An FPGA Design Technique to Receive Multiple Wireless Protocols with the Same RF Front End

Abstract

Field Programmable Gate Arrays (FPGAs) are widely used in wireless networking transceivers, however they typically are designed to process one specific wireless protocol. Our research group is investigating how to make FPGA designs more versatile. In this paper, we present an FPGA design that can receive either Wi-Fi or LTE signals by determining which signal is being received, and then applying the appropriate processing. We initially receive all signals at a 30.72 MHz sampling rate, an underlying sampling rate for LTE. A unique matched filter is designed that allows us to detect the Wi-Fi preamble at this rate despite the fact that it is transmitted at 20MHz. Results show that we can successfully distinguish between the two signals and further decode received packets by switching to the appropriate sampling rate after the type of signal has been detected.