KR20100003771A - Apparatus and method for mapping cell id for mixed mode in a broadband communication system - Google Patents

Abstract

PURPOSE: A cell ID mapping apparatus and a method thereof for a share mode in a broadband wireless communications system for mapping the cell ID are provided to classify a time synchronization and a base station in a share mode. CONSTITUTION: A sequence generator(700) generates a preamble sequence according to cell ID. A modulator(702) modulates the preamble sequence. A subcarrier mapper(704) maps the forged preamble sequence in the subcarrier according to the segment ID. An OFDM modulator performs the OFDM modulation about the mapped signal. A transmitter transmits a message the preamble signal.

Description

Device ID mapping apparatus and method for coexistence mode in broadband wireless communication system {APPARATUS AND METHOD FOR MAPPING CELL ID FOR MIXED MODE IN A BROADBAND COMMUNICATION SYSTEM}

The present invention relates to an apparatus and method for performing a coexistence mode that simultaneously supports a legacy standard and a new standard in a broadband wireless communication system. In particular, the present invention relates to a cell ID of an existing standard and a cell ID of a new standard. An apparatus and method for mapping are provided.

Today, many wireless communication technologies have been proposed as candidates for high speed mobile communication. Among them, orthogonal frequency division multiplexing (OFDM) is recognized as the most powerful next generation wireless communication technology. The OFDM technology is expected to be used in most of the wireless communication technologies in the future, and the IEEE 802.16 series WMAN (Wireless Metropolitan Area Network) of the 3.5 generation technology is also adopted as the standard.

The OFDM scheme is a scheme for transmitting data using a multi-carrier. That is, a multi-carrier that modulates a serial sequence of symbols input in parallel and modulates each of them into a plurality of subcarriers having a mutual orthogonality, that is, a plurality of subchannels. It is a kind of modulation (MCM: Multi Carrier Modulation).

In the system using the OFDM scheme, the base station transmits a synchronization channel (SCH) to the terminal. When the sync channel (SCH) is located in front of a frame, it is also called a preamble. In the following description, the synchronization channel (SCH) and the preamble will be used as the same meaning. The terminal distinguishes a timing synchronization and a base station using the SCH. The position at which the SCH is transmitted is pre-defined between the transmitter and the receiver. Thus, the SCH operates as a kind of reference signal.

In a conventional IEEE 802.16e (Institute of Electrical and Electronics Engineers 802.16e) based system, the base station transmits the preamble to the IEEE 802.16e based terminal (hereinafter referred to as '16e terminal'), the 16e terminal using the preamble time Performs synchronization and base station classification. The IEEE 802.16m (Institute of Electrical and Electronics Engineers 802.16m) system currently being standardized is an evolution of the IEEE 802.16e based system (hereinafter referred to as '16e system').

If IEEE 802.16m is newly serviced where existing IEEE 802.11e is not serviced, IEEE 802.16m-based base station (hereinafter referred to as '16m base station') supports only IEEE 802.16m-based terminal (hereinafter referred to as '16m terminal'). Just do it. However, if IEEE 802.16m is served where IEEE 802.16e is served, the 16m base station must support not only the 16m terminal but also the existing 16e terminal. This case will be defined as a mixed mode.

As such, the communication system is evolving to change the specification and the like to service data at a higher speed than the existing system or to solve an implementation issue. In this evolution, various systems can coexist in the same region, depending on the degree of compatibility with existing systems. For example, a new system (eg, IEEE 802.16m) may be installed in an area where an IEEE 802.16e system (legacy system) is installed. In this case, the new system should be able to support both the legacy terminal and the new terminal.

In the coexistence mode, an IEEE 802.16e based preamble (hereinafter referred to as a '16e preamble') in a 16m base station to provide system synchronization acquisition or cell identifier (ID) information to both the 16e terminal and the 16m terminal. And IEEE 802.16m based SCH (hereinafter, referred to as '16m SCH') will be transmitted. However, since there is no performance improvement method for UEs to obtain the synchronization acquisition and cell ID information by effectively using the 16e preamble or the 16m SCH in the coexistence mode, a study on this is necessary.

Accordingly, an object of the present invention is to provide an apparatus and method for supporting both existing and new standards in a broadband wireless communication system.

Another object of the present invention is to provide an apparatus and method for mapping a cell identifier of an existing standard and a cell identifier of a new standard with each other in a broadband wireless communication system.

Another object of the present invention is to provide an apparatus and method for performing time synchronization and base station classification by a terminal of a new standard using a preamble of an existing standard in a broadband wireless communication system.

Another object of the present invention is to provide an apparatus and method for transmitting a preamble signal and a synchronization channel signal by a base station of a new standard using a mapping relationship between a cell identifier of an existing standard and a cell identifier of a new standard in a broadband wireless communication system. Is in.

