Difference between pdsch and pdcch. If UE successfully decoded the PDCCH, it decodes PDSCH carrying RAR data. This mapping information is further received by UEs in the form of PDSCH mapping type and PDCCH signals . In this case, UE used TCI specified in DCI 1_1. However, the MPDCCH has a few key differences that make it unique. 212 V13. The base station may have to schedule PDCCH and PDSCH separately, resulting in an increased scheduling complexity. 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. 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. downlink scheduling assignments and uplink scheduling grants. • Paging messages-These are broadcast using PDSCH channel. The table-2 below mentions coding rate for each DCI and PDCCH format. Mar 3, 2022 · According to 7. g. The precoding is transparent to the UE. If the UE finds the PDSCH, then based on the decoding result of the PDSCH, it sends feedback to the eNB/gNB (ACK/NACK). • Unlike LTE control channels which occupies entire system BW, 5G NR PDCCH channels occupy certain subcarriers and OFDM symbols. The NR system has added physical channels identical to LTE and physical channels for duplication in high-speed and high-frequency environments. 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). e. The modulation scheme for each PDSCH for each user is determined by MCS value in DCI. g, if DCI and PDSCH is in the same slot, k0 becomes 0) Jan 18, 2024 · 4. The messages sent by the PDCCH are called DCIs (downlink control indicator). It plays a crucial The PDCCH conveys encoded control information and scheduling decisions for PDSCH reception. it means. Basic Principle: PDCCH (Physical Downlink Control Channel): The PDCCH is a downlink control channel responsible for transmitting control information to UEs. The LTE network allocates these resources to ensure that UEs can reliably access PDSCH for user data and PDCCH for control information. PDSCH and PDCCH Transmission Process: 4. PDSCH with ≤ 4 layers uses only one codeword. e, DCI). Jan 1, 2022 · If PDCCH still maintains a cell-specific structure (as shown on the left in Fig. The location of the PDCCH is determined by CCE Index at transmitter (eNB). DMRS are shown in yellow. 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. 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. 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. In this paper, the characteristics of PDCCH physical channel in LTE and NR system are compared and the implementation of NR PDCCH is discussed. * PDSCH assignments to convey TB(s) to a certain UE, including time/frequency-domain resource information For example, Reference Signal, PDCCH, PDSCH etc. May 8, 2023 · The MPDCCH has a structure that is similar to the PDCCH. PDSCH (Physical Downlink Shared Channel) PDSCH is a physical channel that carries user data. One key difference between the MPDCCH and the PDCCH is the resource allocation. 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. 2-4. 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). The scrambling initialization of PDSCH corresponding to these PDCCHs is by C-RNTI. 2 Why is PDCCH required? 1. 4. 1. PDSCH with > 4 layers uses two codewords. Carrier. DMR for PBCH is spread across same bandwidth as used for PBCH (on same symbols). Scheduling of Jul 5, 2020 · 5G PDCCH is used to carry Downlink Control Information (DCI), and following types of DCI are supported in NR. 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. Carries user specific data (DL Payload). Each layer has 1/v the number of total modulation symbols. 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). 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. Apr 19, 2024 · The PDSCH FEC is similar to the PBCH and PDCCH (see this post). Refer LTE MIB and SIB page for MIB and SIB description. The time gap between PDSCH and corresponding Ack/Nack (k1) is determined by the combination of RRC Configuration and DCI. PDSCH is also used to transfer application data. Each PDCCH can take up 1, 2, 4 or 8 CCE's for link adaptation. The particular combination of design elements makes NR PDCCH unique compared to the PDCCH or EPDCCH designs in LTE. When I say 'communication' in this case, it means 'control command exchange' between UE and network, not the data traffic. 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. If a UE determines that a control resource set for Type0-PDCCH common search space is present, as described in Subclause 4. Carries Random Access Response Message in case of PDSCH mapped to RACH channel. 