In an ofdm system, the total available spectrum is divided into multiple carriers. Raj jain download long term evolution lte is a significant project of 3rd generation partnership project 3gpp, initially. Lte phy overview gwanmo ku adaptive signal processing and information theory research group nov. S4 allows direction of user plane between lte and geran utran uses gtp geran sgsn utran eutran mme non3gpp access serving gw pdn gw s1u s1mme s11 s3 s4 s5 internet eps core s12 sgi hss s6a s10 pcrf gx gxc. The normal cyclic prefix is intended to be sufficient for the majority of scenarios, while the extended cyclic prefix is intended for scenarios with particularly high delay spread. In fact, they differ only in the physical layer and, as a result, the version implemented is transparent to the higher layers. In recent years, ofdma based networks based on ieee 802. Overview of the 3gpp long term evolution physical layer. Ofdma can be used as a dl access scheme, with the mac layer assigning subchannels to the dl data destined to the various ues. Ofdma will be the predominant technology for the air interface of broadband mobile wireless systems for the next decades. Lte technologies drive new requirements for synchronization backhaul network technologies, topology and performance drive synchronization equipment and deployment decisions.
Ten paired and four unpaired spectrum bands have so far been. For the lte uplink, a different concept is used for the access technique. Long term evolution lte in 3gpp is the latest technology in cellular network that is being standardized. Ofdm forms the basic signal format used within 4g lte. Ofdm signal generation scrambling m odulation mapper codewords layers antenna ports lte physical layer model in matlab turbo channel coding mimo 1 ofdma adaptation of everything channel coding rate. Lteadvanced technology introduction white paper although the commercialization of lte technology began in end 2009, the technology is being enhanced in order to meet itu advanced requirements. Ofdma is an updated version of frequencydivision multiplexing technology used to divide packets of information into separate bands that are carried by separate signals. One of the key elements of lte is the use of ofdm orthogonal frequency division multiplex as the signal bearer, as well as ofdms associated access schemes, ofdma orthogonal frequency division multiple access and scfdma single carrier frequency division multiple access. Using multiple carriers, each carrying a low data rate, ofdm is ideal for high speed data transmission because it provides resilience against. Synchronization distribution architectures for lte networks. It is based on all internet protocol frame work that is not limited by past design.
Durations for the normal and extended cyclic prefix are. Specified in 3gpp release 8, the air interface for lte combines ofdma based modulation and multiple access scheme for the downlink, together with sc fdma single carrier fdma for the uplink. From the editors of the highly successful wcdma for umts, this new book gives a complete and uptodate overview of long term evolution lte in a systematic and clear manner. Ofdma orthogonal frequency division multiple access one of the key elements of lte is the use of ofdm orthogonal frequency division multiplex as the signal bearer, as well as ofdms associated access schemes, ofdma orthogonal frequency division multiple access and scfdma single carrier frequency division multiple access. Huawei lte for rail technical white paper page 4 1. Multiple access is achieved in ofdma by assigning subsets of subcarriers to individual users.
Lte the umts long term evolution a pocket dictionary of acronyms stefania sesia, issam tou. This application note gives an introduction to lte technology, including both fdd and tdd modes of operation. The detailed specification of lte is given in table 1. Lte tdd which is also referred to as td lte provides the long term evolution path for tdscdma based networks.
Ofdmtdma, ofdma, and multicarrier code division multiple access mccdma. Difference between 4g and lte compare the difference. A release 8 usim or lte usim is an usim which includes lte files specified in the release 8 of the 3gpp 31. It starts with an indepth explanation of the background and standardization process before moving on to examine the system architecture evolution sae. Long term evolution lte is a significant project of 3rd generation partnership project. While we do not yet have a description of the lte file format and what it is normally used for, we do know which programs are known to open these files. Ofdma scfdma in 4g lte part 2 streams of data, in the form of bits, reaches network gateway from various sources. The basic lte downlink physical resource can be seen as a timefrequency grid, as illustrated in figure below. Lte is based on orthogonal frequency division multiplexing ofdm with cyclic prefix cp in the downlink, and on singlecarrier frequency division multiple access scfdma with cyclic prefix in the uplink. Wcdma and ltewcdma and lte synchronization aspectssynchronization aspects the 6th international telecom sync forum, itsf munich, november 2008 stefano ruffini, ericsson. This paper provides an introduction to how the lte protocol stack operates.
