This page contains a handfull of links that have helped me understand what's going on

https://www.slideshare.net/ChiehChun/lte-training-course-128947387

https://www.sharetechnote.com/html/Handbook_LTE_PhyParameter_DL_FDD.html

https://www.sharetechnote.com/html/BasicProcedure_LTE_TimeSync.html

https://twitter.com/DiGMi1/status/1463076874926673927

https://github.com/tmbinc/random/tree/master/dji/ocusync2

https://www.sharetechnote.com/html/Handbook_LTE_PseudoRandomSequence.html