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1.
Sensors (Basel) ; 23(18)2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37765850

RESUMEN

The intelligent reflecting surface (IRS) is a two-dimensional (2D) surface with a programmable structure and is composed of many arrays. The arrays are used to supervise electromagnetic wave propagation by altering the electric and magnetic properties of the 2D surface. IRS can influentially convert wireless channels to very effectively enhance spectral efficiency (SE) and communication performance in wireless systems. However, proper channel information is necessary to realize the IRS anticipated gains. The conventional technique has been taken into consideration in recent attempts to fix this issue, which is straightforward but not ideal. A deep learning model which is called the long short-term memory (Bi-LSTM) model can tackle this issue due to its good learning capability and it plays a vital role in enhancing SE. Bi-LSTM can collect data from both forward and backward directions simultaneously to provide improved prediction accuracy. Because of the tremendous benefits of the Bi-LSTM model, in this paper, an IRS-assisted Bi-LSTM model-based multi-user multiple input single output downlink system is proposed for SE improvement. A Wiener filter is used to determine the optimal phase of each IRS element. In the simulation results, the proposed system is compared with other DL models and methods for the SE performance evaluation. The model exhibits satisfactory SE performance with a different signal-to-noise ratio compared to other schemes in the online phase.

2.
Asian Biomed (Res Rev News) ; 17(1): 39-42, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37706054

RESUMEN

Background: The urine immunochromatographic assay is a useful screening tool for patients suspected of acute drug intoxication in emergency conditions. Diphenhydramine intoxication shows symptoms similar to those of tricyclic antidepressant (TCA) intoxication. Case presentation: We examined a case of diphenhydramine intoxication showing cerebellar ataxia and prolonged false positive results for TCA in the urine. The urine TCA test showed persistently positive results even 60 h after the patient's initial drug screening. We observed negative conversion 90 h after the initial drug screening. Discussion: Considering the similarities of clinical symptoms between diphenhydramine and TCA intoxication, emergency physicians should consider the possibility of cross-reactivity in the diagnosis of a patient with unknown acute drug intoxication showing positive results of TCA immunochromatographic assay in the urine. Conclusion: The present case suggests that diphenhydramine overdose may cause cerebellar ataxia and show prolonged cross-reactivity as TCA in the urine.

3.
Sensors (Basel) ; 23(2)2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36679539

RESUMEN

Visible light communication (VLC) has contributed new unused spectrum in addition to the traditional radio frequency communication and can play a significant role in wireless communication. The adaptation of VLC technology enhances wireless connectivity both in indoor and outdoor environments. Multiple-input multiple-output (MIMO) communication has been an efficient technique for increasing wireless communications system capacity and performance. With the advantages of MIMO techniques, VLC can achieve an additional degree of freedom. In this paper, we systematically perform a survey of the existing work based on MIMO VLC. We categorize the types of different MIMO techniques, and a brief description is given. Different problem-solving approaches are given in the subsequent sections. In addition, machine learning approaches are also discussed in sufficient detail. Finally, we identify the future study direction for MIMO-based communication in VLC.


Asunto(s)
Aclimatación , Aprendizaje Automático , Tecnología de la Información , Luz
4.
PLoS Genet ; 18(9): e1010404, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36121845

RESUMEN

Most somatic mutations that arise during normal development are present at low levels in single or multiple tissues depending on the developmental stage and affected organs. However, the effect of human developmental stages or mutations of different organs on the features of somatic mutations is still unclear. Here, we performed a systemic and comprehensive analysis of low-level somatic mutations using deep whole-exome sequencing (average read depth ~500×) of 498 multiple organ tissues with matched controls from 190 individuals. Our results showed that early clone-forming mutations shared between multiple organs were lower in number but showed higher allele frequencies than late clone-forming mutations [0.54 vs. 5.83 variants per individual; 6.17% vs. 1.5% variant allele frequency (VAF)] along with less nonsynonymous mutations and lower functional impacts. Additionally, early and late clone-forming mutations had unique mutational signatures that were distinct from mutations that originated from tumors. Compared with early clone-forming mutations that showed a clock-like signature across all organs or tissues studied, late clone-forming mutations showed organ, tissue, and cell-type specificity in the mutation counts, VAFs, and mutational signatures. In particular, analysis of brain somatic mutations showed a bimodal occurrence and temporal-lobe-specific signature. These findings provide new insights into the features of somatic mosaicism that are dependent on developmental stage and brain regions.


