Radio Resource Scheduling: The most important objective of LTE scheduling is to satisfy Quality of Service (QoS) requirements of all users by trying to reach, at the same time, an optimal. A non-exhaustive list of. The HI all,Please go through video of LTE Frame Structure (FDD and TDD). Like 4G, the frame is 10ms long with 1ms subframes, but it is a lot more flexible but also more complex. Figure 1 shows frame structure type 1, which can be used in either full-duplex or half-duplex FDD mode. It introduces several changes in terms of frame structure and slot formats compared to previous generations like 4G LTE. It does not show any structure in frequency domain. Following equation is based on 36. The skeleton is on example of a frame structure. Figure 1: LTE Generic Frame Structure [3] 2. This allows LTE technology to fit within either existing or new carrier spectrum allocations. In 5G/NR, we don't have any predefined pattern. When you study the physical frame structure of LTE, you may be impressed by flexibility (meaning complexity in other way) of all the possible ways of resource allocation. Selection of a frame formatLTE: Key Features (Cont) 8. How about SSB? We can. The resulting location of the process is as shown in Reference Signal section of Downlink Frame Structurepage. ii) System Frame Number (SFN) iii) PHICH Configuration. The overall feature of NB IoT is now outlined in 3GPP RP-151621 as follows. 3GPP LTE Frame Structure 1, Applicable to TDD and FDD Note (1) Note to Figure 1: (1) For more information, refer to 3GPP Technical Specification 36. 1. LTE standard has been published by 3GPP as an extension of UMTS (based on 3GPP standard) and 1xEV-DO (base on 3GPP2 standard. 211 V16. Each slots can have a number of symbols (7 symbol for normal CP/ 6 for extended CP for LTE and 14 OFDM symbols in 5G). 4 Frame structure type 2 177 8. The highest level view from 36. 1), where the downlink and uplink transmissions are per-formed in different carrier frequencies. In TDD (Time division duplex) technique we are using, same frequency or frame for both DL and UL but at a different time. iv) System Frame Number for each frame from P-CCPCH (MIB) Once UE get all the information listed above, the timing for other channels can be deduced by the following diagram (This diagram came from 3GPP TS 25. One Radio Frame is made up of 10 subframes. Basic time unit Ts for BW of 20MHz, (1/15000)*2048 seconds equal to 32. Some of high level description you can get from this figure would be . This generic frame structure is used with FDD. 5ms duration. The PHY. If the PDCCH is for a specific UE, the CRC will be masked with a UE unique identifier, for example a Cell. It enables very low latency, fast HARQ acknowledgments, dynamic TDD, coexistence with LTE and transmissions of variable length (for example, short duration for URLLC and long duration for enhanced MBB (eMBB)). 5), there is a single carrier frequency and uplink and downlink transmissions are separated in the time domain on a cell basis. 1-1: Mapping between cell-identity group and the indices m0 and. from below figure you can see for μ = 0 (highlighted row) Number of OFDM symbols in one slot = 14. 5 ms. The chapter concludes with an end‐to‐end procedure of when the UE powers‐up in an LTE network, interchanging data with the network and mobiles around. • The figure-1 depicts overall time frame structure used in NB-IoT AS (Access Stratum). – Frame structure type 2 (FS2): TDD. Data Rate: 326 Mbps/down 86 Mbps up (4x4 MIMO 20 MHz) 9. LTE FRAME STRUCTURE AND SIGNAL MODEL A. 101: “Evolved Universal Terrestrial. Type 1 radio frame has a duration 10 ms and consists of equally sized 20 slots each of 0. 25 MHz. The LTE uses 2 CP sizes – Normal. The performance comparison of the different 5G NR numerologies at various speeds and frequencies and within most common 5G scenarios was made with 1000 transmission time intervals (TTI) per numerology, using the PHY layer parameters of LTE and adjusting the frame structure with the parameters of the. 4G, 4. LTE tutorial videos, articles, and code examples introduce key LTE concepts and effective techniques and workflows for LTE physical layer development including: Waveform generation. System Information. As shown in Fig. Because of variable subcarrier spacing, the. In FDD there will be pair of frequencies assigned in the downlink and uplink directions and hence transmissions from multiple subscribes can happen at the same time but on different frequencies as mentioned. The LTE specifications define both FDD and TDD modes of operation. 