Walkie-Talkies have been widely used in many fields, such as public safety, emergency service, and logistics distribution business. However, the communication distance is very limited. The core goal of this project is to develop a cost-effective design to extend the communication range without affecting the quality of voice by applying the software defined radio technique. This enables Walkie-Talkies to be used for long distance communication among cities, or even countries.

Software Defined

Radio for Long

Distance Walkie-Talkie

Project Description

Future Development


This project is designed and implemented in three stages:

  1. 1.General design of the entire project such as brainstorm, diagrams, and pseudo code.

  2. 2.Building up a NBFM modulator and demodulator.

  3. 3.Data transmission and handling over the internet.       

However, this is only an instance of using software defined radio technique.  Other than the Walkie-talkies, the project can be used as a valuable reference for further designs in software defined radio field. For example, the range of Bluetooth can be extended by using the same idea. It can also lead to similar designs to enable other ubiquitous multimedia services, such as video streaming and virtual reality.


  1. 1.Walkie-Talkies can communicate in the same and different frequencies.

  2. 2.Solid voice quality.

  3. 3.Communication distance(from Walkie-Talkie to USRP1):
    30m indoor
    50m line of sight(LOS)

Detailed design specification can be found here.