LTE-A異構(gòu)網(wǎng)絡中基于ABS配置和載波聚合的干擾協(xié)調(diào)方案研究
發(fā)布時間：2019-01-19 11:04
【摘要】：近年來,隨著移動智能終端的普及和各種實時多媒體業(yè)務的廣泛應用,寬帶無線網(wǎng)絡中的通信量以指數(shù)速率增長,隨之產(chǎn)生的是對更高覆蓋質(zhì)量、更高數(shù)據(jù)速率業(yè)務需求的增長。相對于用戶需求的快速增長來說,最嚴峻的問題就是頻譜資源的稀缺。為了提高頻譜利用率,LTE-Advanced (LTE-A)相比LTE進一步縮小了蜂窩尺寸,然而由于地形、建筑布局和其他條件的限制,蜂窩尺寸不可能無限縮小。尤其是對室內(nèi)、熱點區(qū)域、覆蓋盲區(qū)等特殊場景,只是簡單的縮小蜂窩尺寸并不能有效地解決問題。于是3GPP在LTE-A標準的制定過程中提出了異構(gòu)網(wǎng)絡(heterogeneous networks)技術(shù)用于解決上述問題,從而提升系統(tǒng)整體性能。 異構(gòu)網(wǎng)絡是一種全新的組網(wǎng)模式,由宏基站(Macro/MeNB)和其覆蓋范圍內(nèi)部署的微微基站(Pico/PeNB)、家庭基站(Femto)和中繼(Relay)等低功率節(jié)點混合組成。異構(gòu)網(wǎng)絡的部署拉近了終端用戶和基站節(jié)點間的距離,有效提高了單位區(qū)域內(nèi)的頻譜利用率,并能改善熱點區(qū)域、信號盲區(qū)和小區(qū)邊緣的通信質(zhì)量。異構(gòu)網(wǎng)絡作為一種極好的增強系統(tǒng)性能的方法,同時面臨著很多技術(shù)上挑戰(zhàn),其中由于網(wǎng)絡拓撲結(jié)構(gòu)的改變以及異構(gòu)網(wǎng)絡同頻部署帶來的小區(qū)間干擾問題尤為重要。 在Macro-Pico異構(gòu)小區(qū)場景下,由于Macro小區(qū)和Pico小區(qū)發(fā)射功率的差異,如果采用傳統(tǒng)的小區(qū)接入準則會導致Pico小區(qū)服務的用戶數(shù)非常有限,從而達不到部署Pico小區(qū)希望帶來的系統(tǒng)性能增益。因此,異構(gòu)網(wǎng)絡中引入了小區(qū)范圍擴展(Cell Range Expansion, CRE)技術(shù)來平衡Macro小區(qū)和Pico小區(qū)之間的負載。但是采用CRE技術(shù)以后,位于Pico小區(qū)邊緣的用戶,尤其是CRE區(qū)域內(nèi)的用戶會受到Macro小區(qū)強烈的下行干擾。因此本文提出將幾乎空白子幀(Almost Blank Frame, ABS)比例和CRE偏置值進行聯(lián)合優(yōu)化的增強型小區(qū)間干擾協(xié)調(diào)(enhanced Iner-Cell Interference Coordination, eICIC)方案,該方案根據(jù)小區(qū)間的負載情況調(diào)整CRE偏置,然后基于穩(wěn)定后的偏置調(diào)整ABS,找到使得系統(tǒng)吞吐量最大的ABS比例。 載波聚合是在LTE-A中提出的新技術(shù),通過聚合多個成員載波(Component carrier,CC)達到擴展系統(tǒng)帶寬的目的。LTE-A系統(tǒng)采用載波聚合技術(shù)后同時支持跨載波調(diào)度,既提高了調(diào)度的靈活性,又可以用于解決異構(gòu)網(wǎng)絡中的小區(qū)間干擾問題。本文提出一種基于載波聚合的干擾協(xié)調(diào)方案,讓Macro小區(qū)在部分載波的控制信道(CCH)上靜默,并保證在不損害系統(tǒng)整體性能的前提下,在這些載波的數(shù)據(jù)信道(DCH)上降低發(fā)射功率,以減輕對其覆蓋范圍內(nèi)Pico小區(qū)邊緣用戶的干擾。
[Abstract]:In recent years, with the popularity of mobile intelligent terminals and the wide application of various real-time multimedia services, the traffic in broadband wireless networks has increased exponentially, resulting in higher coverage quality. Higher data rate business demand growth. Relative to the rapid growth of user demand, the most serious problem is the scarcity of spectrum resources. In order to improve spectral efficiency, LTE-Advanced (LTE-A) further reduces the size of honeycomb compared with LTE. However, due to the constraints of terrain, architectural layout and other conditions, the size of honeycomb can not be reduced indefinitely. Especially for indoor, hot spot, blind area and other special scenes, simply reducing the size of honeycomb can not effectively solve the problem. So 3GPP put forward the heterogeneous network (heterogeneous networks) technology to solve the above problems in the process of establishing the LTE-A standard, so as to improve the overall performance of the system. Heterogeneous network is a new networking mode, which is composed of Acer Base Station (Macro/MeNB) and pico base station (Pico/PeNB) deployed within its coverage, home base station (Femto) and relaying (Relay), etc. The deployment of heterogeneous network can shorten the distance between the end user and the base station node, effectively improve the spectral efficiency of unit area, and improve the communication quality of hot spot, signal blind area and cell edge. As an excellent method to enhance system performance, heterogeneous networks are facing many technical challenges. Among them, the problem of inter-cell interference caused by the change of network topology and the co-frequency deployment of heterogeneous networks is particularly important. In the Macro-Pico heterogeneous cell scenario, because of the difference of the transmission power between the Macro cell and the Pico cell, if the traditional cell access criterion is adopted, the number of users serving the Pico cell will be very limited. Thus, the system performance gains that the deployment of Pico cells want to bring can not be achieved. Therefore, cell range extension (Cell Range Expansion, CRE) is introduced into heterogeneous networks to balance the load between Macro cells and Pico cells. However, after the adoption of CRE technology, users located on the edge of Pico cell, especially those in CRE area, will be strongly interfered by the downlink of Macro cell. Therefore, this paper proposes an enhanced inter-cell interference coordination (enhanced Iner-Cell Interference Coordination, eICIC) scheme, which optimizes the (Almost Blank Frame, ABS) ratio of almost blank subframes and the CRE offset value, which adjusts the CRE bias according to the load of the cell. Then, based on the stable bias adjustment ABS, we find the ABS proportion that makes the system throughput maximum. Carrier aggregation is a new technique proposed in LTE-A to expand the system bandwidth by aggregating multiple member carriers (Component carrier,CC). The LTE-A system uses carrier aggregation technology to support cross-carrier scheduling at the same time. It not only improves the flexibility of scheduling, but also can be used to solve the inter-cell interference problem in heterogeneous networks. In this paper, a interference coordination scheme based on carrier aggregation is proposed, in which the Macro cell is silent on the partial carrier control channel (CCH), and the overall performance of the system is not compromised. Transmission power is reduced on the data channel (DCH) of these carriers to mitigate interference to Pico cell edge users within their coverage.