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Rudolf Mathar - One of the best experts on this subject based on the ideXlab platform.

  • On the Achievable Rate of Stationary Rayleigh Flat-Fading Channels With Gaussian Inputs
    IEEE Transactions on Information Theory, 2013
    Co-Authors: Meik Dorpinghaus, Heinrich Meyr, Rudolf Mathar
    Abstract:

    In this work, a discrete-time stationary Rayleigh flat-fading channel with unknown channel state information at transmitter and receiver side is studied. The law of the channel is presumed to be known to the receiver. For independent identically distributed (i.i.d.) zero-mean proper Gaussian Input distributions, the achievable rate is investigated. The main contribution of this paper is the derivation of two new upper bounds on the achievable rate with Gaussian Input symbols. One of these bounds is based on the one-step channel prediction error variance but is not restricted to peak power constrained Input symbols like known bounds. Moreover, it is shown that Gaussian Inputs yield the same pre-log as the peak power constrained capacity. The derived bounds are compared with a known lower bound on the capacity given by Deng and Haimovich and with bounds on the peak power constrained capacity given by Sethuraman et al.. Finally, the achievable rate with i.i.d. Gaussian Input symbols is compared to the achievable rate using a coherent detection in combination with a solely pilot-based channel estimation.

Meik Dorpinghaus - One of the best experts on this subject based on the ideXlab platform.

  • On the Achievable Rate of Stationary Rayleigh Flat-Fading Channels With Gaussian Inputs
    IEEE Transactions on Information Theory, 2013
    Co-Authors: Meik Dorpinghaus, Heinrich Meyr, Rudolf Mathar
    Abstract:

    In this work, a discrete-time stationary Rayleigh flat-fading channel with unknown channel state information at transmitter and receiver side is studied. The law of the channel is presumed to be known to the receiver. For independent identically distributed (i.i.d.) zero-mean proper Gaussian Input distributions, the achievable rate is investigated. The main contribution of this paper is the derivation of two new upper bounds on the achievable rate with Gaussian Input symbols. One of these bounds is based on the one-step channel prediction error variance but is not restricted to peak power constrained Input symbols like known bounds. Moreover, it is shown that Gaussian Inputs yield the same pre-log as the peak power constrained capacity. The derived bounds are compared with a known lower bound on the capacity given by Deng and Haimovich and with bounds on the peak power constrained capacity given by Sethuraman et al.. Finally, the achievable rate with i.i.d. Gaussian Input symbols is compared to the achievable rate using a coherent detection in combination with a solely pilot-based channel estimation.

  • On the Achievable Rate of Stationary Rayleigh Flat-Fading Channels with Gaussian Inputs
    arXiv: Information Theory, 2011
    Co-Authors: Meik Dorpinghaus, Heinrich Meyr
    Abstract:

    In this work, we consider a discrete-time stationary Rayleigh flat-fading channel with unknown channel state information at transmitter and receiver. The law of the channel is presumed to be known to the receiver. In addition, we assume the power spectral density (PSD) of the fading process to be compactly supported. For i.i.d. zero-mean proper Gaussian Input distributions, we investigate the achievable rate. One of the main contributions is the derivation of two new upper bounds on the achievable rate with zero-mean proper Gaussian Input symbols. The first one holds only for the special case of a rectangular PSD and depends on the SNR and the spread of the PSD. Together with a lower bound on the achievable rate, which is achievable with i.i.d. zero-mean proper Gaussian Input symbols, we have found a set of bounds which is tight in the sense that their difference is bounded. Furthermore, we show that the high SNR slope is characterized by a pre-log of 1-2f_d, where f_d is the normalized maximum Doppler frequency. This pre-log is equal to the high SNR pre-log of the peak power constrained capacity. Furthermore, we derive an alternative upper bound on the achievable rate with i.i.d. Input symbols which is based on the one-step channel prediction error variance. The novelty lies in the fact that this bound is not restricted to peak power constrained Input symbols like known bounds, e.g. in [1]. Therefore, the derived upper bound can also be used to evaluate the achievable rate with i.i.d. proper Gaussian Input symbols. We compare the derived bounds on the achievable rate with i.i.d. zero-mean proper Gaussian Input symbols with bounds on the peak power constrained capacity given in [1-3]. Finally, we compare the achievable rate with i.i.d. zero-mean proper Gaussian Input symbols with the achievable rate using synchronized detection in combination with a solely pilot based channel estimation.

  • On the achievable rate of stationary Rayleigh flat-fading channels with Gaussian Input distribution
    2008 International Symposium on Information Theory and Its Applications, 2008
    Co-Authors: Meik Dorpinghaus, M. Senst, Gerd Ascheid, Heinrich Meyr
    Abstract:

    For a Gaussian Input distribution, we investigate the achievable rate of a stationary Rayleigh flat-fading channel under the assumption of unknown channel state information at transmitter and receiver side. The law of the channel is presumed to be known to the receiver. In addition, we assume the power spectral density of the fading process to be compactly supported. The contribution of the present paper is the derivation of an upper bound on the achievable rate for the special case of a rectangular power spectral density depending on the SNR and the spread of the power spectral density. For comparison, we also give a lower bound on the achievable rate which is already known from and holds for an arbitrary power spectral density.

