Operating method of a terminal in a wireless communication system and terminal for carrying out the method

Abstract

Operating method of a terminal (100) configured to perform a cell search by using a first memory (MEM1) and a second memory (MEM2) for buffering input patterns, the method comprising: detecting a first primary synchronization signal (PSS) group from a first input pattern group (first ISG) while buffering the first input pattern group (first ISG) in the first memory (MEM1) in a first interval (first ITV); while buffering a second input pattern group (second ISG) in the second memory (MEM2) in a second interval (second ITV) following the first interval (first ITV), detecting a second PSS group from the second input pattern group (second ISG) and a first secondary synchronization signal (SSS) group, corresponding to the first PSS group, from the first input pattern group (first ISG); and while buffering a third input pattern group (third ISG) in the first memory (MEM1) in a third interval (third ITV) following the second interval (second ITV), detecting a third PSS group from the third input pattern group (third ISG) and a second SSS group, corresponding to the second PSS group, from the second input pattern group (second ISG).

Description

TECHNICAL FIELD

[0001] Exemplary embodiments of the inventive concept relate to an operating method of a terminal that performs an effective cell search in a wireless communication system and a terminal for the method. DISCUSSION OF THE STATE OF THE ART

[0002] A fifth-generation (5G) (or New Radio (NR)) communication system uses a new wireless access technology. The 5G communication system provides ultra-high-speed data service of several Gbps by using an ultra-wideband with a bandwidth of approximately 100 MHz or more, compared to existing Long-Term Evolution (LTE) and LTE-Advanced(A) (LTE-A) communication systems. However, since it is difficult to secure an ultra-wideband frequency of approximately 100 MHz or more in a frequency band of several 100 MHz or several GHz used in the LTE and LTE-A communication systems, a method of transmitting signals by using a wide-frequency bandwidth existing in a frequency band of approximately 6 GHz or more is under discussion for the 5G communication system.In the 5G communication system, a transmission rate can be increased by using a millimeter wave band such as a band of about 28 GHz or a band of about 60 GHz.

[0003] The publications US 2009 / 0135782 A1, EP 3355629 A1, and DE 112017001486 T5 deal with mobile devices that register with a cell during communication setup. For this purpose, the broadcast signals emitted by each cell are evaluated to detect the respective identifiers, cell parameters, and synchronization sequences. None of these publications discloses a buffer management feature, whereby the sample values ​​are processed across intervals to evaluate the primary and secondary synchronization signals. SUMMARY

[0004] According to an exemplary embodiment, an operating method of a terminal configured to perform a cell search by using a first memory and a second memory for buffering input patterns comprises detecting a first primary synchronization signal (PSS) group from a first input pattern group while buffering the first input pattern group in the first memory in a first interval. The method further comprises detecting a second PSS group from the second input pattern group and a first secondary synchronization signal (SSS) group corresponding to the first PSS group from the first input pattern group while buffering a second input pattern group in the second memory in a second interval following the first interval.The method further comprises, while buffering a third input pattern group in the first memory in a third interval following the second interval, detecting a third PSS group from the third input pattern group and a second SSS group corresponding to the second PSS group from the second input pattern group.

[0005] According to an exemplary embodiment, an operating method of a terminal equipped with a plurality of memories for alternately buffering input patterns generated for a cell search operation in a certain buffer interval comprises buffering a first input pattern group used for a first valid cell search operation in a first interval in a first memory and buffering a second input pattern group used for a second valid cell search operation in a second interval following the first interval in a second memory. The first valid cell search operation is performed by using the first input pattern group in a first search interval including the first interval and the second interval.

[0006] According to an exemplary embodiment, a terminal device comprises a buffer divided into a first memory and a second memory for alternately buffering input patterns generated for a cell search operation in a specific buffer interval, and a baseband processor configured to control a first valid cell search operation from a first input pattern 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. A second input pattern group used for a second valid cell search operation in the second interval is buffered in the second memory. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The above and other features of the inventive concept will become more apparent by describing exemplary embodiments thereof in detail with reference to the accompanying drawings, in which: Fig. 1 is a block diagram of a wireless communication system according to an exemplary embodiment of the inventive concept. Fig. 2 is a diagram illustrating a synchronization signal having a synchronization signal block (SSB) used during a cell search. Fig. 3 is a block diagram of a terminal according to an exemplary embodiment of the inventive concept. Fig. 4 is a diagram for explaining a multi-buffer operation according to an exemplary embodiment of the inventive concept. Fig. 5 is a block diagram of a synchronization signal detector according to an exemplary embodiment of the inventive concept. Fig. 6 is a flowchart illustrating an operating method of a cell searcher according to an exemplary embodiment of the inventive concept. Fig. 7 is a diagram for explaining a detailed operation method of a cell searcher according to an exemplary embodiment of the inventive concept. Fig. 8 is a flowchart illustrating a method of searching for a valid cell performed by a cell searcher according to an exemplary embodiment of the inventive concept. Fig. 9 is a flowchart illustrating operation S230 in Fig. 8 is illustrated in detail. Fig. 10A and Fig. 10B are respectively flowcharts of an operating method of a cell searcher for stably performing a valid cell search operation according to exemplary embodiments of the inventive concept. Fig. 11 and Fig. 12 are respectively flowcharts of a method of searching for a cell performed by a terminal according to exemplary embodiments of the inventive concept. Fig. 13 is a block diagram of a synchronization signal detector according to an exemplary embodiment of the inventive concept. Fig. 14A to 14D are diagrams illustrating lengths of intervals for buffering input pattern groups of a cell searcher according to example embodiments of the inventive concept. Fig. 15 is a diagram for explaining a detailed operation method of a cell searcher according to an exemplary embodiment of the inventive concept. Fig. 16 is a flowchart illustrating a method for searching for a cell of a terminal according to an exemplary embodiment of the inventive concept. Fig. 17 is a block diagram of an electronic device according to an exemplary embodiment of the inventive concept. DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0008] Example embodiments of the inventive concept will be described more fully hereinafter with reference to the accompanying drawings. Like reference numerals may refer to like elements throughout the accompanying drawings. It will be understood that the terms "first," "second," "third," etc., are used herein to distinguish one element from another, and the elements are not limited by these terms. Accordingly, a "first" element in one example embodiment may be described as a "second" element in another example embodiment.

[0009] Fig. 1 is a block diagram of a wireless communication system 1 according to an exemplary embodiment of the inventive concept. Fig. 2 is a diagram illustrating a synchronization signal having a synchronization signal block (SSB) used during a cell search.

[0010] As in Fig. 1, the wireless communication system 1 may include first to third cells 10, 20, and 30 and a terminal 100. The cells 10, 20, and 30 may be, for example, cell towers. For convenience of description, the wireless communication system 1 is illustrated as having only three cells (10, 20, and 30). However, exemplary implementations of the inventive concept are not limited thereto. For example, in exemplary embodiments, the wireless communication system 1 may be implemented to have more or fewer than three cells (10, 20, and 30).

