Documentation of digital image information--video or laser imager?

A conventional differential line (DL), commonly used on typical digital circuit boards for transmitting high-speed digital data, has fundamental limitations on the maximum signal bandwidth (~10 GHz), mainly due to signal skew, multiple line coupling, and EM interference. Therefore, to support super-high-speed digital data transmission, especially for beyond 5G communications, a practical high-performance transmission structure for digital signals is required. Balanced lines (BLs) can transmit the differential signals with multiple advantages of ultra-wide bandwidth, common-mode rejection, reduced crosstalk, phase recovery, and skew reduction, which enable super-high-speed transmission. In order to utilize the BLs in the DL-based digital circuit, connecting structures between a DL and BLs are required, but the DL-to-BL transition structures dominate the operating bandwidth and signal properties. Therefore, in this paper, properties, and design methods for two ultra-wideband DL-to-BL transitions, i.e., DL-to-CPS (coplanar stripline) and DL-to-PSL (parallel stripline) transitions, are presented. Both implemented DL-to-CPS and DL-to-PSL transitions provide high-quality performance up to 40 GHz or higher, significantly enhancing the frequency bandwidth for the transmission of digital signals while providing compatibility with the DL-based PCBs. The fabricated DL-to-CPS transition performs well from DC to 40 GHz with an insertion loss of less than 0.86 dB and a return loss of more than 10 dB, and the fabricated DL-to-PSL transition also provides good performance from DC to 40 GHz, with an insertion loss of less than 1.34 dB and a return loss of more than 10 dB. Therefore, the proposed DL-to-BL transitions can be applied to achieve super-high-speed digital data transmission with over 40 GHz bandwidth, which is more than four times the bandwidth of the DL, supporting over 200 Gbps of digital data transmission on PCBs for the next generation of advanced communications.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation William E. Glenn, Henry Helmken; Satellite distribution of digital compressed video audio and data. AIP Conf. Proc. 25 January 1995; 325 (1): 83–89. https://doi.org/10.1063/1.47256 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

5 - How is data transmitted?

The deployment of federated learning in a wireless network, called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">federated edge learning</i> (FEEL), exploits low-latency access to distributed mobile data to efficiently train an AI model while preserving data privacy. In this work, we study the spatial (i.e., spatially averaged) learning performance of FEEL deployed in a large-scale cellular network with spatially random distributed devices. Both the schemes of digital and analog transmission are considered, providing support of error-free uploading and over-the-air aggregation of local model updates by devices. The derived spatial convergence rate for digital transmission is found to be constrained by a limited number of active devices regardless of device density and converges to the ground-true rate exponentially fast as the number grows. The population of active devices depends on network parameters such as processing gain and signal-to-interference threshold for decoding. On the other hand, the limit does not exist for uncoded analog transmission. In this case, the spatial convergence rate is slowed down due to the direct exposure of signals to the perturbation of inter-cell interference. Nevertheless, the effect diminishes when devices are dense as interference is averaged out by aggressive over-the-air aggregation. In terms of learning latency (in second), analog transmission is preferred to the digital scheme as the former dramatically reduces multi-access latency by enabling simultaneous access.

ASGE Technology Status Evaluation Report: wireless esophageal pH monitoring system

지상파 TV의 디지털 전환이 완료되었지만 지상파 라디오는 전송방식을 결정하지 못해 아날로그 방송을 유지하며 표류하고 있는 상태이다. 본 연구에서는 지상파 방송사의 종사자를 대상으로 상호지향성 모델을 토대로 디지털 라디오 전송방식을 결정하는 중요 요인에 대한 인식차이를 살펴보고 쟁점 요인을 도출하였다. 연구결과, 지상파 방송 3사는 디지털 라디오가 점유할 주파수 대역 선택에서 가장 큰 인식의 차이가 있으며 제작과 송출의 병행 여부, 주파수 이용 효율성, 방송 품질과 서비스 정도는 서로 의견의 차이가 없는 것으로 나타났다. 그리고 디지털 라디오 방송의 전환에 있어 가장 큰 쟁점 요인은 FM 라디오방송이 사용하는 주파수대역(88-108 MHz)과 지상파 DMB방송 주파수대역(VHF Ch7~13), FM 라디오방송 인접대역(76~88MHz: VHF Ch5~6) 중 어떤 주파수 대역을 디지털 라디오용으로 선택하는지의 문제, 즉 DAB+, HD-Radio, DRM+ 가운데 특정 전송방식을 선택하는 문제로 귀결되었다. 이에 본 연구에서는 제작 송출 병행이 가능하고 송 중계소 1-2개로 송신 효율을 높일 수 있고 신규 사업자 진입이 가능한 방식을 채택함으로써 라디오방송서비스의 품질과 이용자의 만족도를 높일 것을 제안하고자 한다. Though the digital transition of terrestrial TV has been completed, the transmission system for terrestrial radio has not been determined and terrestrial radio still keeps its analog transmission. This study, under coorientation model, aims to explore the cognitive difference in recognizing important factors to be considered in deciding the digital radio transmission system between the employees of terrestrial broadcasters and then crucial issues related to the factors are driven. It has been found that the most big cognitive difference among the employees of three major terrestrial broadcasters lies in selecting frequency band for digital radio transmission. But there was little difference of opinion on simultaneous production-transmission, efficiency of frequency usage, broadcast quality and standards of service. The most disputable point in transition to digital radio broadcasting is selecting the frequency band for digital radio between the frequency bands used for FM radio broadcast (88-108MHz), terrestrial DMB (VHF Ch7~13) and FM radio adjacent broadcast band (76~88MHz: VHF Ch5~6). So, the question concludes into the selection issue between DAB+, HD-Radio, and DRM+. To improve the quality of radio broadcasting service and enhance the satisfaction of listeners, it is desirable to allow to operate both production system and transmission station, to enhance high transmission efficiency with minimum transmission facility, and to permit new entrance of broadcasters.

