carrier aggregation  research papers

carrier aggregation technology is introduced by the 3GPP to support very-high-data-rate transmissions over wide frequency bandwidths (e.g., up to 100 MHz) in its new LTE-Advanced standards. This article first gives a brief review of continuous and non-continuous CA techniques, followed by LTE-Advanced systems, with the requirements of backward compatibility to LTE systems, are highlighted and discussed. Possible technical solutions for the asymmetric CA problem, control signaling design, handover control, and guard band setting are reviewed. Simulation results show Doppler frequency shift has only limited impact on data transmission performance over wide frequency bands in a high-speed mobile environment when the component carriers are time synchronized. The frequency aliasing will generate much more interference between adjacent component carriers and therefore greatly degrades the bit error rate performance of downlink data transmissions In order to meet the strong demand for wireless broadband users, the International Telecommunication Union (ITU) has initiated the standardization process of the next-generation mobile communication systems, entitled IMT-Advanced or fourth-generation (4G) mobile systems . According to the performance and technical requirements defined in , future IMT-Advanced systems can support very high peak data rates for mobile users, up to 1 Gb/s in static and pedestrian environments, and up to 100 Mb/s in high-speed mobile environment. Two international standardization organizations, the Third Generation Partnership Project (3GPP) and research 802.16 Working Group (WG), are actively developing new mobile communication standards for achieving the ambitious performance goals of IMT-Advanced mobile systems . In particular, 3GPP has completed its Long Term Evolution (LTE) standards family Release 8 (R8), which defines and specifies new functions, 3G (B3G) mobile systems. The LTE standards will be further improved to become the LTE-Advanced standards, which will be submitted to the ITU as candidate technical standards for IMT-Advanced systems. The research 802.16 WG is developing an extension of its fixed broadband wireless access standard, called 802.16m, to meet the technical and performance requirements of IMT-Advanced. 3GPP backward compatible with the corresponding LTE systems, but more important, they should fully meet, even exceed, the comprehensive requirements of the ITU’s IMT-Advanced systems on peak data rates, transmission bandwidth, peak/average spectrum efficiency, delay performance in control and user planes, and mobility. Specifically, Table 1 compares the peak, average, and cell-edge spe c t rum e f f i c i enc yr equi r ement s ofthe LTE, LTE-Advanced, and IMT-Advanced systems. Multi-antenna transmission techniques

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Effective carrier aggregation on the LTE-advanced systems
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Abstract The initial release of LTE provided extensive support for deployment in spectrum allocations of various characteristics, with bandwidth ranging roughly from 1.3 MHz up to 20 MHz in both paired and unpaired bands. In LTE release 10 the transmission bandwidth

Advances in carrier aggregation and multi-user MIMO for LTE-advanced: Outcomes from SAMURAI project
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1. Executive Summary To address dramatic increase of the demand for mobile broadband services and to support wider transmissions bandwidths, 3GPP Long Term Evolution (LTE) standard has introduced two powerful techniques, Multi User MIMO (MU-MIMO) and

Carrier Aggregation for High Speed Data in LTE Advanced System
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ABSTRACT One of the most important features to migrate from LTE system to LTE-A system is Carrier aggregation. It is used to achieve high data rates of the order of 1Gbps. Furthermore an LTE Advanced user is backward compatible with LTE. Carrier aggregation is a multi The mixture of users with different capabilities of Carrier Aggregation (CA) presents new challenges to optimise the performance of the next generation wireless pervasive networks. This paper focuses on the joint resources allocation for OFDMA–based multi–carrier

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Abstract Considering the needs of higher data rates and hence wider bandwidths for advanced mobile communication systems, 3GPP standardized carrier aggregation (CA) as one of the important technological components for fourth generation (4G) Long term

Dwell-time based Cell Association with Carrier Aggregation for Heterogeneous Cellular Networks
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ABSTRACT In heterogeneous networks (HetNet), it is an important issue to determine a suitable access network for call request to support seamless service and stable connectivity. For moving user equipment (UE), when and how to select a appropriate cell is more