[0011] The terminal device 100 may be connected to the wireless communication system 1 by transmitting and receiving signals to and from the first to third cells 10, 20, and 30. The wireless communication system 1 to which the terminal device 100 is capable of being connected may include a system using radio access technology (RAT), and may include, for example, a wireless communication system using a cellular network such as a fifth-generation (5G) communication system, a Long Term Evolution (LTE) communication system, an LTE-Advanced (A) (LTE-A) communication system, a code division multiple access (CDMA) communication system, a global system for mobile communications (GSM) communication system, or a wireless local area network (WLAN) communication system, or another wireless communication system.Hereinafter, descriptions will be given assuming that the wireless communication system 1 to which the terminal 100 is connected is a 5G communication system. However, exemplary embodiments of the inventive concept are not limited thereto, and exemplary embodiments can be applied to a next-generation wireless communication system.

[0012] In a 5G communication system, due to a beamforming technique for increasing the arrival distance of a radio wave, it is necessary, in a cell search operation of the terminal device, not only to search for a cell capable of providing good communication service, but also to search for a transmission beam that matches a reception beam of the terminal device among a plurality of transmission beams formed by the cell. Therefore, for this purpose, the number of input patterns of synchronization signals to be buffered by the terminal device increases dramatically. As a result, there is a possibility that available memory space for data processing operations other than the cell search operation of the terminal device may be limited, and thus, the overall performance of the terminal device may be reduced.Exemplary embodiments of the inventive concept are directed to using the available storage space in a more efficient manner, as described in detail below.

[0013] A wireless communication network of the wireless communication system 1 can support communication of a plurality of wireless communication devices including the data terminal 100 by sharing available network resources. For example, in the wireless communication network, information can be transmitted using various multiple connection methods such as CDMA, frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single-carrier frequency division multiple access (SC-FDMA), OFDM-FDMA, OFDM-TDMA, and OFDM-CDMA.

[0014] The first to third cells (10, 20, and 30) may generally be referred to as fixed stations in communication with the terminal 100 and / or other cells, and they may exchange data and control information by communicating with the terminal 100 and other cells. For example, each of the first to third cells 10, 20, and 30 may be referred to as a base station, a Node B, an Evolved Node B (eNB), a Next Generation Node B (gNB), a sector, a site, a Base Transceiver System (BTS), an Access Point (AP), a Relay Node, a Remote Radio Head (RRH), a Radio Unit (RU), a Small Cell, etc.In the present description, the cell or base station can be interpreted in a generic sense to denote an area or function covered by a base station controller (BSC) in CDMA, the Node-B in WCDMA, an eNode B (eNB) in LTE, or a sector, etc., and can cover all different coverage areas such as megacell, macrocell, microcell, picocell, femtocell, the relay node, RRH, RU, and a small cell communication area.

[0015] The terminal 100 may be fixed or mobile user equipment (UE) and may be referred to as any device capable of communicating with the cell(s) to send and receive data to and from the cell(s) and / or control information. For example, the terminal 100 may be referred to as a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a smartphone, a wireless device, a handheld device, etc.

[0016] Referring to Fig. 1, the first to third cells 10, 20, and 30 may be connected to the terminal 100 via a wireless channel and may provide various communication services. The first to third cells 10, 20, and 30 may serve all user traffic via a shared channel and may perform scheduling by collecting status information, such as a buffer status, an available transmission power status, and a channel status of the terminal 100. The wireless communication system 1 may support a beamforming technology by using OFDM as the radio access technology. In addition, the wireless communication system 1 may support an adaptive modulation and coding (AMC) method for determining a modulation scheme and a channel coding rate according to the channel status of the terminal 100.

[0017] The wireless communication system 1 can transmit and receive signals by using a wide frequency band existing in a frequency band of approximately 6 GHz or more. For example, in the wireless communication system 1, a data transmission rate can be increased by using a millimeter wave band such as a band of approximately 28 GHz or a band of approximately 60 GHz. In this case, the millimeter wave band can support directional beam-based transmission, which is created by using multiple antennas to ensure coverage, because an amount of signal attenuation with respect to distance is relatively large. The wireless communication system 1 can perform a beam sweep operation for the directional beam-based transmission.

[0018] Beam sweeping may be a process of determining a transmission beam and a reception beam having orientation directions that are modulated with each other by sequentially or randomly sweeping directed beams having a specific structure by the terminal 100 and the first to third cells 10, 20, and 30. For example, a transmission beam structure and a reception beam structure having the orientation directions that are aligned with each other may be determined as a pair of transmission / reception beam structures. The beam structure may be a shape of a beam determined by a width and an orientation direction thereof.Hereinafter, an exemplary embodiment will be described mainly for a case where the terminal 100 performs the cell search, and it is assumed that the first to third cells (10, 20, and 30) transmit synchronization signals, each having the SSB used for the cell search, to the terminal 100 via a plurality of transmission beams having different beam structures from each other. As an example, the first cell 10 may transmit synchronization signals, each having SSBs used for the cell search, to the terminal 100 via first to eighth transmission beams TX_B1 to TX_B8. However, it should be appreciated that. Fig. 1 is only one example for convenience of understanding that exemplary embodiments are not limited thereto and that various cases may occur according to a communication environment or a communication situation of the wireless communication system 1.

[0019] With reference to the Fig. 1 and Fig. 2, for example, the first cell 10 may transmit synchronization signals including any one of the first to eighth SSBs SSB1 to SSB8 to the terminal 100 via the first to eighth transmission beams TX_B1 to TX_B8, respectively. For example, the first cell 10 may transmit a signal including the first SSB SSB1 to the terminal 100 via the first transmission beam TX_B1, a signal including the second SSB SSB2 to the terminal 100 via the second transmission beam TX_B2, etc. In this way, the first cell 10 may transmit the first to eighth SSBs SSB1 to SSB8 to the terminal 100 via the first to eighth transmission beams TX_B1 to TX_B8, respectively, and the terminal 100 may search for the first cell 10 by using any one of the first to eighth SSBs SSB1 to SSB8.

[0020] As in Fig. 2, the SSB may include a primary synchronization signal PSS, a secondary synchronization signal SSS, and a physical transmission signal PBCH. In an exemplary embodiment, the SSB may include four symbols, and the primary synchronization signal PSS, the secondary synchronization signal SSS, and the physical transmission signal PBCH may be placed at locations corresponding to particular resource blocks RB in a frequency axis direction. Additionally, a resource block RB may include 12 consecutive subcarriers. As an example, the primary synchronization signal PSS corresponding to a first symbol may be transmitted to the terminal 100 via 127 subcarriers.

[0021] In an exemplary embodiment, there may be two SSBs in a slot, and the first cell 10 may transmit one SSB burst set to the terminal 100 in a particular SSB burst set period T SSBFor example, assuming that the wireless communication system 1 is New Radio (NR) with a subcarrier spacing of approximately 15 kHz, the first cell 10 may transmit the SSB burst set comprising the first to eighth SSBs SSB1 to SSB8 to the terminal 100 during the SSB burst set period T SSB In this case, a slot length can be approximately 1 ms, and the SSB burst set period T SSB may be approximately 20 ms. However, exemplary embodiments are not limited thereto, and the number of SSBs included in the SSB burst set, the SSB burst set period T SSB and the length of a slot may vary according to, for example, a size of the subcarrier spacing, a synchronization signal period set in the first cell 10, a time interval allocated for cell search, etc.

