Papers by Alberto Perotti
IEEE Transactions on Vehicular Technology, 2022
Recent advances in Vehicle-to-Everything (V2X) technology and the upcoming sixth-generation (6G) ... more Recent advances in Vehicle-to-Everything (V2X) technology and the upcoming sixth-generation (6G) network will dawn a new era for vehicular services with enhanced communication capabilities. Connected and Autonomous Vehicles (CAVs) are expected to deliver a new transportation experience, increasing the safety and efficiency of road networks. The use of millimeter-wave (mmW) frequencies guarantees a huge amount of bandwidth (>1GHz) and a high data rate (> 10 Gbit/s), which are required for CAVs applications. However, high frequency is impaired by severe path loss, and line of sight (LoS) propagation can be easily blocked by static and dynamic obstacles. Several solutions are being investigated, and the most promising one exploits relays. However, traditional relay schemes react to link failure and leverage instantaneous information, which impedes efficient relay selection in highly mobile and complex networks, such as vehicular scenarios. In this context, we propose a novel proactive relaying strategy that exploits the cooperation between CAVs and environment information to predict the dynamic LoSmap, which describes the links' evolution in time. The proactive relaying schemes exploit the dynamic LoS-map to maximize the network connectivity. A novel framework integrating realistic mobility patterns and geometric channel propagation models is proposed to analyze the performance in different scenarios. Numerical simulations suggest that the proactive relaying schemes mitigate beam blockage and maximize the average probability of connecting CAVs with reliable links.
2022 IEEE 95th Vehicular Technology Conference: (VTC2022-Spring), Jun 1, 2022
arXiv (Cornell University), Jun 19, 2022
Deep neural network (DNN)-based channel code designs have recently gained interest as an alternat... more Deep neural network (DNN)-based channel code designs have recently gained interest as an alternative to conventional coding schemes, particularly for channels where existing codes do not provide satisfactory performance. Coding in the presence of feedback is one such problem, for which promising results have recently been obtained by various DNN-based coding architectures. In this paper, we introduce a novel learning-aided feedback code design, dubbed generalized block attention feedback (GBAF) codes, that achieves order-of-magnitude improvements in block error rate (BLER) compared to existing solutions. Sequence-to-sequence encoding and block-by-block processing of the message bits in GBAF codes not only reduce the communication overhead due to reduced number of interactions between the transmitter and receiver, but also enable flexible coding rates. More importantly, GBAF codes provide a modular structure that can be implemented using different neural network architectures. In this work, we employ the transformer architecture, which outperforms all the prior DNN-based code designs in terms the block error rate in the low signal-to-noise ratio regime when the feedback channel is noiseless. Index Terms Feedback code, deep learning, channel coding, the attention mechanism, ultra-reliable short-packet communications. I. INTRODUCTION Reliable communication in the presence of noise has been a long-standing challenge. Numerous coding and modulation techniques have been invented over many decades to push the
2019 IEEE Global Communications Conference (GLOBECOM), 2019
We introduce a new family of error correction codes based on sparse superposition called Quasi- O... more We introduce a new family of error correction codes based on sparse superposition called Quasi- Orthogonal} Sparse Superposition Codes (QO-SSC). The core of QO-SSC is a special structure of the SSC projection matrix which is obtained by concatenation of orthogonal submatrices. Concrete examples of QO-SCC constructions based on Zadoff- Chu sequences and Kerdock bent sequences are provided. A low-complexity iterative successive interference cancellation algorithm is proposed for QO-SSC decoding. Performance evaluations show that QO-SSC is an efficient solution for short- packet transmission at low signal-to-noise ratios, as it achieves lower block error rate than conventional coded modulation schemes, e.g., QPSK- modulated polar codes. As a further advantage, QO-SSC features a low PAPR when transmitted using OFDM waveforms.
ArXiv, 2021
The Accumulative Iterative Code (AIC) proposed in this work is a new error correcting code for ch... more The Accumulative Iterative Code (AIC) proposed in this work is a new error correcting code for channels with feedback. AIC sends the information message to the receiver in a number of transmissions, where the initial transmission contains the uncoded message and each subsequent transmission informs the receiver about the locations of the errors that corrupted the previous transmission. Error locations are determined based on the forward channel output, which is made available to the transmitter through the feedback channel. AIC achieves arbitrarily low error rates, thereby being suitable for applications demanding extremely high reliability. In the same time, AIC achieves spectral efficiencies very close to the channel capacity in a wide range of signal-to-noise ratios even for transmission of short information messages.
