KR100903868B1 - Method for transmitting signal and method for receiving signal - Google Patents

Abstract

According to an aspect of the present invention, there is provided a signal transmission method comprising: allocating a plurality of communication resources to a plurality of broadcast channel symbols; Dividing the plurality of communication resources into a plurality of resource groups; Assigning a plurality of different phase rotation values to each of the plurality of resource groups; And transmitting the broadcast channel symbol. Accordingly, when demodulating broadcast channel information coming from sectors of the same cell using an intersector delay diversity technique, a per-sector phase rotation value may be assigned to solve a performance imbalance occurring at a sector boundary.

SCH, BCH, Sector, TSTD, Phase Rotation Value

Description

Signal transmission method and signal reception method {METHOD FOR TRANSMITTING SIGNAL AND METHOD FOR RECEIVING SIGNAL}

The present invention relates to a method of transmitting a signal and a method of receiving a signal.

The mobile station must efficiently receive BCH information in the initial access phase while supporting OFDM based system bandwidth from 1.25 MHz to 20 MHz. And the mobile station should be able to receive the BCH information with a reception quality of more than the reference value.

However, in order to improve the reception quality of the BCH information, the complexity of the mobile station occurs.

An object of the present invention is to provide a signal transmission method and a signal reception method for improving BCH information reception quality of a mobile station at a sector boundary of a cell.

According to an aspect of the present invention, there is provided a signal transmission method comprising: allocating a plurality of communication resources to a plurality of broadcast channel symbols; Dividing the plurality of communication resources into a plurality of resource groups; Assigning a plurality of different phase rotation values to each of the plurality of resource groups; And transmitting the broadcast channel symbol.

The step of assigning the plurality of phase rotation values may assign a phase rotation value different from the phase rotation value allocated by the adjacent sector to each of the plurality of resource groups.

The group of the plurality of phase rotation values and the group of the plurality of phase rotation values allocated by the adjacent sectors may be the same.

The allocating to the plurality of resource groups may divide the plurality of communication resources according to time and / or frequency.

The number of resource groups may be equal to the number of sectors.

The method may further include mapping a plurality of sync channel symbols and the plurality of broadcast channel symbols to a downlink frame in a temporally adjacent manner.

The mapping to the downlink frame may include allocating a first bandwidth to the plurality of sync channel symbols; And allocating the first bandwidth to the plurality of broadcast channel symbols.

In addition, the signal transmission method according to the present invention comprises the steps of: allocating a plurality of communication resources divided into a plurality of resource groups to a plurality of broadcast channel symbols, respectively; Assigning a plurality of different phase rotation values to each of the plurality of resource groups; And transmitting the broadcast channel symbol.

Allocating the plurality of phase rotation values comprises assigning each of the plurality of resource groups a phase rotation value different from a phase rotation value allocated by a neighboring sector for each of the plurality of resource groups; The group of the plurality of phase rotation values and the group of the plurality of phase rotation values allocated by the neighboring sectors may be the same.

A method of receiving a signal from a base station that manages a plurality of sectors, the method comprising: receiving a downlink signal; Extracting a synchronization channel signal and a broadcast channel signal from the downlink signal; Identifying one or more sectors affecting the mobile station from the plurality of sectors from the sync channel signal; Estimating a channel state for the one or more sectors from the sync channel signal; And demodulating the broadcast channel signal by using a plurality of phase rotation values corresponding to a plurality of resource groups occupied by the broadcast channel signal and channel states for the one or more sectors.

The demodulating the broadcast channel signal may further demodulate the broadcast channel signal using a code value for the one or more sectors and a scrambling code for the one or more sectors.

According to the present invention, when demodulating broadcast channel information coming from sectors of the same cell using an intersector delay diversity technique, a per-sector phase rotation value may be allocated to solve a performance imbalance occurring at a sector boundary.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. have.

In this specification, a mobile station (MS) includes a terminal, a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), and a user equipment. It may also refer to a user equipment (UE), an access terminal (AT), and the like, and may include all or some functions of a terminal, a mobile terminal, a subscriber station, a portable subscriber station, a user device, an access terminal, and the like.

In the present specification, a base station (BS) is an access point (AP), a radio access station (Radio Access Station, RAS), a Node B (Node B), a base transceiver station (Base Transceiver Station, BTS), MMR ( Mobile Multihop Relay) -BS and the like, and may include all or part of functions such as an access point, a radio access station, a Node B, a base transceiver station, and an MMR-BS.

Hereinafter, a communication system according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

1 is a diagram illustrating a communication system according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating a base station according to an embodiment of the present invention.

Referring to FIG. 1, the communication system includes a base station 100 and a mobile station 200. Referring to FIG. 2, the base station 100 includes a first sector transmitter 110, a second sector transmitter 120, and The third sector transmitter 130 is included.