[0022] For example, the first to eighth SSBs SSB1 to SSB8 may be transmitted to the terminal 100 via the first to eighth transmission beams TX_B1 to TX_B8 of the first cell 10, respectively, and in this way, the second cell 20 and the third cell 30 may also transmit synchronization signals including the SSBs used for searching for the second cell 20 and the third cell 30 by the terminal 100 to the terminal 100 via the plurality of transmission beams.

[0023] The terminal 100 according to an exemplary embodiment of the inventive concept may receive synchronization signals from the first to third cells 10, 20, and 30, generate a plurality of input patterns by sampling synchronization signals, and perform a valid cell search operation per input pattern group by dividing the input patterns into specific input pattern groups. The plurality of input patterns may include a plurality of primary synchronization signals PSS, a plurality of secondary synchronization signals SSS, and a plurality of physical transmission channels PBCH received from each of the first to third cells 10, 20, and 30. The terminal 100 may perform a multi-buffer operation on the plurality of input patterns by using a plurality of memories of the terminal 100 to perform the valid cell search operation per the input pattern group.Details of the valid cell search operation per the input pattern group and the multi-buffer operations on the input patterns of the terminal 100 are described below.

[0024] Fig. 3 is a block diagram illustrating the terminal 100 in detail according to an exemplary embodiment of the inventive concept.

[0025] Referring to Fig. 3, the terminal device 100 may include a plurality of antennas 110, a front-end circuit 120, a transceiver 130, and a controller 140. The plurality of antennas 110 may be connected to the front-end circuit 120 and may transmit signals provided by the front-end circuit 120 to other wireless communication devices (terminals or cells) or provide signals received from the other wireless communication devices to the front-end circuit 120. In exemplary embodiments, the terminal device 100 may support phased array, multi-input and multi-output (MIMO), etc., by using the plurality of antennas 110. The front-end circuit 120 may include an antenna tuner, and the antenna tuner may be connected to the plurality of antennas 110 to adjust the impedance of the plurality of antennas 110.

[0026] The transceiver 130 may include a receiver 131, a transmitter 132, and a switch 133. The receiver 131 may generate a baseband receive signal by processing a radio frequency (RF) receive signal received by the switch 133. As an example, the receiver 131 may include a filter, a mixer, a low-noise amplifier, etc. The receiver 131 may process RF band synchronization signals received by the switch 133 to generate baseband synchronization signals, and the baseband synchronization signals may be provided to the controller 140. The transmitter 132 may generate an RF transmit signal by processing a baseband transmit signal received by the controller 140. The transmitter 132 may include, for example, a filter, a mixer, a power amplifier, etc.

[0027] The controller 140 may include a cell searcher 142, and the cell searcher 142 may include a synchronization signal (SS) detector 142a and a buffer 142b. Components included in the controller 140 may be implemented as a dedicated hardware block designed using logic synthesis, etc., or may be implemented as at least one processor and a processing unit including a software block executed by the at least one processor, and may be implemented as a combination of dedicated hardware blocks and processing units. In the present description, the controller 140 may be referred to as a device for efficiently performing the cell search.

[0028] The cell searcher 142 can perform the cell search operation and can allow the terminal device 100 to connect to the wireless communication system 1 via a searched cell and perform wireless communication. The SS detector 142a can perform the valid cell search operation per input pattern group by dividing a plurality of input patterns generated by sampling the baseband synchronization signals into input pattern group units. The SS detector 142a, when performing the valid cell search operation, can perform multi-buffering for a plurality of input patterns by using a plurality of memories MEM of the buffer 142b.

[0029] For example, the plurality of memories MEM of the buffer 142b may alternately perform buffering of the input patterns in the input pattern group units. For example, the input pattern groups having odd numbers of turns may be buffered in a first memory of the plurality of memories MEM, and the input pattern groups having even numbers of turns may be buffered in a second memory of the plurality of memories MEM. This will be further described with reference to Fig. 4. The plurality of memories MEM of the buffer 142b may be physically separated or virtually divided by address management. The valid cell search operation may be referred to as a series of operations for detecting a primary synchronization signal PSS group and a secondary synchronization signal SSS group by using the input patterns included in an input pattern group, and determining the valid cell by using the detected primary synchronization signal PSS group and secondary synchronization signal SSS group.

[0030] The terminal device 100 according to an exemplary embodiment of the inventive concept can efficiently use memories by performing multiple buffers of input patterns in input pattern group units by using a plurality of memories, and can perform prompt cell search by performing one valid cell search operation per input pattern group.

[0031] Fig. 4 is a diagram for explaining a multi-buffer operation according to an exemplary embodiment of the inventive concept. Fig. 5 is a block diagram of the SS detector 142a according to an exemplary embodiment of the inventive concept. In Fig. 4, a buffer for buffering the input patterns of the terminal 100 is described, assuming that the buffer includes the first memory and the second memory.

[0032] Referring to Fig. 4, in a specific buffer interval BF_ITV, the plurality of input patterns can be divided into the input pattern groups and alternately buffered in the first memory and the second memory. The buffer interval BF_ITV can be set to coincide with the SSB burst setting period T SSB the Fig. 2. In addition, each length of the first to n-th intervals (first ITV to n-th ITV) may be determined according to the number of input patterns included in the first to n-th input pattern groups (first ISG to n-th ISG). The plurality of input patterns may be divided into the first to n-th input pattern groups (first ISG to n-th ISG) and alternately buffered in the first memory and the second memory in the first to n-th intervals (first ITV to n-th ITV).

[0033] For example, the first input pattern group (first ISG) may be buffered in the first memory in the first interval (first ITV), the second input pattern group (second ISG) may be buffered in the second memory in the second interval (second ITV), and the third input pattern group (third ISG) may be buffered in the first memory in the third interval (third ITV). In an exemplary embodiment, the first memory and the second memory may have sufficient capacity to buffer an input pattern group, and a previously stored input pattern group may be deleted when a new input pattern group is to be buffered. Although Fig. 4 illustrates an exemplary embodiment in which the buffer interval BF_ITV is divided into the first to n-th intervals first ITV to n-th ITV, which have the same length. Example embodiments are not limited thereto. For example, in example embodiments, the lengths of the first to n-th intervals first ITV to n-th ITV may vary according to the environment, performance, workload, etc., and detailed example embodiments thereof will be described with reference to FIG. Fig. 14A to 14D.

[0034] Referring to Fig. 5, the SS detector 142a may include a PSS detector 142a_1, an SSS detector 142a_2, and a timing controller 142a_3. The PSS detector 142_1 may perform a PSS detection operation in units of input pattern groups. The PSS detector 142_1 may calculate a correlation degree between the input patterns of the input pattern group and the PSS-based sequences, and calculate the PSS group from the input pattern group based on the calculated correlation result. The PSS group may indicate a unit having input patterns corresponding to a good candidate PSS for cell search from a specific input pattern group.For example, the PSS detector 142a_1 may calculate the degree of correlation between a target input pattern and a corresponding PSS-based sequence, and may determine the target input pattern as the PSS group if the calculated correlation result is equal to or greater than a first reference value. The PSS detector 142a_1 may perform an operation for determining the PSS group in parallel with an operation for buffering the input pattern group in a specific memory.

