In a software GNSS receiver, all digital processing is performed by a general purpose microprocessor.
In this approach, a small amount of inexpensive hardware is still needed, known as the frontend, that digitizes the signal from the satellites.
The microprocessor can then work on this raw digital stream to implement the GNSS functionality.
However, there already exist operational solutions based on the software approach able to run on low-cost microprocessors.
Software GNSS receivers are expected to increase their market share or even take over in the near future, following the development of the computational capabilities of the microprocessors (Moore's law).