21 research outputs found
Bistatic OFDM-based Joint Radar-Communication: Synchronization, Data Communication and Sensing
Doppler Shift Tolerance of Accumulation and Outer Coding in MIMO-PMCW Radar
Phase-modulated continuous wave (PMCW) has been widely regarded as a promising modulation scheme for radar systems, e.g., in highly automated driving (HAD) applications. Although the so-called outer coding can efficiently enable the multiple-input-multiple-output (MIMO) operation of PMCW-based radar systems, the yielded processing gain in this multiplexing approach may be reduced at increasing Doppler shifts. In this context, this letter introduces a normalized Doppler shift parameter that enables predicting the Doppler-shift-induced degradation of the processing gain in a MIMO-PMCW radar system. Finally, simulation and measurement results confirm the usefulness of the introduced parameter in desigining MIMO-PMCW radars
Bistatic OFDM-based Joint Radar-Communication: Synchronization, Data Communication and Sensing
This article introduces a bistatic joint radar-communication (RadCom) system
based on orthogonal frequency-division multiplexing (OFDM). In this context,
the adopted OFDM frame structure is described and system model encompassing
time, frequency, and sampling synchronization mismatches between the
transmitter and receiver of the bistatic system is outlined. Next, the signal
processing approaches for synchronization and communication are discussed, and
radar sensing processing approaches using either only pilots or a reconstructed
OFDM frame based on the estimated receive communication data are presented.
Finally, proof-of-concept measurement results are presented to validate the
investigated system and a trade-off between frame size and the performance of
the aforementioned processing steps is observed.Comment: Accepted for presentation at the focused session "Joint Communication
and Radar Sensing - a step towards 6G'' of the EuMW 202
Enabling Joint Radar-Communication Operation in Shift Register-Based PMCW Radars
This article introduces adaptations to the conventional frame structure in
binary phase-modulated continuous wave (PMCW) radars with sequence generation
via linear-feedbck shift registers and additional processing steps to enable
joint radar-communication (RadCom) operation. In this context, a preamble
structure based on pseudorandom binary sequences (PRBSs) that is compatible
with existing synchronization algorithms is outlined, and the allocation of
pilot PRBS blocks is discussed. Finally, results from proof-of-concept
measurements are presented to illustrate the effects of the choice of system
and signal parameters and validate the investigated PMCW-based RadCom system
and synchronization strategy.Comment: Accepted for presentation at the focused session "Automotive PMCW
Radars'' of the EuMW 202
Doppler Shift Tolerance of Typical Pseudorandom Binary Sequences in PMCW Radar
In the context of all-digital radar systems, phase-modulated continuous wave (PMCW) based on pseudorandom binary sequences (PRBSs) appears to be a prominent candidate modulation scheme for applications such as autonomous driving. Among the reasons for its candidacy are its simplified transmitter architecture and lower linearity requirements (e.g., compared to orthogonal-frequency division multiplexing radars), as well as its high velocity unambiguity and multiple-input multiple-output operation capability, all of which are characteristic of digital radars. For appropriate operation of a PMCW radar, choosing a PRBS whose periodic autocorrelation function (PACF) has low sidelobes and high robustness to Doppler shifts is paramount. In this sense, this article performs an analysis of Doppler shift tolerance of the PACFs of typically adopted PRBSs in PMCW radar systems supported by simulation and measurement results. To accurately measure the Doppler-shift-induced degradation of PACFs, peak power loss ratio (PPLR), peak sidelobe level ratio (PSLR), and integrated-sidelobe level ratio (ISLR) were used as metrics. Furthermore, to account for effects on targets whose ranges are not multiples of the range resolution, oversampled PACFs are analyzed
USO DE TECNOLOGIA NA INTERVENÇÃO PSIQUIÁTRICA: ANÁLISE DE REVISÃO SISTEMÁTICA
Technological advances in psychiatric intervention represent a positive revolution, but require an ethical and careful approach. It is essential to reconcile the therapeutic benefits offered by technology with the preservation of privacy and the ethical management of sensitive information associated with mental health. The participatory development of these technologies is key to ensuring that the alliance between technology and mental health is conducted responsibly and effectively. The aim of this study was to reflect on the impact of the use of technology in psychiatric intervention. In order to achieve this goal, we carried out a systematic literature review using the Scielo, Lilacs and Medline data platforms. In summary, after a qualitative analysis of the results, we observed a significant impact of technology on psychiatric care, with emphasis on its potential to improve access to mental health services, offer continuous support to patients and assist professionals in the assessment and treatment of psychiatric disorders. Telepsychiatry, in particular, is presented as an effective tool, eliminating geographical barriers and increasing accessibility to services, but the conclusion also warns of ethical challenges, privacy and disparities in access that need to be addressed to ensure an equitable and effective implementation of these technologies.Os avanços tecnológicos na intervenção psiquiátrica representam uma revolução positiva, mas demandam uma abordagem ética e cuidadosa. É fundamental conciliar os benefícios terapêuticos oferecidos pela tecnologia com a preservação da privacidade e o gerenciamento ético das informações sensíveis associadas à saúde mental. O desenvolvimento participativo dessas tecnologias é fundamental para garantir que a aliança entre tecnologia e saúde mental seja conduzida de maneira responsável e eficaz. Trata-se de um estudo cujo objetivo foi refletir sobre o impacto do uso de tecnologia na intervenção psiquiátrica. Com o intuito de atingir essa meta, realizamos uma revisão sistemática da literatura, utilizando as plataformas de dados Scielo, Lilacs e Medline. Em resumo, após análise qualitativa dos resultados, observou-se que Em resumo, se observa o impacto significativo da tecnologia no atendimento psiquiátrico, com destaque no seu potencial para melhorar o acesso aos serviços de saúde mental, oferecer suporte contínuo aos pacientes e auxiliar os profissionais na avaliação e tratamento de transtornos psiquiátricos. A telepsiquiatria, em particular, é apresentada como uma ferramenta eficaz, eliminando barreiras geográficas e aumentando a acessibilidade aos serviços, mas a conclusão também alerta para desafios éticos, de privacidade e disparidades no acesso que precisam ser abordados para garantir uma implementação equitativa e eficaz dessas tecnologias