本文選題：頻譜共享 + 頻譜感知�。� 參考：《北京交通大學(xué)》2017年博士論文

【摘要】：近幾十年,無線通信技術(shù)得到飛速發(fā)展,各種新技術(shù)和新業(yè)務(wù)不斷涌現(xiàn),以滿足人們對更高速優(yōu)質(zhì)通信體驗的需求。然而,隨著適宜通信的頻段被分配殆盡,頻譜資源成為制約無線通信技術(shù)演進(jìn)的主要瓶頸之一,頻譜共享技術(shù)作為解決這些問題的重要途徑日益受到人們的重視。傳統(tǒng)的頻譜共享技術(shù)主要圍繞認(rèn)知無線電場景展開,在第5代移動通信技術(shù)和物聯(lián)網(wǎng)技術(shù)快速發(fā)展的今天,頻譜共享技術(shù)又被賦予了新的含義,得到了更為廣泛的應(yīng)用,如環(huán)境反向散射通信和高速鐵路移動通信等。頻譜共享的核心思想是在同一空間內(nèi),兩個及以上的無線通信系統(tǒng)共同利用同一段頻譜分別進(jìn)行通信以提高頻譜的有效利用率。在這種多個主體共存的空間中,主體之間的相互干擾、共同利用空間中資源時產(chǎn)生的沖突在所難免。那么如何合理地設(shè)計系統(tǒng)使得系統(tǒng)中各主體之間能夠和諧共處、高效有序的利用資源就具有重要意義。其中的一項關(guān)鍵要素就是對空間中其他主體行為的感知。對應(yīng)于頻譜共享系統(tǒng),設(shè)計有效的檢測算法以感知各通信系統(tǒng)對頻譜的占用情況就成為舉足輕重的一個課題,同時,精確的檢測算法又能夠優(yōu)化整個頻譜共享系統(tǒng)的通信效率,提高系統(tǒng)的吞吐量。本論文圍繞著基于頻譜共享的無線通信系統(tǒng)的檢測算法及其對系統(tǒng)性能的影響展開研究,針對基于認(rèn)知通信的頻譜共享網(wǎng)絡(luò),提出多種適用于不同場景的頻譜感知算法,分析了頻譜感知對系統(tǒng)容量性能的影響,探究了高速移動場景下頻譜共享用戶的遍歷容量性能,最后研究了基于環(huán)境反向散射的頻譜共享網(wǎng)絡(luò)中存在的次用戶信號檢測問題。論文的創(chuàng)新性工作主要包括如下幾個方面:(1)傳統(tǒng)的頻譜感知算法通常只能分辨主用戶是否工作兩種狀態(tài),隨著通信技術(shù)的發(fā)展,越來越多的授權(quán)頻段用戶發(fā)射機(jī)具備功率控制功能,可以實現(xiàn)在多個發(fā)射功率之間切換,本文設(shè)計一種基于協(xié)作用戶信息軟合并的頻譜感知算法,在感知主用戶是否工作的同時,可以檢測得到主用戶所使用的發(fā)射功率,并應(yīng)用此信息對次用戶的吞吐量進(jìn)行優(yōu)化。此外還針對該場景的特殊性,分析了次用戶對主用戶所使用發(fā)射功率分辨能力對系統(tǒng)吞吐量的影響,研究發(fā)現(xiàn)次用戶并不需要檢測出全部的主用戶發(fā)射功率就可以實現(xiàn)與全部檢測相近的吞吐量性能,這一發(fā)現(xiàn)有助于系統(tǒng)的優(yōu)化設(shè)計;(2)針對基于能量檢測的頻譜感知算法在低信噪比場景下檢測精度受限的問題,設(shè)計了一種基于信號循環(huán)平穩(wěn)特性的協(xié)作檢測算法,對噪聲的概率密度分布沒有特定假設(shè)的要求,具有更好的普適性;同時針對傳統(tǒng)循環(huán)平穩(wěn)檢測需要預(yù)知主用戶信號循環(huán)頻率的問題,利用參與協(xié)作的各個次用戶接收到的信號構(gòu)建具備循環(huán)平穩(wěn)特征的檢測樣本,有效解決了這一問題;(3)以高速鐵路移動通信為背景,引入車頂中繼天線,實現(xiàn)車內(nèi)用戶與路面基站的通信,建立了相應(yīng)的時變頻選信道中繼通信系統(tǒng)模型,研究當(dāng)車廂內(nèi)用戶以頻譜共享方式接入車廂內(nèi)熱點后所能獲得的信道遍歷容量,推導(dǎo)得到了容量上界和下界的閉合表達(dá)式,同時得到了高信噪比下近似結(jié)果的閉合表達(dá)式。隨著高速鐵路的快速發(fā)展,高速移動場景下的通信問題受到學(xué)術(shù)界的日益重視,所得到的理論結(jié)果補(bǔ)充了目前在高速移動場景下時變頻選中繼信道遍歷容量分析方面研究的不足,可以為構(gòu)建車內(nèi)頻譜共享網(wǎng)絡(luò)提供上層決策和資源管理方面的性能參考;(4)研究了基于環(huán)境反向散射通信技術(shù)的頻譜共享網(wǎng)絡(luò),當(dāng)標(biāo)簽可以實現(xiàn)兩種對環(huán)境信號的處理狀態(tài)時,利用差分編碼降低檢測對信道狀態(tài)信息的依賴,設(shè)計了一種基于中心極限定理的能量檢測算法;當(dāng)標(biāo)簽可以實現(xiàn)三種不同狀態(tài)時,提出了一種可以使誤碼率最小的三進(jìn)制編碼策略,并設(shè)計了相應(yīng)的檢測器,分析并推導(dǎo)了其誤碼性能的閉合表達(dá)式,證明了其在高信噪比區(qū)域存在地板效應(yīng)。最后通過仿真驗證了當(dāng)標(biāo)簽具有三種狀態(tài)時能有效改善環(huán)境反向散射通信系統(tǒng)速率受限的問題。
[Abstract]:In recent decades, wireless communication technology has developed rapidly and new technologies and new services are emerging to meet the needs of high speed and high quality communication experience. However, as the frequency of appropriate communication is distributed, spectrum resources become one of the main bottlenecks that restrict the evolution of wireless communication technology. Spectrum sharing technology is the solution to this The important ways of some problems are becoming more and more important. The traditional spectrum sharing technology is mainly around the cognitive radio scene. In the fifth generation of mobile communication technology and the rapid development of the Internet of things technology, the spectrum sharing technology has been given new meanings, and has been more widely used, such as environment backscatter communication and high The core idea of the speed railway mobile communication. The core idea of the spectrum sharing is that in the same space, two or more wireless communication systems communicate with the same spectrum to improve the effective utilization of the spectrum. In this space, the mutual interference between the main bodies is used to make use of the resources in the space. It is unavoidable that it is inevitable that how to design a system reasonably so that each subject in the system can coexist harmoniously and efficiently and orderly use of resources. One of the key elements is the perception of the behavior of other subjects in the space. Corresponding to the spectrum sharing system, an effective detection algorithm is set up to perceive communication systems. At the same time, the accurate detection algorithm can optimize the communication efficiency of the whole spectrum sharing system and improve the system throughput. This paper focuses on the detection algorithm of the wireless communication system based on the spectrum sharing and its influence on the system performance. In the spectrum sharing network of knowledge