Asunto(s)
Mosaicismo , Neoplasias , Frecuencia de los Genes , Humanos , Mutación , Neoplasias/genética , Secuenciación del Exoma
5.
Technol Health Care ; 28(S1): 487-497, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32364181

RESUMEN

BACKGROUND: Biomedical engineers in particular require fast and powerful data processing systems to process computerized tomography and magnetic resonance imaging scans and other medical imaging technologies. However, current computer data processing technologies are unable to satisfy such requirements. A promising approach to addressing these limitations is processing in memory (PIM). Unfortunately, several issues, such as the compatibility and interconnection of PIM with legacy systems, still remain. OBJECTIVE: This paper proposes a standard memory bus-based PIM interface for medical image processing and a PIM platform. The proposed PIM interface can overcome problems of compatibility with legacy systems. METHODS: We will adapt an embedded system based on a commercial application processor (AP) to a medical image system to verify the functions and the performance of the proposed PIM interface. Using the PIM platform, we apply the proposed PIM interface and the AP to execute an image processing program, measure the image processing times, and compare the results of the measurements. RESULTS: Experimental results show that while the functions of the proposed PIM interface are normal, the processing time of PIM is more than 81% faster than that of the AP. CONCLUSION: The experimental results prove that the proposed PIM interface is able to solve problems of compatibility with legacy systems. We foresee that not only the medical image processing field but also a number of academic fields and professional sectors will use PIM in their data-intensive applications.


Asunto(s)
Procesamiento Automatizado de Datos/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Humanos , Factores de Tiempo
6.
Science ; 365(6452): 491-494, 2019 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-31371614

RESUMEN

A major challenge for implantable medical systems is the inclusion or reliable delivery of electrical power. We use ultrasound to deliver mechanical energy through skin and liquids and demonstrate a thin implantable vibrating triboelectric generator able to effectively harvest it. The ultrasound can induce micrometer-scale displacement of a polymer thin membrane to generate electrical energy through contact electrification. We recharge a lithium-ion battery at a rate of 166 microcoulombs per second in water. The voltage and current generated ex vivo by ultrasound energy transfer reached 2.4 volts and 156 microamps under porcine tissue. These findings show that a capacitive triboelectric electret is the first technology able to compete with piezoelectricity to harvest ultrasound in vivo and to power medical implants.


Asunto(s)
Fuentes de Energía Bioeléctrica , Electricidad , Prótesis e Implantes , Ondas Ultrasónicas , Animales , Piel , Porcinos
7.
Sensors (Basel) ; 19(14)2019 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-31336590

RESUMEN

Most approaches for moving object detection (MOD) based on computer vision are limited to stationary camera environments. In advanced driver assistance systems (ADAS), however, ego-motion is added to image frames owing to the use of a moving camera. This results in mixed motion in the image frames and makes it difficult to classify target objects and background. In this paper, we propose an efficient MOD algorithm that can cope with moving camera environments. In addition, we present a hardware design and implementation results for the real-time processing of the proposed algorithm. The proposed moving object detector was designed using hardware description language (HDL) and its real-time performance was evaluated using an FPGA based test system. Experimental results demonstrate that our design achieves better detection performance than existing MOD systems. The proposed moving object detector was implemented with 13.2K logic slices, 104 DSP48s, and 163 BRAM and can support real-time processing of 30 fps at an operating frequency of 200 MHz.

