Mobility Based MIMO Link Adaptation in LTE-Advanced Cellular Networks
04 Nov 2010-pp 235-241
TL;DR: A signal-to-noise-ratio(SNR) cum mobility based MIMO/MCS link adaptation to enhance the overall performance of the LTE downlink is proposed.
Abstract: As the demand for mobile broadband services are growing, cellular networks are heading towards their fourth generation (4G). Long Term Evolution - Advanced (LTE-A) is emerging as a major candidate for 4G cellular networks. MIMO technology combined with OFDMA is a major technological change in 4G compared to their 3G counterparts. However various MIMO configurations and modulation/coding schemes(MCS) need to be carefully tuned to derive the promised gains of MIMO technology. In this paper we evaluate the performance of different MIMO configurations and MCSs in the downlink of LTE-based cellular networks. We propose a signal-to-noise-ratio(SNR) cum mobility based MIMO/MCS link adaptation to enhance the overall performance of the LTE downlink.
Citations
More filters
[...]
TL;DR: This paper presents a novel LTE-based solution to support high throughput and continuous multimedia services for high speed train passengers based on a Cell Array that smartly organizes the cells along a railway, together with a femto cell service that aggregates traffic demands within individual train cabins.
Abstract: The recent advent of high speed trains introduces new mobility patterns in wireless environments. The LTE-A (Long Term Evolution of 3GPP - Advanced) networks have largely tackled the Doppler effect problem in the physical layer and are able to keep wireless service with 100Mpbs throughput within a cell in speeds up to 350 km/h. Yet the much more frequent handovers across cells greatly increases the possibility of service interruptions, and the problem is prominent for multimedia communications that demand both high-throughput and continuous connections. In this paper, we present a novel LTE-based solution to support high throughput and continuous multimedia services for high speed train passengers. Our solution is based on a Cell Array that smartly organizes the cells along a railway, together with a femto cell service that aggregates traffic demands within individual train cabins. Given that the movement direction and speed of a high-speed train are generally known, our Cell Array effectively predicts the upcoming LTE cells in service, and enables a seamless handover that will not interrupt multimedia streams. To accommodate the extreme channel variations, we further propose a scheduling and resource allocation mechanism to maximize the service rate based on periodical signal quality changes. Our simulation under diverse network and railway/train configurations demonstrates that the proposed solution achieves much lower handover latency and higher data throughput, as compared to existing solutions. It also well resists to network and traffic dynamics, thus enabling uninterrupted quality multimedia services for passengers in high speed trains.
152 citations
Cites methods from "Mobility Based MIMO Link Adaptation..."
[...]
[...]
TL;DR: The goal is to discuss the fundamental concepts and relevant features of different radio resource management criteria, including water-filling, max–min fairness, proportional fairness, cross-layer optimization, utility maximization, and game theory, also including a toy example with two terminals to compare the performance of the different schemes.
Abstract: In this contribution, we present a survey on the radio resource allocation techniques in orthogonal frequency division multiplexing (OFDM) and orthogonal frequency division multiple access (OFDMA) systems. This problem goes back to 1960s and that is related to properly and efficiently allocate the radio resources, namely subcarriers and power. We start by overviewing the main open issues in OFDM. Then, we describe the problem formulation in OFDMA, and we review the existing solutions to allocate the radio resources. The goal is to discuss the fundamental concepts and relevant features of different radio resource management criteria, including water-filling, max–min fairness, proportional fairness, cross-layer optimization, utility maximization, and game theory, also including a toy example with two terminals to compare the performance of the different schemes. We conclude the survey with a review of the state-of-the-art in resource allocation for next-generation wireless networks, including multicellular systems, cognitive radio, and relay-assisted communications, and we summarize advantages and common problems of the existing solutions available in the literature. The distinguishing feature of this contribution is a tutorial-style introduction to the fundamental problems in this area of research, intended for beginners on this topic.
50 citations
Cites background from "Mobility Based MIMO Link Adaptation..."
[...]
[...]
