單一及多個的多天線中繼器的合作式網路使用動態解碼後傳送協定之分集與多工增益權衡效能的設計與分析

Abstract

考慮一個合作式網路含有一個傳送端，一個接收端以及中繼器並使用動態解碼後傳送(DDF)的通訊協定，且各個端點都擁有多天線。在目前已存在的動態解碼後傳送協定中，它會遭受到一個無限長延遲，這是完全不合實際的。除此之外，多個擁有多天線的中繼器的分析還未被實行。在本篇論文中，我們會先討論單一個多天線中繼器的動態解碼後傳送協定並在有限的延遲條件下，他們各自的分級與多工增益權衡效能。我們發現即使是在短延遲的條件下，該協定依然擁有合理且還不錯的分級與多工增益權衡效能。接下來我們主要討論及觀察當擁有兩個多天線中繼器的動態解碼後傳送協定，他們各自的分級與多工增益權衡效能。並且讓它與在中繼器端擁有相同天線數量的單一個中繼器做比較。之後我們能結論出一些結果，在上述的大多數的天線組合結構中，他們擁有不同的分級與多工增益權衡效能，此外，我們發現相同的天線數量，但不同的分配在第一個中繼器和第二個中繼器，會影響對分級與多工增益權衡效能。

Consider a cooperative network consisting of a source node, a destination node and some relay nodes, each having multiple antennas and employing a dynamic decode-and-forward (DDF) communication protocol. The existing DDF protocol suffers from an infinitely long delay and is completely impractical, and the diversity performance for MIMO relay network with multiple relays remains unknown to this date. In this thesis, we first investigate the performance of a finite-delay DDF protocol operating on MIMO relay channel with single relay using the diversity-multiplexing gain tradeoff (DMT) as a performance measure. It is seen that the finite-delay DDF can have a reasonably good DMT performance even in case of a short delay. Next, we focus on the DMT of the DDF protocol for two relays with multiple antennas and compare it with the single relay case having the same overall amount of antennas. It is surprisingly seen that for mostly channel configurations described above, the two settings can result in different diversity performance. It is also found in this thesis that the distribution of antennas between two relays affects the overall DMT performance.