References of "Spano, Danilo 50003615"
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See detailSpatial PAPR Reduction in Symbol-level Precoding for the Multi-beam Satellite Downlink
Spano, Danilo UL; Alodeh, Maha UL; Chatzinotas, Symeon UL et al

in IEEE SPAWC 2017 (2017, July)

In this work, a novel symbol-level precoding scheme is proposed, for managing the multi-user interference in the forward downlink channel of a multi-beam satellite system. Besides exploiting the ... [more ▼]

In this work, a novel symbol-level precoding scheme is proposed, for managing the multi-user interference in the forward downlink channel of a multi-beam satellite system. Besides exploiting the constructive interference effect, the proposed scheme aims at improving the robustness of the transmitted signals to the non-linear distortions of practical satellite systems. This is done by reducing the imbalances between the instantaneous power transmitted by the multiple antennas, which are detrimental in non-linear systems. More specifically, this work proposes a symbol-level precoding scheme performing the minimization of the spatial peak-to-average power ratio, under Quality-of-Service constraints. An iterative algorithm is proposed to solve the related optimization problem. Numerical results are presented to assess the performance of the proposed scheme, which outperforms the state of the art symbol-level precoding techniques in terms of spatial peak-to-average power ratio across the transmitting antennas. [less ▲]

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See detailFaster-than-Nyquist Spatiotemporal Symbol-level Precoding in the Downlink of Multiuser MISO Channels
Alodeh, Maha UL; Spano, Danilo UL; Chatzinotas, Symeon UL et al

in The 42nd IEEE International Conference on Acoustics, Speech and Signal Processing (2017, March)

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See detailPer-antenna Power Minimization in Symbol-Level Precoding
Spano, Danilo UL; Alodeh, Maha UL; Chatzinotas, Symeon UL et al

in IEEE GLOBECOM 2016 (2016, December)

This paper investigates the problem of the interference among multiple simultaneous transmissions in the downlink channel of a multi-antenna wireless system. A symbol-level precoding scheme is considered ... [more ▼]

This paper investigates the problem of the interference among multiple simultaneous transmissions in the downlink channel of a multi-antenna wireless system. A symbol-level precoding scheme is considered, where the data information is used, along with the channel state information, in order to exploit the multi-user interference and transform it into useful power at the receiver side. In this framework, it is important to consider the power limitations individually for each transmitting antenna, since a common practice in multi-antenna systems is the use of separate per-antenna amplifiers. Thus, herein the problem of per-antenna power minimization in symbol-level precoding is formulated and solved, under Quality-of-Service constraints. In the proposed approach, the precoding design is optimized in order to control the instantaneous power transmitted by the antennas, and more specifically to limit the power peaks, while guaranteeing some specific target signal-to-noise ratios at the receivers. Numerical results are presented to show the effectiveness of the proposed scheme, which outperforms the existing state of the art techniques in terms of reduction of the power peaks and of the peak-to-average power ratio across the transmitting antennas. [less ▲]

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See detailPeak Power Minimization in Symbol-level Precoding for Cognitive MISO Downlink Channels
Alodeh, Maha UL; Spano, Danilo UL; Chatzinotas, Symeon UL et al

in IEEE Digital Signal Processing Conference (2016, October 16)

This paper proposes a new symbol-level precoding scheme at the cognitive transmitter that jointly utilizes the data and channel information to reduce the effect of nonlinear amplifiers, by reducing the ... [more ▼]

This paper proposes a new symbol-level precoding scheme at the cognitive transmitter that jointly utilizes the data and channel information to reduce the effect of nonlinear amplifiers, by reducing the maximum antenna power under quality of service constraint at the cognitive receivers. In practice, each transmit antenna has a separate amplifier with individual characteristics. In the proposed approach, the precoding design is optimized in order to control the instantaneous power transmitted by the antennas, and more specifically to limit the power peaks, while guaranteeing some specific target signal-to-noise ratios at the receivers and respecting the interference temperature constraint imposed by the primary system. Numerical results show the effectiveness of the proposed scheme, which outperforms the existing state of the art techniques in terms of reduction of the power peaks. [less ▲]

