This document summarizes research on the uplink control channel design for 3GPP LTE. It discusses the uplink structure using Single-Carrier Frequency Division Multiple Access (SC-FDMA) and the uplink control signaling design. The control signaling includes Channel Quality Information (CQI), ACK/NACK, and Scheduling Requests. The paper describes how these different control signals are multiplexed and transmitted in the uplink to maintain the single carrier property while supporting multiple users. Performance results are presented to evaluate the design and coding schemes for the CQI and ACK/NACK channels.
Multi-layer heterogeneous network layout including small cell base stations are considered to be the key to further enhancements of the spectral efficiency achieved in mobile communication networks. It has been recognized that inter-cell interference has become the limiting factor when trying to achieve not only high average user satisfaction, but a high degree of satisfaction for as many users as possible. Therefore, inter-cell interference coordination (ICIC) lies in the focus of researchers defining next generation mobile communication standards, such as LTE-A.
Building upon [1], this paper provides an overview over the background calling for ICIC in heterogeneous LTE-A networks. It outlines techniques standardized in Rel. 10 of LTE-A, discusses them showing their benefits and limitations by means of system-level simulations and motivates the importance of self optimizing network (SON) procedures for ICIC in LTE-A.
This presentation covers:
1. Evolution of UMTS core network
2. Different 3GPP releases up gradation to UMTS architecture
3. UMTS Core network elements
4. Protocols used in UMTS core networks
5. MSC server and MGW
6. IMS architecture
Heterogeneous LTE Networks and Inter-Cell Interference Coordination - Dec 201...Eiko Seidel
This document discusses heterogeneous LTE networks and inter-cell interference coordination (ICIC). It begins by explaining that initial LTE networks consisted of homogeneous macro cell deployments but that heterogeneous networks using smaller pico and femto cells are now being implemented to improve capacity and coverage. This introduces new interference challenges. The document then outlines various ICIC methods like frequency reuse and power control techniques that can help mitigate interference. It provides simulation results showing the benefits of heterogeneous networks and techniques like range expansion.
Some of the key driving forces behind the transition from the UMTS based cellular system to the Long Term Evolution Advanced (LTE-A) are to improve the mean and the cell-edge throughput, improve the user fairness, and improve the quality of service (QoS) satisfaction for all users. In the latter system, relays appear as one of the most prominent enabler for improving the cell-edge user experience while increasing the system’s fairness.
In this white paper, we present the basics of relay deployments in LTE-A networks. Moreover, we analyze resource allocation problem for Relay Nodes (RN) deployments and present some of the solutions for improvement in system resource usage and QoS satisfaction. Afterwards, we introduce the capabilities of NOMOR’s LTE-A system level simulator and evaluate the performance of LTE-A relay systems under the described solutions.
This presentation covers:
How evolution has happened from First Generation Mobile Communication Systems to present day 3G/UMTS/WCMDA systems
Brief introduction of each Generation: GSM - 2G, 2.5 G - GPRS, 2.75G - EDGE, 3G and then LTE/4G
This document provides an introduction to UMTS (Universal Mobile Telecommunications System). It describes the context and limitations of previous mobile systems that led to the development of 3G systems like UMTS. The goals of UMTS are to provide high-quality wireless multimedia services across converged fixed and mobile networks. The technical overview explains that UMTS uses CDMA to separate users within a cell and has both FDD and TDD duplex modes for frequency division.
UMTS system architecture, protocols & processesMuxi ESL
This document provides an overview of UMTS system architecture and protocols. It discusses:
- The logical architecture of UTRAN including RNC and Node-B elements.
- Interfaces between network elements are clearly specified to allow interoperability between equipment from different manufacturers.
- The main functions of the RNC include radio resource management, call management, and connection to the core network.
- Protocols in UTRAN include RRC for radio resource control, RLC for radio link control, and MAC for medium access control.
Multi-layer heterogeneous network layout including small cell base stations are considered to be the key to further enhancements of the spectral efficiency achieved in mobile communication networks. It has been recognized that inter-cell interference has become the limiting factor when trying to achieve not only high average user satisfaction, but a high degree of satisfaction for as many users as possible. Therefore, inter-cell interference coordination (ICIC) lies in the focus of researchers defining next generation mobile communication standards, such as LTE-A.
Building upon [1], this paper provides an overview over the background calling for ICIC in heterogeneous LTE-A networks. It outlines techniques standardized in Rel. 10 of LTE-A, discusses them showing their benefits and limitations by means of system-level simulations and motivates the importance of self optimizing network (SON) procedures for ICIC in LTE-A.
This presentation covers:
1. Evolution of UMTS core network
2. Different 3GPP releases up gradation to UMTS architecture
3. UMTS Core network elements
4. Protocols used in UMTS core networks
5. MSC server and MGW
6. IMS architecture
Heterogeneous LTE Networks and Inter-Cell Interference Coordination - Dec 201...Eiko Seidel
This document discusses heterogeneous LTE networks and inter-cell interference coordination (ICIC). It begins by explaining that initial LTE networks consisted of homogeneous macro cell deployments but that heterogeneous networks using smaller pico and femto cells are now being implemented to improve capacity and coverage. This introduces new interference challenges. The document then outlines various ICIC methods like frequency reuse and power control techniques that can help mitigate interference. It provides simulation results showing the benefits of heterogeneous networks and techniques like range expansion.
Some of the key driving forces behind the transition from the UMTS based cellular system to the Long Term Evolution Advanced (LTE-A) are to improve the mean and the cell-edge throughput, improve the user fairness, and improve the quality of service (QoS) satisfaction for all users. In the latter system, relays appear as one of the most prominent enabler for improving the cell-edge user experience while increasing the system’s fairness.
In this white paper, we present the basics of relay deployments in LTE-A networks. Moreover, we analyze resource allocation problem for Relay Nodes (RN) deployments and present some of the solutions for improvement in system resource usage and QoS satisfaction. Afterwards, we introduce the capabilities of NOMOR’s LTE-A system level simulator and evaluate the performance of LTE-A relay systems under the described solutions.
This presentation covers:
How evolution has happened from First Generation Mobile Communication Systems to present day 3G/UMTS/WCMDA systems
Brief introduction of each Generation: GSM - 2G, 2.5 G - GPRS, 2.75G - EDGE, 3G and then LTE/4G
This document provides an introduction to UMTS (Universal Mobile Telecommunications System). It describes the context and limitations of previous mobile systems that led to the development of 3G systems like UMTS. The goals of UMTS are to provide high-quality wireless multimedia services across converged fixed and mobile networks. The technical overview explains that UMTS uses CDMA to separate users within a cell and has both FDD and TDD duplex modes for frequency division.
UMTS system architecture, protocols & processesMuxi ESL
This document provides an overview of UMTS system architecture and protocols. It discusses:
- The logical architecture of UTRAN including RNC and Node-B elements.
