You can communicate with a GPS device in MATLAB via a serial connection (COM port). Many GPS devices will expose a virtual COM port when plugged into a USB port. You can then connect to it using the SERIAL function in MATLAB. For example:
gps = serial('COM1');
fopen(gps);
% Read a line of text from the input stream
data = fgetl(gps);
% [Other processing]
% Close the connection
fclose(gps);
delete(gps);
See the attached function, which shows your current location on Google Maps, for a more detailed example.
