APPARATUS, METHOD AND SOFTWARE MODEM FOR UTILIZING ENVELOPE DELAY DISTORTION CHARATERISTICS TO DETERMINE A SYMBOL RATE AND A CARRIER FREQUENCY FOR DATA TRANSFER

摘要

According to the invention, the apparatus, software modem, and method for a data communication device such as a modem (100, 101) for optimizing the bit rate to determine a symbol rate and carrier frequency for data transmission and reception from the received probe signal It is provided. Various embodiments using the processor 108 or digital signal processor (106) typically receives the probe signal that involve noise and other distortions in particular envelope delay distortion. Various exemplary methods and devices for example, then ITU V.34 particular transmit pre-selected protocol in which - the variation of the preemphasis filter and correlation, or attenuation distortion as that related to the matter as being related directly or indirectly to the envelope delay distortion determined. Then, using the variation of the delay distortion in determining the optimal symbol rate and carrier frequency for data transmission and reception to the exclusion of any symbol rate and carrier frequency corresponding to this.