Title :
Acquisition of the QPSK demodulator in the presence of interference
Author :
Ghazvinian, Farzad ; Chung, Char-Dir ; Wang, James
Author_Institution :
LinCom Corp., Los Angeles, CA, USA
fDate :
30 Sep-3 Oct 1990
Abstract :
The acquisition behavior of the tracking and data relay satellite system (TDRSS) receiver (a quadrative phase-shift keying (QPSK) demodulator using a dither lock detector) in the presence of interference from another user has been analyzed using a simulation model. The demodulator is composed of an automatic gain control, a QPSK Costas loop, a frequency sweep unit, lock test units, and a control unit. The simulation model has been tested for the following variables: signal and interference Doppler frequencies and phase offsets (with respect to initial voltage control oscillator setup), signal-to-interference ratio (SIR), and signal I/Q power ratio. The simulation results are discussed
Keywords :
demodulators; phase shift keying; radiofrequency interference; satellite relay systems; QPSK Costas loop; QPSK demodulator; TDRSS receiver; acquisition behavior; automatic gain control; control unit; frequency sweep unit; interference; interference Doppler frequencies; lock test units; phase offsets; signal Doppler frequencies; signal I/Q power ratio; signal-to-interference ratio; simulation model; tracking and data relay satellite system; Analytical models; Demodulation; Detectors; Gain control; Interference; Phase detection; Phase shift keying; Quadrature phase shift keying; Relays; Satellites;
Conference_Titel :
Military Communications Conference, 1990. MILCOM '90, Conference Record, A New Era. 1990 IEEE
Conference_Location :
Monterey, CA
DOI :
10.1109/MILCOM.1990.117560
