多用户通信系统中编码协同技术研究
发布时间：2018-11-27 10:52
【摘要】：协同通信融合了分集技术与中继传输技术的优势,利用多个参与通信的实体之间的协作来共享有限资源,可有效地提高无线资源的利用率。编码协同将编码技术与分集技术结合应用于协同传输中,有效地提高了传输的可靠性。中继协同编码将编码与协同中继结合应用于无线通信网络中,提升了用户传输质量,扩大了通信覆盖范围。鉴于此,本文重点研究了编码协同分集技术和多用户中继协同编码技术,主要研究工作如下:1、在编码协同中,伙伴协助用户传输的数据占总数据的比例被定义为协同系数,即协同的程度,它对用户传输误码性能有着重要的影响。本文研究了多用户模型下的协同传输机制,针对慢衰落信道讨论了最佳协同传输问题。以用户最小误码率为目标,求解了最佳的协同系数,提出了基于“注水”法的最佳传输准则。仿真结果表明,在慢衰落信道下,相比于均匀传输,本文所提出的最佳传输可使用户获得更低的误码率。2、信号空间分集(signal space diversity,SSD)技术可有效地获得空间分集增益,将其应用于协同传输中可充分发挥其优势。本文研究了多维SSD技术,讨论了该技术与比特交织编码调制迭代(bit-interleaved coded modulation with iterative cecoding,BICM-ID)技术的结合。针对多用户模型,将星座维数与协同伙伴数目结合,提出了基于BICM-ID-SSD的编码协同传输方案。在快衰落信道下,相比于不采用SSD技术的方案,该方案可以获得更高的分集阶数。3、相比于传统调制中的二维空间映射,多维映射可进一步提升系统传输误码性能。针对多用户中继模型,中继节点采用多维映射技术,将用户数目与映射维数结合,可有效地提高中继协同传输的可靠性。本文研究了多维映射的基本理论及具有低复杂度的解映射算法,提出了基于多维映射的中继协同编码,可在固定用户传输整体码率的情况下提升用户传输的误码性能。文中针对QPSK、8PSK、16QAM等常用调制方式,给出了最优设计下的通用中继编码矩阵。推导了快、慢衰落信道条件下用户协同传输的理论误码性能,对比分析了采用中继协同编码与未采用中继协同编码两种情况下的用户传输误码率。理论性能与仿真性能均表明,借助于中继协同编码,用户可以获得更好的传输性能。4、多维乘积码因其灵活的编码结构与优异的性能备受关注,目前该技术在编码协同中的应用主要基于二维编码结构。本文研究了多维乘积码的结构及具有低复杂度的译码算法。针对多用户中继模型,提出了基于多维乘积码的中继协同编码。中继编码将用户数目、码字数目统一考虑,合理分配各维校验比特,可在固定用户传输整体码率的情况下获得更高的协同传输分集阶数。文中给出了相应的中继编码矩阵,并进行了误码性能的理论推导和仿真分析。与已有研究相比,由于充分利用了乘积码的多维结构特征,基于多维乘积码的中继协同编码在传输分集阶数上更具优势。5、网络编码在高效传输中占有重要地位,联合网络-喷泉编码可实现有效传输的同时具有良好的信道适应性。本文针对多用户中继模型,根据用户的直传信道条件,设计了两种联合网络-喷泉编码的中继协同编码方案。针对上述方案,提出了适应短码长喷泉码的联合度分布设计方法。该方法引入分布式LT(distributed Luby transform,DLT)码与多维LT(multi-dimensional LT,MD-LT)码的基本思想,将用户节点与中继节点的度分布联合考虑,可达到降低译码开销、提高用户传输效率的目的。与已有研究相比,本文所提出的联合网络-喷泉编码的中继协同编码可适应用户数目的变化需求,具有更好的通用性及信道适应性。
[Abstract]:The cooperative communication combines the advantages of the diversity technology and the relay transmission technology, and utilizes the cooperation among the multiple participating entities to share the limited resources, and can effectively improve the utilization rate of the wireless resources. The combination of the coding technology and the diversity technology is applied to the cooperative transmission, and the reliability of the transmission is effectively improved. The relay cooperative encoding applies the coding and the cooperative relay to the wireless communication network, and the transmission quality of the user is improved, and the communication coverage range is increased. in that light of this, this paper focus on the technology of co-coding and co-coding of multi-user relay, and the main research work is as follows: 1. in the code coordination, the proportion of the data that the partner assists the user to transmit to the total data is defined as the cofactor, i. e. the degree of cooperation, It has an important influence on the transmission error performance of the user. In this paper, the cooperative transmission mechanism under the multi-user model is studied, and the optimal cooperative transmission problem is discussed for the slow fading channel. Based on the minimum error rate of the user, the best cooperation coefficient is solved, and the best transmission criterion based on the 鈥渨ater injection鈥，
本文编号：2360484
[Abstract]:The cooperative communication combines the advantages of the diversity technology and the relay transmission technology, and utilizes the cooperation among the multiple participating entities to share the limited resources, and can effectively improve the utilization rate of the wireless resources. The combination of the coding technology and the diversity technology is applied to the cooperative transmission, and the reliability of the transmission is effectively improved. The relay cooperative encoding applies the coding and the cooperative relay to the wireless communication network, and the transmission quality of the user is improved, and the communication coverage range is increased. in that light of this, this paper focus on the technology of co-coding and co-coding of multi-user relay, and the main research work is as follows: 1. in the code coordination, the proportion of the data that the partner assists the user to transmit to the total data is defined as the cofactor, i. e. the degree of cooperation, It has an important influence on the transmission error performance of the user. In this paper, the cooperative transmission mechanism under the multi-user model is studied, and the optimal cooperative transmission problem is discussed for the slow fading channel. Based on the minimum error rate of the user, the best cooperation coefficient is solved, and the best transmission criterion based on the 鈥渨ater injection鈥，
本文编号：2360484
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