The Experts below are selected from a list of 945 Experts worldwide ranked by ideXlab platform

Kwang Soon Kim - One of the best experts on this subject based on the ideXlab platform.

  • ICUFN - User Detection Performance Analysis for Grant-Free Uplink Transmission in Large-Scale Antenna Systems
    2018 Tenth International Conference on Ubiquitous and Future Networks (ICUFN), 2018
    Co-Authors: Jonghyun Kim, Kyung Lin Ryu, Kwang Soon Kim
    Abstract:

    In this paper, user detection performance of a grant-free uplink transmission in a large scale antenna system is analyzed, in which a general grant-free multiple access is considered as the system model and Zadoff-Chu Sequence is used for the uplink pilot. The false alarm probabilities of various user detection schemes under the target detection probabilities are evaluated.

  • Generalized Cross-Correlation Properties of Chu Sequences
    IEEE Transactions on Information Theory, 2012
    Co-Authors: Jae Won Kang, Younghoon Whang, Kwang Soon Kim
    Abstract:

    In this paper, detailed cross-correlation properties for Chu Sequences are investigated. All possible values of the cross-correlation function of Chu Sequences are derived for any given Sequence length and lag, and the maximum magnitude distribution function ρN(x), which is defined as the number of all Chu Sequence pairs with length-N whose maximum magnitude of the cross-correlation function is √Nx, is obtained. Also, good lower and upper bounds on the maximum number of available Chu Sequences and a construction algorithm for the corresponding partial Chu Sequence set are proposed when the maximum magnitude of the cross-correlation among the Sequences is constrained. Numerical examples show that the proposed bounds are quite tight and the proposed construction algorithm is near-optimal up to fairly large value of N.

  • optimal pilot Sequence design based on Chu Sequences for multi cell environments
    The Journal of Korean Institute of Communications and Information Sciences, 2009
    Co-Authors: Jae Won Kang, Duho Rhee, Ilmu Byun, Kwang Soon Kim
    Abstract:

    In this paper, the channel estimation and pilot Sequence design technique of multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems in multi-cell environments are studied for situations in which the inter cell interference (ICI) is the dominant channel impairment. We design pilot Sequence aiming at minimizing mean square error and propose the channel estimation technique correspond to the designed pilot Sequences. The proposed pilot Sequences employ the Sequences with good correlation properties such as Chu Sequence and through simulations, it is shown that channel estimation algorithm using designed pilot Sequence is effective for mitigating the ICI.

Kristo Wenjie Yang - One of the best experts on this subject based on the ideXlab platform.

  • analysis of the frequency offset effect on zadoff Chu Sequence timing performance
    IEEE Transactions on Communications, 2014
    Co-Authors: Michael Mao Wang, Kristo Wenjie Yang
    Abstract:

    Zadoff-Chu (ZC) Sequences have been used as synchronization Sequences in modern wireless communication systems, replacing the conventional pseudorandom noise Sequences due to their perfect autocorrelation properties. We first study the problem of ambiguity between a timing offset and a frequency offset, which arises when a ZC Sequence is used as a synchronization signal. We then show how a frequency offset can impair the timing property of a ZC Sequence, causing irreducible timing errors. An analytical framework, particularly the timing spectrum, is developed, which fully characterizes a ZC Sequence's timing properties and its fundamental limitations as a time synchronization Sequence in the presence of a frequency offset between the transmitter and the receiver. This analytical framework provides a powerful analytical tool for timing signal design and performance analysis of ZC Sequences.

  • Analysis of the Frequency Offset Effect on Zadoff-Chu Sequence Timing Performance
    arXiv: Networking and Internet Architecture, 2014
    Co-Authors: Min Hua, Kristo Wenjie Yang, Michael Mao Wang, Kingsley Jun Zou
    Abstract:

    Zadoff-Chu (ZC) Sequences have been used as synchronization Sequences in modern wireless communication systems, replacing the conventional pseudo-random noise (PN) Sequences due to their perfect autocorrelation properties. We first study the ambiguity problem between a timing offset and a frequency offset when a ZC Sequence is used as a synchronization signal. We show how a frequency offset can impair the timing property of a ZC Sequence, causing irreducible timing errors. An analytical framework is developed, which completely characterizes a ZC Sequence's timing behavior and its fundamental limitation as a synchronization Sequence in the presence of a frequency offset between the transmitter and the receiver.

