超蜂窝架构下基于跳码的SCMA控制信道接入设计

发布时间：2018-05-12 07:50

本文选题：绿色通信 + 超蜂窝　；参考：《中国科学:信息科学》2017年06期

【摘要】：为了实现高能效绿色通信同时满足高速增长的业务量需求,未来网络将引入超蜂窝架构,通过控制与业务覆盖分离的方式实现柔性覆盖.在超蜂窝架构里,当用户有业务需求时,将免授权地随机接入控制信道发送请求信令.作为目前较为理想的随机接入方案,稀疏码多址接入(sparse code multiple access,SCMA),通过为用户分配不同码本实现非正交多址接入,从而在资源数一定的情况下提升系统的容量,允许大量用户同时接入,进而可以作为控制信道中的随机接入方式.然而,在随机接入的过程中,可能会出现采用相同码本的用户同时接入的情况,称之为码本碰撞,这会导致接收性能的恶化,并且解码算法的运算量随着码本碰撞的用户数成指数增长,严重增加了最坏情况延时.为此,本文提出一个基于时变码本的跳码方案.仿真结果表明这一新方案提升了解码准确性,进一步通过在发生严重码本碰撞时有选择地抛弃SCMA子块,可以在较低的误码率代价下大大降低整体的解码延时,从而满足控制信令高可靠、低延时的传输需求.
[Abstract]:In order to realize high energy efficiency green communication and meet the demand of high speed increasing traffic, the future network will introduce super cellular architecture and realize flexible coverage by separating control from service coverage. In a supercellular architecture, when a user has a service requirement, a request signaling will be sent to the control channel at random without authorization. As an ideal random access scheme at present, sparse code multiple access (Sparse code multiple access) can realize non-orthogonal multiple access by assigning different codebooks to users, so as to enhance the capacity of the system under the condition of a certain number of resources. A large number of users are allowed to access at the same time, which can be used as a random access mode in the control channel. However, in the process of random access, there may be simultaneous access by users using the same codebook, which is called codebook collision, which will lead to the deterioration of reception performance. Moreover, the computation of decoding algorithm increases exponentially with the number of users of codebook collision, which increases the worst case delay seriously. Therefore, this paper presents a new hopping scheme based on time-varying codebook. The simulation results show that this new scheme improves the decoding accuracy and further reduces the overall decoding delay at a lower bit error rate by selectively abandoning the SCMA subblock in the event of a serious codebook collision. In order to meet the control signaling high reliability, low delay transmission requirements.
【作者单位】：清华大学电子工程系;清华信息科学与技术国家实验室(筹);
【基金】：国家重点基础研究发展计划(973)(批准号:2012CB316002) 国家高技术研究发展计划(863)(批准号:2015AA01A701) 国家自然科学基金(批准号:61201192,61631013) 国家科技重大专项课题(批准号:2016ZX03001009) 清华大学自主科研项目(批准号:2015Z02-3)资助项目
【分类号】：TN929.5

【相似文献】