The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform

Philip Schniter - One of the best experts on this subject based on the ideXlab platform.

  • max sinr isi ici shaping multicarrier communication over the doubly Dispersive Channel
    IEEE Transactions on Signal Processing, 2007
    Co-Authors: Sibasish Das, Philip Schniter
    Abstract:

    For communication over doubly Dispersive Channels, we consider the design of multicarrier modulation (MCM) schemes based on time-frequency shifts of prototype pulses. We consider the case where the receiver knows the Channel state and the transmitter knows the Channel statistics (e.g., delay spread and Doppler spread) but not the Channel state. Previous work has examined MCM pulses designed for suppression of inter-symbol/inter-carrier interference (ISI/ICI) subject to orthogonal or biorthogonal constraints. In doubly Dispersive Channels, however, complete suppression of ISI/ICI is impossible, and the ISI/ICI pattern generated by these (bi)orthogonal schemes can be difficult to equalize, especially when operating at high bandwidth efficiency. We propose a different approach to MCM pulse design, whereby a limited expanse of ISI/ICI is tolerated in modulation/demodulation and treated near-optimally by a downstream equalizer. Specifically, we propose MCM pulse designs that maximize a signal-to-interference-plus-noise ratio (SINR) which suppresses ISI/ICI outside a target pattern. In addition, we propose two low-complexity turbo equalizers, based on minimum mean-squared error and maximum likelihood criteria, respectively, that leverage the structure of the target ISI/ICI pattern. The resulting system exhibits an excellent combination of low complexity, low bit-error rate, and high spectral efficiency.

  • Max-SINR ISI/ICI-shaping multicarrier communication over the doubly Dispersive Channel
    IEEE Transactions on Signal Processing, 2007
    Co-Authors: Sibasish Das, Philip Schniter
    Abstract:

    For communication over doubly Dispersive Channels, we consider the design of multicarrier modulation (MCM) schemes based on time-frequency shifts of prototype pulses. We consider the case where the receiver knows the Channel state and the transmitter knows the Channel statistics (e.g., delay spread and Doppler spread) but not the Channel state. Previous work has examined MCM pulses designed for suppression of inter-symbol/inter-carrier interference (ISI/ICI) subject to orthogonal or biorthogonal constraints. In doubly Dispersive Channels, however, complete suppression of ISI/ICI is impossible, and the ISI/ICI pattern generated by these (bi)orthogonal schemes can be difficult to equalize, especially when operating at high bandwidth efficiency. We propose a different approach to MCM pulse design, whereby a limited expanse of ISI/ICI is tolerated in modulation/demodulation and treated near-optimally by a downstream equalizer. Specifically, we propose MCM pulse designs that maximize a signal-to-interference-plus-noise ratio (SINR) which suppresses ISI/ICI outside a target pattern. In addition, we propose two low-complexity turbo equalizers, based on minimum mean-squared error and maximum likelihood criteria, respectively, that leverage the structure of the target ISI/ICI pattern. The resulting system exhibits an excellent combination of low complexity, low bit-error rate, and high spectral efficiency.

  • Maximum-diversity affine precoding for the noncoherent doubly Dispersive Channel
    2007 IEEE 8th Workshop on Signal Processing Advances in Wireless Communications, 2007
    Co-Authors: Sung-jun Hwang, Philip Schniter
    Abstract:

    In this paper we characterize the maximally achievable diversity order for noncoherent block communication over the doubly Dispersive Channel, and propose affine precoders which facilitate such maximum-diversity reception. In fact, we show that, under mild Channel conditions, almost any affine pre-coder is sufficient to facilitate maximum-diversity reception, regardless of precoding rate. By "noncoherent," we mean that the Channel realization is unknown to both transmitter and receiver, and by "doubly Dispersive," we mean that the Channel exhibits both delay and Doppler spreading (i.e., the Channel has a time-varying nontrivial impulse response).

