节点文献
低压电力线全双工通信网络的研究
Study on Full-duplex Communication for Low Voltage Power Line Network
【作者】 曹亮;
【导师】 李红信;
【作者基本信息】 兰州大学 , 通信与信息系统, 2013, 硕士
【摘要】 低压电力线通信是独特的也是未来通信发展前景广阔的通信方式。目前国内载波芯片的调制解调技术已经齐头并进,不存在什么优劣差异,但性能上的差异还是很大,关键还是看如何处理发送和接收的方式,没有不好的调制技术,只有不好的实现算法。由于现有的载波芯片没有MAC层功能,需要软件来实现,加上通信速率低以及通信条件时变,所以在载波侦听时检查到无节点使用网络,实际是其它节点载波侦正在线上,只是尚未到达或不能到达侦听节点。以上原因导致组网时间过长,如果网络中除信标帧外,还有其它数据帧时,问题变得更为复杂。针对上述问题,本文提出低压电力线全双工通信组网模型,来提高组网及通信效率。首先,本文全面阐述了低压电力线信道的传输特性、干扰和衰减特性,以及低压电力线网络拓扑结构的复杂性和实时性,指出低压电力线通信网络的组网功能和组网要求。分析现有的调制解调芯片在三相电网的某一相上,采用同频率的半双工通信,所以在这种方式下,即使采用上述较为先进的分布式组网和动态分簇路由算法时,MAC层的协调和控制机制非常复杂,导致组网时间过长。建立低压电力线全双工通信系统模型,为后续的工作提供依据。然后,低压电力线全双工通信网络采用基于IP组网方法能够使同一台变下、同一相线上、以及能够可靠通信的低压电力线通信节点,构成一个IP子网。不能可靠通信的节点,分属于不同的子网,依靠子网之间的网关节点通信。两个子网之间的网关节点是由多个节点构成的网关簇,达到可靠通信的目的。同时通过制定合适的重路由算法就可使全双工通信方式在保证低压电力线通信网络的稳定性及通信抗毁性要好于传统星形网络拓扑,并基于OPNET平台搭建网络通信模型进行验证。最后,分析低压电力线通信网络的网络性能,考虑低压电力线用户终端工作方式有半双工和全双工的区别,导致电力线信道资源利用上一个属于单信道,另一个属于双信道。利用排队理论可知对应的网络性能模型一个是单服务器队列,另一个是双服务器队列。基于OPNET平台构建这两种排队网络模型,给出性能评价分析,通过验证可知低压电力线全双工通信网络的性能是最优的。
【Abstract】 Low voltage power line communication is unique and future development prospect of the communication. At present chip domestic carrier demodulation technology goes hand in hand. There is no quality difference, but the performance difference is very big still. The key is to see how to deal with sending and receiving way. There is no bad modulation technology, only the implementation of the algorithm. Chip without the MAC layer due to the existing carrier function, need software to realize, and low communication rate and time-varying communication conditions, so the carrier check when listening to no node using the network, the actual carrier is other node mapping is online, but has not yet arrived or not to listen. These reasons lead to networking time is too long, if the network in addition to the beacon frame, there are other data frame, the problem becomes more complicated. According to the above problem, this paper proposes low-voltage power line full-duplex communication network model, to improve the efficiency of networking and communications.First, this paper comprehensively expounds the transmission properties of low-voltage power line channel, interference and attenuation characteristics, and the complexity of the low-voltage power line network topology structure and real time, points out that the network function of low voltage power line communication network and network requirements. Points out that the existing modulation demodulation chip on one phase of three-phase power, using the same frequency half duplex communication, so in this way, even with the relatively advanced distributed networking and dynamic clustering routing algorithm, the MAC layer of the coordination and control mechanism is very complex, result in network time is too long. Low voltage power line full-duplex communication system model is to provide the basis for the follow-up study.Then, low-voltage power line full-duplex communication network based on TCP/IP networking method can make the same phase and reliable communication by low voltage power line communication nodes constituting an IP subnet. Not reliable communication nodes and points belong to different subnets rely on communication subnet gateway between nodes. The gateway node between the two subnets are composed of multiple nodes gateway cluster, achieve the goal of reliable communication. At the same time by making appropriate routing algorithm can guarantee the stability of low-voltage power line communication network and make communication anti-destroying ability better than traditional star network topology and set up network communication model based on OPNET software simulation.Finally, for the low voltage power line user terminal works with half-duplex and full-duplex difference, lead to resource use on a power line channel belong to single channel, another belongs to dual channel. Using queuing theory, the corresponding network performance model is a single server queue, the other one is double the server queue. Both queuing network model was constructed based on the OPNET platform, gives analysis to the performance evaluation, by verifying known of low-voltage power line full-duplex communication network performance is optimal.
【Key words】 full-duplex communication network of low voltage power line; networking; network reconfiguration; frame;