LTE Advanced

About: LTE Advanced is a research topic. Over the lifetime, 4055 publications have been published within this topic receiving 74262 citations. The topic is also known as: Long-Term Evolution Advanced & LTE-A.

The Evolution of LTE Physical Layer Control Channels

Abstract: Physical layer control signals in cellular communications serve the purpose of delivering physical layer control messages in a timely fashion to support cell radio resource management and data transmissions between the network and the mobile users. This article describes the evolution of 3GPP LTE in control channel design. The legacy LTE control channels (Release 8) have proven to be well-designed robust channels for signaling physical layer messages. However, emerging wireless communication transmission technologies continue to challenge the traditional design of LTE control channels. We have reached a point where a totally new design of the control channels has to be provided in order for the new transmission features to be introduced into LTE. In this article we first give an overview of the legacy LTE control channel, and present the new challenges. We then describe in depth the new solutions provided by LTE (Release 11). Finally, we address the limitations of the new design, which are recently identified in certain newly-emerging applications, in particular, the machine-type communications. A new round of evolution is hence imperative. New solutions provided by next release of LTE (Release 13) are presented.

Efficient Random Access Channel Evaluation and Load Estimation in LTE-A With Massive MTC

Abstract: The deployment of machine-type communications (MTC) together with cellular networks has a great potential to create the ubiquitous Internet-of-Things environment. Nevertheless, the simultaneous activation of a large number of MTC devices (named UEs herein) is a situation difficult to manage at the evolved Node B (eNB). The knowledge of the joint probability distribution function (PDF) of the number of successful and collided access requests within a random access opportunity (RAO) is a crucial piece of information for contriving congestion control schemes. A closed-form expression and an efficient recursion to obtain this joint PDF are derived in this paper. Furthermore, we exploit this PDF to design estimators of the number of contending UEs in an RAO. Our numerical results validate the effectiveness of our recursive formulation and show that its computational cost is considerably lower than that of other related approaches. In addition, our estimators can be used by the eNBs to implement highly efficient congestion control methods.

On the Accurate Performance Evaluation of the LTE-A Random Access Procedure and the Access Class Barring Scheme

Abstract: The performance evaluation of the random access (RA) in LTE-A has recently become a major research topic as these networks are expected to play a major role in future 5G networks. Up to now, the key performance indicators (KPIs) of the RA in LTE-A have been obtained either by performing a large number of simulations or by means of analytic models that, oftentimes, sacrifice precision in exchange for simplicity. In this paper, we present an analytical model for the performance evaluation of the LTE-A RA procedure that incorporates the access class barring (ACB) scheme. By means of this model, each and every one of the KPIs suggested by the 3GPP can be obtained with minimal error when compared with results obtained by simulation. To the best of our knowledge, this paper presents the most accurate analytical model, which can be easily adapted to incorporate modifications of network parameters and/or extensions to the LTE-A system. In addition, our model of the ACB scheme can be easily incorporated to other analytic models of similar nature without further modifications.

Joint parameter determination and separate cqi generation reporting for lte-a multicarrier

Abstract: Certain aspects of the present disclosure relate to a method for determining and reporting channel information feedback for multi-carrier operation. In one aspect, channel information feedback parameters may be determined jointly across component carriers, and channel information feedback reports may be generated and reported individually per component carrier.

LTE-Advanced: The mainstream in mobile broadband evolution

Abstract: Requirements for LTE-Advanced were defined in June 2008 and since then it has been developed and evaluated in 3GPP RAN Working Groups. LTE-Advanced Study Item is to be completed in March 2010 and several LTE Release 10 Work Items have already been kicked off. This paper addresses the state of LTE-Advanced standardization, performance and network deployments in February 2010.