Difference between pdsch and pdcch
Difference between pdsch and pdcch. If the UE finds the PDSCH, then based on the decoding result of the PDSCH, it sends feedback to the eNB/gNB (ACK/NACK). Sound simple ? On this view of the same frequency-time location, we also represent demodulation reference symbols or DMRS associated with the PDCCH in orange and the data channel or PDSCH in teal. The precoding is transparent to the UE. At high level view, NR Search Space concept is similar to LTE Search Space, but there are many differences in terms of the details. But this CCE index is not informed to the reciever (UE). Briefly speaking the whole FEC encoding process begins with a transport block, to which a CRC-24 is attached. A PDCCH is transmitted on one CCE or an aggregation of several consecutive CCEs, where a CCE corresponds to 9 Resource Element Groups (REGs). The messages sent by the PDCCH are called DCIs (downlink control indicator). The number of CCE's available for PDCCH depends on the size of • The design and mapping of DMRS is specific to each of the 5G physical channels viz. The rate matching algorithm also has a few small differences. 2 Mapping to physical resources paragraph of 3GPP TS 38. Scheduling of PDSCH in one cell DCI format 1_0 with CRC scrambled by C-RNTI DCI format 1_0 with CRC scrambled by C-RNTI for PDCCH Order DCI format 1_0 with CRC scrambled by RA-RNTI DCI format 1_0 with CRC scrambled by TC-RNTI DCI format 1_0 with CRC scrambled by SI-RNTI DCI format 1_0 with CRC scrambled by P-RNTI. This PDCCH and PDSCH should be carried in same subcarrier spacing and cyclic prefix as SIB1. The LTE network allocates these resources to ensure that UEs can reliably access PDSCH for user data and PDCCH for control information. Following is the data structure of MAC PDU that carries RAR(Random Access Response) ssb-subcarrierOffset: This corresponds to k_ssb(38. Carrier. This control information consists of uplink grants and PDSCH scheduling. • Unlike LTE control channels which occupies entire system BW, 5G NR PDCCH channels occupy certain subcarriers and OFDM symbols. If a UE determines that a control resource set for Type0-PDCCH common search space is present, as described in Subclause 4. coding rate = number of DCI bits after CRC attachment/Capacity of PDCCH. Refer LTE MIB and SIB page for MIB and SIB description. The PDCCH carries scheduling assignments and other control information in the form of DCI messages. The research focuses on characterizing the behavior of the PDCCH channel concerning different User Equipment (UE) positions through simulations conducted in MATLAB. LTE UE in RRC IDLE mode monitor PDCCH for paging indications. Configure CS for Uplink Feb 2, 2021 · PBCH-DMRS, PDCCH-DMRS, PUCCH-DMRS, PDSCH-PTRS and PUSCH-PTRS are new in 5G NR. Then you would have a question saying "How do we allocate power to each of the those channels ?". It is responsible for carrying DCI (Downlink Control Information), which informs UEs about the configuration of the PDSCH (Physical Downlink Shared While the full list of possible CCE aggregation levels is already defined in TS 38. Modulation Scheme is QPSK. After decoding RAR, UE checked if RAPID in RAR matches the RAPID assigned to the UE. In PDCCH transmission, only those REGs are used which are not assigned to PCFICH or PHICH. Case 2 : When tci-PresentInDCI = enabled. In this case, UE used TCI state for CORESET/PDCCH as the TCI state for PDSCH. • DMRS is UE specific which is transmitted on demand. 3. For determining time domain information of PDSCH we need few parameters like ‘k0’,’symbol start’ and ‘symbol length’. DMRS are shown in yellow. 5 m for the system with angle variation losses; DifgNBAlt UEAlt: The difference between the height of the gNB and the height of the UE; DisgNB UE: The distance that separates the gNB from the UE. UE has to figure out the location of PDCCH by blind decoding. . Feb 17, 2020 · To begin with, the topic let me tell you about what search space in PDCCH(Physical Downlink Control Channel is): Search Space is defined as a group of Control Channel Elements (CCEs) that This is a difference between NR and LTE) The time gap between PDSCH and corresponding Ack/Nack (k1) is not fixed any more (this is another difference between NR and LTE). PDCCH (Physical Downlink Control Channel): 1. e. In general, NR PDCCH provides the same functions as LTE PDCCH; however, Some new aspects related to PDCCH have been introduced in 5G, such as CORESET , which will be introduced in detail in the following sections. 