廣播通道之編碼技術與功率分配

Abstract

一個傳送端同時傳送訊息給多個使用者的情況被稱為廣播通道。在本篇論文中，我 們研究多使用者且多重輸入單一輸出廣播通道之編碼技術與功率分配。首先，從消息 理論的角度，我們介紹髒紙編碼和用TCQ/TCM 來實現髒紙碼。再來我們把TCQ/TCM 運用到多重輸入單一輸出廣播通道上。這種傳輸方式是基於連續髒紙編碼技術以及功 率分配在每一個使用者有傳送速率的限制下。在有傳送速率的限制情況下，最佳化問 題的目標是要最小化傳輸功率。而計算會藉由廣播通道與多重存取通道的對偶性質。 接下來，在固定的通道狀況下，我們模擬TCQ/TCM 在有兩個使用者的多重輸入單一 輸出和單一輸入單一輸出廣播通道下的情況。此外，考慮緩慢衰減通道也被考慮到。 我們讓中斷機率作為效能的測度以及在有個別傳輸速率和總和傳輸速率的限制下模擬 我們的傳輸方法。從模擬結果來看，有著總和傳輸速率限制的傳輸方法會有比較好的 分集。 ii

A broadcast channel is the scenario where a transmitter sends the message to multiple users simultaneously. In this thesis, a coding scheme with power allocation for the MISO broadcast channel with multiple users is investigated. First, the information theory for the dirty paper coding (DPC) is studied and the TCQ/TCM is used for the implementation of DPC. Then, the TCQ/ TCM is applied to MISO broadcast channels. The transmission scheme is based on successive dirty paper coding and power allocation subject to rate constraints for each user. Under the rate constraints, the optimization objective is to minimize the transmitted power, using the duality between broadcast channels and multiple access channels. Next, we simulate the TCQ/TCM for the SISO and MISO broadcast channels with a fixed channel state and two users. In addition, the slow fading channel is considered. We let the outage probability be the performance measure and simulate our transmission scheme under the individual rate constraints and sum-rate constraint, respectively. From the simulation results, it can be seen that the transmission scheme under the sum-rate constraint has better diversity.