时隙利用率,考虑在单位时隙进行多个链路通信以实现时隙资源的复用。然而多个链路在同一个时隙通信会产生链路间的干扰,如何在考虑链路间相互干扰的情况下控制功率提高网络的容量是时隙复用研究的重点问题。为了解决该问题,首先考虑以功率要求和每条链路最小信道容量为约束,考虑相较于其他研究更为复杂更符合实际的链路互干扰模型,建模问题为最大全网容量问题。然后为了构建链路间的更复杂的互干扰环境,将多个链路的瞬时信道信息、定向增益状态融入到DQN框架的状态中,DQN的奖励为高于最小信道容量的链路信道容量的和。最后,将每个时隙的优化问题扩展到每一帧的优化问题,并利用多个DQN进行求解。仿真结果表明,在保证每个被分配时隙的最小信道容量前提下,相较于对比方法网络容量有了很大的提升。Abstract: In recent years, unmanned aerial vehicle (UAV) networks have been progressively and extensively employed in various industries, which places higher demands on the network capacity that drone networks can provide. Directional antennas combined with drone networks form directional drone networks to address the problem of low network capacity caused by the competition for limited communication resources among nodes in UAV networks. Directional UAV networks can improve slot utilization through the spatial reuse capability of directional antennas. In response to the problem of low slot utilization and limited network capacity within directional networks employing the TDMA protocol, this study proposes a protocol for slot reuse and power control in directional UAV networks based on deep Q-networks (DQNs). To enhance slot utilization, we consider multiple links communicating in a single slot to achieve slot reuse. However, the simultaneous communication of multiple links in a single slot introduces inter-link interference. Managing power control to increase network capacity while considering this interference among links is a key focus in slot reuse research. To address this problem, we first consider imposing constraints based on power requirements and the minimum channel capacity for each link. Considering a more complex and practical link interference model compared with other studies, the problem is formulated as a maximum overall network capacity problem. Subsequently, for a more intricate inter-link interference environment, the instantaneous channel information and directional gain states of multiple links are incorporated into the state of the DQN framework. The reward for the DQN is defined as the sum of the channel capacities of links that exceed the minimum channel capacity. Finally, by extending the optimization problem of each time slot to that of each frame, multiple DQNs are utilized. Simulation results demonstrate that, while ensuring the minimum channel capacity of each allocated slot, the proposed method significantly increases network capacity compared with the benchmark methods.