  • Communication Over the Doubly Dispersive Channel
    2007
    Co-Authors: Sibasish Das, Philip Schniter
    Abstract:

    For communication over doubly Dispersive Channels, we consider the design of multicarrier modulation (MCM) schemes based on time-frequency shifts of prototype pulses. We consider the case where the receiver knows the Channel state and the trans- mitter knows the Channel statistics (e.g., delay spread and Doppler spread) but not the Channel state. Previous work has examined MCM pulses designed for suppression of inter-symbol/inter-car- rier interference (ISI/ICI) subject to orthogonal or biorthogonal constraints. In doubly Dispersive Channels, however, complete sup- pression of ISI/ICI is impossible, and the ISI/ICI pattern gener- ated by these (bi)orthogonal schemes can be difficult to equalize, especially when operating at high bandwidth efficiency. We pro- pose a different approach to MCM pulse design, whereby a limited expanse of ISI/ICI is tolerated in modulation/demodulation and treated near-optimally by a downstream equalizer. Specifically, we propose MCM pulse designs that maximize a signal-to-interfer- ence-plus-noise ratio (SINR) which suppresses ISI/ICI outside a target pattern. In addition, we propose two low-complexity turbo equalizers, based on minimum mean-squared error and maximum likelihood criteria, respectively, that leverage the structure of the target ISI/ICI pattern. The resulting system exhibits an excellent combination of low complexity, low bit-error rate, and high spec- tral efficiency. Index Terms—Equalization, doubly Dispersive Channel, inter- carrier interference (ICI), inter-symbol interference (ISI), modu- lation, multicarrier, multipath, pulse-shape, time-varying Channel, turbo-equalization, wireless communications.

  • on doubly Dispersive Channel estimation for pilot aided pulse shaped multi carrier modulation
    Conference on Information Sciences and Systems, 2006
    Co-Authors: Philip Schniter
    Abstract:

    In this paper, we propose several methods for the pilot-aided estimation of significant ICI coefficients resulting from pulse-shaped multicarrier modulation (PS-MCM) over DD Channels. Specifically, we outline Wiener and reduced-rank (RR) Wiener estimation schemes that leverage statistical Channel structure, as well as deterministic least-squares (LS) schemes based on basis expansion modeling (BEM). We then report the results of a numerical study which suggests that RR Wiener estimation outperforms LS estimation based on polynomial and oversampled complex exponential BEM, even under significant statistical mismatch. In addition, the RR Wiener estimator is computationally cheaper than the LS-BEM techniques. These findings have implications on the practical design of PS-MCM Channel estimation schemes.

Dongmei Zhang - One of the best experts on this subject based on the ideXlab platform.

  • max sinr receiver for hmct systems over non stationary doubly Dispersive Channel
    URSI General Assembly and Scientific Symposium, 2014
    Co-Authors: Dongmei Zhang
    Abstract:

    In this paper, a maximizing Signal-to-Interference plus-Noise Ratio (Max-SINR) receiver for Hexagonal Multicarrier Transmission (HMCT) system over non-stationary doubly Dispersive (NSDD) Channel is proposed. The closed-form timing offset expression of the prototype pulse for the proposed Max-SINR HMCT receiver over NSDD Channel is derived. Simulation results show that the proposed Max-SINR receiver outperforms traditional projection scheme and obtains an approximation to the theoretical upper bound SINR performance within all the local stationarity regions (LSRs). Meanwhile, the SINR performance of the proposed Max-SINR HMCT receiver is robust to the estimation error between the estimated value and the real value of root mean square (RMS) delay spread.

  • on max sinr receivers for hmt systems over a doubly Dispersive Channel
    IEEE Transactions on Vehicular Technology, 2013
    Co-Authors: Dongmei Zhang
    Abstract:

    In this paper, a novel receiver for hexagonal multicarrier transmission (HMT) systems based on a maximizing signal-to-interference-plus-noise ratio (Max-SINR) criterion is proposed. Theoretical analyses show that there is a timing offset between the prototype pulses of the proposed Max-SINR receiver and a traditional projection receiver. Meanwhile, the timing offset should be matched to the Channel scattering factor of a doubly Dispersive (DD) Channel. The closed-form timing offset expressions of the prototype pulses for the Max-SINR HMT receiver over the DD Channel with different Channel scattering functions are derived. Simulation results show that the proposed Max-SINR receiver outperforms the traditional projection scheme and obtains an approximation to the theoretical upper bound SINR performance. Consistent with the SINR performance improvement, the bit error rate (BER) performance of the HMT system has been also further improved by using the proposed Max-SINR receiver. Meanwhile, the SINR performance of the proposed Max-SINR receiver is robust to the Channel delay spread estimation errors.

