Design of a 4x4 MIMO-OFDM Down-Link Receiver for 3GPP-LTE

李家慶(Chia-Ching Lee)

指導教授 ： 黃元豪

國立清華大學/電機資訊學院/電機工程學系/碩士(2009年)

摘要

隨著大眾對於通訊設備的需求不斷地提升，通訊設備的傳送技術持續地發展以及創新。第三代合作夥伴計畫-長期演進技術(3GPP-LTE)和移動式全球互通微波存取(Mobile WiMAX)在第四代通訊市場中，是兩大競爭對手。多輸入多輸出分頻正交(MIMO-OFDM)則是目前無線通訊主要的傳送技術。在本論文中，我們提出適用於3GPP-LTE的4x4多輸入多輸出分頻正交下傳接收器之設計，包含了分頻正交符元偵測、載波頻率偏移之估測與補償、取樣時脈偏移之估測與補償、通道估測、碼簿的選擇及多輸入多輸出解碼器。由於碼簿的選擇及多輸入多輸出解碼器有4x4矩陣乘法及除法運算，此運算有相當高的電路複雜度，因此我們使用Strassen’s演算法來簡化其複雜度。另外我們整合了可感知通道低功率快速傅立葉轉換器，此轉換器可以支援FFT大小由128點到1024點。此外，我們使用兩個FFT來處理四根接收天線的訊號，以減少硬體上的消耗。根據效能及預先編碼的效率，我們選擇MMSE-OSIC和Capacity-SC作為多輸入多輸出解碼器及碼簿的選擇標準。最後，根據cell-based設計流程，我們使用UMC 90nm cell library將系統實現到合成階段。

關鍵字

第三代合作夥伴計畫 ； 長期演進技術 ； 分頻多工 ； 多天線 ； 接收機

並列摘要

As peoples demand for communications devices continue increasing, transmission technology of communications devices is developed and created constantly. 3GPP-LTE and
Mobile WiMAX are two main competitors in the 4G mobile communication market. In this thesis, we propose the design of a 4x4 MIMO-OFDM downlink receiver for 3GPPLTE. The receiver consists of symbol decision, CFO estimation, SCO estimation, compensation, channel estimation, MIMO detection and codebook selection. Since MIMO detection and codebook selection have 4×4 matrix operations which is high complexity circuit, we use the Strassen’s algorithm to reduce its complexity. We integrate a channel-aware low power FFT processor in the system and the FFT processor can support the FFT size from 128-points to 1024-points. Besides, we use two FFT processor to process the received signal of four receive antennas in order to reduce hardware cost. According to the performance and precoding efficiency, we select the MMSE-OSIC and capacity-SC for MIMO detection and codebook selection. Finally, we use the cell-based design flow to implement the system design for gate level with UMC90nm cell library.

並列關鍵字

3GPP ； LTE ； OFDM ； MIMO ； Receiver

參考文獻

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