A geometrical approach to the special stable distributions
Convolution formulas for Cauchy and standard normal random variable distributions derived from geometry of circular symmetric distribution on plane
Savage, L. J.↗
SEARCH · Engineering Papers
Results for “Convolution”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Berkeley array processor
Berkeley array processor /special purpose digital computer/ for correlation, convolution, recursive filtering, matrix multipication, etc
Dere, W. Y.↗
Pressurized suits can be fabricated with adjustable dimensions
Root cords sewn within tube-like channels form a fabric convolute. Cord length adjusts to individual wearer's dimensions.
Korabowski, J. J.↗
An improved telemetry system
Transmission of parity bits together with data bits by a rate one half convolutional code of 25-bit constraint length, with sequential decoding of received signal increases quantity and accuracy of data transmitted by pulse code modulated system operating at given power level.
Lumb, D. R.↗
Coding systems study for high data rate telemetry links
Performance tests of convolutional decoder systems for high data rate telemetry links
Gilhausen, K. S.↗
Low-rate communications utilizing digital coding and modulation
All digital communications signal design using convolutional coding and PSK modulation for two-way transmission of voice and data between space shuttle and ground
Batson, B. H.↗
A test set for integration of data compression/ error correction encoding techniques. II - Error correction encoding considerations
Error correction coding/decoding techniques integration, discussing convolutional and block coding and Viterbi, Sequential and Threshold decoding algorithms
Cain, J. B.↗
Bootstrap hybrid decoding for symmetrical binary input channels
Hybrid decoding technique for symmetrical binary input channels, using bootstrap algorithm across convolutionally encoded information streams
Cocke, J.↗
Smoothness of solutions of Volterra integral equations with weakly singular kernels
Differentiability of nonlinear Volterra integral equations of second kind with convolutional weakly singular kernels
Feldstein, A.↗
A parametric study of the complexity of sequential decoders, volume 2
Plots are presented of complexity versus required signal energy per bit/single-sided noise spectral density to obtain an output probability of error per bit of 0.0001 for an ideal coherent PSK demodulation. Transfer function of convolutional codes and techniques of branch and reference phase synchronization are considered.
Huth, G. K.↗
Communications terminal breadboard
A baseline design is presented of a digital communications link between an advanced manned spacecraft (AMS) and an earth terminal via an Intelsat 4 type communications satellite used as a geosynchronous orbiting relay station. The fabrication, integration, and testing of terminal elements at each end of the link are discussed. In the baseline link design, the information carrying capacity of the link was estimated for both the forward direction (earth terminal to AMS) and the return direction, based upon orbital geometry, relay satellite characteristics, terminal characteristics, and the improvement that can be achieved by the use of convolutional coding/Viterbi decoding techniques.
Source record↗
Radio astronomy Explorer B antenna aspect processor
The antenna aspect system used on the Radio Astronomy Explorer B spacecraft is described. This system consists of two facsimile cameras, a data encoder, and a data processor. Emphasis is placed on the discussion of the data processor, which contains a data compressor and a source encoder. With this compression scheme a compression ratio of 8 is achieved on a typical line of camera data. These compressed data are then convolutionally encoded.
Miller, W. H.↗
A flexible high-speed sequential decoder for deep space channels.
This paper describes a sequential decoding machine built at the Jet Propulsion Laboratory (JPL), which uses a 3-bit quantization of the code symbols and achieves a computation rate of MHz. This machine is flexible and can be programmed to decode any complementary convolutional code with rates down to 1/4 and constraint lengths up to 32. In addition, metric programmability is provided for optimization of decoder performance with respect to channel parameter variations.
Layland, J. W.↗
Viterbi decoding for satellite and space communication.
Convolutional coding and Viterbi decoding, along with binary phase-shift keyed modulation, is presented as an efficient system for reliable communication on power limited satellite and space channels. Performance results, obtained theoretically and through computer simulation, are given for optimum short constraint length codes for a range of code constraint lengths and code rates. System efficiency is compared for hard receiver quantization and 4 and 8 level soft quantization. The effects on performance of varying of certain parameters relevant to decoder complexity and cost are examined. Quantitative performance degradation due to imperfect carrier phase coherence is evaluated and compared to that of an uncoded system. As an example of decoder performance versus complexity, a recently implemented 2-Mbit/sec constraint length 7 Viterbi decoder is discussed. Finally a comparison is made between Viterbi and sequential decoding in terms of suitability to various system requirements.
Heller, J. A.↗
High data rate coding for the space station telemetry links.
Coding systems for high data rates were examined from the standpoint of potential application in space-station telemetry links. Approaches considered included convolutional codes with sequential, Viterbi, and cascaded-Viterbi decoding. It was concluded that a high-speed (40 Mbps) sequential decoding system best satisfies the requirements for the assumed growth potential and specified constraints. Trade-off studies leading to this conclusion are viewed, and some sequential (Fano) algorithm improvements are discussed, together with real-time simulation results.
Lumb, D. R.↗
Performance results for a hybrid coding system.
Results of computer simulation studies of the hybrid pull-up bootstrap decoding algorithm, using a constraint length 24, nonsystematic, rate 1/2 convolutional code for the symmetric channel with both binary and eight-level quantized outputs. Computational performance was used to measure the effect of several decoder parameters and determine practical operating constraints. Results reveal that the track length may be reduced to 500 information bits with small degradation in performance. The optimum number of tracks per block was found to be in the range from 7 to 11. An effective technique was devised to efficiently allocate computational effort and identify reliably decoded data sections. Long simulations indicate that a practical bootstrap decoding configuration has a computational performance about 1.0 dB better than sequential decoding and an output bit error rate about .0000025 near the R sub comp point.
Hoffman, L. B.↗
The JPL Data Decoder Assembly for mission independent sequential decoding.
Implementation of the Fano sequential decoding algorithm as one of the functions of the Data Decoder Assembly. Installation of these systems at all stations in the Deep Space tracking network has been completed, and the systems will be used to support future deep space missions which will be using long constraint length convolutional codes at medium rates (less than 2048 bits/sec). The design philosophy and the performance of the sequential decoder are discussed.
Grauling, C. R.↗
Linear response to nonstationary random excitation.
Development of a method for computing the mean-square response of linear systems to nonstationary random excitation of the form given by y(t) = f(t) x(t), in which x(t) = a stationary process and f(t) is deterministic. The method is suitable for application to multidegree-of-freedom systems when the mean-square response at a point due to excitation applied at another point is desired. Both the stationary process, x(t), and the modulating function, f(t), may be arbitrary. The method utilizes a fundamental component of transient response dependent only on x(t) and the system, and independent of f(t) to synthesize the total response. The role played by this component is analogous to that played by the Green's function or impulse response function in the convolution integral.
Hasselman, T.↗