- Interfaces between network elements are clearly specified to allow interoperability between equipment from different manufacturers.
- The main functions of the RNC include radio resource management, call management, and connection to the core network.
- Protocols in UTRAN include RRC for radio resource control, RLC for radio link control, and MAC for medium access control.
This document provides an introduction to LTE/E-UTRA technology, including both FDD and TDD modes of operation. It describes the key requirements for UMTS Long Term Evolution such as high data rates, low latency, and improved spectrum efficiency compared to previous standards. The document then covers various aspects of the LTE standard, including the OFDMA downlink and SC-FDMA uplink transmission schemes, MIMO concepts, protocol architecture, UE capabilities, and testing considerations. Abbreviations used and additional references are also provided.
This document provides an overview of UMTS W-CDMA (Universal Mobile Telecommunications System Wideband Code Division Multiple Access). It describes the basic architecture and channel structures of a 3G W-CDMA system. Key points include that W-CDMA uses CDMA technology with a chip rate of 3.84 Mcps and channel bandwidth of 4.4-5 MHz. It also discusses the various physical channels in the uplink and downlink, including dedicated channels, common channels, and how they are structured over timeslots and frames.
The document provides an overview of the Long Term Evolution (LTE) mobile telecommunication system. It discusses the evolution of mobile standards leading to LTE and describes key requirements for LTE including increased data rates, reduced latency, improved spectral efficiency, and seamless mobility. Performance targets for LTE are outlined for downlink and uplink peak transmission rates, spectral efficiencies, and latency. LTE is designed to support high speed mobility up to 350 km/h and interoperate with other radio access technologies.
Maria D'cruz_WCDMA UMTS Wireless NetworksMaria D'cruz
The document provides an overview of WCDMA/UMTS architecture and radio resource management. It describes the evolution from 2G to 3G networks and the standardization of WCDMA. The key aspects of WCDMA air interface, UTRAN architecture, core network functionality, and radio resource management techniques like admission control, load control, packet scheduling, handover control and power control are summarized. Diagrams illustrate the system architecture and information flow between network elements.
This document provides an overview of the LTE radio layer 2, radio resource control (RRC), and radio access network architecture. It discusses the E-UTRAN architecture including eNodeBs, home eNodeBs, and relays. It describes the user plane including bearer services, the user plane protocol stack with PDCP, RLC, and MAC layers, and security and transport functions. It also outlines the control plane including connection control and RRC states, and highlights features like interoperability, self-organizing networks, positioning, broadcasting, latency evaluations, and LTE-Advanced.
This document summarizes a research paper that implemented SC-FDMA and OFDMA in MATLAB to evaluate the performance of the LTE physical layer. It provided background on LTE standards and an overview of the key aspects of LTE systems, including frame structure, bandwidth allocation, modulation schemes, and multiple access techniques. The document also reviewed literature on the LTE physical layer design and described how time and frequency resources are divided in LTE.
Overview of LTE Air-Interface Technical White PaperGoing LTE
1) The document discusses Long Term Evolution (LTE), a planned evolution of the 3G UMTS mobile communications standard to improve speed and capacity.
2) It provides an overview of the new LTE E-UTRA air interface, including performance requirements, key technologies like OFDM for downlink and SC-FDMA for uplink, frame structure, and control channel design.
3) Initial system simulations show LTE can provide 2-3x the throughput of existing 3G systems for both uplink and downlink.
TETRA is a trunked radio standard used in public safety networks. It allows for fast call setup, voice and data services, and operates in both infrastructure and ad-hoc modes. UMTS is the 3G cellular standard developed by ETSI for wide-area mobile communication. It uses W-CDMA technology and supports high data rates through variable spreading factors and orthogonal codes. UMTS has an architecture with domains for the user equipment, access network, core network and home network connected by defined interfaces.
This document discusses the key interfaces, architecture, and procedures related to control and user planes, mobility management, and connection management in 3G networks. The control plane handles protocols for controlling radio access bearers and the connection between UE and network. It has physical, data link, and network layers. The user plane is responsible for transferring user data through access and core network protocols. Mobility management allows tracking and delivering services to mobile subscribers via location management, registration, and security functions. Connection management establishes and maintains connections to exchange information with peer entities.
UMTS-WCDMA is a 3G mobile communication standard that uses CDMA technology. It uses wideband CDMA with a chip rate of 3.84 Mcps for its air interface along with orthogonal variable spreading factor codes. The standard defines protocols and procedures for cell search, handover, uplink and downlink physical channels, and support for multirate services through variable spreading factors. Long term targets for UMTS-WCDMA evolution include higher data rates up to 100 Mbps for full mobility and 1 Gbps for low mobility, as well as improved spectral efficiency.
The document provides an overview of advanced wireless networks and UMTS. It discusses the evolution from 2G to 3G networks, including the limitations of 2G and requirements for 3G. It describes the UMTS architecture, including the UTRAN, core network, and protocols on the Iu interface. It also covers basic UMTS principles such as CDMA techniques, radio resources including frequency, time, and power/code, and radio resource management.
Umts Radio Interface System Planning And OptimizationDavid Rottmayer
The document discusses planning and optimizing UMTS radio networks. It begins with an overview of UMTS network architecture and the differences between UMTS and GSM radio system planning. Key aspects of UMTS planning include coverage and capacity planning occurring simultaneously, as capacity requirements influence coverage. The document then covers WCDMA air interface specifications, propagation environments, and the UMTS radio system planning process. It discusses challenges such as varying traffic levels and distributions. The document provides a typical link budget example and explains transmitter, receiver, and channel parameters considered in UMTS coverage planning.
This document discusses WCDMA channels at different levels including logical channels, transport channels, and physical channels. It provides details on:
- Logical channels describe the type of information transferred and include control and traffic channels.
- Transport channels describe how logical channels are transferred over the interface and include dedicated and common channels.
- Physical channels provide the transmission medium and are defined by specific codes. They include channels like DPDCH, DPCCH, PDSCH, PRACH, and CPICH.
- The document also discusses the radio frame structure in WCDMA and details on different physical channel types and their characteristics.
The document describes the air interface protocols in LTE including the protocol stack and functions of each layer. The key points are:
- The protocol stack has physical, MAC, RLC, and PDCP layers, along with RRC for control and NAS for non-radio functions.
- The physical layer uses OFDMA for downlink and SC-FDMA for uplink, and provides basic transmission over the air interface.
- MAC handles transport channels, priority, and HARQ. RLC provides segmentation, reassembly, and error correction.
- PDCP performs header compression and ciphering. RRC handles mobility, security, QoS, and NAS message transfer.
