Evolved UMTS Terrestrial Radio Access Research Articles

LTE channel throughput assessment and comparison under different terrain

SummaryIn evolved UMTS terrestrial radio access network, long‐term evolution is known as the fourth‐generation mobile network with a leading radio performance metric as a throughput and signal‐to‐noise ratio (SNR) that affect the radio links. In this paper, we analytically describe the different long‐term evolution propagation model and measure and compare the throughput and SNR on different Doppler frequencies. To validate the performance of channel, we implement network on 3 standard models, viz, as pedestrian (EPA), vehicular (EVA), and typical urban (ETU) at different Doppler frequency (5, 70, 300, and 750 Hz), and different value of SNR (10, 13, 16, and 19 dB) on downlink channel and measured the channel throughput rate. We conclude that a performance of the channel for high SNR values severely affected by the high value of the Doppler frequency while for the channels at low SNR values is a negligible effect with high Doppler frequency.

Comparative performance analysis of different resource scheduler and characterising the impact of proportional fair under different TTI feedback delay in EUTRA network

Evolved UMTS terrestrial radio access network (EUTRAN) offers high uplink and downlink throughput. In this paper, we investigate the performance of five different schedulers of media access control for resource allocation, such as round robin (RB), proportional fair (PF), best channel quality indicator (CQI), max transmission point (TP) and resource fair (RF). On comparing the performance of resource allocation schedulers in the indistinguishable arrangement, we found the proportional fair (PF) offers balance in terms of individual metrics. Furthermore, we analyse the effect of feedback transmission time interval (TTI) delay on two typical EUTRAN networks referred to as long term evolution (LTE) and LTE-Advance (LTE-A). We evaluate the performance of the PF scheduler for both networks under varying feedback delay in TTI. Simulated results show that the delay in TTI affects the performance of resource allocation. Feedback delay improves network performance by compensating effect of imperfect channel.

Comparative performance analysis of different resource scheduler and characterising the impact of proportional fair under different TTI feedback delay in EUTRA network

Evolved UMTS terrestrial radio access network (EUTRAN) offers high uplink and downlink throughput. In this paper, we investigate the performance of five different schedulers of media access control for resource allocation, such as round robin (RB), proportional fair (PF), best channel quality indicator (CQI), max transmission point (TP) and resource fair (RF). On comparing the performance of resource allocation schedulers in the indistinguishable arrangement, we found the proportional fair (PF) offers balance in terms of individual metrics. Furthermore, we analyse the effect of feedback transmission time interval (TTI) delay on two typical EUTRAN networks referred to as long term evolution (LTE) and LTE-Advance (LTE-A). We evaluate the performance of the PF scheduler for both networks under varying feedback delay in TTI. Simulated results show that the delay in TTI affects the performance of resource allocation. Feedback delay improves network performance by compensating effect of imperfect channel.

A SiGe BiCMOS Power Amplifier Using a Lumped Element-Based Impedance Tuner

A dual-path multi-band power amplifier (PA) with a tunable output matching network is presented for long-term- evolution (LTE) handset applications. To optimize output load impedances for various power regions with various frequency bands, an impedance tuner implemented using lumped elements is used. The dual-path multi-band PA fabricated using $0.35{\mathchar702D}\mu{\rm m}$ SiGe BiCMOS process is evaluated for the evolved UMTS terrestrial radio access (E-UTRA) bands 1, 2, 3, 5, and 8 with a 10 MHz bandwidth (BW) LTE 16 quadrature amplitude modulation signal having a peak-to-average ratio of 6.4 dB.

A multiband power amplifier using a switch‐based reconfigurable matching network for optimized power performance

ABSTRACTA multiband power amplifier (MBPA) with a switch‐based reconfigurable output matching network is presented for long‐term evolution handset applications. The MBPA is designed in a dual‐path configuration to improve efficiency in two different power levels for different frequency bands of the evolved UMTS terrestrial radio access (E‐UTRA). The dual‐path MBPA with the switch‐based reconfigurable output matching network delivered a collector efficiency of 31.8–38.5%, while satisfying the linearity specification (i.e., an adjacent channel leakage ratio less than −30 dBc) at an output power of 26.5 dBm across the five popular frequency bands of the E‐UTRA. In the low power mode, the MBPA delivered a collector efficiency of 21.8–35.4% with an adjacent channel leakage ratio smaller than −32.3 dBc at an average output power of 18 dBm. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2881–2884, 2014