According to an aspect of the present invention for achieving the above object, in the base station in the system operating in the coexistence mode supporting both the legacy (legacy) and the new (new) standard, the cell ID corresponding to the existing standard (IDCell_e) And a first transmitter for transmitting a preamble signal according to a segment ID (Segment_e), and a second transmitter for transmitting a synchronization channel (SCH) signal according to a cell identifier (IDCell_m) corresponding to a new standard. The information on the synchronization channel signal has a corresponding relationship as follows.

IDcell _m = N × Segment _e + IDcell _e (where N is SCH for Two sequence  Of the sets 2nd sequence  Belonging to a set sequence  Number)

According to another aspect of the present invention, in a system operating in a coexistence mode that supports both the legacy (legacy) and the new (new) standard, the terminal, the receiver for converting the received signal into baseband sample data, and the sample data Acquire a time synchronization using the preamble, and preamble receiving unit for detecting the cell ID (IDCell_e) and the segment ID (Segment_e) of the existing standard on the basis of the obtained time synchronization, the detected cell ID (IDCell_e) and segment ID (Segment_e) ) And a controller for acquiring a cell identifier (IDCell_m) of a new standard using the following correspondence.

IDcell _m = N × Segment _e + IDcell _e (where N is SCH for Two sequence  Of the sets 2nd sequence  Belonging to a set sequence  Number)

According to still another aspect of the present invention, in a method of transmitting a synchronization signal in a system operating in a coexistence mode supporting both a legacy standard and a new standard, a cell ID (IDCell_e) and a segment corresponding to the existing standard are provided. Transmitting a preamble signal according to an ID (Segment_e) and transmitting a SCH signal according to a cell identifier (IDCell_m) corresponding to a new standard, wherein the information on the preamble signal and the synchronization channel are included. The information on the signal is characterized by having the following correspondence.

IDcell _m = N × Segment _e + IDcell _e (where N is SCH for Two sequence  Of the sets 2nd sequence  Belonging to a set sequence  Number)

According to still another aspect of the present invention, in a method of receiving a synchronization signal in a system operating in a coexistence mode supporting both a legacy standard and a new standard, a process of converting a received signal into baseband sample data; Acquiring time synchronization using the sample data, detecting a cell ID (IDCell_e) and a segment ID (Segment_e) of an existing standard based on the obtained time synchronization, and detecting the detected cell ID (IDCell_e) and the segment. And having a ID (Segment_e), obtaining a cell identifier (IDCell_m) of a new standard by using the following correspondence.

IDcell _m = N × Segment _e + IDcell _e (where N is SCH for Two sequence  Of the sets 2nd sequence  Belonging to a set sequence  Number)

According to another aspect of the present invention, in the system operating in the coexistence mode supported by both the existing standard and the new standard, the information on the preamble of the existing standard and the synchronization channel information of the new standard has the following relationship,

IDcell _m = N × Segment _e + IDcell _e

Herein, the IDCell_m is a cell identifier of a new standard, and N is a number of sequences belonging to a second sequence set of two sequence sets for a synchronization channel, the Segment_e is a segment ID of an existing standard, and the IDcell_e is existing The cell ID of the standard is indicated, and the base station of the new standard transmits a preamble signal and a synchronization channel signal using the corresponding relationship.

As described above, the present invention proposes a mapping relationship in which a cell identifier of an existing standard is mapped to a cell identifier of a new standard when a broadband wireless communication system supports both an existing standard and a new standard. UE has an advantage of distinguishing a time synchronization and a base station using a preamble of an existing standard.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Hereinafter, in the present invention, when a legacy wireless communication system supports legacy standards (for example, IEEE 802.16e) and a new standard (for example, IEEE 802.16m), the terminal of the new standard may preamble the existing standard. A method for performing time synchronization and base station classification will be described with reference to FIG. To this end, a mapping relationship in which a cell identifier of an existing standard and a cell identifier of a new standard is corresponded to each other is required.

1 illustrates a system supporting a coexistence mode according to the present invention.

As shown, when supporting the coexistence mode, the base station (16m base station) of the new standard supports not only the terminal 16m of the new standard but also the terminal 16e of the existing standard. For example, the preambles are defined to distinguish 32 cell IDs and 3 segments. The 16m SCH of the new standard needs to distinguish a larger number of cell IDs than the existing IEEE 802.16e to support a small base station or a microcell or femtocell. As a result, the 16m SCH should consist of a signal different from the 16e preamble. Here, the 16m terminal proposed in the present invention may receive the 16e preamble and the 16m SCH transmitted from the 16m base station. In the coexistence mode, if the 16e preamble and the 16m SCH each indicating the same cell ID transmitted from the 16m base station are known, both signals can be received to estimate a single cell ID value, thereby improving performance. Therefore, in order for a 16m terminal to acquire time synchronization and a cell ID by using a 16e preamble transmitted by a 16m base station, a correspondence relationship for mapping a cell ID of a 16m SCH to a cell ID of a 16e preamble is required.

