TY - GEN
T1 - Performance analysis of a digital feedback AGC with constant settling time
AU - Liu, Anbang
AU - An, Jianping
AU - Wang, Aihua
PY - 2010
Y1 - 2010
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=79951730639&partnerID=8YFLogxK
U2 - 10.1109/ICCT.2010.5688549
DO - 10.1109/ICCT.2010.5688549
M3 - Conference contribution
AN - SCOPUS:79951730639
SN - 9781424468690
T3 - International Conference on Communication Technology Proceedings, ICCT
SP - 1060
EP - 1063
BT - Proceedings - 2010 IEEE 12th International Conference on Communication Technology, ICCT'2010
T2 - 2010 IEEE 12th International Conference on Communication Technology, ICCT'2010
Y2 - 11 November 2010 through 14 November 2010
ER -