[0035] The SSS detector 142a_2 may select any one of the input patterns of the PSS group detected by the PSS detector 142a_1, set an SSS configuration based on information obtained from the selected input pattern, and determine the SSS group by performing at least one operation for detecting the SSS corresponding to the selected input pattern based on the set SSS configuration. The SSS group may indicate an entity having input patterns corresponding to a good candidate SSS for cell search from a specific input pattern group. The information obtained from the selected input pattern may include a specific timing (e.g., 5 ms timing) of a cell corresponding to the selected input pattern, a primary identification number (PID) of the cell, a location of the SSS, etc.

[0036] The SSS detector 142a_2 may set an SSS configuration based on the information obtained from the selected input pattern and generate an SSS-based sequence based on the set SSS configuration. The SSS detector 142a_2 may calculate a correlation degree between the generated SSS-based sequence and the input patterns of the input pattern group and determine the SSS group from the input pattern group based on the calculated correlation result. For example, the SSS detector 142a_2 may calculate the correlation degree between a target input pattern and a corresponding SSS-based sequence and may determine the target input pattern as the SSS group if the calculated correlation result is equal to or greater than a second reference value.The SSS detector 142a_2 may perform an operation for determining the SSS group by using an input pattern group stored in a specific memory.

[0037] The time selection controller 142a_3 may select operation times of the PSS detector 142a_1 and the SSS detector 142a_3 according to a buffer state of the buffer 142b (see Fig. 3) of the terminal 100. In one example, the timing controller 142a_3 may provide a first timing control signal TM_C1 to the PSS detector 142a_1 and may control the PSS detector 142a_1 to perform the PSS detection operation by using the pattern group while the input pattern group is stored in the memory of the buffer 142b (see Fig. 3) is buffered. In addition, after completing the SSS configuration, based on the information obtained from the PSS group by providing a second timing control signal TM_C2 to the SSS detector 142a_2, the timing controller 142a_3 may control the SSS detector 142a_2 to perform the SSS detection operation by using the input pattern group stored in the memory.

[0038] Furthermore, the timing controller 142a_3 may control the memory to complete the SSS acquisition operation (or a valid cell search operation using the input pattern group) for the input pattern group before the memory storing the input pattern group buffers the new input pattern group. In an exemplary embodiment, the timing controller 142a_3 may preset the number of input patterns (or PSS) of the PSS group or limit the number of input patterns (or PSS) of the PSS group used to acquire the SSS group. This will be further described with reference to Fig. 7 described.

[0039] Fig. 6 is a flowchart illustrating an operating method of the cell searcher 142 according to an exemplary embodiment of the inventive concept. Fig. 6 is with reference to the configuration of the terminal 100 of the Fig. 3. In addition, it is assumed that "N" is the number of input patterns included in an input pattern group, "h" is the ordinal number of the input pattern group, "i" is the ordinal number of the input pattern included in the input pattern group, "K" is the ordinal number of the input pattern determined based on all input patterns, and "M" is the number of all input patterns.

[0040] Referring to Fig. 6, the cell searcher 142 may receive an i-th input pattern (S100) and determine whether the ordinal number "h" of the input pattern group including the i-th input pattern is odd (S101). If a result of the operation S101 is "YES," the i-th input pattern may be buffered in the first memory of the buffer 142b (S102). Otherwise, if the result of the operation S101 is "NO," the i-th input pattern may be buffered in the second memory of the buffer 142b (S103). The SS detector 142a may perform the PSS detection operation by using the i-th input pattern buffered in either the first memory or the second memory (S104).

[0041] The cell searcher 142 may determine whether "i" is equal to "N-1" or "K" is equal to "M" (S105). If a result of the operation S105 is "NO", "i" may be incremented (S106), and operations S100 to S105 may be performed again. As an example, the cell searcher 142 may acquire the PSS group from the first input pattern group by buffering the input patterns included in the first input pattern group in the first memory through operations S100 to S106. If a result of the operation S105 is "YES", "h" may be incremented (S107), and operations S100 to S105 may be performed again. As an example, after the buffering operation for the first input pattern group is completed, the cell searcher 142 may perform an operation for buffering the second input pattern group in the second memory.

[0042] If the result of operation S105 is "YES," the SS detector 142a may perform the SSS detection operation by using the PSS group detected from a specific input pattern group by operation S104 performed multiple times (S108). In one example, the SS detector 142a may set the SSS configuration by using the PSS group detected from the first input pattern group in an interval in which the buffer operation is performed for the second input pattern group, and may detect the SSS group from the first input pattern group by using the set SSS configuration. The cell searcher 142 may determine a valid cell by using the PSS group and the SSS group detected from a specific input pattern group (S109).As an example, the cell searcher 142 may determine a valid cell by using the PSS group and the SSS group acquired from the first input pattern group (S109). The cell searcher 142 may determine whether "h" is equal to "M / N" (or the total number of input pattern groups) (S110). If a result of operation S110 is "NO," operations S108 and S109 may be performed for the other input pattern groups. Otherwise, if the result of operation S110 is "YES," execution of the valid cell search operation using the input patterns may be terminated.

[0043] Fig. 7 is a diagram for explaining a detailed operation method of the cell searcher 142 according to an exemplary embodiment of the inventive concept. Fig. 7, it is assumed that the valid cell search operation is performed based on a double buffer operation using the first memory MEM1 and the second memory MEM2.

[0044] Referring to Fig. 7, the cell searcher 142 may generate a first PSS group detection result PSS_R1 by performing a first PSS group detection operation first PSS_D from the first input pattern group first ISG while buffering the first input pattern group first ISG in a first memory MEM1 in the first interval first ITV corresponding to a time between a time "t1a" and a time "t2a". As described above, the cell searcher 142 may generate the first PSS group detection result PSS_R1 by calculating the degree of correlation between the input patterns included in the first input pattern group first ISG and the corresponding PSS-based sequences and determining an input pattern (or PSS) that matches a condition that the correlation result is equal to or greater than the first reference value as the first PSS group.

[0045] The cell searcher 142 may generate a second PSS group detection result PSS_R2 by performing a second PSS group detection operation second PSS_D from the second input pattern group second ISG while buffering the second input pattern group second ISG in a second memory MEM2 in the second interval second ITV corresponding to a time between the time "t2a" and a time "t3a". In addition, the cell searcher 142 may set the SSS configuration for performing the first SSS group detection operation first SSS_D based on the first PSS group detection result PSS_R1 in a certain interval F1 from a time identical or similar to the time "t2a". The cell searcher 142 may perform a first SSS group detection operation first SSS_D in the second interval second ITV based on the set SSS configuration and generate a first SSS group detection result SSR_R1 until a time “t3a”.As described above, the cell searcher 142 can generate the first SSS group detection result SSS_R1 by calculating the degree of correlation between the input patterns included in the first input pattern group (first ISG) and the corresponding SSS-based sequences, and determining an input pattern (or SSS) that matches a condition that the correlation result is equal to or greater than the second reference value as the first SSS group. Thereafter, the cell searcher 142 can determine a valid cell by using at least one of the first PSS group detection result PSS_R1 and the first SSS group detection result SSS_R1 during a time interval between the time "t3a" and the time "t4a."

[0046] In this way, the cell searcher 142 may perform a first valid cell search operation including the first PSS group detection operation first PSS_D and the first SSS group detection operation first SSS_D during a first search interval VCD_ITV. The first search interval VCD_ITV may include the first interval first ITV and the second interval second ITV. Considering the time required to determine the valid cell, the cell searcher 142 may control the first SSS group detection operation first SSS_D to be completed at time "t3a". The cell searcher 142 may determine the valid cell by using at least one of the first PSS group detection result PSS_R1 and the first SSS group detection result SSS_R1. The cell searcher 142 may perform a decoding operation on the physical transmission channel PBCH of the particular valid cell, as further described with reference to the Fig. 11 and Fig. 12 is described.