communication, a variety of spectrum sensing algorithms suitable for different scenes are proposed. The influence of spectrum sensing on the capacity performance of the system is analyzed. The traversal capacity performance of the spectrum sharing users in the high-speed mobile scene is explored. Finally, the sub user signal detection in the spectrum sharing network based on the environment backscatter is studied. The innovative work of this paper mainly includes the following aspects: (1) the traditional spectrum sensing algorithm usually can only distinguish whether the main user works two kinds of state. With the development of communication technology, more and more authorized frequency band transmitter has power control function and can be switched between multiple transmit power. A spectrum sensing algorithm based on cooperative user information is proposed, which can detect the transmission power used by the main user while perceiving whether the main user is working, and uses this information to optimize the throughput of the secondary users. In addition, the transmission power used by the secondary users to the main user is also analyzed. The effect of resolution on the throughput of the system is found. It is found that the secondary user does not need to detect all the main user transmission power to achieve the throughput performance similar to all detection. This discovery is helpful to the optimization of the system. (2) the detection precision of the frequency spectrum sensing algorithm based on the energy detection is affected by the low signal to noise ratio scene. A cooperative detection algorithm based on the cyclostationary characteristic of the signal is designed. The probability density distribution of the noise has no specific hypothesis, and it has a better universality. At the same time, the traditional cyclic stationary detection needs to predict the circulation frequency of the main user signal, and use the letters received by the various sub users involved in the cooperation. In order to solve this problem effectively, this problem is solved effectively. (3) taking the mobile communication of high speed railway as the background, introducing the roof relay antenna to realize the communication between the user and the base station of the base station, the corresponding time frequency channel relay communication system model is set up, and the users in the compartment are connected in the way of sharing the frequency spectrum. The capacity of the channel traversal after the hot spot in the car is obtained, and the closed expression of the upper and lower bounds of the capacity is derived. At the same time, the closed expression of the approximate results under the high signal to noise ratio is obtained. With the rapid development of the high-speed railway, the communication problem in the high-speed moving scene is paid more and more attention by the academic circles, and the theoretical results are supplemented. The shortcomings of the research on the traversal capacity analysis of the time-frequency selective relay channel in high-speed mobile scene can provide the performance reference for the upper decision and resource management for the building of the intra spectrum sharing network. (4) the frequency spectrum sharing network based on the environment backscatter communication technology is studied. When the label can implement two kinds of environment In the processing state of the signal, using the differential coding to reduce the dependence on the channel state information, a new energy detection algorithm based on the central limit theorem is designed. When the label can realize three different states, a three binary coding strategy which can minimize the bit error rate is proposed, and the corresponding detector is designed and analyzed and pushed. The closed expression of the error code performance is derived, which proves that there is a floor effect in the high signal to noise ratio region. Finally, the problem of improving the rate limitation of the environment backscatter communication system can be effectively improved when the label has three states.
【學(xué)位授予單位】：北京交通大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TN92

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本文編號：1900191