【正文】 tf38 中繼在 LTEA中的應用 （1） ? 中繼的引入 ? LTEA系統(tǒng)帶寬很大，功率和覆蓋范圍嚴重受限 ? 用傳統(tǒng)的微基站方式改善各種覆蓋問題成本仍然較高 ? 而普通直放站在放大信號的同時放大干擾 ? 中繼的應用場景 ? 盲點 /建筑物內 /陰影 /建筑峽谷 /小區(qū)邊緣 ? 移動交通工具，如鐵路 /公共交通 ? 臨時組網 ? 中繼的優(yōu)勢 ? 改善覆蓋 ? 增加容量，提升系統(tǒng)頻譜效率 ? 采用無線回程，無需挖溝布線，只需要供電支持 39 ? 中繼作為 LTE R10的一個重要特征正在 3GPP進行深入的研究 ? 使用的頻段 ? Inband —— 接入鏈路和中繼鏈路使用相同的頻段 ? Outband—— 接入鏈路和中繼鏈路使用不同的頻段 ? 中繼分為兩種類型： ?Type1中繼 ?具有獨立的小區(qū) ID，發(fā)送自己的導頻和同步信號 ?實際意義上的支持無線 Backhaul的小型基站 ?用于擴展覆蓋和補盲等 ?Type2中繼 ?沒有獨立的小區(qū) ID，不發(fā)送自己的導頻和同步 ?支持不同的物理層協(xié)作通信方式 ?用于增加小區(qū)吞吐量和頻譜效率 中繼在 LTEA中的應用 （2） 40 ? At least ―Type 1‖ relay nodes are part of LTEAdvanced. ? A ―type 1‖ relay node is an inband relaying node ? Relay node (RN) creates a separate cell distinct from the donor cell ? UE receives/transmits control signals for scheduling and HARQ from/to RN ? RN appears as a Rel. 8 LTE eNB to Rel. 8 LTE UEs ? Deploy cells in the areas where wired backhaul is not available or very expensive eNB RN UE Cell ID x Cell ID y Higher node Type 1 Relay 41 Type 2 Relay ? A ―type 2‖ relay node is an inband relaying node characterized by the following: ? It does not have a separate Physical Cell ID and thus would not create any new cells. ? It is transparent to Rel8 UEs。 a Rel8 UE is not aware of the presence of a type 2 relay node. ? It can transmit PDSCH. ? At least, it does not transmit CRS and PDCCH. 42 異構網絡技術 ? 異構網絡（ Heterogeneous Networks， HetNet ）： In order to meet the performance requirements for LTEA , a mon theme discussed by multiple panies was the incorporation in the system of new nodes with transmit power class lower than the usual ―macro‖ eNBs. These new nodes (pico cells, Home eNBs, relays) change the topology of the system layout to a much more heterogeneous work with a pletely new interference environment with nodes of multiple classes ―peting‖ for the same wireless resources. Backhaul Access Notes Remote radio head (RRH) cells Several 181。s latency to macro Open to all UEs Placed outdoors Hotzone cells X2 Open to all UEs Placed outdoors Femto cells FFS Closed Subscriber Group (CSG) Placed indoors Relay nodes Through airinterface with a macrocell (for inband RN case) Open to all UEs Placed outdoors 43 ? LTEAdvanced will focus on local areas rather than wide area cellular cells ? Using small cells is effective ―technique‖ to significantly increase capacity and coverage especially where traffic density is not uniform [1] ? Microcells, picocells including femtocells, etc. Intercell Interference in Heterogeneous Networks Intercell interference (ICI) management among different types of cells will be key in LTEAdvanced Between macrocells Between macro and microcells Between micro and picocells [1] Qualm, R1081956 44 異構網絡應用場景 Case Environment Deployment Scenario Nontraditional node Macro + Indoor Macro + femtocell femtocell Macro + indoor relay Indoor relay Macro + indoor RRH/Hotzone . indoor pico Macro + Outdoor Macro + outdoor relay Outdoor relay Macro + outdoor RRH/Hotzone ., outdoor pico 45 Femto / Home eNodeB ? 為室內用戶提供很高的吞吐量 ? 擴展室內覆蓋 ? 增加室內和室外的容量 Macro NodeB Outdoor UE Indoor UE Macro NodeB Home NodeB Outdoor UE Indoor UE 引入 Femto小區(qū)之前 引入 Femto小區(qū)之后 0 200 400 600 800 1000 1200 1400 1600 1800 2022 0 400 800 1200 1600 2022 システムスループット [kbps] ユーザスループット [kbps] Indoor 1Mbps Before introducing femto cells Cell Throughput HSDPA User Throughput After introducing femto cells Outdoor 示例 : 引入 Femto小區(qū)之后 HSDPA（ category6）的用戶吞吐量在室外增加 ，在室內增加。 46 ? Femto又稱毫微微小區(qū)， femto作為一種新興的熱點技術，被業(yè)界認為是解決室內覆蓋的有效手段之一，也是固定和移動融合的一種方式。 ? Femto設備發(fā)射功率小，最大功率 20mW。 ? 目前采用的室內覆蓋的方式是信號源加室內分布系統(tǒng)，適用于辦公樓、隧道等對容量要求很高的大型建筑場景；對于居民樓、別墅等家庭建筑環(huán)境，采用傳統(tǒng)的室內分布系統(tǒng)方式顯然是不現(xiàn)實的。 Femto擺脫傳統(tǒng)方式的束縛，可以有效的解決家庭環(huán)境的室內覆蓋問題。 Femto / Home eNodeB 47 歡迎探討 ！