Enhanced cell search and system information acquisition
Embodiments of efeMTC synchronization signals for enhanced cell search and enhanced system information acquisition are described. In some embodiments, an apparatus of a base station (BS) is configured to generate a length-x sequence for an efeMTC synchronization signal, the length-x sequence configured for repetition in frequency domain within 6 physical resource blocks (PRB). In some embodiments, to generate the length-x sequence, the BS may be configured to select any one index of the set of root indices {1, 2, 63}, excluding the root indices 25, 29 and 34, to correspond to a different physical-layer cell identity (PCID). In some embodiments, the BS may be configured to encode RRC signaling to include a System Information Block (SIB) comprising configuration information for transmission of the efeMTC synchronization signal, and transmit the length-x sequence as the efeMTC synchronization signal in frequency resources according to the SIB.
1. An apparatus, comprising:
at least one processor configured to cause a user equipment (UE) to:
receive, from a base station (BS), a configuration for a first synchronization signal additional to a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) in a system information block (SIB), wherein the first synchronization signal utilizes a length-x sequence generated by the BS; and
receive the first synchronization signal, wherein:
the first synchronization signal occurs on consecutive symbols of a subframe, the first synchronization signal is repeated on a plurality of consecutive subframes, and resource elements of the consecutive symbols that correspond to cell-specific reference signals (CRS) remain unchanged.
2. The apparatus of claim 1 , wherein the first synchronization signal is not present in one or more subframe including one or more PSS or SSS.
3. The apparatus of claim 1 , wherein the length-x sequence is initialized by a cell ID.
4. The apparatus of claim 3 , wherein the length-x sequence is further initialized by information related to an update of one or more master information block (MIB) or SIB.
5. The apparatus of claim 1 , wherein the length-x sequence uses an orthogonal cover code.
6. The apparatus of claim 1 , wherein particular subframes are excluded from the plurality of consecutive subframes on which the first synchronization signal is repeated.
7. The apparatus of claim 1 , wherein the length-x sequence includes one or more m-sequence or gold sequence.
8. A wireless device, comprising:
wireless communication circuitry; and
at least one processor coupled to the wireless communication circuitry and configured to cause the wireless device to:
receive, from a base station (BS), a configuration for a first synchronization signal additional to a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) in a system information block (SIB), wherein the first synchronization signal utilizes a length-x sequence generated by the BS; and
receive the first synchronization signal, wherein:
the first synchronization signal occurs on consecutive symbols of a subframe, the first synchronization signal is repeated on a plurality of consecutive subframes, and resource elements of the consecutive symbols that correspond to cell-specific reference signals (CRS) remain unchanged.
9. The wireless device of claim 8 , wherein the length-x sequence is initialized by a cell ID.
10. The wireless device of claim 9 , wherein the length-x sequence is further initialized by information related to an update of one or more master information block (MIB) or SIB.
11. The wireless device of claim 8 , wherein the length-x sequence uses an orthogonal cover code.
12. The wireless device of claim 8 , wherein particular subframes are excluded from the plurality of consecutive subframes on which the first synchronization signal is repeated.
13. The wireless device of claim 8 , wherein the length-x sequence includes one or more m-sequence or gold sequence.
14. An apparatus, comprising:
at least one processor configured to cause a base station (BS) to:
transmit a configuration for a first synchronization signal additional to a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) in a system information block;
generate a length-x sequence for the first synchronization signal,
transmit the first synchronization signal on consecutive symbols of a subframe, wherein the first synchronization signal is repeated on a plurality of consecutive subframes, and wherein resource elements of the consecutive symbols that correspond to cell-specific reference signals (CRS) remain unchanged.
15. The apparatus of claim 14 , wherein the first synchronization signal is dropped in one or more subframe including one or more PSS or SSS.
16. The apparatus of claim 14 , wherein the length-x sequence is initialized by a cell ID.
17. The apparatus of claim 14 , wherein the length-x sequence uses an orthogonal cover code.
18. The apparatus of claim 14 , wherein particular subframes are excluded from the plurality of consecutive subframes on which the first synchronization signal is repeated.
19. The apparatus of claim 14 , wherein the length-x sequence includes one or more m-sequence or gold sequence.
20. The apparatus of claim 14 , wherein the length-x sequence is initialized by information related to an update of one or more of master information block (MIB) or SIB.