1. A. For TDD, a subframe is either allocated to downlink or uplink transmission. It improves on those standards' capacity and speed by using a different radio interface and core network improvements. Low Layer Procedures DCI HARQ PHY Processing MIMO MIMO/CA(Big Pict. One GSM hyperframe composed of 2048 superframes. (Please refer to diagram for better understanding) 1) In time domain, 1 Radio frame (RF) is of 10 ms. LTE frame structure OFDM to address multi-path fading. Frame Structure Understanding the 5G NR Physical Layer Waveform, Numerology and Frame Structure 21 – Frame: 10 ms – Subframe: Reference period of 1 ms – Slot (slot based scheduling) • 14 OFDM symbols • One possible scheduling unit - Slot aggregation allowed • Slot length scales with the subcarrier spacing The air interface described in the chapter covers the concepts of LTE frame structure, downlink and uplink scheduling, and detailed illustrations of the data flow across the protocol layers. Type 1 lasts 10 ms equivalent to 10 subframes. 5ms [9]. 5 kHz UL shift . Frame structure 2 is commonly used. Like LTE-U, this is a kind of technology to transmit LTE signal in unlicensed frequency range. Instead, we can define the pattern in much more flexible way using several parameters as shown below. The duration of each subframe is 1 ms. Tables defining Uplink Frame Structure . Special Subframes Radio Frame Length = 10 ms. S. – Frame structure type 1 (FS1): FDD. - available for PMCH (Physical Multicast Channel) LTE Resource Grid. Myung 17 Frame Structure • Two radio frame structures defined. Deciding on LTE vs 5G depends greatly on the use cases one expects from the network, as well as one’s budget and location. 2. In 5G/NR, we don't have any predefined pattern. Total Frame duration is about 10ms. Downlink modulation types: QPSK, 16-QAM, and 64-QAMthe LTE communication protocol. 2. 2) There are 10 Sub-frames in each Radio frame. 6, the downlink subframe structure in LTE consists of an LTE control region and an LTE data region. Each frame composed of 4 time slots. 10 mili second radio frame consists of Downlink subframe, Uplink subframe and Special subframe. • LTE Frame Structure • LTE Resource Grid • LTE Bandwidth/Resource Configuration • LTE Channels • LTE Protocol Architecture . Slot duration=0. The design considera-tions are explained below. INHA UNIVERSITY. . k) that the frame structures given in Annex 1, Frame A and Frame B can be implemented for NR(New Radio) systems; l) that the Frame B2 given in Annex 1 is compatible with the LTE-TDD frame structure configuration n o. In 5G NR, there is the concept of flexible TDD uplink and downlink sub-frame allocation. 5G NR: Numerologies and Frame structure Supported Transmission Numerologies - A numerology is defined by sub-carrier spacing and Cyclic-Prefix overhead. KPI & Features Frame Structure Downlink Time Domain Frame Structure Downlink Time Domain Cont. The air interface described in this book covers the concepts of LTE frame structure, downlink and uplink scheduling, and detailed illustrations of the data flow across the protocol layers. The cyclic shifts are generated based on cell-identity group number, which. 211 frame structure type 2 (DL / UL / SSF) Filter. In LTE base station is referred as eNodeB and mobile subscriber is referred as UE. Each frame is divided into 10 subframes of 1 millisecond, and the subframe is further divided into slots according to numerology. 04/02/2023 10 Types of Frame Structure in LTE: • Types of Frame structure in LTE: 3GPP defines two types of frames based on the duplexing scheme used. Prasad. One is the type which is more like current LTE/LTE-Advanced and the other type is for new waveform. Particular attention is given to LTE’s use of multiple antenna techniques and to the modulation scheme called single carrier frequency division multiple access (SCFDMA). MCCH Info. Some parameters do not apply to the Basic LTE PRACH and Basic LTE-A PRACH. But now, with the introduction of LTE system toolbox [7], the parameters. However, unlike LTE, which has a fixed subcarrier spacing (SCS) of 15 kHz, 5G NR supports scalable numerology for more flexible deployments covering a wide range of services and carrier frequencies. The uplink and downlink bands are separated in the frequency domain using a guard band. In LTE, the subframe number and OFDM symbol number within the subframe is always same in any cases). Subframes #0 and #5 are always assigned to DL, and subframe #2 is always assigned to UL. We. · Each Radio frame consists two half frames. Learn the basics behind 5G NR waveforms, frame structure, and numerology. OFDMA Downlink. 