I believe that there is a way to calculate pseudorange (T_rx - T_tx) by using values reported in RXM-MEASX. T_rx is time of reception at the receiver, and T_tx is time when satellite has sent the signal. Values of interest are intCodePhase and codePhase. These are reported also by mobile devices during emergency call positioning over control plane in the LTE network. So called ue-assisted positioning. These same values are reported over LPP protocol. But I cannot understand how to use intCodePhase and codePhase to get pseudorange. What I really want it the time when signal was transmitted by a satellite. I see that u-blox device definitely can calculate pseudorange but there is no explanation how it does that. The time of transmission is needed to calculate position of satellite at the time when signal was sent and that is used later to calculate a position estimate of the mobile device.
In the 2G network wholeChips and fractionalChips are reported over RRLP, which represent same values but in different units (chips). These are also present in RXM-MEASX.
If there is someone here who can explain to me how to use intCodePhase and codePhase to calculate pseduorange I would be forever grateful.
I have seen a message from helge (https://forum.u-blox.com/index.php/3338/recovering-pseudorange-from-code-phase-rxm-measx), but I hope that his conclusion is not correct.