WO2014098401A1 - Terminal, method whereby terminal receives information, base station, and method whereby base station transmits information - Google Patents

Abstract

The present invention relates to information transmission by a base station comprising the steps of: scrambling and performing quadrature phase-shift keying (QPSK) modulation, layer mapping, and precoding on one physical broadcast channel (PBCH) transmission bit block comprising bits the number of which corresponds to the number (M_bit) of coded bits to be transmitted in a PBCH; and, with there being at least one radio frame having the radio frame index n _f wherein n _f mod4 = 0 and four consecutive radio frames including said radio frame, mapping each bit of the precoded PBCH transmission bit block by increasing the frequency index k, OFDM symbol index, and radio frame index n _f in ascending order from subframe #0 or a predetermined slot in subframe #0 of the four radio frames, with respect to resource elements (k, l), which have not been allocated for reference signal transmission, among complex symbol blocks (y ^(P) (0),..., and y ^(P) (M _symb -1)) in respective antenna ports.

Description

A terminal, a method of receiving information of a terminal, a base station, and a method of transmitting information of a base station

The present invention relates to an apparatus and method for transmitting and receiving MIB (Master Information Block information) based on DMRS.

According to the 3GPP LTE-Advanced standardization trend, various discussions on carriers are underway, and one item is a new carrier type (NCT), hereinafter referred to as 'NCT'.

NCT is a non-primary CC among component carriers (CC) hereinafter merged through a carrier aggregation (CA) technique. The CC refers to a secondary CC that reduces overhead to increase payload size in CC, that is, a component carrier that does not include a control region. These NCTs are classified into standalone NCT (S-NCT) and non-standalone NCT (NS-NCT) types. It is divided into NCT, and control signals such as Physical Downlink Control Channel (PDCCH), Physical HARQ Indicator Channel (PHICH), Physical Control Format Indicator Channel (PCFICH), and Cell-specific Reference Signal (CRS) will not be transmitted in NCT. to be.

However, the terminal transmits a master information block (MIB), which is system information, through a PBCH (Physical Broadcast Channel) among control signals after the cell discovery process, and after the system information is received and decoded, the terminal performs a random access process You can access the cell via

However, since the CRS is not transmitted in the NCT, a problem may occur in reception and demodulation of a control channel such as a conventional PBCH based on the CRS.

In the present invention, to provide a terminal, an information receiving method of a terminal, a base station and a base station information transmission method for providing a MIB which is system information based on DMRS in NCT.

According to an embodiment of the present invention, one physical broadcast channel (PBCH) transport bit block including a number of bits corresponding to the number of encoded bits M _{bits to} be transmitted on a physical broadcast channel (PBCH) is provided. Performing scrambling on the DMA, performing quadrature phase-shift keying (QPSK) modulation, layer mapping, and precoding; and radio frame index n _f is

There is at least one radio frame that satisfies, and for four consecutive radio frames including the radio frame, a complex symbol block y ^(p) (0), ..., y ^(p) at each antenna port Frequency index k in ascending order in a specific slot of subframe 0 or subframe 0 of the 4 radio frames for (k, l) resource elements not allocated for reference signal transmission among (M _symb- 1). And mapping each bit of the precoded PBCH transmission bit block by increasing the OFDM symbol index l and increasing the index n _f of the radio frame. To provide.

According to another embodiment of the present invention, one physical broadcast channel (PBCH) transport bit block including a number of bits corresponding to the number of encoded bits (M _bits ) to be transmitted on a physical broadcast channel (Physical Broadcast CHannel, PBCH) Performs scrambling on the device, performs quadrature phase-shift keying (QPSK) modulation, layer mapping and precoding, and at least one radio frame index n _f satisfies n _f mod4 = 0. A radio frame exists, and in four consecutive radio frames, including the corresponding radio frame, of each of the complex symbol blocks y ^(p) (0), ..., y ^(p) (M _symb -1) at each antenna port. Increase the frequency index k in ascending order in the specific slot of subframe 0 or subframe 0 for (k, l) resource elements not allocated for reference signal transmission, increase the OFDM symbol index l, and Phosphorus frame 'S increases the n _f, a controller for mapping the pre-coding performed the PBCH for each bit of the transmission bit block, characterized in that it comprises; and a transmitter for transmitting a MIB (Master Information Block) via the mapping of PBCH Channel Provide a base station.

According to another embodiment of the present invention, a physical broadcast channel (PBCH) is searched based on a demodulation reference signal (DMRS) and a master information block (MIB) transmitted through the PBCH. Extracting at least one radio frame in which the radio frame index n _f satisfies n _f mod4 = 0, and includes four consecutive radio frames while including the corresponding radio frame. For a frame, (k, l) unallocated (k, l) resource elements for the reference signal transmission in the complex symbol blocks y ^(p) (0), ..., y ^(p) (M _symb -1) at each antenna port. For the PBCH by increasing the frequency index k, increasing the OFDM symbol index l, and increasing the index n _f of the radio frame in ascending order in a specific slot of subframe 0 or subframe 0 of the four radio frames for I'm It provides a method for receiving information of a terminal, characterized in that for searching each bit of the song bit block.