5 msec. 27/06/2023 0. , Frame Structure Type 3) was introduced to facilitate unlicensed spectrum operation consisting of 10 subframes of length 1 ms as illustrated in Fig. One slot is defined as 14 OFDM symbols, which corresponds to once a frame or one millisecond in LTE. LTE Frame Structure. Channel Mapping. Timing Advance in LTE . Here, the idea is to compress the whole transmission chain of waiting for a transmit opportunity and preparing for a transmission, transmitting the data, and finally processing the received data. Portal frames look like a door. Expected in the 2008 time frame, LTE is a 3GPP standard that provides for an uplink speed of up to 50 megabits per second (Mbps) and a downlink speed of up to 100 Mbps. . This LTE tutorial covers LTE basics, LTE features, LTE air interface, LTE channels and LTE frame structure. Uplink 3. Answer-1:The difference lies in the LTE frame structure in both the FDD and TDD versions of the LTE. Download scientific diagram | LTE Frame Structure for FDD Systems. The 5G NR frame structure depicts subframes,slot and symbol configurations. It is composed of 20 slots of 0. For example, the public network has more downlinks, and the private network or private network has more uplinks. 3 Downlink frame structure 190 9. These two frames, which are incompatible with each other, will require new functionalities to avoid interference at borders. 4MHZ. Type 1 is used as LTE FDD frame structure. 211 V1. • A resource block (RB) spans 12 subcarriers over a slot duration of 0. For the examples of TDD resource grids for each Subframe DL/UL Configuration and Special Subframe Configuration, see Frame Structure Frame Type 2 Overview section. Learn the details of LTE-NB frame structure for downlink operation mode, including the subframe mapping, the reference signal, the NPBCH, NPSS and NSSS. (Basic LTE-A) Simultaneous PUCCH and PUSCH (Advanced LTE) Scalable bandwidth: 1. End-to-end simulation and conformance testing. • Transmitted on 6th symbol of slot 0 and slot10 of each radio frame on 72 subcarriers centered. In LTE, only 2 slots are available. The first choice has the advantage of compatibility with the LTE frame structure used by French networks and The second choice is not compatible with LTE. To address these challenges, we propose a novel frame structure design that incorporates several key changes relative to current LTE systems: Flexible TTI duration: The current LTE system uses a fixed transmission time interval (TTI) of one subframe (1 ms). When an LTE system in one country is within the footprint of a satellite service owned by another country, to prevent the interference from the satellite services, the LTE system will avoid using the overlapped frequency bands. The general idea is that the LTE subframe is made up of PDCCH and PDSCH as explained in my article LTE Frame Structure Made Simple. dl-UL-TransmissionPeriodicity. Each subframe has a length of 1 ms, which comprises 30,720 complex time-domain baseband samples sampled at a rate of 30. 5G NR: Numerologies and Frame structure Supported Transmission Numerologies - A numerology is defined by sub-carrier spacing and Cyclic-Prefix overhead. These two frames, which are incompatible with each other, will require new functionalities to avoid interference at borders. To configure the downlink signal in this slot pattern, two separate DL-SCHs will be needed to represent two different channel. i) Time duration for one frame (One radio frame, One system frame) is 10 ms. We discuss LTE basics including the LTE frame structure, OFDMA, Resource elements, Resource blocks and Scheduler Resource blocks. LTE FDD uses 10ms frames, divided into 20 sub-frames or slots (of 0. The UE and eNB communicate with each other based on the radio frame structure, as shown in Figure 22. This site is for everything on 4G/LTE. Type 1, applicable to FDD- Here there are. A typical LTE frame is 10 ms (milliseconds) long. 3. The OFDMA system model is shown in Figure 1. Figure 3 shows the frame structure for LTE in FDD mode (Frame Structure Type 1). 