01 Jan 2012
TL;DR: The paper provides a higher level overview of LTE-Advanced, which includes carrier aggregation for efficient spectrum use, MIMO techniques for multiple signal transmissions and receptions, relaying and heterogeneous deployment strategy.
Abstract: The higher peak data rates for mobile user are in demand. Audio/Video streaming, online conferences, and social media services are becoming the necessity of life. In order to fulfil the sheer amount of data need of users, robust and efficient wireless technology is needed. LTE-Advanced, which is based on Rel-10 of ITU is the solution for future mobile wireless networks. It is the promising technology for future wireless broadband network based on Rel-8 of Long term Evolution (LTE). The paper provides a higher level overview of LTE-Advanced, which includes carrier aggregation for efficient spectrum use, MIMO techniques for multiple signal transmissions and receptions, relaying and heterogeneous deployment strategy. LTE-Advanced system will be the NXGN wireless technology for years to come.
19 citations
Cites background from "Mobility Based MIMO Link Adaptation..."
[...]
[...]
Patent•
[...]
TL;DR: In this paper, link adaptation in uplink grant-less-random access (RA) communications is discussed. But the authors focus on the uplink uplink and do not consider the non-link-based condition of the UE.
Abstract: Embodiments are provided for a scheme of link adaptation (LA) in uplink grant-less random access (RA) communications. The scheme includes changing a modulation and coding (MCS) of a user, instead of using a fixed MCS over time, as the user link, channel, or non-link conditions vary during the RA communications. In an embodiment, a transmission point (TP) receives from a UE a packet encoded using a MCS, and detects a condition associated with uplink measurements or other non-link based condition of the UE. The TP then initiates an upgrade or a downgrade of the MCS in accordance with the condition, and signals the UE indicating a second MCS as a result. The UE thus sends a second packet encoded using the second MCS. In another embodiment, the UE initiates the MCS change in accordance to detecting a link or non-link based condition, such as change of mobility.
17 citations
[...]
TL;DR: A novel semantic web application developed to deliver a collaborative tagging system for a digital on-line museum based on Formal Concept Analysis the extensible distributed data model to support collaborative tagging and its web services implementation.
Abstract: This paper reports a novel semantic web application developed to deliver a collaborative tagging system for a digital on-line museum. The key features of our application -- called the Virtual Museum of the Pacific -- concern the browsing and retrieval interface based on Formal Concept Analysis the extensible distributed data model to support collaborative tagging and its web services implementation.
10 citations
References
More filters
[...]
AT&T1
TL;DR: This paper presents a simple two-branch transmit diversity scheme that provides the same diversity order as maximal-ratio receiver combining (MRRC) with one transmit antenna, and two receive antennas.
Abstract: This paper presents a simple two-branch transmit diversity scheme. Using two transmit antennas and one receive antenna the scheme provides the same diversity order as maximal-ratio receiver combining (MRRC) with one transmit antenna, and two receive antennas. It is also shown that the scheme may easily be generalized to two transmit antennas and M receive antennas to provide a diversity order of 2M. The new scheme does not require any bandwidth expansion or any feedback from the receiver to the transmitter and its computation complexity is similar to MRRC.
13,447 citations
[...]
TL;DR: This paper addresses digital communication in a Rayleigh fading environment when the channel characteristic is unknown at the transmitter but is known (tracked) at the receiver with the aim of leveraging the already highly developed 1-D codec technology.
Abstract: This paper addresses digital communication in a Rayleigh fading environment when the channel characteristic is unknown at the transmitter but is known (tracked) at the receiver. Inventing a codec architecture that can realize a significant portion of the great capacity promised by information theory is essential to a standout long-term position in highly competitive arenas like fixed and indoor wireless. Use (n T , n R ) to express the number of antenna elements at the transmitter and receiver. An (n, n) analysis shows that despite the n received waves interfering randomly, capacity grows linearly with n and is enormous. With n = 8 at 1% outage and 21-dB average SNR at each receiving element, 42 b/s/Hz is achieved. The capacity is more than 40 times that of a (1, 1) system at the same total radiated transmitter power and bandwidth. Moreover, in some applications, n could be much larger than 8. In striving for significant fractions of such huge capacities, the question arises: Can one construct an (n, n) system whose capacity scales linearly with n, using as building blocks n separately coded one-dimensional (1-D) subsystems of equal capacity? With the aim of leveraging the already highly developed 1-D codec technology, this paper reports just such an invention. In this new architecture, signals are layered in space and time as suggested by a tight capacity bound.
