LPC-BASED DTMF RECEIVER FOR SECONDARY SIGNALLING

摘要

LPC-BASED DTMF RECEIVER FOR SECONDARY SIGNALLING of the Invention A dual tone multi-frequency (DTMF) receiver for use in detecting digitally transmitted signals in the telephone industry. The receiver derives linear predictive coefficients for the digital signals in the data frame. This information is used to compute frequency response magnitudes at the DTMF frequencies. A plurality of magnitude comparisons are then performed to verify the presence of true DTMF signals and concurrently the frequency of these signals is obtained.