[0047] The cell searcher 142 may generate a third PSS group detection result PSS_R3 by performing a third PSS group detection operation third PSS_D from the third input pattern group third ISG while buffering the third input pattern group third ISG in the first memory MEM1 in the third interval third ITV corresponding to a time between the time "t4a" and a time "t5a". In the third interval third ITV, the first input pattern group first ISG previously stored in the first memory MEM1 may be deleted. In addition, the cell searcher 142 may set the SSS configuration for performing the second SSS group detection operation second SSS_D based on the second PSS group detection result PSS_R2 in a certain interval F2 from a time identical or similar to the time "t4a".The cell searcher 142 may perform a second SSS group detection operation (second SSS_D) in the third interval (third ITV) based on the set SSS configuration and generate a second SSS group detection result (SSS_R2) until time "t5a." Thereafter, the cell searcher 142 may determine a valid cell by using at least one of the second PSS group detection result (PSS_R2) and the second SSS group detection result (SSS_R2) during a time interval between time "t5a" and time "t6a."

[0048] In this manner, the cell searcher 142 can perform the valid cell search operation for each input pattern group and perform an alternating buffer operation in the first memory MEM1 and the second memory MEM2 for each input pattern group.

[0049] Fig. Fig. 8 is a flowchart illustrating a method for searching for the valid cell of a cell searcher, which is performed by a cell searcher according to an exemplary embodiment of the inventive concept. For example, the method of Fig. 8 by the cell finder 142. Fig. Figure 8 illustrates an operation of the cell searcher in any of the consecutive first to third intervals in the buffer interval, and it should be appreciated that the operation of the cell searcher shown in Fig. 8, can be applied to other intervals in the buffer interval.

[0050] Referring to Fig. 8, the cell searcher may buffer the first input pattern group used for the first valid cell search operation in the first interval in the first memory (S200). The cell searcher may buffer the second input pattern group used for the second valid cell search operation in the second interval following the first interval in the second memory (S210). The cell searcher may buffer the third input pattern group used for the third valid cell search operation in the third interval following the second interval in the first memory (S220). The cell searcher may perform the first valid cell search operation in the first acquisition interval comprising the first interval and the second interval (S230).As described above, the first valid cell search operation may include the first PSS group detection operation using the first input pattern group, the first SSS group detection operation, and the valid cell search operation using the first PSS group and the first SSS group. The cell searcher may perform the second valid cell search operation during the second detection interval including the second interval and the third interval (S240). As described above, the second valid cell search operation may include the second PSS group detection operation using the second input pattern group, the second SSS group detection operation, and the valid cell search operation using the second PSS group and the second SSS group.

[0051] Fig. 9 is a flowchart showing operation S230 in Fig. 8 is illustrated in detail.

[0052] Referring to Fig. 9, the cell searcher may detect the first PSS group from the first input pattern group (S232). The cell searcher may generate the PSS-based sequences and calculate the correlation degree between the input patterns included in the first input pattern group and the PSS-based sequences. The cell searcher may determine input patterns having the correlation degree equal to or greater than the first reference value as the first PSS group based on the correlation degree calculation result.

[0053] The cell searcher may acquire the first SSS group corresponding to the first PSS group from an input pattern group (S234). The cell searcher may set the SSS configuration by obtaining specific information from the input patterns included in the first PSS group and may generate the SSS reference sequences based on the set SSS configuration. The cell searcher may calculate the correlation degree between the input patterns included in the first input pattern group and the SSS-based sequences. The cell searcher may determine input patterns having the correlation degree equal to or greater than the second reference value as the first SSS group based on the correlation degree calculation result. In an exemplary embodiment, the first reference value and the second reference value may be identical to or different from each other.

[0054] The cell searcher may determine the valid cell by using at least one of the first PSS group and the first SSS group (S236). The cell searcher may generate a comparison value from at least one of a first degree of correlation between X (where X is an integer equal to or greater than 1) input patterns included in the first PSS group and the corresponding PSS-based sequences, and a second degree of correlation between Y (where Y is an integer equal to or greater than 1) input patterns included in the first SSS group corresponding to the X input patterns and the corresponding SSS-based sequences. The cell searcher may compare the generated comparison value with the third reference value and may determine whether a cell corresponding to the X input patterns and the Y input patterns is a valid cell based on the comparison result.For example, the cell searcher may determine that the cell is a valid cell if the generated comparison value is equal to or greater than the third reference value. In an exemplary embodiment, the cell searcher may generate comparison values ​​by applying a first weight to the first correlation degree and a second weight to the second correlation degree, respectively, and adding two generated comparison values. The first weight and the second weight may be values ​​determined by a plurality of simulation results for an accurate valid cell search, and the first weight and the second weight may be preset in the cell searcher.

[0055] In this way, the cell searcher can perform the valid cell search operation by using the other input pattern groups.

[0056] The Fig. 10A and Fig. 10B are respectively flowcharts of an operating method of a cell searcher (e.g., cell searcher 142) for stably performing a valid cell search operation according to exemplary embodiments of the inventive concept. As an example, since the first input pattern group first ISG in the third interval third ITV in Fig. 7 is deleted, the cell searcher must complete the first valid cell search operation using the first input pattern group (first ISG) before the third interval (third ITV) starts, that is, within the first search interval (VCD_ITV). For example, the cell searcher may employ a method described below such that the valid cell search operation can be completed within the specified search interval before the input pattern group used for the valid cell search operation is deleted by multibuffering.

[0057] Referring to Fig. 10A can, if the cell finder performs operation S232 (see Fig. 9), the cell searcher determines the candidate input patterns that can be separated from the first input pattern group into the first PSS group (S232a). The candidate input patterns may have the correlation degrees between the respective PSS-based sequences equal to or greater than the first reference value. The number of input patterns included in the first PSS group may be set in advance, or the number of input patterns may be set by considering at least one of the performance of the terminal device, a communication environment of the terminal device, and a workload of the terminal device. The cell searcher may determine input patterns included in the first PSS group from the candidate input patterns to match or adjust the number of set input patterns (S232b).For example, the cell searcher may increase the number of input patterns of the first PSS group if it is determined that the first valid cell search operation can be reasonably performed in the first search interval, and may decrease the number of input patterns of the first PSS group if it is determined that the first valid cell search operation cannot be reasonably performed in the first search interval. Additionally, in an exemplary embodiment, when performing operation S232b, the cell searcher may determine the first PSS group from the candidate input patterns, considering at least one of the magnitude of the correlation degree, frequency intervals between the candidate input patterns, etc. Thereafter, the cell searcher may perform operation S234 (see ). Fig. 9).