A multiband power amplifier with a tunable transmission line for mobile LTE applications

AbstractA power amplifier (PA) for multiband applications implemented with a tunable load modulation technique is presented. The broadband output matching can be done by load modulation implemented by modification of the characteristic impedance (ZC) of the tunable transmission line. The multiband PA delivered a gain of more than 10.5 dB, an adjacent‐channel‐leakage ratio of evolved UMTS terrestrial radio access adjacent channel leakage ratio (E‐UTRA) lower than −30 dBc, and a power added efficiency of 28–31% at the output power of 26‐dBm and the frequency range of 1.5–2.05 GHz with a 10‐MHz 16QAM long‐term evolution signal. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1175–1178, 2014

Multiple-Access Technology of Choice In 3GPP LTE

Third-Generation Partnership Project (3GPP) standardizes an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) as air interface in its release 8 LTE. Orthogonal Frequency Division Multiple Access ( OFDMA) and Single Carrier-Frequency Division Multiple Access(SC-FDMA)are key technologies for the air interface of mobile broadband systems.It is evident that mobile broadband access technologies are reaching a commonality in the air interface and networking architecture; they are being converged to an IP-based network architecture with OFDMA based air interface technology. The air interface of E-UTRAN is based on OFDMA in downlink and SC-FDMA in the uplink, making it possible to efficiently utilize bandwidth due to the orthogonally between sub-carriers and by assigning subsets of sub-carriers to individual users which allows for simultaneous data rate transmission from several users and differentiated quality of service for each user. In this paper, wehighlight the technologies behindOFDMA and SC-FDMA and also carry out performance comparison of the two air interface technologies. We brieflydescribe the 3GPP LTE standard, and its implementation using OFDMA and SC-FDMA technology.

MULTIPLE-ACCESS TECHNOLOGY OF CHOICE IN 3GPP LTE

Third-Generation Partnership Project (3GPP) standardizes an Evolved UMTS Terrestrial Radio Access Network (EUTRAN)as air interface in its release 8 LTE. Orthogonal Frequency Division Multiple Access(OFDMA) and Single Carrier-Frequency Division Multiple Access(SC-FDMA)are key technologies for the air interface of mobile broadband systems.It is evident that mobile broadband access technologies are reaching a commonality in the air interface and networking architecture; they are being converged to an IP-based network architecture with OFDMA based air interface technology. The air interface of E-UTRAN is based on OFDMA in downlink and SC-FDMA in the uplink, making it possible to efficientl utilize bandwidth due to the orthogonally between sub-carriers and by assigning subsets of sub-carriers to individual users which allows for simultaneous data rate transmission from several users and differentiated quality of service for each user. In this paper, wehighlight the technologies behindOFDMA and SC-FDMA and also carry out performance comparison of the two air interface technologies. We brieflydescribe the 3GPP LTE standard, and its implementation using OFDMA and SC-FDMA technology.

LTE-advanced and the evolution of LTE deployments

The fourth generation (4G) wireless technology known as Long Term Evolution (LTE) allows cellular operators to use new and wider spectrum and complements third generation (3G) networks with higher user data rates, lower latency, and a flat Internet Protocol (IP)-based network architecture. The LTE standard was first published in March 2009 as part of the Third Generation Partnership Project (3GPP) Release 8 specifications. The specifications have been in development since 2005 when 3GPP defined LTE requirements and performance goals to significantly improve on the 3GPP Release 6 standard, which was at that point the state of the art. Achieving those goals required an evolution of both the air interface and the network architecture, now known as Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) and Evolved Packet Core (EPC), respectively. The very first commercial LTE networks were deployed on a limited scale in Scandinavia at the end of 2009, and currently, large-scale deployments are taking place in several regions, including North America, Europe, and Asia.

