Cell search method and device
View Patent ↗A cell search method is applied to a wireless system for cell search synchronization. Frame signals of the wireless system include a first sub-frame and a second sub-frame. Both of the first and second sub-frames include a first regular timeslot and a down pilot timeslot. It is determined whether a length of an actual synchronization window is smaller than a length of the first synchronization search window that is a sum of a length of the first-sub frame and a length the first regular timeslot and the down pilot of the second sub-frame. When the length of the actual synchronization search window is smaller, at least a part of data carried in the first regular timeslot and the down pilot timeslot of the second sub-frame or the first sub-frame is duplicated to before or after the actual synchronization search window.
1. A cell search method, applied to a wireless communication system to perform cell search synchronization, frame signals of the wireless communication system comprising a first sub-frame and a second sub-frame, both of the first sub-frame and the second sub-frame comprising a first regular timeslot and a down pilot timeslot; the cell search method comprising:
determining whether a length of an actual synchronization search window is smaller than a length of a first synchronization search window, wherein the length of the first synchronization search window is a sum of a length of the first sub-frame and a length of the first regular timeslot and the down pilot timeslot of the second sub-frame; and
when the length of the actual synchronization search window is smaller than the length of the first synchronization search window, duplicating a part of data carried in the first regular timeslot and the down pilot timeslot of the second sub-frame to before the actual synchronization search window, or duplicating a part of data carried in the first regular timeslot and the down pilot timeslot of the first sub-frame to after the actual synchronization search window, such that a sum of a length of the duplicated data and the length of the actual synchronization search window is not smaller than the length of the first synchronization search window.
2. The cell search method according to claim 1 , wherein the length of the first synchronization search window is at least 5.75 ms.
3. The cell search method according to claim 1 , after the step of determining whether the length of the actual synchronization search window is smaller than the length of the first synchronization search window, further comprising:
when the length of the actual synchronization search window is smaller than the length of the first synchronization search window, further determining whether the length of the actual synchronization search window is smaller than the length of the first sub-frame; and
when the length of the actual synchronization search window is not smaller than the length of the first sub-frame, duplicating cell search synchronization data in the second sub-frame that is the first 5 ms of the actual synchronization search window to before the actual synchronization search window, or duplicating cell search synchronization data in the first sub-frame that is the last 5 ms of the actual synchronization search window to after the actual synchronization search window, such that a sum of the length of the duplicated data and the length of the actual synchronization search window is not smaller than the length of the first synchronization search window;
wherein, the cell search synchronization data in the second sub-frame comprises the data carried in the first regular timeslot and the down pilot timeslot of the second sub-frame, and the cell search synchronization data in the first sub-frame comprises the data carried in the regular timeslot and the down pilot timeslot of the first sub-frame.
4. The cell search method according to claim 3 , after the step of determining whether the length of the actual synchronization search window is smaller than the length of the first sub-frame, further comprising:
when the length of the actual synchronization search window is smaller than the length of the first synchronization search window, filling predetermined data to before the actual synchronization search window, or filling the predetermined data to after the actual synchronization search window, such that a sum of a length of the filled predetermined data and the length of the actual synchronization search window is equal to the length of the first synchronization search window;
when the predetermined data is filled to before the actual synchronization search window, duplicating the cell search synchronization data in the actual synchronization search window to before the filled predetermined data, and
when the predetermined data is filled to after the actual synchronization search window, duplicating the cell search synchronization data in the actual synchronization search window to after the filled predetermined data.
5. The cell search method according to claim 4 , wherein the predetermined data is 0 or random numbers.
6. The cell search method according to claim 1 , wherein when the length of the actual synchronization search window is smaller than the length of the first synchronization search window, after the step of duplicating a part of data carried in the first regular timeslot and the down pilot timeslot of the second sub-frame to before the actual synchronization search window, or duplicating a part of data carried in the first regular timeslot and the down pilot timeslot of the first sub-frame to after the actual synchronization search window, the method further comprising:
further determining whether phase transition is present between cell search synchronization data and the actual synchronization search window; and
when the phase transition is present, performing phase compensation on the duplicated cell search synchronization data;
wherein, the cell search synchronization data comprises the data carried in the first regular timeslot and the down pilot timeslot.
7. A cell search device, applied to wireless communication system to perform cell search synchronization, frame signals of the wireless communication comprising a first sub-frame and a second sub-frame, both of the first sub-frame and the second sub-frame comprising a first regular timeslot and a down pilot timeslot; the cell search device comprising:
a determination module and a control module;
wherein, the determination module determines whether a length of an actual synchronization search window is smaller than a length of a first synchronization search window, the length of the first synchronization search window is a sum of a length of the first sub-frame and a length of the first regular timeslot and the down pilot timeslot of the second sub-frame; the determination module further sends a determination result to the control module; and
the control module receives the determination module; when the length of the actual synchronization search window is smaller than the length of the first synchronization search window, the control module duplicates a part of data carried in the first regular timeslot and the down pilot timeslot of the second sub-frame to before the actual synchronization search window, or duplicates a part of data carried in the first regular timeslot and the down pilot timeslot of the first sub-frame to after the actual synchronization search window, such that a sum of a length of the duplicated data and the length of the actual synchronization search window is not smaller than the length of the first synchronization search window.
8. The cell search device according to claim 7 , wherein the length of the first synchronization search window is at least 5.75 ms.
9. The cell search device according to claim 7 , wherein:
when the length of the actual synchronization search window is smaller than the length of the first synchronization search window, the determination module further determines whether the length of the actual synchronization search window is smaller than the length of the first sub-frame;
when the length of the actual synchronization search window is not smaller than the length of the first sub-frame, the control module further duplicates cell search synchronization data in the second sub-frame that is the first 5 ms of the actual synchronization search window to before the actual synchronization search window, or duplicates cell search synchronization data in the first sub-frame that is the last 5 ms of the actual synchronization search window to after the actual synchronization search window, such that a sum of the length of the duplicated data and the length of the actual synchronization search window is not smaller than the length of the first synchronization search window; and
the cell search synchronization data in the second sub-frame comprises the data carried in the first regular timeslot and the down pilot timeslot of the second sub-frame, and the cell search synchronization data in the first sub-frame comprises the data carried in the regular timeslot and the down pilot timeslot of the first sub-frame.
10. The cell search device according to claim 9 , wherein:
when the length of the actual synchronization search window is smaller than the length of the first synchronization search window, the control module further fills predetermined data to before the actual synchronization search window, or fills the predetermined data to after the actual synchronization search window, such that a sum of a length of the filled predetermined data and the length of the actual synchronization search window is equal to the length of the first synchronization search window;
when the predetermined data is filled to before the actual synchronization search window, the control module duplicates the cell search synchronization data of the actual synchronization search window to before the filled predetermined data, such that a sum of the length of the duplicated data, the length of the filled predetermined data and the length of the actual synchronization search data is not smaller than the length of the first synchronization search window; and
when the predetermined data is filled to after the actual synchronization search window, the control module duplicates the cell search synchronization data of the actual synchronization search window to after the filled predetermined data, such that the sum of the length of the duplicated data, the length of the filled predetermined data and the length of the actual synchronization search data is not smaller than the length of the first synchronization search window.
11. The cell search device according to claim 10 , wherein the predetermined data is 0 or random numbers.
12. The cell search device according to claim 7 , wherein:
the determination module further determines whether phase transition is present between cell search synchronization data and the actual synchronization search window;
when the phase transition is present, the control module further performs phase compensation on the duplicated cell search synchronization data; and
the cell search synchronization data comprises the data carried in the first regular timeslot and the down pilot timeslot.