what cadence are you looking at?

what does carrier data mean? (IN GPS)

The question is a bit wired. You can simply find all observation data (including carrier phase) in RINEX files which can be easily downloaded through IGS:

http://igscb.jpl.nasa.gov/components/compindex.html

Thank you all. Here is an answer for carrier phase measurement.

A carrier phase measurement is a measurement of the phase of the arriving carrier wave signal from the gps satellite.  Think of it this way - as the radio signal from the GPS satellite travels from the satellite to your receiver it completes some fractional number of cycles of oscillation.  That means that the distance from the satellite receiver to you is some fractional number of wavelengths - say 100 million and 1/2 wavelengths.  The carrier phase measurement gives you the fractional value of 1/2 wavelength, or 180 degrees of phase. By obserbing this phase we can get centimer level accuracy in positon , and very low error an attitude.

Dear,

Milad Asgarimehr . i downloaded the data. i got some problem to read data. could you please help ?? and how the file is organised ??

The full format description of the files are also provided by IGS, as Grzegorz Nykiel mentions. You can find the correct version description and extract the information you need.

You could always look at the carrier SNR value (usually found around -40 dB) and generate data with gaussian noise added. Then try carrier phase and frequency tracking for simulation purpose.