scispace - formally typeset
Search or ask a question
Journal Article•DOI•

LTE-advanced: next-generation wireless broadband technology [Invited Paper]

Amitava Ghosh1, Rapeepat Ratasuk1, Bishwarup Mondal1, Nitin Mangalvedhe1, Timothy A. Thomas1 •
Motorola1
01 Jun 2010-IEEE Wireless Communications (IEEE Press)-Vol. 17, Iss: 3, pp 10-22
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
More filters
Journal Article•DOI•
Directly modulated laser-based optical radio frequency self-interference cancellation system

[...]

Zhang Shaojie1, Shilin Xiao1, Yunhao Zhang1, Hanlin Feng1, Lu Zhang1, Zhao Zhou •
Shanghai Jiao Tong University1
01 Feb 2016-Optical Engineering
TL;DR: In this article, a microwave photonics system for radio frequency self-interference cancellation using optical techniques was proposed, which employs two low-cost directly modulated lasers and a balanced photodetector to subtract the strong selfinterference signal from a corrupted received signal.
Abstract: We propose a microwave photonics system for radio frequency self-interference cancellation using optical techniques. With a simple structure, this system employs two low-cost directly modulated lasers and a balanced photodetector to subtract the strong self-interference signal from a corrupted received signal. For commonly used wireless applications, 40-dB cancellation within 900-MHz band and 33-dB cancellation within 2.4-GHz band are experimentally obtained, both over 400-MHz bandwidth. Moreover, for ultra-wideband cancellation, this system achieves more than 27-dB cancellation over 6-GHz bandwidth. The experimental results show good recovery of the weak signal of interest buried by strong self-interference after the cancellation.

24 citations

Proceedings Article•DOI•
Beam broadening for phased antenna arrays using multi-beam subarrays

[...]

Sridhar Rajagopal1•
Samsung1
10 Jun 2012
TL;DR: This paper provides a systematic approach for beam broadening for phased antenna arrays, with unit amplitude constraint and without turning off antennas, using multi-beam subarrays and without any increase in hardware complexity.
Abstract: Consideration of mmWave frequencies with large phased antenna arrays has become increasingly important for providing multi-Gb/s wireless data communication. However, large phased antenna arrays tradeoff gain for very narrow beam widths, which may not always be desirable for outdoor, mobile communication. This paper provides a systematic approach for beam broadening for phased antenna arrays, with unit amplitude constraint and without turning off antennas, using multi-beam subarrays and without any increase in hardware complexity. We first show that the beam resulting from the full array lies in the region defined by the sum of the individual subarrays and beams can be shaped within the region using RF or baseband phase precoding. While both conjugating and flipping the weights for subarrays generate similar subarray responses, only flipping the weights guarantees a symmetric response of the full array about boresight. We develop expressions for the resultant array factor, the locations for the beam directions of the subarrays and the half power beam width of resulting beam. We show that the broadening factor is proportional to the square of number of subarrays and the final array can be designed to have less than a 3 dB ripple in the passband.

24 citations

Cites background from "LTE-advanced: next-generation wirel..."

  • ...The current close-to-capacity system designs in current 3G/4G cellular standards, such as LTE-A, make it extremely difficult to meet the ever increasing demands of higher data rate communication with limited spectrum below 3 GHz [2, 3]....

    [...]

  • ...[10] K. Ramachandran, N. Prasad, K. Hosoya, K. Maruhashi, S. Rangarajan, “Adaptive Beamforming for 60 GHz Radios: Challenges and Preliminary Solutions,” Proceedings of the 2010 ACM international workshop on mmWave communications: from circuits to networks (mmCom '10), pg.33-38, Sep. 2010 [11] Lakkis, “Multi-resolution beamforming based on codebooks in MIMO systems”, US Patent....

    [...]

  • ...[6] C. Doan, S. Emami, A. Niknejad, R. Brodersen, "Millimeter-wave CMOS design," IEEE Journal of Solid-State Circuits, vol.40, no.1, pg. 144- 155, Jan. 2005 [7] M. Tabesh, J. Chen, C. Marcu, L.Kong, S. Kang, E. Alon, A. Niknejad, “A 65nm CMOS 4-Element Sub-34mW/Element 60GHz Phased Array Transceiver,” IEEE International Solid-State Circuits Conference (ISSCC), pg. 12-14, Mar. 2011 [8] I. Lakkis, S. Kato, S. Yong, P. Xia, “mmWave Multi-Resolution Beamforming,” IEEE 802.15-08-0182-00-003c, Jan. 2008 [9] J.Wang, Z. Lan, C. Pyo, T. Baykas, C.Sum, A. Rahman, R. Funada, F. Kojima, I. Lakkis, H. Harada, S. Kato, "Beam Codebook Based Beamforming Protocol for Multi-Gbps Millimeter-Wave WPAN Systems," IEEE Global Telecommunications Conference, 2009, pg.1-6....

    [...]

  • ...But, recently, there has been an increased interest in using mmWave frequencies for short range nonline-of-sight (NLOS) communication with multi-Gb/s data rates, especially at 60 GHz [4]....

    [...]

