| 摘要 |
A demodulator for OQPSK signals modulated with two unique words resolves eight possible cominbations of phase ambiguity which may product data error by first processing received IR and QR data in an integrated carrier loop/symbol synchronizer using a digital Costas loop with matched filters for correcting four of eight possible phase lock errors, and then the remaining four using a phase ambiguity resolver which detects the unique words to not only reverse the received IR and QR data channels, but to also invert (complement) the IR and/or QR data, or to at least complement the IR and QR data for systems using nontransparent codes that do not have rotation direction ambiguity.
|
