Autocorrelating 2400 bps handshake sequence detector
US4868864A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1988 |
| Grant date | Sep 19, 1989 |
| Priority date | — |
| Expiry date | Apr 1, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0331
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An improved V.22 bis 2400 bits per second (bps) handshake sequence detector. An incoming phase keyed (PSK) handshake sequence is autocorrelated using a frequency shift keyed (FSK) receiver (101). The autocorrelated signal is then filtered by a low pass filter (106). The autocorrelated, low pass filtered signal is then alternately fed, at a 1200 Hz rate, to two detectors (114,116). Each of the detectors (114,116) looks for one half of the handshake sequence. The output of each detector (114,116) is provided to an OR-gate (122). The 2400 bps handshake sequence is declared to be detected when either one or both of the detectors (114,116) detects its corresponding portion of the sequence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.