According to another embodiment of the present invention, a physical broadcast channel (PBCH) is searched based on a demodulation reference signal (DMRS) and a master information block (MIB) transmitted through the PBCH. And a receiving unit for extracting a); wherein the receiving unit includes at least one radio frame in which the radio frame index n _f satisfies n _f mod 4 = 0 and includes the corresponding radio frame in the PBCH search. For each consecutive radio frame, one of the complex symbol blocks y ^(p) (0), ..., y ^(p) (M _symb -1) at each antenna port is not allocated for reference signal transmission (k, l ) For the resource elements, the frequency index k is increased in ascending order in the specific slot of subframe 0 or subframe 0 of the 4 radio frames, the OFDM symbol index l is increased, and the index n _f of the radio frame is Increase To provide a terminal, it characterized in that to search for the respective bits of the PBCH transmission bit block.

According to the present invention, channel estimation performance of PBCH can be improved based on DMRS while preventing collision between PSS / SSS and demodulation reference signal (DMRS) for NCT that does not include a control region in a CA environment.

In addition, PBCH can be adaptively allocated according to various DMRS patterns to avoid collision with PSS / SSS, thereby reducing PBCH channel estimation error and effectively providing system information, thereby enabling fast and accurate cell access.

1 is a diagram illustrating a communication system to which embodiments of the present invention are applied.

2 is a diagram illustrating a PBCH transport channel processing procedure.

3 is a view for explaining an RS and PBCH allocation scheme.

4 is a diagram for explaining a cell access procedure to which the present invention is applied.

5 and 6 illustrate examples for explaining a PBCH mapping scheme according to an embodiment of the present invention.

7 is another example for explaining a PBCH mapping scheme according to an embodiment of the present invention.

8 is a diagram illustrating another example for explaining a PBCH mapping scheme according to an embodiment of the present invention.

9 and 10 illustrate another example for explaining a PBCH mapping scheme according to an embodiment of the present invention.

FIG. 11 is a diagram illustrating another example for describing a PBCH mapping scheme according to an embodiment of the present invention. FIG.

12 is a diagram for explaining a DMRS pattern according to another embodiment of the present invention.

13 and 14 illustrate examples for explaining a PBCH mapping scheme according to another embodiment of the present invention.

15 and 16 illustrate examples for explaining a PBCH mapping scheme according to another embodiment of the present invention.

17 and 18 are diagrams illustrating other examples for describing a PBCH mapping scheme according to another embodiment of the present invention.

19 is a diagram for explaining a DMRS pattern according to another embodiment of the present invention.

20 and 21 are diagrams for describing examples of the PBCH mapping scheme according to another embodiment of the present invention.

22 is a diagram for explaining an example of the PBCH mapping scheme according to another embodiment of the present invention.

23 is a diagram illustrating an information transmission apparatus for performing embodiments according to the present invention.

24 is a diagram for explaining an information transmission method performed by the apparatus of FIG. 23 according to the present invention.

25 is a diagram illustrating an information receiving apparatus for performing embodiments according to the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to that other component, but there may be another configuration between each component. It is to be understood that the elements may be "connected", "coupled" or "connected".

1 is a diagram illustrating a communication system to which embodiments of the present invention are applied.

Communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.

Referring to FIG. 1, a communication system includes a user equipment (UE) 10 and a transmission point 20 that performs uplink and downlink communication with the terminal 10.

In the present specification, a terminal 10 or a user equipment (UE), a receiving end is a comprehensive concept of a user terminal in wireless communication, and a mobile station (MS) in GSM as well as a UE in WCDMA and LTE, HSPA, etc. It should be interpreted as a concept that includes a user terminal (UT), a subscriber station (SS), a wireless device, and the like.

The transmitting end 20 or cell generally refers to a station communicating with the terminal 10, and includes a base station, a node-B, an evolved node-B, and a base transceiver. Other terms may be referred to as a system, an access point, a relay node, and a radio unit (RU).

In the present specification, the transmission terminal 20 or a cell should be interpreted in a comprehensive sense indicating a part of a region covered by a base station controller (BSC) in a CDMA, a NodeB of a WCDMA, etc., and a radio remote connected to a base station. All types of communication with one terminal such as head, relay node, sector of macro cell, site, other femtocell, picocell, micro cell such as RU (Radio Unit) Used as a generic concept to mean a device.

