KR100881421B1 - Method for transmitting signal, method for manufacuring downlink frame and method for receiving signal - Google Patents

Abstract

A signal transmission method according to the present invention comprises the steps of applying a plurality of precoding vectors to each of a plurality of synchronization channel symbols; Applying the same precoding vector as the sync channel symbol adjacent to a broadcast channel symbol temporally adjacent to the sync channel symbol; And transmitting the sync channel symbol and the broadcast channel symbol. Accordingly, since the BCH channel is located adjacent to the SCH channel in time, transmission detection is performed by applying the same precoding vector to both channels, thereby eliminating the need for blind detection of the number of transmission antennas.

OFDM, SCH, BCH, precoding vector, sector

Description

Signal transmission method, downlink frame generation method and signal reception method {METHOD FOR TRANSMITTING SIGNAL, METHOD FOR MANUFACURING DOWNLINK FRAME 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 transmit diversity method for effective demodulation of BCH information. Another object of the present invention is to provide a signal transmission method and a signal reception method for enhancing BCH information reception quality of a mobile station at a sector boundary of a cell.

A signal transmission method according to the present invention comprises the steps of applying a plurality of precoding vectors to each of a plurality of synchronization channel symbols; Applying the same precoding vector as the sync channel symbol adjacent to a broadcast channel symbol temporally adjacent to the sync channel symbol; And transmitting the sync channel symbol and the broadcast channel symbol.

One frame includes a plurality of subframes, and the precoding vector may have a different value for each subframe.

The precoding vectors may have different values according to sectors.

The precoding vector group includes the plurality of precoding vectors, and the precoding vectors for the sectors may be applied to the subframes in different orders.

The precoding vectors may be applied in different orders depending on the cells.

Assigning a plurality of antennas to the plurality of sync channel symbols; And allocating an antenna allocated to each of the plurality of synchronization channel symbols to the broadcasting channel symbol adjacent in time to the plurality of synchronization channel symbols.

Allocating a plurality of communication resources to a plurality of the broadcast channel symbols, respectively; And dividing the plurality of communication resources into a plurality of resource groups, and assigning different phase rotation values to each of the resource groups.

The communication resource may be time and / or frequency.

In addition, the method for generating a downlink frame according to the present invention includes applying a plurality of precoding vectors to a plurality of synchronization channel symbol intervals, respectively; Applying each of the plurality of precoding vectors to a plurality of broadcast channel symbol intervals; And arranging the plurality of synchronization channel symbol sections to which the same precoding vector is applied and the plurality of broadcasting channel symbol sections in a downlink frame to be adjacent to each other in time.

The plurality of precoding vectors may be determined by subframe numbers.

The plurality of precoding vectors may additionally be determined by sector number.

The plurality of precoding vectors may additionally be determined by cell number.

The method may further include applying a plurality of phases determined by the subframe number to the plurality of synchronization channel symbol sections and the plurality of broadcast channel symbol sections so that a plurality of adjacent symbol sections may be applied with the same phase. have.

The method may further include applying a phase different from a phase applied to an adjacent sector to each of the plurality of resource intervals occupied by the plurality of broadcast channel symbol intervals.

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 using channel conditions and precoding vectors for the one or more sectors.

Demodulating the broadcast channel signal may further use a code value for the one or more sectors and a scrambling code for the one or more sectors.

Demodulating the broadcast channel signal may further use a phase rotation value according to a communication resource.

According to the present invention, it is not necessary to perform blind detection of the BCH channel bandwidth by making the BCH channel bandwidth the same as the SCH channel bandwidth. In addition, since the BCH channel is positioned adjacent to the SCH channel in time, transmission diversity is applied by applying the same precoding vector to both channels, thereby eliminating the need for blind detection of the number of transmission antennas.

In addition, when demodulating the BCH received signals from sectors in the same cell, the demodulation performance can be improved by estimating the channel using the SCH channel and coherently demodulating the BCH.

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) is a terminal, a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a user equipment (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 mobile terminal, a subscriber station, a portable subscriber station, a user device, 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 embodiment of the present invention will be described with reference to FIGS. 3 and 4.