2 illustrates a structure of a downlink subframe in a system supporting a coexistence mode according to an embodiment of the present invention.

As shown, the downlink subframe in the coexistence mode is divided into a region 100 for a 16e terminal and an region 102 for a 16m terminal. The area 100 for the 16e terminal includes a preamble 104 for time synchronization and base station identification of the 16e terminal. In addition, the area 102 for the 16m terminal includes the SCH 106 for time synchronization and base station identification of the 16m terminal. Here, the 16m terminal may use the 16e preamble for time synchronization and base station division. In this case, the 16m terminal should know the mapping relationship between the cell identifier of the existing standard and the cell identifier of the new standard.

First, the preamble 104 of the existing standard is as follows.

The preamble 104 of the existing standard includes 16e cell ID information and 16e segment information. The 16e preamble 104 supports a total of 32 cell IDs from 0 to 31 and 3 segments from 0 to 2 in total. Therefore, a total of 96 cell IDs and segments can be distinguished from the preamble. In actual 16e, all 114 preamble sequences are defined, but the remaining 18 preamble sequences except 96 are allocated to cell IDs and segments overlapped with some of the 96 preambles. Although the present invention assumes that 16e has a total of 96 preambles, the present invention can be equally applied to 114 preambles.

Next, the SCH 106 of the new standard is as follows.

The SCH 106 of the new standard distinguishes base stations by one type of cell ID without distinguishing between cells and segments. The new standard system requires a large number of cell IDs for femtocell support, and it is assumed in the present invention that a total of 1024 cell IDs are used. In a conventional system, all 1024 preamble sequences are required to distinguish 1024 cell IDs. In general, as the number of sequences increases, the cell ID search complexity of the UE increases. Therefore, the new standard requires a method for a terminal to obtain a cell ID with low complexity.

Variables representing cell ID and segment in the existing 16e standard are IDcell and Segment, respectively, and variables representing cell ID in the new 16m standard are IDcell. In the present invention, the cell ID and segment of the existing 16e standard are referred to as IDcell_e and Segment_e, and the variable representing the cell ID in the new 16m standard is referred to as IDcell_m in order to avoid confusion between the existing standard and the new standard.

Here, referring to the SCH of the new standard according to the present invention, SCH sequences used for cell ID classification are divided into two sequence sets. The two sequence sets are defined as SCHSeqSet ₀ and SCHSeqSet ₁ , respectively. The number of sequences included in each of the two sequence sets (SCHSeqSet ₀ and SCHSeqSet ₁ ) is 32. The variable representing the sequence index of the first sequence set SCHSeqSet ₀ is IDcellSet ₀ and has an integer value of 0 ≦ IDcellSet ₀ <32. The variable representing the sequence index of the second sequence set (SCHSeqSet ₁ ) is IDcellSet ₁ and has an integer value of 0 ≦ IDcellSet ₁ <32. The variable IDcell _m that is the ID of the 16m base station is represented by the following <Equation 1>.

IDcell _m = 32 × ? IDcellSet ₀ + IDcellSet ₁

On the other hand, when the total number of subcarriers to be allocated to the sequence in the frequency domain of the SCH is 2L, the subcarriers are divided into two subcarrier sets, represented by SCHCarrierSet ₀ and SCHCarrierSet ₁ , respectively. The number of subcarriers included in the two subcarrier sets SCHCarrierSet ₀ and SCHCarrierSet ₁ is L, respectively. At this time, the lengths of the sequences included in the two sequence sets SCHSeqSet ₀ and SCHSeqSet ₁ are also L. At this time, the sequence set SCHSeqSet ₀ uses the subcarrier set SCHCarrierSet ₀ , and the sequence set SCHSeqSet ₁ uses the subcarrier set SCHCarrierSet ₁ .

Hereinafter, a method of grouping subcarriers for SCH into two subcarrier sets (SCHSeqSet ₀ and SCHSeqSet ₁ ) will be described. For example, it is assumed that the FFT size is 1024 and can be easily applied to other FFT sizes. It is also assumed that odd subcarriers are used for the SCH. In this case, a method of grouping 864 subcarriers into two sets except for a guard band among a total of 1024 subcarriers is as follows.

3 illustrates a case in which subcarriers of a first subcarrier set and subcarriers of a second subcarrier set are alternately positioned according to an embodiment of the present invention. As shown, SCHCarrierSet ₀ consists of 1, 5, 9, ..., 857, 861 subcarriers, and SCHCarrierSet ₁ consists of 3, 7, 11, ..., 859, 863 subcarriers.

4 illustrates a case in which a first subcarrier set and a second subcarrier set are configured in a block form according to an embodiment of the present invention.

As shown, the odd-numbered subcarriers for the SCH are defined as subcarriers of the first section based on the half, and the subcarriers in the rear section are defined as the second subcarrier set based on the half. That is, SCHCarrierSet ₀ consists of 1, 3, 5, ..., 429, 431th subcarriers, and SCHCarrierSet ₁ consists of 433, 435, 437, .., 861, 863th subcarriers.

