在無線通訊中，合作式通訊技術可以經由中繼端轉送彼此訊息至目的端而形成一個分散式天線陣列，進而提供空間分集增益。
在有限的功率資源限制下，為了維持各種無線通訊系統的服務品質需求，功率資源分配為一個重要的考量；允入控制機制將系統中的所有使用者的鏈結做控管動作，配合適當的功率配置將可有效降低網路壅塞及連結中斷的情形發生。此外，基於各傳輸路徑的通道狀態，藉由選擇適宜的中繼端協助使用者傳輸訊息，能使系統更容易滿足使用者之服務品質需求及達到效能提昇之目的。
本論文中，對於放大傳遞中繼網路，首先我們提出以簡易且有效率的混合式基因演算法來同時實行允入控制及功率分配，在有限的合作式通訊系統功率資源下允入最多的使用者，並讓使用者能確保一個最小的服務品質，並同時於使用者及中繼端之間實行最佳化功率分配，使得整體使用者的傳輸功率消耗最小化；接著我們將對此混合式基因演算法做延伸，在結合允入控制及功率分配中加入中繼端選擇機制，加入此機制將可得到系統效能進一步提昇的優點。
在第二部份中我們考慮在雙向多天線合作式放大傳遞網路中，結合中繼端選擇及使用者端與中繼端之間的功率分配，在一個系統總功率限制條件下，最大化系統總傳輸速率，對此複雜的非線性問題我們亦提出了新型的混合式基因演算法來求解；之後我們於新型的混合式基因演算法中加入天線選擇部分，選取傳輸速率較高的天線傳送資料，以進一步提昇系統效能。
相關的模擬結果顯示我們提出的方法相較前人提出的方法，可以獲得更好的系統效能，並且大量、有效地降低運算複雜度。

In wireless networks, cooperative communications are an emerging transmission technique in which a distributed antenna array can be created and provided the spatial diversity gains by relaying each other's messages to the destination. Under limited resource, to support various integrated services with a prescribed quality of service (QoS) requirement, resource provisioning is a important issue. Admission control with resource allocation is such a provisioning strategy which limits the number of call connections into the networks in order to reduce the network congestion and call dropping. Also, relay selection, which selects an appropriate set of relays based on cahnnel state information (CSI) at the relay nodes or at the destination nodes, is yet another technique to enhance the system performance.
In this thesis, we first propose a simple and efficient hybrid genetic algorithm (HGA) approach for simultaneously implementing the admission control and the power allocation away the source nodes and the relay nodes, aiming at maximizing the number of users served and minimizing the transmit power in the resource-limited amplify-and-forward (AF) cooperative systems. We also combine the above joint problem with the relay seleced technique to improve the system problem.%It is advantageous to combine the relay selection scheme to further enhance the system performance.
In the second part of the thesis we consider a joint relay selection and power allocation among the user and the relays in two-way AF MIMO cooperative power-limited systems based on the sum rate maximization criterion. To alleviate the computational load, we also employ a new HGA to resolve the highly nonlinear optimization involved. The antenna selection on both of the user nodes, which selects the optimal antenna subset, is also incorporated to further enhance the system performance.
\par Furnished simulations show that the proposed new GA approaches indeed yield superior performance with reduced computational complexity overhead compared with previous works in various scenarios.
Keywords: cooperative communications, amplify-and-forward, genetic algorithm, admission control, power allocation, antenna selection.

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