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN929.5
本文編號：2411310
[Abstract]:In recent years, with the popularity of mobile intelligent terminals and the wide application of various real-time multimedia services, the traffic in broadband wireless networks has increased exponentially, resulting in higher coverage quality. Higher data rate business demand growth. Relative to the rapid growth of user demand, the most serious problem is the scarcity of spectrum resources. In order to improve spectral efficiency, LTE-Advanced (LTE-A) further reduces the size of honeycomb compared with LTE. However, due to the constraints of terrain, architectural layout and other conditions, the size of honeycomb can not be reduced indefinitely. Especially for indoor, hot spot, blind area and other special scenes, simply reducing the size of honeycomb can not effectively solve the problem. So 3GPP put forward the heterogeneous network (heterogeneous networks) technology to solve the above problems in the process of establishing the LTE-A standard, so as to improve the overall performance of the system. Heterogeneous network is a new networking mode, which is composed of Acer Base Station (Macro/MeNB) and pico base station (Pico/PeNB) deployed within its coverage, home base station (Femto) and relaying (Relay), etc. The deployment of heterogeneous network can shorten the distance between the end user and the base station node, effectively improve the spectral efficiency of unit area, and improve the communication quality of hot spot, signal blind area and cell edge. As an excellent method to enhance system performance, heterogeneous networks are facing many technical challenges. Among them, the problem of inter-cell interference caused by the change of network topology and the co-frequency deployment of heterogeneous networks is particularly important. In the Macro-Pico heterogeneous cell scenario, because of the difference of the transmission power between the Macro cell and the Pico cell, if the traditional cell access criterion is adopted, the number of users serving the Pico cell will be very limited. Thus, the system performance gains that the deployment of Pico cells want to bring can not be achieved. Therefore, cell range extension (Cell Range Expansion, CRE) is introduced into heterogeneous networks to balance the load between Macro cells and Pico cells. However, after the adoption of CRE technology, users located on the edge of Pico cell, especially those in CRE area, will be strongly interfered by the downlink of Macro cell. Therefore, this paper proposes an enhanced inter-cell interference coordination (enhanced Iner-Cell Interference Coordination, eICIC) scheme, which optimizes the (Almost Blank Frame, ABS) ratio of almost blank subframes and the CRE offset value, which adjusts the CRE bias according to the load of the cell. Then, based on the stable bias adjustment ABS, we find the ABS proportion that makes the system throughput maximum. Carrier aggregation is a new technique proposed in LTE-A to expand the system bandwidth by aggregating multiple member carriers (Component carrier,CC). The LTE-A system uses carrier aggregation technology to support cross-carrier scheduling at the same time. It not only improves the flexibility of scheduling, but also can be used to solve the inter-cell interference problem in heterogeneous networks. In this paper, a interference coordination scheme based on carrier aggregation is proposed, in which the Macro cell is silent on the partial carrier control channel (CCH), and the overall performance of the system is not compromised. Transmission power is reduced on the data channel (DCH) of these carriers to mitigate interference to Pico cell edge users within their coverage.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN929.5
【參考文獻】
相關期刊論文 前1條
1 李俊;陳力;王彬;張欣;楊大成;;LTE-Advanced系統(tǒng)部署Pico后的小區(qū)間干擾協(xié)調(diào)技術(shù)[J];現(xiàn)代電信科技;2011年Z1期
，本文編號：2411310
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