Base station 100 manages cell 10. The cell 10 is composed of a first sector 11, a second sector 12, and a third sector 13. In the embodiment of the present invention, the cell 10 is described as being composed of three sectors. Alternatively, the cell 10 may be composed of two or four sectors. Base station 100 communicates with mobile station 200 within cell 10.

The first sector transmitter 110, the second sector transmitter 120, and the third sector transmitter 130 manage the first sector 11, the second sector 12, and the third sector 13, respectively. . That is, the first sector transmitter 110 communicates with the mobile station in the first sector 11, the second sector transmitter 120 communicates with the mobile station in the second sector 12, and the third sector transmitter 130 Communicate with the mobile station in the third sector 13.

The first sector transmitter 110, the second sector transmitter 120, and the third sector transmitter 130 each have a synchronization channel (eg, a first sector 11, a second sector 12, and a third sector 13). Synchronization channel (SCH) information and broadcast channel (BCH) information are transmitted. SCH information varies from sector to sector, and BCH information is common to all sectors. That is, SCH information is distinguished according to sectors, and BCH information is distinguished according to cells. The BCH information is transmitted on a predefined independent physical channel known to all mobile stations 200. The first sector transmitter 110, the second sector transmitter 120, and the third sector transmitter 130 are synchronized so that the mobile station 200 can demodulate the BCH information through soft-combining.

In an embodiment of the present invention, a sector to which the mobile station 200 belongs to among the plurality of sectors constituting the cell 10 is called a home sector, and the received power of a threshold value or more adjacent to the mobile station among the sectors excluding the home sector. A sector for transmitting a signal is called a target sector.

Hereinafter, a sector transmitter according to an exemplary embodiment of the present invention will be described with reference to FIGS. 3 to 5.

3 is a block diagram illustrating a sector transmitter according to an embodiment of the present invention.

Referring to FIG. 3, the sector transmitter 300 according to an embodiment of the present invention transmits a signal to the s-th sector, and includes a BCH symbol generator 310, an SCH symbol generator 320, and other channel symbol generators. 330, and a transmitter 340. The BCH symbol generator 310 includes a channel encoder 311, an interleaver 312, and a digital modulator 313. The transmitter 340 includes an OFDM symbol mapping unit 341, a code application unit 342, a scrambler 343, a Fourier inverse transform unit 344, a guard interval insertion unit 345, a high frequency converter 346, and an antenna ( 347, and a sector-specific code table 348.

4 is a flowchart illustrating a sector transmission method according to an embodiment of the present invention.

First, the BCH symbol generator 310 generates and outputs a plurality of BCH symbols.

In detail, the channel encoder 311 performs channel coding such as turbo coding or convolutional coding on the BCH data to generate and output channel encoded BCH data (S101).

The interleaver 312 changes the order of the channel encoded BCH data output by the channel encoder 311 to generate and output interleaved BCH data (S103).

The digital modulator 313 performs digital modulation such as binary phase shift key (BPSK), quadrature amplitude modulation (QAM), etc. on the interleaved BCH data output from the interleaver 312 ( In step S105, a plurality of BCH symbols are generated and output (S107).

Meanwhile, the SCH symbol generator 320 generates and outputs a plurality of SCH symbols. When the number of SCH symbols included in the subframe in which the SCH is present is N, the SCH symbol generator 320 generates and outputs an SCH symbol vector as shown in Equation 1 for the sector s.

The SCH symbol generation unit 320 uses an SCH scrambling code as shown in Equation 2 to generate an SCH symbol vector as shown in Equation 1 below.

The SCH scrambling code for one subframe in one frame may be different from or the same as the SCH scrambling code for another subframe.

등이 될 수 있다.The SCH symbol generator 320 scrambles the SCH symbol u _s using the SCH scrambling code shown in Equation 2 to generate the SCH symbol vector shown in Equation 1. In this case, the elements A _{i, s} of the SCH symbol vector may be obtained by Equation 3 below. The value of the SCH symbol u _s may be changed according to the specification, and 1 or

And so on.

The other channel symbol generator 330 generates SCH symbols shown in Equations 1, 2, and 3, and also generates and outputs a plurality of other channel symbols (S109).

The transmitter 340 may include a plurality of BCH symbols output by the BCH symbol generator 310, a plurality of SCH symbols output by the SCH symbol generator 320, and a plurality of others output by the channel symbol generator 330. An OFDM symbol is generated with the channel symbol and transmitted to the s th sector through the antenna 347.

In detail, the OFDM symbol mapping unit 341 outputs a plurality of mapped symbols by mapping a plurality of BCH symbols, a plurality of SCH symbols, and a plurality of other channel symbols to a time domain and a frequency domain (S111). That is, the OFDM symbol mapping unit 341 performs time division multiplexing and frequency division multiplexing on a plurality of BCH symbols, a plurality of SCH symbols, and a plurality of other channel symbols.

