用於協調式多點收發系統之非正交預編碼的功率分配

Abstract

在本論文中，我們對CoMP系統提出一套混合的預編碼方法，藉由同時使用BD與MRT兩種預編碼方法，進而降低backhaul負擔。我們針對其中兩個問題並將其列為最佳化問題，1) 在使用者傳輸量限制下最小化backhaul負擔，2) 在使用者傳輸量限制下最大化傳輸量總和。由此推得的解析解也經由Matlab的CVX來驗證相去無幾，並且能夠大幅降低運算量。模擬結果也驗證我們所提出的方案明顯降低了backhaul負擔且相較傳統方法在達成率上有著更好的效能。

We propose a mixed precoding strategy for CoMP systems, which allows that the orthogonal Block Diagonalization (BD) and the non-orthogonal Maximum Ratio Transmission (MRT) techniques can be simultaneously used for reducing network backhaul loading. We formulated the issues into two optimization problems. Namely, 1) minimizing the backhaul loading under a minimum target rate constraint and 2) maximizing the sum rate under a minimum target rate constraint. We derive closed-form solutions for these two problems and verify them by the Matlab CVX tool box. The de- rived closed-form solutions can signicantly reduce the computational time compared to the CVX. Simulation results show that the proposed precoding schemes can signicantly reduce the backhaul loading and outperform con- ventional schemes in terms of outage probability in achieving the minimum rate constraint.