頻譜分享認知無線電網路之允入與功率控制

Admission and Power Control for Spectrum Sharing Cognitive Radio Networks

謝冠宇(Guan-Yu Sie)

指導教授 ： 王瑞騰

國立暨南國際大學/科技學院/電機工程學系/碩士(2015年)

摘要

我們研究允入與功率控制的問題在認知無線電網路情況下。在主要使用者(許可用戶)與次要使用者(未經許可用戶)同時傳輸並使用相同的頻寬。

在認知無線電網路下，主要使用者分享相同的接收者，在這個接收者下的次要使用者的干擾等級應該要有嚴厲的限制條件，這樣能讓主要使用者可以維持服務品質。在允入下，每個次要連結假設要有最低的QoS要求，並且都要有干擾的限制條件，否則次要連結不能允入。

在上述限制下，研究允入與功率控制對次使用者兩個優化目標，第一個我們管理允入次要連結的最大數量。第二個我們管理允入次要連結的最大吞吐量。第一個問題是NP-hard，因此我們研究一個分散式的解去接近最佳化的解，基於這個測量法，每個使用者需要限制信號量。目標函數為實現第二個優化目標是非凸的，因此我們研究次優演算法，建立在連續幾何的設計。

關鍵字

認知無線電 ； 允入與功率控制 ； 凸優化

並列摘要

We investigate the problem of admission and power control for cognitive radio (CR) networks, where the primary users (licensed users) and the secondary users (unlicensed users) are transmitting concurrently over the same band. In the considered CR networks, the primary users share a common receiver, and the interference on this receiver from the secondary users should be strictly limited to a certain level so that the quality of service (QoS) of the primary users can be maintained. In addition, each secondary link is assumed to have a minimum QoS requirement that should be satisfied together with the interference limit constraint, otherwise the secondary link is not admitted. Under the above constraints, admission and power control for the secondary users are investigated to attain the following two main optimization objectives. First, we manage to maximize the number of the admitted secondary links. Second, we manage to maximize the sum throughput of the admitted secondary links. The problem for attaining the first optimization objective is NP-hard, hence we study a distributed close-to-optimal solution based on local measurements at each user and a limited amount of signaling. The objective function for attaining the second optimization objective is non-convex, thus we study a suboptimal algorithm based on sequential geometric programming.

並列關鍵字

Cognitive radios ； admission and power control ； convex optimization

參考文獻

[1]FCC, Spectrum policy task force report, FCC 02-155, Nov. 2002.

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