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
More filters
01 Sep 2017
TL;DR: In this paper, the performance of the fiber-optic inband relaying in the presence of both self-interference and inter-cell interference is demonstrated and the design method for the proposed fiber- optic in band relaying is established.
Abstract: Relaying is a key technology used to improve cell-edge user throughput and/or provide wider coverage. We propose a new type of fiber-optic relaying, which is intended to extend the coverage to heavily shadowed areas. We established a design method for the proposed fiber-optic relaying in the presence of self- interference, which is the interference between backhaul and access links, when the backhaul and access links operate simultaneously at the same carrier frequency. In this paper, we demonstrate the performance of the fiber-optic inband relaying in the presence of both self-interference and inter-cell interference. The theoretical desired-to-undesired- signal ratio is investigated for both uplink and downlink using a specific layout model, as parameters of optical fiber length between relay node facing an eNB and paired relay node facing UE. Using these results, we validate the design method for the proposed fiber-optic inband relaying.
2 citations
01 Dec 2010
TL;DR: The theory of constant power water filling algorithm and how it can applied to maximize the capacity of a Rayleigh fading channel is described.
Abstract: The increasing demand for portable and mobile communication devices has made wireless communication an indispensable field of research. The performance of any wireless communication system is determined to a large extent by the characteristics of the channel. For the purpose of system design and development, it is advantageous to have knowledge of the characteristics of the channel. In this paper, we discuss the various channel models that are in use today. We also present an overview of the various estimation and equalization algorithms that are widely employed. We then present the results of the simulations of the various channel models, and the observations made from these simulations. Finally, we describe the theory of constant power water filling algorithm and how it can applied to maximize the capacity of a Rayleigh fading channel.
2 citations
Cites methods from "LTE-advanced: next-generation wirel..."
...In section III, we present an overview of the various estimation and equalization algorithms in use....
[...]
01 Jan 2013
TL;DR: An adaptive radio resource allocation for balancing loads between the UMTS and LTE/LTE-Advanced interfaces according to various interference and mobility environments is proposed and numerical results indicate that the proposed approach outperforms other approaches in fractional reward loss and system utilization.
Abstract: The UMTS and LTE/LTE-Advanced specifications have been proposed to offer high data rate for the forwarding link under high-mobility wireless communications. The keys include supporting multi-modes of various coding schemes (e.g., VSF-OFCDM, OFDM, OFDMA), multiple-input multiple-output, relay networks, etc. To balance loads among different communication interfaces is one of the most important issues that should be addressed for achieving efficient radio resource allocations. In a shared packet service, the 3GPP UMTS adopts the VSF-OFCDM interface to allocate orthogonal codes of an OVSF code tree in two-dimension (2D) spreading of the time and frequency domains. Conversely, although the LTE/LTE-Advanced interface offers a high data rate, it suffers from unbalanced loads and moderate reward. This paper thus proposes an adaptive radio resource allocation for balancing loads between the UMTS and LTE/LTE-Advanced interfaces according to various interference and mobility environments. Additionally, an adaptive multi-code allocation is proposed for the UMTS to minimize the bandwidth waste rate while guaranteeing quality of service. Numerical results indicate that the proposed approach outperforms other approaches in fractional reward loss and system utilization.
1 citations
TL;DR: The method how to calculate the physical layer communication rate matching in LTE communication system is proposed and is proved to be efficient and reliable to achieve the desired objective of high-speed and stable transmission of data in physical layer.
Abstract: The method how to calculate the physical layer communication rate matching in LTE communication system is proposed. The algorithm is based on the study of Turbo code transmission channel. After treatments of multiple modules such as bits collection, selection, transmission, block interleaver, and block cascade, the rates of streams are matched. The key algorithm is analyzed briefly, and then it elaborates the transmission channel and control information rate matching of convolutional coding specifically. The algorithm is proved to be efficient and reliable to achieve the desired objective of high-speed and stable transmission of data in physical layer.
1 citations
TL;DR: The obtained results show that the proposed scheme shows a better synthetic performance than the existing resource allocation schemes in consideration of the re-buffering-time ratios and QoE value of DASH clients and the fairness among non-DASH clients.
Abstract: In this paper, we propose a new resource allocation scheme for symbiosis of DASH clients and non-DASH clients (RASS) to provide seamless video streaming service to DASH clients and to guarantee fairness among non-DASH clients. In RASS, all the LTE downlink resource blocks are divided into two chunks by a KKT-conditions-based Resource-Division Controller (KCRDC). With the two divided chunks, the proposed scheme leads PFRA and KKT-conditions-based resource allocation scheme (KCRA) to allocate each chunk to non-DASH clients and DASH clients, respectively. PFRA allocates resource blocks with maintaining good trade-off between fairness and spectrum efficiency. On the other hand, KCRA allocates more resource blocks to DASH clients in the risk of re-buffering events to preferentially reduce the re-buffering-time ratios of the DASH clients. Finally, simulations are completed using the NS-3 (network simulator). The obtained results show that the proposed scheme shows a better synthetic performance than the existing resource allocation schemes in consideration of the re-buffering-time ratios and QoE value of DASH clients and the fairness among non-DASH clients.
1 citations
Cites methods from "LTE-advanced: next-generation wirel..."
...Abbreviations ARP: Allocating remaining PRBs; BSOP: Base station optimization; CDN: Content distribution network; CSRAS: Client-side rate-adaptation scheme; CQI: Channel quality information; DASH: Dynamic adaptive streaming over http; EVA: Extended vehicular a; ETU: Extended typical urban; FDASH: Fuzzy-logic-based rate-adaptation scheme; FDD: Frequency division duplexing; FLC: Fuzzy-logic-controller; HTTP: Hypertext transfer protocol; KCRA: KKT-conditions-based resource allocation scheme; KCRDC: KKT-conditions-based resource-division controller; KKT: Karush-Kuhn-Tucker; LTE: Long-term evolution; MCS: Modulation and coding scheme; MTRA: Maximum-throughput resource allocation; PFRA: Proportional fair resource allocation; PRB: Physical resource block; PUSCH: Physical uplink shared channel; RASS: Resource allocation scheme for symbiosis of DASH clients and non-DASH clients; RTP: Real-time transport protocol; SFTM: Segment-fetching time method; SVAA: Smooth-video adaptation algorithm; TTI: Transmission time interval; QoE: Quality of experience; UDP: User datagram protocol Acknowledgements This research was supported by the KIAT (Korea Institute for Advancement of Technology) grant funded by the Korea Government (MOTIE : Ministry of Trade Industry and Energy)....
[...]
...Then, the HTTP Get Requests are transferred to the base station via the uplink data channel (PUSCH) [27] of the LTE system....
[...]
References
More filters
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]....
[...]