A wireless communication unit for compensating for Ionospheric group delay in a satellite communication system, the wireless communication unit comprising: a receiver (204, 206) configured to receive a multi-carrier signal from a satellite; and a processor coupled to the receiver and configured to: process the multi-carrier signal to produce a plurality of digital representations of individual carriers of the multi-carrier signal; perform a phase evaluation of the multi-carrier signal to determine phases of the plurality of the digital representations of individual carriers of the multi-carrier signal; detect cycle slips for the plurality of the digital representations of the individual carriers of the multi-carrier signal; perform cycle slip corrections of respective phases of the plurality of the digital representations of the individual carriers of the multi-carrier signal for the detected cycle slips; estimate, from the plurality of the digital representations of the individual carriers of the multi-carrier signal, a Total Electron Content, TEC, value associated with a communication path between the satellite and the wireless communication unit through Earth's Ionosphere; and apply compensation for Ionospheric group delay subjected to the multi-carrier signal based on the estimated TEC value, wherein the processor is further configured to perform a frequency discriminator estimation of each of the cycle slip corrections of the respective phases of the plurality of the digital representations of the individual carriers of the multi-carrier signal and average a plurality of discriminator estimation combinations for the individual carriers to estimate the TEC estimate value. a receiver (204, 206) configured to receive a multi-carrier signal from a satellite; and a processor coupled to the receiver and configured to: process the multi-carrier signal to produce a plurality of digital representations of individual carriers of the multi-carrier signal; perform a phase evaluation of the multi-carrier signal to determine phases of the plurality of the digital representations of individual carriers of the multi-carrier signal; detect cycle slips for the plurality of the digital representations of the individual carriers of the multi-carrier signal; perform cycle slip corrections of respective phases of the plurality of the digital representations of the individual carriers of the multi-carrier signal for the detected cycle slips; estimate, from the plurality of the digital representations of the individual carriers of the multi-carrier signal, a Total Electron Content, TEC, value associated with a communication path between the satellite and the wireless communication unit through Earth's Ionosphere; and apply compensation for Ionospheric group delay subjected to the multi-carrier signal based on the estimated TEC value, process the multi-carrier signal to produce a plurality of digital representations of individual carriers of the multi-carrier signal; perform a phase evaluation of the multi-carrier signal to determine phases of the plurality of the digital representations of individual carriers of the multi-carrier signal; detect cycle slips for the plurality of the digital representations of the individual carriers of the multi-carrier signal; perform cycle slip corrections of respective phases of the plurality of the digital representations of the individual carriers of the multi-carrier signal for the detected cycle slips; estimate, from the plurality of the digital representations of the individual carriers of the multi-carrier signal, a Total Electron Content, TEC, value associated with a communication path between the satellite and the wireless communication unit through Earth's Ionosphere; and apply compensation for Ionospheric group delay subjected to the multi-carrier signal based on the estimated TEC value,