Hereinafter, a mapping method of the OFDM symbol mapping unit 341 will be described with reference to FIGS. 5 to 13.

5 shows bandwidth allocation for SCH and BCH according to one embodiment of the present invention.

As shown in FIG. 5, the sector transmitter 300 may use various bandwidths such as 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz as the system bandwidth.

Referring to FIG. 5, the OFDM symbol mapping unit 341 allocates a plurality of BCH symbols and a plurality of SCH symbols to a middle bandwidth, which is a common bandwidth of various system bandwidths. In addition, the OFDM symbol mapping unit 341 allocates a bandwidth equal to the bandwidth allocated to the plurality of SCH symbols to the plurality of BCH symbols. Thus, the mobile station 200 does not need to perform blind detection on the BCH bandwidth in order to demodulate the BCH symbol.

6 shows bandwidth allocation for SCH and BCH according to another embodiment of the present invention.

Referring to FIG. 6, when the system bandwidth is 20 MHz, the OFDM symbol mapping unit 341 may allocate the center bandwidth of the left and right 10 MHz to the SCH and the BCH, the center bandwidth of the left and right 10 MHz, and the center bandwidth of the 20 MHz. May be allocated to the SCH and the BCH, the middle bandwidth of 20 MHz may be allocated to the SCH and the BCH, and the left and right bandwidths of 1.25 MHz may be allocated to the SCH and the BCH in the center of the system bandwidth.

7 to 10 illustrate downlink frames in which SCHs and BCHs are mapped according to various embodiments of the present disclosure.

7 to 10, a downlink frame according to an embodiment of the present invention is composed of 20 subframes. SCH and BCH are mapped to 1.25 MHz in the center of the system bandwidth.

According to the embodiment of FIGS. 7 to 10, the OFDM symbol mapping unit 341 multiplexes BCH information into four subframes during one downlink frame period. The BCH information is transmitted to the mobile station 200 in the form of a packet. One BCH information packet may be multiplexed in one frame and transmitted every 10 msec, and may be multiplexed in two or more frames and 20 msec, 30 msec, or 40 msec. May be sent.

An embodiment of the present invention may use a multiplexing method for transmitting BCH information through a unicast channel, or a multiplexing method for transmitting a BCH information through a multicast channel, a multimedia broadcast and multicast service (MBMS) channel, and the like. Can also be used.

According to FIG. 7, the OFDM symbol mapping unit 341 maps SCH symbols to the last OFDM symbol interval of each subframe at intervals of five subframes. The OFDM symbol mapping unit 341 maps the BCH symbol to the next OFDM symbol interval of the OFDM symbol interval to which the SCH symbol is mapped.

According to FIG. 8, the OFDM symbol mapping unit 341 maps SCH symbols to the last OFDM symbol interval of each subframe at intervals of five subframes. The OFDM symbol mapping unit 341 maps the BCH symbol to previous OFDM symbol intervals of the OFDM symbol interval to which the SCH symbol is mapped.

According to FIG. 9, the OFDM symbol mapping unit 341 maps BCH symbols to the last OFDM symbol interval of each subframe at intervals of five subframes. The OFDM symbol mapping unit 341 maps the SCH symbol to the next OFDM symbol interval of the OFDM symbol interval to which the SCH symbol is mapped.

According to FIG. 10, the OFDM symbol mapping unit 341 maps SCH symbols in the start OFDM symbol period of each subframe at intervals of five subframes. The OFDM symbol mapping unit 341 maps the BCH symbol to the next OFDM symbol interval of the OFDM symbol interval to which the SCH symbol is mapped.

As shown in FIGS. 7 to 10, when the OFDM symbol mapping unit 341 maps the SCH symbol and the BCH symbol to the downlink frame adjacent in time, if the SCH symbol and the BCH symbol are transmitted through the same antenna, the SCH symbol and the BCH symbol are transmitted. The symbol undergoes the same channel fading. Accordingly, the mobile station 200 may coherently demodulate the BCH information using the estimated information of the SCH. On the other hand, the performance of channel estimation using a pilot channel in which reference signals are arranged at intervals of six subcarriers is better than that of channel estimation using SCH, in which synchronization symbols are arranged at intervals of one or two subcarriers. Can not do it.

11 to 13 illustrate a portion of a downlink frame to which an SCH symbol and a BCH symbol are mapped according to various embodiments of the present disclosure.

11 shows a case where the number of SCHs is 1, and FIGS. 12 and 13 show a case where the number of SCHs is two. When the number of SCHs is two, one is called a primary synchronous channel (P-SCH) and the other is called a secondary chronization channel (S-SCH).

According to FIG. 11, the OFDM symbol mapping unit 341 maps a plurality of SCH symbols at intervals of two subcarriers in one OFDM symbol period.

