Automatic Equalized Data Modem.
Abstract
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 bits/sec. The modem AN/USC-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 bits/sec and 2400 bits/sec for a total data rate of 2400 bits/sec or 4800 bits/sec. The modem design also includes an internal self test capability at any of the data rates. When completed the AN/USC-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 AN/USC-19 was tested in the presence of phase jitter over a simulated 3002 C2 circuit and met the contractual requirements. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1971
- Accession Number
- AD0883284
Entities
People
- David M. Motley
- Naif D. Salmon