8.
Cancers (Basel) ; 11(4)2019 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-30987235

RESUMEN

Complement factor H (CFH) is a fluid phase regulator of complement proteins and functions to prevent complement attack and immune surveillance. CFH is known to inactivate therapeutic antibody-dependent complement-mediated cellular cytotoxicity. We found that CFH was highly expressed in human lung cancer cells and tissues. To investigate mechanisms of CFH upregulation, we searched for a CFH transcription factor and its regulatory factors. First, signal transducer and activator of transcription 4 (STAT4) expression patterns coincided with CFH expression patterns in lung cancer tissues. Knockdown of STAT4 led to decreased CFH secretion from lung cancer cells. STAT4 bound directly to the CFH promoter, as demonstrated by luciferase reporter assay, electrophoretic mobility shift assay (EMSA), and chromatin immunoprecipitation (ChIP) assay, suggesting that STAT4 is a transcription factor for CFH. In addition, a low level of suppressors of cytokine signaling (SOCS)-1/3, a Janus kinase (JAK) inhibitor, was observed in lung cancer cells and its transfection decreased CFH protein levels and promoter activity. Unexpectedly, the low level of SOCS-1/3 was not due to epigenetic silencing. Instead, differential methylation was found on the regulatory region of STAT4 between normal and lung cancer cells. In conclusion, our results demonstrated that CFH is upregulated by constitutive activation of STAT4, which is accounted for by SOCS silencing in lung cancer cells.

9.
Diabetes Obes Metab ; 20(10): 2408-2415, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29862619

RESUMEN

AIM: To evaluate the efficacy and safety of ipragliflozin vs placebo as add-on therapy to metformin and sitagliptin in Korean patients with type 2 diabetes mellitus (T2DM). METHODS: This double-blind, placebo-controlled, multi-centre, phase III study was conducted in Korea in 2015 to 2017. Patients were randomized to receive either ipragliflozin 50 mg/day or placebo once daily for 24 weeks in addition to metformin and sitagliptin. The primary endpoint was the change in glycated haemoglobin (HbA1c) from baseline to end of treatment (EOT). RESULTS: In total, 143 patients were randomized and 139 were included in efficacy analyses (ipragliflozin: 73, placebo: 66). Baseline mean (SD) HbA1c levels were 7.90 (0.69)% for ipragliflozin add-on and 7.92 (0.79)% for placebo. The corresponding mean (SD) changes from baseline to EOT were -0.79 (0.59)% and 0.03 (0.84)%, respectively, in favour of ipragliflozin (adjusted mean difference -0.83% [95% CI -1.07 to -0.59]; P < .0001). More ipragliflozin-treated patients than placebo-treated patients achieved HbA1c target levels of <7.0% (44.4% vs 12.1%) and < 6.5% (12.5% vs 1.5%) at EOT (P < .05 for both). Fasting plasma glucose, fasting serum insulin, body weight and homeostatic model assessment of insulin resistance decreased significantly at EOT, in favour of ipragliflozin (adjusted mean difference -1.64 mmol/L, -1.50 µU/mL, -1.72 kg, and -0.99, respectively; P < .05 for all). Adverse event rates were similar between groups (ipragliflozin: 51.4%; placebo: 50.0%). No previously unreported safety concerns were noted. CONCLUSIONS: Ipragliflozin as add-on to metformin and sitagliptin significantly improved glycaemic variables and demonstrated a good safety profile in Korean patients with inadequately controlled T2DM.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Glucósidos/administración & dosificación , Metformina/administración & dosificación , Fosfato de Sitagliptina/administración & dosificación , Tiofenos/administración & dosificación , Adulto , Anciano , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/sangre , Método Doble Ciego , Quimioterapia Combinada , Femenino , Glucósidos/efectos adversos , Hemoglobina Glucada/efectos de los fármacos , Hemoglobina Glucada/metabolismo , Humanos , Masculino , Metformina/efectos adversos , Persona de Mediana Edad , República de Corea , Fosfato de Sitagliptina/efectos adversos , Tiofenos/efectos adversos , Resultado del Tratamiento , Adulto Joven
11.
Ann Surg Treat Res ; 94(1): 19-25, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29333422

RESUMEN

PURPOSE: Emerging evidence indicates that runt-related transcription factor 3 (RUNX3) is an important tumor suppressor gene in several cancer types, including colorectal cancer (CRC). However, the clinical significance of RUNX3 inactivation in CRC remains unclear. The aim of this study was to examine the correlation between clinicopathologic factors and RUNX3 hypermethylation/expression in CRC. METHODS: Sixty-two CRC patients who were treated at the Soonchunhyang University College of Medicine were recruited in this study. The hypermethylation of CpG islands in the RUNX3 promoter and the expression of RUNX3 mRNA were identified by methylation-specific polymerase chain reaction (PCR) and reverse transcriptase-PCR, respectively. The expression of RUNX3 was determined by immunohistochemical staining. RESULTS: Of the 62 CRC tissue samples, 20 (32.3%) presented hypermethylated RUNX3 promoters. Aberrant RUNX3 hypermethylation was found to be associated with vascular (P = 0.006) and lymphatic (P = 0.002) invasion. Hypermethylation of RUNX3 was associated with poor survival outcomes (P = 0.038). However, expression of RUNX3 was not a prognostic factor (P = 0.363). CONCLUSION: Hypermethylation of RUNX3 may be a predictor of a poor prognosis in CRC.

