Operating method of terminal in wireless communication system and terminal for performing the method

1. An operating method of a terminal configured to perform a cell search by using a first memory and a. second memory for buffering input samples, the method comprising:

detecting a first primary synchronization signal (PSS) group from a first input sample group while buffering the first input sample group in the first memory in a first interval;

while buffering a second input sample group in the second memory in a second interval following the first interval, detecting a second PSS group from the second input sample group, and a first secondary synchronization signal (SSS) group corresponding to the first PSS group from the first input sample group; and

while buffering a third input sample group in the first memory in a third interval following the second interval, detecting a third PSS group from the third input sample group, and a second SSS group corresponding to the second PSS group from the second input sample group.

2. The method of claim 1 , wherein

a number of input samples of the first PSS group is set in advance to complete detection of the first SSS group in the second interval, or a number of input samples of the first PSS group used for detecting the first SSS group is limited.

3. The method of claim 1 , wherein detecting the first PSS group further comprises:

computing a correlation degree between input samples of the first input sample group and PSS-based sequences; and

determining the first P 55 group from the first input sample group based on the correlation degree.

4. The method of claim I, wherein detecting the first SSS group further comprises:

selecting any one of input samples included in the first PSS group;

setting an SSS configuration based on information obtained from the selected input sample; and.

detecting an SSS corresponding to the selected input sample based on the set SSS configuration.

5. The method of claim 4 , wherein detecting the SSS further comprises:

generating an SSS-based sequence based on the set SSS configuration;

computing a correlation. degree between the SSS-based sequence and input samples of the first input sample group; and

detecting the SSS based on the correlation degree.

6. The method of claim 1 , wherein

the first SSS group is detected from the first input sample group stored in the first memory.

7. The method of claim 1 , further comprising:

determining a valid cell among a plurality of cells corresponding to the first PSS group and the first SSS group in a buffering interval of the terminal including the first interval through the third interval.

8. The method of claim 7 , wherein determining the valid cell comprises:

generating a comparison value from at least one of a first correlation degree between X input samples included in the first PSS group and a corresponding PSS-based sequence, and a second correlation degree between Y input samples, which are included in the first SSS group and corresponding to the X input samples, and corresponding SSS-based sequences,

wherein X is an integer equal to or greater than 1, and Y is an integer equal to or greater than 1;

comparing the comparison value to a reference value; and

determining whether a cell corresponding to the X input samples and the Y input samples based on the comparison result is the valid cell.

9. The method of claim 8 , wherein generating the comparison value comprises:

generating the comparison value by adding the first correlation degree having a first weight applied thereto to the second correlation degree having a second weight applied thereto.

10. The method of claim 7 , further comprising:

when at least one of the plurality of cells is determined as the valid cell, terminating a buffering operation for the input samples; and

performing a decoding operation for a physical broadcast channel (PBCH) received from the valid cell.

11. The method of claim 10 , further comprising:

when decoding operation for the PBCH is successful, reporting a cell search result to the valid cell and terminating the cell search.

12. An operating method of a cell terminal equipped with a plurality of memories for alternately buffering input samples generated for a cell search operation in a certain buffering interval, the method comprising:

buffering a first input sample group utilized for a first valid cell search operation in a first interval in a first memory; and

buffering a second input sample group utilized for a second valid cell search operation in a second interval following the first interval in a second memory,

wherein the first valid cell search operation is performed by using the first input sample group in a first search interval including the first interval and the second interval.

13. The method of claim 12 , wherein the first valid cell search operation comprises:

detecting a first primary synchronization signal (PSS) group from the first input sample group;

detecting a first secondary synchronization signal (SSS) group corresponding to the first PSS group from the first input sample group; and

determining a valid cell by using the first PSS group and the first SSS group.

14. The method of claim 13 , wherein determining the valid cell further comprises;

determining whether a cell corresponding to X input samples and Y input samples is a valid cell, based on a first correlation degree between the X input samples included in the first PSS group and a corresponding PSS-based sequence, and a second correlation degree between Y input samples, which are included in the first SSS group and corresponding to the X input samples, and a corresponding SSS-based sequence,

wherein X is an integer equal to or greater than 1 , and Y is an integer equal to or greater than 1.

15. The method of claim 12 , further comprising:

buffering a third input sample group utilized for a third valid cell search operation in a third interval following the second interval in the first memory,

wherein the first input sample group is deleted. in the third interval.

16. The method of claim 12 , further comprising:

buffering a third input sample group utilized for a third valid cell search operation in a third interval following the second interval in a third memory,

wherein the first search interval further comprises the third interval.

17. The method of claim 16 , further comprising:

buffering a fourth input sample group utilized for a fourth valid cell search operation in a fourth interval following the third interval in the first memory,

wherein the first input sample group is deleted in the fourth interval.

18. The method of claim 12 , wherein

lengths of the first interval and the second interval vary according to at least one of a communication environment of the terminal, a performance of the terminal, and a workload of the terminal.

19. A terminal, comprising:

a buffer divided into a first memory and a second memory for alternately buffering input samples generated for a cell search operation in a certain buffering interval; and

a baseband processor configured to control a first valid cell search operation from a first input sample group to be buffered in the first memory in a first interval during a first search interval comprising the first interval and a second interval following the first interval,

wherein a second input sample group utilized for a second valid cell search operation in the second interval is buffered in the second memory.

20. The terminal of claim 19 , wherein

the first memory and the second memory of the buffer are physically or virtually divided.