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

Referring to FIG. 3, a sector transmitter 300 according to an embodiment of the present invention transmits a signal to an s-th sector, and includes a BCH symbol generator 410, a SCH symbol generator 420, and other channel symbol generators. 430, a first transmitter 440a, a second transmitter 440b, a sector-by-sector phase rotation / code table 450, a precoding vector switch 460, and a sector-specific precoding vector table 461. do. 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.

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

First, the BCH symbol generator 410 generates and outputs a plurality of BCH symbols.

In detail, the channel encoder 411 performs channel coding such as turbo coding or convolutional coding on the BCH data to generate and output channel encoded BCH data (S201).

The interleaver 412 generates and outputs interleaved BCH data by changing the order of channel encoded BCH data output by the channel encoder 411.

The digital modulator 413 performs digital modulation such as binary phase shift key (BPSK) and quadrature amplitude modulation (QAM) on the interleaved BCH data output from the interleaver 412. A plurality of BCH symbols are generated and output (S201).

On the other hand, the SCH symbol generator 420 generates and outputs a plurality of SCH symbols (S203).

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

The precoding vector switch 460 is a BCH symbol and a SCH symbol such 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 according to the sector-by-sector precoding vector table 461. The precoding vector is weighted to output the result (S207).

When the number of SCH symbols included in the Θ subframe in which the SCH symbol exists is N, the SCH symbol vector output from the precoding vector switch 460 satisfies Equation 1.

An SCH scrambling code such as Equation 2 is used to generate an SCH symbol vector such as Equation 1.

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 vector output from the SCH symbol generator 420 is a scrambled SCH symbol u _s using an SCH scrambling code as shown in Equation 2, and the value of the SCH symbol u _s is changed according to a standard. Can be 1 or

And so on.

The precoding vector switch 460 generates the SCH symbol vector of Equation 1 by calculating the output of the SCH symbol generator 420 as shown in Equation 3 below.

Is the frequency domain signal component of the SCH channel symbol in the θ subframe transmitted on the i th subcarrier of the nth antenna among the N subcarriers used by the SCH channel symbol assigned to the s th sector. Ψ _{Θ, s} is a code for giving a different phase difference for each subframe, and is defined as 1 when not used. Also, W _{Θ, s, ρ} are elements of the precoding vector weighted to the antenna ρ of the subframe Θ of sector s.

If the number of transmit antennas is n _t , the precoding vector of one sector for one subframe is expressed by Equation 4.

In addition, the precoding vector switch 460 obtains a transmission diversity gain by weighting Ψ _{Θ, s} and W _{Θ, s , which} are the same as the SCH symbol adjacent to the BCH symbol, to the BCH symbol of the BCH symbol generator 420.

Hereinafter, a transmission diversity scheme using precoding vector switching will be described with reference to FIGS. 5 and 6.

The precoding vector switch 460 is a subframe in which SCH and BCH symbols are arranged to obtain precoding vector switching diversity, for example, the first, sixth, eleventh, and sixteenth, as shown in FIGS. 5 and 6. Different precoding vectors W _{Θ, s} , for example, one of the first to fourth precoding vectors W 1 to W 4 may be applied to the subframe.

As illustrated in FIG. 5, the precoding vectors W _{Θ, s} for the first to third sectors of one cell 10 may be identical to each other. On the other hand, if the precoding vector (W _{Θ, s)} in a different order and a different cell, the precoding vector (W _{Θ, s)} for which is included in the first to the cells 10 one with respect to the three sectors 20 Can be applied. That is, the first to fourth precoding vectors W1 to W4 are sequentially applied to one cell 10 according to the order of subframes, and the first to fourth precoding vectors (1) are applied to other neighboring cells 20. W1-W4) may be shifted and applied.

However, as shown in FIG. 6, the precoding vectors W _{Θ, s} for the first to third sectors of one cell 10 may be different from each other, and the first to third subframes each include a SCH symbol and a BCH symbol. The precoding vectors W _{Θ, s} for the sectors 11, 12, 13 may be applied in different orders.

The precoding in the first to third sectors (11, 12, 13) of the adjacent another cell 20 vector (W _{Θ, s)} is the precoding vector (W _{Θ, s)} of a cell 10 and a They are applied in a different order. This precoding vector W _{Θ, s} has very good intersectoral orthogonality.

