6.10.2 MBSFN reference signals
36.2113GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical channels and modulationRelease 17TS
MBSFN reference signals shall be transmitted in the MBSFN region of MBSFN subframes/slots only when the PMCH is transmitted. MBSFN reference signals are transmitted on antenna port 4.
For an MBMS-dedicated carrier configured with a single MBSFN area, and for a PMCH transmitted with 0.37 kHz subcarrier spacing in slot , which is indicated to contain MCCH by higher layer parameter MCCH-Config:
– for MBSFN reference signal pattern type 1, the UE may assume that MBSFN reference signals associated with the same are present in the three preceding slots to slot .
– for MBSFN reference signal pattern type 2, the UE may assume that MBSFN reference signals associated with the same are present in the preceding slot to slot .
MBSFN reference signals are defined for extended cyclic prefix only.
6.10.2.1 Sequence generation
6.10.2.1.1 Sequence generation for 15 kHz and 7.5 kHz subcarrier spacing
The MBSFN reference-signal sequence 
is defined by
where 
is the slot number within a radio frame and 
is the OFDM symbol number within the slot. The pseudo-random sequence 
is defined in clause 7.2. The pseudo-random sequence generator shall be initialised with 
at the start of each OFDM symbol.
6.10.2.1.2 Sequence generation for 1.25 kHz subcarrier spacing
The MBSFN reference-signal sequence 
is defined by
where 
is the subframe number within a radio frame and 
is the OFDM symbol number within the subframe. The pseudo-random sequence 
is defined in clause 7.2. The pseudo-random sequence generator shall be initialised with 
at the start of each OFDM symbol.
6.10.2.1.3 Sequence generation for 2.5 kHz subcarrier spacing
The MBSFN reference-signal sequence is defined by
where is the subframe number within a radio frame and is the OFDM symbol number within the subframe. The pseudo-random sequence is defined in clause 7.2. The pseudo-random sequence generator shall be initialised with
6.10.2.1.4 Sequence generation for 0.37 kHz subcarrier spacing
The MBSFN reference-signal sequence is defined by
where is the 3 ms slot number within the 40 ms period and is the OFDM symbol number within the slot. The pseudo-random sequence is defined in clause 7.2. The pseudo-random sequence generator shall be initialised with
6.10.2.2 Mapping to resource elements
6.10.2.2.1 Mapping to resource elements for 15 kHz and 7.5 kHz subcarrier spacing
The reference-signal sequence 
in OFDM symbol 
shall be mapped to complex-valued modulation symbols 
with 
according to
where
Figure 6.10.2.2-1 illustrates the resource elements used for MBSFN reference signal transmission in case of 
. In case of 
, the MBSFN reference signal shall be mapped to resource elements according to Figure 6.10.2.2-3. The notation 
is used to denote a resource element used for reference signal transmission on antenna port
.
Figure 6.10.2.2-1: Mapping of MBSFN reference signals (extended cyclic prefix, 
)
Figure 6.10.2.2-3: Mapping of MBSFN reference signals (extended cyclic prefix, 
)
6.10.2.2.2 Mapping to resource elements for 1.25 kHz
The reference-signal sequence 
in OFDM symbol 
shall be mapped to complex-valued modulation symbols 
with 
according to
where
6.10.2.2.3 Mapping to resource elements for 2.5 kHz subcarrier spacing
The reference-signal sequence in OFDM symbol shall be mapped to complex-valued modulation symbols with according to
where
6.10.2.2.4 Mapping to resource elements for 0.37 kHz subcarrier spacing
The reference-signal sequence in OFDM symbol shall be mapped to complex-valued modulation symbols with according to
when
and where is the 3ms absolute slot number, defined as is the 3 ms slot number as defined in clause 4.1 and
– for MBSFN reference signal pattern type 1
– for MBSFN reference signal pattern type 2