5A.7a Preamble Allocation and Preamble Transmit Power
25.2213GPPPhysical channels and mapping of transport channels onto physical channels (TDD)Release 17TS
When the entire carrier is dedicated to MBSFN, for all timeslots employing MBSFN operation, only a single preamble is needed, i.e. KCell=1, then all physical channels in such timeslots employ the same preamble with the same allocation strategies.
There shall be no offset between the sum of the powers allocated to all preambles in a timeslot and the sum of the powers allocated to the data symbol fields. The transmit power within a timeslot is hence constant.