Ofdma as 3gpp longterm evolution uplink friday december 4, 2009 ee359 project nima soltani 1. Long term evolution signaling flows and tutorials for lte protocol layers lte call flows lte enodeb s1 startup, mibsib broadcast and rrc connection learn about enodeb startup. To overcome the effect of multi path fading problem available in umts, lte uses orthogonal frequency division multiplexing ofdm for the downlink that is, from the base station to the terminal to transmit the data over many narrow band careers of 180 khz each instead of spreading one signal over the complete 5mhz career bandwidth ie. Scfdma was chosen because it combines the low papr techniques of singlecarrier transmission systems, such as gsm and cdma, with the multipath resistance and. Issue briefs are designed for practitioners with limited time and a need to know about the latest industrybased knowledge. With standard ofdm the subcarrier allocations are fixed for each user and performance can suffer from narrowband fading and interference. The name lte comes from the evolved universal terrestrial radio access network eutran. Lte release pertama tidak memenuhi persyaratan the imt advanced modul 4g lte. Implementing lte fddtdd convergence network in the age of. Myung 6 requirements of lte peak data rate 100 mbps dl 50 mbps ul within 20 mhz bandwidth. Lte phy overview electrical and computer engineering. Overview of the 3gpp long term evolution physical layer 1 1 introduction the 3gpp long term evolution lte represents a major advance in cellular technology.
Frequency division multiple access ofdma in downlink dl and single carrier frequency division multiple access scfdma for uplink ul, as shown in figure 3. Ofdma can also be used as an uplink access scheme, where specific subchannels are assigned to specific ues via mac messages sent on dls. This allows simultaneous lowdatarate transmission from several users. H2h, simulte, enodeb, overload congestion mechanism. Ofdm, orthogonal frequency division multiplex is the basic format used and this is modified to provide the multiple access scheme. In this case, you must set the preamble index to satisfy cyclic shift v as defined in 36. Annex 14 lte technical modelling revised methodology ofcom.
Lte also supports both fdd frequency division duplex and tdd. Physicalcommunication32010217244 219 table 1 lte,lteadvanced,andimtadvancedperformancetargetsfordownlinkdlanduplinkul. Umts long term evolution lte technology introduction. Written by experts actively involved in the 3gpp standards and product development, lte for umts, second edition gives a complete and uptodate overview of long term evolution lte in a systematic and clear manner. Sae system architecture evolution is the corresponding evolution of the gprs3g packet core network evolution. How lte organizes its symbols and subcarriers in the time and. According to 1 the desired lte signal will be raised to 70. The user has requested enhancement of the downloaded file. Ofdma, orthogonal frequency division multiple access in the downlink and scfdma, single channel orthogonal frequency division multiple access in the uplink.
Lte includes an fdd frequency division duplex mode of operation and a tdd time division duplex mode of operation. The baseband processing power that ofdm demands for both signal generation and demodulation is no longer a barrier to implementation, and in recent years systems have rapidly increased their. In ofdmtdma, timeslots in multiples of ofdm symbols are used to separate the transmissions of multiple users as shown in fig. An introduction to long term evolution lte by robert nibarger and mallorie teubner. Single carrier frequency division multiple access scfdma has been adopted by the third generation partnership project 3gpp for uplink transmission in technology standardized for long term evolution lte of cellular systems.
Although still using a form of ofdma technology, the implementation is called single carrier frequency division multiple access scfdma. Ofdma highlights lte uses ofdma for the downlink uses a large number of narrow subcarriers for multicarrier transmission robustness to multipath fading and interference resource blocks and elements each resource block and element is defined in frequency and time 1. Lte for umts ofdma and scfdma based radio access lte for umts ofdma and scfdma based radio access pdf, epub ebook d0wnl0ad from the editors of the highly successful wcdma for umts, this new book gives a complete and uptodate overview of long term evolution lte in a systematic and clear manner. The term lte is typically used to represent both lte and sae. I am looking for a clear and precise explanation of how an ofdma modulator in downlink lte operates.
S3 interface connects mme directly to sgsn for signaling to support mobility across lte and utrangeran. I have many books that explain it but each has its own way and do not answer my questions comple. Qualcomm incorporated includes qualcomms licensing business, qtl, and the vast majority of its patent portfolio. Each of these subcarriers is independently modulated by a low rate data. Lte is designed to meet carrier needs for highspeed data and media transport as well as highcapacity voice support well into the next decade. Orthogonal frequencydivision multiple access wikipedia. Key network component for mobile broadband service. Observed time difference of arrival otdoa positioning in.
