Secondary synchronization codebook for E-UTRAN
Providing for secondary synchronization encoding utilizing a primary synchronization channel (P-SCH)-related scrambling code is described herein. Scrambled secondary synchronization codes (SSCs) can be assigned to multiple base stations of a radio access network (RAN). By way of example, PSC-based scrambling codes can be created from a plurality of M-sequences generated from a common polynomial expression. Further, an SSC codebook is provided that selects sequence pairs of a sequence matrix for generating SSCs. Selection can be based on transmission characteristics of resulting SSCs, providing reduced interference in planned, semi-planned and/or unplanned mobile deployments.
1. An apparatus for mitigating synchronization code interference in a wireless communication system, comprising:
a processor configured to:
select a pair of sequences;
generate scrambling codes;
wherein the scrambling codes comprise at least a primary synchronization code (PSC)-based scrambling code;
scramble the pair of sequences using the scrambling codes, thereby providing a scrambled pair of sequences;
combine the scrambled pair of sequences via interleaving to form a secondary synchronization code (SSC); and
transmit, by a base station, the SSC to at least one user equipment; and
a memory coupled to the processor.
2. The apparatus of claim 1 , wherein the pair of sequences comprise cyclic shifted variations of a base sequence.
3. The apparatus of claim 1 , wherein the pair of sequences is selected based on at least one projected interference characteristic of the SSC.
4. The apparatus of claim 1 , wherein the PSC-based scrambling code is generated based on sequences that are identified by indices associated with the PSC.
5. The apparatus of claim 4 , wherein the PSC-based scrambling code is based on a cyclic shift of a base sequence.
6. The apparatus of claim 1 , wherein the processor is additionally configured to map the SSC to an over-the-air message.
7. A method for mitigating synchronization code interference in a wireless communication system, comprising:
selecting a pair of sequences;
generating scrambling codes;
wherein the scrambling codes comprise at least a primary synchronization code (PSC)-based scrambling code;
scrambling the pair of sequences using the scrambling codes, thereby providing a scrambled pair of sequences;
combining the scrambled pair of sequences via interleaving to form a secondary synchronization code (SSC); and
transmitting, by a base station, the SSC to at least one user equipment.
8. The method of claim 7 , wherein the pair of sequences comprise cyclic shifted variations of a base sequence.
9. The method of claim 7 , wherein the pair of sequences is selected based on at least one projected interference characteristic of the SSC.
10. The method of claim 7 , wherein the PSC-based scrambling code is generated based on sequences that are identified by indices associated with the PSC.
11. The method of claim 10 , wherein the PSC-based scrambling code is based on a cyclic shift of a base sequence.
12. The method of claim 7 , further comprising mapping the SSC to an over-the-air message.