Approaches to multiple 8-kHz nonuniform sampling in PCM channel banks

Author

Messerschmitt, David G.

Volume

22

Issue

1

fYear

1975

fDate

1/1/1975 12:00:00 AM

Firstpage

47

Lastpage

55

Abstract

Methods of compensating for the nonuniform sampling resulting from the frame format of PCM channel banks, when the basic sampling rate (usually 8 kHz) is increased by an even factor $N$ , are considered. This situation arises when it is desired to provide greater than 4-kHz bandwidth channels on a PCM system by the modification of an existing channel bank. For the present 24-channel frame format, the distortion introduced is 41.9 dB below the signal power for $N = 2$ and greater than 30 dB for $N = 4$ . Remedies include time delays at the input (implemented by delaying sampling) and output or special output filtering. The output filter requires a Hilbert transform for $N = 2$ , and has a phase discontinuity for $N = 4$ . This phase discontinuity can be eliminated at the expense of allowing some residual distortion.

Keywords

Channel bank filters; D/A converters; Digital-to-analog (D/A) conversion; PCM communication; Sampled signals; Time-varying and switched networks and systems; Bandwidth; Channel bank filters; Delay effects; Filtering; Nonuniform sampling; Phase change materials; Phase distortion; Sampling methods; Signal design; Telephony;

fLanguage

English

Journal_Title

Circuits and Systems, IEEE Transactions on

Publisher

ieee

ISSN

0098-4094

Type

jour

DOI

10.1109/TCS.1975.1083966

Filename

1083966