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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16 Dec 2019
TL;DR: In this article, the authors proposed a Sub-array based Antenna Selection Scheme (SASS) for massive MIMO based on sub-array switching architecture which is beneficially helpful to achieve optimal throughput, energy efficiency and capacity.
Abstract: With rapidly increased throughput demand, operators are rapidly improving coverage and capacity with cost effective techniques in wireless communication network. Developments in technology enables advanced antenna system to be scalable across 5G and future wireless networks. Massive MIMO based advance antenna selection techniques provide powerful and affordable methods that are effective approaches for coverage and capacity of consumers. Prerequisites of an optimal communication system grow quickly, and therefore operators require more facilities to meet their needs. It is necessity to serve many operators and various devices at the same time in the integrated zone, while providing fast speed and consistent performance, makes it the boosting technology yard to meet the requirements of the 5G era. In this paper, we propose a Sub-array based Antenna Selection Scheme (SASS) for massive MIMO based on sub-array switching architecture which is beneficially helpful to achieve optimal throughput, energy efficiency and capacity. Moreover, SASS is cost effective technique which reduces the overall cost of system including computational, communication, and hardware impairments. We have validated our work using MATLAB and results are compared for spectral efficiency when number of antennas and Signal to noise ratio are varied. Results prove the dominance of SASS over counterparts.
1 citations
TL;DR: A stable transmission scheme for the A/G MIMO transmission is proposed with an open-loop calibrated channel estimation scheme based on navigation filtering to offer a more accurate CSI estimation and an adaptive precoding schemebased on the correlation coefficient for stable transmission.
Abstract: Due to the high flight speed of the aircraft and long range to access the ground station (GS), the channel state information (CSI) is not accurately obtained by direct feedback from the receiver to the transmitter. This makes it difficult to achieve stable transmission when the feedback codebook selection scheme is directly employed in the multiple-input multiple-output (MIMO) for the air-to-ground (A/G) communications. Therefore, in this paper, a stable transmission scheme for the A/G MIMO transmission is proposed to handle these issues. Two contributions are proposed: 1) an open-loop calibrated channel estimation scheme based on navigation filtering to offer a more accurate CSI estimation; and 2) an adaptive precoding scheme based on the correlation coefficient for stable transmission. The simulations confirm the validity and efficiency of the proposed schemes. For the 4 $\times$ 4 MIMO transmission, compared with the traditional scheme of a single antenna, the spectrum efficiency can be improved by 2 $\sim$ 4 times with a stable transmission.
1 citations
Cites background from "LTE-advanced: next-generation wirel..."
...communications, a Long-Term Evolution (LTE) system provides a stable MIMO transmission based on codebook selection to overcome the channel variation [3], i....
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DOI•
01 Jan 2016
TL;DR: A new approximate representation for the wireless fading channels is proposed and applied to facilitate accurate, asymptotic performance analysis for the energy detector across a variety of operating conditions including fading, antenna/cooperative diversity and interference.
Abstract: The exponential growth in the number of wireless broadband service users demands an enormous increase in the available communication bandwidth, which inherently translates into an increased demand for the radio frequency spectrum. Opportunistically accessing the unused portions of the spectrum requires sensing the availability of unused bands. In this thesis, non-coherent detectors such as the energy detector and its more generalized version, the p-norm detector, which offer low-cost low-complexity spectrum sensing are considered and comprehensive techniques for performance analyses are developed. To this end, a new approximate representation for the wireless fading channels is proposed and applied to facilitate accurate, asymptotic performance analysis for the energy detector across a variety of operating conditions including fading, antenna/cooperative diversity and interference. To address the analytical difficulty involved in spectrum sensing using the p-norm detector, several accurate analytical expressions are developed and utilized to comprehensively characterize the spectrum sensing performance in generalized fading channels and in fading channels with antenna diversity. To promote tractable spectrum sensing performance analysis for arbitrary sample sizes, five accurate approximations are introduced and investigated. In another comprehensive system setup, spectrum sensing performance of the p-norm detector under the cumulative effects of path-loss, fading, and a large number of randomly deployed interfering nodes is characterized by developing a comprehensive semi-analytical technique and extended to cooperative spectrum sensing.
1 citations
Cites background from "LTE-advanced: next-generation wirel..."
...networks, thus extending the wireless coverage and capacity [10]....
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...These bands could be particularly suited for dense deployment of small-cells [9] for significantly boosting the spectral efficiency of the traditional cellular systems [10]....
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08 Dec 2011
TL;DR: This paper demonstrates that the optimal wireless link quality based BMG partition and the associated quantization, time-fraction parameters can be computed by solving a series of convex objective minimization problems.
Abstract: In this paper we present a novel scheme for video quality maximization in the context of H.264 scalable video coding (SVC) based 4G wireless broadcast and multicast video transmission. A typical wireless multicast group comprises of multimedia clients with varying wireless link qualities. Thus, the conventional fair rate static video (FRSV) transmission scheme, which aims to achieve QoS fairness in multicast video transmission is rate and hence quality constrained by the BMG subscriber with the worst link capacity. Hence, we propose a novel rate partitioning based scalable video (RPSV) transmission framework to overcome this limitation. The proposed RPSV scheme optimally partitions the multicast group for transmission of the H.264 coded base and enhancement scalable video layers. This is based on the Medium Grain Scalability (MGS) feature for enhancement layer coding in H.264 SVC. We demonstrate that the optimal wireless link quality based BMG partition and the associated quantization, time-fraction parameters can be computed by solving a series of convex objective minimization problems. RPSV naturally leads to a significant enhancement in the net multicast group video quality by avoiding the rate bottleneck otherwise caused by the worst link user, while simultaneously resulting in QoS fairness by avoiding service starvation of the user with the poorest link quality. We compare the resulting video quality obtained from the proposed RPSV based quantization parameter adaptation paradigm with the performance of the simplistic FRSV scheme and demonstrate the superiority of the former.
1 citations
Cites background from "LTE-advanced: next-generation wirel..."
...I. INTRODUCTION A significant number of future mobile services envisaged in fourth generation (4G) LTE and WiMAX [1], [2] wireless networks are primarily based on reliable video transmission....
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01 Aug 2014
TL;DR: This work considers BLER of different precode methods, and finds that when applied to OFDM based massive MIMO, existing precoding methods would hardly work if applied to multiple resource blocks (RBs).
Abstract: Literatures on precoding for massive MIMO, one disruptive technology for enabling 5G, have been mainly about metrics such as capacity and peak-to-average reduction. But for practical systems, block error rate (BLER) is one essential parameter that decides whether the system can work properly. In this work, we consider BLER of different precoding methods, and find that when applied to OFDM based massive MIMO, existing precoding methods would hardly work if applied to multiple resource blocks (RBs). Then, we propose a precoding method that intends to minimize the inter-user interference over the subcarriers. Through numerical results, we show that with this method, precoding can now be performed on multiple RBs. Overall, we have shown that precoding analysis for massive MIMO still needs further careful investigations.
1 citations
Cites background from "LTE-advanced: next-generation wirel..."
...This can achieve very good performance for LTE/LTE-A systems, where the precoding is performed over multiple resource blocks (RBs) as a resource scheduling unit, since the number of multiplexing users is very small [10]....
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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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