UMTS与LTE演进型移动网络规划与优化

5星 · 超过95%的资源需积分: 9 190 浏览量更新于2024-07-31 3 收藏 11.03MB PDF 举报

"Evolved Cellular Network Planning and Optimization for UMTS and LTE" 是一本专注于移动通信网络规划与优化的专业书籍，涵盖了UMTS（通用移动通信系统）、HSPA（高速分组接入）以及LTE（长期演进）等技术。本书旨在填补在这些技术领域中的知识空白，为读者提供全面而深入的介绍。书中首先对UMTS、HSPA和LTE网络进行了整体概述，包括基本的技术原理和信道模型。作者深入探讨了运营商和供应商在部署和管理这些网络时可能遇到的挑战，强调了网络规划和优化在解决这些问题中的关键作用。此外，书中的系统级仿真方法有助于读者理解和掌握有效的规划与优化技巧。内容亮点包括： 1. UMTS、HSPA和LTE网络的完整概览：详细介绍了这三种网络的架构、工作原理和技术特点，使读者能够对当前和未来的移动通信网络有全面的理解。 2. 网络规划与优化技术：提供了从初期规划到后期优化的全套流程，包括站点选择、覆盖预测、容量估算、干扰管理和性能调优等关键步骤。 3. 与现有网络的互操作性问题：探讨了如何处理UMTS、HSPA、LTE与其他传统网络（如GSM或TD-SCDMA）之间的互操作，确保不同制式间的平滑过渡和无缝连接。 4. LTE和中继网络部署的挑战：讨论了在部署LTE网络以及利用中继技术扩展覆盖范围时可能面临的困难，提供了应对策略。 5. 主要机制、趋势分析和故障排查：详细介绍了用于性能监控、问题诊断和性能提升的各种方法，帮助读者掌握实际操作中的技巧。 6. 无线电性能分析：提供了进行无线电性能评估的实用工具和方法，有助于优化网络质量和用户体验。 7. 兼容性问题：特别关注了不同网络间的兼容性，确保在网络部署和优化过程中能有效处理各种兼容性问题。作者Lingyang Song和Jia Shen分别来自Philips Research Laboratories和China Academy of Telecommunications Research，他们在移动通信领域有着丰富的经验和专业知识，使得这本书成为了一个宝贵的参考资料，对于从事网络规划、优化以及技术研发的IT专业人士来说，是一本不可或缺的指南。《Evolved Cellular Network Planning and Optimization for UMTS and LTE》不仅适合移动通信行业的工程师和规划者阅读，也适用于高校和研究机构的师生，作为深入理解现代移动通信网络及其优化的教材或参考书籍。通过本书，读者可以系统地学习和掌握从2G到4G演进过程中的关键技术，并为未来5G网络的规划和优化打下坚实的基础。

Saunder July 7, 2010 9:20 K10322˙C001

Introduction to UMTS: WCDMA, HSPA, TD-SCDMA, and LTE



One of the principle differences of UMTS compared to previous cellular systems

such as GSM is that it is designed to be a wideband system. In general, this means

that the transmission bandwidth is greater than the coherence bandwidth of the

radio channel. This is advantageous in terms of making the system more robust

against multipath fading and narrowband interference. In UMTS FDD mode, this

is achieved by means of a 5-MHz transmission bandwidth: Regardless of the data

rate of the application, the signal bandwidth is spread to 5 MHz to make use of the

full diversity of the available channel.

In Release 99, the TDD mode of UMTS also makes use of a 5-MHz carrier

bandwidth, but in later releases of the specifications other bandwidths were added:

the second release, known as “Release 4” (for alignment with the version number-

ing of the specification documents), introduced a narrower 1.6-MHz TDD carrier

bandwidth, while Release 7 added a 10-MHz TDD bandwidth. The 1.6-MHz op-

tion for TDD is used for the mode of UMTS known as time division-synchronous

CDMA (TD-SCDMA), which is introduced in Section 1.4.

The key features introduced in each release of the UMTS specifications are

summarized in Figure 1.3.

Regardless of the duplex mode or bandwidth option deployed, UMTS is struc-

tured around a common network architecture designed to interface to the same core

network (CN) as was used in the successful GSM system. The UMTS terrestrial

∗

radio access network (UTRAN) is comprised of two nodes: the radio network con-

troller (RNC) and the NodeB. Each RNC controls one or more NodeBs and is

responsible for the control of the radio resource parameters of the cells managed by

those NodeBs. This is a key difference from GSM, where the main radio resource

management functions were all provided by a single radio access network node, the

base transceiver station (BTS).