-
Radio resource management and mobiltiy mngmntabidsyed4u
Radio resource management deals with managing interference, resources, and transmission characteristics in wireless networks. It involves issues around multi-user and multi-cell capacity. Connectivity is provided through bearer services architecture. Static radio resource management involves fixed cell planning including frequency allocation, base station placement, and parameters. Dynamic RRM adapts to traffic load, user positions, mobility, and quality of service using techniques like power control, channel allocation, and handover criteria. Mobility management is handled by the mobility management entity which tracks user location as users move between tracking areas.
This document provides an overview of the network architecture and signalling protocols in UMTS networks. It describes the main network elements of UTRAN, UE and CN. It explains the interfaces between these elements and the protocols used for communication, including RRC for UE-RNC signalling, RANAP for RNC-CN signalling, and NAS protocols for non-access signalling between UE and CN. It also summarizes the protocol stacks used over the Iu interfaces between RNC and CN for circuit-switched and packet-switched domains.
OTN networks provide transparent transport of client signals while protecting client management information and enabling low latency transport through enhanced fault detection and correction capabilities. Ciena enhances OTN with support for low-rate client interfaces, sub-wavelength grooming to improve efficiency, and intelligent control plane automation. The Optical Transport Network defined in ITU G.709 standards allows convergence of networks through transport of legacy and future client protocols with flexibility.
The document discusses the transition from GSM networks to 3G networks using UMTS (Universal Mobile Telecommunications System) and W-CDMA (Wideband Code Division Multiple Access) technology. It provides an overview of the 3 steps to transition: from current GSM networks to 2.5G networks with GPRS added, to 3G networks using UMTS and W-CDMA. Key aspects of W-CDMA such as its frequencies, multiple access techniques, and spreading codes used are summarized.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document lists important questions for a 1st IA Test on LTE 4G technology. In Module 1, it asks questions about key enabling technologies in OFDM, the LTE SAE architecture, advantages of OFDM for LTE, adaptive modelling and coding, empirical and statistical channel models, and path loss and shadowing. Module 2 questions cover OFDM and SC-FDMA communication systems, timing and frequency synchronization, spatial diversity, spatial multiplexing, multiple antenna transmission and reception, and the PAR problem.
Overview on LTE implementation using XILINX FPGA Graduation Project
Higher Institute of Engineering and Technology - Arish
2016-2017
Supervised by
Dr. Abdelfatah Saad
Eng. Abdelrhman Ahmed
2016-2017
The document discusses uplink power control for 5G networks. It analyzes the performance of turbo codes, subcarrier mapping schemes, and DFT precoded/non-precoded systems over linear and non-linear channels. Simulations were conducted to analyze inter-carrier interference, multi-access interference, and the near-far effect in multi-user systems with different clipping levels. Results showed that DFT precoded systems and BIFDMA mapping performed better than alternatives in non-linear environments. Performance decreased with more users due to increased multi-access interference.
This document provides an introduction to LTE/E-UTRA technology, including both FDD and TDD modes of operation. It describes the key requirements for UMTS Long Term Evolution such as high data rates, low latency, and improved spectrum efficiency compared to previous standards. The document then covers various aspects of the LTE standard, including the OFDMA downlink and SC-FDMA uplink transmission schemes, MIMO concepts, protocol architecture, UE capabilities, and testing considerations. Abbreviations used and additional references are also provided.
This document provides an overview of UMTS W-CDMA (Universal Mobile Telecommunications System Wideband Code Division Multiple Access). It describes the basic architecture and channel structures of a 3G W-CDMA system. Key points include that W-CDMA uses CDMA technology with a chip rate of 3.84 Mcps and channel bandwidth of 4.4-5 MHz. It also discusses the various physical channels in the uplink and downlink, including dedicated channels, common channels, and how they are structured over timeslots and frames.
The document provides an overview of the Long Term Evolution (LTE) mobile telecommunication system. It discusses the evolution of mobile standards leading to LTE and describes key requirements for LTE including increased data rates, reduced latency, improved spectral efficiency, and seamless mobility. Performance targets for LTE are outlined for downlink and uplink peak transmission rates, spectral efficiencies, and latency. LTE is designed to support high speed mobility up to 350 km/h and interoperate with other radio access technologies.
Maria D'cruz_WCDMA UMTS Wireless NetworksMaria D'cruz
The document provides an overview of WCDMA/UMTS architecture and radio resource management. It describes the evolution from 2G to 3G networks and the standardization of WCDMA. The key aspects of WCDMA air interface, UTRAN architecture, core network functionality, and radio resource management techniques like admission control, load control, packet scheduling, handover control and power control are summarized. Diagrams illustrate the system architecture and information flow between network elements.
This document provides an overview of the LTE radio layer 2, radio resource control (RRC), and radio access network architecture. It discusses the E-UTRAN architecture including eNodeBs, home eNodeBs, and relays. It describes the user plane including bearer services, the user plane protocol stack with PDCP, RLC, and MAC layers, and security and transport functions. It also outlines the control plane including connection control and RRC states, and highlights features like interoperability, self-organizing networks, positioning, broadcasting, latency evaluations, and LTE-Advanced.
This document summarizes a research paper that implemented SC-FDMA and OFDMA in MATLAB to evaluate the performance of the LTE physical layer. It provided background on LTE standards and an overview of the key aspects of LTE systems, including frame structure, bandwidth allocation, modulation schemes, and multiple access techniques. The document also reviewed literature on the LTE physical layer design and described how time and frequency resources are divided in LTE.
Overview of LTE Air-Interface Technical White PaperGoing LTE
1) The document discusses Long Term Evolution (LTE), a planned evolution of the 3G UMTS mobile communications standard to improve speed and capacity.
2) It provides an overview of the new LTE E-UTRA air interface, including performance requirements, key technologies like OFDM for downlink and SC-FDMA for uplink, frame structure, and control channel design.
3) Initial system simulations show LTE can provide 2-3x the throughput of existing 3G systems for both uplink and downlink.
TETRA is a trunked radio standard used in public safety networks. It allows for fast call setup, voice and data services, and operates in both infrastructure and ad-hoc modes. UMTS is the 3G cellular standard developed by ETSI for wide-area mobile communication. It uses W-CDMA technology and supports high data rates through variable spreading factors and orthogonal codes. UMTS has an architecture with domains for the user equipment, access network, core network and home network connected by defined interfaces.
This document discusses the key interfaces, architecture, and procedures related to control and user planes, mobility management, and connection management in 3G networks. The control plane handles protocols for controlling radio access bearers and the connection between UE and network. It has physical, data link, and network layers. The user plane is responsible for transferring user data through access and core network protocols. Mobility management allows tracking and delivering services to mobile subscribers via location management, registration, and security functions. Connection management establishes and maintains connections to exchange information with peer entities.