In this way, the diversity gain can be obtained by applying the precoding vector switching transmission diversity method. In addition _, interference may be reduced by applying different precoding vectors W _{Θ, s} between adjacent sectors or adjacent cells.

The above is an example of a precoding vector switching transmission diversity method, and the present invention is not limited thereto. On the other hand, if the suhyo of the precoding vector (W _{Θ, s)} is smaller than the sector suhyo it can be used to repeat the same precoding vector (W _{Θ, s),} this time not to each other between the sectors using the same vector interference Far enough not to.

As such, the sector transmitter 400 applies precoding vector switching to the SCH and the BCH to lower the block error rate of the SCH information and the BCH information to improve reception quality.

Meanwhile, the precoding vector switch 460 performs time-switch transmit while switching 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. diversity, TSTD) or frequency-switch transmit diversity (FSTD) may be applied to the SCH and the BCH. For example, the precoding vector switch 460 transfers the SCH symbol and the BCH symbol for some subcarriers to the first transmitter 440a, and the SCH symbol and the BCH symbol for other subcarriers, and the second transmitter 440b. ) Can be delivered.

The precoding vector switch 460 may apply the TSTD and the FSTD to the SCH and the BCH simultaneously while performing switching 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. have.

On the other hand, unlike the embodiment of the present invention, if SCH information and BCH information is transmitted, since the mobile station 200 does not know the number of antennas applied to the transmission diversity of the BCH information, it is necessary to perform blind detection. That is, since the mobile station 200 must demodulate the BCH information for each of the number of antennas 1, 2, 3, 4, etc., the mobile station 200 should perform a hypothesis test to find the best reception quality. The complexity of 200 is very high. On the other hand, as in the embodiment of the present invention, if SCH information and BCH information adjacent to each other in time are transmitted through the same antenna, the mobile station 200 does not need to perform blind detection on the number of transmit antennas of the sector transmitter. The complexity of the mobile station 200 can be reduced.

The first / second transmitter 440a / 440b receives the plurality of channel symbols from the precoding vector switch 460 to generate an OFDM symbol to generate the s-th sector through the first / second antenna 447a / 447b. To transmit.

In detail, the first / second OFDM symbol mapping unit 441a / 441b 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. (S211). That is, the first / second OFDM symbol mapping unit 441a / 441b 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 first and second OFDM symbol mapping units 441a and 441b will be described with reference to FIGS. 7 to 15.

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

As shown in FIG. 7, 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. 7, the first and second OFDM symbol mapping units 441a and 441b allocate a plurality of BCH symbols and a plurality of SCH symbols to middle bandwidths, which are common bandwidths of various system bandwidths. In addition, the first / second OFDM symbol mapping unit 441a / 441b 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.

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

Referring to FIG. 8, when the system bandwidth is 20 MHz, the first and second OFDM symbol mapping units 441a and 441b may allocate the center bandwidths of the left and right 10 MHz to the SCH and the BCH, and the center of the left and right 10 MHz. Bandwidth and center bandwidth of 20 MHz may be allocated to SCHs and BCHs, center bandwidth of 20 MHz may be allocated to SCHs and BCHs, and left and right 1.25 MHz bandwidths may be allocated to SCHs and BCHs in the middle of the system bandwidth. have.

9 to 12 illustrate downlink frames in which SCHs and BCHs are mapped according to various embodiments of the present disclosure.

9 to 12, 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.

9 to 12, the first and second OFDM symbol mapping units 441a and 441b multiplex 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. 9, the first and second OFDM symbol mapping units 441a and 441b map SCH symbols to the last OFDM symbol interval of each subframe at intervals of five subframes. The first / second 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. 10, the first and second OFDM symbol mapping units 441a and 441b map SCH symbols to the last OFDM symbol interval of each subframe at intervals of five subframes. The first / second 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. 11, the first and second OFDM symbol mapping units 441a and 441b map BCH symbols to the last OFDM symbol interval of each subframe at intervals of five subframes. The first / second OFDM symbol mapping unit 441a / 441b 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. 12, the first and second OFDM symbol mapping units 441a and 441b map SCH symbols to start OFDM symbol intervals of each subframe at intervals of five subframes. The first / second OFDM symbol mapping unit 441a / 441b maps the BCH symbol to the next OFDM symbol interval of the OFDM symbol interval to which the SCH symbol is mapped.

