隧道无线协作通信系统容量与性能优化

发布时间：2018-10-12 19:50

【摘要】：隧道空间受限、狭长且存在分支、弯道和坡道等情况,电磁波在其中传播的多径衰落效应严重,是制约隧道无线通信系统性能的关键问题。协作通信能够在不增加各个节点天线数量的前提下,利用隧道内的多径衰落,提高隧道无线通信性能。本文对隧道无线协作通信系统容量与性能优化开展研究,利用中继协作构成虚拟MIMO,增强抗多径衰落能力。首先,建立了隧道无线通信信道模型。提出通过增加隧道粗糙损耗因子,对多波模模型进行了修正,建立了综合隧道壁散射损耗的多波模修正信道模型。利用多波模修正信道模型仿真隧道内电磁波的传播特性,仿真结果与实测结果吻合度较高。对多波模修正信道模型进行简化,建立了近区模型和远区模型,并通过仿真验证了其合理性。其次,基于多波模修正信道模型,建立了隧道单中继协作通信系统模型,提出基于信道容量优化的隧道单中继协作通信功率分配方法、协作模式选择方法和中继位置选择方法。推导了AF和DF协作模式下,最大化信道容量的功率分配方法,仿真结果表明,在双重功率受限时,AF模式和DF模式下信道容量可分别提升15-38%和20-65%。提出了V-SISO和V-SIMO隧道协作通信系统协作模式选择方法。给出了不同协作模式下中继节点优化位置的计算公式。再次,建立了隧道多中继协作通信系统模型,提出隧道多中继协作通信系统的性能优化方法。在双重功率受限时,以信道容量为优化准则,基于多个中继节点参与协作,提出了AFPAGA算法和DFMKPA算法,给出了不同协作模式下功率优化分配方法。仿真结果表明,在总功率较小时,信道容量的优化效果更明显。提出了中继选择和功率分配联合优化方法,降低了隧道协作通信系统的中断概率。最后,在隧道多中继协作通信系统的中继端采用分布式波束成形,建立了隧道协作波束成形通信系统模型,提出了基于信道容量优化的隧道协作通信联合功率分配和波束成形方法,提高系统的信道容量。提出了基于预定信道功率增益门限的隧道协作通信联合中继选择和波束成形方法,在获得与所有中继节点均参与协作波束成形非常相近的信道容量和误码率的同时,降低了中继端波束成形的复杂度。论文的研究有助于提升隧道无线通信的可靠性和有效性,为灵活构建实时、长距、可靠和高效的隧道安全监控和应急救援系统提供理论支撑与技术支持。
[Abstract]:The tunnel space is limited, narrow and there are branches, bends and ramps, and so on. The multipath fading effect of electromagnetic wave propagating in the tunnel is serious, which is the key problem to restrict the performance of the tunnel wireless communication system. Cooperative communication can improve the wireless communication performance of tunnel by utilizing multi-path fading without increasing the number of antennas in each node. In this paper, the capacity and performance optimization of tunnel wireless cooperative communication system is studied. Virtual MIMO, based on relay collaboration is used to enhance the anti-multipath fading capability. Firstly, the tunnel wireless communication channel model is established. By increasing the rough loss factor of the tunnel, the multi-mode model is modified, and the multi-mode modified channel model is established to synthesize the tunnel wall scattering loss. The propagation characteristics of electromagnetic wave in tunnel are simulated by using multi-mode modified channel model. The simulation results are in good agreement with the measured results. The multimode modified channel model is simplified, and the near region model and the far region model are established, and the rationality of the model is verified by simulation. Secondly, based on the multi-mode modified channel model, a tunnel single-relay cooperative communication system model is established, and a tunnel single-relay cooperative communication power allocation method, cooperative mode selection method and relay location selection method based on channel capacity optimization are proposed. The power allocation method for maximizing channel capacity in AF and DF cooperative mode is derived. The simulation results show that the channel capacity in AF mode and DF mode can be increased by 15-38% and 20-65% respectively under dual power constraints. A method for selecting cooperative mode of V-SISO and V-SIMO tunneling cooperative communication systems is proposed. The formula of optimal location of relay nodes in different cooperative modes is given. Thirdly, the model of tunnel multi-relay cooperative communication system is established, and the performance optimization method of tunnel multi-relay cooperative communication system is proposed. In the case of dual power constraints, the AFPAGA algorithm and the DFMKPA algorithm are proposed based on the channel capacity optimization criterion and multiple relay nodes participate in the cooperation, and the optimal power allocation methods in different cooperative modes are given. The simulation results show that the channel capacity optimization effect is more obvious when the total power is small. A joint optimization method of relay selection and power allocation is proposed to reduce the outage probability of tunnel cooperative communication system. Finally, the distributed beamforming is adopted at the relay end of the tunnel multi-relay cooperative communication system, and the model of the tunnel cooperative beamforming communication system is established. A joint power allocation and beamforming method based on channel capacity optimization is proposed to improve the channel capacity of the system. A joint relay selection and beamforming method for tunnel cooperative communication based on predetermined channel power gain threshold is proposed. The channel capacity and bit error rate (BER) which are very similar to those of all relay nodes involved in cooperative beamforming are obtained. The complexity of beamforming at the relay end is reduced. The research in this paper is helpful to improve the reliability and effectiveness of tunnel wireless communication, and provide theoretical support and technical support for the flexible construction of real-time, long distance, reliable and efficient tunnel security monitoring and emergency rescue system.
【学位授予单位】：中国矿业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD65

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