Pbch, pcfich, phich, pdcch, pdsch, primary and secondary synchronization signals, reference signals. Familiar with key technologies adopted in ltelteadvanced, wimax, and umts systems, such as mimo, ofdm, scfdma, cdma, scheduling, link adaptation and harq. Sc fdma is the air interface which has been selected for the uplink in the latest long term evolution lte standard. For the uplink, umts lte will use scfdma single carrier frequency division multiple access technology. Physical sidelink broadcast channel matlab ltepsbch. Nonlinear analysis and digital predistortion of the sc. Introduction to scfdma and uplink frame structure marriage of single carrier transmission and fdma. As discussed in my previous post, in an ofdm system the data to be transmitted, x0, x1, xn1, is first modulated, typically using. As mentioned dft before ifft of ofdma and idft after dft of ofdma system make it sc fdma. The sidelink scfdma modulation processing in lteslscfdmamodulate performs ifft calculation, halfsubcarrier shifting, cyclic prefix insertions, and optional raisedcosine windowing and overlapping of adjacent sidelink scfdma symbols. Lte toolbox provides standardcompliant functions and apps for the design, simulation, and verification of lte, lteadvanced, and lteadvanced pro communications systems. A method for disrupting the pcfich is introduced in 9, using simulations for validation. Although still using a form of ofdma technology, the implementation is called single carrier frequency division multiple access sc fdma. Today, well talk about sc fdma, or singlecarrier frequencydivision multiple access.
Perform sidelink scfdma modulation of one subframe containing the sidelink synchronization signals and add noise at an snr of 3. I think this is a very good qualitative comparison between ofdma and scfdma. The goal of this course is to introduce the participant to those digital modulation methods, coding techniques, space, time and frequency diversity techniques and multiple access techniques presently in use or being. Why isnt scfdma used for downlink transmission in lte.
In this paper we discuss the implementation of a single carrier frequency division multiple access sc fdma transceiver running over the universal software radio peripheral 2 usrp2. Figure mentions modules unique to the sc fdma and in common with ofdma system. Implementation of lte scfdma on the usrp2 software defined radio platform. Also available are simultaneous pucch and pusch analysis as well as support for pucch format 3, a new control format added to 3gpp release 10. The dft makes scfdma a singlecarrier signal because the input to the idft is a spectrum already not qam symbols. Anritsu offers a complete line of lte test equipment that ensures the performance and quality of your lte equipment and networks. Lte is based on orthogonal frequency division multiplexing ofdm with cyclic prefix cp in the downlink, and on singlecarrier frequency division multiple access sc fdma with cyclic prefix in the uplink. Lte rf optimization training provides knowledge and skills needed for successful delivery of lte network design, lte planning and optimization activities. The function returns waveform, an sc fdma modulated waveform, and its corresponding information info. After synchronization a fully compensated signal is produced in the reference path pur ple which. Sc fdma is currently a strong candidate for the uplink multiple access scheme in the long term evolution of cellular systems under consideration by the third generation partnership project 3gpp. Also, 5g will mitigate the threat by removing the pcfich.
For v2x sidelink mode, the nominal length will be 504 resource elements it is defined for normal cyclic prefix only. In scfdma, the transmitter adds an msize fft stage before the ofdm transmitter. The mstage fft stage takes a single carrier channel and converts it into subcarrier level symbols that can be transmitted over an nstage ofdm system here m fdma and ofdma system. The same sequence of 62 complex values is repeated in each of the symbols, resulting in a 124by1 element vector returned by the ltessss. Research projects software libraries training materials. Lte ul receiver rf uplink receiver with rf demodulator. The mstage fft stage takes a single carrier channel and converts it into subcarrier level symbols that can be transmitted over an nstage ofdm system here m division multiple access scfdma with cyclic prefix in the uplink. However, realworld measurements would be required for a comprehensive assessment.