Self-optimization of LTE networks utilizing Celnet Xplorer

In order to meet demanding performance objectives in Long Term Evolution (LTE) networks, it is mandatory to implement highly efficient, autonomic self-optimization and configuration processes. Self-optimization processes have already been studied in second generation (2G) and third generation (3G) networks, typically with the objective of improving radio coverage and channel capacity. The 3rd Generation Partnership Project (3GPP) standard for LTE self-organization of networks (SON) provides guidelines on self-configuration of physical cell ID and neighbor relation function and self-optimization for mobility robustness, load balancing, and inter-cell interference reduction. While these are very important from an optimization perspective of local phenomenon (i.e., the eNodeB's interaction with its neighbors), it is also essential to architect control algorithms to optimize the network as a whole. In this paper, we propose a Celnet Xplorer-based SON architecture that allows detailed analysis of network performance combined with a SON control engine to optimize the LTE network. The network performance data is obtained in two stages. In the first stage, data is acquired through intelligent non-intrusive monitoring of the standard interfaces of the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) and Evolved Packet Core (EPC), coupled with reports from a software client running in the eNodeBs. In the second stage, powerful data analysis is performed on this data, which is then utilized as input for the SON engine. Use cases involving tracking area optimization, dynamic bearer profile reconfiguration, and tuning of network-wide coverage and capacity parameters are presented.

3GPP LTE: The Future of Mobile Broadband

The mobile broadband technologies are reaching a commonality in the air interface and networking architecture; they are being converged to an IP-based network architecture with Orthogonal Frequency Division Multiple Access (OFDMA) based air interface technology. From technical perspective, fundamental goal of mobile broadband is to offer higher data rates with reduced latency. The third Generation Partnership Project (3GPP) presents the Long-Term Evolution (LTE) project in order to accommodate increasing mobile data usage and new multimedia applications. In the near future, with the recent progress made by technical specifications and vendor technology demonstrations LTE will emerge as successor to cellular systems as a broadband wireless solution. This paper provides an overview of 3GPP LTE including its history, features, technology, architecture and future. The technology components include OFDMA air-interface, Multiple-Input and Multiple-Output (MIMO) antenna technology and higher order modulation. The architecture includes Evolved Packet Core (EPC) and Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) components. This paper will concentrate to describe the main functions of the most important network elements. Also, the aim of this paper is to present the future potential of LTE which will make it an inevitable choice for wireless network operators around the globe.

Investigation of Inter-Node B Macro Diversity for Single-Carrier Based Radio Access in Evolved UTRA Uplink

This paper investigates the gain of inter-Node B macro diversity for a scheduled-based shared channel using single-carrier FDMA radio access in the Evolved UTRA (UMTS Terrestrial Radio Access) uplink based on system-level simulations. More specifically, we clarify the gain of inter-Node B soft handover (SHO) with selection combining at the radio frame length level (=10msec) compared to that for hard handover (HHO) for a scheduled-based shared data channel, considering the gains of key packet-specific techniques including channel-dependent scheduling, adaptive modulation and coding (AMC), hybrid automatic repeat request (ARQ) with packet combining, and slow transmission power control (TPC). Simulation results show that the inter-Node B SHO increases the user throughput at the cell edge by approximately 10% for a short cell radius such as 100-300m due to the diversity gain from a sudden change in other-cell interference, which is a feature specific to full scheduled-based packet access. However, it is also shown that the gain of inter-Node B SHO compared to that for HHO is small in a macrocell environment when the cell radius is longer than approximately 500m due to the gains from hybrid ARQ with packet combining, slow TPC, and proportional fairness based channel-dependent scheduling.

Physical Channel Structures and Cell Search Method for Scalable Bandwidth for OFDM Radio Access in Evolved UTRA Downlink

This paper proposes physical channel structures and a cell search method for OFDM based radio access in the Evolved UTRA (UMTS Terrestrial Radio Access) downlink, which supports multiple scalable transmission bandwidths from 1.25 to 20 MHz. In the proposed physical channel structures, the central sub-carrier of the OFDM signal is located on the frequency satisfying the 200-kHz raster condition regardless of the transmission bandwidth of the cell site. Moreover, the synchronization channel (SCH) and broadcast channel (BCH), which are necessary for cell search, are transmitted in the central part of the entire transmission spectrum with a fixed bandwidth. In the proposed cell search method, a user equipment (UE) acquires the target cell in the cell search process in the initial or connected mode employing the SCH and possibly the reference signal, which are transmitted in the central part of the given transmission bandwidth. After detecting the target cell, the UE decodes the common control information through the BCH, which is transmitted at the same frequency as the SCH, and identifies the transmission bandwidth of the cell to be connected. Computer simulations show the fast cell search performance made possible by using the proposed SCH structure and the cell search method.