本文選題：無線通信 + 軌道角動量�。� 參考：《浙江大學》2017年碩士論文

【摘要】：隨著無線通信技術(shù)的快速發(fā)展,無線頻段的頻譜擁塞問題愈發(fā)嚴重,因此,在頻譜資源有限的情況下研究能夠提高頻譜利用效率的新型無線通信技術(shù)具有重要意義。研究表明,軌道角動量作為電磁場所攜帶的基本物理量之一,理論上擁有無窮多種本征模式,且不同本征模式之間具有正交性,如果能夠?qū)④壍澜莿恿康倪@一特性應(yīng)用于無線通信中,則有可能大幅提高現(xiàn)有無線通信的信道容量。本文以此為基礎(chǔ),對軌道角動量在未來無線通信中應(yīng)用的可行性、技術(shù)思路和方法進行相關(guān)研究,包括如何在射頻段生成攜帶軌道角動量的渦旋波束,渦旋波束的傳播特性分析,以及軌道角動量模式的檢測等問題;同時,本文基于渦旋波束所具有的獨特的空間相位特性,研究了將軌道角動量應(yīng)用于雷達目標檢測的可行性,相關(guān)研究內(nèi)容概括如下。本文提出了一種用于在射頻段生成渦旋波束的環(huán)形偶極子天線陣列。針對在實際的應(yīng)用場景中渦旋波束的生成問題,本文以天線設(shè)計領(lǐng)域中經(jīng)典的偶極子天線作為均勻環(huán)形天線陣列的陣元,對于偶極子在環(huán)形陣列中的四種排布方式,通過仿真分析發(fā)現(xiàn)只有平行偶極子環(huán)形陣列在線性相位激勵下才能生成攜帶軌道角動量的渦旋波束,在此基礎(chǔ)上,詳細研究了在該偶極子排布方式下環(huán)形陣列的各個參數(shù)對渦旋波束輻射特性的影響。同時基于環(huán)形天線陣列作為渦旋波束的接收端,仿真驗證了在該渦旋波束接收配置下軌道角動量模式間的正交性以及利用軌道角動量增加無線通信信道容量的可行性。本文提出了一種渦旋波束軌道角動量模式的偏軸檢測方法。針對傳統(tǒng)基于兩天線的相位梯度檢測法在檢測陣列相對于波束軸存在橫向偏移時檢測結(jié)果不再可靠的問題,提出一種基于均勻環(huán)形天線陣列的不需要確知波束軸位置即可檢測軌道角動量模式的檢測方法,仿真結(jié)果表明當檢測陣列相對于波束軸的橫向偏移量在給定范圍內(nèi)時,均可得到可靠的模式檢測結(jié)果,且檢測性能不受偏移量大小的影響。在此基礎(chǔ)上,針對波束軸偏移量更大的情形,本文又提出兩種適合低階軌道角動量模式偏軸檢測的網(wǎng)格天線陣列結(jié)構(gòu),相對于均勻環(huán)形陣列,這種網(wǎng)格陣列具有更大的空間覆蓋區(qū)域,且只要波束軸落入該陣列的覆蓋區(qū)域內(nèi),就能檢測出其軌道角動量模式,并能同時確定該波束軸所在的網(wǎng)格區(qū)域,這為后續(xù)收發(fā)陣列偏移校正等軌道角動量通信信號處理技術(shù)提供了有價值的參考。本文最后提出了一種基于渦旋電磁波的雷達目標二維成像方法�；谟删鶆颦h(huán)形天線陣列生成的渦旋電磁波投射下理想散射點的兩種回波模型,對雷達目標回波信號進行軌道角動量模式采樣并計算相關(guān)函數(shù),運用多重信號分類(MUSIC)算法得到空間譜函數(shù)并進行二維譜峰搜索從而實現(xiàn)對雷達目標俯仰角和方位角的二維聯(lián)合檢測,與現(xiàn)有的基于渦旋電磁波只能進行目標方位角成像的雷達成像方法相比,本方法能夠同時實現(xiàn)目標方位角和俯仰角的二維聯(lián)合成像,同時相對于傳統(tǒng)平面電磁波經(jīng)典的MUSIC二維成像算法,本方法能夠?qū)崿F(xiàn)更高的角度成像分辨率,且本方法在探測目標的過程中雷達不需要相對運動以及波束掃描,這對現(xiàn)代新型雷達系統(tǒng)的設(shè)計具有重要意義。
[Abstract]:With the rapid development of wireless communication technology, wireless frequency spectrum congestion problem is increasingly serious, therefore, research has important significance in improving the new wireless communication technology, the spectrum utilization efficiency in the case of limited spectrum resources. Studies show that one of the basic physics of orbital angular momentum as the electric magnetic field that carries the theory with an infinite number of the sign pattern has orthogonality between different intrinsic mode and, if the orbital angular momentum of the characteristics used in wireless communication, is likely to significantly improve the existing wireless communication channel capacity. Based on the orbital angular momentum in the feasibility of the application of wireless communication in the future, technology ideas and methods. The related research, including how to generate vortex beam with orbital angular momentum in the radio frequency range, the propagation characteristics of vortex beam, and the orbital angular momentum model The problem of detection; at the same time, the unique characteristics of the phase space is based on the vortex beam, the feasibility of the orbital angular momentum is applied in radar target detection, the related research contents are summarized as follows. This paper presents a circular dipole antenna array to generate vortex beam in the RF section for generating problem. Aiming at the vortex in the application the scene in the actual beam, based on the classical dipole antenna antenna design in the field as a uniform circular antenna array element, the