Scfdma is widely used in lte subscriber terminals in the transmit path and its variant ofdma is used in the enodeb downlinkor receive path of lte subscribers. Digital mobile and wireless communications radio interface for 4glte, imtadvanced, 5g course 016 request information about bringing this course to your site. Lte toolbox provides standardcompliant functions and apps for the design, simulation, and. This article provides an overview of the lte radio interface, together with a more indepth description of its features such as spectrum flexibility, multiantenna transmission, and intercell interference control. Scfdma in lte system signal processing stack exchange.
You can use this syntax for lte and multitone narrowband. About 3gpp lte wireless design library ads 2009 update 1. In sc fdma, the transmitter adds an msize fft stage before the ofdm transmitter. Singlecarrier frequency division multiple access scfdma has become a popular alternative to orthogonal frequency division multiple access ofdm in multiuser communication on lte uplink systems. The toolbox accelerates lte algorithm and physical layer phy development, supports golden reference verification and conformance testing, and enables test waveform. Energy, water, health, transportation and emergency services act as backbones for our society. The secondary sidelink synchronization signal ssss is transmitted in the central 62 resource elements of two adjacent sc fdma symbols in a synchronization subframe. The samsung lte system supports the downlink orthogonal frequency division multiple access ofdma transmission technology and the uplink single carrier sc fdma transmission technology in frequency division duplex fdd mode, and supports a scalable bandwidth for supporting various spectrum allocations to provide highspeed data services.
Nbiot transport and physical channels, physical signals, and scfdma modulation. Figure mentions modules unique to the scfdma and in common with ofdma system. However, this makes these critical infrastructures prone to cyber attacks, resulting in data leaks, reduced performance or even total system failure. Software option delivers comprehensive lte signal analysis. Every description i found so far refers to dft and idft. It is not possible to use ofdma on the uplink since, as told before, it presents a high peaktoaverage power ratio. The md8430a signaling tester is the first complete lte base station emulator. This was one of the main reasons for selecting scfdma as lte uplink. The long term evolution standard lte is a wireless communications, highspeed data standard for mobile phones and data terminals. Secondary sidelink synchronization signal matlab ltessss. As a result, an alternative to ofdm was sought for use in the lte. Cell search and selection in lte primary synchronization signal, secondary synchronization signal and reference. Like other multiple access schemes tdma, fdma, cdma, ofdma, it deals with the assignment of multiple users to a shared communication resource. Therefore, the result of the idft is a frequencyshifted singlecarrier signal.
These sidelink functions include support for release 12 devicetodevice d2d and release 14 vehicletoeverything v2x modes. Especially, scfdma is not necessary to implement fdma. Multiuser channel estimation for sc fdma system with cazac. An introduction to scfdma used by lte in uplink direction. Performance evaluation of lte physical layer using sc.
Ltebased iot demo at embedded world conference 2017. Lte phy lab models a bitbybit and samplebysample baseband processing for ue and enb physical phy layer in both downlink and uplink. Lte phy lab is a linklevel simulator providing comprehensive. Mimo precoding and ofdm scfdma modulation and extends it by possible 5g waveforms. Advantages and disadvantages of ofdm, ofdma and scfdma. Implementation of lte scfdma on the usrp2 software defined. Before the user equipment ue can communicate with the network, it must perform cell search and selection procedures and obtain initial system information. Lte for umts ofdma and sc fdma based radio access april 2009. Scfdma is the air interface which has been selected for the uplink in the latest long term evolution lte standard. If they are equal, they simply cancel out and it becomes a conventional singlel user single carrier system with frequency domain equalization. Plus umts lte is adding mimo antenna technology to the mix.
