基于叠加调制策略的改进型协作分集方案

Improved Cooperative Diversity Schemes Based on Superposition Modulation Strategies

  • 摘要: 在无线传感器网络(WSN)中,协作分集是一种至关重要的技术。采用该技术,可利用WSN中冗余节点多的特性,用户间共享彼此的天线;从而,不仅可获得空间分集增益,而且可提高系统的吞吐量和抗衰落特性。但是,WSN中节点间如何进行协作,尤其是接收端如何译码以达到更高效的数据传输,仍然是一个值得进一步研究的问题。本文在传统传输方案的基础上引入了叠加调制策略。利用该策略,首先从节点间的链路状态和能量匹配的角度设计新型的符号映射算法,然后从信噪比和误码率方面考虑接收端的译码问题。与无协作方式、译码转发协作方式相比,这一优化算法不仅解决了传统协作方式的时隙利用率只有直通方式二分之一的问题,而且减少了误码率。此外,文中还证实了新算法可比传统传输方式最多获得3dB的信噪比增益。仿真结果表明,良好的链路状态在合适能量匹配参数时不仅可以同时传输自己和伙伴的数据,而且可以权衡系统的性能。

     

    Abstract: In wireless sensor network, cooperative diversity is a very important technology, which enables users to share their antennas by using of the redundant node properties to improve space transmit diversity, also provide resistance to increase the output and channel fading effects. But how to transmit cooperatively during nodes in the wireless sensor network especially the receiving terminal node how to decode to reach a higher efficient data transmission are still some further considerable questions. The paper introduces a superposition modulation strategy based on traditional transmission schemes. By using of this strategy , firstly designs a new symbol mapping method based on the nodes’ link states and power allocation, secondly discusses the receiving terminal node’s decode problems about the signal-to-noise and bit error probability. This optimize arithmetic does not only solve one half of slot in use of the traditional cooperative mode by comparing with the no-cooperative mode and the decode-forward cooperative mode, but also decreases the bit error probability on performance. In addition, the paper proves that this new method could improve three dB of signal-to-noise at most than the traditional transmission mode. The simulation result shows that well link state with suitable power allocation not only transmits their and partners’ data at the same time, but also balances system performances.

     

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