MAC Layer Performance of Different Channel Estimation Techniques in UTRAN LTE Downlink

Martín‐Sacristán, David; Cabrejas, Jorge; Calabuig, Daniel; Monserrat, José F.

doi:10.1109/vetecs.2009.5073662

Cited by 8 publications

(6 citation statements)

References 9 publications

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“…Results conclude that the prediction solution has the ability to improve throughput when the time delay is less than 5ms. Wiener‐based prediction filters are also widely found in the literature as a strategy to overcome the channel estimation errors, . This solution has also been proposed for the UL .…”

Section: Literature Survey At a Glancementioning

confidence: 99%

“…When the difference is low, the LMS proposed strategy shows significant improvement; however, as it increases, the LMS solution degrades the instantaneous channel information. Results conclude that the prediction solution has the ability to improve throughput when the time delay is less than 5 ms. Wiener-based prediction filters are also widely found in the literature as a strategy to overcome the channel estimation errors, [10][11][12]. This solution has also been proposed for the UL [13,14].…”

Section: Literature Survey At a Glancementioning

confidence: 99%

See 1 more Smart Citation

Cubic spline extrapolation for uplink channel quality prediction in LTE‐A with carrier aggregation

Lema

García-Lozano²,

Ruíz³

2015

Trans. Emerging Tel. Tech.

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In the context of wireless communications, an accurate channel state information (CSI) is key for a correct radio resource management. In the uplink of Long Term Evolution Advanced (LTE-A), obtaining up-to-date CSI relies on user equipments (UEs), that send sounding signals throughout the available bandwidth. This procedure is quite challenging when considering the ever increasing bandwidth demands and the introduction of carrier aggregation. Information from many radio resource blocks becomes outdated and unreliable for scheduling operations. Besides, interference values are much more variant than the downlink due to changes in the position of interferers and their transmission power. This work proposes the introduction of cubic spline extrapolation to obtain a prediction horizon that allows extending the reliability of the channel quality evaluation along time. Though very high interference levels and variations thereof imply no gains, the mechanism succeeds with moderate interference, situation that can be provided by interference cancellation strategies.

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Section: Literature Survey At a Glancementioning

confidence: 99%

Section: Literature Survey At a Glancementioning

confidence: 99%

Cubic spline extrapolation for uplink channel quality prediction in LTE‐A with carrier aggregation

Lema

García-Lozano²,

Ruíz³

2015

Trans. Emerging Tel. Tech.

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“…As mentioned before, this channel estimation is performed using reference signals in LTE. In this simulator, several real channel estimators have been implemented [116]. Then, these real channel estimators allow to emulate the penalty on the performance in a real situation due to the channel estimation.…”

Section: -Channelmentioning

confidence: 99%

Broadcasting in 4G mobile broadband networks and its evolution towards 5G

Gaspar¹

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networks and its evolution towards 5GAls meus pares, als meus germans i a Clara. AbstractOne of the challenges of the mobile industry is to cope with the growth of mobile traffic demand expected for the next years, primarily driven by the increasing usage of mobile video services. Indeed, the existence of increasingly powerful terminals is encouraging the consumption of high-quality video content. Usually, video services are identified with linear Television (TV) and scheduled broadcast (point-to-multipoint (p-t-m)) distribution. However, the consumption of video content over mobile networks is different from traditional fixed TV because contents are mainly consumed on-demand with unicast point-to-point (p-t-p) connections. Then, the convergence of linear TV and on-demand content delivery represents a challenge that requires a combined broadcast/unicast transmission model. This dissertation addresses the use of broadcasting technologies for the provision of mobile multimedia services in Fourth Generation (4G) mobile broadband networks and beyond. Specifically, the dissertation focuses on the broadcast technology included in 4G Long Term Evolution (LTE) and LTE Advanced (LTE-A) networks, known as Evolved Multimedia Broadcast Multicast Services (eMBMS). It analyses the benefits of the eMBMS physical layer aspects regarding Multimedia Broadcast Multicast Services over Single Frequency Network (MBSFN) deployments and identifies the current limitations of eMBMS at physical layer by comparing with the broadcast technology of the other 4G mobile system, the IEEE 802.16m standard. Those limitations are the use of a dedicated carrier and Multiple-Input Multiple-Output (MIMO) techniques for broadcast transmissions. Our investigations employ a complete simulation platform including link-level and system-level simulations to evaluate the performance of broadcast transmissions in these real technologies.The research on eMBMS services is aimed at finding the optimum delivery of streaming and file download services focusing on the Radio Resource Management (RRM) problem and trade-off between Physical layer -Forward Error Correction (PHY-FEC) and Application Layer -Forward Error Correction (AL-FEC). Concerning streaming services, results show that the use of i ABSTRACT AL-FEC increases the coverage level and, then, the maximum service data rate. The gain due to AL-FEC is greater in scenarios with high mobility users, although, this gain is limited if low zapping times are desired. Regarding file delivery services, this dissertation analyses the duration of the transmission required to guarantee the correct file reception and the reduction in the mean throughput of unicast users with different delivery modes. They are the unicast delivery, the eMBMS delivery and a hybrid approach, which combines a first eMBMS delivery with a post-delivery error repair phase with unicast transmissions. Our results show that the hybrid delivery is the most efficient configuration in terms of file download time, although it further reduces unicast ...