1, the UE determines a number of consecutive resource blocks and a number of consecutive symbols for the control resource set of the Type0-PDCCH common search space from the four most significant bits of RMSI-PDCCH-Config May 8, 2023 · How the PDCCH Resources are being mapped from BTS Side, and What are the steps followed by the UE to deduce DCI information? Well, The below figure shows how the BTS is mapping all related Since ePDCCH is in the area where PDSCH is located and each ePDCCH is UE specific, we may apply BeamForming technology and it would increase the reliability of signal reception. If a UE is configured by higher layers to decode PDCCH with CRC scrambled by the C-RNTI, the UE shall decode the PDCCH and any corresponding PDSCH according to the respective combinations defined in table 7. See full list on rfwireless-world. 211 Table 7. This takes a value of 1. SubcarrierSpacing = 30; % 15, 30, 60, 120 (kHz) simParameters. Jan 18, 2024 · PDCCH (Physical Downlink Control Channel): 1. As the name implies, CORESET is a physical resources that is designed to transmit PDCCH/DCI. • The figure-1 depicts 5G NR PDCCH. • Paging messages-These are broadcast using PDSCH channel. Each PDCCH can take up 1, 2, 4 or 8 CCE's for link adaptation. Blind Decoding and CRC Check: Jul 1, 2022 · PDCCH. For an overview of the available downlink control channel coding functionalities, see Downlink Control Information . • PDCCH channel is used to carry DCI (Downlink Control Information) e. If UE successfully decoded the PDCCH, it decodes PDSCH carrying RAR data. % Set waveform type and PDSCH numerology (SCS and CP type) simParameters. While DCI on PDCCH is present in 5G, LTE's downlink controls CFI on PCFICH and HI on PHICH are absent How many CCEs are necessary to carry one PDCCH ? It depends on the format of the PDCCH. e, DCI). May 7, 2023 · Before going into the details of about 5G PDCCH, let’s first have a quick insight into the differences between 4G & 5G PDCCH. The NR system has added physical channels identical to LTE and physical channels for duplication in high-speed and high-frequency environments. ii) UE Monitor PDCCH. The DCI bits have 16 bit CRC attached prior to rate-1/3 channel coding & rate matching modules. Scheduling of Jul 5, 2020 · 5G PDCCH is used to carry Downlink Control Information (DCI), and following types of DCI are supported in NR. A big difference between DCI and UCI is that UCI can be carried either by PUCCH or PUSCH depending on situation whereas DCI can be carried only by PDCCH (not by PDSCH in any case). Table-1 LTE PDCCH channel formats The PDCCH format is used as per required size of DCI. 1-1: Supported PDCCH aggregation levels, for Type0, Type0A and Type2 PDCCH CSS, the CCE aggregation levels and the number of PDCCH candidates per CCE aggregation level are given in Table 10. Dec 4, 2023 · This article presents the implementation and the evaluation of a transmission–reception system for Physical Downlink Control Channel (PDCCH) within the context of fifth-generation cellular networks (5G/NR). PDCCH - Displays the On-Off status of each configured PDCCH. Indicates the frequency domain offset between SSB and the overall resource block grid in number of subcarriers. 0 (2016-06) - 5. May 8, 2023 · The MPDCCH has a structure that is similar to the PDCCH. different numerologies in DL and UL) •Use Case #2: Data/Synchronization CORESET stands for COntrol REsourceSET. The PDCCH plays a crucial role in resource allocation, scheduling, and coordination between the base station and UEs, facilitating efficient data transmission in Case 1: When tci-PresentInDCI = omit or PDSCH is scheduled by DCI 1_0. This type is used for slot The mapping of PDCCH is based on a conception of control channel element (CCE), which is essentially a simple representation of 9 REG's, i. 5. NSizeGrid = 51; % Bandwidth in number of resource blocks (51 RBs at 30 kHz SCS for 20 MHz BW) simParameters. PDSCH with > 4 layers uses two codewords. PBCH, PDCCH, PDSCH, PUSCH and PUCCH. Out of every set of 72 resource elements where a PDCCH is mapped, 54 are for PDCCH and 18 are for associated DMRS. PDSCH is also used to transfer application data. PDSCH and PDCCH Transmission Process: 4. PDCCH-ConfigCommon ::= SEQUENCE { controlResourceSetZero ControlResourceSetZero OPTIONAL, commonControlResourceSet ControlResourceSet OPTIONAL, -- Need R searchSpaceZero SearchSpaceZero OPTIONAL, -- Cond InitialBWP-Only commonSearchSpaceList SEQUENCE (SIZE(1. 