A new low-voltage, all-in-one ESD (electrostatic discharging) protection circuit was designed. One such ESD protection unit is enough to protect each I/O pad against ESD stresses of all modes, i.e., from I/O to power supply and ground positively and negatively. This novel ESD circuit features adjustable trigger-voltage, i.e., 5 V to 60 V, with low turn-on threshold down to 5 V, symmetric active discharging channels in all directions, fast response time of 0.1 to 0.3 ns, and high ESD performance/area ratio of greater than 80 V per micrometer width. It was implemented in commercial BiCMOS technologies and achieved 14 kV human body model (HBM) and 15 kV air-gap IEC ESD protection levels. This compact ESD structure can not only provide adequate ESD protection, but also minimize the ESD-induced parasitic effects, which makes it a suitable ESD protection solution for mixed-signal and RF ICs in very deep sub-micron regime.

A differential inter-symbol interference (ISI) cancellation method for time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) systems is proposed. The differential output of an OFDM system can greatly reduce the impact of ISI in the frequency domain and it constructs a convolutional structure, thus the Viterbi decoding algorithm can be used to recover the transmitted information from the output signal. Simulation results show the effectiveness of the proposed method.

China has experienced fast growth in mobile communications. Now, China is the world largest mobile communication country with about 500 million users. Wide applications of mobile communications are giving strong pull to the research and development on the broadband wireless communication technology to meet the fast growing demand for high speed access into the information infrastructure. This makes the R&D on wireless technology play great role in the Chinese High-Tech program. This paper will review the key project--FuTURE (Future Technology for Universal Radio Environment)--development of the 863 program, which represents the Chinese efforts towards IMT-advance. Taking some works done in the Tsinghua National Laboratory for Information Science and Technology as examples, the paper will show what has been made in China on the broadband wireless technology, including the trial network in Shanghai.