Scrambling of physical broadcast channel (PBCH)
A user equipment (UE) can include processing circuitry configured to decode physical broadcast channel (PBCH) information received from a base station (BS). The decoded PBCH information includes a scrambled PBCH payload and an unscrambled bit sequence. A scrambling sequence is generated based on time information signaling within the unscrambled bit sequence. The scrambled PBCH payload is de-scrambled using the scrambling sequence, to obtain master information block (MIB) information. System information block (SIB) information is decoded based on the MIB information. The decoded PBCH information includes cyclic redundancy check (CRC) information. The scrambled PBCH payload and the unscrambled bit sequence can be verified based on the CRC information. The time information signaling includes one or more bits of a system frame number (SFN).
1 . A non-transitory computer readable medium (NTCRM), comprising:
program instructions configured to cause a user equipment (UE) to:
receive, from a base station (BS), physical broadcast channel (PBCH) information, the PBCH information comprising a PBCH payload, the PBCH payload including a portion of system timing information and cyclic redundancy check (CRC) information; and
decode the PBCH information, wherein the PBCH payload is scrambled by a scrambling sequence, wherein scrambling bits of the scrambling sequence are set to 0 for the PBCH payload comprising the portion of the system timing information and excludes the portion of the system timing information from scrambling, wherein the scrambling sequence is based on the portion of the system timing information, wherein the PBCH payload includes the system timing information.
2 . The NTCRM of claim 1 , wherein second timing information, not included in the system timing information, is carried on a PBCH demodulation reference signal (DMRS).
3 . The NTCRM of claim 2 , wherein the second timing information is 2 or 3 bits of a synchronization signal block index.
4 . The NTCRM of claim 1 , wherein the PBCH information is further scrambled with a second scrambling sequence based on cell-specific information associated with a cell of the BS.
5 . The NTCRM of claim 4 , wherein the cell-specific information is a cell ID of the cell.
6 . The NTCRM of claim 1 , wherein the scrambling sequence is a length-31 Gold sequence generated using two M-sequences.
7 . The NTCRM of claim 1 , wherein the system timing information includes one or more of the following:
a system frame number, SFN;
a half radio frame index; and
one or more bits of a synchronization signal block index.
8 . The NTCRM of claim 1 , wherein the PBCH payload comprises master information block (MIB) signaling.
9 . A method, comprising:
obtaining a physical broadcast channel (PBCH) payload including a portion of system timing information;
scrambling the PBCH payload by a scrambling sequence, wherein scrambling bits of the scrambling sequence are set to 0 for the PBCH payload comprising the portion of the system timing information and excludes the portion of the system timing information from scrambling, wherein the scrambling sequence is based on the portion of the system timing information, wherein the PBCH payload includes the system timing information;
appending cyclic redundancy check (CRC) information to the PBCH payload to obtain PBCH information; and
encoding the PBCH information for transmission.
10 . The method of claim 9 , wherein second timing information, not included in the system timing information, is carried on a PBCH demodulation reference signal (DMRS).
11 . The method of claim 10 , wherein the second timing information is 2 or 3 bits of a synchronization signal block index.
12 . The method of claim 9 , wherein the PBCH information is further scrambled with a second scrambling sequence based on cell-specific information associated with a cell.
13 . The method of claim 12 , wherein the cell-specific information is a cell ID of the cell.
14 . The method of claim 9 , wherein the scrambling sequence is a length-31 Gold sequence generated using two M-sequences.
15 . The method of claim 9 , wherein the system timing information includes one or more of the following:
a system frame number, SFN;
a half radio frame index; and
one or more bits of a synchronization signal block index.
16 . The method of claim 9 , wherein the PBCH payload information comprises master information block (MIB) signaling.
17 . A method, comprising:
receiving, from a base station (BS), physical broadcast channel (PBCH) information, the PBCH information comprising a PBCH payload, the PBCH payload including a portion of system timing information and cyclic redundancy check (CRC) information; and
decoding the PBCH information, wherein the PBCH payload is scrambled by a scrambling sequence, wherein scrambling bits of the scrambling sequence are set to 0 for the PBCH payload comprising the portion of the system timing information and excludes the portion of the system timing information from scrambling, wherein the scrambling sequence is based on the portion of the system timing information, wherein the PBCH payload includes the system timing information.
18 . The method of claim 17 , wherein second timing information, not included in the system timing information, is carried on a PBCH demodulation reference signal (DMRS).
19 . The method of claim 18 , wherein the second timing information is 2 or 3 bits of a synchronization signal block index.
20 . The method of claim 17 , wherein other scrambling bits of the scrambling sequence are not set to 0 for other portions of the PBCH payload.