4)) OF SearchSpace OPTIONAL, searchSpaceSIB1 SearchSpaceId OPTIONAL, -- Need S Dec 7, 2023 · In 5G NR (New Radio), the Physical Downlink Control Channel (PDCCH) plays a critical role in the control of downlink resource allocations, scheduling, and signaling for UEs (User Equipment). DMR for PBCH is spread across same bandwidth as used for PBCH (on same symbols). 4. PUCCH is an uplink physical channel that carries UCI (Uplink Control Information). Apr 25, 2023 · The main work of PDSCH is to perform slot-based mapping. TCI state for PDSCH = TCI state for CORESET/PDCCH. * PDSCH assignments to convey TB(s) to a certain UE, including time/frequency-domain resource information For example, Reference Signal, PDCCH, PDSCH etc. It implies this cannot be used when PDSCH start symbol is greater than 3. 1-5. For any additional DM-RS, the duration of OFDM symbols (l d) is the number of OFDM symbols between the first OFDM symbol of the slot (symbol #0) and the last OFDM symbol of the allocated PDSCH resources. Can we complete remove the CFI overhead ? If we can move the PDCCH data to PDSCH area, can we completely remove the overhead caused by the symbol 0 (or 1,2) ? PDSCH mapping type changes the location pattern in time domain; PDSCH Mapping Type A : In this type, the DMRS symbol can start only at symbol 2 or 3 regardless of PDSCH start and length. UE perform blind decoding throughout these search space trying to find PDCCH data (i. 2-3 and 7. Uplink. The UE needs to read the PDCCH first to find the location of the PDSCH. It is using AMC with QPSK, 16 QAM and 64 QAM. Carries Random Access Response Message in case of PDSCH mapped to RACH channel. The main difference is that an \(r = 1/3\) Turbo code is used instead of an \(r = 1/3\) convolutional code. Basic Principle: PDCCH (Physical Downlink Control Channel): The PDCCH is a downlink control channel responsible for transmitting control information to UEs. This mapping information is further received by UEs in the form of PDSCH mapping type and PDCCH signals . Oct 17, 2019 · Resource Allocation Resource allocation in time domain. The number of CCE's used for a PDCCH is termed aggregation level. 3GPP hasn't specified the precoding for PDCCH but base station can apply precoding to this antenna port to generate a beam in the direction of the UE. The time gap between PDSCH and corresponding Ack/Nack (k1) is determined by the combination of RRC Configuration and DCI. The location of the PDCCH is determined by CCE Index at transmitter (eNB). PDSCH DMRS is Type A; The DMRS location is fixed to 3rd (pos2) or 4th(pos3) PDSCH Starting Symbol can be 0~3; PDSCH Length can be 3~14 in case of normal CP and 3~12 in case of extended CP; the DMRS symbol can start only at symbol 2 or 3 regardless of PDSCH start and length. The table-2 below mentions coding rate for each DCI and PDCCH format. This is related to the row 'Type A' in PDSCH SLIV table. 38), there can be significant differences between PDCCH and PDSCH in terms of link performance, resource allocation, etc. The MPDCCH is transmitted on the same frequency and time resources as the PDCCH, and it uses the same modulation and coding schemes as the PDCCH. Based on trigeer it will decode the paging message carried in PDSCH RBs. If k_ssb requires the value higher than 15, it is represented by the combination of a PBCH data field and ssb-subcarrierOffset. com Dec 7, 2023 · PDCCH supports different aggregation levels, indicating the number of consecutive CCEs (Control Channel Elements) that are aggregated to form a PDCCH transmission. Codeword 0 maps onto the first ⌊v / 2⌋ layers, with size of ⌊v / 2⌋Mlayer symb; Codeword 1 maps onto the last ⌈v / 2⌉ layers, with size of ⌈v / 2⌉Mlayer symb. Most important parameters