10.2.4 Narrowband physical broadcast channel

36.2113GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical channels and modulationRelease 17TS

10.2.4.1 Scrambling

Scrambling shall be done according to clause 6.6.1 with denoting the number of bits to be transmitted on the NPBCH. equals 1600 for normal cyclic prefix. The scrambling sequence shall be initialised with in radio frames fulfilling.

10.2.4.2 Modulation

Modulation shall be done according to clause 6.6.2 using the modulation scheme in Table 10.2.4.2-1

Table 10.2.4.2-1: Modulation schemes for NPBCH

Physical channel	Modulation schemes
NPBCH	QPSK

10.2.4.3 Layer mapping and precoding

Layer mapping and precoding shall be done according to clause 6.6.3 with . The UE shall assume antenna ports 2000 and 2001 are used for the transmission of the narrowband physical broadcast channel.

10.2.4.4 Mapping to resource elements

The block of complex-valued symbols for each antenna port is transmitted in subframe 0 for frame structure type 1 or subframe 9 for frame structure type 2 during 64 consecutive radio frames starting in each radio frame fulfilling . The quantity for normal cyclic prefix. Define as the block of complex-valued symbols to be transmitted in subframe 0 for frame structure type 1 or subframe 9 for frame structure type 2 of radio frame , as , with for normal cyclic prefix, and

where the scrambling sequence , is given by clause 7.2, and shall be initialized at the start of each radio frame with . The block of complex-valued symbols shall be mapped in sequence starting with to resource elements . The mapping to resource elements not reserved for transmission of reference signals shall be in increasing order of first the index, then the index . The first three OFDM symbols in a subframe shall not be used in the mapping process.

For the purpose of the mapping, the UE shall assume cell-specific reference signals for antenna ports 0-3 and narrowband reference signals for antenna ports 2000 and 2001 being present irrespective of the actual configuration. The frequency shift of the cell-specific reference signals shall be calculated by replacing with in the calculation of in clause 6.10.1.2.