According to FIG. 12, the OFDM symbol mapping unit 341 allocates a plurality of P-SCH symbols and a plurality of S-SCH symbols to one OFDM symbol interval by frequency division multiplexing (FDM). In this case, when the sequence for the P-SCH is common to all sectors 11, 12, 13 and the base station 100, the S-SCH may be used for channel estimation. In addition, when there are three or more sequences for the P-SCH and they are allocated to sectors, if different sequences are allocated between adjacent sectors, the P-SCH can also be used for BCH channel estimation like the S-SCH. .

According to FIG. 13, the OFDM symbol mapping unit 341 allocates a plurality of P-SCH symbols and a plurality of S-SCH symbols to two adjacent OFDM symbol intervals by time division multiplexing (TDM). In this case, the S-SCH may be used for channel estimation. Also as mentioned above, the P-SCH can also be used for channel estimation. If the S-SCH occupies an odd or even subcarrier, the mobile station 200 can estimate the channel on this odd or even subcarrier. If the S-SCH occupies all subcarriers, the mobile station 200 can estimate the channel on all these subcarriers.

The OFDM symbol mapping unit 341 may use a multiplexing method for transmitting BCH information through a unicast channel, or multiplexing through a multicast channel, a multimedia broadcast and multicast service (MBMS) channel, and the like. You can also use the method.

The code applying unit 342 applies a code for obtaining diversity to the mapped BCH symbol among the plurality of mapped symbols output from the OFDM symbol mapping unit 341 as shown in Equation 4 (S113).

In this case, k is an index of a subcarrier carrying a BCH symbol, a is an index of a transmission antenna, u _s is a value according to Equation 3, and p _{k, t, s} means a sector-specific scrambling code. C _{k, t, a, s} is a code applied to obtain delay diversity or random diversity for BCH information, and d _{k, t} means a BCH symbol carried on subcarrier k.

In the Multiple Input Multiple Output (MIMO) mode, C _{k, t, a, s} may be defined as in Equation 5 to obtain delay diversity.

In this case, N _T denotes the size of the IFFT, and Δ _{s, t} denotes a cyclic phase rotation value assigned to the sector s.

Hereinafter, referring to FIG. 14, a phase rotation value setting method for solving an imbalance between sectors will be described.

14 illustrates a method of setting a phase rotation value according to an embodiment of the present invention.

Referring to FIG. 14, the code applier 342 divides a resource for BCH symbol transmission into a plurality of resource groups 351, 352, and 353. In this case, the code applying unit 342 may divide resources for BCH symbol transmission according to time, may divide according to frequency, or may divide according to time and frequency. The number of resource groups 351, 352, and 353 may be equal to the number of sectors forming one cell, or may be larger than the number of sectors.

For example, when one cell 10 includes three sectors 11, 12, and 13, as shown in FIG. 1, the code applier 342 allocates resources for transmitting BCH symbols to first to third resource groups. Divide into (351, 352, 353).

The code applier 342 allocates different phase rotation values Δ _{s, t} to the first to third resource groups 351, 352, and 353.

In this case, the code applying unit 342 of the first to third sectors 11, 12, and 13 with respect to any of the resource groups 351, 352, and 353 of the first to third resource groups 351, 352, and 353. ) Assigns different phase rotation values Δs _{, t} . In this case, the phase rotation value Δ _{s, t of} each resource group 351, 352, and 353 may be an integer multiple of an arbitrary reference value, and the phase rotation value Δ _s for each of the sectors 11, 12, and 13. _{, t} ) may be set by extracting one phase rotation value Δ _{s, t} from the same group of phase rotation values.

For example, the phase rotation value of the first resource group 351 with respect to the first sector (11) (△ _{s, t)} is set to 0, the phase rotation value of the second resource groups (352) (△ _{s, t} ) is set to Δ, and the phase rotation value Δ _{s, t} of the third resource group 353 is 2Δ. Is set to.

A second sector phase rotation value of the first resource group 351 with respect to _{(12) (△ s, t} ) is set to △, the phase rotation value of the second resource groups _{(352) (△ s, t} ) is 2 Δ, and the phase rotation value Δ _{s, t} of the third resource group 353 is set to zero.

In addition, the third sector phase rotation value of the first resource group 351 with respect to (13) (△ _{s, t)} is 2, is set to △, the second resource group 352, the phase rotation value (△ _{s, t} of ) Is set to 0, and the phase rotation value Δs _{, t} of the third resource group 353 is set to Δ.

As such, the phase rotation values Δ _{s, t} for each resource group 351, 352, 353 are Δ By shifting by setting, the performance imbalance at the sector boundary can be solved.

At this time, in order to obtain a high delay diversity gain between sectors, the phase rotation value DELTA _{s, t} must be appropriately adjusted.

In addition, C _{k , t, a, s} may be defined as in Equation 6 to obtain a random diversity gain.