four in the annular array arrangement of dipoles, the simulation results show that the vortex beam only parallel dipole circular array in linear phase excitation to generate carrying orbital angular momentum, on the basis of on the influence of radiation characteristic of vortex beam in various parameters of the dipole arrangement under the ring array are studied in detail. At the same time Circular antenna array based on vortex beam as the receiving end, simulation and verification of orthogonality in the vortex beam receiving configuration under orbital angular momentum between the modes and the feasibility of using orbital angular momentum to increase the channel capacity of wireless communication. This paper proposes a detection method of off-axis vortex beam orbital angular momentum mode. The traditional phase gradient detection the two method based on antenna array detection in detection results are no longer reliable with respect to the axis of the beam transverse offset problem, proposes a uniform circular antenna array does not need to know the position based on the axis of the beam can be detected orbital angular momentum model, the simulation results show that when the transverse offset detection array relative to the axis of the beam in a given range, can be model reliable test results, and the detection performance is not affected by the offset size. On this basis, according to the The axis of the beam offset is greater, this paper puts forward two kinds of grid antenna array structure for low order modes of the orbital angular momentum of off-axis detection, compared with the uniform circular array, the grid array has greater spatial coverage area, and as long as the axis of the beam into the array covering area, can detect the track the angular momentum model, and can also determine the grid area where the axis of the beam, which provides valuable reference for the subsequent receiving array offset correction of orbital angular momentum of communication signal processing technology. This paper finally puts forward a 2-D radar target imaging method based on electromagnetic vortex wave. Two echo model of ideal scattering points the electromagnetic wave generated vortex projection ring antenna array is composed of uniform based on radar echo signal of orbital angular momentum mode sampling and calculating the correlation function, the use of multiple signal classification (MUSIC) algorithm to obtain the spatial spectrum function and spectral peak searching so as to realize two-dimensional combined detection of radar target azimuth and pitching angle, compared with the existing radar imaging method of target azimuth imaging of vortex electromagnetic wave only based on this method can achieve planar imaging target azimuth and elevation angle. At the same time compared to the traditional algorithm of MUSIC imaging of plane electromagnetic wave classic, this method can achieve higher angle resolution, and this method in target detection in radar without relative motion and beam scanning, which is of important significance for modern radar system design.

【學位授予單位】：浙江大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TN957.52;TN92

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本文編號：1754095