[0058] Referring to Fig. 10B can, if the cell finder performs operation S234 (see Fig. 9) the cell searcher selects at least one input pattern used for detecting the first SSS group from the input patterns of the first PSS group (S234a). For example, the cell searcher may select at least one input pattern used for the first SSS group detection from the input patterns of the first PSS group after considering at least one of the performance of the terminal device, the communication environment of the terminal device, the workload of the terminal device, etc., such that the first valid cell search operation can be completed within the first search interval even if the first PSS group has been determined.In one example, if it is determined that the first valid cell search operation can be performed in the first search interval, the cell searcher may increase the number of input patterns of the first PSS group used for the first SSS group detection operation, and if it is determined that the first valid cell search operation cannot be performed in the first search interval, the cell searcher may decrease the number of input patterns of the first PSS group used for the first SSS group detection operation. The cell searcher may detect the first SSS group by using the selected at least one input pattern of the first PSS group (S234b). Thereafter, the cell searcher may perform operation S236 (see . Fig. 9).

[0059] The Fig. 11 and Fig. 12 are respectively flowcharts of a method for searching for a cell of a terminal according to exemplary embodiments of the inventive concept.

[0060] Referring to Fig. 11, the cell searcher may determine the valid cell(s) by using all of the double-buffered input patterns in a specific buffer interval (S300). For example, the cell searcher may perform a plurality of valid cell search operations using all of the input pattern groups and may determine the valid cell(s) as a result of performing the plurality of valid cell search operations. The cell searcher may perform remaining cell search operations based on the valid cell(s) (S310). For example, the cell searcher may decode the physical transmission channel PBCH received from the determined valid cell, report the decoding result to the valid cell if the decoding result for the physical transmission channel PBCH is successful, and perform wireless communication with the valid cell.However, if the decoding result for the physical transmission channel PBCH fails, the cell searcher can decode the physical transmission channel PBCH received from the other valid cell.

[0061] Referring to Fig. 12, the cell searcher may determine the valid cell by performing the valid cell search operation for each input pattern group using doubly buffered input patterns (S300'). The cell searcher may determine whether the valid cell has been determined in L (where L is an integer equal to or greater than 1) effective cell search operations while performing the valid cell search operation (S310'). The cell searcher may perform operation S300' if operation S310' is "NO" and may terminate the buffer operation for the input patterns that have not yet been buffered if operation S310' is "YES" (S320'). Alternatively, in Fig. 12, since the buffer operation is terminated when the valid cell is determined, the effective cell search operation for the input pattern group which is not buffered thereafter may be omitted. Therefore, a criterion for determining a valid cell in operation S300' may be stricter than that in operation S300 in Fig. 11 to ensure a high probability of cell search success. The cell searcher may perform remaining cell search operations based on the determined valid cell(s) determined in the L valid cell search operations (S330'). For example, the cell searcher may decode the physical transmission channel PBCH received from the determined valid cell, report the decoding result to the valid cell if the decoding result for the physical transmission channel PBCH is successful, and perform wireless communication with the valid cell. However, if the decoding result for the physical transmission channel PBCH fails, the cell searcher may re-receive the synchronization signals from the cells and perform the cell search operation again.

[0062] Fig. 13 is a block diagram of an SS detector 142a' according to an exemplary embodiment of the inventive concept.

[0063] Referring to Fig. 13, the SS detector 142a' may include a PSS detector 142a_1', an SSS detector 142a_2', and a time selection controller 142a_3'. Hereinafter, for convenience of explanation, a further description of the configuration, elements, and technical aspects of the SS detector 142a may be given, which may be described with reference to Fig. 5, which is the same for the SS detector 142a' of the Fig. 13 are omitted. The timing controller 142a_3' may include an interval adjuster ITV_AD and a lookup table LUT. The interval adjuster ITV_AD according to an exemplary embodiment may adjust the number of input patterns included in the input pattern group based on adjustment information AD_I and may adjust the length of the interval in which the input pattern group is buffered in a specific memory. The adjustment information AD_I may include information about the communication environment of the terminal device, the performance of the terminal device, the workload of the terminal device, etc. The lookup table LUT may include information about the adjustment information AD_I of different values, the number of input patterns included in the input pattern group adjusted to each of the different values, and the length of the interval.The interval adjuster ITV_AD can acquire information about the number of input patterns corresponding to the received adjustment information AD_I and the length of the section by referring to the lookup table LUT, and can adjust the number of input patterns and the length of the section based on the acquired information.

[0064] The time selection controller 142a_3', which is Fig. 13, but is not limited thereto. For example, in exemplary embodiments, the number of input patterns of the input pattern group, the length of the interval at which the input pattern group is buffered, etc., may be adjusted variously, taking into account different states of the terminal device.

[0065] The Fig. 14A to 14D are diagrams illustrating lengths of intervals for buffering input pattern groups of a cell searcher (e.g., cell searcher 142) according to exemplary embodiments of the inventive concept, respectively. Fig. 14A to 14D illustrate exemplary embodiments of intervals included in a buffer interval part BF_ITV part of the same length.

[0066] Referring to Fig. 14A the buffer interval part BF_ITV part the first to fifth intervals have the first ITV to the fifth ITV. The first to fifth intervals have the same length, and accordingly, the number of input patterns included in each of the first to fifth input pattern groups has the same length.

[0067] Referring to Fig. 14B the buffer interval part BF_ITV parta first to third interval first ITV' to third ITV'. The first to third interval first ITV' to third ITV' may have the same length and the length thereof may be greater than that of the first to fifth interval first ITV to fifth ITV in Fig. 14A. However, the number of input patterns included in each of the first to third input pattern groups first ISG' to third ISG' may be the same, and the number thereof may be larger than that of the input patterns included in each of the first to fifth input pattern groups first ISG to fifth ISG in Fig. 14A is included.

[0068] Referring to Fig. 14C the buffer interval part BF_ITV parta first to fourth interval first ITV'' to fourth ITV''. The first and third intervals first ITV'' and third ITV'' may have the same length, and accordingly, the number of input patterns included in each of the first and third intervals first ITV'' and third ISG'' may be the same. In addition, the second and fourth intervals second ITV'' and fourth ITV'' may have the same length, and accordingly, the number of input patterns included in each of the second and fourth intervals second ITV'' and fourth ITV'' may be the same. Alternatively, the length of the first and third intervals first ITV'' and third ITV'' may be different from that of the second and fourth intervals second ITV'' and fourth ITV''.Accordingly, the number of input patterns of the first and third input pattern groups first ISG'' and third ISG'' may be different from the number of input patterns of the second and fourth input pattern groups second ISG'' and fourth ISG''. The length of the first and third intervals first ITV'' and third ITV'' may be less than the length of the second and fourth intervals second ITV'' and fourth ITV'', and the number of input patterns of the first and third input pattern groups first ISG'' and third ISG'' may be less than the number of input patterns of the second and fourth input pattern groups second ISG'' and fourth ISG''.

[0069] Referring to Fig. 14D the buffer interval part BF_ITV parta first to fourth interval first ITV''' to fourth ITV'''. The lengths of the first to fourth interval first ITV''' to fourth ITV''' may be different from each other and accordingly the number of input patterns included in each of the first to fourth input pattern groups first ISG''' to fourth ISG''' may be different from each other.

[0070] As in the Fig. 14A to 14D, lengths of intervals for buffering an input pattern group can be implemented variously, and the capacities of memories for multiple buffering can be implemented variously according to the lengths of the intervals. In addition, as described above with reference to Fig. 13, the time selection controller 142a_3' dynamically determines the lengths of the intervals as described in the Fig. 14A to 14D, taking into account the communication environment of the terminal device, the performance of the terminal device, the workload of the terminal device, etc. In this case, the capacity of the buffer memories can be implemented taking into account the maximum length of the interval (or the maximum number of input patterns of the input pattern group).

