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33
GFDM- Generalized Frequency Division Multiplexing Invited Paper
"... Abstract—This paper presents the GFDM system, a generalized digital multi-carrier transceiver concept. GFDM is based on traditional filter bank multi-branch multicarrier concepts which are now implemented digitally. Our GFDM approach exhibits some attractive features which are of particular importan ..."
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Abstract—This paper presents the GFDM system, a generalized digital multi-carrier transceiver concept. GFDM is based on traditional filter bank multi-branch multicarrier concepts which are now implemented digitally. Our GFDM approach exhibits some attractive features which are of particular importance for scenarios exhibiting high degrees of spectrum fragmentation. Spectrum fragmentation is a typical technical challenge of digital dividend use cases, exploiting spectrum white spaces in the TV UHF bands which are located in close proximity to allocated spectrum. Specifically, the GFDM features are a lower PAPR compared to OFDM, a ultra-low out-ofband radiation due adjustable Tx-filtering and last but not least a block-based transmission using cyclic prefix insertion and efficient FFT-based equalization. GFDM enables frequency and time domain multi-user scheduling comparable to OFDM and provides an efficient alternative for white space aggregation even in heavily fragmented spectrum regions. I.
Frequency-Domain Packet Scheduling for 3GPP LTE Uplink
"... Abstract—In this paper, we investigate the frequency-domain packet scheduling (FDPS) problem for 3GPP LTE Uplink (UL). Instead of studying a specific scheduling policy, we provide a unified approach to tackle this issue. First we formalize a general LTE UL FDPS problem which is suitable for various ..."
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Abstract—In this paper, we investigate the frequency-domain packet scheduling (FDPS) problem for 3GPP LTE Uplink (UL). Instead of studying a specific scheduling policy, we provide a unified approach to tackle this issue. First we formalize a general LTE UL FDPS problem which is suitable for various scheduling policies. Then we prove that the problem is MAX SNP-hard, which implies that approximation algorithms with constant approximation ratios are the best that we can hope for. Therefore we design two approximation algorithms, both of which have polynomial runtime. Subsequently, we analyze the two algorithms and find their approximation ratios. The first algorithm is easy to follow, since it is based on a simple greedy method. The second one is based on the local ratio technique and it can approximately solve the LTE UL FDPS problem with a approximation ratio of 2. I.
Carrier Frequency dependent Downlink Spectral Efficiency of Cellular LTE Deployments
"... Abstract—This paper explains a system level evaluation framework which allows performance assessment of cellular OFDMbased systems at different carrier frequencies. In the numerical examples we model the downlink transmission of an 3GPP LTE deployment. I. ..."
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Abstract—This paper explains a system level evaluation framework which allows performance assessment of cellular OFDMbased systems at different carrier frequencies. In the numerical examples we model the downlink transmission of an 3GPP LTE deployment. I.
A Comprehensive Analysis of LTE Physical Layer,” MSc
, 2010
"... as the 3 rd generation of mobile communication standards. LTE Release 8 describes a mobile communication standard which supports up to 300 Mbps of data transmission in downlink using the OFDM scheme as well as up to 75 Mbps throughput for uplink using the SC-FDMA modulation. In this thesis, an in-de ..."
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as the 3 rd generation of mobile communication standards. LTE Release 8 describes a mobile communication standard which supports up to 300 Mbps of data transmission in downlink using the OFDM scheme as well as up to 75 Mbps throughput for uplink using the SC-FDMA modulation. In this thesis, an in-depth study of LTE performance based on Release 8 is conducted for uplink and downlink under different scenarios. The main objective of this study is to investigate a comprehensive analysis of physical layer throughput of LTE Release8 based on standard parameters for different channel bandwidths, duplex schemes, antenna diversity and other scenarios. Our study of the FDD operation mode shows that the maximum throughput for downlink data is 299.122
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"... Long Term Evolution (LTE) represents the next step of the actual mobile communications standards, such as UMTS and GSM. Its main goal is to improve uplink and downlink throughput values up to 50 Mbps and 100 Mbps respectively. Another important point of this new standard is that uses scalable bandwi ..."
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Long Term Evolution (LTE) represents the next step of the actual mobile communications standards, such as UMTS and GSM. Its main goal is to improve uplink and downlink throughput values up to 50 Mbps and 100 Mbps respectively. Another important point of this new standard is that uses scalable bandwidth from 1.25 to 20 MHz that suits the needs of the different network operators that have different bandwidth allocations. It is also expected to improve spectral efficiency in 3G networks, allowing carriers to provide more data and voice services over a given bandwidth. The limited resources to transmit are an important fact to consider when the desire is to improve the speed of the transmissions. What this thesis proposes is different ways of sharing the available resources efficiently and also trying to not interfere in high manner the other transmissions. Since the scheduling algorithms are not fixed in any 3GPP standard the main goal of this thesis is to analyze and compare different algorithms to extract the one or the several methods that improve the allocation in terms of throughput.
TIMING-BASED LOCATION ESTIMATION FOR OFDM SIGNALS WITH APPLICATIONS IN LTE, WLAN AND WIMAX
, 2012
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"... Conference on Internet. AH-ICI 2009, pp. 1-5.. This material is posted here with ..."
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Conference on Internet. AH-ICI 2009, pp. 1-5.. This material is posted here with
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, 2014
"... This Open Access Dissertation is brought to you for free and open access by the Dissertations and Theses at ScholarWorks@UMass Amherst. It has ..."
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This Open Access Dissertation is brought to you for free and open access by the Dissertations and Theses at ScholarWorks@UMass Amherst. It has
Power Allocation for Joint Interweave and Underlay Cognitive Radio Systems with Arbitrary Input Distributions
"... Abstract-In the literature, the Gaussian input is assumed in power optimization algorithms. However, this assumption is unrealistic, whereas practical systems use Finite Symbol Alphabet (FSA) input, (e.g., M-QAM). In this paper, we consider the optimal power for joint interweave and underlay CR sys ..."
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Abstract-In the literature, the Gaussian input is assumed in power optimization algorithms. However, this assumption is unrealistic, whereas practical systems use Finite Symbol Alphabet (FSA) input, (e.g., M-QAM). In this paper, we consider the optimal power for joint interweave and underlay CR systems given FSA inputs. We formulated our problem as convex optimization and solved it through general convex optimization tools. We observed that the total SU transmit power is always less than the power budget and remains in interference limited region only over the considered distance range. Therefore, we rederive optimal power with interference constraint only in order to reduce the complexity of the algorithm by solving it analytically. Numerical results reveal that, for the considered distance range, the transmit power saving and the rate gain with the proposed algorithm is in the range 16 − 92% and 7 − 34%, respectively, depending on the modulation scheme (i.e., BPSK, QPSK and 16-QAM) used.