IEEE 802.22 is the cognitive radio-based first worldwide standard for wireless regional area network (WRAN). The primary objective of this standard is to provide broadband access to remote and rural areas. In these remote areas, a large number of vacant TV channels are available, known as white spaces. This standard allows broadband access to the users using these TV white spaces (TVWS). Also, much analog transmission has been moved towards digital transmission in UHF band so this situation has created a digital divide. In this paper, we proposed a novel scheme of simulation for the physical layer of IEEE 802.22 Wireless Regional Area Network (WRAN) with another cyclic prefix. In this paper, we have also demonstrated the effect of length of cyclic prefix in OFDM symbol on the BER performance of the physical layer of WRAN. We simulated the physical layer of WRAN with cyclic prefix 1/4 and 1/32 between successive OFDM symbols. We used convolution code with code rate 1/2 as FEC and evaluated the performance with BPSK, QPSK, and QAM-19 digital modulation schemes in Rayleigh fading condition in MATLAB. We concluded that the effect of ISI can be mitigated with cyclic prefix 1/32 for all three proposed modulation schemes and found that better BER performance in limited SNR. Also, the performance of BPSK with CP 1/32 is superior to QPSK and QAM-16 for CP of 1/4 as well as 1/32.

This paper describes an integrated circuit chip set* designed for low-cost transmission of analog and digital data. The system provides remote motion control capability and is designed for home computer or microprocessor control applications. The control system is based on a multichannel serial bus concept and uses pulse-position modulation (PPM) for information transfer. The input and output of the system interface directly with a home or personal computer.

The basic pressure housings used in all units are 24-in. OD aluminum hemisphere sets with a 1-in. wall thickness and 16,400-ft designed operating -depth. These sets are used in several different combinations and configurations as a basis for both seismic and oceanographic instrumentation capsules. Units using four-, two- and one-sphere combinations have been deployed successfully. The instrumentation includes digital data recording and an acoustical control and digital data transmission system. The free-standing ocean floor capsule has been adapted to many uses and configurations and has proved to be extremely versatile and reliable. The basic technology of these systems is developed and only waits to be employed to replace more expensive and less satisfactory methods. INTRODUCTION Increased scientific interest in phenomena occurring below the surface of the ocean has prompted expansion of the deep-sea instrument capsule program at the Institute of Geophysics and Planetary Physics, U. of California, San Diego. The basic building block of all systems is the 24-in. OD, 1-in. wall thickness aluminum pressure hemisphere rated for a 16,400-ft operating depth. These are installed in pairs with an O-ring on each side of a center plate. Center plates of one-, two- and three-coplanar instrument mounting holes have been constructed and tested as illustrated in Figs. 1 through 3. Instrumentation is typically mounted from swinging brackets split at the line of the center plate to allow access to both interior and exterior components. In multiple-sphere systems interconnecting electrical wiring is routed through small holes drilled in the center plate between instrument mounting holes. This system eliminates the need for underwater electrical connectors between housings, thus eliminating several typically more troublesome components. Any underwater electrical connectors that are employed are placed in triangular cut-outs between spheres as in Fig. 4. This affords maximum protection from accidental bumping or snagging of a connector during handling. The basic hemispherical package is used in several different combinations and configurations as a basis for both undersea seismic and oceanographic applications. THE FOUR-SPHERE CAPSULE Fig. 5 illustrates the most complex of the capsules which uses four hemisphere sets, three with coplanar instrument mounting plate and one above for an extra flotation and stability in the water. These house a long period Block-Moore vertical seismometer, a two-axis tiltmeter, a low power digital data-recording system, and a 10-channel underwater acoustic command system that includes a digital data transmission link. The data link sends 24 separate' channels of data to the surface at 100 bits/sec for storage in a decoding and memory unit. Results can be displayed individually by channel or printed out serially on a printer. The present system has a very low bit-error rate as long as position is maintained within 300 directly over the capsule.

