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Author

Antonio Assalini

Bio: Antonio Assalini is an academic researcher from University of Padua. The author has contributed to research in topics: Communication channel & Orthogonal frequency-division multiplexing. The author has an hindex of 12, co-authored 22 publications receiving 407 citations.

Papers
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Journal ArticleDOI
TL;DR: Two new Nyquist (intersymbol interference free) pulses are proposed that exhibit better error probability performance in the presence of sampling errors than the popular raised-cosine and a recently proposed pulse by Beaulieu, Tan, and Damen.
Abstract: In this letter, we propose two new Nyquist (intersymbol interference free) pulses that exhibit better error probability performance in the presence of sampling errors than the popular raised-cosine and a recently proposed pulse by Beaulieu, Tan, and Damen. The new pulses are also robust to the root and truncation operations.

125 citations

Journal ArticleDOI
TL;DR: In this paper, the authors theoretically study the quantum receivers for discriminating ternary and quaternary phase-shift-keying coherent states in terms of average error rate and mutual information, and analytically examine the asymptotic limit of the proposed receiver with respect to the number of feedforward steps.
Abstract: The quantum receiver is an important tool for overcoming the standard quantum limit (SQL) of discrimination errors in optical communication. We theoretically study the quantum receivers for discriminating ternary and quaternary phase-shift-keying coherent states in terms of average error rate and mutual information. Our receiver consists of on-off--type photon detectors and displacement operations without electrical feedforward operations. We show that for the ternary signals, the receiver shows a reasonable gain from the SQL even without feedforward. This scheme is realizable with the currently available technology. For the quaternary signals feedforward operation is crucial to overcome the SQL with imperfect devices. We also analytically examine the asymptotic limit of the performance of the proposed receiver with respect to the number of feedforward steps.

57 citations

Journal ArticleDOI
TL;DR: A suboptimal detection scheme derived from the Dolinar's architecture is proposed and investigated, which is shown to slightly outperform some other near-optimal schemes available in the literature.
Abstract: We consider the problem of discriminating between two quantum coherent states by interpreting a single state as being a collection of several successive copies of weaker coherent states. By means of recent results on multiple-copy state discrimination, it is possible to give a reinterpretation of the Dolinar receiver and carry out a quite-straightforward analysis of its behavior. We also propose and investigate a suboptimal detection scheme derived from the Dolinar's architecture, which is shown to slightly outperform some other near-optimal schemes available in the literature.

44 citations

Journal ArticleDOI
TL;DR: In this paper, the authors numerically evaluate the deep-space communication performance in a broadband lossy channel of coherent PPM with an on/off receiver, single-symbol square root detection, and Holevo information.
Abstract: We numerically evaluate the deep-space communication performance in a broadband lossy channel of coherent pulse position modulation (PPM) with an on/off receiver, single-symbol square root detection, and Holevo information. We also consider quadrature amplitude modulation (QAM) signals and phase-shift keying signals with dyne-type detections. We show the quantitative gap between these detection strategies in terms of the capacity, particularly in the quantum-limited region where the quantum noise seriously limits the transmission rate. In particular, we find that for an extremely weak signal input power, use of a multilevel PPM system is a good strategy, whereas for an extremely strong signal, use of a multilevel QAM system is recommended.

36 citations

Proceedings ArticleDOI
26 Apr 2009
TL;DR: This paper proposes and study upper and lower bounds on the MIMO channel capacity giving emphasis to the impact of the resulting channel estimation error, through its covariance matrix.
Abstract: This paper deals with the impact of channel es- timation errors on the capacity of correlated fading MIMO channels. In literature the effect of channel uncertainty at the receiver is often investigated with the assumption that channel estimation errors are identically distributed and independent of both SNR and channel correlation values. In this paper we extend the analysis by considering correlation among the channel estimation errors as typically happen when the MIMO channel to be estimated is spatially correlated. We propose and study upper and lower bounds on the MIMO channel capacity giving emphasis to the impact of the resulting channel estimation error, through its covariance matrix. The role played by the effective SNR and spatial correlation is studied by detailing the results to MIMO systems employing linear MMSE channel estimators. I. INTRODUCTION

24 citations


Cited by
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Patent
29 Oct 2003
TL;DR: In this article, the transmit power for the pilot was scaled higher to attain the same total pilot energy even though S instead of M subbands are used for pilot transmission by each terminal, and a channel estimate was derived for each terminal based on the pilot received on the assigned subbands.
Abstract: Techniques to more efficiently transmit pilot and signaling on the uplink in an OFDM system. With subband multiplexing, M usable subbands in the system are partitioned into Q disjoint groups of subbands. Each subband group may be assigned to a different terminal for uplink pilot transmission. Multiple terminals may transmit simultaneously on their assigned subbands. The transmit power for the pilot may be scaled higher to attain the same total pilot energy even though S instead of M subbands are used for pilot transmission by each terminal. Pilot transmissions from the terminals are received, and a channel estimate is derived for each terminal based on the pilot received on the assigned subbands. The channel estimate comprises a response for additional subbands not included in the assigned group. Subband multiplexing may also be used for uplink signaling transmission.

215 citations

Patent
07 May 2004
TL;DR: In this paper, the authors provide techniques to support fast frequency hopping with a code division multiplexed (CDM) pilot in a multi-carrier communication system (e.g., an OFDMA system).
Abstract: Techniques are provided to support fast frequency hopping with a code division multiplexed (CDM) pilot in a multi-carrier communication system (e.g., an OFDMA system). Each transmitter (e.g., each terminal) in the system transmits a wideband pilot on all subbands to allow a receiver (e.g., a base station) to estimate the entire channel response at the same time. The wideband pilot for each transmitter may be generated using direct sequence spread spectrum processing and based on a pseudo-random number (PN) code assigned to that transmitter. This allows the receiver to individually identify and recover multiple wideband pilots transmitted concurrently by multiple transmitters. For a time division multiplexed (TDM)/CDM pilot transmission scheme, each transmitter transmits the wideband pilot in bursts. For a continuous CDM pilot transmission scheme, each transmitter continuously transmits the wideband pilot, albeit at a low transmit power level. Any frequency hopping rate may be supported without impacting pilot overhead.

167 citations

Journal ArticleDOI
TL;DR: A quantum receiver based on a novel adaptive measurement scheme and a high-bandwidth, high-detection-efficiency system for single-photon counting and an unconditionally discriminates between four nonorthogonal coherent states is presented.
Abstract: Researchers present a quantum receiver based on a novel adaptive measurement scheme and a high-bandwidth, high-detection-efficiency system for single-photon counting. The receiver unconditionally discriminates between four nonorthogonal coherent states with error probabilities 6 dB below the standard quantum limit for a wide range of input powers.

160 citations

Patent
Edward Harrison Teague1
28 Jan 2005
TL;DR: In this article, a method and apparatus for providing an acknowledgement (ACK) message combined with one or more communication message of a data packet that is transmitted using a single channel is provided.
Abstract: A method and apparatus are provided for providing an acknowledgement (ACK) message combined with one or more communication message of a data packet that is transmitted using a single channel. The method comprising acts of associating the ACK with a channel ID of a recipient; building the ACK information data pattern, wherein the length of the ACK message is based on number of ACK messages to be transmitted; and combining the ACK information data pattern with one or more communication message by applying an encoding scheme over the combined message.

128 citations