Authors : Zi Hui Lau, Heng Siong Lim, Alan Wee Chiat Tan and M.L. Sim
Abstract: The main challenge in multi-standard wideband receiver design is to achieve good sensitivity in the presence of strong out-of-band interference. In a typical development cycle of a new direct conversion receiver iterative process of receiver design and bench measurement iscarried out until satisfactory interference rejection performance is achieved. This time consuming design cycleis required due to the lack of realistic simulation models for various impairments such as the Direct Current (DC) offset at the baseband stage. To address this problem, anempirical model for DC offset of direct conversion receiver due to strong out-of-band interference is proposed. The proposed model allows DC offset of a direct conversion receiver to be simulated in order to facilitate convenient interference rejection design and analysis. The model has been fitted to both constant envelope Frequency Modulation (FM) interference and Time-Division Multiple-Access (TDMA) interference using measurement data. Experiments show that the model is capable of predicting DC offset for different interference powers and frequencies.
Zi Hui Lau, Heng Siong Lim, Alan Wee Chiat Tan and M.L. Sim, 2017. Modeling and Simulation of DC Offset in Wideband Direct Conversion Receivers. Journal of Engineering and Applied Sciences, 12: 6492-6497.