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. It implies this cannot be used when PDSCH start symbol is greater than 3. For determining time domain information of PDSCH we need few parameters like ‘k0’,’symbol start’ and ‘symbol length’. The research focuses on characterizing the behavior of the PDCCH channel concerning different User Equipment (UE) positions through simulations conducted in MATLAB. Blind Decoding and CRC Check: Jul 1, 2022 · PDCCH. PBCH, PDCCH, PDSCH, PUSCH and PUCCH. Format 6-1A . 1 What is PDCCH? 1. 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. Jan 18, 2024 · PDCCH (Physical Downlink Control Channel): 1. Some LTE transmission modes don't need PDSCH-DMRS since Cell-Specific Reference Signal (CRS) fulfils the role. PDCCH-ConfigCommon ::= SEQUENCE { controlResourceSetZero ControlResourceSetZero OPTIONAL, commonControlResourceSet ControlResourceSet OPTIONAL, -- Need R searchSpaceZero SearchSpaceZero OPTIONAL, -- Cond InitialBWP-Only commonSearchSpaceList SEQUENCE (SIZE(1. PUSCH - Enables or disables PUSCH auto-detection. A PDCCH is transmitted on one CCE or an aggregation of several consecutive CCEs, where a CCE corresponds to 9 Resource Element Groups (REGs). NSizeGrid = 51; % Bandwidth in number of resource blocks (51 RBs at 30 kHz SCS for 20 MHz BW) simParameters. Uplink. The main difference is that an \(r = 1/3\) Turbo code is used instead of an \(r = 1/3\) convolutional code. • The figure-1 depicts 5G NR PDCCH. 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. 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. 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. It plays a critical role in resource allocation, scheduling, and signaling for downlink data and uplink transmission. CSI-RS - Displays the On-Off status of each configured CSI-RS. The number of CCE's used for a PDCCH is termed aggregation level. 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). Time-Frequency Resource Allocation: Both PDSCH and PDCCH reference specific time-frequency resources in the LTE downlink. CRS, EPDCCH and EPDCCH-DMRS in LTE don't exist in 5G. LTE UE in RRC IDLE mode monitor PDCCH for paging indications. PDCCH Search Space refers to the area in the downlink resource grid where PDCCH may be carried. Two scenarios are Jan 18, 2024 · Let’s explore the details of PDCCH and DCI, highlighting their differences and roles in downlink communication. % Set waveform type and PDSCH numerology (SCS and CP type) simParameters. 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. 2 Mapping to physical resources paragraph of 3GPP TS 38. But this CCE index is not informed to the reciever (UE). This PDCCH and PDSCH should be carried in same subcarrier spacing and cyclic prefix as SIB1. Indicates the frequency domain offset between SSB and the overall resource block grid in number of subcarriers. Apr 25, 2023 · The main work of PDSCH is to perform slot-based mapping. See full list on rfwireless-world. ii) UE Monitor PDCCH. This is related to the row 'Type A' in PDSCH SLIV table. 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. TCI state for PDSCH = TCI state for CORESET/PDCCH. 213). The DCI bits have 16 bit CRC attached prior to rate-1/3 channel coding & rate matching modules. 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. iii) When gNB want to start PDSCH transmission, it sends DCI with CS-RNTI and start PDSCH transmission. PDCCH (Physical Downlink Control Channel): 1. For an overview of the available downlink control channel coding functionalities, see Downlink Control Information . Briefly speaking the whole FEC encoding process begins with a transport block, to which a CRC-24 is attached. Oct 17, 2019 · Resource Allocation Resource allocation in time domain. 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. to schedule Random Access Procedure initiated by a PDCCH Order; Followings are the summary of the DCI contents based on 36. 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. This takes a value of 1. 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. 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. Based on trigeer it will decode the paging message carried in PDSCH RBs. 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). coding rate = number of DCI bits after CRC attachment/Capacity of PDCCH. As the name implies, CORESET is a physical resources that is designed to transmit PDCCH/DCI. Case 2 : When tci-PresentInDCI = enabled. 