Overview

We were tasked to design a filter to suppress interference and obtain the message using a wireless medium.

You are required to employ Pluto Adalm, RTL-SDR, Analog Discovery 2, LTSPICE, GNURadio with the given specifications (Design A, B or C) for your group, and design a filter to suppress the interference at Intermediate Frequency (IF, signal from the RTL-SDR).

Our constraints are summarised below:

Parameters Unit Amplitude
Signal Frequency Hz 160k
Interference Frequency Hz 320k
Signal Amplitude Nil 0.15
Interference Amplitude Nil 0.3

(Summary of design constraints)

Project Components

image of RTL SDR and Adalm Pluto

(From left to right: RTL SDR, Adalm Pluto)

  • RTL SDR: Software-defined radio to receive signals
  • Adalm Pluto: to transmit signals

Proof of Concept

We simulated the filter design using LTSpice and we chose our best simulation to be converted into actual hardware prototype as shown below.

image of filter design

(Filter design on breadboard)

During demonstration, we are able to achieve a PSR (actual) of around 0.1 at 100% interference level.

image of psr during demo

(PSR)