Search

This paper introduces a method which can improve accuracy for estimating parameters of linear frequency modulation (LFM) signal. The proposed approach is based on Short Time Fourier Transform (STFT). After STFT, spike filter and detecting threshold are used to achieve high precision of parameters estimation in the time domain. What's more, moving windows and frequency compensation are done to improve accuracy for frequency parameters estimation. Simulation results show that this method is effective in improving the accuracy for parameters estimation of LFM and requires only moderate computation ability. Thus it can be widely applied. (4 pages)

Digital Radio Frequency Memory (DRFM) has been widely used for the storage of radio frequency and microwave signals. As the frequency and bandwidth are large, the implement of DRFM is limited by the speed of digital devices. A design is proposed to solve this problem based on leading technology such as poly-phase filter, Parallel-decomposition convolution and Partition of the coefficient sequence, RapidIO technology. The design shown in this paper is useful in complicate radar echo signal simulation with broadband coverage and high-speed data rate.

The range gate pull off (RGPO) results in a disaster to radar target tracking. It is assumed that the jamming (i.e., RGPO measurement, the following are the same) pulls the range gate backwards in the conventional methods. However, the RGPO for some radar, e.g., linear frequency modulation radar, can pull onwards by modulating the Doppler frequency to the returned signal. Whatpsilas more, in conventional methods targets were modeled as point targets. Nevertheless, further studies are required when the target and jamming are extended in real-world environment. Previous researches failed to consider the lasting time of the anti-RGPO process, which is crucial under a certain condition. To avoid these drawbacks, a method based on memory tracking is studied. The method can detect the existence of RGPO and recognize the pulling-off direction of the jamming; and the method can make the jamming get out of the range gate earlier than the true target, thus the RGPO has little effect on the tracking. Some important factors in the method are analyzed. Experiments show that the total time of the anti-RGPO process is short.

An approach of implementing time-domain real-time convolution processor into multi-chip FPGA hardware platform is stated and the application of the convolution processor in radar echo signal simulator is introduced. With high speed input data flow, the algorithm of parallel-decomposition and coefficient-partitioned convolution is proposed to meet the real-time requirement. With the decomposition of the input data and the coefficient sequence, the input data flow from ADC with high sample rate can be slow down; with the partition of the coefficient sequence, the overall convolution process can be partitioned into several sub-convolutions and implementing into multi-chip FPGA hardware platform. The algorithm and design architecture shown in the paper is useful in complicate radar echo signal simulation with broadband coverage and low input-output delay.