Identification and authentication procedures are really important aspects when talking about payments. Nowadays, credit and debit cards are the target for thieves since they can be easily cloned. One of the main fraud sources is represented by the Point Of Sale, the well-known POS. The paper describes an innovative payment system studied, developed and tested within the GAL-PMI Project, an initiative funded by the Industry Division of the Piedmont Region. The system provides users with a user- friendly application to perform payments by means of personal mobile devices like PDA or smartphone, using Global Navigation Satellite Systems as the baseline to increase security aspects. The paper gives an overview of this payment system architecture, going through the technological infrastructure that is based on navigation and communication capabilities. Finally, the paper presents a real test case, which has been set-up to demonstrate how security aspects can be improved within identification and authentication processes during payments at gas station.

This paper has the goal to present the advancements in the design, development and test of a hybrid NAV/COM platform tailored to emergency operations. In particular, the system here discussed, named NICE - navigation in case of emergency, has been defined with the support of the alpine rescue team members of the Piemonte Region (Italy) that contributed towards the system requirements definition as well as the system operational tests. It is important to highlight that NICE is a technology created to support the management of the rescuers in the field (the mountain environment). It is a network-based positioning system exploiting the advantages of both the european geostationary navigation overlay system (EGNOS) associated to GPS and the available VHF communication infrastructure. The positioning system is based on the raw GPS measurements collected by the user terminal and transmitted to a local element by VHF radio channels (or GPRS when available). Present R&D activities are also considering the integration of NICE with the terrestrial trunked radio (TETRA) communication infrastructure in use by several European civil protection agencies.

The advent of the Galileo system in Europe and the modernization plans for global positioning system (GPS) are giving a strong impulse to development of global navigation satellite systems (GNSS). The availability of a variety of new signals is boosting the growth of new services and applications. The next generation of receivers will have to deal with signals in different bandwidths with different modulation schemes. In such a context the reconfigurability offered by software defined radio (SDR) technologies, employing programmable hardware like field programmable gate arrays (FPGAs) and digital signal processors (DSPs), can play an important role. The paper presents a case-study of an efficient hardware/software partitioning for the baseband processor and discusses in detail how to meet the real-time constraints. Finally some results concerning the implementation of the proposed architecture on a prototyping board are given.

The development of context-aware services is strongly pushing the integration of positioning capabilities in personal communication terminals, with particular attention to third generation systems (UMTS). On the other hand, the synergy between communication and positioning can be of aid for this latter easing the acquisition and tracking of weak signals, and improving performance. In order to provide the user of reliable positioning solutions a suitable receiver dealing both with navigation and communication signal is required. A new hybrid positioning algorithm and a joint receiver structure able to receive and process signals broadcast from both navigation satellite systems and cellular radio networks, is presented, discussing the impact on the joint receiver.

In this letter, we view the implicit unequal error protection observed in the asymptotic performance of most turbo codes as an impetus to the formulation of a rate-allocation problem, associated with the distribution of a fixed quota of coded bits in the trellis sections of the upper and lower recursive systematic convolutional codes of the turbo-code structure. We then present an effective greedy approach for solving this rate-allocation problem via a two-phase process of puncturing and repetition coding, resulting in the improvement of the asymptotic performance of the code and lowering of its error floor. Sample simulation results are presented, confirming the potential gains of the approach.

In this paper, we address the issue of pruning (i.e., shortening) a given interleaver in a parallel concatenated convolutional code (PCCC). The principle goal of pruning is that of construction of variable-length and hence delay interleavers with application to PCCC, using the same structure (possibly in hardware) of the interleaver and deinterleaver units. As a side benefit, it is sometimes possible to reduce the interleaver length and hence delay for nearly the same and sometimes even better asymptotic performance. In particular, we present a systematic technique for interleaver pruning and demonstrate the average optimality of the strategy. Sample simulation results are presented confirming the average optimality of the proposed scheme.

In this correspondence, we present a technique for generation of linear subcodes of a given turbo code with better distance spectrum than the original mother turbo code, via an iterative process of trace-bit injection which minimally reduces code rate, followed by selective puncturing that allows recovery of the rate loss incurred during the trace-bit injection. The technique allows for asymptotic performance improvement of any linear turbo code. In effect, we trim the distance spectrum of a turbo code via elimination of the low distance and/or high multiplicity codewords from the output space of the code. To this end, we perform a greedy minimization of a cost function closely related to the asymptotic bit error probability (or frame error probability) of the code. This improves the performance of the code everywhere, but its main impact is a reduction in the error floor of the turbo code which is important for delay constrained applications employing short interleavers.

This paper looks at the problem of the implicit unequal error protection observed in the asymptotic performance of most turbo codes. In particular we propose a new formulation of the rate allocation problem associated with the distribution of a fixed quota of coded bits in the trellis sections of the upper and lower recursive systematic convolutional (RSC) codes of the turbo code structure. The main goal of this work is the design of an effective greedy approach for solving this rate allocation problem via a two phase process of puncturing and repetition coding. Sample simulation results confirm that the asymptotic performances in terms of error floor are improved confirming the potential gain of this approach.

This paper looks at the problem of optimizing a given parallel concatenated convolutional code (PCCC) via an iterative process of trace-bit injection which minimally reduces the code rate, followed by selective puncturing that allows recovery of the rate loss incurred during the trace-bit injection. The technique allows for optimization of any linear PCCC. The optimization is in the sense of trimming the distance spectrum of the overall PCCC via elimination of the low distance and/or high multiplicity codewords from the output space of the code, using a cost function closely related to the asymptotic bit error probability of the code. This improves the performance of the code everywhere, but the main impact of the optimization process is a reduction in the error floor of the PCCC.

Abstract The geographical location of a wireless device is acquiring a significant importance under the boost of innovative applications in the wireless market, and under the research activities related to the development of a new generation of Global Navigation Satellite Systems (GNSS). In the US a new phase of the Global Positioning System is foreseen, and Europe has decided to proceed with the Galileo program. In addition, different government institutions worldwide are working toward the definition of navigation plans, and regulations will set as mandatory the location identification of mobile users in emergency situations (US E‐911 law and the European E‐112 directive). Considering all the navigation/positioning systems and techniques that will be available in the near future, it is clear that a central role will be played by the user handset; in fact, if navigation signals from different sources will be available, the unique possibility to obtain the best navigation performance from the user perspective will be the employment of enhanced receivers able to fuse different data. With this aim, this paper presents the design of an innovative navigation receiver based on Software Defined Radio (SDR) technology. The reconfigurability and flexibility issues are guaranteed by the use of reprogrammable high‐speed hardware (FPGA—Field Programmable Gate Array and DSP—Digital Signal Processor) and thus a deep integration at the raw signal level between GPS and the future Galileo has been obtained. The interoperability issue among different systems is then solved at the receiver level. This paper discusses the implementation of a baseline architecture of a reconfigurable GNSS receiver over a FPGA + DSP prototype platform. The receiver is able to deal with different input Signals‐In‐Space (SIS), and can operate with present GPS ranging signals or with the future Galileo SIS. Copyright © 2002 John Wiley & Sons, Ltd.