A Flexible and Compact Digital Front-End Design for Wideband Software Radio Receivers

The Digital front-end technique (DFE) is a key element of software-defined radio receivers. With this technique, any signal of interest can be extracted and shaped from the wideband radio frequency (RF) input signal. This paper aims to study, design, and implement a flexible wideband DFE architecture that can be compactly implemented on field programmable gate array (FPGA). The tradeoff between cost and computing complexity is analyzed and compared. Furthermore, a flexible and compact 32-channel DFE is implemented on single-chip FPGA. The architecture includes polyphase filter banks, fine tuning, channel filtering and gain control blocks. Our DFE parameters for each output channel can be programmed individually. It supports 0.01 Hz tuning precision and end-to-end dynamic range of around 80dB at sample rate of 200MSPS.