臺灣大學: 電信工程學研究所蘇炫榮林秉勳Lin, Pin-HsunPin-HsunLin2013-03-272018-07-052013-03-272018-07-052010http://ntur.lib.ntu.edu.tw//handle/246246/253034在此論文第一部份中，我們考慮了在衰落通道下且傳輸端僅知部份通道資訊下的感知無線電設計。我們以較髒紙編碼更一般的葛爾分平斯克編碼，並考慮了快速以及緩慢衰落通道下的傳輸端設計。我們提出了半解析解以降低設計複雜度，同時提供了漸進分析來佐證此半解析解的正確性。數值模擬顯示我們提出的架構在衰落通道下且傳輸端僅知部份通道資訊下在目前已知文獻中表現最佳。我們並提出在高訊噪比下使用晶格編碼來實做此一系統。 在此論文第二部份中考慮一個較第一部份更為實際的問題：我們假設感知無線電接收端需要時間去解碼主要使用者的訊息。此外我們提出了利用接收端幫忙傳送，利用通道多樣性來提昇效能。由於此系統具有多重相位，為滿足感知無線電與主要使用者同時存在的條件，我們利用一般化漸進相同分割理論去分析此系統的效能。數值分析顯示此一系統能提供較前述系統更高的傳輸速率並具有較低的複雜度。The cognitive radio (CR) is a technology capable of dynamically sensing unused spectrum segments in a target spectrum pool, and communicating via the unused spectrum segments without causing harmful interference to the primary users. The main contribution of this thesis is about improving the CR performances in twofold. First, to accommodate the partial channel state information at the transmitter (CSIT) under Rician fading channels, we propose to use the linear-assignment Gel''fand-Pinsker coding (LA-GPC) to replace the dirty paper coding (DPC) in Jovacic-Viswanath (JV)''s CR model. This replacement can boost the performance of JV''s model. We also provide semi-analytical parameters design for the LA-GPC CR system. However, in Rayleigh fading channels, we find that the LA-GPC based CR cannot mitigate the interference as in Rician fading channels. Thus, our second main contribution is to propose the three-phase unidirectional transmitter cooperation CR and the three-phase unidirectional transmitter receiver cooperation CR. These two new CR models outperform the LA-GPC based and JV''s CR in Rayleigh fading channels. In the first part of the thesis, we present the design of cognitive radio in the Rician channel with partial CSIT. We replace the dirty paper coding used in JV''s model with full CSIT by the LA-GPC which can achieve better error performance when there is only partial CSIT. Based on the achievable rate derived from the LA-GPC, two optimization problems under the fast and slow fading channels are formulated. We derive semi-analytical solutions to find the relaying ratios and precoding coefficients. We also show that the parameters derived by the proposed methods converge to the optimal full CSIT solutions in the asymptotic cases. This result verifies the correctness of the proposed methods asymptotically. Moreover, a new coding scheme is proposed to implement the LA-GPC in practice. Simulation results show that the proposed semi-analytical solutions perform close to the optimal ones found by brute-force search, and outperform the systems based on naive DPC. Simulation results also show that the proposed practical coding scheme can effectively approach the theoretical rate performance. In Rayleigh fading channels , we derive that the performance of the LA-GPC based CR is the same as that of treating interference as noise. Thus in the second part of the thesis, we propose two new multi-phase CR transmission schemes by utilizing the relaying from the CR transmitter and receiver under the half-duplex constraints. And the receiver cooperation from the CR is the key to meet the coexistence constraint. Compared to the previous scheme, our multi-phase transmission protocols provide additional “clean” relaying paths without interference from the CR, which have additional diversity. The numerical examples show that the proposed schemes provide significant rate gains over previous scheme with less complexity penalties.824707 bytesapplication/pdfen-US感知無線電衰落通道葛爾分平斯克編碼髒紙編碼晶格編碼cognitive radioGelfand Pinsker codingdirty paper codinglattice codingthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/253034/1/ntu-99-F89921145-1.pdf