dtmfReceiver(dtmfPulse)

Converts a DTMF pulse or (pulse train) into the corresponding character(s)

Syntax

o_dtmfReceiver(dtmfPulse)

dtmfPulse: waveform - any DTMF-coded signal pulse

OR  

dtmfPulse: scalar record that defines a pulse train. Three fields:

signal: waveform - the dtmf signal

pulseLen: real64 scalar - length of the pulses in seconds

nullLen: real64 scalar - length of the pulse train nulls in seconds

return: string - character(s) that correspond to the given pulse.

Usage

This function takes a general two-tone DTMF pulse train with or without noise and other signals and derives a best estimate of the intended encoded characters. If the input is a single waveform then it is assumed that a single pulse is present and a single character is derived. If the input is a record with the requisite three fields then a pulse train is processed and converted to a multiple character string.

Location

menu: veeos ==> signal processing ==> modules ==> dtmfReceiver

library: sigLib

Example

Notes

This function implements a DTMF receiver using a tuned narrow-band receiver and as such is highly noise resistant.

Reference

DTMF is a very simple standard consisting of two audio frequencies and developed to enable simple data signaling over telephone lines.

Dependencies

o_dtmfRcvPulse()

Supported On

VEE 7.0+, All platforms.

See Also

dtmfCode, dtmfDecode, dtmfPulse, dtmfRcvPulse, dtmfSigGen