Tuner and demodulator performance for cable distributed D2-MAC TV-signals

ICITAL transmission systems of all types are of great current interest as we embark on the information age. For any new transmission system, the topology, components, and system parameters are determined by many and various techniques. They are chosen not only by explicit, deductive technical reasoning, but also by the art of engineering, the desire for continued product line compatibility, patents possessed or not possessed, and new technology. Nonetheless, most digital transmission systems are made up using one or more of the following components: a bandpass filter, low-pass filter, Nyquist filter, slope equalizer, cable equalizer, and transversal equalizer. These items are the subject of this article. It is ironic that digital transmission systems have a preponderance of such components-all necessary for analog signal conditioning of the digitally transmitted signal. In the myriad of digital transmission systems, two distinct approaches to filtering and equalization predominate: one for baseband systems and the other for frequency translated, or modulated, signal systems. This division results from the need to have a competitive system transmission efficiency to cost ratio: where transmission efficiency is transmitted bit rate/channel bandwidth (BR/BW). For baseband systems, as might be expected, the difficulties, and thus cost, of filtering and equalization increase with increased transmission efficiency. To obtain a favorable BR/BW to cost ratio, the bandwidth, an available quantity, is usually sacrificed to keep system costs low. Signal modulation is required when it is desired to simultaneously transmit several baseband signals over common transmission facilities using a frequency division multiplex scheme. A modulated signal system is also necessary when the transmission vehicle has a significant low-frequency limitation; as does, for example, the general customer premises-to-customer premises telephone connection. In such systems, costs start off high because of the additional modulation circuitry. Money can then be further spent on filtering and equalization to allow for increased transmitted bit rate in order to provide a more reasonable BR/BW to cost ratio. Based upon the above premise, the text expands further on the differences between filters and equalizers used for baseband and modulated digital transmission systems.

In digital transmission through a metallic subscriber line, burst bit errors are produced due to impulsive noise and other causes. It is important to investigate the actual properties of those bit errors. This paper presents the result of long‐term measurements using various kinds of cores concerning the bit error gap length in the time‐compression multiplex directional control transmission system. It is shown that the bit error rate can be characterized by three gap length ranges. A model is proposed which can represent accurately the features of those distribution patterns of gap length through a simple formulation. The model is compared with the actual characteristics, and the usefulness of the model is demonstrated. As an application of the model, several evaluation measures for the transmission quality (such as bit error rate and errored seconds) are discussed, and it is shown that a more detailed quality specification than in the past (the evaluation in a short‐term observation for 100 ms, for example) can be realized, based on the estimated distribution.

A theoretical computation method for a digital TV transmitter coverage probability is proposed. The computation make use of the assumption that the studied digital TV transmitter is sharing a co-channel frequency band with six surrounding analogue TV transmitters whose arriving signals are considered as co-channel uncorrelated interferers. Coverage probability expressions have been derived considering the digital TV signal as the wanted power and the remaining analogue TV signals as co-channel interferers. After several Monte Carlo simulation-based comparisons the utilized theoretical approach has shown to be in good agreement, with a much less important computation time.

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

This paper approaches the topic of Laser Beam Image Recording from the user's perspective. It discusses the parameters of concern to a system group charged with specifying a high performance Laser Beam Image Recording Subsystem. The paper concentrates on those parameters that have significant impact on interface complexity, image quality and cost. A block diagram of a typical Laser Beam Recorder is shown along with a brief explanation of the following subsystems: Image Data Interface, Control Data Interface, Image Data Processor, Annotation, Scan Data Processor, Command and Control, Electro Optics, Film Transport, and Built-In-Test Equipment. Ranges of the following signal parameters are given: Line Rate, Data Rate, Data Duty Factor and Bytes/Line. Typical values of the following critical image quality parameters are given: Resolution, Raster and Banding, Geometric Fidelity, and Density Fidelity. Each of the critical parameters are defined and measuring techniques and equipment discussed. A list of system level questions which a user should consider when formulating the Laser Beam Recorder specification are also presented.

Orthogonally multiplexed orthogonal amplitude modulation (OMOAM) is a modulation family unifying numerous modulations date back from 1960s and also many standard-preferable modulations. By converting frequency multiplexing to time multiplexing, orthogonally time multiplexed orthogonal amplitude modulation (OTMOAM) is proposed to explore advantages over the conventional orthogonally multiplexed orthogonal amplitude modulation (OMOAM). Transmitter and receiver system models unifying both OTMOAM and OMOAM are provided, and bit error rate (BER) for both systems are also derived for flat Rayleigh fading channel. Numerical results show that OTMOAM provides lower PAPR and better BER performance in high signal-to-noise power ratio than the conventional OMOAM.

