Shi Zhiguo

Using interacting multiple model particle filter to track airborne targets hidden in blind Doppler

In airborne tracking, the blind Doppler makes the target undetectable, resulting in tracking difficulties. In this paper, we studied most possible blind-Doppler cases and summed them up into two types: targets’ intentional tangential flying to radar and unintentional flying with large tangential speed. We proposed an interacting multiple model (IMM) particle filter which combines a constant velocity model and an acceleration model to handle maneuvering motions. We compared the IMM particle filter with a previous particle filter solution. Simulation results showed that the IMM particle filter outperforms the method in previous works in terms of tracking accuracy and continuity.

Multiplexing Chaotic Signals Generated by Colpitts Oscillator and Chua Circuit Using Dual Synchronization

We demonstrate multiplexing chaotic signals generated by two totally different dynamic systems (one is a Colpitts oscillator and the other is a Chua circuit) using dual synchronization and propose a method to select the proper coupling parameters. In the response systems, the cross coupling method is used, in which the voltage difference between the sum of two master oscillators and one slave oscillator is converted to current and then feed into the other slave oscillator. The result in this letter offers a potential multiuser coherent chaotic communication scheme where different chaotic oscillators can be used in one system.

Robust Time Synchronization Scheme Combating Frequency Offset for IEEE 802.16a OFDM Systems

Orthogonal frequency division multiplexing (OFDM) is a promising technology for the next generation high-speed wireless communication. However, carrier frequency offset (CFO) induced by Doppler frequency drift and mismatch of the transceivers oscillators influences the time synchronization for OFDM systems. In this paper a robust time synchronization scheme compatible to IEEE 802.16a specification is proposed. It uses the symmetrical cross-correlation structure to eliminate the impact of frequency offset totally and to capture the accurate starting position of the FFT windows rapidly. Computer simulations demonstrate that the synchronization scheme is very efficient in combating large CFO