Title :
Design of a Digital Automatic Gain Control with Backward Difference Transformation
Author :
Liu, Anbang ; An, Jianping ; Wang, Aihua
Author_Institution :
Sch. of Inf. & Electron., Beijing Inst. of Technol., Beijing, China
Abstract :
The design of a digital Automatic Gain Control (AGC) prior to a digital Phase Locked Loop (PLL) that uses the backward difference Transformation is described. This design is applicable to an Automatic Gain Control with an exponential gain controlled amplifier and a logarithmic amplifier, which obtains a gain settling time independent of the absolute gain. Use of this design permits the designer to specify the performance of the digital AGC system with respect to the similar analog AGC. A mathematical model for the digital AGC for the backward difference equation is established to investigate the characteristics of the scheme. Based on the backward difference equation, we analyze the transfer function and the transient response of the AGC. It has been verified that the results by the digital AGC agree with the analog AGC obtained on the condition that the sample interval is small.
Keywords :
amplifiers; automatic gain control; phase locked loops; radio receivers; software radio; transfer functions; transient response; PLL; analog AGC; backward difference equation; backward difference transformation; digital AGC system; digital automatic gain control; digital phase locked loop; exponential gain controlled amplifier; logarithmic amplifier; mathematical model; software radio receivers; transfer function; transient response; Bandwidth; Gain control; Linear systems; Phase locked loops; Servomotors; Stability analysis; Transfer functions;
Conference_Titel :
Wireless Communications Networking and Mobile Computing (WiCOM), 2010 6th International Conference on
Conference_Location :
Chengdu
Print_ISBN :
978-1-4244-3708-5
Electronic_ISBN :
978-1-4244-3709-2
DOI :
10.1109/WICOM.2010.5600986
