發(fā)布時間：2018-06-13 13:35

  本文選題：無線通信 + 協(xié)作分集��； 參考：《北京交通大學》2014年碩士論文

【摘要】：目前,協(xié)作中繼技術(shù)在無線通信領(lǐng)域是一個前沿的研究方向,它可以克服MIMO (Multiple-Input Multiple-Output)技術(shù)因受制于體積及功率等條件限制而無法應(yīng)用于實際無線終端中的難題。其基本思想是配置單天線的多個用戶通過共享彼此的天線,從而形成虛擬的MIMO系統(tǒng)。協(xié)作中繼技術(shù)可以有效地降低無線信道中的衰落特性以及鏈路不穩(wěn)定性造成的影響,提高無線通信系統(tǒng)的頻譜效率以及數(shù)據(jù)傳輸速率。 本文對無線單向中繼系統(tǒng)中的中繼伙伴選擇方案和雙向中繼系統(tǒng)中的中繼伙伴選擇方案這兩種目前協(xié)作通信的研究方向進行了研究,本文的主要研究內(nèi)容和創(chuàng)新點如下： 1.在研究無線單向中繼系統(tǒng)中的協(xié)作中繼選擇方案中,針對放大轉(zhuǎn)發(fā)模式下的單向中繼協(xié)作系統(tǒng),結(jié)合已有的協(xié)作中繼模型,重點探討了移動中繼節(jié)點選擇的相關(guān)內(nèi)容,提出了一種動態(tài)中繼選擇策略。在提出的中繼選擇策略中,假設(shè)無線協(xié)作系統(tǒng)的總功率固定,并且節(jié)點之間的鏈路信道狀態(tài)信息(Channel State Information)可獲知,當用戶進入路邊AP(Access Point)的覆蓋范圍時,通過將各中繼的狀態(tài)值與設(shè)定的最小閾值進行比較來剔除多余中繼節(jié)點。此外,針對中繼系統(tǒng)的功率資源問題,分析了帶寬歸一化系統(tǒng)容量、系統(tǒng)信噪比以及用戶的發(fā)射功率因子之間的關(guān)系。通過模擬實際高速公路場景建模,對提出的相關(guān)算法進行仿真實驗,結(jié)果驗證了本文提出的動態(tài)中繼選擇策略能夠有效地降低系統(tǒng)的中斷概率,同時還能保持系統(tǒng)容量基本不變。 2.在研究無線雙向中繼系統(tǒng)中的協(xié)作伙伴選擇方案中,通過對目前的雙向中繼選擇研究進展進行歸納總結(jié),基于現(xiàn)有的雙向中繼選擇算法,改進了一種雙向中繼選擇算法。本文還對雙向中繼系統(tǒng)中的功率資源分配問題進行研究,通過對相關(guān)文獻的查閱,改進了一種基于加權(quán)總速率最大化的功率分配策略。經(jīng)過合理的仿真設(shè)置,對改進的雙向中繼算法及功率分配策略都進行了多次仿真實驗。通過與現(xiàn)有的雙向中繼選擇算法比較,結(jié)果顯示改進后的雙向中繼選擇算法可以在一定情況下獲得更突出的性能表現(xiàn),此外,通過與現(xiàn)有功率分配策略比較,結(jié)果顯示本文提出的功率分配策略在一定情況下能夠提高系統(tǒng)傳輸總速率。
[Abstract]:At present, cooperative relay technology is a frontier research field in wireless communication field. It can overcome the problem that MIMO Multiple-Input Multiple-Output technology can not be applied to practical wireless terminals because of the constraints of volume and power. The basic idea is to form a virtual MIMO system by sharing each other's antennas with multiple users with a single antenna. Cooperative relay technology can effectively reduce the fading characteristics in wireless channels and the impact of link instability, and improve the spectral efficiency and data transmission rate of wireless communication systems. In this paper, two kinds of cooperative communication research directions, relay partner selection scheme in wireless one-way relay system and relay partner selection scheme in two-way relay system, are studied. The main contents and innovations of this paper are as follows: 1. In the research of cooperative relay selection scheme in wireless unidirectional relay system, aiming at the one-way relay cooperation system in the mode of amplification and forwarding, combined with the existing cooperative relay model, this paper focuses on the selection of mobile relay nodes. A dynamic relay selection strategy is proposed. In the proposed relay selection strategy, it is assumed that the total power of the wireless collaboration system is fixed and that the link channel state information between nodes can be obtained when the user enters the coverage of the roadside APN access point, Redundant relay nodes are eliminated by comparing the state values of each relay with the set minimum threshold. In addition, aiming at the power resource problem of relay system, the relationship between bandwidth normalized system capacity, system SNR and user transmit power factor is analyzed. By simulating the actual freeway scene modeling and simulating the related algorithms, the results show that the proposed dynamic relay selection strategy can effectively reduce the outage probability of the system. At the same time can also maintain the system capacity is basically unchanged. 2. In the research of cooperative partner selection scheme in wireless bidirectional relay system, a bidirectional relay selection algorithm is improved based on the existing bidirectional relay selection algorithm by summarizing the current research progress of bidirectional relay selection. In this paper, the power resource allocation problem in bidirectional relay system is studied, and a power allocation strategy based on weighted total rate maximization is improved by consulting related literatures. After reasonable simulation, the improved bidirectional relay algorithm and power allocation strategy are simulated many times. By comparing with the existing bidirectional relay selection algorithm, the results show that the improved bidirectional relay selection algorithm can obtain more outstanding performance under certain circumstances, in addition, by comparing with the existing power allocation strategy, The results show that the proposed power allocation strategy can improve the total transmission rate under certain conditions.
【學位授予單位】：北京交通大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN92

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本文編號：2014193