Digital Cancellation Technique to Mitigate Receiver Desensitization in Cellular Handsets Operating in Carrier Aggregation Mode With Multiple Uplinks and
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ABSTRACT Recent explosive growth in uplink and downlink carrier aggregation in cellular networks is leading to severe desense in receivers for deployment of certain band combinations. In this paper, we studied receiver desense caused by 2nd order

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ABSTRACT Carrier Aggregation (CA) is one of the core proposals of LTE-A for bandwidth expansion from current limit of 20MHz obtainable in LTE systems to 100MHz for LTE- Advanced in order to meet ever increasing demand for high speed mobile broadband

Carrier Aggregation-Opportunities and Challenges
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ABSTRACT Carrier Aggregation (CA) is one of the most substantial functionalities introduced in 3GPP Release 10. In terms of spectrum usage it provides extra flexibility for the mobile network operators. Simultaneously it can offer increased peak throughput to the users.

Dynamic Spectrum Access for Primary Operators Via Carrier Aggregation in LTE-Advanced Environments
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Page 1. Dynamic Spectrum Access for Primary Operators Via Carrier Aggregation in LTE-Advanced Environments * Keywords Dynamic spectrum access; auction; peak load pricing, carrier aggregation; knapsack problem.

Delay over Joint User Scheduling Scheme (JUS) and Separated Random User Scheduling Scheme (SRUS) in LTE-A System With Carrier Aggregation
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Abstract In Long Term Evolution Advanced (LTE-A), the signal quality in a wireless channel is estimated based on the channel quality measurements. The measurement results are used to select suitable modulation and coding scheme for each transmission, feedback

Improved Scheduling Techniques for Efficient Uplink Communications with Carrier Aggregation
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ABSTRACT Transmitted power in Long Term Evolution-Advanced (LTE-A) uplink (UL) is strongly related to the number of physical resource blocks (PRBs) allocated. As the transmitted bandwidth increases power does so. However, this rise in power is also

Resource Allocation and Interference Management for LTE-Advanced Systems with Carrier Aggregation
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Abstract Carrier aggregation is one of the promising features that enables expanding the bandwidth of the Long Term Evolution-Advanced (LTE-A) system through aggregating multiple LTE component carriers (CCs) to support high data rate up to 1 Gbit/s. In this

Interference-Aware Resource Scheduling in LTE HetNets with Carrier Aggregation Support
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ABSTRACT In this work we address the resource allocation problem in a two-tier LTE HetNet with carrier aggregation support, serving a mix of users with CA-enabled and legacy terminals. We consider that all basestations (macro or micro) share all the available

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Abstract Multiple access and transmission enhancement in support of carrier aggregation techniques has been actively studied in the 3GPP LTE-Advanced standardization process of the next-generation mobile broadband communication systems. By means of carrier

Carrier Aggregation as a Repeated Game: Learning Algorithms for Efficient Convergence to a Nash Equilibrium
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ABSTRACT Carrier aggregation is a key feature of next generation wireless networks to deliver high-bandwidth links. This paper studies carrier aggregation for autonomous networks operating in shared spectrum. In our model, networks decide how many and

A Component Carrier Selection Algorithm Based on Channel Quality for LTE-Advanced System with Carrier Aggregation
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Abstract In this paper we focus on component carriers (CC) selection for carrier aggregation (CA) in LTE-Advanced system. Since there are more than one CCs, how to assign CCs to each user needs to be considered. For discontinuous CA scene, the traditional algorithms,

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ABSTRACT Although LTE-Advanced system is targeted at enhancing the users' throughput and increasing connection reliability, however user's mobility tends to degrade the efficiency of the services and applications in terms of throughput degradation and outage probability

HARQ Process Mapping Mechanism in LTE-Advanced System with Carrier Aggregation
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Abstract This paper analyzes the static mapping and flexible mapping mechanism of HARQ process with carrier aggregation, and then improves the flexible mapping of HARQ process which not only can guarantee the improvement of system performance but also is able to