本文選題：大規(guī)模MIMO　切入點：BDMA傳輸　出處：《東南大學》2017年碩士論文　論文類型：學位論文

【摘要】：大規(guī)模多輸入多輸出(MIMO,Multiple-Input Multiple-Output)技術(shù)可以顯著提升系統(tǒng)的頻譜效率和功率效率,是下一代移動通信系統(tǒng)的關(guān)鍵技術(shù)之一。大規(guī)模MIMO波束分多址(BDMA,Beam Division Multiple Access)傳輸方法根據(jù)波束域信道的稀疏性,通過用戶調(diào)度為不同用戶分配不同的波束集合進行傳輸,從而將多用戶MIMO鏈路分解為多個單用戶MIMO鏈路,降低了傳輸?shù)膹?fù)雜度。然而,對于實際通信系統(tǒng),完整的通信信道不僅包括空中的無線信道,也包括發(fā)射端和接收端的射頻電路。射頻電路引起的射頻增益失配會導(dǎo)致各通道間存在幅度和相位的不一致性,從而降低了 BDMA傳輸?shù)男阅堋ａ槍@個問題,本論文對大規(guī)模MIMO BDMA傳輸系統(tǒng)中通道校正方法進行了研究。全文的主要工作如下:首先,研究了收發(fā)端通道不一致性對波束域信道能量分布以及系統(tǒng)遍歷可達和速率上界的影響。分析表明,對于用戶側(cè),幅相不一致性不會導(dǎo)致波束域信道能量發(fā)生擴散,相位不一致性不改變和速率上界且幅度不一致性對和速率上界的影響很小。對于基站側(cè),幅相不一致性會導(dǎo)致波束域信道能量的擴散以及和速率上界的降低。在通常的幅相誤差范圍下,基站側(cè)相位不一致性是造成BDMA傳輸性能下降的主要原因。接著,提出了基于最小化波束域信道稀疏度準則的基站側(cè)接收通道相位不一致性校正方法。根據(jù)BDMA傳輸?shù)奶攸c,通道校正中不需要得到精確的射頻增益,校正準則可以變化為最小化波束域信道的稀疏度。在此基礎(chǔ)上,推導(dǎo)了信道稀疏度與對應(yīng)向量l1范數(shù)的關(guān)系,通過信道估計得到的上行信道信息,將最小化信道稀疏度的問題轉(zhuǎn)化為了一個最小化信道向量l1范數(shù)的問題,并給出了該問題的求解方法。仿真結(jié)果表明,提出的相位校正方法可以減小上行波束域信道的能量擴散,提升BDMA上行傳輸?shù)暮退俾市阅�。然�?提出了基于互易性校正的基站側(cè)發(fā)射通道相位不一致性校正方法,基站側(cè)發(fā)射通道的相位校正矩陣通過互易性校正矩陣與基站側(cè)接收通道相位校正矩陣的乘積得到。利用大規(guī)模天線陣列中陣元之間的互耦特性,提出了一種分組校正算法得到互易性校正矩陣。先根據(jù)天線陣列形式和互耦強度將陣元分組,分別計算每組的互易性校正參數(shù),再連接各組的校正參數(shù)得到最終的互易性校正矩陣。仿真結(jié)果表明,通過選擇合適的分組大小,提出的互易性校正方法能達到較高的校正精度�；緜�(cè)發(fā)射通道經(jīng)過校正后,BDMA下行傳輸?shù)暮退俾市阅艿玫搅孙@著的提升。最后,提出了基于信道估計的硬件校正方法。在基站側(cè)配置校正電路,控制信號使校正系統(tǒng)工作于三種不同的模式。校正系統(tǒng)工作于接收通道校正模式時,需要先進行相位補償,再使用接收到的信號計算接收通道校正矩陣。校正系統(tǒng)工作于發(fā)射通道校正模式時,各陣元發(fā)送的信號經(jīng)過定向耦合器后傳輸?shù)浇邮胀ǖ?根據(jù)接收到的信號計算發(fā)射通道的校正矩陣。完成通道校正后,校正系統(tǒng)再工作于正常收發(fā)模式。仿真結(jié)果表明,硬件校正方法具有很高的校正精度。
[Abstract]:Large scale multi input multi output (MIMO Multiple-Input Multiple-Output) technology can significantly improve the spectrum efficiency and power efficiency of the system, is one of the key technologies of the next generation mobile communication system. Large scale MIMO beam division multiple access (BDMA Beam, Division Multiple Access) transmission method according to the sparsity of channel beam domain, different beam transmission set allocation for different users through the user scheduling, and multi user MIMO link into multiple single user MIMO link, reduces the complexity of transmission. However, in the actual communication system, the communication channel end includes not only the wireless channel in the air, including RF transmitter and receiver RF RF gain. The circuit caused by mismatch will lead to the inconsistency between the amplitude and phase of each channel, thereby reducing the transmission performance of BDMA. Aiming at this problem, this paper Calibration method for large scale MIMO channel in BDMA transmission system is studied. The main contents are as follows: firstly, the transmitter and receiver channel mismatch effects on the beam domain energy distribution system and channel ergodic achievable sum rate upper bound. Analysis shows that for the user side, amplitude and phase consistency does not result in beam domain channel energy diffusion, phase inconsistency does not change and the rate of upper bound and the increase is not consistent influence on the rate and upper bound is very small. The base station side, amplitude phase inconsistency will lead to lower diffusion beam domain channel energy and rate limit. In general the amplitude and phase error range, the base station side phase inconsistency is the main reason causing the decline of BDMA transmission performance. Then, the base station side to minimize beam domain channel sparsity criterion based on the received channel phase consistency correction method according to the BDMA. The transmission characteristics of the channel does not need RF gain accurate correction, correction criteria can change to minimize beam domain channel sparsity. On this basis, to deduce the channel sparsity and the corresponding vector L1 norm, by estimating the uplink channel information of the channel, will minimize the channel sparsity problem is transformed to a minimum channel vector L1 norm problem, and gives the method to solve the problem. The simulation results show that the proposed method can reduce the phase correction of energy diffusion wave beam domain channel, enhance the BDMA uplink transmission rate and performance. Then, the base station side reciprocity correction based on transmit channels imbalance. Phase correction method, base station transmitting channel correction matrix through reciprocity correction matrix product and the base station side receiving channel phase correction matrix is obtained. By using large scale In the antenna array mutual coupling between elements characteristics, proposes a packet correction algorithm get the reciprocity correction matrix. According to the model of antenna array mutual coupling strength and the element groups, each group reciprocity correction parameters were calculated, and then the correction parameters of connection groups reciprocity final correction matrix. The simulation results show that the by grouping, choose the right size, put forward the reciprocity correction method can achieve high calibration accuracy. The base station transmit channel after calibration, BDMA downlink transmission rate and performance has been significantly improved. Finally, the correction of channel estimation method based on the hardware circuit. The correction in base station configuration, control signal the correction system works in three different modes. The correction system is in the receiving channel calibration mode, need to first phase compensation, and then use the received signal to calculate receiving channel The correction matrix. Correction system working in the transmitting channel correction mode, the signal transmitted by each element of the directional coupler and then transmitted to the receiving channel, transmission channel correction matrix is calculated according to the received signal. Complete channel calibration, calibration system working in normal mode transceiver. The simulation results show that the hardware correction method with correction accuracy very high.

【學位授予單位】：東南大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TN919.3

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