[0071] Fig. 15 is a diagram illustrating a detailed operating method of a cell searcher (e.g., cell searcher 142) according to an exemplary embodiment of the inventive concept. Fig. 15, it is assumed that the valid cell search operation is performed based on a triple buffer operation using first to third memories MEM1 to MEM3.

[0072] Referring to Fig. 15, the cell searcher may generate the first PSS group detection result PSS_R1 by performing the first PSS group detection operation first PSS_D from the first input pattern group first ISG while buffering the first input pattern group first ISG in a first memory MEM1 in the first interval first ITV corresponding to a time between a time “t1b” and a time “t2b”.

[0073] The cell searcher buffers the second input pattern group second ISG in the second memory MEM2 in the second interval second ITV, which corresponds to the time "t2b" time to a time "t3b". The second PSS group detection result PSS_R2 can be generated from the input pattern group second ISG by performing a second PSS group detection operation second PSS_D. The cell searcher can generate the third PSS group detection result PSS_R3 from the third input pattern group third ISG by performing the third PSS group detection operation third PSS_D while buffering the third input pattern group third ISG in the third memory MEM3 in the third interval third ITV, which corresponds to a time between the time "t3b" and a time "t5b".

[0074] The cell searcher may set the SSS configuration to perform the first SSS group detection operation (first SSS_D) based on the first PSS group detection result (PSS_R1) at a specific interval F1 from a time point identical or similar to time point "t2b." The cell searcher may perform the first SSS group detection operation (first SSS_D) within the second interval (second ITV) and the third interval (third ITV) based on the set SSS configuration and generate the first SSS group detection result (SSS_R1) until time point "t4b." Thereafter, the cell searcher may determine a valid cell by using at least one of the first PSS group detection result (PSS_R1) and the first SSS group detection result (SSR_R1) during a time interval between time point "t4b" and time point "t5b."

[0075] Thereafter, when a fourth input pattern group is buffered in the first memory MEM1 in a fourth interval, the first input pattern group first ISG can be deleted from the first memory MEM1. In this way, the cell searcher can save the time for storing the first input pattern group first ISG in the first memory MEM1 by triple buffering instead of double buffering, and consequently, a first search interval VCD_ITV' in which the first valid cell search operation (i.e., the first PSS group detection operation first PSS_D and the first SSS group detection operation first SSS_D) is performed can be extended. The result of this can be applied to search intervals for other valid cell search operations, and thus the cell searcher can stably perform the valid cell search operation in extended search intervals. However, it must be understood that Fig. 15 illustrates an exemplary embodiment and multiple buffering for the input patterns may be performed by using multiple memories according to exemplary embodiments.

[0076] Fig. 16 is a flowchart illustrating a method for searching for a cell of a terminal according to an exemplary embodiment of the inventive concept.

[0077] Referring to Fig. 16, the terminal device may receive a plurality of synchronization signals (SS) from cells (S400). The terminal device may generate input patterns by performing a sampling operation on the received plurality of SSs based on a specific sampling frequency (S410). The terminal device may perform a multi-buffer operation on the input patterns by using the plurality of memories (S420). For example, the plurality of memories may alternately perform the buffer operation on each of assigned input pattern groups. The terminal device may perform the valid cell search operation for each input pattern group (S430). The terminal device may determine the valid cell as a result of performing the valid cell search operation at least once and may decode the physical transmission channel PBCH received from the determined valid cell (S440).The terminal device may determine whether the decoding of the physical transmission channel PBCH was successful (S450). If a result of operation S450 is "YES," the terminal device may report the cell search result to the valid cell (S460). If the result of operation S450 is "NO," the terminal device may receive a new SS (S470). The terminal device may re-perform the cell search including the valid cell search operation for each input pattern group based on multi-buffering (S480).

[0078] Fig. 17 is a block diagram of an electronic device 1000 according to an exemplary embodiment of the inventive concept.

[0079] Referring to Fig.17, the electronic device 1000 may include a memory 1010, a processor unit 1020, an input / output controller 1040, a display unit 1050, an input device 1060, and a communication processing unit 1090. Here, a plurality of memories 1010 may exist.

[0080] The memory 1010 may include a program storage unit 1011 for storing programs for controlling operation of the electronic device 1000 and a data storage unit 1012 for storing data generated during program execution. The data storage unit 1012 may store data used for operations of an application program 1013 and a multi-buffering-based cell search program 1014, respectively. The program storage unit 1011 may include an application program 1013 and a multi-buffering-based cell search program 1014. Here, programs contained in the program storage unit 1011 may be sets of instructions and may be expressed as instruction sets.

[0081] The application program 1013 may include application programs operable in the electronic device 1000. For example, the application program 1013 may include application instructions executed by a processor 1022. The multi-buffering-based cell search program 1014 may divide input patterns into input pattern groups, alternately buffer the plurality of memories, and perform the valid cell search operation per input pattern group according to example embodiments of the inventive concept.

[0082] A peripheral device interface 1023 may control a connection of an input / output peripheral device of a base station to the processor 1022 and a memory interface 1021. The processor 1022 may control the base station to provide an applicable service by using at least one software program. At this time, the processor 1022 may execute at least one program stored in the memory 1010 to provide a service corresponding to an applicable program.

[0083] Input / output controller 1040 may provide an interface between an input / output device such as display unit 1050 and input device 1060 and peripheral device interface 1023. For example, display unit 1050 may display status information, input characters, moving images, still images, etc. For example, display unit 1050 may display information about an application program being executed by processor 1022.

[0084] The input device 1060 may provide input data generated by a selection of the electronic device 1000 to the processor unit 1020 via the input / output controller 1040. In this case, the input device 1060 may include a keypad having at least one hardware button and a touchpad for sensing touch information. For example, the input device 1060 may provide the touch information, such as a touch, a touch gesture, and a touch release, sensed by the touchpad to the processor 1022 via the input / output controller 1040. The electronic device 1000 may include the communication processing unit 1090, which performs communication functions for voice communication and data communication.

[0085] As is traditional in the art of the present inventive concept, exemplary embodiments are described and illustrated in the drawings in units of functional blocks, units, and / or modules. Those skilled in the art will appreciate that these blocks, units, and / or modules are physically implemented by electronic (or optical) circuits such as logic circuits, discrete components, microprocessors, hardwired circuits, memory elements, wiring interconnects, etc., which may be formed using semiconductor-based manufacturing techniques or other manufacturing technologies.In the case of blocks, units, and / or modules implemented by microprocessors or the like, they may be programmed using software (e.g., microcode) to perform various functions discussed herein and may optionally be operated by firmware and / or software. Alternatively, each block, unit, and / or module may be implemented by dedicated hardware or as a combination of dedicated hardware to perform some functions and a processor (e.g., one or more programmed microprocessors and associated circuitry) to perform other functions.

[0086] While the inventive concept has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood that various changes in form and detail may be made therein without departing from the spirit and scope of the inventive concept as defined by the following claims.