This article presents a fully differential power-tuning heterodyne on-chip sensing readout system at 240 GHz. The chip enables the measurement of not only the transmission parameter but also the reflection parameter to sense the permittivity of different materials by using four heterodyne mixer-based receiving channels connected to a dielectric sensing element. To facilitate the operation and characterization, three frequency multiplier chains are included to generate the required two identical radio frequency (RF) and one local oscillator (LO) subterahertz signals. RF frequency multiplier chain is configured to enable a tunable power level of the RF signal by using a variable attenuator. A chip prototype using 130-nm silicon–germanium (SiGe) BiCMOS is implemented with a size of 11 mm2 and dc power consumption of 2.7 W. The measured 10-dB bandwidth of 20.8% is achieved in a frequency range from 207 to 257 GHz with 14-dB measured power-tuning range. The transmission and reflection parameters’ measurements for copper and gummi show a differentiated value in terms of magnitude and phase, which demonstrates the sensing function of the proposed readout system.

This paper describes a new digital NTSC TV and audio signal transmission system in which circuit configurations are simplified and made more inexpensive than MPEG 2 on the basis of the subjective evaluation of the picture quality. An NTSC TV signal and an audio signal can easily be transmitted to the receiver at the same time, since the transmission rate is kept unchanged due to the insertion of the digital audio signal into the horizontal sync pulse of the digital NTSC TV signal. The proposed system has three features. Firstly, the system could give a satisfactory picture quality for consumer-use visual appliances even though the quality of the reproduced pictures is lower than that of the normal digital NTSC TV picture codes obtained at a sampling frequency of 4.00/spl times/fsc with a quantisation level of 8 bits. Secondly, the system can satisfactorily transmit NTSC TV picture codes at a low transmission rate of 50 Mbps even if such an advanced compression technique as MPEG 2 has not been used. Thirdly, the system is used for transmission of the digital audio signals which are inserted into the horizontal sync pulse of the digital NTSC TV signal. A combination of edge-emitting LEDs (ELEDs) and single-mode (SM) optical fibers enables the system to easily transmit a digital NTSC TV picture signal together with digital audio signals over a distance of 10 km through the SM optical fibers.

In this paper, bit error rates (BERs) of Fredece FM are analyzed theoretically. The correlative code whose transmission bandwidth is preliminary limited by Nyquist filter, is used for obtaining the Fredece FM signal. The spectrum of the Fredece FM signal is compact enough to adopt for mobile radios. However, the correlative code generally requires a multilevel decision. In the demodulation process, the received signal is frequency‐multiplied prior to the differential detection. This makes it possible to perform the binary decision. It is noted that the BER performance of Fredece FM is the same as that of the case where a multilevel differential detection is performed without frequency multiplication. Therefore the frequency multiplication is regarded as linear amplification in the frequency region. It is easy to analyze theoretically BERs with the multilevel differential detection for Rayleigh fading. Then the BERs for nonfading are derived easily by using the property where the average BER for quasi‐static Rayleigh fading is related to that for nonfading through Laplace transform. Finally, the relationship between the modulation index and the irreducible error level is studied.

Digital modulation is the technique in which the discrete changes in a message signal are imposed onto parameters (amplitude, frequency, or phase) of a sinusoidal carrier wave. This chapter summarizes the essentials of digital transmission and shows how to assess the quality of a digital transmission by revisiting the mathematical foundation for calculating the probability of error, employing the bit error rate metric, and acquiring knowledge of the eye diagram. It introduces binary shift‐keying modulation in digital transmission and describes the modulation and demodulation principles of amplitude shift keying (ASK), frequency shift keying (FSK) and phase shift keying (PSK) modulations. The chapter shows how to assess the transmission quality of ASK, FSK, and PSK. It also discusses the advantages, shortcomings, and applications of ASK, FSK, and PSK.

Barcode-assisted medication administration (BCMA) is technology with demonstrated benefit in reducing medication administration errors in hospitalized patients; however, it is not routinely used in emergency departments (EDs). EDs may benefit from BCMA, because ED medication administration is complex and error-prone. A naïve observational study was conducted at an academic medical center implementing BCMA in the ED. The rate of medication administration errors was measured before and after implementing an integrated electronic medical record (EMR) with BCMA capacity. Errors were classified as wrong drug, wrong dose, wrong route of administration, or a medication administration with no physician order. The error type, severity of error, and medications associated with errors were also quantified. A total of 1,978 medication administrations were observed (996 pre-BCMA and 982 post-BCMA). The baseline medication administration error rate was 6.3%, with wrong dose errors representing 66.7% of observed errors. BCMA was associated with a reduction in the medication administration error rate to 1.2%, a relative rate reduction of 80.7% (p < 0.0001). Wrong dose errors decreased by 90.4% (p < 0.0001), and medication administrations with no physician order decreased by 72.4% (p = 0.057). Most errors discovered were of minor severity. Antihistamine medications were associated with the highest error rate. Implementing BCMA in the ED was associated with significant reductions in the medication administration error rate and specifically wrong dose errors. The results of this study suggest a benefit of BCMA on reducing medication administration errors in the ED.

