Design and performances evaluation of new Costas-based radar waveforms with pulse coding diversity

Costas codes are a variant of pulse compression waveforms, largely studied for their attractive time-frequency properties. Their 'thumbtack-like' ambiguity function (AF) makes them highly suitable for delay and Doppler estimation, in radar and sonar applications. However, this behaviour depends heavily on the length of the code: the improvement in delay-Doppler resolutions and AF sidelobes level needs an increase in the size of the code. In this study, designs that allow good performance without increasing the size of the code are proposed. They are based on a modification of Costas codes by widening frequency separation between hops and replacing rectangular pulses by other waveforms. This will lead to a removal of autocorrelation function grating lobes that normally appear when frequency separation is increased. The originality of the work lies in the proposal of diversified pulse waveforms, such as phase codes, Slepian sequences, and other Costas codes, to encode main Costas pulses. A performance comparison of the proposed approaches is supplied. Such waveforms could also be of interest for applications where waveform diversity is desired

Pulse compression waveforms design and Cross-ambiguity processing for Radar applications

2014 International Symposium on signal, Image, Video and Communications - ISIVC 2014, Marrakech, Maroc, 19-/11/2014 - 22/11/2014Radar waveforms design is an important step to design a hole radar system. In this paper, several waveforms based on modified Costas codes are used. The properties and performances are tested and compared. We propose a detection based on cross-ambiguity calculation for these waveforms. Indeed, such a processing is interesting when delay and Doppler should be estimated. The performances are evaluated in several scenarios in presence of noise and multiple targets. The waveforms are also tested on real experimentation hardware

Short Range Radar Based on UWB Technology

ISBN 978-953-307-029-

Pilot-Aided Sequential Monte Carlo Estimation of Phase Distortions and Transmitted Symbols in Multicarrier Systems

We address the challenging problem of the joint estimation of transmitted symbols and phase distortions in standardized multicarrier systems, including pilot or virtual subcarriers. These subcarriers create time correlation on the useful transmitted OFDM signal that we propose to take into account by an autoregressive model. Because the phase distortions are nonlinear, we set the joint estimation algorithm on the framework of the Sequential Monte Carlo methods. Simulation results are provided in terms of bit error rate (BER) and mean square error (MSE); they highlight the efficiency and the robustness of the estimator.Peer Reviewe

Register file reliability enhancement through adjacent narrow-width exploitation

Due to the increasing vulnerability of CMOS circuits, new generations of microprocessors require an inevitable focus on reliability issues. As the Register File (RF) constitutes a critical element within the processor pipeline, it is mandatory to enhance the RF reliability to develop fault tolerant architectures. This paper proposes Adjacent Register Hardened RF (ARH), a new RF architecture that exploits the adjacent byte-level narrow-width values for hardening registers at runtime. Registers are paired together by some special switches referred to as joiners. Dummy sign bits of each register are used to keep redundant data of its counterpart register. We use 7T/14T SRAM cell [6] to combine redundant bits together to make a single bit cell which is, by far, more resilient against faults. Our simulations show that with 3% to 12% power overhead and 10% to 20% increase in area, in comparison to baseline RF, we can obtain up to 80% reduction in soft error rate (SER). © 2016 IEEE

IR-UWB Cognitive Radio System Based on the M-OAM Modulations

Communication systems plays decisive role in the evolution of the transport field, and during the last years, requests to have the safest and most efficient transport modes has been expressed by users. The use of the ultra-wideband (UWB) technique can satisfy such a need. UWB offers numerous advantages such as: the large offered bandwidth, the signal flexibility, the quality of service, the transmission power and the limited cost. In this paper, a new system dedicated to the domain of transport, based on UWB technology is presented. The implementation of the new modulation M-OAM (Orthogonal Amplitude Modulation) which is based on the use of original mathematical tools called Modified Gegenbauer functions (MGF), derived from orthogonal polynomials, increases the data rate flow and enhances the robustness ensured by UWB communication for multimedia and transport applications. With the purpose of improving the functioning of the communication system and ensuring the very high data rate, this work consists in combination of UWB and cognitive radio technologies in order to develop an adapted and efficient universal receiver. This receiver is able to detect the signal arrival and identify the coding parameters used in the transmission so as to be adapted to them automatically. The receiver requires intelligent capacities of observation, learning and decision, therefore, our conception is based on the concept of the cognitive radio which is characterized with the ability to detect the presence of the signal. In this paper, we present the principle of the modulation M-OAM, the waveforms used in our system, and the method which allows the receiver to identify the type of the used modulation

Time-Reversal UWB Wireless Communication-Based Train Control in Tunnel

This paper reports an evaluation of UWB radio technology and Time-Reversal (TR) technique in tunnel environments for train-to-wayside communication. UWB technology has the potential to offer simultaneous ground-totrain communication, train location and obstacle detection in front of the trains. Time-Reversal channel pre-filtering facilitates signal detection and helps reduce interference. Thus, UWB-TR combination provides a challenging, economically sensible, as well as technically effective alternative solution to existing signaling technologies used in urban transport systems. This paper deals with deterministic channel modeling and its characterization in tunnel environment. It reports simulation performance evaluation of UWB-TR combinations in the developed channel model