Heinrich Meyr - One of the best experts on this subject based on the ideXlab platform.

  • On the Achievable Rate of Stationary Rayleigh Flat-Fading Channels With Gaussian Inputs
    IEEE Transactions on Information Theory, 2013
    Co-Authors: Meik Dorpinghaus, Heinrich Meyr, Rudolf Mathar
    Abstract:

    In this work, a discrete-time stationary Rayleigh flat-fading channel with unknown channel state information at transmitter and receiver side is studied. The law of the channel is presumed to be known to the receiver. For independent identically distributed (i.i.d.) zero-mean proper Gaussian Input distributions, the achievable rate is investigated. The main contribution of this paper is the derivation of two new upper bounds on the achievable rate with Gaussian Input symbols. One of these bounds is based on the one-step channel prediction error variance but is not restricted to peak power constrained Input symbols like known bounds. Moreover, it is shown that Gaussian Inputs yield the same pre-log as the peak power constrained capacity. The derived bounds are compared with a known lower bound on the capacity given by Deng and Haimovich and with bounds on the peak power constrained capacity given by Sethuraman et al.. Finally, the achievable rate with i.i.d. Gaussian Input symbols is compared to the achievable rate using a coherent detection in combination with a solely pilot-based channel estimation.

  • On the Achievable Rate of Stationary Rayleigh Flat-Fading Channels with Gaussian Inputs
    arXiv: Information Theory, 2011
    Co-Authors: Meik Dorpinghaus, Heinrich Meyr
    Abstract:

    In this work, we consider a discrete-time stationary Rayleigh flat-fading channel with unknown channel state information at transmitter and receiver. The law of the channel is presumed to be known to the receiver. In addition, we assume the power spectral density (PSD) of the fading process to be compactly supported. For i.i.d. zero-mean proper Gaussian Input distributions, we investigate the achievable rate. One of the main contributions is the derivation of two new upper bounds on the achievable rate with zero-mean proper Gaussian Input symbols. The first one holds only for the special case of a rectangular PSD and depends on the SNR and the spread of the PSD. Together with a lower bound on the achievable rate, which is achievable with i.i.d. zero-mean proper Gaussian Input symbols, we have found a set of bounds which is tight in the sense that their difference is bounded. Furthermore, we show that the high SNR slope is characterized by a pre-log of 1-2f_d, where f_d is the normalized maximum Doppler frequency. This pre-log is equal to the high SNR pre-log of the peak power constrained capacity. Furthermore, we derive an alternative upper bound on the achievable rate with i.i.d. Input symbols which is based on the one-step channel prediction error variance. The novelty lies in the fact that this bound is not restricted to peak power constrained Input symbols like known bounds, e.g. in [1]. Therefore, the derived upper bound can also be used to evaluate the achievable rate with i.i.d. proper Gaussian Input symbols. We compare the derived bounds on the achievable rate with i.i.d. zero-mean proper Gaussian Input symbols with bounds on the peak power constrained capacity given in [1-3]. Finally, we compare the achievable rate with i.i.d. zero-mean proper Gaussian Input symbols with the achievable rate using synchronized detection in combination with a solely pilot based channel estimation.

  • On the achievable rate of stationary Rayleigh flat-fading channels with Gaussian Input distribution
    2008 International Symposium on Information Theory and Its Applications, 2008
    Co-Authors: Meik Dorpinghaus, M. Senst, Gerd Ascheid, Heinrich Meyr
    Abstract:

    For a Gaussian Input distribution, we investigate the achievable rate of a stationary Rayleigh flat-fading channel under the assumption of unknown channel state information at transmitter and receiver side. The law of the channel is presumed to be known to the receiver. In addition, we assume the power spectral density of the fading process to be compactly supported. The contribution of the present paper is the derivation of an upper bound on the achievable rate for the special case of a rectangular power spectral density depending on the SNR and the spread of the power spectral density. For comparison, we also give a lower bound on the achievable rate which is already known from and holds for an arbitrary power spectral density.

Lajos Hanzo - One of the best experts on this subject based on the ideXlab platform.

