本文選題：多小區(qū)　切入點(diǎn)：多天線　出處：《西安電子科技大學(xué)》2014年碩士論文

【摘要】：近年來(lái),隨著多媒體業(yè)務(wù)和移動(dòng)智能終端的不斷發(fā)展,無(wú)線通信數(shù)據(jù)量激增。為了滿足人們對(duì)于更高數(shù)據(jù)速率的需求,各種提高頻譜利用率的技術(shù)得到了巨大發(fā)展。其中多輸入多輸出(MIMO,Multiple-Input Multiple-Output)技術(shù)由于其能夠有效利用空間復(fù)用增益來(lái)提高系統(tǒng)的傳輸速率而受到了越來(lái)越多的關(guān)注。同時(shí),為了提高頻譜的利用率,普遍采用復(fù)用因子為1的方式進(jìn)行組網(wǎng)。這樣在小區(qū)的邊緣用戶就會(huì)不可避免地收到來(lái)自其它基站的干擾以及多天線之間的干擾,干擾問(wèn)題成為了限制系統(tǒng)容量的主要因素。干擾對(duì)齊(IA,Interference Alignment)作為干擾協(xié)作的一種特殊形式成為了目前的研究熱點(diǎn)之一。干擾對(duì)齊打破了傳統(tǒng)MIMO系統(tǒng)中信道容量干擾受限的觀點(diǎn),為在頻譜資源有限的情況下提高系統(tǒng)吞吐量提供了一個(gè)新的研究方向。與傳統(tǒng)的資源平分不同,干擾對(duì)齊將來(lái)自不同基站的干擾在接收端進(jìn)行壓縮,從而使每個(gè)基站可以獲得更多的發(fā)送自由度(DoF,Degree of Freedom)。本文的研究主要關(guān)注于如何在實(shí)現(xiàn)干擾對(duì)齊的同時(shí)進(jìn)一步實(shí)現(xiàn)系統(tǒng)傳輸速率的提升。本文首先對(duì)現(xiàn)有的干擾對(duì)齊算法進(jìn)行了分析。實(shí)現(xiàn)干擾對(duì)齊的算法形式主要有兩種,閉合式干擾對(duì)齊算法和迭代式干擾對(duì)齊算法。閉合干擾對(duì)齊算法雖然設(shè)計(jì)簡(jiǎn)單,但是每個(gè)節(jié)點(diǎn)都需要獲得全局的信道狀態(tài)信息(CSI,Channel State Information)。迭代干擾對(duì)齊算法利用信道的互易性通過(guò)發(fā)送端和接收端的不斷迭代實(shí)現(xiàn)干擾對(duì)齊,每個(gè)節(jié)點(diǎn)只需要了解本節(jié)點(diǎn)的信道狀態(tài)信息,所以受到了非常廣泛的研究。迭代算法中基于最小干擾泄漏的干擾對(duì)齊使每個(gè)用戶接收到的來(lái)自其它基站的干擾強(qiáng)度最小,但是忽略了有用信號(hào)所經(jīng)歷的信道狀態(tài)信息;基于秩受限秩最小的干擾對(duì)齊算法雖然將干擾的秩壓縮到最小,并且保證每個(gè)基站獲得最大的發(fā)送自由度,但是并不能保證系統(tǒng)速率實(shí)現(xiàn)最優(yōu)。本文提出的優(yōu)化算法,是在保證系統(tǒng)自由度最大的情況下,實(shí)現(xiàn)系統(tǒng)速率的進(jìn)一步提高。利用系統(tǒng)速率優(yōu)化的非凸特性,將預(yù)編碼沿著吞吐量梯度方向進(jìn)行搜索,使預(yù)編碼沿著提高系統(tǒng)吞吐量上升的方向優(yōu)化。在迭代過(guò)程中隨著搜索步長(zhǎng)的不斷減小,算法近似退化為秩受限秩最小的干擾對(duì)齊,因此系統(tǒng)最終可以實(shí)現(xiàn)干擾對(duì)齊,并且系統(tǒng)吞吐量的提高。由仿真結(jié)果可以看出,相比已有的干擾對(duì)齊實(shí)現(xiàn)方案,本文提出的優(yōu)化算法在系統(tǒng)傳輸速率方面有明顯的提升。
[Abstract]:In recent years, with the continuous development of multimedia services and mobile intelligent terminals, the amount of wireless communication data has increased dramatically. Various techniques to improve spectral efficiency have been greatly developed. Among them, the multiple input multiple output (MIMOO) Multiple-Input Multiple-Output (MIMO) technology has attracted more and more attention because of its ability to effectively utilize spatial multiplexing gain to improve the transmission rate of the system. In order to improve the efficiency of the spectrum, the multiplexing factor of 1 is widely used to construct the network, so that the edge users in the cell will inevitably receive interference from other base stations and interference between multiple antennas. As a special form of interference coordination, interference alignment has become one of the research hotspots. Interference alignment breaks the view that channel capacity interference is limited in traditional MIMO systems. It provides a new research direction for improving the system throughput under the condition of limited spectrum resources. Different from the traditional resource sharing, interference alignment compresses the interference from different base stations at the receiving end. So that each base station can obtain more freedom of transmission. The research of this paper mainly focuses on how to achieve interference alignment while further improving the transmission rate of the system. Firstly, this paper focuses on the existing interference pair. The algorithm is analyzed. There are two kinds of algorithms to realize interference alignment. Closed interference alignment algorithm and iterative interference alignment algorithm. Although the design of closed interference alignment algorithm is simple, However, each node needs to obtain global channel state information / channel State information. Iterative interference alignment algorithm uses channel reciprocity to achieve interference alignment through continuous iterations at the sender and receiver. Each node only needs to know the channel state information of the node, so it has been widely studied. The interference alignment based on minimum interference leakage in the iterative algorithm makes each user receive the least interference from other base stations. However, the channel state information experienced by useful signals is ignored. Although the rank of interference alignment algorithm based on rank limited rank minimization can reduce the rank of interference to the minimum, and ensure that each base station obtains the maximum degree of freedom. But it is not guaranteed that the system speed can be optimized. The optimization algorithm proposed in this paper is to achieve further improvement of the system rate under the condition of ensuring the maximum degree of freedom of the system. The precoding is searched along the throughput gradient, and the precoding is optimized along the direction of increasing the system throughput. In the iterative process, as the search step size decreases, the algorithm is approximately reduced to the interference alignment with the minimum rank limited rank. Therefore, the system can eventually achieve interference alignment, and improve the system throughput. The simulation results show that compared with the existing interference alignment implementation scheme, the proposed optimization algorithm in the system transmission rate has significantly improved.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN972

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 劉乃金;邱玲;朱近康;;多小區(qū)MIMO系統(tǒng)中的一種主動(dòng)式干擾抑制方案[J];數(shù)據(jù)采集與處理;2008年06期

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本文編號(hào)：1670885