MIMO中繼系統(tǒng)中基于不完全信道狀態(tài)信息的預(yù)編碼算法研究
發(fā)布時間：2019-01-04 16:58
【摘要】：多天線中繼系統(tǒng)將多輸入多輸出(Multiple-Input Multiple-Output,MIMO)技術(shù)與中繼技術(shù)的優(yōu)勢結(jié)合,可明顯提升系統(tǒng)覆蓋范圍與頻譜利用率。預(yù)編碼技術(shù)作為能進(jìn)一步提升MIMO中繼系統(tǒng)性能的關(guān)鍵技術(shù),一直被學(xué)術(shù)界廣泛關(guān)注。預(yù)編碼設(shè)計時需要獲取信道狀態(tài)信息(Channel State Information,CSI),但由于信道估計方法的局限性以及反饋鏈路的時延性,理想的CSI很難得到。本文基于不完全CSI,以改善系統(tǒng)誤碼率為優(yōu)化目標(biāo),分別對MIMO系統(tǒng)、單用戶MIMO中繼系統(tǒng)、多用戶MIMO中繼系統(tǒng)、MIMO雙向中繼系統(tǒng)的預(yù)編碼算法進(jìn)行了研究。主要研究工作如下:(1)針對MIMO系統(tǒng),考慮信道存在估計誤差及反饋延遲的不完全CSI情況,研究了基于最小均方誤差(Minimum Mean Squared Error,MMSE)準(zhǔn)則的預(yù)編碼算法。介紹了求解約束優(yōu)化問題時采用的拉格朗日乘子法和無約束優(yōu)化問題時采用的求導(dǎo)法,以及通過交替迭代實(shí)現(xiàn)聯(lián)合優(yōu)化的聯(lián)合迭代法,為MIMO中繼系統(tǒng)的預(yù)編碼算法研究打下基礎(chǔ)。(2)針對單用戶MIMO中繼系統(tǒng),考慮信道存在估計誤差及反饋延遲的不完全CSI情況,提出了基于MMSE準(zhǔn)則的預(yù)編碼算法�？紤]發(fā)射端和中繼節(jié)點(diǎn)存在功率約束的情況,通過修正因子的引入,采用拉格朗日乘子法和KKT準(zhǔn)則將求解三節(jié)點(diǎn)矩陣的優(yōu)化問題轉(zhuǎn)化為存在不等式約束的多元矩陣方程組問題,最后采用聯(lián)合迭代法交替更新得到各節(jié)點(diǎn)矩陣的最優(yōu)解。仿真結(jié)果顯示,與未綜合考慮各個節(jié)點(diǎn)的預(yù)編碼算法相比,所提算法能明顯改善單用戶MIMO中繼系統(tǒng)的誤碼率性能。(3)針對多用戶MIMO中繼系統(tǒng),在信道存在估計誤差及反饋延遲的不完全CSI條件下,提出了基于MMSE準(zhǔn)則的預(yù)編碼算法。不同于單用戶MIMO中繼系統(tǒng)的聯(lián)合求解方案,多用戶MIMO中繼系統(tǒng)預(yù)編碼算法將約束優(yōu)化問題拆分為三個包含矩陣變量的子凸優(yōu)化問題并分別求解。因?yàn)榘l(fā)送端的用戶配有單天線且服從獨(dú)立分布可先確定發(fā)送端預(yù)編碼矩陣;中繼預(yù)編碼矩陣的求解問題可轉(zhuǎn)化為SDP半正定規(guī)劃問題,利用CVX工具箱求解;接收端處理矩陣?yán)镁�性搜索法求解。最后聯(lián)合迭代得到最優(yōu)解。仿真結(jié)果表明,與未考慮中繼節(jié)點(diǎn)預(yù)編碼的算法相比,所提算法能使多用戶MIMO中繼系統(tǒng)獲得更優(yōu)的誤碼率性能。(4)針對MIMO雙向中繼系統(tǒng),在信道存在估計誤差及反饋延遲的不完全CSI條件下,以MMSE為設(shè)計準(zhǔn)則,提出了基于矩陣分解法和聯(lián)合迭代法的兩種預(yù)編碼算法。矩陣分解法通過矩陣分解和不等式理論,將矩陣優(yōu)化問題轉(zhuǎn)化為矩陣內(nèi)的標(biāo)量元素優(yōu)化問題,采用二分法求解。聯(lián)合迭代法交替更新直至算法收斂,能得到中繼預(yù)編碼矩陣、接收端處理矩陣的最優(yōu)解。與已有算法的系統(tǒng)性能仿真對比表明,所提兩種算法能有效提升MIMO雙向中繼系統(tǒng)的誤碼率性能。
[Abstract]:The multi-antenna relay system combines the advantages of multi-input and multi-output (Multiple-Input Multiple-Output,MIMO) technology with relay technology, which can obviously improve the coverage and spectral efficiency of the system. As a key technology to further improve the performance of MIMO relay systems, precoding technology has been widely concerned by academia. It is necessary to obtain channel state information (Channel State Information,CSI) in precoding design. However, due to the limitation of channel estimation method and the delay of feedback link, the ideal CSI is difficult to obtain. Based on incomplete CSI, the precoding algorithms of MIMO system, single user MIMO relay system, multiuser MIMO relay system and MIMO bidirectional relay system are studied. The main research works are as follows: (1) for MIMO systems, a precoding algorithm based on the minimum mean square error (Minimum Mean Squared Error,MMSE) criterion is studied for the incomplete CSI with channel estimation error and feedback delay. The Lagrange multiplier method and the derivation method used in solving constrained optimization