Hello.
As You can see from this Software log, modem part is damaged in your device:
This can be Software (modem firmware is damaged or You have written unsuitable firmware) or HW problem. Most likely, this is Software problem (problem with modem firmware).
At first, try re-flash the device with different firmwares and check, whether modem is correct (not Unknown). It is not possible to repair IMEI, if phone's modem part is damaged.