Reference sequence construction for fast cell search
View Patent ↗A method and apparatus for fast cell search based on a chirp reference signal transmission is disclosed herein. A primary synchronization channel (P-SCH) and two secondary synchronization channels (S-SCH 1 and S-SCH 2 ) will be utilized. S- SCH 1 will comprise a reference sequence having a first index value and S-SCH 2 will comprise a reference sequence having a second index value. S-SCH 1 and S- SCH 2 will be scrambled with a first and a second scrambling code, respectively. The second scrambling code will be based on the first index value.
1. A method comprising the steps of:
transmitting a primary synchronization channel (P-SCH) in a frame;
transmitting a first secondary synchronization channel (S-SCH 1 ) in the frame, wherein the S-SCH 1 comprises a first sequence having a first index value and the first sequence is scrambled with a first scrambling code;
transmitting a second secondary synchronization channel (S-SCH 2 ) in the frame, wherein the S-SCH 2 comprises a second sequence having a second index value and the second sequence is scrambled with a second scrambling code that is based on the first index value.
2. The method of claim 1 wherein S-SCH 1 and S-SCH 2 provide cell-specific information such as cell ID.
3. The method of claim 1 wherein the first and the second sequences comprises sequences taken from the group consisting of GCL sequences, Zadoff-Chu sequences, Hadmard sequences, Walsh sequences, or M-sequences.
4. The method of claim 3 wherein a GCL sequence index, Zadoff-Chu sequence index, Hadmard sequence index, Walsh sequence index, or M-sequence index act as a complete cell ID or partial cell ID or other cell-specific information.
5. A method comprising the steps of:
receiving a primary synchronization channel (P-SCH) in a frame;
receiving a first sequence via a first secondary synchronization channel (S-SCH 1 ) in the frame, wherein the first sequence has a first index value and is scrambled with a first scrambling code;
receiving a second sequence via a second secondary synchronization channel (S-SCH 2 ) in the frame, wherein the second sequence has a second index value and is scrambled with a second scrambling code that is based on the first index value; and
utilizing the first and the second secondary synchronization channels for determining cell-specific information.
6. The method of claim 5 wherein the first and the second sequences comprise GCL sequences, Zadoff-Chu sequences, Hadmard sequences, Walsh sequences, or M-sequences.