發(fā)布時間：2018-03-25 16:28

  本文選題：多輸入多輸出　切入點：預編碼　出處：《北京郵電大學》2014年博士論文

【摘要】：隨著多媒體業(yè)務和寬帶因特網(wǎng)業(yè)務迅速發(fā)展,無線用戶數(shù)量快速增長,人們對無線數(shù)據(jù)業(yè)務的要求越來越高。然而由于頻譜資源的有限性,無線通信系統(tǒng)面臨越來越嚴重的干擾。為了提高無線通信系統(tǒng)的有效性和可靠性,多小區(qū)、多用戶MIMO是無線通信研究的重點課題之一。 本文對多輸入多輸出(Multiple Input Multiple Output, MIMO)系統(tǒng)中的干擾處理技術進行了深入的研究,針對各場景設計了相應的干擾處理方案,有效地提高了無線通信系統(tǒng)的容量,降低了誤碼率。本文的主要工作及創(chuàng)新成果如下： (1)為了提高多小區(qū)MIMO下行信道和多用戶MIMO干擾信道中無線通信的有效性和可靠性,本文對空時分集的干擾對齊技術進行了研究,分別提出了多小區(qū)中空時分集的干擾對齊方案和MIMO干擾信道中空時分集的干擾對齊方案,所提兩個方案結合具體的場景,在不同時隙分別采用不同的干擾對齊方法,將每個用戶的等效信道轉變?yōu)榈刃r變信道,由此將空間分集轉換為等效信道的時間分集,并結合空時處理技術,獲得了分集增益。理論分析和仿真驗證,所提方案與原有方案相比,在獲得相同自由度的同時獲得了更高的分集增益,有效地降低了系統(tǒng)的誤碼率,提高了系統(tǒng)的可靠性。 (2)針對MIMO異構網(wǎng)絡中的分層干擾對齊方案在低信噪比條件下容量較小的問題,本文提出了一種加權最小均方誤差的規(guī)則化干擾對齊方案,所提方案利用分層干擾對齊方案的信道增益作為加權矩陣,通過迭代優(yōu)化預處理和后處理矩陣,實現(xiàn)了干擾的消除和功率的分配。理論分析和仿真表明,所提方案能通過少量迭代迅速收斂,提高了整個信噪比范圍內(nèi)系統(tǒng)的容量。 (3)為了進一步提高多小區(qū)MIMO下行傳輸?shù)挠行院涂煽啃?本文針對非線性的干擾對齊方案進行了研究,提出了一種多小區(qū)多用戶THP(Tomlinson-Harashima Precoding)的干擾對齊方案,并給出了所提方案的設計準則,所提方案利用THP構造多小區(qū)傳輸模型,通過設計合適的反饋三角矩陣、前饋矩陣和后處理矩陣,實現(xiàn)了干擾對齊,從而有效地提升了各小區(qū)的容量,降低了誤碼率。理論分析及仿真驗證,與已有干擾對齊方案相比,所提方案可以獲得更大的容量和更低的誤碼率。 (4)干擾對齊技術可以有效提高MIMO X中繼系統(tǒng)傳輸?shù)淖杂啥?然而為了實現(xiàn)完全的干擾對齊,用戶需要配置較多的天線。為了提高MIMO X中繼系統(tǒng)中在用戶天線數(shù)較小情況下的容量,本文針對MIMO X中繼系統(tǒng)提出了一種部分干擾對齊傳輸方案,推導出了MIMO X中繼部分干擾對齊的可行性條件,并給出了一種迭代的實現(xiàn)算法,所提算法能靈活適應各種用戶和中繼天線配置,可以有效地提高系統(tǒng)傳輸?shù)淖杂啥�。仿真結果驗證了所提方案的有效性。 (5)為了提高MIMO多向中繼系統(tǒng)的容量,本文研究了MIMO多向中繼的并行傳輸,提出了一種多向中繼非對稱傳輸方案,所提方案通過建立一個新的多向中繼傳輸模型,采用多天線并行非對稱發(fā)送和接收多流數(shù)據(jù),設計相應的預處理矩陣及迫零檢測矩陣消除干擾,在不增加中繼天線數(shù)的前提下,實現(xiàn)了多向中繼的并行非對稱傳輸。本文推導出了所提方案的系統(tǒng)容量,理論分析和仿真結果表明,所提方案能有效地降低了中繼的能耗,提高了傳輸效率,在多組傳輸時進一步降低了對中繼天線數(shù)的要求。
[Abstract]:With the rapid development of multimedia services and broadband Internet services, the rapid growth in the number of wireless users, the wireless data services have become increasingly demanding. However, due to the limited spectrum resources, wireless communication system is facing more and more serious interference. In order to improve the effectiveness and reliability of wireless communication systems, multi area, multi user MIMO is one of the the key issue in wireless communication research.
Based on multiple input multiple output (Multiple Input Multiple Output, MIMO) interference processing technology in the system is studied, according to the scene design the interference of appropriate treatment, can effectively improve the capacity of wireless communication systems, reduce the bit error rate. The main work and innovation are as follows:
(1) in order to improve the effectiveness of wireless communication in multi cell downlink MIMO and multi-user MIMO channel interference and reliability, interference alignment technique based on space-time diversity were studied, respectively, proposed interference alignment scheme for multi cell space-time diversity interference alignment scheme and space-time MIMO interference channel diversity, the the two scheme combined with the specific scene, using interference alignment method in different time slots, the equivalent channel of each user into equivalent time-varying channel, which will be converted to equivalent spatial diversity time diversity channel, combined with space-time processing technology, obtain diversity gain. Theoretical analysis and simulation verification, the proposed and compared to the original program, obtain higher diversity gain in the same degree of freedom at the same time, effectively reduce the error rate of the system, improve the reliability of the system.