12.
Oncol Lett ; 14(2): 1609-1614, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28789386

RESUMEN

Mutations in the promoter region of telomerase reverse transcriptase (TERT) and alterations in telomere length (TL) have been the focus of research in various types of cancer. In the present study, the frequency and clinical characteristics of TERT promoter mutations and TL were studied in non-small cell lung cancers (NSCLC). TERT promoter mutations and TL were analyzed in 188 patients using DNA sequencing and the reverse transcription-quantitative polymerase chain reaction, respectively. The TERT promoter mutation rate was observed to be 2.2% (4/188 NSCLC cases), and it was significantly associated with regional lymph node invasion (P<0.001). No significant difference in TL was observed between the patients with and without TERT promoter mutations. TL was decreased in males (P=0.058 vs. females) and smokers (P=0.008 vs. non-smokers). Survival analyses demonstrated poor prognoses for patients with NSCLC with TERT promoter mutations (P<0.001). Multivariate survival analyses demonstrated that TERT promoter mutations were an independent prognostic marker for poor overall survival (P=0.045). The results of the present study demonstrated that TERT promoter mutation was not frequent in NSCLC; however, it may have value as a prognostic marker in NSCLC.

13.
Mar Pollut Bull ; 114(2): 837-842, 2017 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-27847166

RESUMEN

In order to prove that porous piles are effective in remediating muddy tidal flat sediments and increasing the biomass, field experiments were carried out at the tidal flat of a brackish river located in Hiroshima City, Japan. Porous piles with a diameter of 16cm and height of 50cm were installed in the muddy sediment that covers the sand layer of the tidal flat. After installation, concentrations of dissolved oxygen in interstitial water in and around the porous piles increased to a maximum concentration of 6mg/l due to enhancement of the groundwater flow. The increase of dissolved oxygen in the interstitial water produced a decrease in the concentration of ammonia and an increase in the individual number of benthos at the porous pile site. From these results, we concluded that the porous pile is an effective technology for remediation of muddy tidal flats.


Asunto(s)
Restauración y Remediación Ambiental/métodos , Sedimentos Geológicos/química , Agua Subterránea/química , Oxígeno/análisis , Movimientos del Agua , Japón , Proyectos Piloto , Porosidad , Propiedades de Superficie
14.
Arch Microbiol ; 199(4): 597-603, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28028566

RESUMEN

A Gram-negative, aerobic, non-motile, rod-shaped bacterial strain, designated MAB-07T, was isolated from the gut of a red snow crab. The novel strain grew optimally at 20 °C, pH 7.0-8.0, and in the presence of 3% (w/v) NaCl. A phylogenetic analysis based on the 16S rRNA gene sequence indicated that the strain MAB-07T belongs to the type strains of species of the genus Lacinutrix. Strain MAB-07T exhibited 16S rRNA gene sequence similarity values of 95.5-97.8% with the type strains of species of the genus Lacinutrix. The predominant cellular fatty acids of strain MAB-07T were iso-C15:1 G (27.5%) and iso-C15:0 (21.7%). The major respiratory quinine was identified as MK-6. The polar lipids consisted of phosphatidylethanolamine, four unidentified aminolipids, and two unidentified lipids. The genomic DNA G + C content was determined to be 33.3%, and its DNA-DNA relatedness values with the type strains of L. venerupis, L. mariniflava, L. jangbogonensis, L. algicola, and Olleya aquimaris were 28-32%. Based on the data from this polyphasic taxonomic study, strain MAB-07T is considered to represent a novel species of the genus Lacinutrix, for which the name L. chionocetis sp. nov. is proposed. The type strain is MAB-07T (=KCTC 42767T = JCM 30988T).