UMTS-WCDMA is a 3G mobile communication standard that uses CDMA technology. It uses wideband CDMA with a chip rate of 3.84 Mcps for its air interface along with orthogonal variable spreading factor codes. The standard defines protocols and procedures for cell search, handover, uplink and downlink physical channels, and support for multirate services through variable spreading factors. Long term targets for UMTS-WCDMA evolution include higher data rates up to 100 Mbps for full mobility and 1 Gbps for low mobility, as well as improved spectral efficiency.
The document provides an overview of advanced wireless networks and UMTS. It discusses the evolution from 2G to 3G networks, including the limitations of 2G and requirements for 3G. It describes the UMTS architecture, including the UTRAN, core network, and protocols on the Iu interface. It also covers basic UMTS principles such as CDMA techniques, radio resources including frequency, time, and power/code, and radio resource management.
Umts Radio Interface System Planning And OptimizationDavid Rottmayer
The document discusses planning and optimizing UMTS radio networks. It begins with an overview of UMTS network architecture and the differences between UMTS and GSM radio system planning. Key aspects of UMTS planning include coverage and capacity planning occurring simultaneously, as capacity requirements influence coverage. The document then covers WCDMA air interface specifications, propagation environments, and the UMTS radio system planning process. It discusses challenges such as varying traffic levels and distributions. The document provides a typical link budget example and explains transmitter, receiver, and channel parameters considered in UMTS coverage planning.
This document discusses WCDMA channels at different levels including logical channels, transport channels, and physical channels. It provides details on:
- Logical channels describe the type of information transferred and include control and traffic channels.
- Transport channels describe how logical channels are transferred over the interface and include dedicated and common channels.
- Physical channels provide the transmission medium and are defined by specific codes. They include channels like DPDCH, DPCCH, PDSCH, PRACH, and CPICH.
- The document also discusses the radio frame structure in WCDMA and details on different physical channel types and their characteristics.
The document describes the air interface protocols in LTE including the protocol stack and functions of each layer. The key points are:
- The protocol stack has physical, MAC, RLC, and PDCP layers, along with RRC for control and NAS for non-radio functions.
- The physical layer uses OFDMA for downlink and SC-FDMA for uplink, and provides basic transmission over the air interface.
- MAC handles transport channels, priority, and HARQ. RLC provides segmentation, reassembly, and error correction.
- PDCP performs header compression and ciphering. RRC handles mobility, security, QoS, and NAS message transfer.
-
Radio resource management and mobiltiy mngmntabidsyed4u
Radio resource management deals with managing interference, resources, and transmission characteristics in wireless networks. It involves issues around multi-user and multi-cell capacity. Connectivity is provided through bearer services architecture. Static radio resource management involves fixed cell planning including frequency allocation, base station placement, and parameters. Dynamic RRM adapts to traffic load, user positions, mobility, and quality of service using techniques like power control, channel allocation, and handover criteria. Mobility management is handled by the mobility management entity which tracks user location as users move between tracking areas.
This document provides an overview of the network architecture and signalling protocols in UMTS networks. It describes the main network elements of UTRAN, UE and CN. It explains the interfaces between these elements and the protocols used for communication, including RRC for UE-RNC signalling, RANAP for RNC-CN signalling, and NAS protocols for non-access signalling between UE and CN. It also summarizes the protocol stacks used over the Iu interfaces between RNC and CN for circuit-switched and packet-switched domains.
OTN networks provide transparent transport of client signals while protecting client management information and enabling low latency transport through enhanced fault detection and correction capabilities. Ciena enhances OTN with support for low-rate client interfaces, sub-wavelength grooming to improve efficiency, and intelligent control plane automation. The Optical Transport Network defined in ITU G.709 standards allows convergence of networks through transport of legacy and future client protocols with flexibility.
The document discusses the transition from GSM networks to 3G networks using UMTS (Universal Mobile Telecommunications System) and W-CDMA (Wideband Code Division Multiple Access) technology. It provides an overview of the 3 steps to transition: from current GSM networks to 2.5G networks with GPRS added, to 3G networks using UMTS and W-CDMA. Key aspects of W-CDMA such as its frequencies, multiple access techniques, and spreading codes used are summarized.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document lists important questions for a 1st IA Test on LTE 4G technology. In Module 1, it asks questions about key enabling technologies in OFDM, the LTE SAE architecture, advantages of OFDM for LTE, adaptive modelling and coding, empirical and statistical channel models, and path loss and shadowing. Module 2 questions cover OFDM and SC-FDMA communication systems, timing and frequency synchronization, spatial diversity, spatial multiplexing, multiple antenna transmission and reception, and the PAR problem.
Overview on LTE implementation using XILINX FPGA Graduation Project
Higher Institute of Engineering and Technology - Arish
2016-2017
Supervised by
Dr. Abdelfatah Saad
Eng. Abdelrhman Ahmed
2016-2017
The document discusses uplink power control for 5G networks. It analyzes the performance of turbo codes, subcarrier mapping schemes, and DFT precoded/non-precoded systems over linear and non-linear channels. Simulations were conducted to analyze inter-carrier interference, multi-access interference, and the near-far effect in multi-user systems with different clipping levels. Results showed that DFT precoded systems and BIFDMA mapping performed better than alternatives in non-linear environments. Performance decreased with more users due to increased multi-access interference.
Since Release 8 Long-Term Evolution (LTE) by the 3rd Generation Partnership Project (3GPP), the uplink control channel called the physical uplink control channel (PUCCH) is specified. In this paper, we propose a new multi-user joint receiver processing for LTE PUCCH that counteracts the intra-cell interference (ICI). Using the fact that the received signal in PUCCH signaling follows a constrained tensor model, a multi-user receiver based on an iterative joint channel/code estimation and symbol detection is proposed. The interest in such a challenging setting relies on the overhead reduction synchronization errors defined by time offset and inaccuracies of timing align. Simulation results show remarkable performance gains of the proposed receiver compared to the conventional time-frequency decorrelator based receiver under the same conditions.
This document evaluates and compares the performance of GFDM and OFDM waveforms in an LTE-A system level study. It finds that GFDM can achieve around 6dB reduction in out-of-band radiation compared to OFDM. BER, PER and throughput are similar between the two waveforms in different channel conditions. GFDM's out-of-band radiation can be reduced further using techniques like guard symbols or windowing. The document concludes that GFDM is a promising candidate for 5G waveforms.
Orthogonal Frequency Division Multiplexing, OFDM uses a large number of narrow sub-carriers for multi-carrier transmission to overcome the effect of multi path fading problem. LTE uses OFDM for the downlink, from base station to terminal to transmit the data over many narrow band careers of 180 KHz each instead of spreading one signal over the complete 5MHz career bandwidth. OFDM meets the LTE requirement for spectrum flexibility and enables cost-efficient solutions for very wide carriers with high peak rates.