3 What are i) gNB send RRC (RRCSetup or RRCReconfiguration) configuring all the parameters necessary for PDSCH scheduling. Figure 1 shows the downlink shared channel and “PDSCH transmit and receive processing chain”. In this case, UE used TCI state for CORESET/PDCCH as the TCI state for PDSCH. 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. Format 1_1. SubcarrierSpacing = 30; % 15, 30, 60, 120 (kHz) simParameters. 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. The UE needs to read the PDCCH first to find the location of the PDSCH. The rate matching algorithm also has a few small differences. It is using AMC with QPSK, 16 QAM and 64 QAM. If k_ssb requires the value higher than 15, it is represented by the combination of a PBCH data field and ssb-subcarrierOffset. Basic Principle: PDCCH (Physical Downlink Control Channel): PDCCH is a downlink control channel responsible for transmitting control information to user devices (UEs). Then you would have a question saying "How do we allocate power to each of the those channels ?". Auto Detection - Performs Power-based auto detection for the PUSCH physical channel. 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. 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 PDCCH carries scheduling assignments and other control information in the form of DCI messages. • PDCCH channel is used to carry DCI (Downlink Control Information) e. 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. 2-3 and 7. Oct 22, 2017 · Thank you for sharing this insightful article on LTE throughput optimization and the role of PDCCH enhancements in achieving it. 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. 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. 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. Out of every set of 72 resource elements where a PDCCH is mapped, 54 are for PDCCH and 18 are for associated DMRS. As DCI (Downlink Control Information) is carried by PDCCH, UCI is carried by PUCCH. • DMRS is UE specific which is transmitted on demand. 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. 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. 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. 36 RE's. Nov 14, 2022 · To understand the main difference between PDCCH and PDSCH BLER, we need to understand the concept of UE decoding. UE perform blind decoding throughout these search space trying to find PDCCH data (i. Carrier = nrCarrierConfig; % Carrier resource grid configuration simParameters. 38), there can be significant differences between PDCCH and PDSCH in terms of link performance, resource allocation, etc. Modulation Scheme is QPSK. 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. 3. Table-1 LTE PDCCH channel formats The PDCCH format is used as per required size of DCI. What it means: PDCCH and DMRS are transmitted using a single antenna port (2000). • DMRS is used to acquire PBCH, PDSCH etc. PDCCH - Displays the On-Off status of each configured PDCCH. 1-1: The location of a PDCCH that carries a DCI (even though it is the exactly identical information) varies at every subframe. 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. 0 (2016-06) - 5. 1-5. Higher aggregation levels allow for the transmission of more bits and support a higher number of UEs. 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. PUCCH is an uplink physical channel that carries UCI (Uplink Control Information). Multiple PDCCH are supported and a UE monitors a set of control channels. Configure CS for Uplink Feb 2, 2021 · PBCH-DMRS, PDCCH-DMRS, PUCCH-DMRS, PDSCH-PTRS and PUSCH-PTRS are new in 5G NR. 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. UE has to figure out the location of PDCCH by blind decoding. This is used for following purpose : to schedule PDSCH. 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). Following is the data structure of MAC PDU that carries RAR(Random Access Response) ssb-subcarrierOffset: This corresponds to k_ssb(38. This control information consists of uplink grants and PDSCH scheduling. 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. 211 Table 7. 5. At high level view, NR Search Space concept is similar to LTE Search Space, but there are many differences in terms of the details. different numerologies in DL and UL) •Use Case #2: Data/Synchronization CORESET stands for COntrol REsourceSET. 2. PDSCH - Displays the On-Off status of each configured PDSCH. 4. multiple FDM physical channels (e. uhdfapgwhotpgfqlnlelqigpehokfxemzytvdrlayibcvzcpn