Apparatus and method for detecting duotone complex frequency signals

摘要

1. The technical field to which the invention described in the claims belongs;To a device and method for detecting a dual tone complex frequency in a voice mailing system (VMS).;2. Technical Problems to be Solved by the Invention;Prevent malfunction due to outgoing messages or noise when detecting dual tone complex frequencies through echo cancellation algorithms.;3. The point of the solution of the invention;The echo cancellation algorithm lowers or blocks the outgoing message for dual tone complex frequencies to detect duplex tone frequencies.;4. Important Uses of the Invention;It is used to detect duplex complex frequencies in the public switched telephone network.