  • on max sinr receiver for hmt system over doubly Dispersive Channel
    arXiv: Information Theory, 2013
    Co-Authors: Dongmei Zhang
    Abstract:

    In this paper, a novel receiver for Hexagonal Multicarrier Transmission (HMT) system based on the maximizing Signal-to-Interference-plus-Noise Ratio (Max-SINR) criterion is proposed. Theoretical analyses show that there is a timing offset between the prototype pulses of the proposed Max-SINR receiver and the traditional projection receiver. Meanwhile, the timing offset should be matched to the Channel scattering factor of the doubly Dispersive (DD) Channel. The closed form timing offset expressions of the prototype pulse for Max-SINR HMT receiver over DD Channel with different Channel scattering functions are derived. Simulation results show that the proposed Max-SINR receiver outperforms traditional projection scheme and obtains an approximation to the theoretical upper bound SINR performance. Consistent with the SINR performance improvement, the bit error rate (BER) performance of HMT system has also been further improved by using the proposed Max-SINR receiver. Meanwhile, the SINR performance of the proposed Max-SINR receiver is robust to the Channel delay spread estimation errors.

  • On Max-SINR Receiver for Hexagonal Multicarrier Transmission Over Doubly Dispersive Channel
    2012 IEEE Global Communications Conference (GLOBECOM), 2012
    Co-Authors: Xiaochen Xia, Dongmei Zhang
    Abstract:

    In this paper, a novel receiver for Hexagonal Multicarrier Transmission (HMT) system based on the maximizing Signal-to-Interference-plus-Noise Ratio (Max-SINR) criterion is proposed. Theoretical analysis shows that the prototype pulse of the proposed Max-SINR receiver should adapt to the root mean square (RMS) delay spread of the doubly Dispersive (DD) Channel with exponential power delay profile and U-shape Doppler spectrum. Simulation results show that the proposed Max-SINR receiver outperforms traditional projection scheme and obtains an approximation to the theoretical upper bound SINR performance within the full range of Channel spread factor. Meanwhile, the SINR performance of the proposed prototype pulse is robust to the estimation error between the estimated value and the real value of time delay spread.

  • SINR Analysis of Hexagonal Multicarrier Transmission Systems in the Presence of Insufficient Synchronization for Doubly Dispersive Channel
    Frequenz, 2011
    Co-Authors: Dongmei Zhang
    Abstract:

    This paper analyzes the effect of the insuffi- cient synchronization (carrier frequency offset, timing off- set) on hexagonal multicarrier transmission (HMT) systems for doubly Dispersive Channel. Exact SINR and demodu- lated symbol expressions for HMT systems in the presence of insufficient synchronization transmission conditions over doubly Dispersive Channel with exponential delay power profile and U-shape Doppler power spectrum and uniform delay power profile and uniform Doppler power spectrum are derived, respectively. Theoretical analysis shows that similar degradations on symbol amplitude and phase caused by insufficient synchronization are incurred as in traditional cyclic-prefix orthogonal frequency division multiplexing (CP-OFDM) transmission. HMT systems outperform tradi- tional OFDM systems with respect to signal to interference- plus-noise-ratio (SINR) against inter-symbol interference (ISI) and inter-carrier interference (ICI) caused by insuffi- cient synchronization and doubly Dispersive(DD) Channel. The BER performance of the HMT systems using Monte Carlo simulation match with the conclusion given by the proposed exact SINR expression.

Sibasish Das - One of the best experts on this subject based on the ideXlab platform.