In addition to the methods of FIGS. 3 and 4 described above, a method of dividing subcarriers usable by SCH into two subcarrier sets may be implemented in various forms.

Based on the above description, a method of obtaining a time synchronization and a cell ID by a terminal of a new standard using a preamble of an existing standard will be described.

In order for a terminal of a new standard to acquire a cell ID using a preamble of an existing standard, a mapping relationship for one-to-one correspondence of a cell identifier of a new standard SCH to a cell identifier of an existing standard preamble is required. The present invention proposes a method of mapping a cell ID (IDCell) of the existing standard to IDcellSet ₁ and a segment ID of the existing standard to IDcellSet ₀ .

When the variable a variable that refers to the cell ID of the existing standard that represents the segment ID of the IDcell _e, the existing standard to that Segment _e, to the cell ID (IDCell _m) of new standard which corresponds to the preamble of the existing standard <Equation 2 Is expressed as>

IDcell _m = 32 × Segment _e + IDcell _e

5 illustrates a correspondence between a cell identifier of an existing standard and a cell identifier of a new standard according to an embodiment of the present invention.

As shown, all of the cell identifiers IDcell_m of the new standard for distinguishing 1024 base stations are represented by 10 bits, and each consists of IDcellSet ₁ and IDcellSet ₀ , which are 5-bit information. IDcellSet ₁ is 5 bits of LSB (Least Significant Bit) of IDcell_m, and IDcellSet ₀ is 5 bits of MSB (Most Significant Bit) of IDcell_m. At this time, IDcell_e which is a cell ID of the existing standard preamble corresponds to IDcellSet1, and Segment_e representing a segment of the existing standard preamble corresponds to LSB 2 bits of IDcellSet ₀ .

Hereinafter, a specific operation of the present invention based on the above description will be described.

6 illustrates a synchronization signal transmission procedure of a new standard base station (16m base station) in a broadband wireless communication system supporting a coexistence mode according to an embodiment of the present invention.

Referring to FIG. 6, in step 601, the base station determines a cell ID (IDCell_e) and a segment ID (Segment_e) according to an existing standard. In step 603, the base station checks whether the existing standard preamble transmission interval is performed.

If the existing standard preamble transmission interval, the base station proceeds to step 605 to generate a preamble sequence according to the cell ID (IDCell_e), and the base station modulates the generated sequence in step 607. For example, The base station may modulate the sequence into a power boosted BPSK signal.

In step 609, the base station maps the modulated preamble sequence to a subcarrier according to the segment ID (Segment_e). In step 611, the base station modulates the subcarrier-mapped preamble sequence by orthogonal frequency division multiplexing (OFDM) to generate a preamble signal (preamble symbol). In step 613, the base station RF-processes the generated preamble signal and transmits the generated preamble signal to the terminal. The preamble signal may be transmitted in a predetermined section of the frame, and may be transmitted at regular time intervals.

On the other hand, if the existing standard preamble transmission interval in step 603, the base station proceeds to step 615 to check whether the new standard SCH transmission interval. In case of the new standard SCH transmission interval, the base station proceeds to step 617 and uses the mapping relationship as shown in Equation 2 to determine the cell ID (IDCell_e) and the segment ID (Segment_e) of the new standard cell ID (IDCell_m). Convert to

In step 619, the base station generates two sequences according to the cell ID IDCell_m of the new standard. The base station modulates the generated two sequences in step 607.

In step 609, the base station maps the modulated first sequence to subcarriers of a first subcarrier set, and maps the modulated second sequence to subcarriers of a second subcarrier set. In this case, the first sequence and the second sequence may be mapped to odd or even subcarriers for two repetition patterns in the time domain. For example, the first subcarrier set and the second subcarrier set may be configured with FIG. 3 or 4 described above.

In step 611, the base station modulates the subcarrier mapped first sequence and the second sequence by orthogonal frequency division multiplexing (OFDM) to generate a synchronization channel signal (synchronous channel symbol). In step 613, the base station performs RF processing on the generated sync channel signal and transmits the generated sync channel signal to the terminal. The sync channel signal may be transmitted in a predetermined section of a frame, and may be transmitted at regular time intervals.

7 is a block diagram of a new standard base station (16m base station) in a broadband wireless communication system supporting a coexistence mode according to an embodiment of the present invention.

As shown, the base station includes a sequence generator 700, a modulator 702, a subcarrier mapper 704, an inverse fast fourier transform (IFFT) operator 706, a cyclic prefix adder 708, a DAC ( And a digital to analog converter (710) and a radio frequency (RF) transmitter 712.

