Abstract The China Seismo‐Electromagnetic Satellite (CSES) space mission—also known as Limadou in Italian—is a scientific collaboration between China and Italy that aims to investigate the structure and dynamics of the iono/magnetosphere, and in particular to study the possible correlation of perturbations to the occurrence of high‐magnitude seismic events. The Chinese satellite houses the Italian high‐energy particle detector (HEPD), an apparatus composed of a silicon tracker and a calorimeter system, which detects electrons and protons in the energy ranges 3–100 and 30–200 MeV, respectively. The satellite was launched on February 2, 2018; after a commissioning phase dedicated to the setting of an optimal configuration, HEPD is fully operational since July 28, 2018. After a general overview of the CSES‐Limadou mission, this article presents the structure of the HEPD apparatus and describes the design and implementation of the software for the embedded computer system that is responsible for HEPD management. The onboard software runs on the digital signal processors of two electronic boards (CPU and data acquisition), monitors system status, handles instrument data acquisition, performs periodic calibration of the subdetectors, performs data compression, and communicates with the satellite. An overview of HEPD in‐flight operations and performance is given in the last section.

In this paper we describe a new instrument named ALISEO (Aerospace Leap-frog Imaging Stationary Interferometer for Earth Observation), which belongs to the class of the ¿stationary interferometers¿. ALISEO has been selected as the main payload for a novel Italian Space Agency (ASI) optical mission based on a micro-satellite (MIOSat) with steering capability. The mission is constituted by a micro-satellite equipped with advanced payloads, among which there are an extensible telescope, a MEMS Mach-Zehnder non-imaging interferometer, and ALISEO. MIOSat is expected to provide the scientific community with the technological demonstration of this new remote sensing technology.

The paper presents a Euclidean distance maximum likelihood sequence estimation (MLSE) receiver, based on the Viterbi algorithm (VA), suitable for fading and noisy communications channels, as that specified by the Group Special Mobiles (GSM). In a mobile cellular system, the fast varying channel characteristics, due to the fading and Doppler effects, require adaptive methods to update the channel coefficients to the MLSE receiver. The proposed technique continuously estimates the channel characteristics directly within the metric calculation of the VA. At each step of the VA, the sequence associated to the path with the best metric value (minimum-survivor method) among the survivor paths is used to update the channel estimate (employing conventional adaptive algorithms) throughout the entire informative sequence. However, the detection of the transmitted data sequence is performed by the VA only at the end of each burst. The proposed technique allows simpler receiver implementation and the simulation results show a good performance of this adaptive MLSE receiver in typical GSM environments.

Neural networks have been successfully applied in many fields thanks to their learning and generalization capabilities and to the parallel processing and fault tolerance properties. Typical applications concern images processing, pattern recognition and digital signal processing, such as adaptive filtering and channel equalization. The authors propose the use of neural networks as digital receivers for continuous phase modulation (CPM). Simulation results refer to the European GSM digital cellular radio system. The neural receiver performance has been evaluated for coherent detection, considering an additive white Gaussian noise (AWGN) channel and compared with a maximum likelihood sequences estimator (MLSE) receiver based on the Viterbi algorithm. The paper also presents a hardware implementation of the proposed network based on a digital signal processor (DSP) and on a programmable gate array (PGA).>

A simplified structure concerning the implementation of an adaptive digital receiver suitable for the pan-European cellular system Group Special Mobile (GSM) is described. In the GSM system, the performance of the received information is strongly affected by the multipath typical of the mobile communications channel. The proposed maximum-likelihood sequence estimation (MLSE) receiver based on the Viterbi algorithm compensates for selective distortion due to the multipath propagation and Doppler shift also in the case of fast channel variations using an adaptive tracking mode method.>

We have investigated the problem of track finding with a recurrent neural network algorithm based on the Hopfield model and considered the possibility of a hardware implementation with DSP’s. Starting from a set of signal points we define track segments and set a cut on the length to keep the size of the network reasonable. Those segments surviving the cut are associated to neurons. A geometric coupling of neighbouring segments is used to select smooth combinations of them. Given random initial conditions the network converges to a solution. The method may be applied to a variety of curves.

The authors present a multi-DSP (digital signal processing) system based on commercial chips. The structure is a MIMD (multiple-instruction multiple-data) machine with a data-driven organization. A locally parallel link based on a memory shared between two adjacent nodes assures the asynchronous exchange of data. The system is also characterized by a global serial channel useful for program-loading purposes and noncritical data paths. A mathematical model is used to evaluate the performance of the multi-DSP system. The apparatus is used in ultrasound Doppler parameter estimation but the processing architecture is suitable for general real-time applications.>

Digital signal processing has several and very interesting applications in the aids for disabled persons. In the case of communication aids for the blind the use of microcomputers and of signal processing techniques [e.g. voice synthesis, image processing and computer graphics] makes possible the production of integrated communication aids, using which the blind can exchange information, both character based or graphical, with sigthed persons. Two peripherals, designed for this purpose, are briefly described: a speech synthesizer for the Italian language with unrestricted dictionary and a plotter which is able to produce embossed drawings on normal printer paper. The use of these peripherals to solve the proposed problems is discussed, showing that a very important point in this application is the efficiency of the interaction software.