An OQPSK (offset quadrature phase shift keying) burst demodulator using a reverse modulation scheme for low E//b/N//0 operation is described. A carrier-recovery circuit using a reverse modulation scheme for OQPSK signals is analyzed, and its performance is clarified. A novel binary transmit-receive code for OQPSK burst signals is proposed to reduce the recovered carrier phase error. To additionally reduce the recovered carrier phase error, a digitally controlled tracking filter is proposed, and an automatic frequency control LSI has been developed for the tracking filter. Experimental results show that a prototype 130-Mb/s OQPSK burst demodulator using a reverse modulation scheme works stably with low carrier cycle slipping rate even in a low E//b/N//0 environment.
|Number of pages||7|
|Journal||Conference Record - International Conference on Communications|
|Publication status||Published - 1987 Dec 1|
ASJC Scopus subject areas
- Computer Networks and Communications
- Electrical and Electronic Engineering