는 랜덤 변수를 의미한다.In Equation 6,

Denotes a random variable.

Meanwhile, the code applier 342 may apply a complex random code having a size of 1 to each other according to sectors to the mapped BCH symbols for random diversity. The code application unit 342 may apply the code sequence such that the code sequence allocated to one subcarrier is different from the code sequence allocated to an adjacent subcarrier. In addition, the code applying unit 342 may apply a code sequence such that a code sequence allocated to one subcarrier group and a code sequence allocated to an adjacent subcarrier group are different while applying the same code sequence to a plurality of subcarriers in the subcarrier group. . The code application unit 342 applies a sector-specific code to the BCH symbols mapped according to the sector-specific code table 348.

Referring back to FIG. 4, the scrambler 343 scrambles a plurality of symbols except for the SCH symbol among the plurality of mapped symbols output by the code application unit 342 by using a sector-specific scrambling code or a cell-specific scrambling code. A scrambled symbol is generated and output (S115). Scrambling the SCH symbol can make initial cell search difficult, so the scrambler 343 does not scramble the SCH symbol with a sector-specific scrambling code or a cell-specific scrambling code.

The Fourier inverse transform unit 344 generates and outputs a signal in a time domain by performing fast Fourier inverse transform on the plurality of scrambled symbols output from the scrambler 343 (S117).

The guard interval inserting unit 345 inserts a guard interval such as a cyclic prefix (CP) into a time domain signal output from the Fourier inverse transformer 344 to generate and output a guard interval insertion signal (S119).

The high frequency conversion unit 346 converts the guard period insertion signal output by the guard period insertion unit 345 into a high frequency signal through an intermediate frequency signal (S121), amplifies the high frequency signal, and amplifies the radio frequency signal through the antenna 347. To be sent).

15 is a block diagram illustrating a sector transmitter according to another embodiment of the present invention.

Referring to FIG. 15, a sector transmitter 400 using a time-switched transmit diversity (TSTD) and two transmit antennas includes a BCH symbol generator 410, a SCH symbol generator 420, and the like. The channel symbol generator 430, the first transmitter 440a, the second transmitter 440b, the sector-specific code table 450, and the switch 460 are included. The BCH symbol generator 410 includes a channel encoder 411, an interleaver 412, and a digital modulator 413.

The first transmitter 440a includes a first OFDM symbol mapping unit 441a, a first code applying unit 442a, a first scrambler 443a, a first IFFT 444a, and a first guard interval insertion unit 445a. The first high frequency converter 446a and the first antenna 447a are included.

The second transmitter 440b includes a second OFDM symbol mapping unit 441b, a second code applying unit 442b, a second scrambler 443b, a second IFFT 444b, and a second guard interval insertion unit 445b. , A second high frequency conversion unit 446b and a second antenna 447b.

16 is a flowchart illustrating a sector transmission method using TSTD according to another embodiment of the present invention.

While describing FIG. 16, the description overlapped by FIG. 4 may be omitted.

First, the BCH symbol generator 410 generates a plurality of BCH symbols and outputs them to the switch 460 (S201).

The SCH symbol generator 420 generates a plurality of SCH symbols and outputs the plurality of SCH symbols to the switch 460 (S203).

The other channel symbol generator 430 generates and outputs a plurality of other channel symbols (S205).

The switch 460 switches so that a plurality of BCH symbols and SCH symbols adjacent in time to the plurality of BCH symbols can be transmitted through the same antenna (S207).

The first OFDM symbol mapping unit 441a and the second OFDM symbol mapping unit 441b map the received plurality of BCH symbols, the plurality of SCH symbols, and the plurality of other channel symbols to the time domain and the frequency domain, respectively, to map the plurality of mappings. Each symbol is output (S211).

The first code applier 442a and the second code applier 442b may be configured to map BCHs among a plurality of mapped symbols output by the first OFDM symbol mapper 441a and the second OFDM symbol mapper 441b, respectively. Codes for obtaining diversity are applied to the symbols as shown in Equations 4 and 5, respectively (S213). In this case, the code for obtaining the delay diversity has different phase rotation values DELTA _{s, t} for each of the sectors 11, 12, and 13 with respect to the same resource groups 351, 352, and 353 as shown in FIG.

The first scrambler 443a and the second scrambler 443b may sector the plurality of symbols except for the SCH symbol among the plurality of mapped symbols output by the first code applying unit 442a and the second code applying unit 442b, respectively. By scrambling with a unique scrambling code or a cell-specific scrambling code, a plurality of scrambled symbols are generated and output (S215).

The first Fourier inverse transform unit 444a and the second Fourier inverse transform unit 444b respectively perform fast Fourier inverse transforms on a plurality of scrambled symbols output by the first scrambler 443a and the second scrambler 443b, respectively, to obtain a signal in a time domain. Generate and output each (S217).