2016 IEEE Global Communications Conference (GLOBECOM), 2016
Superposed transmission on the broadcast channel delivers multiple private messages simultaneousl... more Superposed transmission on the broadcast channel delivers multiple private messages simultaneously to the intended users. Superposed transmission is employed in non-orthogonal multiple access to increase the aggregate throughput and connectivity of wireless cellular systems. Rate-adaptive constellation Expansion Multiple Access (REMA, a.k.a. RA-CEMA) is a non-orthogonal multiple access scheme which exhibits performance similar to the conventional superposed transmission schemes for transmission on the degraded broadcast channel, while requiring less complex signal processing and scheduling algorithms. This paper solves the problem of user scheduling and rate~allocation for REMA. We pose the problem as a weighted sum-rate optimization and develop provably optimal algorithms for user selection and rate allocation with REMA broadcast-channel transmission. System-level evaluations show that our schemes outperform an LTE-A compliant orthogonal multiple access system and exhibit simi...
Performance of coded Frequency-Division Multiplexed Continuous Phase Modulation (FDM-CPM) systems... more Performance of coded Frequency-Division Multiplexed Continuous Phase Modulation (FDM-CPM) systems with Multiple Input Multiple Output (MIMO) transmission is investigated. The system is designed to achieve high spectral efficiency by exploiting the multiplexing gain of MIMO techniques. Moreover, a FDM MultiUser (MU) scheme with tight inter-carrier frequency spacing is used to increase spectral efficiency. It is shown that, using this scheme, significant improvement both in terms of bit error rate and spectral efficiency are obtained when compared to the singleantenna MU scenario. To take advantage of the multiplexing gain of MIMO systems, a Minimum Mean Square Error (MMSE) MIMO detector and a low-complexity iterative algorithm for Inter-Carrier Interference (ICI) cancellation are considered. Numerical simulations have been performed to assess the performance improvement achieved with the proposed frequency-division multiplexed CPM multiuser MIMO system. Keywords-Continuous Phase Modu...
ITU Journal on Future and Evolving Technologies, 2021
A new Deep Neural Network (DNN)-based error correction encoder architecture for channels with fee... more A new Deep Neural Network (DNN)-based error correction encoder architecture for channels with feedback, called Deep Extended Feedback (DEF), is presented in this paper. The encoder in the DEF architecture transmits an information message followed by a sequence of parity symbols which are generated based on the message as well as the observations of the past forward channel outputs sent to the transmitter through a feedback channel. DEF codes generalize Deepcode in several ways: parity symbols are generated based on forward channel output observations over longer time intervals in order to provide better error correction capability; and high-order modulation formats are deployed in the encoder so as to achieve increased spectral efficiency. Performance evaluations show that DEF codes have better performance compared to other DNN-based codes for channels with feedback.
IEEE Communications Magazine, 2021
IEEE Communications Magazine, 2019
Signals and Communication Technology, 2014
ABSTRACT Research on intelligent and reconfigurable wireless systems is in continuous evolution. ... more ABSTRACT Research on intelligent and reconfigurable wireless systems is in continuous evolution. Nevertheless, in order to fix some keystones, more and more researchers are entering the idea of research-oriented test beds. Unfortunately, it is very difficult for a wide number of research groups to start with their own set up, since the potential costs and efforts could not pay back in term of expected research results. Software Defined Radio solutions offer an easy way to communication researchers for the development of customized research test beds. While several hardware products are commercially available, the software is most of the times open source and ready to use for third party users. Even though the software solution developers claim complete easiness in the development of custom applications, in reality there are a number of practical hardware and software issues that research groups need to face, before they are up and running in generating results. With this chapter we would like to provide a tutorial guide, based on direct experience, on how to enter in the world of test bed-based research, providing both insight on the issues encountered in every day development, and practical solutions. Finally, an overview on common research-oriented software products for SDR development, namely GNU Radio, Iris, and ASGARD, will be provided, including how to practically start the software development of simple applications. Finally, best practices and examples of all the software platforms will be provided, giving inspiration to researchers on how to possibly build their own customized systems.
Signals and Communication Technology, 2015
The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.
