Abstract: The authors study the transport capacity and reliability of the wireless ad hoc networks using opportunistic decode-and-forward relaying for cooperative communications when the nodes are randomly and uniformly distributed in space; meanwhile, in order to optimize the network topology, maximizing the transport capacity is applied under the connectivity of the whole networks. In the condition of the path loss and block fading channels, the authors derive the outage probability and transport capacity of the traditional relaying with opportunistic relaying and the incremental relaying with opportunistic relaying. The numerical simulation results show that, although the random distribution of nodes destroys the expected diversity gain offered by relaying nodes, the opportunistic relaying performs better than the direct communication in overcoming the channel fading. While the transport capacity of the direct communication decreases monotonically with the node density and the transmission power, the opportunistic relaying should consider the maximum transport capacity for the network topology optimization.

Key words: opportunistic relaying, outage probability, random spatial uniform distribution, networks transport capacity

摘要： 研究了节点空间随机均匀分布情况下, 采用机会中继结合解码转发方式进行协作通信的自组织网络的传输容量和可靠性。同时在保证网络连通性的前提下, 通过最大化网络传输容量, 实现网络的拓扑优化控制。在考虑路径损耗及块衰落独立信道条件下, 分别推导和分析了两节点间采用传统机会中继和增量机会中继方式下的中断概率和网络传输容量。数值仿真结果表明, 虽然空间随机分布破坏了中继节点提供的分集阶数, 但机会中继仍比直接通信有更好的抗信道衰落能力。与直接通信的网络传输容量随节点密度或发送功率单调递减不同, 机会中继需要考虑网络传输容量的极大值对网络拓扑优化的影响。

关键词: 机会中继, 中断概率, 空间随机均匀分布, 网络传输容量