0. There can be a variable number of slots per subframe, with 14 OFDM symbols per slot. Type 2: used for the LTE TDD systems. of slots=20. As shown one hyperframe cycle consists of 1024 hyperframes. Selection of a timing reference (beginning of the frame) b. The GSM frame structure is designated as hyperframe, superframe, multiframe and frame. The Long Term Evolution (LTE, 4G ) standard defined by the 3GPP supports both FDD and TDD Duplex mode. Mapped to 72 active sub carriers(6 resource blocks), centered around the DC subcarrier in slot 0 (Subframe 0) and slot 10 (Subframe 5) in FDD. Each subframe has two slots. We show that this fixed TTI duration is extremely inefficient whenLTE FRAME STRUCTURE Bikas Singh 5y 5G NR Terminologies – Subcarrier Spacing, Fram-Subframe, Slot and Symbol K. 1. 10 Variable Subcarrier Spacing Slot configuration 0 Subcarrier spacing (kHz) 15 30 60 120 240 Symbol duration (no CP) (μs) 66. Frame Structure - Candidates before 3GPP . There are two types of frames in LTE;FDD and TDD. 2. LTE will bring many. Slot duration=0. It describes both TDD band and FDD b. Refer to 36. 10 mili second radio frame consists of Downlink subframe, Uplink subframe and Special subframe. The basic type 1 LTE frame has an overall length of 10 ms. 3) is used for Frequency Division Duplex (FDD) mode; however, the type 2 structure (Fig. It include WiMAX, WLAN, Zigbee, GSM, GPRS, UMTS, LTE, TD-SCDMA, GPS, SDH, 11ac WLAN, AMPS, Ethernet, VLAN etc. As seen in the figure, in each frame some subframes are allocated for uplink transmissions and some subframes are allocated for downlink transmission,. FDD and TDD mode can be combined (depends on UE capabilities) in the same physical layer. It does not show any structure in frequency domain. Frame-Structure in LTE. 5 kHz UL shift . In LTE, only 2 slots are available. 11 devices. The first choice has the advantage of compatibility with the LTE frame structure used by French networks and The second choice is not compatible with LTE. In order to make use of the overlapped LTE bands, a Downlink Only Frame Structure (DOFS) approach is proposed in this. In TDD, one single frequency will be. 4G/LTE - PHY Channel PSS (Primary Synchronization Channel) PSS is a specific physical layer signal that is used for radio frame synchronization. Download scientific diagram | shows the frame structure of LTE V2X. How many Time-Slot are present in Sub-Frame? Q04. The downlink channels are PBCH, PDSCH, PDCCH, PMCH, PCH etc. Network Components for MBSFN(eMBMS) For implementing eMBMS, a couple of components are added in the core network side as shown below. In LTE, the subframe number and OFDM symbol number within the subframe is always same in any cases). LTE FDD. when μ = 0. Base stations need to. There are two cell search procedures in LTE: one for initial synchronization and another for detecting. 7 33. It compares both with respect to application,frame structure, Guard period,frequency band,interference,data rate and. Additionally, we assume that the LTE communications use Time Division Duplex (TDD), in which the radio frame structure is illustrated in Figure 2. If you are interested in some historical aspects of the 5G Frame structure, it would be good to read through this. No. In 5G NR, similar to LTE, a radio frame is fixed at 10 milliseconds (ms) and consists of 10 subframes, each of which is 1 ms long. A TDD frame structure is shown in below figure. · It consists in a category of Frame 2. 5 ms. 5 ms. Telecom. RACH is responsible for the Random-Access process. Signal analysis. 7. Slot duration=0. The LTE frame structure for the FDD and TDD schemes was discussed in Chapter 9. In this example we will be simulating what happens when a mobile phone is turned on. 11. Outline . Similar as most of the previous researches [8, 9, 11, 15, 16], only downlink communication is considered in this work. The LTE physical layer supports two types of frame structures as types 1 and 2. The performance comparison of the different 5G NR numerologies at various speeds and frequencies and within most common 5G scenarios was made with 1000 transmission time intervals (TTI) per numerology, using the PHY layer parameters of LTE and adjusting the frame structure with the parameters of the. A. Each frame is divided into 10 subframes of 1 millisecond, and the subframe is further divided into slots according to numerology. 