The primary advantage of OFDM over single-carrier schemes is its ability to cope with severe channel conditions. Channel equalization is simplified. The low symbol rate makes the use of a guard interval between symbols affordable, making it possible to eliminate inter symbol interference (ISI).
This document presents information on smart antennas. It discusses different types of smart antennas including switched beam antennas and adaptive array antennas. Switched beam antennas form multiple fixed beams while adaptive array antennas can dynamically adjust patterns in response to the signal environment. Space division multiple access is described as an advanced technique that employs smart antennas. Key advantages of smart antennas are also summarized such as improved coverage, interference reduction, and increased system capacity. Applications and limitations of smart antenna systems are provided.
This seminar will provide the basics of this fascinating technology. After attending this seminar you will understand OFDM-principles,
including SC-FDMA as the transmission scheme of choice for the LTE uplink. Multiple antenna technology (MIMO) is a fundamental
part of LTE and its impact on the design of device and network architecture will be explained. Further LTE-related physical layer
aspects such as channel structure and cell search will be presented with an overview of the LTE protocol structure.
The second part of the seminar provides an overview of the evolution in LTE towards 3GPP specification Release 9 and 10. This
includes features and methods for location based services like GNSS support or time delay measurements and the concept of
multimedia broadcast. Finally, we’ll introduce the main features of LTE-Advanced (3GPP Release-10) including carrier aggregation for
a larger bandwidth and backbone network aspects like self-organizing networks and relaying concepts.
LTE was developed to meet increasing demands for mobile data traffic by improving key metrics like latency, throughput, capacity and coverage compared to HSPA. It features flexible bandwidths up to 20MHz, simplified network architecture, advanced antenna techniques and OFDMA/SC-FDMA based access for downlink and uplink respectively. LTE supports peak rates of 300Mbps downlink and 75Mbps uplink depending on UE category and bandwidth. It adopts an all-IP flat architecture with simplified all-packet based transmission procedures.
LTE uses symmetric key cryptography with algorithms like AES and Snow 3G for encryption and integrity protection. During attachment, the UE and MME perform mutual authentication using the AKA protocol and derive session keys from which encryption and integrity keys are obtained for NAS and AS security. The UE and eNB then negotiate the specific algorithms to use for ciphering and integrity protection of signaling and user data.
The document discusses LTE channels and the MAC layer. It describes the functions of the MAC layer, including mapping between transparent and logical channels, error correction through HARQ, and priority handling with dynamic scheduling. It then provides details on the LTE downlink channels, including both logical channels like PCCH, BCCH, CCCH, and DCCH, as well as transport channels like PCH, BCH, DL-SCH, MCH, and PDCCH.
This document provides an overview of the LTE physical channel structure and procedures between the eNB and UE. It describes the LTE architecture and introduces the main physical channels including downlink channels like PBCH, PDCCH, PDSCH and uplink channels like PUSCH, PUCCH, PRACH. It explains the channel mapping and provides examples of the initial access procedure and synchronization signal transmission. Key concepts covered are radio interface protocol stacks, channel coding, multiple access, and reference signals.
Understanding RF Fundamentals and the Radio Design of Wireless NetworksCisco Mobility
The document discusses an advanced session that focuses on understanding radio frequency fundamentals and design of wireless networks, covering topics like 802.11 radio hardware, antenna basics, interpreting antenna patterns, distributed antenna systems, survey tools, and lessons learned from challenging wireless deployments in various environments. The session aims to provide a deep-dive understanding of the radio frequency aspects of wireless LAN design and deployment that are often overlooked. Certain topics related to security, density, location services, and management will not be covered in this session.
This technical white paper provides an overview of Long Term Evolution (LTE):
1) LTE is being developed as the latest mobile network technology by 3GPP to improve end user throughput and latency. 2) LTE uses a new Evolved Packet Core network architecture and Evolved UMTS Terrestrial Radio Access Network, separating control plane and user plane functions. 3) LTE aims to provide downlink peak rates of 100Mbps and uplink of 50Mbps, low latency, and improved spectrum flexibility.
Objective is to include the brief insight on 5G network architecture and standard progress, Accumulated it from different paper/journal, vendor’s white paper and different blog.
4 g(lte) principle and key technology training and certificate 2Taiz Telecom
The document provides an overview of 4G LTE principles and key technologies. It discusses LTE evolution from 3G standards and introduces some of LTE's main features like OFDMA, MIMO and improved spectral efficiency. It describes LTE network elements including eNodeB, MME, SGW, PGW and PCRF. It also covers the LTE air interface and interconnection between network interfaces.
Lte training an introduction-to-lte-basicsSaurabh Verma
The document provides an overview of LTE (Long Term Evolution) technology. It discusses that LTE was standardized by 3GPP in 2008 to improve the performance and efficiency of wireless networks. Key aspects of LTE include the use of OFDMA for downlink and SC-FDMA for uplink, support for flexible bandwidths, and an evolved packet core network architecture. LTE aims to provide higher speeds, lower latency, and more efficient use of spectrum compared to previous 3G technologies.
USING NOMA FOR ENABLING BROADCAST/UNICAST CONVERGENCE IN 5G NETWORKSRajat Yadav
This is presentation is based on a research paper titled "USING NOMA FOR ENABLING BROADCAST/UNICAST
CONVERGENCE IN 5G NETWORKS" published in IEEE TRANSACTIONS ON BROADCASTING, VOL. 66, NO. 2, JUNE 2020.
The document provides an overview of Long Term Evolution (LTE) technology. It discusses that LTE is the next generation mobile network standard that uses an all-IP flat network architecture. LTE networks employ OFDMA for the downlink and SC-FDMA for the uplink. Key performance targets of LTE include peak data rates of over 100 Mbps downlink and 50 Mbps uplink, low latency, and improved spectrum efficiency. The document also outlines the LTE network architecture including components like the eNodeB, MME, SGW, and PGW.
This document discusses radio frequency (RF) planning and optimization for 4G Long Term Evolution (LTE) cellular networks. It begins with an overview of LTE network architecture and physical layer, including the use of frequency division duplexing (FDD) and time division duplexing (TDD). Propagation modeling and cell planning considerations are then covered, such as coverage, cell types, diversity techniques and antenna arrays. The chapter also addresses link budgeting, field measurements, network performance parameters, and postdeployment optimization. The goal of the document is to explain the key aspects of RF planning and design that are essential for deploying and optimizing LTE networks.
The document discusses the evolution of 3G networks to LTE networks. It describes key technologies such as OFDMA, SC-FDMA, and MIMO that improve spectral efficiency and throughput. The LTE network architecture is presented, including elements such as the E-UTRAN, MME, serving gateway, PDN gateway, and HSS. The interfaces between these elements are also outlined.