problems are introduced, and the joint iteration method for joint optimization by alternating iteration is introduced. It lays a foundation for the research of precoding algorithm of MIMO relay system. (2) for single-user MIMO relay system, considering the incomplete CSI with channel estimation error and feedback delay, a pre-coding algorithm based on MMSE criterion is proposed. Considering the existence of power constraints at the transmitter and relay nodes, the Lagrange multiplier method and KKT criterion are used to transform the optimization problem of the three-node matrix into the problem of multivariate matrix equations with inequality constraints. Finally, the joint iteration method is used to alternately update the optimal solution of each node matrix. Simulation results show that the proposed algorithm can significantly improve the BER performance of single-user MIMO relay system compared with the pre-coding algorithm without comprehensive consideration of each node. (3) for multi-user MIMO relay system, A precoding algorithm based on MMSE criterion is proposed under the condition of incomplete CSI with channel estimation error and feedback delay. Different from the joint solution scheme of single-user MIMO relay system, the multi-user MIMO relay system precoding algorithm divides the constrained optimization problem into three subconvex optimization problems containing matrix variables and solves them separately. Because the user of the transmitter has a single antenna and the independent distribution of the transmitter can determine the precoding matrix of the transmitter, the solution of the relay precoding matrix can be transformed into a SDP semi-definite programming problem, and the solution can be solved by using the CVX toolbox. The receiver processing matrix is solved by linear search method. Finally, the optimal solution is obtained by joint iteration. Simulation results show that the proposed algorithm can make the multi-user MIMO relay system obtain better BER performance than the algorithm without considering the relay node precoding. (4) for the MIMO bidirectional relay system, Under the condition of incomplete CSI with channel estimation error and feedback delay, two precoding algorithms based on matrix decomposition method and joint iteration method are proposed using MMSE as the design criterion. By matrix decomposition and inequality theory, the matrix optimization problem is transformed into the scalar element optimization problem in the matrix, and the bisection method is used to solve the problem. The joint iterative method alternately updates until the algorithm converges, and the optimal solution of the relay precoding matrix and the receiver processing matrix can be obtained. Compared with the existing algorithms, the simulation results show that the proposed two algorithms can effectively improve the BER performance of MIMO bidirectional relay systems.