  • Analysis of the Frequency Offset Effect on Zadoff–Chu Sequence Timing Performance
    IEEE Transactions on Communications, 2014
    Co-Authors: Min Hua, Mao Wang, Kristo Wenjie Yang, Kingsley Jun Zou
    Abstract:

    Zadoff-Chu (ZC) Sequences have been used as synchronization Sequences in modern wireless communication systems, replacing the conventional pseudorandom noise Sequences due to their perfect autocorrelation properties. We first study the problem of ambiguity between a timing offset and a frequency offset, which arises when a ZC Sequence is used as a synchronization signal. We then show how a frequency offset can impair the timing property of a ZC Sequence, causing irreducible timing errors. An analytical framework, particularly the timing spectrum, is developed, which fully characterizes a ZC Sequence's timing properties and its fundamental limitations as a time synchronization Sequence in the presence of a frequency offset between the transmitter and the receiver. This analytical framework provides a powerful analytical tool for timing signal design and performance analysis of ZC Sequences.

Yong-soo Cho - One of the best experts on this subject based on the ideXlab platform.

  • Cell ID and Angle of Departure Estimation for Millimeter-wave Cellular Systems in Line-of-Sight Dominant Conditions Using Zadoff-Chu Sequence Based Beam Weight
    Electronics, 2020
    Co-Authors: Yeong Jun Kim, Yong-soo Cho
    Abstract:

    Millimeter-wave (mmWave) bands is considered for fifth-generation (5G) cellular systems because abundant spectrum is available for mobile broadband communications. In mmWave communication systems, accurate beamforming is important to compensate for high attenuation in the mmWave frequency band and to extend the transmission range. However, with the existing beamformers in mmWave cellular systems, the mobile station (MS) cannot identify the source (base station; BS) of the received beam because there are many neighboring BSs transmitting their training signals, requiring a large overhead. This paper proposes a new beam weight generation method for transmitting (Tx) beamformers at the BS in mmWave cellular systems during a beam training period. Beam weights are generated for Tx beamformers at neighboring BSs, so that a mobile station (MS) can estimate the source (cell ID; CID) and angle of departure (AoD) for each BS in multi-cell environments. A CID and AoD estimation method for mmWave cellular systems in a line-of-sight (LOS) dominant condition is presented using the beam weights generated by Zadoff-Chu Sequence. A simulation is conducted in a LOS dominant condition to show that the performances of CID detection and AoD estimation are similar for both the proposed and conventional methods. In the conventional methods, the DFT-based beamforming weight is used for Tx beamformer at the BS and orthogonal matching pursuit (OMP) algorithm is used for AoD estimation at the MS. The proposed method significantly reduces the processing time (1.6–6.25%) required for beam training compared to the conventional method.

  • a cell search technique based on zadoff Chu Sequence for uac systems
    International Conference on Information and Communication Technology Convergence, 2019
    Co-Authors: Muhammad Asim, Yong-soo Cho
    Abstract:

    The concept of frequency reuse has been considered for underwater acoustic cellular (UAC) systems owing to the limited available bandwidth of acoustic channels. In a UAC system, an underwater equipment (UE) should detect the identity of the underwater base station (UBS) and synchronize to a serving UBS. In this paper, a cell search technique based on Zadoff-Chu Sequence (ZCS-CST) for UAC is proposed to detect the identity of UBS at the physical layer when Doppler effect is not significant.

  • ICTC - A Cell Search Technique Based on Zadoff-Chu Sequence for UAC Systems
    2019 International Conference on Information and Communication Technology Convergence (ICTC), 2019
    Co-Authors: Muhammad Asim, Yong-soo Cho
    Abstract:

    The concept of frequency reuse has been considered for underwater acoustic cellular (UAC) systems owing to the limited available bandwidth of acoustic channels. In a UAC system, an underwater equipment (UE) should detect the identity of the underwater base station (UBS) and synchronize to a serving UBS. In this paper, a cell search technique based on Zadoff-Chu Sequence (ZCS-CST) for UAC is proposed to detect the identity of UBS at the physical layer when Doppler effect is not significant.

  • efficient beam training technique for millimeter wave cellular communications
    Etri Journal, 2015
    Co-Authors: Bon Woo Ku, Dae Gen Han, Yong-soo Cho
    Abstract:

    In this paper, a beam ID preamble (BIDP) technique, where the beam ID is transmitted in the physical layer, is proposed for efficient beam training in millimeter-wave (mmWave) cellular communication systems. In order to facilitate beam ID detection in a multicell environment with multiple beams, the BIDP is designed such that the beam ID is mapped onto a Zadoff–Chu Sequence in association with its cell ID. By analyzing the correlation property of the BIDP, it is shown that multiple beams can be transmitted simultaneously with the proposed technique with minimal interbeam interference in a multicell environment, where beams have different time delays due to propagation delay or multipath channel delay. Through simulation with the spatial channel model (SCM), it is shown that the best beam pairs can be found with a significantly reduced processing time of beam training in the proposed technique.