related to Resource Allocation in Time Domain and Ack/Nack responses are : k0, k1, k2, SLIV, N1, N2; k0 indicates the number of time slot between PDCCH/DCI and Downlink Data(PDSCH) transmission (e. PDSCH - Displays the On-Off status of each configured PDSCH. Multiple PDCCH are supported and a UE monitors a set of control channels. The relationship between PDCCH format and the number CCE required to carry the PDCCH is as follows : PDCCH Format 0 : Requires 1 CCE = Aggregation Level 1 (2^PDCCH Format = 2^0 = 1) PDCCH Format 1 : Requires 2 CCE = Aggregation Level 2 (2^PDCCH Format = 2^1 = 2) an initial DL BWP is defined by a location and number of contiguous PRBs, starting from a PRB with the lowest index and ending at a PRB with the highest index among PRBs of a CORESET for Type0-PDCCH CSS set, and a SCS and a cyclic prefix for PDCCH reception in the CORESET for Type0-PDCCH CSS set ==> It mean that the initialDlBWP takes up the Feb 12, 2020 · PDCCH is the heart of the data call, if the UE is unable to decode and get the DCI info carried in the PDCCH, then no matter what the radio conditions are UE can never know the DL/UL grants for Jun 7, 2019 · Learn about downlink control information, or DCI, in 5G New Radio. Carrier = nrCarrierConfig; % Carrier resource grid configuration simParameters. PUSCH - Enables or disables PUSCH auto-detection. The video walks you through the different types of messages, including downlink assignment and uplink grant, and how they are encoded and modulated and then mapped to the 5G New Radio slot via the PDCCH or physical downlink control channel. CSI-RS - Displays the On-Off status of each configured CSI-RS. for PDSCH mapping type A, l d is the duration between the first OFDM symbol of the slot and the last OFDM symbol of the scheduled PDSCH resources in the slot; for PDSCH mapping type B, l d is the duration of the scheduled PDSCH resources; and according to Tables 7. However, the MPDCCH has a few key differences that make it unique. One key difference between the MPDCCH and the PDCCH is the resource allocation. What it means: PDCCH and DMRS are transmitted using a single antenna port (2000). Time-Frequency Resource Allocation: Both PDSCH and PDCCH reference specific time-frequency resources in the LTE downlink. Format 6-1A . The breakdown of PDCCH structure and its aggregation layers provided a clear understanding of how scheduling allocations work for PDSCH and PUSCH, making it easier to comprehend the overall optimization process. Mar 3, 2022 · According to 7. In this paper, the characteristics of PDCCH physical channel in LTE and NR system are compared and the implementation of NR PDCCH is discussed. Oct 22, 2017 · Thank you for sharing this insightful article on LTE throughput optimization and the role of PDCCH enhancements in achieving it. it means. CRS, EPDCCH and EPDCCH-DMRS in LTE don't exist in 5G. 213). multiple FDM physical channels (e. Jan 1, 2022 · If PDCCH still maintains a cell-specific structure (as shown on the left in Fig. 211 Physical channels and modulation, for PDSCH mapping type A, l "d" is the duration between the first OFDM symbol of What do you learn after watching this video?2 Main Things - 1 Introduction of PDCCH 1. 2. g, if DCI and PDSCH is in the same slot, k0 becomes 0) Jan 18, 2024 · 4. • DMRS is used to acquire PBCH, PDSCH etc. Carries user specific data (DL Payload). PDCCH (Physical Downlink Control Channel) As in LTE, NR PDCCH is the physical channel that carries DCI and this would be one of the most important channel which is supposed to be very robust and easily decoded even in harsh radio condition. PDCCH is like HS-SCCH for HSDPA and PDCCH for R99, E-AGCH/E-RGCH for HSUPA; Even though PDCCH has a lot of functions, not all of them are used at the same time so PDCCH configuration should be done flexibly. Apr 19, 2024 · The PDSCH FEC is similar to the PBCH and PDCCH (see this post). Nov 14, 2022 · To understand the main difference between PDCCH and PDSCH BLER, we need to understand the concept of UE decoding. 