Type 1 radio frame has a duration 10 ms and consists of equally. Structure that are used in lte where both transmitter and receiver. Labview communications lte application framework 2. Physical layer frame structure in 4g lteltea downlink.
Lte tdd special subframe and its significance for cell. The frame structure for the type 2 frames used on lte tdd is somewhat different. Each radio frame of length 10 ms t frame 307, 200 t s comprises two halfframes, where each half frame consists of five subframes of length 1 ms. Frame structure type 2 is applied to a tdd duplex scheme where the downlink and uplink transmissions are timemultiplexed over the extent of a radio frame figure 9. There are two types of frame structure in the lte standard, type 1 and type 2. Downlinkuplink ratio can vary from frame configuration 0 to 81 frame configuration 1. Downlink and uplink transmission an overview sciencedirect. Nr allows one common frame structure over both paired and. It is an acronym for evolved universal mobile telecommunications system terrestrial radio access, also referred to as the 3gpp work item on the long term evolution lte also known as the evolved universal terrestrial radio access eutra in early drafts of the 3gpp. Lte fdd systems use frame structure type 1, where radio frames are divided into subframes, times slots, and eventually symbols. Other than this distinction, lte tdd had little, if anything, in common with earlier timedivisionduplexing. Even though the name still remain as ltesomething, ltenb is pretty new design from the very bottom physical layer. Tdd mode, based on frame structure 2, further optimizing.
Lte downlink frame structure long term evolution 4g. Lte a frame structure free download as powerpoint presentation. The figure below shows the lte frame structure under time division mode tdd type 2 and frequency division mode fdd type 1. The lte application framework implements parts of a 3gpp lte release 10 compliant dl and ul phy tx and rx. This is then divided into a total of 20 individual slots. Lte fdd uplink frame structure as in downlink, frame time and slot time in uplink is the same as in the downlink.
Ltenb frame structure can be summarized as follows. The radio frame is represented in the lte toolbox product by the use of a succession of 10 cellwide settings structures with the nsubframe field set from 0 through 9 in each case. This example shows how to create a frame containing the cellspecific reference signals cellrs in each subframe. The remaining six symbols have a cyclic prefix of length tcp 144. Lte frame structure based on peak to average power ratio.
The type of subframe, whether it is a downlink, uplink or a special subframe depends on the type of duplexing, whether fdd or tdd. The lte halfframes are further split into five sub frames, each 1ms long. In fdd mode, this is done using frame structure type 1. Ltea frame structure radio technology software defined radio. The detailed radio frame structure for both frame structure types is shown in. Hence lte radio frame will have duration of about 10ms. This is the same as in lte, facilitating nr and lte coexistence. A frame has a duration of 10 ms and consists of 10 subframes. Jul 18, 2014 type 1 lte frame structure the basic type 1 lte frame has an overall length of 10 ms. M p actually, there is 25% overhead in lte hence we have.
Apr 18, 2018 the frame structures for lte differ between the time division duplex, tdd and the frequency division duplex, fdd modes as there are different requirements on segregating the transmitted data. But as we see more diverse types of subframe structure fdd frame structure type1, tdd frame structure type 2, laa frame structure type 3, i see my confidence gets weaker. In comparison with lte for frame synchronization in nr it is necessary to. Frame 0 and frame 5 always downlink in tdd frame 1 and frame 6 is always used as for. This video explains the lte technology basics, ofdma and lte frame structures and types. Pillai3 1,2,3department of electronics and communication engineering, mar baselios college of engineering and technology, trivandrum, india. Performance analysis of scfdma and ofdma in lte frame. Two types of radio frame structures are designed for lte. In tdd there are about 7 frame configurations, based on different dlul partition. But anyway good thing to me was that the most important factors in uplink slot is same as the one in the downlink. Physical layer frame structure in 4g lte lte a downlink based on lte system toolbox sherry varghese george1, luxy mathews2, sakuntala s.
Although a slot is a typical unit for transmission upon which scheduling operates, nr enables transmission to. Fundamentals of rf sigal analyzers introduction to lte device. For the beginners, there is always a confusion about the frame structure, the physical channels etc, so to make their job easy, i am writing this article. Jul 27, 20 this video explains the lte technology basics, ofdma and lte frame structures and types. Consequently, lte, which was originally designed with fixed fdd or tdd modes with little flexibility for varying the capacity split between uplink and downlink, is being augmented with features that allow for more flexible use of radio resources. Frame structure type 2 is applied to a tdd duplex scheme where the downlink and.