Claims

[1] An operating method of a terminal (100) configured to perform a cell search by using a first memory (MEM1) and a second memory (MEM2) for buffering input patterns, the method comprising: detecting a first primary synchronization signal (PSS) group from a first input pattern group (first ISG) while buffering the first input pattern group (first ISG) in the first memory (MEM1) in a first interval (first ITV); while buffering a second input pattern group (second ISG) in the second memory (MEM2) in a second interval (second ITV) following the first interval (first ITV), detecting a second PSS group from the second input pattern group (second ISG) and a first secondary synchronization signal (SSS) group, corresponding to the first PSS group, from the first input pattern group (first ISG); and while buffering a third input pattern group (third ISG) in the first memory (MEM1) in a third interval (third ITV) following the second interval (second ITV), detecting a third PSS group from the third input pattern group (third ISG) and a second SSS group, corresponding to the second PSS group, from the second input pattern group (second ISG). [2] The method according to claim 1, wherein a number of input patterns of the first PSS group is set in advance to complete detection of the first SSS group in the second interval (second ITV), or a number of input patterns of the first PSS group used to detect the first SSS group is limited. [3] The method of claim 1, further comprising: deleting the first input pattern group (first ISG) stored in the first memory (MEM1) in the third interval (third ITV). [4] The method of claim 1, wherein detecting the first PSS group further comprises: calculating a degree of correlation between input patterns of the first input pattern group (first ISG) and PSS-based sequences; and determining the first PSS group from the first input pattern group (first ISG) based on the degree of correlation. [5] The method of claim 1, wherein detecting the first SSS group further comprises: selecting any one of input patterns included in the first PSS group; setting an SSS configuration based on information obtained from the selected input pattern; and detecting an SSS corresponding to the selected input pattern based on the set SSS configuration. [6] The method of claim 5, wherein detecting the SSS further comprises: generating an SSS-based sequence based on the set SSS configuration; calculating a degree of correlation between the SSS-based sequence and input patterns of the first input pattern group (first ISG); and a detection of the SSS based on the degree of correlation. [7] The method of claim 5, wherein the information obtained from the selected input pattern comprises: a primary identification (PID) of a cell which has transmitted the selected input pattern to the terminal (100), and time selection information of the cell corresponding to the selected input pattern. [8] The method according to claim 1, wherein the first SSS group is detected from the first input pattern group (first ISG) stored in the first memory (MEM1). [9] The method of claim 1, wherein lengths of the first interval (first ITV) to the third interval (third ITV) vary according to at least one of a communication environment of the terminal (100), a performance of the terminal (100), and a workload of the terminal (100). [10] The method of claim 1, further comprising: determining a valid cell from among a plurality of cells corresponding to the first PSS group and the first SSS group in a buffer interval (BF_ITV) of the terminal (100) comprising the first interval (first ITV) to the third interval (third ITV). [11] The method of claim 10, wherein determining the valid cell comprises: generating a comparison value from at least one of a first degree of correlation between X input patterns contained in the first PSS group and a corresponding PSS-based sequence, and a second degree of correlation between Y input patterns contained in the first SSS group and corresponding to the X input patterns and corresponding SSS-based sequences, where 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 with a reference value; and determining whether a cell corresponding to the X input patterns and the Y input patterns is the valid cell based on the comparison result. [12] The method of claim 11, 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. [13] The method of claim 10, further comprising: if at least one of the plurality of cells is determined to be the valid cell, terminating a buffer operation for the input patterns; and performing a decoding operation for a physical broadcast channel (PBCH) received from the valid cell. [14] The method of claim 13, further comprising: if the decoding operation for the PBCH is successful, reporting a cell search result to the valid cell and terminating the cell search. [15] Operating method of a terminal (100) equipped with a plurality of memories (MEM, MEM1, MEM2, MEM3) for alternately buffering input patterns generated for a cell search operation in a specific buffer interval (BF_ITV), the method comprising: buffering a first input pattern group (first ISG) used for a first valid cell search operation in a first interval (first ITV) in the first memory (MEM1); and buffering a second input pattern group (second ISG) used for a second valid cell search operation in a second interval (second ITV) following the first interval (first ITV) in a second memory (MEM2), wherein the first valid cell search operation is performed by using the first input pattern group (first ISG) in a first search interval (VCD_ITV) comprising the first interval (first ITV) and the second interval (second ITV). [16] The method of claim 15, wherein the first valid cell search operation comprises: detecting a first primary synchronization signal (PSS) group from the first input pattern group (first ISG); detecting a first secondary synchronization signal (SSS) group corresponding to the first PSS group from the first input pattern group (first ISG); and determining a valid cell by using the first PSS group and the first SSS group. [17] The method of claim 16, wherein determining the valid cell further comprises: determining whether a cell corresponding to X input patterns and Y input patterns is a valid cell based on a first degree of correlation between the X input patterns included in the first PSS group and a corresponding PSS-based sequence, and a second degree of correlation between Y input patterns included in the SSS group and corresponding to the X input patterns and a corresponding SSS-based sequence, where X is an integer equal to or greater than 1, and Y is an integer equal to or greater than 1. [18] The method of claim 16, further comprising: when the valid cell is determined in the first valid cell search operation, terminating a buffer operation for the plurality of memories (MEM, MEM1, MEM2, MEM3). [19] The method of claim 18, wherein the first valid cell search operation further comprises: performing a decoding operation for a physical transmission channel (PBCH) received from the determined valid cell; and performing or terminating the first valid cell search operation based on a decoding result for the PBCH. [20] The method of claim 15, further comprising: buffering a third input pattern group (third ISG) used for a third valid cell search operation in a third interval (third ITV) following the second interval (second ITV) in the first memory (MEM1), wherein the first input pattern group (first ISG) is deleted in the third interval (third ITV). [21] The method of claim 15, further comprising: buffering a third input pattern group (third ISG), which is used for a third valid cell search operation, in a third interval (third ITV), following the second interval (second ITV), in a third memory (MEM3), wherein the first search interval (VCD_ITV) further comprises the third interval (third ITV). [22] The method of claim 21, further comprising: buffering a fourth input pattern group (fourth ISG) used for a fourth valid cell search operation in a fourth interval (fourth ITV) following the third interval (third ITV) in the first memory (MEM1), where the first input pattern group (first ISG) is deleted in the fourth interval (fourth ITV). [23] The method of claim 15, wherein lengths of the first interval (first ITV) and the second interval (second ITV) vary according to at least one of a communication environment of the terminal (100), a performance of the terminal (100), and a workload of the terminal (100). [24] Terminal (100) comprising: a buffer (142b) divided into a first memory (MEM1) and a second memory (MEM2) for alternately buffering input patterns generated for a cell search operation in a specific buffer interval (BF_ITV); and a baseband processor configured to control a first valid cell search operation from a first input pattern group (first ISG) to be buffered in the first memory (MEM1) in a first interval during a first search interval (VCD_ITV) comprising the first interval (first ITV) and a second interval (second ITV) following the first interval (first ITV), wherein a second input pattern group (second ISG) used for a second valid cell search operation is buffered in the second interval (second ITV) in the second memory (MEM2). [25] Terminal (100) according to claim 24, wherein the baseband processor is configured to determine a cell corresponding to a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) as a valid cell, and to stop buffering for the buffer (142b) when the PSS matching a specific reference and the corresponding SSS from the first input pattern group (first ISG) are determined by the first valid cell search operation.

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