The first guard interval inserting portion 445a and the second guard interval inserting portion 445b are cyclic prefixes of the time domain signals output from the first Fourier inverse transformer 444a and the second Fourier inverse transformer 444b, respectively. The guard interval insertion signals are respectively inserted into the guard interval insertion signal (S219) and output.

The first high frequency conversion unit 446a and the second high frequency conversion unit 446b respectively convert the guard period insertion signals output by the guard period insertion unit 445 into the high frequency signals through the intermediate frequency signal (S221). The signal is amplified and transmitted to the mobile station 200 through the first antenna 447a and the second antenna 447b.

Hereinafter, a signal receiving apparatus of a mobile station according to an embodiment of the present invention will be described with reference to FIGS. 17 and 18.

17 is a block diagram of a signal receiving apparatus according to an embodiment of the present invention.

Referring to FIG. 17, the signal receiving apparatus 500 according to an embodiment of the present invention includes an antenna 501, a down converter 503, a SCH BCH band filter 505, and a cell search unit 507. , Guard interval remover 509, Fourier transform 511, channel estimator 513, BCH demodulator 515, BCH decoder 517, other channel demodulator 519 for demodulating other channels, base station ID And sector mapping table 521, sector code table 523 defined in Equations 5 and 6, and sector-by-sector phase rotation / scrambling code table 525.

The mapping table 521 between the base station ID and the sector ID is a table in which the relationship between the base station and the sector ID assigned to the base station is defined. In the mapping table 521 between the base station ID and the sector ID, the sector ID assigned to the base station is displayed, and if the base station uses only one sector, the remaining sector ID is not used.

The mobile station 200 shares with the base station 100 information about the SCH scrambling code, u _s , C _{k, t, a, s} , a sector- or cell-specific scrambling code, and the like.

18 is a flowchart illustrating a signal reception method according to an embodiment of the present invention.

First, the down converter 503 converts a downlink signal received through the antenna 501 into a baseband signal and outputs it (S301).

The SCH BCH band filter 505 filters the SCH band signal and the BCH band signal from the baseband signal output by the down converter 503 (S303).

The cell search unit 507 identifies the home sector and one or more target sectors through the SCH band signal output from the SCH BCH band filter 505 (S305). To this end, the cell search unit 507 obtains symbol synchronization, frequency synchronization, and frame synchronization through initial cell search, and estimates a sector identifier (ID). The cell search unit 507 considers the sector having the largest estimated correlation value as the home sector while estimating the sector ID, and identifies one or more candidate sectors having the estimated correlation value equal to or greater than a predetermined threshold. The cell search unit 507 refers to the mapping table 521 between the base station ID and the sector ID, and considers a sector of the base station to which the mobile station 200 belongs as a target sector among one or more candidate sectors.

The guard interval removing unit 509 removes a guard interval such as CP from the signal of the SCH band and the signal of the BCH band (S307).

The Fourier transform unit 511 performs fast Fourier transform on the signal of the SCH band and the signal of the BCH band from which the guard interval is removed, and generates and outputs a plurality of SCH received symbols and a plurality of BCH received symbols carried on a plurality of subcarriers ( S309).

The SCH reception symbol flowing into the specific reception antenna of the subcarrier k output by the Fourier transform unit 511 is expressed by Equation (7).

In Equation 7, n _{k, t} is additive Gaussian noise, and H _{k, t, a, s} is the sync channel corresponding to sector s, subcarrier k, transmit antenna a, and specific subframe t. Fading channel condition, ξ representing the number of sectors affecting the mobile station 200. For example, when ξ = 2, sector s (= 1) is the home sector and sector s (= 2) is the target sector.

The BCH received symbols R _{k and t} of the subcarrier k output from the Fourier transform unit 511 are expressed as shown in Equation (8).

In Equation 8, n _{k, t} 'is additive Gaussian noise, and H' _{k, t, a, s} are broadcasts corresponding to sector s, subcarrier k, transmit antenna a, and subframe t. Indicates the fading channel state of the channel. P _{k, t, s} denotes a scrambling code applied to the sector s, the subcarrier k, and the subframe t by the scramblers 343, 443a, and 443b.

The channel estimator 513 estimates the state H _{k, t, a, s} of the synchronization channel between the home sector and the target sector using the SCH received symbols output from the Fourier transform unit 511. First, the channel estimator 513 determines whether there is a target sector found from the cell searcher 507 (S311).

If the cell search unit 507 fails to obtain the target sector ID, the cell search unit 507 estimates the channel state H _{k, t, a, 1} from the SCH received symbol of the home sector (S313).

In detail, the channel estimator 513 conjugates the conjugate conjugate of the SCH scrambling code to the SCH received symbol output by the Fourier transform unit 511 to obtain the synchronization channel state H _{k, t, a, 1} of the home sector. Multiply by Eq.