Kingsley Jun Zou - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of the Frequency Offset Effect on Zadoff-Chu Sequence Timing Performance
    arXiv: Networking and Internet Architecture, 2014
    Co-Authors: Min Hua, Kristo Wenjie Yang, Michael Mao Wang, Kingsley Jun Zou
    Abstract:

    Zadoff-Chu (ZC) Sequences have been used as synchronization Sequences in modern wireless communication systems, replacing the conventional pseudo-random noise (PN) Sequences due to their perfect autocorrelation properties. We first study the ambiguity problem between a timing offset and a frequency offset when a ZC Sequence is used as a synchronization signal. We show how a frequency offset can impair the timing property of a ZC Sequence, causing irreducible timing errors. An analytical framework is developed, which completely characterizes a ZC Sequence's timing behavior and its fundamental limitation as a synchronization Sequence in the presence of a frequency offset between the transmitter and the receiver.

  • Analysis of the Frequency Offset Effect on Zadoff–Chu Sequence Timing Performance
    IEEE Transactions on Communications, 2014
    Co-Authors: Min Hua, Mao Wang, Kristo Wenjie Yang, Kingsley Jun Zou
    Abstract:

    Zadoff-Chu (ZC) Sequences have been used as synchronization Sequences in modern wireless communication systems, replacing the conventional pseudorandom noise Sequences due to their perfect autocorrelation properties. We first study the problem of ambiguity between a timing offset and a frequency offset, which arises when a ZC Sequence is used as a synchronization signal. We then show how a frequency offset can impair the timing property of a ZC Sequence, causing irreducible timing errors. An analytical framework, particularly the timing spectrum, is developed, which fully characterizes a ZC Sequence's timing properties and its fundamental limitations as a time synchronization Sequence in the presence of a frequency offset between the transmitter and the receiver. This analytical framework provides a powerful analytical tool for timing signal design and performance analysis of ZC Sequences.

Kaushik Mahata - One of the best experts on this subject based on the ideXlab platform.

  • Zadoff–Chu Sequence Design for Random Access Initial Uplink Synchronization in LTE-Like Systems
    IEEE Transactions on Wireless Communications, 2017
    Co-Authors: Mashud Hyder, Kaushik Mahata
    Abstract:

    A Zadoff–Chu (ZC) Sequence is uncorrelated with a non-zero cyclically shifted version of itself. However, this alone is insufficient to mitigate inter-code interference in LTE initial uplink synchronization. The performance of the state-of-the-art algorithms vary widely depending on the specific ZC Sequences employed. We develop a systematic procedure to choose the ZC Sequences that yield the optimum performance. It turns out that the procedure for ZC code selection in LTE standard is suboptimal when the carrier frequency offset is not small.

  • zadoff Chu Sequence design for random access initial uplink synchronization in lte like systems
    IEEE Transactions on Wireless Communications, 2017
    Co-Authors: Mashud Hyder, Kaushik Mahata
    Abstract:

    A Zadoff–Chu (ZC) Sequence is uncorrelated with a non-zero cyclically shifted version of itself. However, this alone is insufficient to mitigate inter-code interference in LTE initial uplink synchronization. The performance of the state-of-the-art algorithms vary widely depending on the specific ZC Sequences employed. We develop a systematic procedure to choose the ZC Sequences that yield the optimum performance. It turns out that the procedure for ZC code selection in LTE standard is suboptimal when the carrier frequency offset is not small.

  • Zadoff-Chu Sequence design for random access initial uplink synchronization.
    arXiv: Information Theory, 2016
    Co-Authors: Mashud Hyder, Kaushik Mahata
    Abstract:

    The autocorrelation of a Zadoff-Chu (ZC) Sequence with a non-zero cyclically shifted version of itself is zero. Due to the interesting property, ZC Sequences are widely used in the LTE air interface in the primary synchronization signal (PSS), random access preamble (PRACH), uplink control channel (PUCCH) etc. However, this interesting property of ZC Sequence is not useful in the random access initial uplink synchronization problem due to some specific structures of the underlying problem. In particular, the state of the art uplink synchronization algorithms do not perform equally for all ZC Sequences. In this work, we show a systematic procedure to choose the ZC Sequences that yield the optimum performance of the uplink synchronization algorithms. At first, we show that the uplink synchronization is a sparse signal recovery problem on an overcomplete basis. Next, we use the theory of sparse recovery algorithms and identify a factor that controls performance of the algorithms. We then suggest a ZC Sequence design procedure to optimally choose this factor. The simulation results show that the performance of most of the state of the art uplink synchronization algorithms improve significantly when the ZC Sequences are chosen by using the proposed technique.