211: “Physical Channels and Modulation” - 3GPP TS 36. BCCH Info. between LTE and NR, then point out the limitations in supporting sharing over SL, and possible solutions in 3GPP standard efforts. As mentioned as per topologies, TDD and FDD there are two frame structures viz. Hi All,There are lot of new member joined so i am providing the links of ORAN videos whi. 2. Each radio frame is divided into 10 subframes (each being 1ms long). This Sync detection is done every 5 ms. It describes the details of the optimization process including performance measurements and troubleshooting mechanisms in addition to demonstrating common. Determine frame synchronization and cell identification (cell search procedure) based. Type 1, applicable to FDD- Here there are. As shown one hyperframe cycle consists of 1024 hyperframes. LTE frames are 10 msec in duration. S. Moreover, each. V. It consists of 20 equal-sized time slots. (As you know, one sample (Ts) is 1/30. Fig. 1. 5 99 198 396 397. The Input Sampler samples the inputs NDLRB and NCellID and then propagates the values to the subsequent blocks. 5 ms each. 3 Context management over S1 14 6. Dynamic part is called as SIB and is mapped on RRC SI messages (SI-1,2,3,4,5,6,7,8,9,10,11) over DL-SCH and transmitted using PDSCH at periodic intervals. Frame Structure - Candidates before 3GPP . 1 Numerologies, Frames, Subframes, and Slots 11 4. The 51-frame Control Channel Multiframe in GSM. THE Mobile Broadband Standard. Frame Structure • Two radio frame structures defined. Bits are transmitted serially. Define Frame Structure? Q02. So LTE need to keep the rule set by 802. The duration of each subframe is 1 ms. dl-UL-TransmissionPeriodicity: Periodicity of the DL-UL pattern. The Evolved Packet Core (EPC). How to deal with SSB ? In case of NR PDSCH transmission in DSS mode, most of the problems (especially problems of collision with LTE frame structure) were resolved by tweaking NR side (like punctuation/rate matching of NR data). The CRC is then masked with an RNTI according to the owner or usage of PDCCH. g. 211 frame structure type 2 (DL / UL / SSF) Filter. Performance Results. 12 6. One resource block is 0. LAA . Sub frame duration=1 ms. cyclic prefix). 5 Downlink distributed transmission 178 8. 211 for FDD LTE is as follows. 4G-LTE packet structure. LTE defines a generic frame structure that applies to both DL and UL for FDD operation. The frame structure is divided into three types: FDD, TDD, FDD and TDD. What is VSWR. The structure of the HDL LTE MIMO Transmitter subsystem is shown below. LTE-V2X PHY-layer Structure 10 LTE frames divided into 1 subframes Channel divided into resource blocks (RBs) 180 kHz RB contains:. LTE uses OFDMA for the downlink, with a fairly simple frame structure, and SC-FDMA for the uplink. 1 Downlink physical layer The LTE downlink PHY is specified for bandwidths from 1. This article presents an overview of the LTE physical layer with a focus on essential aspects of the physical layer for FDD mode, which is the dominant mode of operation. Two duplex schemes FDD and TDD are supported. 2) Frame Structure The 5G frame structure is conceptually like LTE, but it is more flexible to accommodate the different requirements for high-speed and low-latency operation. Subchannels separation is Δ f =15kHz. No of Slots per Sub frame =2. Downlink Reference - 3GPP TS 36. Figure 1 LTE Frame structure . Some parameters do not apply to the Basic LTE PRACH and Basic LTE-A PRACH. PRACH Preamble Format . LTE Duplex Specific 17. There are total 10 subframes in a frame. This video looks at OFDM waveforms, and the different subcarrier spacings supported in 5G NR. Figure 2: LTE frame structure type 1 [2] LTE frame. However, unlike LTE-U, LAA use a special physical layer frame structure called Frame Structure Type 3 which didn't exisit before. In the time domain the LTE transmissions are organized into frames of 10 msec length. The mobile equipment has the following core modules: All communication functions are handled by Mobile Termination (MT). Supporting WiFi and LTE Co-existence Sangki Yun, Lili Qiu The University of Texas at Austin Abstract—Motivated by the recent push to deploy LTE in. . Uplink Frame Structure of LTE-NB can be summarized in the following three tables. In this example we will be simulating what happens when a mobile phone is turned on. 5 ms Sub frame duration=1 ms. 2. 300 Figure 4: Overall Architecture eNB = E-UTRAN Node B All radio interface-related functions MME = Mobile Management entity – Manages mobility, UE identity, and security parameters. 2 DSUDDDSUDD (10ms duration), where different special subframe “S” configurations are possible such 1 5G frame structures provide a fixed overall structure for defining data block transmission timing. C. But in NR, the number of slots varies according to the numerology. There are total 10 subframes in a frame. Choose a configuration with more “D”s in the frame means greater proportion of Downlink Data (normal for most Internet /ISP applications) Tables defining Uplink Frame Structure; Frame Structure/Resource Grid; RU (Resource Unit) Tables defining Uplink Frame Structure . A frame has a duration of 10 ms and consists of 10 subframes. 