【學(xué)位授予單位】：南京航空航天大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN919.3
本文編號：2400550
[Abstract]:The multi-antenna relay system combines the advantages of multi-input and multi-output (Multiple-Input Multiple-Output,MIMO) technology with relay technology, which can obviously improve the coverage and spectral efficiency of the system. As a key technology to further improve the performance of MIMO relay systems, precoding technology has been widely concerned by academia. It is necessary to obtain channel state information (Channel State Information,CSI) in precoding design. However, due to the limitation of channel estimation method and the delay of feedback link, the ideal CSI is difficult to obtain. Based on incomplete CSI, the precoding algorithms of MIMO system, single user MIMO relay system, multiuser MIMO relay system and MIMO bidirectional relay system are studied. The main research works are as follows: (1) for MIMO systems, a precoding algorithm based on the minimum mean square error (Minimum Mean Squared Error,MMSE) criterion is studied for the incomplete CSI with channel estimation error and feedback delay. The Lagrange multiplier method and the derivation method used in solving constrained optimization problems are introduced, and the joint iteration method for joint optimization by alternating iteration is introduced. It lays a foundation for the research of precoding algorithm of MIMO relay system. (2) for single-user MIMO relay system, considering the incomplete CSI with channel estimation error and feedback delay, a pre-coding algorithm based on MMSE criterion is proposed. Considering the existence of power constraints at the transmitter and relay nodes, the Lagrange multiplier method and KKT criterion are used to transform the optimization problem of the three-node matrix into the problem of multivariate matrix equations with inequality constraints. Finally, the joint iteration method is used to alternately update the optimal solution of each node matrix. Simulation results show that the proposed algorithm can significantly improve the BER performance of single-user MIMO relay system compared with the pre-coding algorithm without comprehensive consideration of each node. (3) for multi-user MIMO relay system, A precoding algorithm based on MMSE criterion is proposed under the condition of incomplete CSI with channel estimation error and feedback delay. Different from the joint solution scheme of single-user MIMO relay system, the multi-user MIMO relay system precoding algorithm divides the constrained optimization problem into three subconvex optimization problems containing matrix variables and solves them separately. Because the user of the transmitter has a single antenna and the independent distribution of the transmitter can determine the precoding matrix of the transmitter, the solution of the relay precoding matrix can be transformed into a SDP semi-definite programming problem, and the solution can be solved by using the CVX toolbox. The receiver processing matrix is solved by linear search method. Finally, the optimal solution is obtained by joint iteration. Simulation results show that the proposed algorithm can make the multi-user MIMO relay system obtain better BER performance than the algorithm without considering the relay node precoding. (4) for the MIMO bidirectional relay system, Under the condition of incomplete CSI with channel estimation error and feedback delay, two precoding algorithms based on matrix decomposition method and joint iteration method are proposed using MMSE as the design criterion. By matrix decomposition and inequality theory, the matrix optimization problem is transformed into the scalar element optimization problem in the matrix, and the bisection method is used to solve the problem. The joint iterative method alternately updates until the algorithm converges, and the optimal solution of the relay precoding matrix and the receiver processing matrix can be obtained. Compared with the existing algorithms, the simulation results show that the proposed two algorithms can effectively improve the BER performance of MIMO bidirectional relay systems.
【學(xué)位授予單位】：南京航空航天大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN919.3
【參考文獻(xiàn)】
相關(guān)期刊論文 前2條
1 尤肖虎;潘志文;高西奇;曹淑敏;鄔賀銓;;5G移動通信發(fā)展趨勢與若干關(guān)鍵技術(shù)[J];中國科學(xué):信息科學(xué);2014年05期
2 張彬;賀志強(qiáng);牛凱;;MIMO中繼系統(tǒng)中的線性魯棒收發(fā)機(jī)聯(lián)合設(shè)計[J];北京郵電大學(xué)學(xué)報;2010年02期
，本文編號：2400550
本文鏈接：http://sikaile.net/kejilunwen/xinxigongchenglunwen/2400550.html
最近更新
教材專著