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“…The LTE baselines are the transmit diversity modes SFBC for two antennas and FSTD for four antennas, with Quadrature Phase-Shift Keying (QPSK) modulation. Both coherent baselines consider a channel estimator based on a Wiener filtering in frequency and in time domain [79]. This channel estimator knows the frequency and time correlation of the channel, as well as the noise power, and uses the standardized LTE reference signals for channel estimation.…”

Section: Simulation Environmentmentioning

confidence: 99%

Distributed cooperative MIMO in beyond 2020 wireless networks.

Peñuelas¹

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Mobile communication systems are currently being developed with the aim of providing peak data rates up to 20 times higher to those of Long Term Evolution (LTE)-Advanced Release 10. However, this performance improvement is often far from being the experimented performance by all users, especially, for those users who are far from the base station. In this sense, there exists a consensus within the international scientific community on the fact that the best way to achieve the same quality for all users is with the use of heterogeneous networks composed of macrocells, microcells, femtocells, and relays.This dissertation addresses the use of mobile relays to provide service to users who are out-of-coverage or undergo low data rates as they are located at the cell-edge. Mobile relaying is a natural extension of the fixed relay in which users who are in the idle state could retransmit signals received from other transmitters to enhance signal quality and consequently data rates. The use of mobile relaying could make the data boost required by the future Fifth Generation (5G) affordable.Our investigations employ a simulation platform that includes link-level and system-level simulations. This dissertation focuses on proposing and evaluating new techniques that manage the use of the mobile relay in the new generation cellular networks. In particular, the dissertation studies mobile relaying from two complementary points of view.The first point of view investigates the mobile relay management at the network level through a signaling protocol known as Media Independent Handover (MIH). The main idea of the proposed mechanism is to use this signaling to connect the base station and the user in one of the following two manners. In the former, both entities are connected directly through the xG (x= 2, 3, 4, 5) wireless network. In the latter, there exists an xG connection between the base station and the mobile relay and another one between the mobile relay and the user through an IEEE 802.11 local wireless network. The investigations in this Thesis aim at finding a trade-off between using multiple mobile relays and reducing signaling overhead. i ABSTRACTThe second point of view deals with mobile relying integration at the air interface level. It consists in detecting, proposing, and evaluating new transmission techniques that solve the drawbacks derived from coherent detection. As with point-to-point systems, employing multiple antennas in a cooperative system can significantly improve the spectral efficiency of the systems with only one transmit antenna assuming that the channel state information is available at the receiver. However, performing a coherent detection in a network assisted by relays consumes much more resources than a point-to-point network since the coherent detection requires the channel estimation of source-relay, relaydestination, and source-destination links. In this Thesis, the proposed solution is to use transmission techniques that do not need the channel knowledge to perform the detection. ...

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MAC Layer Performance of Different Channel Estimation Techniques in UTRAN LTE Downlink

Cited by 8 publications

References 9 publications

Cubic spline extrapolation for uplink channel quality prediction in LTE‐A with carrier aggregation

Cubic spline extrapolation for uplink channel quality prediction in LTE‐A with carrier aggregation

Broadcasting in 4G mobile broadband networks and its evolution towards 5G

Distributed cooperative MIMO in beyond 2020 wireless networks.

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