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See detailSymbol-Level Precoding with Per-antenna Power Constraints for the Multi-beam Satellite Downlink
Spano, Danilo UL; Chatzinotas, Symeon UL; Krause, Jens et al

in 8th Advanced Satellite Multimedia Systems Conference (ASMS) (2016, September)

This paper tackles the problem of multi-user interference in the forward downlink channel of a multi-beam satellite system. A symbol-level precoding scheme is considered, where the data information is ... [more ▼]

This paper tackles the problem of multi-user interference in the forward downlink channel of a multi-beam satellite system. A symbol-level precoding scheme is considered, where the data information is used, along with the channel state information, in order to exploit the multi-user interference and transform it into useful power at the receiver side. In this framework, the max-min fair problem for constructive interference is formulated and solved, under per-antenna power constraints. The consideration of the power limitations individually for each transmitting RF chain is the novel aspect, and it is relevant in particular for systems suffering non-linear effects of the channel. This is the case of satellite systems, where the non-linear amplifiers should be properly driven in order to reduce the detrimental saturation effect. The proposed precoding design optimizes the system performance at the receiver side in terms of signal-to-noise ratio, whilst guaranteeing the system fairness and allowing a control over the power transmitted by each antenna, in particular reducing the power peaks. Numerical results are presented to validate the proposed scheme, and to show its effectiveness in terms of distribution of the transmitted power and peak-to-average power ratio. [less ▲]

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See detailMultibeam joint processing satellites: cooperative relays, high above.
Christopoulos, Dimitrios; Andrenacci, Stefano UL; Spano, Danilo UL et al

in Advanced Relay Technologies in Next Generation Wireless Communication, Telecommunications (2016)

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See detailOptimized Link Adaptation for DVB-S2X Precoded Waveforms based on SNIR Estimation
Andrenacci, Stefano UL; Spano, Danilo UL; Christopoulos, Dimitrios et al

in Asilomar Conference on Signals, Systems, and Computers 2016 (2016)

The present work deals with optimized strategies to address the issue of link adaptation (Adaptive Coding and Modulation - ACM) in a multi-user multi-beam satellite system employing precoding at the ... [more ▼]

The present work deals with optimized strategies to address the issue of link adaptation (Adaptive Coding and Modulation - ACM) in a multi-user multi-beam satellite system employing precoding at the gateway side. Accordingly, the focus is on the forward link of a multi-beam satellite system employing a full frequency reuse configuration. In such an interference limited setting, the Super-Framing structure of DVB-S2X air interface (format specification 2 and 3) enables the use of precoding techniques. The aim herein is to investigate the Signal-to-Noise-plus- Interference (SNIR) estimation error given by the User Terminals (UTs) through the so-called P2 pilots is taken into account to optimize the ACM margins. [less ▲]

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See detailTotal degradation analysis of precoded signals onto non-linear satellite channels
Spano, Danilo UL; Christopoulos, Dimitrios UL; Andrenacci, Stefano UL et al

in 21st Ka Conference (2015, October)

Linear precoding exploits the spatial degrees of freedom offered by multi-antenna transmitters to manage interferences between multiple co-channel users. The adoption of precoding in practical systems ... [more ▼]

Linear precoding exploits the spatial degrees of freedom offered by multi-antenna transmitters to manage interferences between multiple co-channel users. The adoption of precoding in practical systems, however, entails a series of practical barriers. Amongst several issues, the focus herein is on the non-linear dependence of the input versus the output power of the efficient and reliable amplifiers that drive each transmit antenna, which limits the system performance. As a first step, the present work studies the impact of linear precoding on the peak-to-average power ratio (PAPR) of precoded waveforms in multibeam satellite systems using a finite alphabet. In this context, a sensitivity analysis of the PAPR at the input of each amplifier with respect to intrinsic system level parameters, such as the number of transmit feeds, is performed. Next, the performance of the whole non-linear satellite chain is analyzed with respect to the symbol-error-rate (SER) and the total degradation (TD) of the channel. Furthermore, two low-complexity solutions are considered for counteracting the effects of the non-linearities of the satellite channel on the precoded waveforms, namely an automatic gain control (AGC) operation and a non-linear equalization performed at the receiver side. [less ▲]

Detailed reference viewed: 190 (38 UL)