6,728 citations
[...]
TL;DR: Among the possible subcarrier mapping approaches, it is found that localizedFDMA (LFDMA) with channel-dependent scheduling (CDS) results in higher throughput than interleaved FDMA (JFDMA), however, the PARR performance of IFDMA is better than that of LFDMA.
Abstract: Single carrier frequency division multiple access (SC FDMA), a modified form of orthogonal FDMA (OFDMA), is a promising technique for high data rate uplink communications in future cellular systems. SC-FDMA has similar throughput performance and essentially the same overall complexity as OFDMA. A principal advantage of SC-FDMA is the peak-to-average power ratio (PARR), which is lower than that of OFDMA. SC FDMA is currently a strong candidate for the uplink multiple access scheme in the long term evolution of cellular systems under consideration by the third generation partnership project (3GPP). In this paper, we give an overview of SC-FDMA. We also analyze the effects of subcarrier mapping on throughput and PARR. Among the possible subcarrier mapping approaches, we find that localized FDMA (LFDMA) with channel-dependent scheduling (CDS) results in higher throughput than interleaved FDMA (JFDMA). However, the PARR performance of IFDMA is better than that of LFDMA. As in other communications systems there are complex tradeoffs between design parameters and performance in an SC-FDMA system
1,282 citations
[...]
TL;DR: This letter describes the SISO APP module that updates the APP corresponding to the input and the output bits, of a code, and shows how to embed it into an iterative decoder for a new hybrid concatenation of three codes, to fully exploit the benefits of the proposed S ISO APP module.
Abstract: Concatenated coding schemes consist of the combination of two or more simple constituent encoders and interleavers. The parallel concatenation known as "turbo code" has been shown to yield remarkable coding gains close to theoretical limits, yet admitting a relatively simple iterative decoding technique. The recently proposed serial concatenation of interleaved codes may offer superior performance to that of turbo codes. In both coding schemes, the core of the iterative decoding structure is a soft-input soft-output (SISO) a posteriori probability (APP) module. In this letter, we describe the SISO APP module that updates the APP's corresponding to the input and the output bits, of a code, and show how to embed it into an iterative decoder for a new hybrid concatenation of three codes, to fully exploit the benefits of the proposed SISO APP module.
606 citations
[...]
TL;DR: This work investigates the use of space-time coding in OFDM-based broadband systems where both spatial and frequency diversity are available and derives the design criteria for space-frequency codes and provides simulation results studying the influence of delay spread, propagation parameters, and antenna spacing.
Abstract: Space-time coding for fading channels is a communication technique that realizes the diversity benefits of multiple transmit antennas. Previous work in this area has focused on the narrowband flat fading case where spatial diversity only is available. We investigate the use of space-time coding in OFDM-based broadband systems where both spatial and frequency diversity are available. We consider a strategy which basically consists of coding across OFDM tones and is therefore called space-frequency coding. For a spatial broadband channel model taking into account physical propagation parameters and antenna spacing, we derive the design criteria for space-frequency codes and we show that space-time codes designed to achieve full spatial diversity in the narrowband case will in general not achieve full space-frequency diversity. Specifically, we show that the Alamouti (see IEEE J. Sel. Areas Comm., vol.16, p.1451-58, 1998) scheme across tones fails to exploit frequency diversity. For a given set of propagation parameters and given antenna spacing, we establish the maximum achievable diversity order. Finally, we provide simulation results studying the influence of delay spread, propagation parameters, and antenna spacing on the performance of space-frequency codes.
498 citations
Related Papers (5)
[...]
[...]
[...]
[...]