Showing papers on "Pulse-position modulation published in 1978"
Book•
01 Jan 1978
TL;DR: This book introduces the field of Frequency Modulation, and discusses its applications in telecommunications, as well as some of the techniques used in coding and amplitude modulation.
Abstract: 1 Introductory Topics 2 Amplitude Modulation: Transmission 3 Amplitude Modulation: Reception 4 Single-Sideband Communications 5 Frequency Modulation: Transmission 6 Frequency Modulation: Reception 7 Communications Techniques 8 Digital Communications: Coding Techniques 9 Wired Digital Communications 10 Wireless Digital Communications 11 Network Communications 12 Transmission Lines 13 Wave Propagation 14 Antennas 15 Waveguides and Radar
77 citations
TL;DR: Pulse interval and width modulation (PIM) as discussed by the authors is a pulse analog modulation system suitable for light emitting diodes that is characterized by the following compared with Pulse Interval Modulation: Pulse repetition frequency is reduced by one half.
Abstract: This paper proposes new pulse analog modulation system; Pulse Interval and Width Modulation suitable for light emitting diodes. In this system pulses have information on both their width and interval between them. Pulse Interval and Width Modulation is characterized by the following compared with Pulse Interval Modulation. First: Pulse repetition frequency is reduced by one half. Second: Duty ratio is 50 % on the average. Third: More power is needed while carrier to noise ratio could be improved instead. The paper shows how it works and comparison with another pulse analog modulation such as Pulse Frequency Modulation or Pulse Interval Modulation. The paper also shows an experiment of twin channel transmission employing two light emitting diodes, two optical fiber transmission lines and two PIN photodiodes as an example of application of Pulse Interval and Width Modulation.
57 citations
TL;DR: It is shown that, in the channelized common carrier bands below 15 GHz, the first two (complex) terms of the power series are usually sufficient for characterizing multipath effects.
Abstract: The frequency transfer function of a multipath fading channel is examined in terms of its effects on digital radio signals. The transfer function is expanded into a power series about the channel center frequency and the coefficients are related to the multipath structure. It is then shown that, in the channelized common carrier bands below 15 GHz, the first two (complex) terms of the power series are usually sufficient for characterizing multipath effects. This demonstration is based on a mean-square error-of-fit measure which is applied to the multipath fading response and evaluated under some worst-case assumptions.
26 citations
TL;DR: A two-bit instantaneously adaptive delta modulator intended for application as the input stage of a code converter is presented and its step adaptation algorithm is derived from that used in high information delta modulation (HIDM).
Abstract: A two-bit instantaneously adaptive delta modulator intended for application as the input stage of a code converter is presented. Its step adaptation algorithm is derived from that used in high information delta modulation (HIDM). The improvement in performance relative to the HIDM system is gained by its ability to reduce overshoots and respond faster to signal variations. A hardware model that allows the comparison between these delta modulators is described and results of measurements on narrow-band noise and sinewave input signals are presented. Two possible structures to generate p.c.m. signals by code conversion are described and computer simulation results presented for one of them.
7 citations
TL;DR: In this paper, the inter/cross modulation levels occurring in signals from stripe-geometry (GaAl) were investigated by computer simulation for the case of time-division multiplexed (TDM) pulse-analog modulation (PAM).
Abstract: Inter/cross modulation levels occurring in signals from stripe-geometry (GaAl)As double-heterostructure diode lasers are investigated by computer simulation for the case of time-division multiplexed (TDM) pulse-analog modulation (PAM). It is shown that pulse-position modulation (PPM) is the preferred modulation scheme for high pulse rates, and inter/cross modulation levels are evaluated for the format TDM-PPM. It is shown that the inter/cross modulation level is greatly improved when diode lasers are biased above threshold. Based on this evaluation, it is concluded that effectively inter/cross modulation-free optical transmission at a pulse rate up to 108 \times 10^{6} pulses per second by TDM-PPM is feasible. This limiting rate permits the transmission of 12 color TV channels or 10800 telephony channels.
5 citations
TL;DR: A combined pulse-amplitude/pulse-position modulation tachnique is proposed for digital optical communication systems and evaluations of its behaviour in terms of coding efficiency, spectral density, timing information content, and error probability are summarised.
Abstract: A combined pulse-amplitude/pulse-position modulation tachnique is proposed for digital optical communication systems. Evaluations of its behaviour in terms of coding efficiency, spectral density, timing information content, and error probability are summarised. Alternative receiving schemes are devised to improve system performance.
4 citations
TL;DR: The theory for design of a rate multiplier or a binary adder frequency synthesizer for a specified level of noise attenuation is developed and the phase jitter associated with each pulse is characterized and illustrated in the time domain.
Abstract: The theory for design of a rate multiplier or a binary adder frequency synthesizer for a specified level of noise attenuation is developed. Examples are presented to demonstrate the design procedure and the pattern of the pulse train output. The phase jitter associated with each pulse is characterized and illustrated in the time domain. The maximum absolute phase deviation is used as a measure of the phase modulation amplitude of the pulse train. Computer simulation resulted in simple equations approximating the amplitude of worst case spectral components.
3 citations
01 Nov 1978
TL;DR: In this paper, the authors examined the performance of tree-searching decoding of an optical beam with both photodector gain effects and receiver thermal noise, and derived the relation between tree search and decoding.
Abstract: Optical pulsing of a laser beam provides a convenient manner for transmitting digital information, and such procedures have led to well-accepted classes of pulse amplitude and pulse position modulation formats. However the excessive pulse dispersion and background light bursts that characterize several optical channels severly limit performance and achievable data rates. One procedure for combating these effects is to encode data over a multiple of pulse frames, and decode sequences of pulses rather than each pulse individually. In the paper pulse to pulse encoding and decoding of an optical beam is examined, considering both photodector gain effects and receiver thermal noise. Theoretical performance results are presented, and the relation between this type of decoding and “tree searching” is developed.
TL;DR: In this article, error performance in optical communication with differential pulse-position modulated optical carrier is discussed. And both threshold type and maximum value type of decision schemes are also considered, including the effects of several parameters, such as the number of time slots, the duty ratio, the extinction ratio, count dimension, the signal-to-background radiation power ratio, and the signal tothermal noise power ratio.
Abstract: Error performance in optical communication, where the information is transmitted by means of the differential pulse-position modulated optical carrier, is discussed. Additive independent background radiation and thermal noise are taken into account. Both threshold type and maximum value type of decision schemes are also considered. The effects of several parameters, such as the number of time slots, the duty ratio, the extinction ratio, the count dimension, the signal-to-background radiation power ratio, and the signal-to-thermal noise power ratio are discussed in detail. The detection characteristic of this system are made clear by comparison with a pulse-position modulation system.