Explain lte frame structure both for fdd and tdd techplayon. A radioframe is the largest unit of the lte frame structure, its duration is 10 milliseconds and it consists of 10 subframes each of length 1 milliseconds. To start with, what does the downlink frame structure consists of. Physical layer frame structure in 4g lteltea downlink based on lte system toolbox sherry varghese george1, luxy mathews2, sakuntala s. Each subframe consists of 2 slots of 14 ofdm symbols each. Here we present information, overview, or tutorial about the lte frame and subframe structure including lte type 1 and lte type 2 frames. Frame structure type 1 twenty time slots in a frame, each 0. Release 8 and release 9 architecture, access technique and frame structure, physical layer lte advanced. Implementation of the physical random access channel in tdd. Frequency division duplexing fdd and time division duplexing tdd both paired and unpaired. Key differences between the physical layers of lte and nr. Frame structure type 2for 5ms switchpoint periodicity figure 22. But as we see more diverse types of subframe structure fddframe structure type1, tdd frame structure type 2, laa. Downlink subframe an overview sciencedirect topics.
The 10 ms frame comprises two half frames, each 5 ms long. As mentioned as per topologies, tdd and fdd there are two frame structures viz. Operation in unlicensed spectrum is dependent on several key principles including ultralean transmission and use of the flexible nr frame structure. Jun 03, 20 for the beginners, there is always a confusion about the frame structure, the physical channels etc, so to make their job easy, i am writing this article. Eutra is the air interface of 3rd generation partnership project long term evolution lte upgrade path for mobile networks. Lte tdd special subframe and its significance for cell size. To keep the complexity of this application framework at a reasonably low level, only a subset of the physical layer features defined for 3gpp lte release 10 compliant devices is implemented. In the time domain, lte transmissions are organized into frames of length 10 ms, each of which is. The presentations are accompanied with an audio narration. Refer article lte physical downlink channels for more. Manual labview communications lte application framework 2.
Different frame structures are used in lte for fdd and tdd modes. Lte etsi 650 route des lucioles f06921 sophia antipolis cedex france. Each radio frame of length 10 ms t frame 307, 200 t s comprises two halfframes, where. One lte lb and two conjoined lte mhb mimo antennas with a. Fundamentals of network planning and optimisation 2g3g4g. A subset of the downlink subframes in a radio frame on a carrier. In lte the bits are stored into symbols and slots and transmitted through frames over the rf link. Type 1 lte frame structure the basic type 1 lte frame has an overall length of 10 ms. This is the 5thmodule in a series of lectures on 2g3g, lte, lteadvanced 4g, lteadvanced pro 4. Lte frame structure and resource block architecture. During the early development stages of lte, lte tdd had two frame structure options, including one frame structure that was very similar to the frame structure used by tdscdma or lcr tdd, as it is referred to in the 3gpp specifications. The frame structures for lte differ between the time division duplex, tdd and the frequency division duplex, fdd modes as there are different requirements on segregating the transmitted data. That is, frame 2 not only functions as a radiator of the second antenna but also serves as a decoupling structure to attract the surface currents on the system ground plane which causes.
Main differences in lte frame structure between the two modes are. The lte halfframes are further split into five subframes, each 1ms long. Lte basics part i ofdma and lte frame structures youtube. In case of dispute, the reference shall be the printing on etsi printers of the pdf version kept on a specific network drive. As shown in the figure below, an lte tdd frame is made of total 20 slots, each of 0. Two slots make one subframe, which is 1ms long 30,720 t s. Physical layer frame structure in 4g lteltea downlink based. Introduction to lte raj jain washington university in saint louis saint louis, mo 63.
Nov 25, 2015 frame structure in lte fdd downlink frame structure in lte. For the normal mode, the first symbol has a cyclic prefix of length tcp 160. This greatly adds to deployment flexibility compared with lte, where only licensedassisted operation is supported. The subframes may be divided into standard subframes of. Lte subframes then consist of two slots in other words there are ten lte subframes within a frame. This is the 5thmodule in a series of lectures on 2g3g, lte, lte advanced 4g, lte advanced pro 4.
Aug 01, 2017 a tdd frame structure is shown in below figure. Just take a look at the overall uplink slot structure. Lte uses both frequency division duplex fdd and time division. A radio frame is the largest unit of the lte frame structure, its duration is 10 milliseconds and it consists of 10 subframes each of length 1 milliseconds. The biggest difference of any new wireless communication technology starts from physical layer frame structure. In eutra frame structure, each downlink subframe and the dwpts fields in the case of tdd is divided into a control region, consisting of the first ofdm symbols of the subframe, and a data region, comprising the remaining ofdm symbols of the subframe. Ltea frame structure free download as powerpoint presentation. The lte application framework is available with labview communications system design suite. Each radio frame is of duration 10ms and composed of 15 slots. Number of downlink to uplink switch points within the radio frame. Wideband decoupling between the 2 antennas for the 2.