ABSTRACT : Performance enhancement of smart antennas versus their complexity for commercial wireless
applications. The goal of the study presented in this paper is to investigate the performance improvement
attainable using relatively simple smart antenna techniques when applied to the third-generation W-CDMA air
interface. Methods to achieve this goal include fixed multi beam architectures with different beam selection
algorithms (maximum power criterion, combined beams) or adaptive solutions driven by relatively simple direction
finding algorithms. After comparing these methods against each other for several representative scenarios, some
issues related to the sensitivity of these methods are also studied, (e.g., robustness to environment, mismatches
originating from implementation limitations, etc.). Results indicate that overall, conventional beam forming
seems to be the best choice in terms of balancing the performance and complexity requirements, in particular
when the problem with interfering high-bit-rate W-CDMA 3g users is considered.
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Duplexing mode, ARB and modulation approaches parameters affection on LTE upl...IJECEIAES
The next generation of radio technologies designed to increase the capacity and speed of mobile networks. LTE is the first technology designed explicitly for the Next Generation Network NGN and is set to become the de-facto NGN mobile access network standard. It takes advantage of the NGN's capabilities to provide an always-on mobile data experience comparable to wired networks. In this paper LTE uplink waveforms displayed with various duplexing mode, Allocated Resources Blocks ARB, Modulation types and total information per frame, QPSK and 16 QAM used as modulation techniques and tested under AWGN and Rayleigh channels, similarity and interference of the generated waveforms tested using auto-correlation and cross-correlation respectively.
An adaptive channel estimation scheme based on redundancy minimization for fi...TELKOMNIKA JOURNAL
Filtered orthogonal frequency division multiplexing (F-OFDM), a technology which is being considered as a promising platform for beyond 4G era is expected to help deliver the new features at millimeter wave in the new 5th generation of cellular communication. Some of its key features notably better spectral utilization, enhanced throughput and immunity to interference can be enabling for the new cellular standards. These features of filtered OFDM comes with strict requirements of filter design, guard tone managements, and efficient channel state information harness. This paper is intended to propose an intuitive channel estimation scheme which will allow efficient acquisition of channel state information (CSI) through exploiting the redundant steps of the conventional pilot training-based algorithms and by also using an adaptive weight to expedite the minimization of the error between the estimated values and the actual values. Various simulations will follow to demonstrate the superiority of the scheme over traditional pilot-based algorithms and thus prove its utility in the current 5G cellular era.
This slide for your understanding on LTE !
LTE, the wireless access protocol for 4G mobile network service, has evolved from GSM and WCDMA based on 3GPP!
The contents of this slide is below;
I. LTE Introduction
II. LTE Protocol Layer
III. SAE Architecture
IV. NAS(Non Access Stratum) Protocols
V. EPC Protocol Stacks
With my regards,
Guisun Han
This document provides an overview of LTE functionalities and features. It begins with background on LTE development and standardization. It then describes the LTE network elements and interfaces, including the radio interface between UE and eNB. The document reviews the RRM framework and lists key RRM features, providing status updates on which features are ready in the current release or planned for future releases. It also includes roadmaps showing the planned features and timeline for LTE releases. The document appears to be an internal presentation on LTE technologies and the Nokia Siemens Networks product roadmap.
This document provides an overview of LTE networks and technology. It discusses key aspects of LTE including peak data rates of 50-100 Mbps, reduced latency under 10ms, OFDMA for downlink and SC-FDMA for uplink, support for bandwidths from 1.4-20 MHz, and mobility support up to 350km/h. It also examines the architecture including elements such as the eNodeB, MME, S-GW, P-GW, and interfaces such as S1, X2.
LTE Advanced is an enhancement of the LTE mobile communication standard that aims to improve spectrum efficiency, flexibility, and throughput. Key features of LTE Advanced include support for wider bandwidths up to 100MHz, advanced MIMO technologies with up to 8 antenna ports, improved cell edge performance using Coordinated Multi-Point transmission, and integration of relay nodes to enhance coverage. LTE Advanced is designed to meet the ITU requirements for 4G networks by providing peak data rates of at least 1 Gbps for high mobility communication.
This document provides an overview of the LTE uplink transmission scheme, specifically the use of Single-Carrier Frequency Division Multiple Access (SC-FDMA). SC-FDMA is used instead of OFDMA in the uplink to reduce the high Peak-to-Average Power Ratio (PAPR) of OFDMA. The document describes the SC-FDMA transmission process, including discrete Fourier transforms, subcarrier mapping, and frame structure. It also discusses localized and distributed subcarrier mapping schemes and presents results from a PAPR analysis comparing the schemes. Finally, an adaptive hybrid mapping scheme is proposed to achieve good transmission performance with low PAPR.
The document provides an overview of the 3GPP Long Term Evolution (LTE) cellular network technology. It discusses the goals and key features of LTE, including increased data rates, improved spectral efficiency, scalable bandwidths, OFDM modulation in the downlink, SC-FDMA in the uplink, and multiple antenna techniques. It also describes the LTE network architecture including the Evolved Packet Core and compares LTE to other technologies such as WiMAX.
UMTS (Universal Mobile Telecommunications System) is the 3G mobile communication standard used in Europe and other parts of the world. It uses Wideband Code Division Multiple Access (W-CDMA) technology which spreads user signals across a wide frequency band using unique codes. UMTS allows for higher data rates and new multimedia services compared to 2G systems. Key aspects of UMTS include the use of orthogonal variable spreading factor codes to separate channels, different frequencies for uplink and downlink, and millions of unique scrambling codes to separate users. Capacity is estimated using metrics like signal to interference ratio, processing gain, and the ratio of bit energy to noise density which depends on factors like spreading factor.
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2. The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'07)
III. UL Control Signaling
Table 1. Parameters for UL transmission scheme.
In principle, uplink control signaling can be divided into two
Spectrum SC-FDMA CP duration
Allocation (µs/#of occupied subcarriers (µs)
categories: data-associated and data non-associated control
(MHz) /samples) signaling. Data-associated control signaling is always
transmitted with and used in the processing of data packet.
20 66.67/1200/2048 Examples of this control signaling include transport format,
new data indicator, and MIMO parameters. In LTE it was
15 66.67/900/1536
agreed that this type of control signaling is not necessary.
10 66.67/600/1024
Control signaling not associated with data is transmitted
(4.69 µs) × 12, independently of uplink data packet. Examples of this control
(5.21 µs) × 2 signaling include ACK/NACK, CQI, and MIMO codeword
5 66.67/300/512
feedback. When users have simultaneous uplink data and
3 66.67/144/256 control transmission, control signaling is multiplexed with data
prior to the DFT to preserve the single-carrier property in
1.4 66.67/72/128
uplink transmission. In the absence of uplink data
transmission, this control signaling is transmitted in a reserved
The physical uplink shared channel is defined by one frequency region on the band edge as shown in Figure 3. Note
subframe and the parameters NTx and k0, used in the generation that additional control regions may be defined as needed.
of the SC-FDMA signal. The variables NTx and k0, determining
the transmission bandwidth and the frequency hopping
pattern, respectively, are under control of the uplink scheduler
and may vary on a per-sub-frame basis. The number of SC-
FDMA symbols in a slot depends on the cyclic prefix length
configured by higher layers. The uplink slot format (a sub-
frame consists of two slots) with normal cyclic prefix (CP) is
shown in Figure 2 with seven SC-FDMA symbols. For frames
with extended cyclic prefix, only six SC-FDMA symbols are
present. The uplink supports QPSK, 16-QAM and 64-QAM
modulation. Figure 3. Control regions for uplink.