The signal levels around and within eight suburban houses were measured at 800 MHz. These measurements are needed in refining the requirements for portable-radio communication systems that can accommodate low-power radiotelephone sets. The measurements were made from an instrumentation van having an erectable 27-foot-high antenna. Large-scale distributions of the small-scale signal medians are approximately log normal. The decrease in median signal level with distance ranges from d−3 to d−6.2 for the eight houses. Signal decreases as d−4.5 for the overall data set. At 1000 feet, regressions to signal levels range from 12.5 to 37.1 dB below free-space propagation levels for locations outside and locations inside on first and second floors. In basements, regression levels at 1000 feet range from 29 to 48.2 dB below free space. For the overall data set, regression signal levels at 1000 feet are 27.7 dB below free space. For all the basements, this value is 39.6 dB. Other signal statistics are given in this paper.

In high‐speed digital transmission in mobile satellite and land mobile communications, one of the serious problems is the effect of waveform distortion due to the frequency‐selective fading. This paper considers the GMSK modulation system, which is considered as useful as the modulation scheme for digital mobile communication.The effect of the waveform distortion produced by the time‐delay spread of the scattered interfering waves in the Nakagami‐Rice fading channel is considered and the bit error rate is calculated theoretically. Numerical examples of bit error rate performance are illustrated. It is shown that the bit error rate is improved when there is an average delay time or a time‐delay spread in the scattered interfering wave, compared with the case without a delay. However, the effect is relatively small.

The objective of this study was to identify individual sources of noise and their contribution to the overall noise that influences valid measurement of otoacoustic emissions in neonates. The hypothesis was that careful selection of eliciting signals and signal processing parameters, unique analysis of measured results, and control of certain subject characteristics would allow isolation of these individual noise sources and determine their relative influence. Eliciting signal parameters were optimized and held constant to minimize equipment noise. Analysis of noise floors in relation to signal level was used to identify equipment-related noise associated with changes in signal parameters. Analysis of noise floor distributions was used to determine whether environmental noise entered the measurements via inadequate coupling of the probe to the ear. The acoustic characteristics of the middle ear were varied via subject selection to determine the influence of middle-ear characteristics on noise floor levels. The two sources of noise associated with the measurement equipment need not contribute to the noise floor for biologically relevant otoacoustic emissions measurements (eliciting signal levels between 30 and 75 dB SPL). Of the two pathways identified for environmental noise, the pathway resulting from an inadequate seal between the probe and the ear canal can be eliminated. One of the two sources of noise related to the subject, noise resulting from biologic activity unrelated to the ear can be minimized. However, the remaining factor, the status of the middle ear, has been shown to contribute as much as 6 dB to the overall noise floor. Careful selection of signal parameters and additional data analyses and procedural variables can isolate or control several sources of noise that influence distortion product otoacoustic emission measurements in neonates. Tight coupling between the probe unit and the external ear canal should be maintained for all measurements. Middle ear abnormalities can increase noise floors up to 6 dB.

Long Range Wide Area Network (LoRaWAN) provides a promising solution for long-range, low-power wireless communication in Internet of Things (IoT) applications. However, energy consumption remains a critical challenge that significantly impacts network lifetime and scalability. Traditional LoRaWAN implementations rely on automatic and continuous transmission parameter allocation schemes managed by centralized gateways, which fail to adapt to dynamic network conditions such as varying link quality, node mobility, and fluctuating energy levels, leading to excessive energy consumption and reduced network performance. In this work, we propose Adaptive Energy Efficient Routing Protocol (AEERP), a reinforcement learning-based framework that dynamically optimizes transmission parameters in LoRaWAN network. Our approach leverages Expected State-Action-Reward-State-Action (SARSA) to enable intelligent adaptation of spreading factor, transmission power, and gateway selection based on real-time conditions. Key innovations include: (1) a hybrid Q-value initialization strategy combining domain knowledge with exploration, (2) adaptive discount factor and learning rate mechanisms, and (3) joint optimization of transmission parameters based on residual energy, distance, and Packet Delivery Ratio (PDR). Extensive simulations demonstrate that AEERP significantly outperforms state-of-the-art methods, achieving substantial energy conservation, superior PDR, enhanced signal-to-noise ratios, and reduced bit error rates. Results show that AEERP effectively balances energy efficiency, and communication reliability for sustainable LoRaWAN deployments.