This application note describes the physical downlink structure of mimo in lte with two antennas. Enhancement of the utra optimisation of the utran architecture to ensure the continued competitiveness of the 3gpp technologies for the future lte was the first and only technology recognized by the next generation mobile network alliance to meet its broad requirements target deployment in 2010. Voice over lte volte esting fttx networks table of contents. Introduction in order to transition from todays 3rd generation 3g communications systems to meet the needs of 4th. Lte as of release 8 supports mimo with up to four antennas. Number of samples in each symbol and cp varies with sampling rate. Orthogonal frequencydivision multiple access ofdma is a multiuser version of the popular orthogonal frequencydivision multiplexing ofdm digital modulation scheme. Orthogonal frequency division multiple access ofdma scheme is the transmission scheme used for lte fdd and lte tdd operational modes in the downlink. This means that ues will be able to support both td lte and fdd lte with one chipset with only minor modifications required. When users transmit, they occupy the whole frequency bandwidth.
This form of communication is an upgrade that parallels the switch of internet carriers to wifi 6 wireless, as well as the upgrade of phone carriers to 4g and 5g lte. High spectral efficiency is one of the key features of lte which was achieved using orthogonal frequency division multiple access ofdma with 64qam quadrature amplitude modulation technique. Principles of 3g cdma, 4g ofdma and 5g partb professor a. It provides a basis for advanced physical layer simulations in the areas like ieee 802. Voice and data communications work in tandem to prepare you for todays challenges and tomorrows unknowns. Materials that are as of a specific date, including but not limited to press releases, presentations, blog posts and webcasts, may have been superseded by subsequent events or disclosures. Progress on laa and its relationship to lteu and multefire. Update bearer request eps bearer identity, enodeb address, enodeb teid upon reception of both, the initial context response message and the attach complete message, the new mme sends an. Ofdma introduction and overview for aerospace and defense. Lte was initiated with the 3gpp release 8 freeze in march 2008, and further evolved in 9 and 10 releases. Single carrier frequency division multiple access scfdma is a promising technique for high data rate uplink communication and has been adopted by 3gpp for it next generation cellular system, called longterm evolution lte.
The various synchronization needs, the available synchronization solutions, and their applicability to small cells deployed in long term evolution lte timedivision duplex tdd and lte frequencydivision duplex fdd networks are discussed in this article. This white paper summarizes these necessary improvements specified in 3gpp release 10, which are also known as lteadvanced. Ofdma incorporates elements of time division multiple access tdma so that the subcarriers can be allocated dynamically among the different users of the channel. Every day thousands of users submit information to us about which programs they use to open specific types of files. Voice over lte volte esting fttx networks featuring pons systems sdfsdf table of contents 1. Building upon on the success of the first edition, lte for umts, second edition has been revised to now contain improved coverage of the release 8 lte details, including field. It is intended as a one stop guide to provide an overview of the otdoa feature for operators and manufacturers interested in the deployment. You can use this syntax for lte, singletone nbiot, and multitone nbiot configurations. This document describes the functionalities for the support of otdoa location in lte as currently defined in 3gpp and oma. Lte specifies both normal and extended cyclic prefix lengths.
Lte is built on an all new radio access network based on ofdm orthogonal frequency division multiplexing technology. Lte stands for long term evolution and it was started as a project in 2004 by telecommunication body known as the third generation partnership project 3gpp. The resource blocks have a total size of 180khz in the frequency domain and 0. Lte or long term evolution is the brand name given to the efforts of 3gpp 4th. In this tutorial article, we discuss the reasons for the popularity of ofdma and outline some of the important concepts which are used in ofdma as applied to bcw systems. Synchronization needs in mobile backhaul different types of synchronization exist. This page covers excel sheets 11n data rate table, fixed wimax bandwidth table, mobile wimax bw with fs, 16e data rate calculator, evm conversions, pdf ppt files ofdm versus ofdma,osi,rrh,11a physical layer,router, beamforming and projects in matlab and simulink. Lte a an overview and future research areas shihab jimaa college of engineering, khalifa university of science, technology and research u. Ofdm ofdma in 4g lte part 1 how can we stream a full hd movies seamlessly. Qualcomm products referenced on this page are products of qualcomm technologies, inc.