Tcp Td Allocation of control channels with their small occupied
LB LB
bandwidth to carrier band edge resource blocks reduces out of
Data RS carrier band emissions cause by data resource allocations on
inner band resource blocks and maximizes the frequency
0.5 ms diversity benefit for frequency diverse control channel
Figure 2. Uplink slot format. allocations while preserving the single carrier property of the
uplink waveform. This FDM allocation of control resources to
Two types of reference signals (RS) are supported on the
outer carrier band edge allows an increase in the maximum
uplink - (a) demodulation reference signal, associated with
power level as shown in Figure 4 as well as maximizes the
transmission of uplink data and/or control signaling and (b)
assignable uplink data rate since inserting control regions with
sounding reference signal, not associated with uplink data
transmission used mainly for channel quality determination if consecutive subcarriers in the central portion of a carrier band
requires that the time+frequency resources on either side of the
channel dependent scheduling is used. Orthogonality of
control region to be assigned to different UEs.
reference signals is obtained via frequency domain
multiplexing onto distinct set of sub-carriers. The RS 28.0
QPSK - 5MHz, Band Edge RBs for Data
sequence length is equal to the number of sub-carriers in the
Max Power Level (dBm)
27.0 16QAM - 5MHz, Band Edge RBs for Data
resource blocks. The RS sequence is generated either by QPSK - 5MHz, Band Edge RBs for Ctl
truncation or cyclic extension of ZC (Zadoff-Chu) sequences 26.0
16QAM - 5MHz, Band Edge RBs for Ctl
depending on the allocation size. It was observed that for a 25.0 Max Power Practical Limitation due to EVM
given size, neither truncation nor cyclic extension was the best. and other considerations
24.0
Many options exist for selecting either truncation or cyclic
extension RS construction method, including: 23.0
1. Choose the method that for a given resource block (RB) 22.0
size minimizes the amount of truncation or cyclic extension, 0 2 4 6 8 10 12 14
#RBs of size 25 subcarriers
2. Choose the method that for a given RB size
maximizes the number of sequences with Cubic Metric <= the Figure 4. Increase in maximum power level if control is
target data modulation (e.g., QPSK). mapped to band edge.
3. The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'07)
Table 2 provides the required quality targets for uplink control perform joint channel estimation and decoding. This in turn
signaling. depends on the number of CQI bits to be supported. Two types
of receivers are possible -
Table 2. Uplink control signaling target quality.
• Type 1: Channel estimation is first done based on the
Event Target quality reference signals, and then CQI decoding is
performed based on these channel estimates.
ACK miss detection (1e-2)
• Type 2: Channel estimation and decoding is done
DTX to ACK error (1e-2) jointly using all possible CQI codewords. While this
NACK to ACK error (1e-4) receiver is more complicated than Type 1 receiver,
complexity is manageable for the CQI codeword
CQI block error rate FFS (1e-2 – 1e-1)
length being considered.
A. Channel Quality Information Performance comparison between the two receiver types is
shown in Figure 4 with Type 2 outperforming Type 1 receiver
The CQI structure is shown in Figure 5. The transmission
by approximately 2-3 dB. This is because, for this receiver,
spans the entire 1ms sub-frame and up to six users may be
channel estimation is aided by CQI codeword detection.
multiplexed within the sub-frame via different cyclic shifts of a
However, as shown in Figure 5, two reference signals per slot
Constant Amplitude Zero Auto-Correlation (CAZAC)
were chosen so as not to mandate particular receiver
sequence, e.g. Zadoff-Chu sequence. Data is modulated on top
architecture at the Node B.
of the CAZAC sequence using QPSK modulation.
0
10-bit CQI, TU, QPSK, Non-Ideal Chan Est
10
3 km/h
120 km/h
350 km/h
-1
10
BLER
Receiver Type 2 Receiver Type 1
-2 (24,10), 1 RS (20,10), 2 RS
Figure 5. CQI channel structure. 10
The number of CQI bits may vary between 5-10 bits depending
on whether wideband or narrowband CQI reports are
transmitted. However, larger CQI reports may be transmitted -3
using multiple subframes. In addition, repetition may be used 10
-15 -10 -5 0 5
to ensure reliable reception from cell edge users. An example SNR (dB) per antenna
of CQI performance is shown in Figure 6 for various coding Figure 7. CQI performance with advanced receiver.
schemes.
0
CQI (5-bit, 10-bit), TU, QPSK, Receiver Type 2, Non-Ideal Chan Est B. ACK/NACK
10
Figure 8 illustrates the ACK/NACK channel structure.
Note that in this case only acknowledgment is present (no CQI
-1 or data). To provide the maximum number of multiplexed
10
users, both frequency domain and time domain code
multiplexing are used. In the frequency domain, different
cyclic shifts of a CAZAC sequence are used to differentiate
BLER
users. For instance, with sequence length of 12 corresponding
-2
10
to one resource block, 6 available cyclic shifts are possible. In
5-bit CQI, (32,10) Reed-Muller the time domain, block spreading is used to further multiplex
-3
10
5-bit CQI, Convolutional additional users. For instance, within each cyclic shift of a
5-bit CQI, (24,12) Golay
10-bit CQI, (32,10) Reed-Muller Zadoff-Chu sequence, reference signals are multiplexed using
10-bit CQI, Convolutional
10-bit CQI, (24,12) Golay
DFT code of length 3 while the acknowledgments are
-4 0017
multiplexed using Walsh-Hadamard code of length 4. As a
10
-20 -15 -10 -5 0 result, acknowledgments from 18 different users may be
SNR per antenna (dB)
multiplexed within one resource block. The ACK/NACK is
Figure 6. CQI performance with various coding schemes. then modulated onto the frequency and time-spread sequence.
