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Digital signal processor modem

  • US 4,620,294 A
  • Filed: 09/09/1983
  • Issued: 10/28/1986
  • Est. Priority Date: 09/09/1983
  • Status: Expired due to Fees
First Claim
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1. A telephone network between an originate modem and an answer modem, at least one said modem comprising a two speed, full duplex modem for transmitting and receiving analog signals through said telephone network, said full duplex modem comprising:

  • (a) a data terminal means for transmitting and receiving digital data;

    (b) a microcomputer means in communication with the data terminal means;

    (c) a signal processor means in communication with the microcomputer means, said signal processor means further providing a means for storing a plurality of digital data samples corresponding to a sinusoidal waveform;

    (d) a converting means in communication with the signal processor means for converting digital data from the signal processor to the analog signal for transmission over the telephone network, and for converting the received analog signal from the telephone network to the digital data;

    (e) a filter means in communication with the converting means and the telephone network for filtering the analog signal for transmission between the converting means and the telephone network, and for filtering the received analog signal; and

    (f) a selecting means in communication with the microcomputer means for selecting a bit rate mode using the digital data from the data terminal means;

    said selecting means further providing a means responsive to the bit rate of the originate modem, to selectively communicate either a relatively higher bit rate by differential phase shift keying, or a relatively lower bit rate by frequency shift keying;

    the selecting means further providing a means for selecting digital data samples at intervals determined by the bit rate mode, to synthesize the digital data modulated for transmission through the converting means to the analog signal for transission through the filter means over the telephone network for communication between the originate modem and the answer modem.

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