Engineering topics
Publications and source records attributed to Couvillon, L. A., Jr..
A method and apparatus are described for synchronizing a received PCM communications signal without requiring a separate synchronizing channel. The technique provides digital correlation of the received signal with a reference signal, first with its unmodulated subcarrier and then with a bit sync code modulated subcarrier, where the code sequence length is equal in duration to each data bit.
Mariner 1969 communication system modified for thermoelectric outer planet spacecraft /TOPS/, noting X band addition to S band and associated problems
Statistical method estimates signal-to-noise ratios in an observed random voltage, such as the output of a telemetry receiver. Signals from a distant transmitting source, overlaid by noise signals, are monitored continuously.
A digital communicating system for automatically synchronizing signals for data detection is described. The systems consists of biphase modulating a subcarrier frequency by the binary data and transmitting a carrier phase modulated by this signal to a receiver, where coherent phase detection is employed to recover the subcarrier. Data detection is achieved by providing, in the receiver, a demodulated reference which is in synchronism with the unmodulated subcarrier in transmitting system. The output of the detector is passed through a matched filter where the signal is integrated over a bit period. As a result, random noise components are averaged out, so that the probability of detecting the correct data transmitted is maximized.
Automatic estimation of signal to noise ratio and other parameters in signal communication systems