9 to 12, when the first / second OFDM symbol mapping unit 441a / 441b maps the SCH symbol and the BCH symbol to a downlink frame in a temporally adjacent manner, the SCH symbol and the BCH symbol have the same antenna. If transmitted over, the SCH symbol and the BCH symbol undergo 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.

13 to 15 illustrate a part of a downlink frame to which an SCH symbol and a BCH symbol are mapped according to various embodiments of the present disclosure.

13 shows a case where the number of SCHs is 1, and FIGS. 14 and 15 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. 13, the first / second OFDM symbol mapping unit 441a / 441b maps a plurality of SCH symbols at intervals of two subcarriers in one OFDM symbol period.

According to FIG. 14, the first / second OFDM symbol mapping unit 441a / 441b performs one OFDM symbol interval by frequency division multiplexing (FDM) of the plurality of P-SCH symbols and the plurality of S-SCH symbols. Assign to 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. 15, the first and second OFDM symbol mapping units 441a and 441b may use two OFDM adjacent to a plurality of P-SCH symbols and a plurality of S-SCH symbols by time division multiplexing (TDM). Assign to the symbol section. 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.

Referring back to FIG. 4, the first / second code appliers 442a / 442b perform mathematical operations on the mapped BCH symbols among the plurality of mapped symbols output by the first / second OFDM symbol mapper 441a / 441b. A code for obtaining diversity is applied as in Equation 5 (S213).

In Equation 5, k is an index of a subcarrier _{carrying a} BCH symbol, ρ is an index of a transmitting antenna, C _{k, Θρ, s} includes a precoding vector, and delay diversity or random diversity for BCH information. Is a code applied to obtain d, and _{k and s} denote a BCH symbol carried on a subcarrier k.

C _{k, Θρ, s} is defined as in Equation 6.

In this case, as described above, Ψ _{Θ, s} and W _{Θ, s} are added in the precoding vector switch 460 and Ф _{k, Θ, s} is added in the first / second code application unit 442a / 442b. .

Ф _{k, Θ, s} is defined as in Equation 7.

In Equation 7, N _T denotes the magnitude of the IFFT, Δ _{Θ, s} denotes a cyclic phase rotation value assigned to sector s, and [0,] (< N _T ) means a complex scrambling code having randomness or regularity.

In addition, the first and second code applying units 442a and 442b may define a phase rotation value to obtain delay diversity.

The first / second code application unit 442a / 442b divides the time and frequency in the time domain and frequency domain used by the first / second OFDM symbol mapping unit 441a / 441b into a plurality of resource groups.

For example, when one cell 10 includes three sectors 11, 12, and 13 as shown in FIG. 1, the first / second code appliers 442a / 442b may set the time and frequency to the first through the second. Split into third resource group.

The first / second code appliers 442a / 442b allocate different phase rotation values Δ _{s, t} to the first to third resource groups, and the first / second of each sector for the same resource group. The code appliers 442a / 442b assign different phase rotation values Δ _{s, t} . In this case, the phase rotation value Δ _{s, t} of each resource group may be an integer multiple of an arbitrary reference value.

For example, the phase rotation value Δ _{s, t} of the first resource group is applied to 0 and the phase rotation value Δ _{s, t} of the second resource group is applied to Δ with respect to the first sector 11. The phase rotation value Δ _{s, t} of the third resource group is applied to 2Δ.

The phase rotation value Δ _{s, t} of the first resource group is applied to Δ and the phase rotation value Δ _{s, t} of the second resource group is applied to 2Δ with respect to the second sector 12. The phase rotation value Δ _{s, t} of 3 resource groups is applied to 0.

In addition, the phase rotation value Δ _{s, t} of the first resource group is applied to 2Δ and the phase rotation value Δ _{s, t} of the second resource group is applied to 0 with respect to the third sector 13. , The phase rotation value Δ _{s, t} of the third resource group is applied to Δ.

As described above, by applying the phase rotation values Δ _{s, t} for each resource group by Δ _, the performance imbalance at the sector boundary can be solved.

