基於波束選擇方法之混合式大規模多輸入多輸出收發器設計

Hybrid Beamforming for Massive MIMO Transceiver Design based on Beam-Selection Approach

洪子文(Zih-Wun Hong)

指導教授 ： 李枝宏

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201902336

摘要

基於本實驗室所提出之波束成型選擇空間預編碼(Beamforming-selection spatial precoding,BSSP)法的架構之下，為降低毫米波多輸入多輸出系統(mm-Wave multiple-input multiple-output,mm-Wave MIMO)中的硬體成本，本實驗室於先前提出了將BSSP結合傳送端之混合式預編碼(Hybrid Beamforming)的方法，而在本論文中進一步將接收端部分也運用混合式連接的架構，提出以二階段設計系統的方法，第一階段設計傳送端之預編碼矩陣(precoding matrix)，第二階段再設計接收端之接收器(combiner)參數，先以最小均方誤差(Minimum Mean-Square Error,MMSE)的解作為類比的接收器，再用第二代合作式共同粒子群最佳化法(Cooperatively Coevolving Particle Swarm Optimization,CCPSO)設計數位接收器的部分，我們發現這樣的設計方法比起只用MMSE之接收器可以有更好的效能表現。面對大規模多輸入輸出系統(Massive MIMO)中大量的天線元件伴隨著大量與射頻鏈(RF chain)之間的連線會造成傳輸過程中很多的傳輸損耗及運算成本，本論文在傳送端亦使用了部分連接(Partially connected)的架構，部分連接架構中包含不重疊子陣列(Non-overlapped Subarray,NOSA)及重疊子陣列(Overlapped Subarray,OSA)，不重疊子陣列意即每個波束群(Beam group)所連接的天線不會重疊，而重疊子陣列則是允許波束群之間所連接的天線有部分重疊，重疊子陣列架構是在全連接(Fully connected)及不重疊子陣列架構之間所做的取捨，本論文的實驗結果中將會展示不同連接方式之間的效能關係。

關鍵字

大規模多輸入多輸出系統 ； 混合式波束成型 ； 部分連接架構 ； 粒子群最佳化演算法 ； 空間預編碼

並列摘要

To reduce the hardware cost in mm-Wave multiple-input-multiple-output (mm-Wave MIMO) system, our laboratory previously proposed a Hybrid Beamforming architecture based on Beamforming-selection spatial precoding (BSSP). In this thesis, we further propose a two-step designing method used in the Hybrid Transceiver system. At the first stage, we design the analog precoding matrix as previous research in our laboratory. At the second stage, we use the Minimum Mean-Square Error(MMSE) solution as the analog combining parameters and use the second generation of Cooperatively Coevolving Particle Swarm Optimization (CCPSO2) to design the baseband combiner. We have found that using hybrid structure at the receiver side in our system can have better performance than only using MMSE solution for the combiner. Massive MIMO system equips a large number of antenna elements and links between antennas and RF chains that will cause a lot of transmission loss and high computation complexity. In this thesis, we used partially connected structure at the transmitter side. There are two kinds of partially connected structure, Non-overlapped Subarray(NOSA) and Overlapped Subarray(OSA). Non-overlapped Subarray means that the antennas connected by each Beam group do not overlap. Overlapped Subarray means that each Beam group’s connected antenna allows partial overlap. Overlapped Subarray can be seen as a trade-off between fully connected and Non-overlapped Subarray. The simulation results of this thesis will show the performance relationship between different connection methods.

並列關鍵字

Massive multiple-input-multiple-output system ； hybrid beamforming ； partially connected ； particle swarm optimization algorithm ； spatial precoding

參考文獻

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