36 RE's. Dec 4, 2023 · gNBAlt: The height of the gNB, which varies between 10 and 150 m; UEAlt: The height of the UE, can take values from 1 to 10 m. Format 1_1. Two scenarios are Jan 18, 2024 · Let’s explore the details of PDCCH and DCI, highlighting their differences and roles in downlink communication. In UMTS case, it is true that only RRC and NAS message functions as communication between UE and Network, but in LTE and NR a special type of communication is introduced working at MAC Layer. It plays a crucial The PDCCH conveys encoded control information and scheduling decisions for PDSCH reception. iii) When gNB want to start PDSCH transmission, it sends DCI with CS-RNTI and start PDSCH transmission. Basic Principle: PDCCH (Physical Downlink Control Channel): PDCCH is a downlink control channel responsible for transmitting control information to user devices (UEs). 1. It corresponds to control region in LTE subframe, but the difference is that frequency domain resource allocation in 5G Coreset is configurable whereas in LTE the contron region always takes up the full channel bandwidth. 12 Jul 11, 2018 · This paper analyzes physical downlink control channel (PDCCH) for 5G New Radio (NR) technology defined as part of Rel-15 3GPP physical layer specifications. CyclicPrefix = 'Normal'; % 'Normal' or 'Extended May 29, 2023 · The primary objective of the PDCCH is to convey control information that enables UEs to effectively receive and decode data transmitted on the Physical Downlink Shared Channel (PDSCH). PDSCH with ≤ 4 layers uses only one codeword. 212 V13. As DCI (Downlink Control Information) is carried by PDCCH, UCI is carried by PUCCH. Auto Detection - Performs Power-based auto detection for the PUSCH physical channel. 2-4. PDSCH, PDCCH, PUSCH, PUCCH) with different numerologies at the same time – Two FDM use cases •Use Case #1: Data/Data - Not supported in DL (for Rel-15) - Not supported in UL (for Rel-15) - Supported between DL and UL (i. The base station may have to schedule PDCCH and PDSCH separately, resulting in an increased scheduling complexity. The simplest way for our understanding would be to allocate the same power to all of the these channels, but this would be only for the sake of our understanding. PDCCH Search Space refers to the area in the downlink resource grid where PDCCH may be carried. 2 Why is PDCCH required? 1. 4. Figure 1 shows the downlink shared channel and “PDSCH transmit and receive processing chain”. The particular combination of design elements makes NR PDCCH unique compared to the PDCCH or EPDCCH designs in LTE. Higher aggregation levels allow for the transmission of more bits and support a higher number of UEs. g. 1-1: The location of a PDCCH that carries a DCI (even though it is the exactly identical information) varies at every subframe. The scrambling initialization of PDSCH corresponding to these PDCCHs is by C-RNTI. The modulation scheme for each PDSCH for each user is determined by MCS value in DCI. When I say 'communication' in this case, it means 'control command exchange' between UE and network, not the data traffic. PDSCH (Physical Downlink Shared Channel) PDSCH is a physical channel that carries user data. Some LTE transmission modes don't need PDSCH-DMRS since Cell-Specific Reference Signal (CRS) fulfils the role. This is used for following purpose : to schedule PDSCH. 3 What are i) gNB send RRC (RRCSetup or RRCReconfiguration) configuring all the parameters necessary for PDSCH scheduling. The PDCCH, or physical downlink control channel, is used to transmit all the control information that is not carried by any of the other channels (PBCH, PCFICH, PHICH). Each layer has 1/v the number of total modulation symbols. In this case, UE used TCI specified in DCI 1_1. It plays a critical role in resource allocation, scheduling, and signaling for downlink data and uplink transmission. to schedule Random Access Procedure initiated by a PDCCH Order; Followings are the summary of the DCI contents based on 36. We focus on the physical aspects of NR PDCCH structure and provide an in-depth summary of the design considerations The 5G NR system starts with Release 15 and includes Release 16. downlink scheduling assignments and uplink scheduling grants. 1 What is PDCCH? 1. Note that l d may differ from the number of OFDM symbols allocated for PDSCH, when the first OFDM symbol of PDSCH is other than symbol #0. ohl nizgxx imfye yjjgs ossgw ponafl anu igqkhwh vvk dikqbxlq