In order to obtain high delay diversity gain between sectors, the phase rotation value must be adjusted accordingly.

Meanwhile, in order to obtain a random diversity gain, different values may be allocated to each adjacent subcarrier, a plurality of adjacent subcarriers may be grouped, and another value may be assigned to successive groups. The latter is assigned the same value to a group of subcarriers.

Per sector is given by the per phase phase rotation / code table 450. If this does not apply, the value is 1.

The first / second scrambler 443a / 443b may include a sector-specific scrambling code or a cell-specific symbol among a plurality of mapped symbols output from the first / second code appliers 442a / 442b except the SCH symbol. Scrambling with a scrambling code of generates and outputs a plurality of scrambled symbols (S215). Since scrambling the SCH symbol may make initial cell search difficult, the first / second scrambler 443a / 443b does not scramble the SCH symbol with a sector-specific scrambling code or a cell-specific scrambling code.

The first and second Fourier inverse transformers 444a and 444b inversely transform the plurality of scrambled symbols output by the first and second scramblers 443a and 443b to generate and output a signal in a time domain (S217). .

The first / second guard interval insertion unit 445a / 445b inserts a guard period such as a cyclic prefix (CP) into a time domain signal output by the first / second Fourier inverse transform units 444a / 444b. An insertion signal is generated and output (S219).

The first / second high frequency conversion unit 446a / 446b converts the guard period insertion signal output by the first / second guard period insertion unit 445a / 445b into a high frequency signal through an intermediate frequency signal (S221), The high frequency signal is amplified and transmitted to the mobile station 200 through the first and second antennas 447a and 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. 16 and 17.

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

Referring to FIG. 16, the signal receiving apparatus 500 according to an embodiment of the present invention includes an antenna 501, a down converter 503, an 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 a mapping table 521 between sector IDs, a sector-by-sector precoding vector table 523, and a 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 information about the SCH scrambling code, u _s , C _{k, Θρ, s} , sector or cell-specific scrambling code, and the like with the base station 100.

17 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 an 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 from the Fourier transform unit 511 is expressed by Equation (8).

In Equation 8, n _k is additive Gaussian noise, and H _{k, Θ, ρ, s} is a fading channel of a synchronization channel corresponding to sector s, subcarrier k, transmit antenna ρ and a specific subframe Θ. Ξ represents 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 reception symbol R _k of the subcarrier k output from the Fourier transform unit 511 is expressed as in Equation (9).

In Equation 9, n _k 'is additive Gaussian noise, and H _{k, Θ, ρ, s} is fading of a broadcast channel corresponding to sector s, subcarrier k, transmit antenna ρ, and subframe Θ. Indicates channel status. P _{k, s} denotes a scrambling code applied to the sector s, the subcarrier k, and the subframe Θ by the first / second scrambler 443a / 443b.

The channel estimator 513 estimates the state (H _{k, Θ, ρ, 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, Θ, ρ, 1} from the SCH received symbols 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, Θ, ρ, 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 symbol R _k of the subcarrier k output by the Fourier transform unit 511 using the synchronization channel states of u _s , Ф _{k, Θ, s} , p _{k, s} , and home sectors. The BCH symbol d _{k, 1} is estimated from Equation 11 from 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 queries the sector-by-sector precoding vector table 523 and the sector-by-sector phase rotation / code table 525 and scrambling the code values (Ф _{k, Θ, s} ) of the home sector and the target sector. Identify the code (p _{k, s} ). The BCH demodulator 515 uses a Fourier transform unit using u _s , Ф _{k, Θ, s} , p _{k, 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. 511) estimates the BCH symbols (d _k) of equation (12) from the BCH received symbols (R _k) of the sub-carrier k and outputting (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. 18.

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

Referring to FIG. 18, 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 a mapping table 621 between sectors and sector IDs, a sector-by-sector precoding vector table 623 and a sector-by-sector phase rotation / 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 the baseband signals.

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, Θ, ρ, 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. The two Fourier transform unit 611b estimates the state H _{k, Θ, ρ, s} of the synchronization channel with respect to the second antenna 601b using the SCH received symbols.