Asunto(s)
Braquiuros/microbiología , Flavobacteriaceae/clasificación , Animales , Composición de Base , ADN Bacteriano/química , Ácidos Grasos/análisis , Flavobacteriaceae/química , Flavobacteriaceae/aislamiento & purificación , Tracto Gastrointestinal/microbiología , Filogenia , ARN Ribosómico 16S/genética , Vitamina K 2/análogos & derivados , Vitamina K 2/análisis
15.
Biomarkers ; 21(3): 243-8, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26846433

RESUMEN

Alcohol use disorders (AUD) are defined as alcohol abuse and alcohol dependence, which create a substantial public health problem worldwide. To date, no therapeutic can effectively solve these problems. They are complex diseases characterized by both genetic and environmental factors. DNA methylation can act as a downstream effector of environmental signals and account for multi-factorial nature of the disease. Global DNA methylation of peripheral blood cells has recently been proposed as a potential biomarker for disease risk. Alu elements host one-quarter of CpG dinucelotides in the genome to function as proxies for global DNA methylation. In this study, we evaluated the Alu methylation in the peripheral blood DNA of healthy volunteers and AUD patients using the pyrosequencing technology. The Alu methylation level is significantly higher in AUD compared to healthy controls (23.4 ± 1.6 versus 22.1 ± 1.0, t = 7.83, p < 0.0001). Moreover, significant correlation was found between Alu methylation and alcohol use disorders identification test score (r = 0.250, p < 0.0001), alcohol problem (r = 0.294, p < 0.0001), and life position (r = -0.205, p = 0.0005). Overall, these novel findings indicate that alcohol-related increase in Alu methylation might play a complex role in the etiology and pathogenesis of AUD. Further studies are required to elucidate the mechanisms underlying this relationship.


Asunto(s)
Consumo de Bebidas Alcohólicas/efectos adversos , Elementos Alu/genética , Biomarcadores/sangre , Metilación de ADN/genética , ADN/sangre , Adulto , Anciano , Consumo de Bebidas Alcohólicas/sangre , Alcoholes/efectos adversos , Islas de CpG/genética , ADN/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad
16.
Sensors (Basel) ; 16(2): 203, 2016 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-26861331

RESUMEN

Precise time-of-arrival (TOA) estimation is one of the most important techniques in RF-based positioning systems that use wireless sensor networks (WSNs). Because the accuracy of TOA estimation is proportional to the RF signal bandwidth, using broad bandwidth is the most fundamental approach for achieving higher accuracy. Hence, ultra-wide-band (UWB) systems with a bandwidth of 500 MHz are commonly used. However, wireless systems with broad bandwidth suffer from the disadvantages of high complexity and high power consumption. Therefore, it is difficult to employ such systems in various WSN applications. In this paper, we present a precise time-of-arrival (TOA) estimation algorithm using an IEEE 802.15.4 ZigBee system with a narrow bandwidth of 2 MHz. In order to overcome the lack of bandwidth, the proposed algorithm estimates the fractional TOA within the sampling interval. Simulation results show that the proposed TOA estimation algorithm provides an accuracy of 0.5 m at a signal-to-noise ratio (SNR) of 8 dB and achieves an SNR gain of 5 dB as compared with the existing algorithm. In addition, experimental results indicate that the proposed algorithm provides accurate TOA estimation in a real indoor environment.

17.
Sensors (Basel) ; 16(1)2015 Dec 25.
Artículo en Inglés | MEDLINE | ID: mdl-26712761

RESUMEN

In the detection of moving objects from vision sources one usually assumes that the scene has been captured by stationary cameras. In case of backing up a vehicle, however, the camera mounted on the vehicle moves according to the vehicle's movement, resulting in ego-motions on the background. This results in mixed motion in the scene, and makes it difficult to distinguish between the target objects and background motions. Without further treatments on the mixed motion, traditional fixed-viewpoint object detection methods will lead to many false-positive detection results. In this paper, we suggest a procedure to be used with the traditional moving object detection methods relaxing the stationary cameras restriction, by introducing additional steps before and after the detection. We also decribe the implementation as a FPGA platform along with the algorithm. The target application of this suggestion is use with a road vehicle's rear-view camera systems.

