多用戶通信系統(tǒng)中編碼協(xié)同技術(shù)研究
發(fā)布時間:2018-11-27 10:52
【摘要】:協(xié)同通信融合了分集技術(shù)與中繼傳輸技術(shù)的優(yōu)勢,利用多個參與通信的實體之間的協(xié)作來共享有限資源,可有效地提高無線資源的利用率。編碼協(xié)同將編碼技術(shù)與分集技術(shù)結(jié)合應(yīng)用于協(xié)同傳輸中,有效地提高了傳輸?shù)目煽啃浴V欣^協(xié)同編碼將編碼與協(xié)同中繼結(jié)合應(yīng)用于無線通信網(wǎng)絡(luò)中,提升了用戶傳輸質(zhì)量,擴大了通信覆蓋范圍。鑒于此,本文重點研究了編碼協(xié)同分集技術(shù)和多用戶中繼協(xié)同編碼技術(shù),主要研究工作如下:1、在編碼協(xié)同中,伙伴協(xié)助用戶傳輸?shù)臄?shù)據(jù)占總數(shù)據(jù)的比例被定義為協(xié)同系數(shù),即協(xié)同的程度,它對用戶傳輸誤碼性能有著重要的影響。本文研究了多用戶模型下的協(xié)同傳輸機制,針對慢衰落信道討論了最佳協(xié)同傳輸問題。以用戶最小誤碼率為目標(biāo),求解了最佳的協(xié)同系數(shù),提出了基于“注水”法的最佳傳輸準(zhǔn)則。仿真結(jié)果表明,在慢衰落信道下,相比于均勻傳輸,本文所提出的最佳傳輸可使用戶獲得更低的誤碼率。2、信號空間分集(signal space diversity,SSD)技術(shù)可有效地獲得空間分集增益,將其應(yīng)用于協(xié)同傳輸中可充分發(fā)揮其優(yōu)勢。本文研究了多維SSD技術(shù),討論了該技術(shù)與比特交織編碼調(diào)制迭代(bit-interleaved coded modulation with iterative cecoding,BICM-ID)技術(shù)的結(jié)合。針對多用戶模型,將星座維數(shù)與協(xié)同伙伴數(shù)目結(jié)合,提出了基于BICM-ID-SSD的編碼協(xié)同傳輸方案。在快衰落信道下,相比于不采用SSD技術(shù)的方案,該方案可以獲得更高的分集階數(shù)。3、相比于傳統(tǒng)調(diào)制中的二維空間映射,多維映射可進一步提升系統(tǒng)傳輸誤碼性能。針對多用戶中繼模型,中繼節(jié)點采用多維映射技術(shù),將用戶數(shù)目與映射維數(shù)結(jié)合,可有效地提高中繼協(xié)同傳輸?shù)目煽啃浴1疚难芯苛硕嗑S映射的基本理論及具有低復(fù)雜度的解映射算法,提出了基于多維映射的中繼協(xié)同編碼,可在固定用戶傳輸整體碼率的情況下提升用戶傳輸?shù)恼`碼性能。文中針對QPSK、8PSK、16QAM等常用調(diào)制方式,給出了最優(yōu)設(shè)計下的通用中繼編碼矩陣。推導(dǎo)了快、慢衰落信道條件下用戶協(xié)同傳輸?shù)睦碚撜`碼性能,對比分析了采用中繼協(xié)同編碼與未采用中繼協(xié)同編碼兩種情況下的用戶傳輸誤碼率。理論性能與仿真性能均表明,借助于中繼協(xié)同編碼,用戶可以獲得更好的傳輸性能。4、多維乘積碼因其靈活的編碼結(jié)構(gòu)與優(yōu)異的性能備受關(guān)注,目前該技術(shù)在編碼協(xié)同中的應(yīng)用主要基于二維編碼結(jié)構(gòu)。本文研究了多維乘積碼的結(jié)構(gòu)及具有低復(fù)雜度的譯碼算法。針對多用戶中繼模型,提出了基于多維乘積碼的中繼協(xié)同編碼。中繼編碼將用戶數(shù)目、碼字?jǐn)?shù)目統(tǒng)一考慮,合理分配各維校驗比特,可在固定用戶傳輸整體碼率的情況下獲得更高的協(xié)同傳輸分集階數(shù)。文中給出了相應(yīng)的中繼編碼矩陣,并進行了誤碼性能的理論推導(dǎo)和仿真分析。與已有研究相比,由于充分利用了乘積碼的多維結(jié)構(gòu)特征,基于多維乘積碼的中繼協(xié)同編碼在傳輸分集階數(shù)上更具優(yōu)勢。5、網(wǎng)絡(luò)編碼在高效傳輸中占有重要地位,聯(lián)合網(wǎng)絡(luò)-噴泉編碼可實現(xiàn)有效傳輸?shù)耐瑫r具有良好的信道適應(yīng)性。本文針對多用戶中繼模型,根據(jù)用戶的直傳信道條件,設(shè)計了兩種聯(lián)合網(wǎng)絡(luò)-噴泉編碼的中繼協(xié)同編碼方案。針對上述方案,提出了適應(yīng)短碼長噴泉碼的聯(lián)合度分布設(shè)計方法。該方法引入分布式LT(distributed Luby transform,DLT)碼與多維LT(multi-dimensional LT,MD-LT)碼的基本思想,將用戶節(jié)點與中繼節(jié)點的度分布聯(lián)合考慮,可達到降低譯碼開銷、提高用戶傳輸效率的目的。與已有研究相比,本文所提出的聯(lián)合網(wǎng)絡(luò)-噴泉編碼的中繼協(xié)同編碼可適應(yīng)用戶數(shù)目的變化需求,具有更好的通用性及信道適應(yīng)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,
本文編號: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,
本文編號:2360484
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