具中繼點審核機制之合作式同時 無線訊息與能量傳輸

Abstract

在本論文中，我們探討了在接收端點可以進行同時無線訊息與能量傳輸的結合中繼點審核機制與能量獲取的合作式通訊系統設計。我們考慮了功率分配的方法來達成同時無線訊息與能量傳輸。在能量獲取的觀點來說，我們希望增加能量獲取的機會，所以在中繼點審核機制的訊雜比臨界值希望能夠設得低一些來保持中繼點運作的機會；然而，在訊息解碼的觀點來說，低訊雜比臨界值會使端點到端點的位元錯誤率變差，而且如果在接收端進行同時無線訊息與能量傳輸的功率分配，其接收訊號拿去做能量獲取的功率比例幾乎等於一時，代表接收訊號沒有多餘的功率拿去做訊息解碼，如此也會造成端點到端點的位元錯誤率變差。因此，在本篇論文中，我們提出了三種方式來制定問題使得系統錯誤機率與獲取能量之間的性能可以達到平衡的表現，並且提出演算法來去推導出中繼點審核機制之訊雜比臨界值與接收端點同時無線訊息與能量傳輸之功率分配比例的最佳解。

In this thesis, we consider a joint relay censoring and energy harvesting cooperative communication system, where the destination can simultaneously harvest energy and decode information from the received signal sent by the relay. We consider power splitting scheme at the destination to achieve SWIPT. On the energy harvesting side, we aim at increasing the harvested energy as much as possible, so the SNR threshold at the relay censoring may be low to keep the relay active most of the time, so that the power level to energy harvesting can be high. But, low SNR threshold may deteriorate the e2e bit error rate (BER) of the system on the information decoding side. And if the proportion of the received power split to energy harvesting is almost equal to 1, there is almost no power used for information decoding, which leads to bad e2e BER performance as well. In our work, we study three methods to formulate the joint problem to balance the performances between the system’s error probability and harvested energy and propose algorithms to derive the optimal solutions of the SNR threshold at the relay censoring and the power splitting ratio at the destination.