本文選題：SCMA + 碼本分配��； 參考：《電子科技大學(xué)》2017年碩士論文

【摘要】：隨著無(wú)線通信技術(shù)的飛速發(fā)展,傳統(tǒng)的正交多址接入已經(jīng)不能滿足海量用戶接入的需求。非正交多址接入技術(shù)作為第五代移動(dòng)通信的備選多址方案,由于可以在相同的時(shí)頻資源上復(fù)用更多的用戶數(shù)據(jù)而備受矚目。稀疏碼多址接入(Sparse Code Multiple Access,SCMA)就是非正交多址技術(shù)的一種。在發(fā)送端,SCMA將比特?cái)?shù)據(jù)直接映射為從預(yù)先設(shè)定的碼本中選擇出來(lái)的復(fù)多維碼字,不同層的碼字在相同的資源上以稀疏擴(kuò)頻的方式進(jìn)行非正交疊加;在接收端,利用碼字的稀疏性對(duì)用戶數(shù)據(jù)進(jìn)行聯(lián)合檢測(cè),然后通過(guò)信道譯碼解調(diào)出相應(yīng)的比特?cái)?shù)據(jù)。與正交多址相比,SCMA可以在相同的時(shí)頻資源的情況下,極大地提高系統(tǒng)頻譜效率。本文首先介紹了SCMA的基本編碼原理和一些關(guān)鍵技術(shù),包括SCMA編碼和復(fù)用方式、SCMA多維碼本的設(shè)計(jì)、接收端經(jīng)典的檢測(cè)算法,并對(duì)兩種經(jīng)典的檢測(cè)算法進(jìn)行了仿真對(duì)比。其次,基于以上研究給出了上行系統(tǒng)容量。在此基礎(chǔ)上,針對(duì)容量最大化的碼本和功率分配問(wèn)題,介紹了一種基于信道狀態(tài)信息的碼本分配方案,但是該方案并沒(méi)有考慮用戶間干擾信息的影響。本文將用戶間的干擾信息動(dòng)態(tài)地考慮到分配過(guò)程中,提出了一種基于容量最大化的碼本分配和功率分配方案,并且與幾種經(jīng)典分配方案進(jìn)行仿真對(duì)比,仿真結(jié)果表明本文所提方案可以進(jìn)一步提高系統(tǒng)容量。最后,針對(duì)下行多用戶多輸入多輸出(Multiple Input Multiple Output,MIMO)系統(tǒng),本文對(duì)SCMA與多用戶MIMO系統(tǒng)的結(jié)合進(jìn)行了研究�；诜钦欢嘀方尤�(Non-Orthogonal Multiple Access,NOMA)在MIMO系統(tǒng)下的分簇模型,建立了SCMA系統(tǒng)的分簇模型并給出了系統(tǒng)容量;針對(duì)減少用戶簇間干擾和提高系統(tǒng)容量的目標(biāo),介紹了兩種簇間預(yù)編碼方案和一種基于信道相關(guān)性的用戶分簇方案,但是該分簇方案只適用于信道相關(guān)性高且每個(gè)簇中只有兩用戶的情況;提出了一種適用于相關(guān)信道用戶和非相關(guān)信道用戶的改進(jìn)分簇方案,該方案不僅降低了分簇的復(fù)雜度,而且對(duì)每個(gè)簇多個(gè)用戶的情況同樣適用。
[Abstract]:With the rapid development of wireless communication technology, traditional orthogonal multiple access can not meet the needs of mass access. As an alternative multiple access scheme for the fifth generation mobile communication, non-orthogonal multiple access (NOAA) technology has attracted much attention for its ability to reuse more user data on the same time-frequency resources. Sparse code multiple access (Sparse Code multiple access) is one of the non-orthogonal multiple access technologies. At the sending end, the SCMA maps the bit data directly to the complex multi-dimensional codewords selected from the preset codebook. The different layers of codewords are superposed in a sparse spread spectrum manner on the same resources; at the receiving end, The code-word sparsity is used to detect the user data, and the corresponding bit data is demodulated by channel decoding. Compared with orthogonal multiple access, SCMA can greatly improve the spectral efficiency of the system with the same time-frequency resources. This paper first introduces the basic coding principle and some key technologies of SCMA, including the design of SCMA multi-dimensional codebook and multiplexing mode, the classical detection algorithm on the receiving end, and makes a simulation comparison between the two classical detection algorithms. Secondly, the uplink system capacity is given based on the above research. On this basis, a codebook allocation scheme based on channel state information is proposed for the codebook and power allocation problem with maximum capacity, but the influence of interference information between users is not taken into account in this scheme. In this paper, the interference information between users is dynamically taken into account in the allocation process, and a codebook allocation and power allocation scheme based on maximum capacity is proposed and compared with several classical allocation schemes. Simulation results show that the proposed scheme can further improve the system capacity. Finally, the combination of SCMA and MIMO system is studied in this paper for the downlink multi-user multiple-input multiple-output (MIMO) system. Based on the clustering model of Non-orthogonal multiple access (NOAA) in MIMO system, the clustering model of SCMA system is established and the system capacity is given. This paper introduces two precoding schemes and a user clustering scheme based on channel correlation, but this scheme is only suitable for those with high channel correlation and only two users in each cluster. An improved clustering scheme for both correlated and uncorrelated channel users is proposed. This scheme not only reduces the complexity of clustering, but also applies to the case of multiple users per cluster.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN919.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 Yingmin Wang;Bin Ren;Shaohui Sun;Shaoli Kang;Xinwei Yue;;Analysis of Non-Orthogonal Multiple Access for 5G[J];中國(guó)通信;2016年S2期

2 本刊訊;;IMT-2020(5G)推進(jìn)組發(fā)布5G技術(shù)白皮書[J];中國(guó)無(wú)線電;2015年05期

3 畢奇;梁林;楊?yuàn)?陳鵬;;面向5G的非正交多址接入技術(shù)[J];電信科學(xué);2015年05期

相關(guān)碩士學(xué)位論文 前1條

1 羅艷;基于SCMA的蜂窩系統(tǒng)下行鏈路無(wú)線資源管理研究[D];西南交通大學(xué);2016年

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本文編號(hào)：2001073