  • max sinr isi ici shaping multicarrier communication over the doubly Dispersive Channel
    IEEE Transactions on Signal Processing, 2007
    Co-Authors: Sibasish Das, Philip Schniter
    Abstract:

    For communication over doubly Dispersive Channels, we consider the design of multicarrier modulation (MCM) schemes based on time-frequency shifts of prototype pulses. We consider the case where the receiver knows the Channel state and the transmitter knows the Channel statistics (e.g., delay spread and Doppler spread) but not the Channel state. Previous work has examined MCM pulses designed for suppression of inter-symbol/inter-carrier interference (ISI/ICI) subject to orthogonal or biorthogonal constraints. In doubly Dispersive Channels, however, complete suppression of ISI/ICI is impossible, and the ISI/ICI pattern generated by these (bi)orthogonal schemes can be difficult to equalize, especially when operating at high bandwidth efficiency. We propose a different approach to MCM pulse design, whereby a limited expanse of ISI/ICI is tolerated in modulation/demodulation and treated near-optimally by a downstream equalizer. Specifically, we propose MCM pulse designs that maximize a signal-to-interference-plus-noise ratio (SINR) which suppresses ISI/ICI outside a target pattern. In addition, we propose two low-complexity turbo equalizers, based on minimum mean-squared error and maximum likelihood criteria, respectively, that leverage the structure of the target ISI/ICI pattern. The resulting system exhibits an excellent combination of low complexity, low bit-error rate, and high spectral efficiency.

  • Max-SINR ISI/ICI-shaping multicarrier communication over the doubly Dispersive Channel
    IEEE Transactions on Signal Processing, 2007
    Co-Authors: Sibasish Das, Philip Schniter
    Abstract:

    For communication over doubly Dispersive Channels, we consider the design of multicarrier modulation (MCM) schemes based on time-frequency shifts of prototype pulses. We consider the case where the receiver knows the Channel state and the transmitter knows the Channel statistics (e.g., delay spread and Doppler spread) but not the Channel state. Previous work has examined MCM pulses designed for suppression of inter-symbol/inter-carrier interference (ISI/ICI) subject to orthogonal or biorthogonal constraints. In doubly Dispersive Channels, however, complete suppression of ISI/ICI is impossible, and the ISI/ICI pattern generated by these (bi)orthogonal schemes can be difficult to equalize, especially when operating at high bandwidth efficiency. We propose a different approach to MCM pulse design, whereby a limited expanse of ISI/ICI is tolerated in modulation/demodulation and treated near-optimally by a downstream equalizer. Specifically, we propose MCM pulse designs that maximize a signal-to-interference-plus-noise ratio (SINR) which suppresses ISI/ICI outside a target pattern. In addition, we propose two low-complexity turbo equalizers, based on minimum mean-squared error and maximum likelihood criteria, respectively, that leverage the structure of the target ISI/ICI pattern. The resulting system exhibits an excellent combination of low complexity, low bit-error rate, and high spectral efficiency.

  • Communication Over the Doubly Dispersive Channel
    2007
    Co-Authors: Sibasish Das, Philip Schniter
    Abstract:

    For communication over doubly Dispersive Channels, we consider the design of multicarrier modulation (MCM) schemes based on time-frequency shifts of prototype pulses. We consider the case where the receiver knows the Channel state and the trans- mitter knows the Channel statistics (e.g., delay spread and Doppler spread) but not the Channel state. Previous work has examined MCM pulses designed for suppression of inter-symbol/inter-car- rier interference (ISI/ICI) subject to orthogonal or biorthogonal constraints. In doubly Dispersive Channels, however, complete sup- pression of ISI/ICI is impossible, and the ISI/ICI pattern gener- ated by these (bi)orthogonal schemes can be difficult to equalize, especially when operating at high bandwidth efficiency. We pro- pose a different approach to MCM pulse design, whereby a limited expanse of ISI/ICI is tolerated in modulation/demodulation and treated near-optimally by a downstream equalizer. Specifically, we propose MCM pulse designs that maximize a signal-to-interfer- ence-plus-noise ratio (SINR) which suppresses ISI/ICI outside a target pattern. In addition, we propose two low-complexity turbo equalizers, based on minimum mean-squared error and maximum likelihood criteria, respectively, that leverage the structure of the target ISI/ICI pattern. The resulting system exhibits an excellent combination of low complexity, low bit-error rate, and high spec- tral efficiency. Index Terms—Equalization, doubly Dispersive Channel, inter- carrier interference (ICI), inter-symbol interference (ISI), modu- lation, multicarrier, multipath, pulse-shape, time-varying Channel, turbo-equalization, wireless communications.

Yanzhi Sun - One of the best experts on this subject based on the ideXlab platform.