Referring to FIG. 7, first, the sequence generator 700 receives a cell ID IDCell_e and a segment ID Segment_e according to an existing standard from an upper controller (not shown). If the existing standard preamble transmission interval, the sequence generator 700 generates a preamble sequence according to the cell ID (IDCell_e). If the new standard SCH transmission interval, the sequence generator 700 is the Using the mapping relationship as shown in Equation 2, the cell ID (IDCell_e) and the segment ID (Segment_e) are converted into the cell ID (IDCell_m) of the new standard, and the sequence according to the cell ID (IDCell_m) of the new standard ( In another embodiment, the sequence generator 700 stores a preamble sequence of an existing standard and a SCH sequence of a new standard, and under the control of an upper controller, one of the two sequences is generated. In this case, information about the preamble of the existing standard (IDCell_e and Segment_e) and information about the SCH of the new standard (IDCell_m) Have a relationship such as the following expression (2).

The modulator 702 modulates and outputs a sequence (preamble sequence or SCH sequence) from the sequence generator 700 according to a predetermined modulation scheme. For example, the modulator 702 modulates the sequence into a power boosted Binary Phase Shift Keying (BPSK) signal and outputs the modulated sequence.

The subcarrier mapper 704 maps the sequence from the modulator 702 to the corresponding subcarrier set according to a predetermined rule. For example, the preamble sequence of the existing standard may be mapped to the subcarrier according to the segment ID, and the SCH sequence (the first sequence and the second sequence) of the new standard may be mapped according to FIG. 3 or 4 described above.

 The IFFT operator 706 IFFTs the subcarrier mapped signal from the subcarrier mapper 704 and outputs sample data in the time domain. The CP adder 708 generates a synchronization signal (a preamble signal or an SCH signal) by adding a guard period (eg, CP) to the sample data from the IFFT operator 706.

The DAC 710 converts the synchronization signal from the CP adder 710 into an analog signal and outputs the analog signal. The RF transmitter 712 converts the baseband analog signal from the DAC 710 into an RF signal and transmits the RF signal through the antenna.

8 is a flowchart illustrating an operation procedure of a new standard terminal (16m terminal) in a broadband wireless communication system supporting a coexistence mode according to an embodiment of the present invention.

Referring to FIG. 8, first, a terminal (16m terminal) accessing a base station converts an RF signal received from the base station into baseband sample data in step 801 and stores it. In step 803, the terminal acquires time synchronization using the sample data based on the existing standard (IEEE 802.16e), and searches for the cell ID of the existing standard based on the obtained time synchronization.

Here, although time synchronization acquisition is assumed to be performed in the time domain, the time synchronization acquisition may also be performed in the frequency domain. It is assumed that the cell ID search is performed in the frequency domain. For example, the terminal extracts subcarrier values to which a preamble sequence is mapped from a frequency domain signal after FFT operation, and searches a cell ID by correlating the extracted values with a sequence corresponding to each cell ID.

In step 805, the terminal checks the calculated correlation values and checks whether a correlation value equal to or greater than a set value exists. If a correlation value that is greater than or equal to the set value is detected, the terminal considers that a cell ID has been obtained, determines a segment ID (Segment_e) and a cell ID (IDCell_e) corresponding to the correlation value, and then proceeds to step 807. do.

On the other hand, if the correlation value that is greater than the set value does not exist, the terminal determines that the cell ID acquisition according to the existing standard has failed and proceeds to step 809. In step 809, the terminal acquires time synchronization using the stored sample data based on the new standard (IEEE 802.16m), and searches for a cell ID of the new standard based on the obtained time synchronization.

Here, although time synchronization acquisition is assumed to be performed in the time domain, the time synchronization acquisition may also be performed in the frequency domain. It is assumed that the cell ID search is performed in the frequency domain. For example, the terminal extracts first subcarrier values mapped to a first sequence of SCHs and second subcarrier values mapped to a second sequence from a frequency domain signal after FFT operation. The terminal calculates first correlation values by correlating the extracted first subcarrier values with each sequence of a pre-stored first sequence set (SCHSeqSet ₀ ), and extracts the second subcarrier values and a second stored sequence sequence. Correlate each sequence of (SCHSeqSet ₁ ) to calculate second correlation values.

In step 811, the terminal examines the first correlation values and the second correlation values and checks whether a correlation value equal to or greater than a set value exists. If a first correlation value that is greater than or equal to the set value and a second correlation value that is greater than or equal to the set value is detected, the terminal considers that a cell ID is obtained and the first sequence index corresponding to the first correlation value (IDCellSet _0). ) And a second sequence index IDCellSet ₁ corresponding to the second correlation value. The terminal acquires a cell identifier IDCell_m of a new standard by using the first sequence index and the second sequence index (see Equation 1).

In this way, the terminal having obtained the time synchronization and the cell ID decodes the data received from the base station in step 613.

On the other hand, when the segment ID (Segment_e) and the cell ID (IDCell_e) of the existing standard is obtained in step 805, the terminal uses the mapping relationship as shown in Equation 2 in step 807 (IDCell_m) ). Thereafter, the terminal proceeds to step 813 to decode the data received from the base station.

