LTE-advanced: next-generation wireless broadband technology [Invited Paper]
TL;DR: An overview of the techniques being considered for LTE Release 10 (aka LTEAdvanced) is discussed, which includes bandwidth extension via carrier aggregation to support deployment bandwidths up to 100 MHz, downlink spatial multiplexing including single-cell multi-user multiple-input multiple-output transmission and coordinated multi point transmission, and heterogeneous networks with emphasis on Type 1 and Type 2 relays.
Abstract: LTE Release 8 is one of the primary broadband technologies based on OFDM, which is currently being commercialized. LTE Release 8, which is mainly deployed in a macro/microcell layout, provides improved system capacity and coverage, high peak data rates, low latency, reduced operating costs, multi-antenna support, flexible bandwidth operation and seamless integration with existing systems. LTE-Advanced (also known as LTE Release 10) significantly enhances the existing LTE Release 8 and supports much higher peak rates, higher throughput and coverage, and lower latencies, resulting in a better user experience. Additionally, LTE Release 10 will support heterogeneous deployments where low-power nodes comprising picocells, femtocells, relays, remote radio heads, and so on are placed in a macrocell layout. The LTE-Advanced features enable one to meet or exceed IMT-Advanced requirements. It may also be noted that LTE Release 9 provides some minor enhancement to LTE Release 8 with respect to the air interface, and includes features like dual-layer beamforming and time-difference- of-arrival-based location techniques. In this article an overview of the techniques being considered for LTE Release 10 (aka LTEAdvanced) is discussed. This includes bandwidth extension via carrier aggregation to support deployment bandwidths up to 100 MHz, downlink spatial multiplexing including single-cell multi-user multiple-input multiple-output transmission and coordinated multi point transmission, uplink spatial multiplexing including extension to four-layer MIMO, and heterogeneous networks with emphasis on Type 1 and Type 2 relays. Finally, the performance of LTEAdvanced using IMT-A scenarios is presented and compared against IMT-A targets for full buffer and bursty traffic model.
Citations
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07 Apr 2013
TL;DR: A new uplink power control scheme is proposed, which sets the UL SinR target by considering the interference generated to neighboring cells, and interference over thermal (IoT) status from neighboring cells is used to adaptively adjust the SINR target in order to avoid snow avalanche effects.
Abstract: In heterogeneous networks (HetNet) comprising high power Macro cells and low power small cells, cross-tier interference limits overall capacity with universal frequency reuse. Conventional fractional power control scheme can not effectively deal with interference between Macro cell and small cells. In this paper, we proposed a new uplink power control scheme,which sets the UL SINR target by considering the interference generated to neighboring cells. Furthermore, interference over thermal (IoT) status from neighboring cells is used to adaptively adjust the SINR target in order to avoid snow avalanche effects. Simulation results show that the proposed scheme outperforms traditional fractional power control scheme in terms of both edge performance and average performance.
12 citations
TL;DR: In this article, a power allocation algorithm with polynomial complexity is investigated to improve the energy efficiency (EE) of the unlicensed secondary users (SU), where the feasible range of power consumption ratio using Karush-Kuhn-Tucker optimality conditions to support each SU's minimum quality of service and the effectiveness of successive interference cancellation.
Abstract: Non-orthogonal multiple access is a promising technique to meet the harsh requirements for the internet of things devices in cognitive radio networks. To improve the energy efficiency (EE) of the unlicensed secondary users (SU), a power allocation (PA) algorithm with polynomial complexity is investigated. We first establish the feasible range of power consumption ratio using Karush-Kuhn-Tucker optimality conditions to support each SU's minimum quality of service and the effectiveness of successive interference cancellation. Then, we formulate the EE optimization problem considering the total transmit power requirements which leads to a non-convex fractional programming problem. To efficiently solve the problem, we divide it into an inner-layer and outer-layer optimization sub-problems. The inner-layer optimization which is formulated to maximize the sub-carrier PA coefficients can be transformed into the difference of convex programming by using the first-order Taylor expansion. Based on the solution of the inner-layer optimization sub-problem, the concave-convex fractional programming problem of the outer-layer optimization sub-problem may be converted into the Lagrangian relaxation model employing the Dinkelbach algorithm. Simulation results demonstrate that the proposed algorithm has a faster convergence speed than the simulated annealing algorithm, while the average system EE loss is only less than 2%.
12 citations
Patent•
24 Apr 2013TL;DR: In this paper, the authors provide apparatus and methods for improved indication of cell information in a wireless network, which may include an evolved Node B (eNB) carrier type, synchronization information and Radio Resource Management (RRM) measurement information.
Abstract: Generally, this disclosure provides apparatus and methods for improved indication of cell information in a wireless network. The cell information may include an evolved Node B (eNB) carrier type. The UE device may include a receiver circuit configured to receive a Radio Resource Control (RRC) message from an evolved Node B (eNB) of a serving cell, the RRC message comprising carrier information associated with the serving cell eNB; a processing circuit configured to extract, from the serving cell eNB carrier information: a carrier type, synchronization information and Radio Resource Management (RRM) measurement information; a synchronization circuit configured to synchronize the UE to the serving cell eNB based on the synchronization information associated with the serving cell eNB carrier information; and a signal measurement circuit configured to perform RRM signal measurements on the serving cell eNB based on the RRM measurement information associated with the serving cell eNB carrier information.