The BCH demodulator 615 queries the sector-by-sector precoding vector table 623 and the sector-by-sector phase rotation / code table 625 to code the code values (Ф _{k, Θ, s} ) of the home sector and the target sector and the scrambling code ( p _{k, s} ). In addition, the BCH demodulator 615 includes u _s , Ф _{k, Θ, s} , p _{k, s} , the synchronization channel state of the home sector in the first antenna 601a, and the target sector in the first antenna 601a. The BCH symbol d _k is estimated from the BCH received symbol R _k of the subcarrier k received through the first antenna 601a using the synchronization channel state. In addition, the BCH demodulator 615 includes u _s , Ф _{k, Θ, s} , p _{k, s} , the synchronization channel state of the home sector in the second antenna 601b, and the target sector in the second antenna 601b. The BCH symbol d _k is estimated from the BCH received symbol R _k of the subcarrier k received through the second antenna 601b using the synchronization channel state. The BCH demodulator 615 generates the combined BCH symbol by combining the BCH symbol d _k received from the first antenna 601a and the BCH symbol d _k received from the second antenna 601b. .

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 and 6 illustrate downlink frames in which SCH symbols and BCH symbols are mapped according to a delay diversity scheme.

6 shows bandwidth allocation for SCHs and BCHs according to an embodiment of the present invention.

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

8 to 12 illustrate downlink frames in which SCHs and BCHs are mapped according to various embodiments of the present disclosure.

13 to 15 illustrate a part of a downlink frame to which an SCH symbol and a BCH symbol are mapped according to various embodiments of the present disclosure.

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

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

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

Claims (17)

Applying a plurality of precoding vectors to each of the plurality of sync channel symbols; Applying a precoding vector identical to a precoding vector applied to the sync channel symbol to a broadcast channel symbol temporally adjacent to the sync channel symbol; And Transmitting the sync channel symbol and the broadcast channel symbol Signal transmission method comprising a. The method of claim 1, One frame includes a plurality of subframes, The precoding vector has a different value for each subframe. The method of claim 2, The precoding vector has a different value according to a sector. The method of claim 3, A precoding vector group includes the plurality of precoding vectors, And the precoding vector for each sector is applied to each subframe in a different order. The method of claim 4, wherein The precoding vector is applied in a different order according to the cell. The method of claim 5, Assigning a plurality of antennas to the plurality of sync channel symbols; And Allocating an antenna allocated to each of the plurality of synchronization channel symbols to the broadcast channel symbol adjacent in time to the plurality of synchronization channel symbols Containing more Signal transmission method. The method of claim 6, Allocating a plurality of communication resources to a plurality of the broadcast channel symbols, respectively; And Dividing the plurality of communication resources into a plurality of resource groups, and assigning different phase rotation values to each of the resource groups Containing more Signal transmission method. The method of claim 7, wherein And the communication resource is time or frequency. Applying a plurality of precoding vectors to a plurality of sync channel symbol intervals, respectively; Applying each of the plurality of precoding vectors to a plurality of broadcast channel symbol intervals; And Disposing the plurality of synchronization channel symbol sections and the plurality of broadcast channel symbol sections to which the same precoding vector is applied in a downlink frame so as to be adjacent to each other in time. Downlink frame generation method comprising a. The method of claim 9, And a plurality of precoding vectors are determined by a subframe number. The method of claim 10, And the plurality of precoding vectors are additionally determined by sector number. The method of claim 11, And a plurality of precoding vectors are additionally determined by a cell number. The method of claim 12, Applying a plurality of phases determined by the subframe number to the plurality of synchronization channel symbol sections and the plurality of broadcast channel symbol sections so that a plurality of adjacent symbol sections apply the same phase. Containing more Downlink frame generation method. The method of claim 13, Applying a phase different from a phase applied to an adjacent sector to each of a plurality of resource intervals occupied by the plurality of broadcast channel symbol intervals; Containing more Downlink frame generation method. A method for a mobile station to receive a signal transmitted 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 channel state and a precoding vector for the one or more sectors. Signal receiving method comprising a. The method of claim 15, Demodulating the broadcast channel signal And using a code value for the one or more sectors and a scrambling code for the one or more sectors. The method of claim 16, Demodulating the broadcast channel signal Signal receiving method using the phase rotation value according to the communication resource.

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