9 is a block diagram of a new standard terminal in a system supporting a coexistence mode according to an embodiment of the present invention.

As shown, the terminal includes an RF processor 900, an analog to digital converter (ADC) 902, a cyclic prefix remover 904, a time synchronization acquirer 906, and a fast fourier transform (FFT) operator ( 908, a subcarrier demapper 910, a demodulator 912, a decoder 914, an existing standard cell ID obtainer 916, a controller 918, and a new standard cell ID obtainer 919.

Referring to FIG. 9, the RF processor 900 converts a signal of an RF band received through an antenna into a baseband signal and outputs the signal. The ADC 902 converts the analog baseband signal from the RF processor 900 into digital sample data and outputs the digital sample data.

The CP remover 904 obtains OFDM symbol synchronization from the sample data from the ADC 902, and removes and outputs a guard interval (eg, Cyclic Prefix) based on the OFDM symbol synchronization. The time synchronization acquirer 906 temporarily buffers the sample data from the CP remover 904, obtains a time synchronization (or frame synchronization) from the buffered sample data, and provides the same to the upper controller. The time synchronization obtainer 906 outputs sample data in OFDM symbol units on the basis of the obtained time synchronization. Here, although it is assumed that frame synchronization (time synchronization) is obtained in the time domain, frame synchronization may also be obtained in the frequency domain.

The FFT operator 906 performs fast Fourier transform on the sample data from the time synchronization acquirer 906 to output data in the frequency domain. The subcarrier demapper 910 extracts a preamble signal mapped to a predetermined tone (three subcarrier intervals) in the case of a preamble reception interval of the existing standard and provides the cell to the existing standard cell ID obtainer 916. If the SCH reception interval of a new standard, the subcarrier demapper 910 extracts an SCH signal mapped to a predetermined tone interval (two subcarrier intervals) and provides it to a new standard cell ID obtainer 919. . If the data reception period, the subcarrier demapper 910 extracts a data packet (burst or PDU) from the data in the frequency domain and provides it to the demodulator 912.

The existing standard cell ID obtainer 916 correlates the received preamble signal from the subcarrier demapper 919 and each of prestored preamble sequences (existing standards), and correlates more than a set value among the calculated correlation values. Check if the value exists. When a correlation value greater than or equal to the set value is detected, the existing standard cell ID acquirer 916 determines the segment ID Segment_e and the cell ID IDCell_e corresponding to the detected correlation value and provides the same to the controller 918. do.

As such, when the segment ID (Segment_e) and the cell ID (IDCell_e) of the existing standard are obtained, the controller 918 uses the mapping relationship of Equation 2 to obtain the cell ID (IDCell_m) of the new standard. Acquire. The controller 918 then controls the corresponding component to decode the data received from the base station. If the acquisition of the cell identifier of the existing standard fails, the controller 918 controls the configuration unit to acquire the cell ID using the SCH of the new standard.

The new standard cell ID obtainer 919 extracts first values corresponding to a first sequence and second values corresponding to a second sequence from a received SCH signal from the subcarrier mapper 910. The new standard cell ID obtainer 919 calculates first correlation values by correlating each of the extracted first values and a pre-stored first sequence set (SCHSeqSet ₀ ), and calculates the first correlation values. The second correlation values are calculated by correlating each sequence of the previously stored second sequence set (SCHSeqSet ₁ ), and then, the new standard cell ID obtainer 919 calculates the second correlation values. If the first correlation value that is greater than or equal to the set value and the second correlation value that is greater than or equal to the set value is detected, the new standard cell ID obtainer 919 detects the detection. Determine a first sequence index IDCellSet ₀ corresponding to the first correlation value and a second sequence index IDCellSet ₁ corresponding to the detected second correlation value, and determine the first sequence index and the second sequence. Index of new standard cell ID (IDCe) ll_m) (see Equation 1).

Thereafter, the terminal decodes the data received from the base station. The demodulator 912 demodulates and outputs a received packet from the subcarrier demapper 910. The decoder 914 decodes the demodulated data from the demodulator 912 to restore the information data.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

1 is a diagram illustrating a system supporting a coexistence mode according to the present invention.

2 is a diagram illustrating a structure of a downlink subframe in a system supporting a coexistence mode according to an embodiment of the present invention.

3 is a diagram illustrating a case in which subcarriers of a first subcarrier set and subcarriers of a second subcarrier set are alternately positioned according to an embodiment of the present invention.

4 is a diagram illustrating a case in which a first subcarrier set and a second subcarrier set are configured in a block form according to an embodiment of the present invention.

5 is a diagram illustrating a correspondence relationship between a cell ID of an existing standard and a cell ID of a new standard according to an embodiment of the present invention.

6 is a diagram illustrating a synchronization signal transmission procedure of a new standard base station (16m base station) in a broadband wireless communication system supporting a coexistence mode according to an embodiment of the present invention.

