Digital systems are technically attractive for the delivery of high quality audio to the home because they can be substantially transparent even under conditions of impaired reception, and permit scrambling without de...
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An effective method to detect signalling tones between switching centers on P. C. M. channels is presented in this paper;signalling techniques are in accordance to C. C. I. T. T. Rec 5-Bis. Instantaneous power estimat...
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ISBN:
(纸本)0444876952
An effective method to detect signalling tones between switching centers on P. C. M. channels is presented in this paper;signalling techniques are in accordance to C. C. I. T. T. Rec 5-Bis. Instantaneous power estimation of each tone is FFT techniques based which profit from equal tone spacing and free interference points in the spectrum in order to make an optimal estimation. In addition, the impact of finite operating arithmetics machine is shown;in order to perform it, specific software tools for this simulation which include truncation and rounding, when implementing the method on finite precision machine, are used. The presented system allows the simultaneous detection of all the 2. 048 Mbits/s link channels using only 40 signal samples per channel. The achieved level for cost, consumption and volume is competitive with other alternative approaches.
The development of a ballistic missile or satellite launcher requires a great number of varied measurements distributed right over the missile. The PCM CANNES system is basically featured by its decentralized structur...
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ISBN:
(纸本)0876648936
The development of a ballistic missile or satellite launcher requires a great number of varied measurements distributed right over the missile. The PCM CANNES system is basically featured by its decentralized structure in which a programmable unit provides remote management, through a 1 Mbit/s digital link, of the peripheral units acquiring the data. This structure offers the advantages of modularity, flexible use and easy adaption to specific requirements. A new unit in process of development, named UCDA, will considerably increase the performance of the system whilst ensuring perfect compatibility with the existing peripheral unit.
In early 1981, the Physical Science Laboratory (PSL) was tasked by the Air Force Geophysics Laboratory (AFGL) to develop a portable pulse-codemodulation (PCM) telemetry station that would acquire and support the high...
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ISBN:
(纸本)0876648936
In early 1981, the Physical Science Laboratory (PSL) was tasked by the Air Force Geophysics Laboratory (AFGL) to develop a portable pulse-codemodulation (PCM) telemetry station that would acquire and support the higher PCM data rates from Aries-type rocket payloads. The station would have to provide real-time and near real-time calibration, prelaunch and launch test support to AFGL researchers involved in space vehicle probe analysis. The station would also have to utilize a flexible software system, transportable hardware, and be easily expanded to meet the continually growing and varied needs of the researchers.
Intertechnique which manufactures the TM 77. 600, I. R. I. G. format decommutator, has had to extend the PCM message acquisition performance range to the DANIEL format, and has thus developed the TM 78. 420. The TM 78...
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ISBN:
(纸本)0876648936
Intertechnique which manufactures the TM 77. 600, I. R. I. G. format decommutator, has had to extend the PCM message acquisition performance range to the DANIEL format, and has thus developed the TM 78. 420. The TM 78420, capable therefore of acquiring both DANIEL and IRIG PCM messages, meets the requirements of the users of the Avions Marcel Dasault methods service telemetering station at Istres. This equipment provides for the acquisition and display, in different forms and in real time, of values of parameters contained in a PCM message.
The authors examine the performance implications of Adaptive Differential pulse code modulation (ADPCM) application in telecommunication networks. It is desirable to accommodate both national and international traffic...
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ISBN:
(纸本)0852963076
The authors examine the performance implications of Adaptive Differential pulse code modulation (ADPCM) application in telecommunication networks. It is desirable to accommodate both national and international traffic, and to support both voice and nonvoice services with minimum administrative complexity. Therefore, application of 32 kbit/s ADPCM in present day mixed analog/digital (and possibly nonclear channel) public networks, is expected to predominate on interchain toll trunks. Such a philosophy is consistent with transmission performance requirements, captures most of the economic benefit and is in line with long term network evolution towards bit-transparent multirate digital streams.
The advent of Bit Slice Processors and related architectures has produced numerous high performance PCM Data Simulators. Many of these fall into the category of stored program simulators, which give the user unlimited...
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ISBN:
(纸本)0876648936
The advent of Bit Slice Processors and related architectures has produced numerous high performance PCM Data Simulators. Many of these fall into the category of stored program simulators, which give the user unlimited flexibility and power. These simulators allow the user to program almost any imaginable format, with combinations of subframes, sub-subframes, and asynchronously embedded subframes. The drawback is that the user is forced to program the simulator using a very detailed machine level language which usually has no obvious relation to PCM frame formats. A new simulator architecture allows the user to describe the frame format to be simulated in familiar terms. This eliminates the need to learn yet another programming language or develop a Compiler. The user identifies common parameters such as frame length, subframe length, and where special words should be located. These special words can be unique sensor data words, a table of sensor data, ID counters, subframe slots and so on.
The authors introduce a modem that considers the modulator jointly with differential detection and uses spectral shaping techniques to achieve bandwidth and power efficiency in nonlinear channels. This new technique i...
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The authors introduce a modem that considers the modulator jointly with differential detection and uses spectral shaping techniques to achieve bandwidth and power efficiency in nonlinear channels. This new technique is called differentially detected controlled transition PSK (DCTPSK). The baseband waveshapes, eye diagrams, and signal space diagram of DCTPSK are given. Its bit-error-rate performance for differential detection is calculated, and its power spectral density is obtained. In linear and nonlinear channels, the compact spectrum of DCTPSK enables it to utilize the available bandwidth more efficiently than well-known modulation techniques such as DQPSK and DMSK. In a hardlimited channel, the bit-error-rate performance of DCTPSK is comparable to those of DPQSK and DMSK.
Supplemental catalog subcollection information: NASA Publication Collection; Astrophysics and Technical Documents; Generation of the maximal compatibles of pivot elements for a class of small sparse matrices is studie...
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Supplemental catalog subcollection information: NASA Publication Collection; Astrophysics and Technical Documents; Generation of the maximal compatibles of pivot elements for a class of small sparse matrices is studied. The algorithm involves a binary tre
An adaptive intraframc DPCM coding for broadcast television luminance signals with prediction based on minimum slope direction is presented. Every actual pel (picture clement) is considered as inactive or active from ...
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