| 摘要: | 隨著積體電路技術的發展演進，與傳統的半雙工中繼通訊相比，全雙工被認為是使中繼網路頻譜效率翻倍的潛在補救方案，因為只需要一次通道使用即可達成中繼通訊。然而使用全雙工於中繼節點不可避免地會造成自干擾問題，從而惡化系統端到端的效能，因此需要更多的研究來確認全雙工的可行性。另外，通過無線充電為低功耗無線中繼裝置提供方便且永久的能源在物聯網時代更是至關重要。應用能量獵取的一個主要問題是由於中繼節點的資源有限會造成無線能量獵取和訊息傳輸之間存在效能折衷。本計畫的研究目標是通過研究具有或不具有可無線充電的全雙工中繼網絡來解決這些挑戰，其中吾人一併考慮放大轉發和選擇性解碼轉發中繼傳輸協定。在此研究計畫中，不是簡單地將自干擾視為雜訊，吾人試圖有效地利用網絡中的自干擾訊號來促進訊號解碼和能量獵取。對於全雙工放大轉發中繼網絡，我們充分利用接收節點自干擾訊號中嵌入的資料訊息來協助訊息解碼，從理論上分析通道容量中斷概率效能。然後從理論上重新回顧與分析使用獲取的能量充當中繼節點發射功率的全雙工無線充電放大轉發中繼網絡的效能，其中在中繼節點進一步應用具有可調比例的功率分配器，以將接收到的訊號分成兩個部分用於訊號解碼和能量獵取目的。對於全雙工選擇性解碼轉發中繼網絡，吾人通過研究自干擾訊號對符元錯誤率的影響來理論分析系統效能。接續從理論上分析可充電的全雙工選擇性解碼轉發中繼網路的符元錯誤率和通道容量中斷概率效能。藉由上述理論效能分析，吾人通過最小化通道容量中斷概率或符元錯誤率來最佳化系統參數，例如節點發射功率、功率分配器比例和中繼節點部署。最後透過電腦模擬來驗證所提出方法的有效性並且顯示系統效能。 ;With the evolution of integrated circuit (IC) techniques, full-duplex has been considered as a potential remedy to double the spectrum efficiency of relay networks as only one channel is needed per two hops, as compared with the conventional half-duplex relays. However, the inclusion of the full-duplex feature at relays inevitably suffers from a self-interference problem, thereby deteriorating the end-to-end system performance, and it solicits more studies to render full-duplex feasible. In addition, it is critical to provide convenient and perpetual energy to low-powered wireless relays via wirelessly charging, especially in the era of Internet of Things (IoT). A major concern for applying energy harvesting is that there exists a performance tradeoff between wireless energy and information transfer due to the limited resource at the relays. The goal of this project is to address these challenges by investigating full-duplex relay networks with or without rechargeable wireless relays, in which amplify-and-forward (AF) and selective decode-and-forward (SDF) transmission protocols are both taken into consideration. Instead of simply treating the self-interference as noise, we attempt to effectively utilize the self-interference in the network to facilitate both signal decoding and energy harvesting. For the full-duplex AF relay network, we theoretically analyze the capacity outage performance by fully exploiting the data information embedded in the self-interference at the destination node. We then theoretically revisit the performance of the full-duplex rechargeable AF relay network with the harvested energy served as relay transmit power, where a power splitter with an adjustable ratio is further applied at the relay to divide the received signal into two portions for signal decoding and energy harvesting purposes. For the full-duplex SDF relay network, we theoretically analyze the performance by capturing the impact of the self-interference on the symbol error rate. As an extension, we theoretically analyze the symbol error rate and capacity outage performance with the rechargeable relay. With the theoretical analyses, we jointly optimize the system parameters, e.g., transmit power, power splitter ratio, and relay deployment, by minimizing the capacity outage or symbol error rate. Finally, computer simulation will be conducted to verify the effectiveness of the proposed schemes and to show the system performance. |