  • Channel estimation for ofdm systems over time varying and sparse Dispersive Channels
    Vehicular Technology Conference, 2012
    Co-Authors: Qilin Guo, Qinjuan Zhang, Xiaofang Hao, Yanzhi Sun
    Abstract:

    Time-varying Channel gains are approximated by basis expansion model (BEM) to make the tremendous unknowns estimation feasible in orthogonal frequency division multiplexing (OFDM) systems. However, sparse Dispersive Channel requires overloaded subcarriers for pilot-aided estimation in the framework of BEM. This paper proposes a Channel estimation scheme over time-varying and sparse Dispersive Channel with circular grouped pilot pattern, which occupies much less subcarriers. In this scheme, the sparse tap delays are detected with the interpolated Channel frequency response and the modified BEM based estimation deals with only the detected taps, eliminating the noise interference from the null taps. The proposed estimator outperforms the existing methods applied to sparse Dispersive Channel with higher spectral efficiency. Our claims are verified by simulation results, which are obtained in COST207 typical urban Channel model.

  • VTC Spring - Channel Estimation for OFDM Systems over Time-Varying and Sparse Dispersive Channels
    2012 IEEE 75th Vehicular Technology Conference (VTC Spring), 2012
    Co-Authors: Qilin Guo, Qinjuan Zhang, Xiaofang Hao, Yanzhi Sun
    Abstract:

    Time-varying Channel gains are approximated by basis expansion model (BEM) to make the tremendous unknowns estimation feasible in orthogonal frequency division multiplexing (OFDM) systems. However, sparse Dispersive Channel requires overloaded subcarriers for pilot-aided estimation in the framework of BEM. This paper proposes a Channel estimation scheme over time-varying and sparse Dispersive Channel with circular grouped pilot pattern, which occupies much less subcarriers. In this scheme, the sparse tap delays are detected with the interpolated Channel frequency response and the modified BEM based estimation deals with only the detected taps, eliminating the noise interference from the null taps. The proposed estimator outperforms the existing methods applied to sparse Dispersive Channel with higher spectral efficiency. Our claims are verified by simulation results, which are obtained in COST207 typical urban Channel model.

Qilin Guo - One of the best experts on this subject based on the ideXlab platform.

  • Channel estimation for ofdm systems over time varying and sparse Dispersive Channels
    Vehicular Technology Conference, 2012
    Co-Authors: Qilin Guo, Qinjuan Zhang, Xiaofang Hao, Yanzhi Sun
    Abstract:

    Time-varying Channel gains are approximated by basis expansion model (BEM) to make the tremendous unknowns estimation feasible in orthogonal frequency division multiplexing (OFDM) systems. However, sparse Dispersive Channel requires overloaded subcarriers for pilot-aided estimation in the framework of BEM. This paper proposes a Channel estimation scheme over time-varying and sparse Dispersive Channel with circular grouped pilot pattern, which occupies much less subcarriers. In this scheme, the sparse tap delays are detected with the interpolated Channel frequency response and the modified BEM based estimation deals with only the detected taps, eliminating the noise interference from the null taps. The proposed estimator outperforms the existing methods applied to sparse Dispersive Channel with higher spectral efficiency. Our claims are verified by simulation results, which are obtained in COST207 typical urban Channel model.

  • VTC Spring - Channel Estimation for OFDM Systems over Time-Varying and Sparse Dispersive Channels
    2012 IEEE 75th Vehicular Technology Conference (VTC Spring), 2012
    Co-Authors: Qilin Guo, Qinjuan Zhang, Xiaofang Hao, Yanzhi Sun
    Abstract:

    Time-varying Channel gains are approximated by basis expansion model (BEM) to make the tremendous unknowns estimation feasible in orthogonal frequency division multiplexing (OFDM) systems. However, sparse Dispersive Channel requires overloaded subcarriers for pilot-aided estimation in the framework of BEM. This paper proposes a Channel estimation scheme over time-varying and sparse Dispersive Channel with circular grouped pilot pattern, which occupies much less subcarriers. In this scheme, the sparse tap delays are detected with the interpolated Channel frequency response and the modified BEM based estimation deals with only the detected taps, eliminating the noise interference from the null taps. The proposed estimator outperforms the existing methods applied to sparse Dispersive Channel with higher spectral efficiency. Our claims are verified by simulation results, which are obtained in COST207 typical urban Channel model.