)을 구한다. The channel estimator 513 performs frequency domain filtering, such as Hamming filtering, for Equation 10, and generates a time domain signal by performing fast Fourier inverse transform. The channel estimator 513 performs gating to leave only a specific time domain and zero the rest to reduce the interference signal component and noise component of the generated time domain signal. The channel estimator 513 performs fast Fourier transform on the gated signal and performs frequency domain inverse filtering to estimate an estimated value of the sync channel state H _{k , 1} of the home sector.

)

The BCH demodulator 515 receives the BCH received symbols of the subcarrier k output from the Fourier transform unit 511 using the synchronization channel states of u _s , C _{k, t, a, s} , p _{k, t, s} , and home sector. The BCH symbol d _{k , t} is estimated from (R _{k, t} ) (S315).

On the other hand, when the cell search unit 507 obtains the target sector ID, the channel estimator 513 estimates the synchronization channel state of the home sector from the SCH received symbols of the home sector (S313), and then calculates the target sector ID from the SCH received symbols of the target sector. The synchronization channel state is estimated (S317).

The BCH demodulator 515 estimates the BCH symbol by performing coherent soft-combining demodulation as shown in Equation (11). That is, the BCH demodulator 515 inquires the sector-specific code table 523 and the sector-by-sector phase rotation / scrambling code table 525 to search the code values C _{k, t, a, s of} the home sector and the target sector. Determine the scrambling code (p _{k, t, s} ). The BCH demodulator 515 uses u _s , C _{k, t, a, s} , p _{k, t, s} , the fading channel state of the sync channel of the home sector and the fading channel state of the sync channel of the target sector. The BCH symbol d _{k, t} is estimated from the BCH received symbols R _{k, t} of the subcarrier k output by the Fourier transform unit 511 (S319).

The BCH decoder 517 decodes a plurality of BCH symbols output from the BCH demodulator 515 such as Viterbi decoding to generate BCH information (S321).

Hereinafter, a signal receiving apparatus of a mobile station 200 according to another embodiment of the present invention will be described with reference to FIG. 19.

19 is a block diagram of a signal receiving apparatus according to another embodiment of the present invention.

Referring to FIG. 19, the signal receiving apparatus 600 according to another embodiment of the present invention may include a first antenna 601a, a second antenna 601b, a first down converter 603a, and a second down converter 603b. The first SCH BCH band filter 605a, the second SCH BCH band filter 605b, the cell search unit 607, the first guard interval remover 609a, the second guard interval remover 609b, and the first Fourier transformer 611a, second Fourier transformer 611b, channel estimator 613, BCH demodulator 615, BCH decoder 617, other channel demodulator 619 for demodulating other channels, base station ID And sector-specific code table 623 and sector-by-sector phase rotation / scrambling code table 625.

The first down converter 603a and the second down converter 603b convert the downlink signals received through the first antenna 601a and the second antenna 601b into baseband signals and output them.

The first SCH BCH band filter 605a and the second SCH BCH band filter 605b are used to convert the SCH band signal and the BCH band from the baseband signals output by the first down converter 603a and the second down converter 603b. Filter each signal and output it.

The cell search unit 507 identifies the home sector and one or more target sectors through signals of the SCH band output by the first SCH BCH band filter 605a and the second SCH BCH band filter 605b.

The first guard period remover 609a and the second guard period remover 609b may include a signal of the SCH band and the BCH band output by the first SCH BCH band filter 605a and the second SCH BCH band filter 605b. Remove guard intervals such as CP from the signal, respectively.

The first Fourier transform unit 611a and the second Fourier transform unit 611b may include signals of the SCH band from which the guard intervals output by the first guard interval remover 609a and the second guard interval remover 609b are removed. Fast Fourier transforms a signal in a BCH band to generate and output a plurality of SCH received symbols and a plurality of BCH received symbols carried on a plurality of subcarriers. The SCH received symbol of the subcarrier k may be represented by Equation 7, and the BCH received symbol of the subcarrier k may be represented by Equation 8.

The channel estimator 613 estimates the state (H _{k, t, a, s} ) of the synchronization channel with respect to the first antenna 601a using the SCH reception symbols output from the first Fourier transform unit 611a _, and Using the SCH reception symbols output from the two Fourier transform unit 611b, the state H _{k, t, a, s} of the synchronization channel with respect to the second antenna 601b is estimated.

