It has been shown that randomized Non-Return-to-Zero-Level code performs better than the other codes tested when the PCM data is bandpass-filtered and then summed with spectrally conditioned noise. These results apply...
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It has been shown that randomized Non-Return-to-Zero-Level code performs better than the other codes tested when the PCM data is bandpass-filtered and then summed with spectrally conditioned noise. These results apply to PCM bit synchronizers with ″good″ dc restorers. However, tests need to be run using several recorders to determine the effects under real-life conditions.
The increase of the variance of channel errors is of great importance for the optimization of DPCM picture transmission with the criterion of signal-to-noise ratio. In this paper the variance is determined for DPCM de...
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The increase of the variance of channel errors is of great importance for the optimization of DPCM picture transmission with the criterion of signal-to-noise ratio. In this paper the variance is determined for DPCM decoders with up to three predictor coefficients. For a finite number of picture elements the validity of the results is estimated.
Positive pulse stuffing synchronization applied to PCM transmission causes a new type of jitters. They are usually considered as the sum of three waveforms: framing and stuffing control jitter, stuffing jitter and wai...
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Positive pulse stuffing synchronization applied to PCM transmission causes a new type of jitters. They are usually considered as the sum of three waveforms: framing and stuffing control jitter, stuffing jitter and waiting time jitter (WTJ). The first and the second are easily suppressed in the (PLL) desynchronizer. Waiting time jitter contains very low frequency components and cannot be completely removed from the demultiplexed signal. In this paper WTJ is analyzed and its breaking down into higher-order low-frequency jitters is presented.
This paper will describe a single-channel codeC that includes both encode (A to D) and decode (D to A) functions, multiplexer time slot assignment under external microprocessor control and is capable of operating in s...
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Positive pulse stuffing synchronization applied to PCM transmission causes a new type of jitters. They are usually considered as the sum of three waveforms: framing and stuffing control jitter, stuffing jitter and wai...
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Positive pulse stuffing synchronization applied to PCM transmission causes a new type of jitters. They are usually considered as the sum of three waveforms: framing and stuffing control jitter, stuffing jitter and waiting time jitter (WTJ). The first and the second are easily suppressed in the (PLL) desynchronizer. Waiting time jitter contains very low frequency components and cannot be completely removed from the demultiplexed signal. In this paper WTJ is analyzed and its breaking down into higher-order low-frequency jitters is presented.
A computer oriented approach for the calculation of r. m. s. values of the jitter generated and accumulated along a chain of digital repeater is here presented. The method, based on a frequency domain analysis of the ...
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A computer oriented approach for the calculation of r. m. s. values of the jitter generated and accumulated along a chain of digital repeater is here presented. The method, based on a frequency domain analysis of the signal in the timing extraction path, seems to be particularly attractive when a large variety of different solutions have to be compared in the design of PCM systems. Few examples are produced;some of them are dealing with line block codes with band reduction never examined before in the literature.
A process to reduce burst errors in the differential PCM system with a leaky digital integrator is presented on the basis of finite Markov process approximation. The relationship between the burst error and the output...
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A process to reduce burst errors in the differential PCM system with a leaky digital integrator is presented on the basis of finite Markov process approximation. The relationship between the burst error and the output of the local decoder is investigated on the basis of binary leakage function.
The performance of ADPCM (Adaptive Differential PCM) coders connected in tandem has been analyzed for different bit rates as a function of the coder design parameters, by measuring the segmental signal-to-noise ratio ...
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The performance of ADPCM (Adaptive Differential PCM) coders connected in tandem has been analyzed for different bit rates as a function of the coder design parameters, by measuring the segmental signal-to-noise ratio (SNR). The results show that when many coders are connected in tandem it may be convenient to use a slower adaptation algorithm, while the parameter controlling the ″static performance″ should not be changed. This is explained in the paper by analyzing how different sources of degradations cumulate over successive codings and decodings. From the segmental SNR measures the category ratings that an average listener would assign to the output speech have been predicted too. Defining a communication link to be ″toll quality″ when the average rating is ″good″ or higher, it was found that more than six 5-bit ADPCM coders can be connected before the quality degrades appreciably. Connecting more than two 4-bit ADPCM coders in tandem results in a quality lower than the defined threshold.
A new line of PCM devices has been developed;this ″mini-din″ line meets the following requirements: compatibility with the existing equipment;flexibility;modular construction and easy operation. The device is recomm...
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A new line of PCM devices has been developed;this ″mini-din″ line meets the following requirements: compatibility with the existing equipment;flexibility;modular construction and easy operation. The device is recommended for application in medicine and biology, as well as in technology, for investigation of movable machine parts.
The output signal of a PCM transmission system consists of isolated signal jumps. It is demonstrated that the jumps occur at the end of a sweeping period and have a form of the response of the lowpass output filter wi...
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The output signal of a PCM transmission system consists of isolated signal jumps. It is demonstrated that the jumps occur at the end of a sweeping period and have a form of the response of the lowpass output filter with moderate raise of the high frequencies. The shift of the jumps to the end of the sweeping period excites the quantizing noise;this quantizing noise may, under certain circumstances, highlight some frequencies.
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