Design and compensation of second-order sub-sampling digital frontend

Hong Mei Wang, Jae Hyung Kim*, Sang Hyuk Lee, Hyung Jung Kim, Jin Up Kim, Jong Seog Koh

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


The problem of designing a digital frontend (DFE) was considered which can dynamically access or sense dual bands in any radio frequency (RF) regions without requiring hardware changes. In particular, second-order bandpass sampling (BPS) as a technique that enables to realize the multiband reception function was discussed. In a second-order BPS system, digital reconstruction filters were utilized to eliminate the interferences generated while down converting arbitrarily positioned RF-band signals by using the direct digitization method. However, the inaccuracy in the phase shift or the amplitude mismatch between the two sample streams may cause insufficient rejection of interference. Practical problems were studied, such as performance degradation in signal-to-interference ratio (SIR) and compensation methods to overcome them. In order to demonstrate the secondorder BPS as a flexible DFE suitable for software-defined radio (SDR) or cognitive radio (CR), a DFE testbed with a reconfigurable structure was implemented. Moreover, with a view to further demonstrate the proposed compensation algorithms, experimental results show that dual bands are received simultaneously.

Original languageEnglish
Pages (from-to)408-416
Number of pages9
JournalJournal of Central South University of Technology (English Edition)
Issue number2
Publication statusPublished - Feb 2012


  • Bandpass sampling
  • Reconfiguration
  • Second order band-pass sampling
  • Software-defined radio

Cite this