Research on high-performance, real-time periodic signal detection method based on field-programmable gate arrays (FPGAs)

Long-Time Coherent Integration (LTCI) utilizes digital integration to combine multiple coherent cycles, thereby improving the signal-to-noise ratio (SNR). Our previous work introduced single-bit LTCI, an approach optimized for FPGA implementation, but faced challenges of output saturation at high SNR levels and inherent limitations in SNR gain (SNRG), which are insufficient for certain applications. This paper presents a threshold tracking method that improves the performance of single-bit LTCI in high-SNR scenarios. In addition, a sampling rate enhancement technique and a Kalman filtering method are introduced to further enhance the SNR of the processed signals. An FPGA-based prototype was developed to validate these methods. The results demonstrate that the threshold tracking method extends the measurable input SNR range to 30. Under the specified conditions, the sampling rate enhancement technique yields a 30% improvement in SNR over the original method, while the Kalman filter reduces noise levels to 60% of their original values.