  • A Finite Input Alphabet Perspective on the Rate-Energy Tradeoff in SWIPT Over Parallel Gaussian Channels
    IEEE Journal on Selected Areas in Communications, 2019
    Co-Authors: Rakshith Rajashekar, Marco Di Renzo, Lie-liang Yang, K.v.s. Hari, Lajos Hanzo
    Abstract:

    Simultaneous wireless information and power transfer (SWIPT) has gained significant popularity in the recent past owing to its applications in a wide range of use cases. Although SWIPT has been fairly well investigated in the literature, the existing work has mainly focused on attaining the optimal rate energy (RE) tradeoff assuming Gaussian Input alphabet. However, practical systems operate with finite Input alphabets such as quadratic-amplitude modulation (QAM)/phase-shift keying. We characterize the attainable RE tradeoff in SWIPT systems employing finite Input alphabet for transmission over parallel Gaussian channels of say orthogonal frequency-division multiplexing subcarriers or multiple-Input multiple-output streams. Some of the key results in the literature that assume Gaussian Input alphabet are shown to be special cases of our results. Furthermore, we provide insights into our results with the aid of graphical illustrations, which throw light on the optimal power allocation policy for various energy-harvesting constraints. Furthermore, we consider practically relevant time-sharing and power-splitting schemes operating with finite Input alphabet and characterize their RE tradeoff. Their optimal solutions in the asymptotic regime are obtained, which serve as low-complexity solutions suitable for practical implementation. Our simulation studies have demonstrated that the Gaussian Input assumption significantly over-estimates the attainable RE tradeoff, especially when the signal set employed is small. Furthermore, it is observed through numerical simulations that the proposed optimal power allocation performs significantly better than the power allocation based on the Gaussian Input assumption. Specifically, as much as 30% rate improvement is observed when employing the classic 4-QAM signal set.

  • A Finite Input Alphabet Perspective on the Rate-Energy Tradeoff in SWIPT Over Parallel Gaussian Channels
    IEEE Journal on Selected Areas in Communications, 2019
    Co-Authors: Rakshith Rajashekar, Marco Di Renzo, Lie-liang Yang, K.v.s. Hari, Lajos Hanzo
    Abstract:

    Simultaneous wireless information and power transfer (SWIPT) has gained significant popularity in the recent past owing to its applications in a wide range of use-cases. Although SWIPT has been fairly well investigated in the literature, the existing work has mainly focused on attaining the optimal rate energy (RE) trade-off assuming Gaussian Input alphabet. However , practical systems operate with finite Input alphabets such as QAM/PSK. We characterise the attainable RE trade-off in SWIPT systems employing finite Input alphabet for transmission over parallel Gaussian channels of say orthogonal frequency division multiplexing subcarriers or multiple-Input multiple-output streams. Some of the key results in the literature that assume Gaussian Input alphabet are shown to be special cases of our results. Furthermore, we provide insights into our results with the aid of graphical illustrations, which throw light on the optimal power allocation policy for various energy harvesting constraints. Furthermore, we consider practically relevant time sharing and power splitting schemes operating with finite Input alphabet and characterise their RE trade-off. Their optimal solutions in the asymptotic regime are obtained, which serve as low-complexity solutions suitable for practical implementation. Our simulation studies have demonstrated that the Gaussian Input assumption significantly overestimates the attainable RE trade-off, especially when the signal set employed is small. Furthermore, it is observed through numerical simulations that the proposed optimal power allocation performs significantly better than the power allocation based on the Gaussian Input assumption. Specifically, as much as 30% rate improvement is observed when employing the classic 4-QAM signal set.

Amos Lapidoth - One of the best experts on this subject based on the ideXlab platform.

  • How Good is an Isotropic Gaussian Input on a MIMO Ricean Channel?
    2014
    Co-Authors: Daniel Hösli, Amos Lapidoth
    Abstract:

    Abstract — For a MIMO Ricean fading channel with perfect side information at the receiver we derive an analytic upper bound on the difference between capacity and the mutual information that is induced by an isotropic Gaussian Input. We show that if the number of receiver antennas is at least equal to the number of transmitter antennas, then, as the signal-tonoise ratio tends to infinity, such an Input is asymptotically optimal. But otherwise such an isotropic Input might be suboptimal. We also propose an iterative algorithm to calculate the optimal power allocation. I

  • On the log determinant of noncentral Wishart matrices
    IEEE International Symposium on Information Theory 2003. Proceedings., 2003
    Co-Authors: Young-han Kim, Amos Lapidoth
    Abstract:

    In this paper, we show that the expected log determinant of a complex noncentral Wishart matrix is an increasing function of the noncentrality parameter. This demonstrates that the mutual information corresponding to an isotropically distributed Gaussian Input to a multiantenna Ricean fading channel is nondecreasing in the line-of-sight component.

  • ISIT - How good is an isotropic Gaussian Input on a MIMO Ricean channel
    International Symposium onInformation Theory 2004. ISIT 2004. Proceedings., 1
    Co-Authors: Daniel Hösli, Amos Lapidoth
    Abstract:

    For a MIMO Ricean fading channel with perfect side information at the receiver we derive an analytic upper bound on the difference between capacity and the mutual information that is induced by an isotropic Gaussian Input. We show that if the number of receiver antennas is at least equal to the number of transmitter antennas, then, as the signal-to-noise ratio tends to infinity, such an Input is asymptotically optimal. But otherwise such an isotropic Input might be suboptimal. We also propose an iterative algorithm to calculate the optimal power allocation.