Signals and Communication Technology, 2014
The aim of this book, the first of two volumes, is to present selected research that has been und... more The aim of this book, the first of two volumes, is to present selected research that has been undertaken under COST Action IC0902 ''Cognitive Radio and Networking for Cooperative Coexistence of Heterogeneous Wireless Networks'' (http://newyork.ing.uniroma1.it/IC0902/). COST (European Cooperation in Science and Technology) is one of the longest-running European frameworks supporting cooperation among scientists and researchers across Europe. Written by leading researchers from both academia and major industrial research laboratories, this book will provide electrical, R&D electronic and communication engineers, as well as researchers, undergraduate, graduate, and postgraduate students with a unique and comprehensive overview of recent advances in cognitive radio (CR) and networks. The book will allow the reader to have access to avant-garde results, in the CR and cooperative heterogeneous coexistence field, in a thorough and detailed way. Topics covered by the book include newly developed techniques on spectrum sensing algorithms for cognitive white-space systems using either single or multiple antennas, and novel blind free-bands detectors exploiting cyclic autocorrelation function sparsity. The reader will also explore learning and optimization techniques and mechanisms based on biomimetic approaches for Self-Organization in Macro-Femtocell Coexistence; these methods are based on the recently developed ''Docition'' concept for cognitive networks. The book further includes extensive discussions regarding issues related to the implementation of the different steps of the cognitive cycle, and, in particular, on reasoning. Application of such concepts to cognitive networks allows defining a potential architecture for their integration into current TCP/IP networks. Indeed, using the cognitive paradigm represents a way toward (i) addressing the multiple timescales of operation of a network and (ii) gaining additional information on the cause-effect relationships between network configuration and performance. A very interesting chapter that describes how cognitive networking can be implemented to support green network operation, proposing a test case and demonstrating its potential in a 3G cellular context, is also included in the book. A complete description of the latest groundbreaking field trials is also available to the reader along with the current and future market requirements and so-called killer applications. Finally, in the last chapter, main conclusions and recommendations regarding the available test beds are reported.
Electronics Letters, 2006
A user-specific interleaver design for interleave-division multipleaccess (IDMA) systems is propo... more A user-specific interleaver design for interleave-division multipleaccess (IDMA) systems is proposed. This method can solve the memory cost problem for chip-level interleavers, and reduce the amount of information exchange between mobile stations and base stations to specify the interleaver used as their identifications.
The results show that if minimum information blocks lengths of some hundreds of bits are consider... more The results show that if minimum information blocks lengths of some hundreds of bits are considered, the use of Turbo codes and SOTC would allow to improve the GNSS data delivery performance in terms of lower thresholds and in terms of higher bit rates to be used either to increase the data throughput or to reduce the Time-To-First-Fix.
In this paper, a concatenated coding scheme consistingof an outer algebraic block code performing... more In this paper, a concatenated coding scheme consistingof an outer algebraic block code performing hard decodingconnected to an inner turbo code through a rectangular interleaveris analyzed. The performance of the concatenated codeis evaluated through a semi-analytical approach, based on theexpression of the word error probability at the output of theouter decoder as a function of the error statistics at the outputof the turbo decoder estimated through simulation. The proposedtechnique yields results that depend on the ...
Queste note sono rivolte agli studenti del corso di Trasmissione sul Canale Radiomobile. L'o... more Queste note sono rivolte agli studenti del corso di Trasmissione sul Canale Radiomobile. L'obiettivoe quello di fornire una esposizione sintetica delle informazioni necessarie per lo studio delle tecniche trasmissive impiegate nei sistemi radiomobili cellulari. A tal fine, sono analizzate diverse tecniche utilizzate nei sistemi radiomobili cellulari fino alla terza generazione. iii
Proc. 7th Canadian Workshop Information Theory, 2001
Abstract-In this paper, we propose a simple stopping criterion applied to the iterative decoding ... more Abstract-In this paper, we propose a simple stopping criterion applied to the iterative decoding algorithm used in concatenated codes with interleaver. Differently from other criteria reported in literature, which attempt to reduce the average number of iterations with little performance degradation, the proposed stopping rules try to minimized the Bit Error Probability (BEP), together with number of iterations.
Proc. Int. Symp. on Turbo Codes and Related Topics, Brest, France, Sep 1, 2000
Abstract; A digital signal processor (DSP) implementation of the new CCSDS standard for telemetry... more Abstract; A digital signal processor (DSP) implementation of the new CCSDS standard for telemetry channel coding, presently at an advanced stage of discussion, based on turbo codes is described. Using the recent Texas Instrument TMS320C6201 DSP, and a carefully optimized assembly language program, a universal decoder realizing all required rates and block lengths of the standard has been implemented, capable of decoding at a speed of nearly 60 Kbit/s with 10 iterations of the decoding strategy based on the optimum SISO ...
IEEE Communications Letters, 2016
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Papers by Alberto Perotti