7 is a block diagram of a new standard base station (16m base station) in a broadband wireless communication system supporting a coexistence mode according to an embodiment of the present invention.

8 is a diagram illustrating an operation procedure of a new standard terminal in a broadband wireless communication system supporting a coexistence mode according to an embodiment of the present invention.

9 is a block diagram of a new standard terminal in a system supporting a coexistence mode according to an embodiment of the present invention;

Claims (22)

In a base station in a system operating in a coexistence mode that supports both legacy and new standards, A first transmitter for transmitting a preamble signal according to a cell ID (IDCell_e) and a segment ID (Segment_e) corresponding to an existing standard; A second transmitter for transmitting a synchronization channel (SCH) signal according to a cell identifier (IDCell_m) corresponding to the new standard, The base station, characterized in that the information on the preamble signal and the information on the synchronization channel signal has a corresponding relationship as follows. = N × _m IDcell Segment _e + IDcell _e (where, N represents the number of sequences belonging to the second sequence set of the two sequences set for SCH) The method of claim 1, The IDCell_m includes a total of 10 bits, the lowest 5 bits correspond to the cell ID IDCell_e, the lower 2 bits of the highest 5 bits correspond to the segment ID (Segment_e), and the upper 3 bits of the highest 5 bits And a base station set to '0'. The method of claim 1, wherein the second transmitting unit, The base station, characterized in that for converting the cell ID (IDCell_e) and segment ID (Segment_e) to a cell identifier (IDCell_m) of a new standard according to the corresponding relationship. The method of claim 1, wherein the first transmitter, A sequence generator for generating a preamble sequence according to the cell ID (IDCell_e); A modulator for modulating the preamble sequence from the sequence generator; A subcarrier mapper for mapping a modulated preamble sequence from the modulator to a subcarrier according to the segment ID; An OFDM modulator that OFDM modulates a subcarrier mapped signal from the subcarrier mapper and generates a preamble signal; And a transmitter for RF-processing and transmitting the preamble signal from the OFDM modulator. The method of claim 1, wherein the second transmitting unit,  A sequence generator for generating a first sequence and a second sequence according to the cell identifier IDCell_m; A modulator for modulating the first sequence and the second sequence from the sequence generator; A subcarrier mapper that maps the first sequence from the modulator to subcarriers of a first subcarrier set, and maps the second sequence to subcarriers of a second subcarrier set, the first subcarrier set and the second subcarrier set; The configured subcarriers have two subcarrier spacings, An OFDM modulator for OFDM modulating a subcarrier mapped signal from the subcarrier mapper to generate a synchronization channel symbol; And a transmitter for transmitting a radio frequency (RF) process of the sync channel symbol from the OFDM modulator. In the terminal in the system operating in the coexistence mode supporting both the legacy (legacy) and the new (new) standard, A receiver for converting the received signal into baseband sample data; A preamble receiving unit for acquiring time synchronization using the sample data and detecting a cell ID (IDCell_e) and a segment ID (Segment_e) of an existing standard based on the obtained time synchronization; And a controller having the detected cell ID (IDCell_e) and segment ID (Segment_e), and obtaining a cell identifier (IDCell_m) of a new standard using a next correspondence. IDcell _m = N × ? Segment _e + IDcell _e, where N is two for SCH sequence Of the sets Number of sequences in the second set of sequences ) The method of claim 6, The cell identifier (IDCell_m) of the new standard consists of a total of 10 bits, the lowest 5 ratios correspond to the cell ID (IDCell_e), the lower 2 bits of the most significant 5 bits correspond to the segment ID (Segment_e), and the highest The upper 3 bits of the 5 bits is characterized in that the terminal is set to '0'. The method of claim 6, And a synchronization channel receiver for receiving a synchronization channel signal according to the new standard. The method of claim 8, wherein the synchronization channel receiver, A time synchronization obtainer for acquiring time synchronization using the sample data from the receiver; An FFT operator for generating data in a frequency domain by performing FFT operation on sample data input based on the time synchronization reference; A subcarrier demapping unit for extracting a first SCH sequence and a second SCH sequence from data of a frequency domain from the FFT operator; Compute first correlation values by correlating the extracted first SCH sequence with each sequence of a prestored first sequence set, and correlating each sequence of the extracted second SCH sequence with a prestored second sequence set to generate a second correlation value. When the first correlation value and the second correlation value that are greater than or equal to a predetermined value are detected and the correlation values are calculated, the first sequence index IDCellSet ₀ corresponding to the detected first correlation value and the second correlation value correspond to the second correlation value. And a cell identifier (IDCell_m) of a new standard is obtained using a second sequence index (IDCellSet ₁ ). The method of claim 9, The cell identifier (IDCell_m) of the new standard is characterized in that obtained by the following equation. IDcell_m = N ₁ × IDcellSet ₀ + IDcellSet ₁ (where N ₁ represents the number of sequences in the second sequence set). In a method of transmitting a synchronization signal in a system operating in a coexistence mode that supports both legacy and new standards, Transmitting a preamble signal according to a cell ID (IDCell_e) and a segment ID (Segment_e) corresponding to an existing standard; Transmitting a synchronization channel (SCH) signal according to a cell identifier (IDCell_m) corresponding to the new standard, And the information on the preamble signal and the information on the synchronization channel signal have a corresponding relationship as follows. IDcell _m = N × ? Segment _e + IDcell _e, where N is two for SCH sequence Of the sets Number of sequences in the second set of sequences ) The method of claim 11, The IDCell_m consists of 10 bits in total, the lowest 5 bits correspond to the cell ID (IDCell_e), the lower 2 bits among the most significant 5 bits correspond to the segment ID (Segment_e), and the upper 3 bits among the most significant 5 bits. Is set to '0'. The method of claim 11, And converting the cell ID (IDCell_e) and the segment ID (Segment_e) into a cell identifier (IDCell_m) of a new standard according to the correspondence relationship. The method of claim 11, wherein the preamble signal transmission process comprises: Generating a preamble sequence according to the cell ID (IDCell_e); Modulating the generated preamble sequence; Mapping the modulated preamble sequence to a subcarrier according to the segment ID; Generating a preamble signal by OFDM modulating the subcarrier mapped signal; And RF-processing the OFDM modulated signal and transmitting the RF signal. The method of claim 11, wherein the synchronization channel signal transmission process,  Generating a first sequence and a second sequence according to the cell identifier IDCell_m; Modulating the generated first and second sequences; Mapping the modulated first sequence to subcarriers of a first subcarrier set, mapping the modulated second sequence to subcarriers of a second subcarrier set, and configured to the first subcarrier set and the second subcarrier set Subcarriers have two subcarrier spacings, Generating a sync channel symbol by OFDM modulating the subcarrier mapped signal; And transmitting the OFDM modulated signal by RF (Radio Frequency) processing. In a method of receiving a synchronization signal in a system operating in a coexistence mode that supports both legacy and new standards, Converting the received signal into baseband sample data; Acquiring time synchronization using the sample data and detecting a cell ID (IDCell_e) and a segment ID (Segment_e) of an existing standard based on the obtained time synchronization; And having a detected cell ID (IDCell_e) and a segment ID (Segment_e), obtaining a cell identifier (IDCell_m) of a new standard by using a next correspondence relationship. IDcell _m = N × Segment _e + IDcell _e (where N is SCH for Two sequence  Of the sets 2nd sequence  Belonging to a set sequence  Number) The method of claim 16, The cell identifier (IDCell_m) of the new standard consists of a total of 10 bits, the lowest 5 ratios correspond to the cell ID (IDCell_e), the lower 2 bits of the most significant 5 bits correspond to the segment ID (Segment_e), and the highest The upper 3 bits of 5 bits are set to '0'. The method of claim 16, Receiving a synchronization channel signal according to the new standard. 19. The method of claim 18, wherein the synchronization channel reception process is performed. Acquiring time synchronization using the sample data; Generating data in the frequency domain by performing FFT operation on the sample data based on the time synchronization; Extracting a first SCH sequence and a second SCH sequence from the data of the frequency domain; Compute first correlation values by correlating the extracted first SCH sequence with each sequence of a prestored first sequence set, and correlating each sequence of the extracted second SCH sequence with a prestored second sequence set to generate a second correlation value. Calculating correlation values, When a first correlation value and a second correlation value that are equal to or greater than a set value are detected, a first sequence index IDCellSet ₀ corresponding to the detected first correlation value and a second sequence index IDCellSet corresponding to the second correlation value. ₁ ) using the step of obtaining a cell identifier (IDCell_m) of a new standard. The method of claim 19, The cell identifier (IDCell_m) of the new standard is obtained by the following equation. IDcell_m = N ₁ × IDcellSet ₀ + IDcellSet ₁ (where N ₁ represents the number of sequences in the second sequence set). In a system operating in coexistence mode supported by both old and new standards, The information on the preamble of the existing standard and the synchronization channel information of the new standard have the following correspondence. IDcell _m = N × Segment _e + IDcell _e Herein, the IDCell_m is a cell identifier of a new standard, and N is a number of sequences belonging to a second sequence set of two sequence sets for a synchronization channel, the Segment_e is a segment ID of an existing standard, and the IDcell_e is existing Represents the cell ID of the standard, The base station of the new standard transmits a preamble signal and a synchronization channel signal using the correspondence relationship. The method of claim 21, The cell identifier (IDCell_m) of the new standard consists of a total of 10 bits, the lowest 5 ratios correspond to the cell ID (IDCell_e), the lower 2 bits of the most significant 5 bits correspond to the segment ID (Segment_e), and the highest The upper 3 bits of 5 bits are set to '0'.

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