Both 1-bit and 2-bit acknowledgements are supported using
It should be noted that the number of reference signals required BPSK and QPSK modulations.
depends on the feasibility of using an advanced receiver to
4. The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'07)
0
5-bit CQI, TU (3 km/h), Receiver Type 2, Non-Ideal Chan Est
10
CQI BLER - (20,5) Code
1-bit ACK/NACK SER
-1
10
Error Rate
-2
10
Figure 8. ACK/NACK structure - users are multiplexed using
different cyclic shifts and time-domain spreading. -3
10
Figure 9 shows performance of 1-bit acknowledgments from
18 multiplexed users. Although not shown here, for 2-bit
acknowledgments the performance is approximately 3dB -4
10
worse. -12 -10 -8 -6 -4 -2 0 2
SNR (dB) per antenna
0
10
ACK/NACK Performance - 18 users, GSM-TU (3 km/h) Figure 10. Performance of 5-bit CQI and 1-bit ACK/NACK
3 km/h (BPSK) at TU 3 km/h.
IV. Multiplexing of Control and Data
-1
10
To preserve the single-carrier property of uplink
transmission, L1/L2 control signaling must be multiplexed
with data prior to the DFT when both data and control are to be
transmitted in the same TTI. This may be performed as shown
BER
-2
10
in Figure 11 where uplink data is uniformly punctured to
provide room for control signaling. Naturally, in case of turbo
-3 coding, puncturing is only performed on the parity bits. Since
10
the Node B has prior knowledge of uplink control signaling
transmission, it can easily de-multiplex control and data
packets. In addition, a power boosting factor may be applied
when data is punctured to ensure similar data packet
-4
10
-20 -18 -16 -14 -12 -10 -8
SNR (dB) performance to when control is absent. This is especially
Figure 9. Performance of 1-bit acknowledgments (BPSK) at important in the case of re-transmission since the data MCS
TU 3 km/h. cannot be changed due to synchronous H-ARQ operation in the
uplink. This appropriate power boosting factor (in the order of
C. CQI + ACK/NACK 0.5-1.5dB) can be calculated based on the coding rate
When CQI and ACK/NACK are to be transmitted reduction resulting from puncturing. With appropriate power
simultaneously, they are coded separately and multiplexed in a adjustment there should be little effect on the H-ARQ
TDM fashion. This allows greater control of CQI and performance at the receiver. Of course, power boosting is not
ACK/NACK error requirements, and the ability to multiplex possible when the UE is power-limited (e.g. at the cell edge).
ACK/NACK into CQI reports that are transmitted in multiple
sub-frames (either for large CQI report or through the use of
Puncturing / Sub-carrier CP
repetition) once CQI transmission has started. Figure 10 Data
Insertion
DFT
Mapping
IFFT
Insertion
illustrates the performance of 5-bit CQI + ACK/NACK under Gain
N TX symbols
TU 3 km/h channel with realistic channel estimation. In this Control Factor
Size-NTX Size-N FFT
case, one SC-FDMA symbol per slot was used for
ACK/NACK. Figure 11. Multiplexing of control signaling with data.
As an alternative, scheduling restriction may be used to Figure 12 illustrates typical performance degradation due to
ensure that CQI and ACK/NACK will not be transmitted in the turbo-code puncturing for both QPSK and 16-QAM. From the
same sub-frame. However, this may place unnecessary and figure, it is seen that the performance loss depends on the
complicated constraint on the scheduler. Alternately, only initial coding rate. However, it may be observed that in
ACK/NACK can be transmitted (CQI is not transmitted in the general the amount of resources required to accommodate
sub-frame). This may result in some scheduling and resource control information is small and less than 1dB degradation can
allocation efficiency loss as some CQI reports will be lost. be expected. As a result, appropriate power boosting should be
comfortably accommodated unless the UE is already in a
power-limited situation (e.g. cell edge transmission).
5. The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'07)
4 variable size which must be taken care of by the rate-matching
QPSK
3.5 16-QAM algorithm.
3
CQI Coding Repetition
Puncturing Penalty (dB)
2.5
2 MUX Modulation
1.5
ACK Coding Repetition
1
0.5
Figure 14. Mapping to multiple codewords.
0
Since control is multiplexed with data prior to the DFT,
-0.5
0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8
appropriate modulation and coding selection for control is
Code Rate required for reliable reception. As a result, the amount of
Figure 12. Performance loss due to puncturing (turbo code). coded data to be punctured is variable based upon the MCS
selected for control. In this case, rate matching may be done in
Since both control and data must be transmitted with the one step. With one-step rate matching, the number of bits
same power, reliable reception of control information can be punctured for control is factored in when computing the
achieved through appropriate selection of modulation and effective coding rate.
coding. Since these control fields are generally small,
codeword mapping is use to provide additional protection. V. Conclusions
Subsequent to codeword mapping, repetition (if necessary) and This paper provided an overview of the UL control channel
modulation selection are performed according to information design for 3GPP LTE.
about the channel. Obviously, this selection can be tied to the
MCS of the data block to aid in the decoding. In addition, it REFERENCES
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FDMA or L-FDMA with hopping). This is because these two Evolved UTRAN (E-UTRAN), v.7.3.0, March 2006.
localized transmission methods have different target error rates [2] 3GPP TR 25.814, Physical Layer Aspects for Evolved UTRA, v.2.0.0,
for the same selected MCS. As a result, control power June 2006.
[3] R1-070777, “E-UTRA Multiplexing of UL Control Signaling with Data,”
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data,” Motorola, RAN1#48, St. Louis, USA, Feb 2007.
(a) Single codeword: In this case, all control fields are [6] R1-070162, “EUTRA UL L1/L2 Control Channel Mapping,” Motorola,
mapped into a single codeword (i.e. jointly coded) as shown in RAN1#47bis, Sorrento, Italy, Jan. 2007.
Figure 13. If all fields are not present, dummy input values are [7] R1-070778, “CQI Feedback Overhead with CDM Uplink Control
Channel Region,” Motorola, RAN1#48, St. Louis, USA, Feb 2007.
inserted which are then ignored at the Node B. Alternatively, [8] R1-070275, “Ack/Nack transmission without reference signal overheadin
the UE may use the available fields to transmit some additional E-UTRA UL,” TI, RAN1#47bis, Sorrento, Italy, Jan. 2007.
information based on an agreed upon methodology (e.g. UE [9] R1-070472, “Uplink control Signaling – Summary of e-mail
that does not support MIMO may transmit wideband CQI in discussions”, Ericsson, RAN1#47bis, Sorrento, Italy, Jan. 2007.
the MIMO field). This results in codeword of the same length Note – 3GPP documents may be downloaded from ftp://ftp.3gpp.org
which may simplify the multiplexing and de-multiplexing
process. However, with this approach it may be difficult to
satisfy performance requirements of different control fields.
Also, overhead is higher.
(CQI, ACK, MIMO, ...) Coding Repetition Modulation
Figure 13. Mapping to one codeword.
(b) Multiple codewords: In this case, each control field is
individually mapped to a codeword with its own repetition
factor as shown in Figure 14. This allows individual
adjustments of transmission energy using different coding and
repetition so that performance of each control field can be
controlled. However, this results in a control portion of