211 frame structure type 2 (DL / UL / SSF) Correct choice of Configuration value is essential when setting the UL/DL ratio for CableFree LTE networks using TDD bands. Initial Cell Search and Cell Selection. IP packets are reformed in the PDCP SDUs and flow through the RLC, MAC, and PHY layers. (normal cyclic prefix) or six (extended cyclic prefix). The LTE standard uses Orthogonal Frequency Division Multiplexing (OFDM) modulation to achieve robust transmission in multipath scenarios (Liu et al. In LTE, DL and UL transmissions are organized into radio frames of 10 ms each. In LTE-Like structure, the reference signal is distribute over both time and frequency domain. 25KHZ, whereas UL Subcarrier=15KHz. Demodulating an LTE Signal in MATLAB with LTE System Toolbox. A typical LTE frame is 10 ms (milliseconds) long. 2 Physical Resources 12The LTE throughput optimization procedure described in this article requires PDCCH enhancements. g, LTE-U, LAA etc) refer to a technology in which LTE operates in 802. Figure 1. • Three PSS sequences are used in LTE, corresponding to the three physical layer identities within each group of cells. Each slot occupies either 7 symbols (for normal CP) and 6 symbols (for. 2. FDD is operated in the paired spectrum (see Sect. The frame can be dynamically configured to any one of the preset configurations shown, depending on the instantaneous data transmission requirement. 2. Now consider the details of a symbol. It consists of a 10 ms radio frame divided into 20 slots, each with a duration of 0. For example, S-CCPCH is transmitted at the multiples of 256 chips delay from the start of CPICH(Start of frame timing). LTE: Key Features (Cont) 8. I am happy to share the top articles of ShareTechNote in 2022 for 5G NR, 4G LTE and Engineering Math. 4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz. LTE defines a basic unit of time: In the time domain, both uplink and downlink are organized. ) Precoding Fading Power Control PUCCH. LTE devices remain unaffected (i. LTE tutorial- This tutorial on LTE covers LTE system overview, LTE air interface,LTE SAE and provide link for LTE Frame structure, LTE physical layer,LTE protocol stack,LTE terminologies,LTE advanced,LTE vendors etc. The LTE frame is formed of 10 subframes (SF) of duration 1 ms each and sub-divided into 14 OFDM symbols. The IP packet is enveloped in the 4G-LTE layers: 4G-LTE Packet Structure. Performance analysis of OFDMA in LTE. A frame has 10 subframes having 1ms duration each. Download scientific diagram | LTE frame structure used with FDD from publication: Experimental investigation on target detection and tracking in passive radar using long-term evolution signal. 3GPP LTE. 0 MHz, 10 MHz, 15 MHz, and 20 MHz. If you can interpret these tables into a correct graphical format, you already understand all the details of Uplink frame structure. Introduction The communication scenario in the world is growing at a large pace and the industry is gearing up for a thousand times more faster and reliable data rates. Type 2 LTE Frame Structure. They are LTE physical layer tutorials. 11 in order not to prevent the communiction between existing 802. · Radio frame size=. Slot Structure. The fre-quency index of an RE maps to an LTE subcarrier, and its time index maps to an LTE symbol. Uplink Frame Structure of LTE-NB can be summarized in the following three tables. It describes NB-IoT Frame Structure with 15 KHz Subcarrier spacing and 3. from publication: Analytical Link Performance Evaluation of LTE Downlink with Carrier Frequency Offset | In this paper, we evaluate the link. We will ignore the spatial domain for now and focus on the time-frequency plane. Hierarchy of Frame Structure : Frame (Radio Frame) --> SubFrame --> Slot (Same. The high-level network architecture of LTE is comprised of following three main components: The User Equipment (UE). 211 5. The Fading parameters are available for Advanced LTE and Advanced LTE-A TDD carriers only. In the LTE standard (E-UTRA Citation 2019), OFDM signals are specified by three parameters, namely, the number of subcarriers or the Fast Fourier. In TDD there are about 7 frame configurations, based on different DL/UL. divided into symbols – each slot has either 6 or 7 symbols. But there's plenty of work to do before the technical.