在本篇論文中，我們根據3GPP-LTE的標準設計多天線接收系統的通道追蹤與等化器。主要包含通道響應追蹤，載波間干擾消除，與多輸入多輸出等化器，最後是硬體電路設計與確定電路字長。我們提出排序選擇機制來使多輸入多輸出正交分頻多工系統(MIMO-OFDM)的決策導向(decision-directed) 遞迴最小平方(Recursive Least Square, RLS)可適性通道追蹤演算法能在高移動環境下運作。模擬的結果證明我們提出的方法較二維(Two-Dimensional Recursive Least Square, 2D-RLS)演算法與傳統線性內插器佳。高速時變通道產生嚴重載波間干擾效應(Inter-Carrier Interference, ICI)，嚴重破壞RLS可適性演算法參考訊號的正確度，因此ICI補償是必須的。我們使用一階線性方法估計ICI係數，與平行載波間干擾消去法抵消ICI效應。在硬體設計的部分，我們使用排序漸續干擾消除法(Ordered Successive Interference Cancellation, OSIC)多輸入多輸出偵測器，其在硬體設計考量下改用QR分解取代，降低硬體複雜度。以及在ICI消去法上，做架構上改變，使運算單元下降。我們對傳統RLS可適性演算法做了兩方面的化簡，取實部運算與RLS的一次遞迴過程重新排程，故可因此大幅降低乘法器，使其可能實現在多天線接收機的硬體上。In this thesis, we discuss the channel tracking and equalization mechanisms of 3GPP-LTE downlink MIMO receivers in high mobility environments. The main blocks in the receiver include RLS channel tracking, ICI cancellation, MIMO detection. An ordered selection scheme is proposed to resist the possible error propagation due to wrong decisions in the decision-directed RLS adaptive channel tracking algorithm in 2×2 spatial-multiplexing MIMO-OFDM systems under high mobility. Simulation results show that the channel tracking accuracy of the proposed approach outperforms the 2D-RLS algorithm and the conventional linear interpolation algorithm. And due to the severe ICI effect spoils the accuracy of reference signal for our RLS adaptive interpolator. We use the first order linear approximation to approximate the ICI coefficient and utilize the parallel ICI cancellation to compensate the ICI effect. For hardware complexity consideration, we replace the architecture of the OSIC by QR decomposition. For ICI cancellation, we also reduce its complexity by hardware sharing. Moreover, with calculating real parts of the covariance matrix and the rescheduling for RLS iteration procedures, we save almost 66% complex multipliers. Therefore, the hardware implementation of a MIMO receiver supporting high-mobility is feasible.
