湯亞鴿 楊明 金強(qiáng)
摘? 要:近年來,非均勻線性陣列引起了陣列信號(hào)處理領(lǐng)域研究者的廣泛關(guān)注。在陣型設(shè)計(jì)中的一個(gè)關(guān)鍵的問題是,設(shè)定傳感器放置位置以獲得最大自由度和最小互耦效應(yīng)。文章將嵌套陣列的密集子陣分成若干部分,然后將這些部分重新排列在嵌套陣列的兩側(cè),由此提出了增強(qiáng)嵌套陣列的概念,并且給出了物理陣元位置的四種典型形式,同時(shí)針對任意給定的陣元數(shù)推導(dǎo)出虛擬傳感器的位置。與具有相同陣元數(shù)的嵌套陣列相比,文章所提曾廣嵌套陣列具有更高的自由度和更小的互耦效應(yīng)。最后,仿真實(shí)驗(yàn)驗(yàn)證了所提出增強(qiáng)嵌套陣列的有效性。
關(guān)鍵詞:增強(qiáng)嵌套陣列;自由度;互耦效應(yīng);DOA估計(jì);稀疏線性陣列
中圖分類號(hào):TN911.7 文獻(xiàn)標(biāo)志碼:A 文章編號(hào):2095-2945(2019)24-0101-02
Abstract: In recent years, non-uniform linear array has attracted wide attention of researchers in the field of array signal processing. One of the key problems in formation design is to set the position of the sensor to obtain the maximum degree of freedom and the minimum mutual coupling effect. In this paper, the dense subarray of a nested array is divided into several parts, and then these parts are rearranged on both sides of the nested array. Based on this, the concept of enhanced nested array is proposed, and four typical forms of physical array element positions are given. At the same time, the position of the virtual sensor is deduced for any given number of array elements. Compared with the nested array with the same number of elements, theenhanced nested array proposed in this paper has higher degrees of freedom and smaller mutual coupling effect. Finally, simulation experiments verify the effectiveness of the proposed enhanced nested array.
Keywords: enhanced nested array; degree of freedom; mutual coupling effect; DOA estimation; sparse linear array
1 概述
陣列信號(hào)處理在許多領(lǐng)域具有關(guān)鍵作用,比如雷達(dá)、通信、導(dǎo)航等[1]。目前大部分研究人員主要關(guān)注均勻線陣(ULA),其相鄰傳感器間的陣元間距小于λ/2。對于均勻線陣來說,孔徑的增加通常會(huì)增加硬件成本和計(jì)算復(fù)雜度。在獲得最大的空間分辨率、自由度和最小的互耦效應(yīng)方面,非均勻線陣(NLA)比均勻線陣更受關(guān)注,代表陣型為最小冗余陣列(MRAs)[2]或最小孔陣列(MHAs)[3]。近年來,關(guān)于嵌套陣列[4]和互質(zhì)陣列[5]的研究重新引起了人們對NLA的關(guān)注。然而,NLA也存在局限性。MRA/MHA/NMRA閉式表達(dá)式,只有通過窮盡搜索出來的結(jié)果。嵌套陣列中包含密集的ULA,這都會(huì)引起高互耦效應(yīng)。
本文提出了一種高自由度低復(fù)雜度的增強(qiáng)嵌套陣設(shè)計(jì)方法,該方法利用增強(qiáng)嵌套陣列(ANA)的概念,將子陣重新排列在嵌套陣列的兩側(cè)。同時(shí),還創(chuàng)造性的給出了保證虛擬陣列無孔的空間物理陣型結(jié)構(gòu)。理論分析結(jié)果顯示,構(gòu)造的ANA具有以下優(yōu)點(diǎn):(1)ANA具有閉式物理陣元位置和無孔的虛擬陣列模型。(2)在陣元數(shù)量相同的條件下,相比于互質(zhì)陣列和嵌套陣列,ANA具有更高的陣列自由度。(3)相比于嵌套陣列和超級(jí)嵌套陣列的前幾級(jí),ANA的互耦度更低。
2 差分集合模型
5 結(jié)論
為了同時(shí)獲得高陣列自由度和低互耦效應(yīng),本文提出了一種新的增強(qiáng)嵌套的稀疏NLA,該陣型保證了新形成的ANA是無孔的。結(jié)果表明,對于任何給定的陣元數(shù),均可生成優(yōu)良的稀疏陣列。仿真實(shí)驗(yàn)證明,與具有相同物理陣元數(shù)量的嵌套陣列相比,ANA可在不同的層面獲得更高的陣列DOF。最后,仿真結(jié)果驗(yàn)證了所提出陣列流型的有效性。
參考文獻(xiàn):
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