DocumentCode :
2082591
Title :
Performance analysis of a digital feedback AGC with constant settling time
Author :
Liu, Anbang ; An, Jianping ; Wang, Aihua
Author_Institution :
Sch. of Inf. & Electron., Beijing Inst. of Technol., Beijing, China
fYear :
2010
fDate :
11-14 Nov. 2010
Firstpage :
1060
Lastpage :
1063
Abstract :
A digital feedback automatic gain control (DFAGC) with the constant settling time is presented for the stability of the Phase Locked Loop in the QPSK demodulation. The DFAGC consists of an exponential gain controlled amplifier and a logarithmic amplifier, which gets the constant gain settling time independent of the input signal amplitude. This scheme allows using the linear system theory directly analyze the DAGC performance. So the mathematical model and the backward difference equation are given to investigate the settling time, and the transfer function given to obtain the transient response and the DFAGC tracking performance. Finally, it is verified by simulations that the analysis results closely coincide with the settling time and the DFAGC characteristic in high SNR, and the linear system theory analysis method concisely gives the insight of the proposed scheme.
Keywords :
amplifiers; automatic gain control; phase locked loops; quadrature phase shift keying; transfer functions; transient response; QPSK demodulation; backward difference equation; digital feedback automatic gain control; exponential gain controlled amplifier; logarithmic amplifier; phase locked loop; settling time; transfer function; transient response; Performance analysis;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Communication Technology (ICCT), 2010 12th IEEE International Conference on
Conference_Location :
Nanjing
Print_ISBN :
978-1-4244-6868-3
Type :
conf
DOI :
10.1109/ICCT.2010.5688549
Filename :
5688549
Link To Document :
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