(2) according to the hierarchical interference alignment scheme in MIMO network in the condition of low SNR small capacity problem, this paper proposes a weighted least mean square error rule of interference alignment scheme, the proposed scheme using hierarchical channel gain interference alignment scheme as the weighting matrix, by optimizing the pretreatment and after the distribution of matrix interference and power. Theoretical analysis and simulation results show that the proposed scheme can converge quickly through several iterations to improve the signal-to-noise ratio within the range of the capacity of the system.
(3) in order to further improve the effectiveness of the multi cell MIMO downlink transmission and reliability, this paper studies the nonlinear interference alignment scheme was put forward, a multi cell multi user THP (Tomlinson-Harashima Precoding) of the interference alignment scheme, and gives the proposed design criterion scheme, the proposed scheme is constructed using THP multi cell the transmission model, through the design of appropriate feedback triangular matrix, feedforward matrix and postprocessing matrix, realize interference alignment, so as to effectively improve the capacity of each cell, which reduces the error rate. Theoretical analysis and simulation results, compared with the existing interference alignment scheme, the bit error rate of the proposed scheme can obtain larger capacity and lower.
(4) interference alignment technology can effectively improve the MIMO X relay transmission system degrees of freedom, but in order to achieve interference alignment completely, antenna users need to configure more users. In order to capacity in the condition of small number of antennas to improve MIMO X relay system, according to the MIMO X relay system presents a partial interference alignment transmission scheme, deduced the feasibility conditions of MIMO X relay interference alignment, and gives the realization of iterative algorithm, the proposed algorithm can flexibly adapt to the configuration of various users and relay antennas, can effectively improve the system transmission freedom. The simulation results verify the effectiveness of the proposed scheme.
(5) in order to improve the capacity of MIMO multi relay system, this paper studies the parallel transmission of multi MIMO relay, proposes a multi relay asymmetric transmission scheme, the proposed scheme through the establishment of a new multi relay transmission model, using multiple antennas parallel non symmetric sending and receiving multi stream data, the design of preconditioning matrix zero forcing detection to eliminate the interference matrix and the corresponding, without increasing the number of relay antennas, realizes parallel asymmetric transmission of multi relay. This paper proposed the system capacity scheme, theoretical analysis and simulation results show that the proposed scheme can effectively reduce the energy consumption of the relay transmission is improved. In the groups of transmission efficiency, further reduce the number of relay antennas.

【學位授予單位】：北京郵電大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TN919.3

【參考文獻】

相關期刊論文 前1條

1 曾二林;朱世華;廖學文;;采用線性迫零接收機的多天線多用戶分集性能分析[J];電子與信息學報;2007年12期

，

本文編號：1663970