Method and apparatus for receiving system information in wireless communication system
The method for receiving system information by a terminal in a wireless communication system according to one embodiment of the present invention comprises: a step of receiving a subframe; and a step of performing, for a physical broadcast channel (PBCH) in a predetermined resource region of the subframe, blind decoding based on a plurality of sequences to be masked to a CRC parity bit. If a cell-specific reference signal (CRS) does not exist in the subframe, each of the plurality of sequences indicates pieces of individual information contained in one or more of a reference signal type set, a demodulation reference signal (DMRS) antenna port information set and diversity scheme information set.
1. A method for receiving system information at a user equipment (UE) in a wireless communication system, the method comprising:
receiving a subframe; and
performing blind decoding for a physical broadcast channel (PBCH) in a predetermined resource region of the subframe, based on a plurality of sequences masked on cyclic redundancy check (CRC) parity bits,
wherein, when a cell-specific reference signal (CRS) is not present in the subframe,
each of the plurality of sequences indicates one of a plurality of demodulation reference signal (DMRS) antenna port sets, or
each of the plurality of sequences indicates one of a plurality of diversity scheme sets, or
each of the plurality of sequences indicates one of a tracking reference signal (TRS) and a DMRS as a type of a reference signal,
wherein, when each of the plurality of sequences indicates one of the plurality of diversity scheme sets, a sequence among the plurality of sequences indicates that precoding of the system information has been performed based on the following table:
Frequency
Frequency
Frequency
Frequency
unit re-
unit re-
unit re-
unit re-
source
source
source
source n
n + 1
n + 2
n + 3
Antenna port 0
S0
S1
0
0
Antenna port 1
0
0
S2
S3
Antenna port 2
−S1*
S0*
0
0
Antenna port 3
0
0
−S3*
S2*
wherein Sx denotes system information mapped to layer x, and *denotes a complex conjugate.
2. The method according to claim 1 ,
wherein a sequence masked on a PBCH CRC parity bit among the plurality of sequences indicates at least one DMRS antenna port associated with the PBCH.
3. The method according to claim 1 ,
wherein each of the plurality of sequences indicates one of DMRS antenna ports { 7 }, { 7 , 9 }, and { 7 , 8 , 9 , 10 }, respectively.
4. The method according to claim 1 , further comprising:
determining a number of antenna ports for an enhanced physical downlink control channel (EPDCCH) based on a number of antenna ports for the PBCH, when the EPDCCH and the PBCH are multiplexed in the subframe.
5. The method according to claim 1 ,
wherein a sequence among the plurality of sequences indicates the TRS as the type of a reference signal associated with decoding of the system information, and
wherein another sequence among the plurality of sequences indicates the DMRS as the type of the reference signal associated with decoding of the system information.
6. The method according to claim 5 ,
wherein the another sequence indicates DMRS antenna ports { 7 , 9 } or { 7 , 8 , 9 , 10 }.
7. The method according to claim 1 , wherein, when the predetermined resource region includes fewer than 6 resource blocks, a precoding matrix used in transmitting the system information has a matrix according to the following table as a constituent matrix:
Number of layers
Constituent matrix
2
[
1
0
0
e
-
j
2
π
i
/
2
]
3
[
1
0
0
0
e
-
j
2
π
i
/
3
0
0
0
e
-
j
4
π
i
/
3
]
4
[
1
0
0
0
0
e
-
j
2
π
i
/
4
0
0
0
0
e
-
j
4
π
i
/
4
0
0
0
0
e
-
j
6
π
i
/
4
]
.
8. The method according to claim 1 , wherein, when a physical downlink shared channel (PDSCH) and the PBCH are multiplexed in the subframe, and a first antenna port associated with the PDSCH differs from a second antenna port associated with the PBCH, the UE performs rate matching in consideration of the second antenna port in receiving the PDSCH.
9. A user equipment in a wireless communication, the user equipment comprising:
a radio frequency (RF) module; and
a processor operably coupled with the RF module,
wherein the processor is configured to perform blind decoding for a physical broadcast channel (PBCH) in a predetermined resource region of a received subframe, based on a plurality of sequences masked on cyclic redundancy check (CRC) parity bits,
wherein, when a cell-specific reference signal (CRS) is not present in the subframe,
each of the plurality of sequences indicates one of a plurality of demodulation reference signal (DMRS) antenna port sets, or
each of the plurality of sequences indicates one of a plurality of diversity scheme sets, or
each of the plurality of sequences indicates one of a tracking reference signal (TRS) and a DMRS as a type of a reference signal,
wherein, when each of the plurality of sequences indicates one of the plurality of diversity scheme sets, a sequence among the plurality of sequences indicates that precoding of the system information has been performed based on the following table:
Frequency
Frequency
Frequency
Frequency
unit re-
unit re-
unit re-
unit re-
source
source
source
source n
n + 1
n + 2
n + 3
Antenna port 0
S0
S1
0
0
Antenna port 1
0
0
S2
S3
Antenna port 2
−S1*
S0*
0
0
Antenna port 3
0
0
−S3*
S2*
wherein Sx denotes system information mapped to layer x, and *denotes a complex conjugate.