How the lte toolbox can be used to fully synchronize, demodulate and decode a live narrowband internet of things nbiot downlink signal. Frame synchronization, channel estimation, zf and mmse equalization, cell identity search, mib. Evolution steps of the 3gpp systems, the goals for lte. Lte uplink requirements differ from downlink requirements in several ways. Nutaq selected by nasa to supply softwaredesigned radio sdr nutaq announces joint collaboration for a 5g base station with viettel. Implementation of lte scfdma on the usrp2 software. Its basis stands in the gsmedge and umtshspa network technologies, with changes in terms of an increased capacity and higher speed by simplifying the core network and using a different radio interface. This behavior is consistent with the operation of the scfdma modulator which does not modulate the last scfdma symbol of the subframe. The demodulator zeros the resource elements in the last scfdma symbol. For the lte uplink, a different concept is used for the access technique. Modulated psbch symbols, returned as an n reby1 column vector n re is the number of resource elements in a subframe, including the sc fdma guard symbol, and is a multiple of 72. Physical signals sidelink synchronization signals psss and ssss, demodulation reference signals. I am trying to understand how scfdma is used in lte system. Jianqiang zeng technical advisor halliburton linkedin.
Id like to point out, that the whole purpose of scfdma is to reduce the papr. Singlecarrier fdma scfdma is a frequency division multiple access scheme. The mf6900a fading simulator provides a reproducible fading. N2 in this paper we discuss the implementation of a single carrier frequency division multiple access sc fdma transceiver running over the universal software radio peripheral 2 usrp2. Uplink downlink user 1 user 2 user 3 sc fdma ofdma figure 1. There are 7 sc fdma symbols for normal cyclic prefix and 6 sc fdma symbols for extended cyclic prefix. Aiming at high degrees of efficiency, these systems are increasingly automated, depending on communication systems. Single carrier frequency division multiple access scfdma. Channel estimation and correction methods for ofdma based lte.
One of the key parameters that affects all mobiles is that of battery life. 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. The high papr and related loss of efficiency associated with ofdm signaling are major concerns. While ofdm is used in many broadband technologies such as wimax16d16e, wlan11a11n11ac. This is primarily due to the low peaktoaverage power ratio papr of scfdma compared to that of ofdm. Lte physical layer tutorials lte long term evolution. Learn how undertake network performance improvement kpis and optimization tasks and create acceptance plan, sponsor best practices and ensure data integrity of various morphologytopography. Experimental analysis and simulative validation of. Lte phy lab is designed to serve customers at all stages of the lte software, hardware and ipr development, from research, prototyping and implementation, up to system benchmarking, verification and testing. Longterm evolution lte uses scfdma on the uplink to exploit this. Performance of scfdma for lte uplink under different modulation schemes. Together with the agilent 89600 vsa software, the option is the only analysis tool able to analyze both uplink sc fdma and downlink ofdma lte signals in a signal option.
The detailed specification of lte is given in table 1. Not surprisingly, power consumption is a key consideration for ue terminals. Nominally, n re is 576 for normal cyclic prefix or 432 for extended cyclic prefix. The papr issue led the lte designers to choose scfdma in the uplink direction. Scfdma was chosen because it combines the low papr techniques of singlecarrier transmission systems, such as gsm and cdma, with the multipath. Lte uses orthogonal frequency division multiplexing ofdm as its radio technology in downlink the physical resource can be seen as a timefreqqyguency grid in the uplink lte uses a precoded version of ofdm, scfdma single itsf 2008 14 in the uplink lte uses a. Performance analysis of scfdma and ofdma in lte frame. Performance analysis of scfdma and ofdma in lte frame structure. The 89600 vsa software with lteadvanced options enables enhanced uplink analysis capability with clustered scfdma, giving you the ability to add multiple clusters on the same slot. Single carrier frequency division multiple access scfdma for the uplink. Frequency division multiple access ofdma in downlink dl and single carrier frequency division multiple access sc fdma for uplink ul, as shown in figure 3. Modulated psbch symbols, returned as an n reby1 column vector n re is the number of resource elements in a subframe, including the scfdma guard symbol, and is a multiple of 72.