12 citations
Book•
01 Aug 2015TL;DR: This book is to demonstrate the use of a comparative evaluation framework based on these despeckle filters (introduced on book 1) on cardiovascular ultrasound image and video processing and analysis.
Abstract: In ultrasound imaging and video visual perception is hindered by speckle multiplicative noise that degrades the quality. Noise reduction is therefore essential for improving the visual observation quality or as a pre-processing step for further automated analysis, such as image/video segmentation, texture analysis and encoding in ultrasound imaging and video. The goal of the first book (book 1 of 2 books) was to introduce the problem of speckle in ultrasound image and video as well as the theoretical background, algorithmic steps, and the MatlabTM for the following group of despeckle filters: linear despeckle filtering, non-linear despeckle filtering, diffusion despeckle filtering, and wavelet despeckle filtering. The goal of this book (book 2 of 2 books) is to demonstrate the use of a comparative evaluation framework based on these despeckle filters (introduced on book 1) on cardiovascular ultrasound image and video processing and analysis. More specifically, the despeckle filtering evaluation framework is based on texture analysis, image quality evaluation metrics, and visual evaluation by experts. This framework is applied in cardiovascular ultrasound image/video processing on the tasks of segmentation and structural measurements, texture analysis for differentiating between two classes (i.e. normal vs disease) and for efficient encoding for mobile applications. It is shown that despeckle noise reduction improved segmentation and measurement (of tissue structure investigated), increased the texture feature distance between normal and abnormal tissue, improved image/video quality evaluation and perception and produced significantly lower bitrates in video encoding. Furthermore, in order to facilitate further applications we have developed in MATLABTM two different toolboxes that integrate image (IDF) and video (VDF) despeckle filtering, texture analysis, and image and video quality evaluation metrics. The code for these toolsets is open source and these are available to download complementary to the two monographs.
12 citations
TL;DR: An overview of the LTE Network Architecture is illustrated and some drawbacks in LTE security framework are discussed, and hopefully this will be a guideline for the new learners.
Abstract: With all these years’ rapid development in wireless communication, high demands for broadband mobile wireless communications and the emergence of new wireless multimedia applications have constituted the motivation to the development of broadband wireless access technologies. The Long Term Evolution (LTE) system has been specified by the Third Generation Partnership Project (3GPP) on the way towards fourth-generation (4G) mobile to ensure 3GPP keeping the dominance of the cellular communication technologies. In this paper, several security issues of the LTE and LTE-A networks have been discussed. First, we illustrate an overview of the LTE Network Architecture. Second, LTE security architecture is shown as well. Third, some drawbacks in LTE security framework are discussed in Section 4. Finally, some open issues will be talked, and hopefully this will be a guideline for the new learners.
12 citations
Cites background from "LTE-advanced: next-generation wirel..."
...Third, some drawbacks in LTE security framework are discussed in Section 4....
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References
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01 Sep 2006
TL;DR: A preliminary look at the air interface for Evolved UTRA (E-UTRA) and associated key technologies required to reach its design objectives are provided.
Abstract: With the emergence of packet-based wireless broadband systems such as 802.16e, it is evident that a comprehensive evolution of the universal mobile telecommunications system specifications is required to remain competitive. As a result, work has begun on long term evolution (LTE) of the UMTS terrestrial radio access and radio access network aimed for commercial deployment in 2010. Goals for the evolved system include support for improved system capacity and coverage, high peak data rates, low latency, reduced operating costs, multi-antenna support, flexible bandwidth operations and seamless integration with existing systems. To reach these goals, a new design for the air interface is envisioned. This paper provides a preliminary look at the air interface for Evolved UTRA (E-UTRA) and associated key technologies required to reach its design objectives. Initial E-UTRA system performance results show a 2 to 3x improvement over a reference Rel-6 UMTS system configuration [1, 2] for both uplink and downlink.
30 citations
24 Oct 2008
TL;DR: The proposed channel estimation technique is shown to have significant gains in performance compared to other well known channel estimation techniques such as the maximum-likelihood (ML) and the inverse fast Fourier transform (IFFT) channel estimation methods.
Abstract: The performance of the uplink physical channel of the 3GPP LTE system is considered in this paper. Assuming a single user spatial division multiple access transmission scheme, where users' signals are transmitted over different subcarriers, a low complexity channel estimation technique is proposed for the physical uplink shared channel (PUSCH). The proposed channel estimation technique is shown to have significant gains in performance compared to other well known channel estimation techniques such as the maximum-likelihood (ML) and the inverse fast Fourier transform (IFFT) channel estimation methods [5]. Simulation results for different channel models and modulation and coding schemes (MCS) using incremental redundancy (IR) based hybrid automatic repeat request (HARQ) operation are also shown. Finally, a robust detection scheme is proposed for the physical uplink control channel (PUCCH) and simulation results are summarized.
10 citations
"LTE-advanced: next-generation wirel..." refers methods in this paper
...The DFT precoding operation is performed to reduce the cubic metric (CM) of the signal, leading to higher maximum transmit power [2]....
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