In this paper, two-thread based signal tracking and acquisition process was designed. In general, the signal acquisition process is performed slower than the tracking process. For the reasons mentioned above, the results of acquisition from a few seconds later can be provide to tracking loop. To solve the problem, we proposed a correction method that the past of code phase can be corrected as currently code phase. We also performed an error analysis of the proposed method whether the corrected phase can apply to signal tracking or not. The performance and accuracy of the correction method is verified through signal tracking and acquisition test using real GNSS signal that was captured by USRP. As a result, although signal acquisition process does not operate on real-time, software receiver can be operated on real-time when the correction method is applied.

한국전자파학회논문지 (The Journal of Korean Institute of Electromagnetic Engineering and Science)

Modern internet-of-things (IoT) applications need voltage converters to efficiently supply power with a small active period at various load conditions. The energy losses in such voltage converters during transitions between sleep-active can be significant, especially when the converters deviate from their optimum load conditions. The proposed Switched Capacitor (SC) converter, fully integrated on chip, incorporates Split-Capacitor Charging (SCC) and Energy Recycling (ER) techniques to minimize the energy losses during the transitions. The converter consists of multiple capacitor banks and their size increases in a binary exponential fashion. It employs an LDO to support a wide range of output voltage levels and reduce output voltage ripple during energy recycling and Continuous phase. In addition, we introduce an efficient test circuit structure using an on-chip digital controller and reconfigurable load circuit. This test structure can eliminate the unwanted parasitic values and varying delays, which are commonly incurred in the conventional test structures of on-chip voltage converters with off-chip loads and external control signal generation. We implemented the proposed voltage converter with a complete on-chip test structure using a 0.13um CMOS process. Measurement results demonstrate a maximum efficiency of 86.83% for a load current of μA It also achieved an improvement of 64.44% in energy efficiency over conventional voltage converters for a short active period.

한국전자파학회논문지 (The Journal of Korean Institute of Electromagnetic Engineering and Science)

한국전자파학회논문지 (The Journal of Korean Institute of Electromagnetic Engineering and Science)