Fixed-point fixed-precision dynamic kernel function FFT processor for wideband signal detection

A 2.048 GSPS fixed-point fixed-precision dynamic kernel function FFT processor with variable truncation scheme (VTS) is proposed and implemented for real-time wideband signal detection. Using Xilinx System Generator, single-signal detection is demonstrated for a bandwidth of 912 MHz with 16 MHz channelization and output throughput rates of 62.5 ns. The proposed design has an averaged single-signal spurious-free dynamic range (SFDR) of 26 dB and the ability to detect a weak input signal utilizing only the often truncated least significant bits of the analog-to-digital converter. This is possible for a fixed-precision FFT design due to the embedded variable truncation scheme to extend the total dynamic range (DR) while preserving the SFDR relationship. Additional case studies utilizing different dynamic kernel function and inter-stage precision shows important area and performance trade-offs when utilized in a high-speed wideband FFT processor without the use of decimators.