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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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We propose a new solution to parallel concatenation of trellis codes with multilevel amplitude/phase modulations and a suitable iterative decoding structure. Examples are given for throughputs 2 bits/sec/Hz with 8PSK and 16QAM signal constellations.
All satellites have one common requirement, known as the command facility. This is usually a real-time direct RF link from a ground transmitter through the satellite receiver and decoder to a relay or controlled circuit. The more sophisticated research and operational satellites require a command facility which will permit storing of commands to activate systems at predetermined future times when the satellite is beyond the range of the command ground station. These satellites require an accurate clock and a source of precision frequencies. In the Nimbus spacecraft, all these functions are performed by an integrated command and clock subsystem, which includes the command clock and clock-receiver modules in the spacecraft, plus the associated command ground station. This paper will describe the functions and features of these various equipment's.
Saturn switch selector - breadboard containing logic circuitry, magnetic core input register, steady state register, and three representative decode and output channels
Surveyor lunar spacecraft telecommunications system describing RF subsystem, command decoder and signal processing
Data compressor processor concept envisions a simplified system for telemetry communications. It is simultaneously a zero-order processor and a floating aperture, a variable aperture, and a binary integer aperture with a decoded buffet fullness counter.
One-half rate convolutional encoding with sequential decoding for deep space probe telemetry links with application to Pioneer missions
Fluidic decoder and display device has low-power requirements for temperature control of thermochromic materials. An electro-to-fluid converter translates incoming electrical signals into pneumatics signal of sufficient power to operate the fluidic logic elements.
Simulated sequential decoder program in Fortran for solar mission simulation
Core sequential decoding program for advanced solar missions
Ground station phase locked servo system for decoding pulse position modulation signals from sounding rockets
Error correcting codes decoding by solving algebraic equations over finite fields
Data processing by cross correlation techniques to decode PFM signals from IMP satellites
Hybrid cross correlation telemetry data processing system design for decoding pulse frequency modulation
Improved phase-shift-keyed detector contains an active filter circuit which uses an operational amplifier and resistor-capacitor network. The detector is used in the Saturn space vehicle and Apollo telescope mount command systems to translate an analog signal from the command receiver into digital information for the command decoder.
An ENCODE and DECODE facility, a subroutine added to a FORTRAN 4 library, allows alphanumeric data to be transfered to or from an area in memory rather than to or from external input/output devices. A buffer storage array allows the operations on the data prior to writing.
Low-rate command data link performance, serial orthogonal decoder analysis, and optimal codes and strong converse for transmission over noisy memoryless channels
Reliability behavior of information transmission between transmitter-receiver pair in network of erasure channels without decoding and recoding at nodes
Error bounds for orthogonal signals in additive white Gaussian noise channels for class of generalized decision strategies permitting variable-size list decoding