  • ...US 2009/0232245 A1, Sep. 2009 [12] C. Kerce, G. Brown, M. Mitchell, "Phase-Only Transmit Beam Broadening for Improved Radar Search Performance," IEEE Radar Conference, pg.451-456, Apr. 2007 [13] H. Lebret, S. Boyd, "Antenna array pattern synthesis via convex optimization," IEEE Transactions on Signal Processing, vol.45, no.3, pg.526-532, Mar. 1997 [14] G. Kautz, "Phase-only shaped beam synthesis via technique of approximated beam addition," IEEE Transactions on Antennas and Propagation, vol.47, no.5, pg.887-894, May 1999 [15] G. Shaw and R, Dybdal, "Beam broadening for active aperture antennas," IEEE Antennas and Propagation Society International Symposium, pp.134-137 vol.1, Jun 1989 [16] H. Krishnaswamy and H. Hashemi, “Integrated Beamforming Arrays,” in “mm-Wave Silicon Technology: 60 GHz and Beyond”, Springer, Jan. 2008...

    [...]

Proceedings Article•DOI•
Detecting if LTE is the Bottleneck with BurstTracker

[...]

Arjun Balasingam1, Manu Bansal1, Rakesh Misra, Kanthi Nagaraj1, Rahul Tandra, Sachin Katti1, Aaron Schulman2 •
Stanford University1, University of California, San Diego2
05 Aug 2019
TL;DR: In this article, the authors present a tool that developers can use to detect if the LTE downlink is the bottleneck for their applications by detecting if a user's downlink queue runs empty during download.
Abstract: We present BurstTracker, the first tool that developers can use to detect if the LTE downlink is the bottleneck for their applications. BurstTracker is driven by our discovery that the proprietary LTE downlink schedulers running on LTE base stations allocate resources to users in a way that reveals if a user's downlink queue runs empty during a download. We demonstrate that BurstTracker works across Tier-1 cellular providers and across a variety of network conditions. We also present a case study that shows how application developers can use this tool in practice. Surprisingly, with BurstTracker, we find that the LTE downlink may not be the bottleneck for video streaming on several Tier-1 providers, even during peak hours at busy locations. Rather, transparent TCP middleboxes deployed by these providers lead to downlink underutilization, because they force Slow-Start Restart. With a simple workaround, we improve video streaming bitrate on busy LTE links by 35%.

24 citations

Proceedings Article•
Compact router transceiver architecture for carrier aggregation systems

[...]

Chang-Ming Lai, Je-Kuan Jau, Ping-Hsun Wu, Jian-Yu Li
15 Dec 2011
TL;DR: In this paper, a transceiver architecture which adopts router structure in the RF path is described, where each RF path can be assigned with different number of carriers according to the corresponding requirements for each band to reduce hardware overhead.
Abstract: To meet the IMT-Advance technical requirement, both 3GPP LTE-Advanced and IEEE 802.16m include carrier aggregation as one of the key RF technologies. Carrier aggregation uses several carriers with narrow bandwidth which will be combined in the upper layer for high data rate transmission. These carriers can be either adjacent to each other or in different bands. This work describes a transceiver architecture which adopts router structure in the RF path. In the proposed architecture, each RF path can be assigned with different number of carriers according to the corresponding requirements for each band to reduce hardware overhead. The proposed architecture is simulated with Agilent ADS and emulated with hardware for further validation.

24 citations

Journal Article•DOI•
Resource scheduling in downlink LTE-advanced system with carrier aggregation

[...]

Le-xiang Lin1, Yuanan Liu1, Fang Liu1, Gang Xie1, Kai-ming Liu1, Xin-yang Ge1 •
Beijing University of Posts and Telecommunications1
01 Feb 2012-The Journal of China Universities of Posts and Telecommunications
TL;DR: An improved proportional fair (PF) scheduling algorithm base on INS is proposed, which design a weigh factor which is related with the number of the carriers and the percentage of LTE users and can effectively enhance the throughput of LTE Users and improve the system fairness.

24 citations

References
More filters
Proceedings Article•DOI•
Overview of UMTS Air-Interface Evolution

[...]

Brian K. Classon1, Kevin L. Baum1, Vijay Nangia1, R. Love, Yakun Sun, R. Nory, K. Stewart, Arunabha Ghosh, Rapeepat Ratasuk, Weimin Xiao, Jun Tan •
Motorola1
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

Proceedings Article•DOI•
On UMTS-LTE Physical Uplink Shared and Control Channels

[...]

A.D. Dabbagh1, Rapeepat Ratasuk1, A. Ghosh•
Motorola1
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]....

    [...]

Related Papers (5)
A survey on 3GPP heterogeneous networks

[...]

16 Jun 2011-IEEE Wireless Communications
Aleksander Damnjanovic, J. Montojo, Yongbin Wei, Ji Tingfang, Tao Luo, Madhavan Srinivasan Vajapeyam, Taesang Yoo, Osok Song, Durga Prasad Malladi 
LTE: the evolution of mobile broadband

[...]

01 Apr 2009-IEEE Communications Magazine
David Astely, Erik Dahlman, Anders Furuskär, Ylva Jading, Magnus Lindström, Stefan Parkvall 
Cooperative diversity in wireless networks: Efficient protocols and outage behavior

[...]

01 Dec 2004-IEEE Transactions on Information Theory
J.N. Laneman, David Tse, Gregory W. Wornell
Enhanced intercell interference coordination challenges in heterogeneous networks

[...]

16 Jun 2011-IEEE Wireless Communications
David Lopez-Perez, Ismail Guvenc, Marios Kountouris, Tony Q. S. Quek, Jie Zhang 
A simple transmit diversity technique for wireless communications

[...]

01 Oct 1998-IEEE Journal on Selected Areas in Communications
Siavash Alamouti
Trending Questions (1)
What is the difference between LTE Home Internet and FIOS?

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.

See answers from 10 other papers