The Use of Resettable Integrators or Conventional Filters in Time-Division Data Transmission Systems

摘要

This report establishes the 'effective noise power bandwidths' and 'noise reduction factors' of a resettable integrator and of conventional passive lowpass filters. It then discusses the use of the resettable integrator with its necessary sample and hold circuit, as compared to the use of a passive lowpass filter which follows the receiver demodulator in time-division data transmission systems, such as telemetry links. It is concluded that since the overall lowpass bandwidth is determined by the conventional output lowpass filter necessary for removing the sampling 'noise' (quantum steps), then any other filter device is redundant, provided the demodulator does not sensibly alter the statistical properties of the input random noise. As a germane and highly important side issue, a more logical method for selecting the sampling rate in time-division systems is also discussed. (Author)