Due to the harsh working environment, casualties, and severe shortage of skilled operators associated with crawler cranes, a remote control system was developed. First, based on the five-dimensional digital twin model, the overall architecture of a digital twin state monitoring system for crawler cranes was proposed, and a digital twin platform was established. Secondly, various sensors were installed on the crawler cranes to obtain their real-time motion parameters. Then, a highly low-latency control system was developed based on the CAN bus and 5G, enabling intelligent assisted manipulation and remote control of the crawler cranes. Finally, the crawler crane's operating status and key parameters were monitored using the digital twin and real-time data transmission. Finally, the digital twin model and real-time data transmission were used to monitor the operating status and key parameters of the crawler crane, and the data was fed back to the status monitoring system. Response delay tests and hook control accuracy tests were also conducted to verify the real-time and reliability of the crawler crane status remote control system.

Distributed feedback (DFB) lasers are used extensively as optical sources within fiber optic telecommunications systems. These semiconductor lasers are valued for their single optical mode operation which enables their use in high bit rate digital and broadband analog transmission systems. We discuss requirements imposed upon DFB lasers used in such applications. We briefly review and illustrate general techniques for modeling DFB laser operation by comparison of measured and modeled device characteristics below and above lasing threshold. We focus on the phenomenon of spatial hole burning which substantially affects operation of all DFB lasers, especially those tailored to produce high fiber coupled power from a single mirror facet. We illustrate insights gained by measurement and modeling of DFB lasers using as an example the particular case of analog transmission of multichannel video signals.

Demand for mobile data transfer has driven developing technologies, including optical wireless communications, such as visible light communication (VLC). The high demand has contributed much higher power consumption, which means an increase in carbon emission as well. VLC is an alternative solution for green communication because of its potential applications for both lighting and data transfer simultaneously. In this paper, we study a low-cost VLC system, which consists of two sides, to understanding its performance for digital data transmission. The first part of the transmitting end consists of a microcontroller and an LED. The second part of the receiving end consists of a photodiode and a microcontroller. This research considers OOK modulation, a darkroom to avoid noise from other light sources, and three variables of wavelength spectrums, clock rates, and distances. Parameter observation of bit-error-rate or BER shows that the average BER of LED in white color has smaller BER than red, green, and blue LED, which 0.377, 0.412, 0.387, and 0.387, respectively. From this research, we obtain an insight into sufficient received power and component characteristics that are necessary for developing effectively VLC systems.

A Ka-band GaInP/GaAs HBT double balanced upconvert mixer has been designed and fabricated. This circuit is to be used in a multifunction T/R module for local multipoint distribution systems (LMDS) which include both analog and digital transmission. A conversion gain of 1 dB, and an output power of -10 dBm from 27 GHz to 30 GHz for an LO input power of 10 dBm at 26 GHz were measured. The LO isolation to the output was measured to be 20 dB. These results are the best reported at Ka-band for a mixer using transistors from digital HBT library.

The move from analogue to digital HF broadcasting using the Digital Radio Mondiale (DRM) standard poses some problems of transition that have not been present for the transition of other digital broadcasting systems most notably that there is little or no additional spectrum available to support the simulcast period when both analogue and digital transmissions will coexist. This paper explores the possibilities of using the in-built capabilities of the DRM standard to offer a propagation based solution to the lack of spectrum.

A 3-way Laser Driver ASIC has been implemented in deep-submicron CMOS technology, according to the CMS Tracker performance and rad-tolerance requirements. While being optimised for analogue operation, the full-custom IC is also compatible with LVDS digital signalling. It will be deployed for analogue and digital transmission in the 50.000 fibre link of the Tracker. A combination of linearization methods allows achieving good analogue performance (8-bit equivalent dynamic range, with 250 MHz bandwidth), while maintaining wide input common-mode range (±350 mV) and power dissipation of 10 mW/channel. The linearly amplified signals are superposed to a DC-current, programmable over a wide range (0-55 mA). The latter capability allows tracking of changes in laser threshold due to ageing or radiation damage. The driver gain and laser bias-current are programmable via a SEU-robust serial interface. The results of ASIC qualification are discussed in the paper.