The BCH demodulator 615 queries the sector-by-sector code table 623 and the sector-by-sector phase rotation / scrambling code table 625 to code the code values C _{k, t, a, s of} the home sector and the target sector and the scrambling code. Identify (p _{k, t, s} ). And, the BCH demodulator 615 is u _s , C _{k, t, a, s} , p _{k, t, s} , in the sync channel state of the home sector in the first antenna 601a, in the first antenna 601a. The BCH symbol d _{k, t} is estimated from the BCH reception symbols R _{k, t} of the subcarrier k received through the first antenna 601a using the synchronization channel state of the target sector of. Further, the BCH demodulator 615 is u _s , C _{k, t, a, s} , p _{k, t, s} , and the synchronization channel state of the home sector in the second antenna 601b, in the second antenna 601b. The BCH symbol d _{k, t} is estimated from the BCH received symbols R _{k, t} of the subcarrier k received through the second antenna 601b using the synchronization channel state of the target sector of. BCH demodulation section 615, is a BCH symbol combining by combining the first antenna the BCH symbols (d _{k, t)} and the BCH symbols (d _{k, t)} received from a second antenna (601b) received from (601a) Create and print

The BCH decoder 617 generates BCH information by performing decoding such as Viterbi decoding on the plurality of combined BCH symbols output from the BCH demodulator 615.

The embodiments of the present invention described above are not implemented only through the apparatus and the method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. Implementation may be easily implemented by those skilled in the art from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a diagram illustrating a communication system according to an embodiment of the present invention.

2 is a diagram illustrating a base station according to an embodiment of the present invention.

3 is a block diagram illustrating a sector transmitter according to an embodiment of the present invention.

4 is a flowchart illustrating a sector transmission method according to an embodiment of the present invention.

5 shows bandwidth allocation for SCH and BCH according to one embodiment of the present invention.

6 shows bandwidth allocation for SCH and BCH according to another embodiment of the present invention.

7 to 10 illustrate downlink frames in which SCHs and BCHs are mapped according to various embodiments of the present disclosure.

11 to 13 illustrate a portion of a downlink frame to which an SCH symbol and a BCH symbol are mapped according to various embodiments of the present disclosure.

14 illustrates a method of setting a phase rotation value according to an embodiment of the present invention.

15 is a block diagram illustrating a sector transmitter according to another embodiment of the present invention.

16 is a flowchart illustrating a sector transmission method using TSTD according to another embodiment of the present invention.

17 is a block diagram of a signal receiving apparatus according to an embodiment of the present invention.

18 is a flowchart illustrating a signal reception method according to an embodiment of the present invention.

19 is a block diagram of a signal receiving apparatus according to another embodiment of the present invention.

Claims (11)

Allocating a plurality of communication resources to a plurality of broadcast channel symbols, respectively; Dividing the plurality of communication resources into a plurality of resource groups; Assigning a plurality of different phase rotation values to each of the plurality of resource groups; And Transmitting at least one of the plurality of broadcast channel symbols Signal transmission method comprising a. The method of claim 1, Assigning the plurality of phase rotation values And a phase rotation value different from a phase rotation value allocated to a neighboring sector for each of the plurality of resource groups, to each of the plurality of resource groups. The method of claim 2, And the group of the plurality of phase rotation values and the group of the plurality of phase rotation values allocated by the neighboring sectors are the same. The method of claim 3, The dividing into the plurality of resource groups And dividing the plurality of communication resources according to time and / or frequency. The method of claim 3, And the number of resource groups is equal to the number of sectors forming one cell. The method of claim 5, Mapping a plurality of sync channel symbols and the plurality of broadcast channel symbols to a downlink frame, wherein the plurality of sync channel symbols and the plurality of broadcast channel symbols are mapped adjacent to each other on a time axis of the downlink frame. Signal transmission method further comprising. The method of claim 6, The mapping to the downlink frame Allocating a first bandwidth to the plurality of sync channel symbols; And Allocating the first bandwidth to the plurality of broadcast channel symbols Containing Signal transmission method. Allocating a plurality of communication resources divided into a plurality of resource groups to a plurality of broadcast channel symbols, respectively; Assigning a plurality of different phase rotation values to each of the plurality of resource groups; And Transmitting at least one of the plurality of broadcast channel symbols Signal transmission method comprising a. The method of claim 8, Assigning the plurality of phase rotation values Assigning each of the plurality of resource groups a phase rotation value different from a phase rotation value allocated by a neighboring sector for each of the plurality of resource groups; And the group of the plurality of phase rotation values and the group of the plurality of phase rotation values allocated by the neighboring sectors are the same. In a method for receiving a signal from a base station that manages a plurality of sectors, Receiving a downlink signal; Extracting a synchronization channel signal and a broadcast channel signal from the downlink signal; Identifying one or more sectors affecting the mobile station from the plurality of sectors from the sync channel signal; Estimating a channel state for the one or more sectors from the sync channel signal; And Demodulating the broadcast channel signal using a plurality of phase rotation values respectively corresponding to a plurality of resource groups occupied by the broadcast channel signal and channel states for the one or more sectors. Signal receiving method comprising a. The method of claim 10, Demodulating the broadcast channel signal And demodulating the broadcast channel signal further using a code value for the one or more sectors and a scrambling code for the one or more sectors.

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