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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01 Jan 2020
TL;DR: This paper provides a comprehensive overview of the state-of-the-art resource management scenarios in LTE-U systems, including single small cell base station (SBS), multiple SBSs, device-to-device networks, vehicular networks, and unmanned aerial vehicle (UAV) systems.
Abstract: With the tremendous growth in mobile data traffic, wireless cellular networks are facing a rigorous challenge to increase network capacity. Despite that many advanced technologies are used, the shortage of spectrum resource is still the main bottleneck for capacity enhancement. To address the challenge, the cellular networks have been motivated to seek for more fruitful radio spectra. Amongst many others, the unlicensed 5 GHz spectrum is a promising candidate due to its low channel attenuation, large available bandwidth, and easy to utilize. Therefore, the innovative technology of long-term evolution (LTE) using the unlicensed spectrum, known as LTE-Unlicensed (LTE-U), has been widely investigated as a promising means to increase the data rate of cellular networks. The unique characteristics of the unlicensed spectrum bring new challenges to resource management in the LTE-U system. During the last few years, there have been a lot of resource management designs for the newly-born but vigorous LTE-U technologies. This paper provides a comprehensive overview of the state-of-the-art resource management scenarios in LTE-U systems, including single small cell base station (SBS), multiple SBSs, device-to-device (D2D) networks, vehicular networks, and unmanned aerial vehicle (UAV) systems. The future research issues of resource management in LTE-U for 5G are also outlined.
19 citations
Cites background from "LTE-advanced: next-generation wirel..."
...Enhanced longterm evolution (LTE), also known as LTE-Advanced (LTEA) [2], has been developed by the third generation partnership project (3GPP) to provide significantly higher data rates and better user experience through many cutting-edge technologies, such as massive multiple-input multiple-output (MIMO) [3], [4], carrier aggregation (CA) [5], full-duplex (FD) communications [6], and device-to-device (D2D) communications [7], [8]....
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25 Sep 2012
TL;DR: A system-level simulator for evaluating performance of D2D communication underlaying cellular networks is developed and it can be noticed that D1D communication reusing uplink resources achieves better performance than that reusing downlink ones.
Abstract: Device-to-device (D2D) communication enables mobile devices to directly communicate with each other without help of infrastructure and to reuse radio resources of cellular networks. In case that cellular and D2D user equipments (UEs) reuse the radio resources, interference between them may degrade their performance. Therefore, interference between cellular and D2D UEs should be analyzed and coordinated to avoid performance degradation of the networks. In this paper, we develop a system-level simulator for evaluating performance of D2D communication underlaying cellular networks. The simulator consists of five functional modules and operates with event-driven simulation paradigm. We adopt a graphical user interface (GUI) to facilitate controlling the simulator and observing the results in execution of simulation. Utilizing the simulator, we analyze interference between cellular and D2D UEs for two cases of interference scenarios. From the results, we can notice that D2D communication reusing uplink resources achieves better performance than that reusing downlink ones.
19 citations
Cites background from "LTE-advanced: next-generation wirel..."
...In case that cellular and D2D user equipments (UEs) reuse the radio resources, interference between them may degrade their performance....
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TL;DR: Two deep learning (DL) based receiver schemes in uplink multiple-input multiple-output (MIMO) systems are proposed which can achieve optimal BER performance in low-dimensional MIMO systems, while the model- driven scheme can be trained with fewer trainable parameters and outperforms the data-driven scheme in high-dimension M IMO systems.
Abstract: In this paper, we propose two deep learning (DL) based receiver schemes in uplink multiple-input multiple-output (MIMO) systems. In the first scheme, we design a pilot-assisted MIMO receiver using a data-driven full connected neural network. This data-driven receiver can recover transmitted signal directly in an end-to-end manner without explicitly estimating channel. In the second scheme, we adopt a model-driven network which combines communication knowledge with DL. The model-driven scheme divides the MIMO receiver into channel estimation subnet and signal detection subnet, and each subnet is composed of a traditional solution as initialization and a DL network to further improve the accurate. The simulation results show that both of the two schemes achieve better bit error ratio (BER) performance than traditional methods. In particular, the data-driven scheme can achieve optimal BER performance in low-dimensional MIMO systems, while the model-driven scheme can be trained with fewer trainable parameters and outperforms the data-driven scheme in high-dimension MIMO systems.
19 citations
Cites background from "LTE-advanced: next-generation wirel..."
...s1 = −1− j⇔ u1 = [0, 0], s2 = −1+ j⇔ u2 = [0, 1], s3 = 1− j⇔ u3 = [1, 0], s4 = 1+ j⇔ u4 = [1, 1], (11)...
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...To solve the problem of spectrum resources scarcity and increasing throughput requirements, multiple-input multipleoutput (MIMO) has become one of the key technologies in the future network communication systems [1]–[4]....
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...The received pilot signal yp = [yp[1], ....
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..., yp[Np]] ∈ Cn×Np and the received data signal yd = [yd [1], ....
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TL;DR: This work proposes a method for orthogonal frequency division multiplexing (OFDM)-based 1024- and 4096-QAM transmission with soft-decision Viterbi decoding with impact on 5G mobile systems and provides an effective solution for introducing higher-order modulation schemes in 5G and beyond.
Abstract: Fifth-generation (5G) mobile systems are a necessary step toward successfully achieving further increases in data rates. As the use of higher-order quadrature amplitude modulation (QAM) is expected to increase data rates within a limited bandwidth, we propose a method for orthogonal frequency division multiplexing (OFDM)-based 1024- and 4096-QAM transmission with soft-decision Viterbi decoding for use in 5G mobile systems. Through evaluation of the transmission performance of the proposed method over multipath fading channels using link-level simulations, we determine the bit error rate (BER) performance of OFDM-based 1024- and 4096-QAM as a function of coding rate under two multipath fading channel models: extended pedestrian A (EPA) and extended vehicular A (EVA). We also demonstrate the influence of phase error on OFDM-based 1024- and 4096-QAM and clarify the relationship between phase error and the signal-to-noise ratio (SNR) penalty required to achieve a BER of 1 × 10−2. This work provides an effective solution for introducing higher-order modulation schemes in 5G and beyond.
19 citations
07 Apr 2013
TL;DR: It is demonstrated how an entirely passive, external observer can detect if and when a person is using Skype, and it is further demonstrated that this detection ability remains even when Skype traffic is interleaved with confounding simultaneous traffic such as BitTorrent.
Abstract: This paper presents a mechanism for inferring user behaviour from encrypted wireless network activity. Aside from being within range, this mechanism operates without any level of network access, and without the need to break any encryption. It demonstrates how an entirely passive, external observer can detect if and when a person is using Skype. It is further demonstrated that this detection ability remains even when Skype traffic is interleaved with confounding simultaneous traffic such as BitTorrent. The metrics utilised by the detection process are a consequence of efficient data transfer. It is reasonable to believe that similar methods would be effective on the majority of modern wireless communications, and not specific to the protocols underlying the demonstration. The approach shown challenges the assumption that secure cryptography means secure information and adaptations of the mechanism used may help guide the analysis of increasingly large volumes of encrypted data.
18 citations
Cites background from "LTE-advanced: next-generation wirel..."
...11) networks employed by home users and businesses alike, but also includes technology such as LTE that will soon become a global standard for data access via mobile phone networks [1]....
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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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