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Automatic Equalized Data Modem.

Descriptive Note:

Final technical rept.,

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The objective of this contract was the design and construction of a developmental model of an automatically equalized data modem, of full duplex design capable of operation over normal schedule 4B now 3002 C-2 conditioned telephone voice circuits at rates of 1200, 2400, or 4800 bitssec. The modem ANUSC-19 utilized decision feedback equalization technique together with a virtual carrier phase lock loop and fast residual channel learning techniques. The modem is constructed in an aluminum RFI-EMI shielded box, 17x7x6.75 inch width with a 19 inch rack mount front panel. This box houses 14 specially designed circuit boards which also contain six special purpose MOS-LSI chips designed by Autonetics. The modem is capable of multiplexing up to four separate input channels at any combination of 1200 bitssec and 2400 bitssec for a total data rate of 2400 bitssec or 4800 bitssec. The modem design also includes an internal self test capability at any of the data rates. When completed the ANUSC-19 was tested over simulated 3002, 3002 C1, and 3002 C2 as well as a leased 3002 C2 conditioned telephone circuits and met with contractual bit error rate requirements. Additionally, the ANUSC-19 was tested in the presence of phase jitter over a simulated 3002 C2 circuit and met the contractual requirements. Author

Subject Categories:

  • Electrical and Electronic Equipment
  • Voice Communications

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