18.
Biomarkers ; 20(2): 136-42, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25585924

RESUMEN

Promoter hypermethylation of the O(6)-methylguanine-DNA methyltransferase (MGMT) DNA repair gene is important during carcinogenesis. We explored whether organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), were associated with hypermethylation of the MGMT gene promoter in peripheral leukocytes among 368 Koreans without cancer. Hypermethylation decreased as OCPs increased (Ptrend = 0.02), while PCB concentrations showed an inverted U-shaped association (Pquadratic < 0.01). The prevalence of MGMT promoter hypermethylation was highest within the 2nd quintile of the PCB summary score (28.4%), while it was only 2.7% in the upper 10% score. Chronic exposure to these chemicals may affect methylation of the MGMT promoter, with possibly non-monotonic dose response relationships.


Asunto(s)
Metilación de ADN , Hidrocarburos Clorados/sangre , Plaguicidas/sangre , Bifenilos Policlorados/sangre , Estudios de Casos y Controles , Contaminantes Ambientales/sangre , Cromatografía de Gases y Espectrometría de Masas , Humanos , Modelos Logísticos , Persona de Mediana Edad , O(6)-Metilguanina-ADN Metiltransferasa/genética , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas/genética , Encuestas y Cuestionarios
19.
Sensors (Basel) ; 14(9): 17516-29, 2014 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-25237900

RESUMEN

Research on real-time health systems have received great attention during recent years and the needs of high-quality personal multichannel medical signal compression for personal medical product applications are increasing. The international MPEG-4 audio lossless coding (ALS) standard supports a joint channel-coding scheme for improving compression performance of multichannel signals and it is very efficient compression method for multi-channel biosignals. However, the computational complexity of such a multichannel coding scheme is significantly greater than that of other lossless audio encoders. In this paper, we present a multichannel hardware encoder based on a low-complexity joint-coding technique and shared multiplier scheme for portable devices. A joint-coding decision method and a reference channel selection scheme are modified for a low-complexity joint coder. The proposed joint coding decision method determines the optimized joint-coding operation based on the relationship between the cross correlation of residual signals and the compression ratio. The reference channel selection is designed to select a channel for the entropy coding of the joint coding. The hardware encoder operates at a 40 MHz clock frequency and supports two-channel parallel encoding for the multichannel monitoring system. Experimental results show that the compression ratio increases by 0.06%, whereas the computational complexity decreases by 20.72% compared to the MPEG-4 ALS reference software encoder. In addition, the compression ratio increases by about 11.92%, compared to the single channel based bio-signal lossless data compressor.


Asunto(s)
Técnicas Biosensibles , Procesamiento de Señales Asistido por Computador , Programas Informáticos , Bases de Datos Factuales , Entropía , Equipos y Suministros , Humanos
20.
Sensors (Basel) ; 13(5): 6775-92, 2013 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-23698271

RESUMEN

A single-chip sensor system-on-a-chip (SoC) that implements radio for 2.4 GHz, complete digital baseband physical layer (PHY), 10-bit sigma-delta analog-to-digital converter and dedicated sensor calibration hardware for industrial sensing systems has been proposed and integrated in a 0.18-µm CMOS technology. The transceiver's building block includes a low-noise amplifier, mixer, channel filter, receiver signal-strength indicator, frequency synthesizer, voltage-controlled oscillator, and power amplifier. In addition, the digital building block consists of offset quadrature phase-shift keying (OQPSK) modulation, demodulation, carrier frequency offset compensation, auto-gain control, digital MAC function, sensor calibration hardware and embedded 8-bit microcontroller. The digital MAC function supports cyclic redundancy check (CRC), inter-symbol timing check, MAC frame control, and automatic retransmission. The embedded sensor signal processing block consists of calibration coefficient calculator, sensing data calibration mapper and sigma-delta analog-to-digital converter with digital decimation filter. The sensitivity of the overall receiver and the error vector magnitude (EVM) of the overall transmitter are -99 dBm and 18.14%, respectively. The proposed calibration scheme has a reduction of errors by about 45.4% compared with the improved progressive polynomial calibration (PPC) method and the maximum current consumption of the SoC is 16 mA.

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