Each NodeB in UMTS can manage one or more cells; a common arrangement

comprises three 120

◦

-segment-shaped cells per NodeB, formed using fixed direc-

tional antennas. Higher-order sectorization may also be deployed, for example, with

6oreven 12 cells per NodeB. A deployment using three cells per NodeB is shown

in Figure 1.4.

The terminals in a UMTS system are known as user equipments (UEs). At any

given time, a UE may be communicating with just one cell or with several cells si-

multaneously; in the latter case the UE is said to be in a state known as soft handover,

which is discussed in more detail in Section 1.2.1.4. In order to facilitate mobility of

the UEs within the UMTS network, interfaces are provided between RNCs to enable

a connection to be forwarded if the UE moves into a cell controlled by a different

RNC. For a given UE, the RNC which is currently acting as the connection point

to the CN is known as the serving RNC (SRNC), while any intermediate RNC is

referred to as a drift RNC (DRNC). The main standardized network interfaces are

∗

Terrestrial as opposed to satellite.

Saunder July 7, 2010 9:20 K10322˙C001



Evolved Cellular Network Planning and Optimization

increases (spreads) the signal bandwidth to the desired transmission bandwidth. By

assigning different spreading sequences to different data flows, taking care that the

different spreading sequences have low cross-correlation between them, the signals

can be separated at the receiver even though they all use the same spectrum.

A simple example is shown in Figure 1.5, where two data flows are transmitted

from a base station, each data flow being destined for a different user and there-

fore being assigned a different spreading sequence. Each user’s receiver, knowing

its assigned spreading sequence in advance (by means of suitable configuration sig-

nalling), correlates the received signal with its spreading sequence over the duration

of each data symbol, thereby recovering the transmitted data flow. This process is

also known as despreading. The length of the spreading sequence is known as the

spreading factor (SF); hence the rate and bandwidth of the spread signal are SF times

the rate and bandwidth of the original data flow. The symbols after spreading are

known as chips, and hence the rate of the spread signal is known as the chip rate.

The chip rate is chosen to fit the available channel bandwidth (5 MHz in the case

of UMTS FDD mode), and the SF is set for each data flow depending on the data

rate, to increase the transmitted rate up to the chip rate. A low-rate data flow would

therefore be assigned a high SF, and vice versa.

Ideally, the spreading sequences would be fully orthogonal to each other (as is

the case with the example in Figure 1.5), thus resulting in no interference between

the different data flows, but in practice this is not always possible to achieve. One

reason for this is that insufficient orthogonal sequences exist of practical length; it

has been shown in [1] that the full multiple access channel capacity is achieved by

means of non-orthogonal sequences coupled with interference cancellation at the

receiver. Moreover, orthogonal sequences often exhibit other properties which are

less desirable. In particular, if it is desired to use the sequences for synchronization

of the receiver, a sharp single-peaked autocorrelation function is required, with low

sidelobes; orthogonal sequences often exhibit multiple peaks in their autocorrelation

functions.

A further factor affecting the performance of spreading sequences is lack of

time-alignment. Many types of orthogonal sequences are only orthogonal if they are

time-aligned. Lack of time-alignment can occur due to the transmitters not being

synchronized (in the case of the sequences being transmitted by different terminals

or base stations), but also due to different propagation delays in the radio channel.

The latter can also cause self-interference to occur even when only a single sequence

is transmitted, and equalization is required to remove such interference.

1.2.1.2 CDMA in UMTS

In UMTS, two families of codes are used for the CDMA spreading sequences:

orthogonal codes and non-orthogonal pseudo-noise (PN) codes.

The orthogonal codes are used for the spreading operation and are therefore

referred to as spreading codes. They have exactly zero cross-correlation if they are

剩余611页未读，继续阅读

harmoneer

粉丝: 0
资源: 1

UMTS与LTE演进型移动网络规划与优化

《Evolved Packet System (EPS) The LTE and SAE Evolution of 3G UMTS》 原版电子书 PDF格式

A Self-healing Approach for LTE Evolved Packet Core

HSPA and LTE for Mobile Broadband

Evolved.Packet.System.The.LTE.and.SAE.Evolution.of.3G.UMTS.2008

Wiley.Evolved.Packet.System.The.LTE.and.SAE.Evolution.of.3G.UMTS.Mar.2008

Design and analysis of collaborative EPC and RAN caching for LTE mobile networks

HSDPA HSUPA for UMTS

John.Wiley.&.Sons_WCDMA.for.UMTS.-.HSPA.Evolution.and.LTE.(4th.Ed)_2007.pdf

A unified protocol stack solutionfor LTE and WLAN in future mobile converged networks

epc_proto:LTE Evolved Packet Core (EPC) 协议库

最新资源

《Evolved Packet System (EPS) The LTE and SAE Evolution of 3G UMTS》原版电子书 PDF格式