Although one terminal 10 and one transmission terminal 20 are shown in FIG. 1, the present invention is not limited thereto. It is possible for one transmission terminal 20 to communicate with the plurality of terminals 10, and one terminal 10 may communicate with the plurality of transmission terminals 20.

There are no limitations to the multiple access scheme applied to a communication system, and the present invention provides the code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), and OFDM. Applicable to various multiple access schemes such as FDMA, OFDM-TDMA, and OFDM-CDMA.

In addition, the present invention is a combination of the TDD (Time Division Duplex) method is transmitted using a different time, uplink transmission and downlink transmission, FDD (Frequency Division Duplex) method is transmitted using a different frequency, combining the TDD and FDD Applicable to hybrid duplexing method.

Specifically, embodiments of the present invention are applicable to asynchronous wireless communication that evolves into Long Term Evolution (LTE) and LTE-advanced through GSM, WCDMA, HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. Can be. The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be interpreted as including all technical fields to which the spirit of the present invention can be applied.

The transmitting end 20 performs downlink transmission to the terminal 10. The transmitter 20 may transmit a physical downlink shared channel (PDSCH), which is a main physical channel for unicast transmission in a legacy carrier type (LCT). In addition, the transmitting end 20 grants scheduling control for transmission on downlink control information such as scheduling required for reception of the PDSCH and uplink data channel (for example, a physical uplink shared channel (PUSCH)). Physical Downlink Control Channel (PDCCH) for transmitting information, Physical Control Format Indicator Channel (PCFICH) for transmitting an indicator for distinguishing regions of PDSCH and PDCCH, uplink transmission A control channel such as a physical HARQ indicator channel (PHICH) for transmitting a HARQ (Hybrid Automatic Repeat reQuest) confirmation may be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

   However, the transmitter 20 may transmit a physical downlink control channel (PDCCH), a physical control format indicator channel for transmitting an indicator for distinguishing the PDSCH and PDCCH regions in a new carrier type (NCT). A control channel such as a physical HARQ indicator channel (PHICH) for transmitting an indicator channel (PCFICH) and a hybrid automatic repeat request (HARQ) confirmation for uplink transmission will not be transmitted.

The transmitter 20 transmits a Cell-Specific Reference Signal (CRS), an MBSFN Reference Signal (MBSFN-RS), a UE-Specific Reference Signal in the downlink of the LCT. The UE-Specific Reference Signal (DMRS), Positioning Reference Signal (PRS), and Channel State Information Reference Signal (CSI-RS) may be transmitted.

CRS, a cell-specific RS, is a cell-specific reference signal transmitted over the entire band, and DM-RS is a unicast transmission for each UE. A UE-specific reference signal is defined in a band in which a physical downlink shared channel (PDSCH), which is a main physical channel, is transmitted. The cell specific reference signal means that the shape of a reference signal (for example, CRS) transmitted to each terminal in the same cell may be the same regardless of the terminal. The UE-specific reference signal (UE specific reference signal) means that the shape of the reference signal (for example, DM-RS) transmitted to each terminal may be different for each terminal.

The UE-specific reference signal (DM-RS) is a UE in an environment using a precoding scheme in which the transmitter 20 precodes a complex symbol using a precoding matrix before transmitting the complex symbol. Alternatively, it is a reference signal transmitted for the purpose of supporting the receiving end 10 to learn information about a virtual channel modified by precoding.

The DM-RS, which is a UE-specific reference signal, is transmitted for a band where each terminal receives a PDSCH, and each terminal receives channel or virtual channel information necessary for PDSCH decoding through the DM-RS reception. Acquire

In wireless communication, one radio frame (radioframe) consists of 10 subframes, and one subframe consists of two slots. The radio frame has a length of 10 ms and the subframe has a length of 1.0 ms. In general, the basic unit of data transmission is a subframe unit, and downlink or uplink scheduling is performed on a subframe basis.

One slot may have a plurality of OFDM symbols in the time domain and include at least one subcarrier in the frequency domain. For example, one slot contains seven OFDM symbols in the time domain (for Normal Cyclic Prefix or Normal CP) or six (for Extended Cyclic Prefix for Extended CP) and in the frequency domain It may include 12 subcarriers. The time-frequency domain defined as one slot may be referred to as a resource block (RB), but is not limited thereto.

The resource element (RE) may consist of one OFDM symbol on the time axis and one subcarrier on the frequency axis. Thus, one resource block may include 7 × 12 resource elements (in case of normal CP) or 6 × 12 resource elements (in case of extended CP).

The transmitter 20 transmits a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) for synchronization with the base station and cell identification. In the following description, an SSS is allocated to at least one specific resource block (RB) in at least one subframe of one radio frame. In this case, the transmitter 20 may avoid side effects such as interference with LTE user equipment (UE) and setting of DM-RS (Demodulation Reference Signal) as described below. The position of the PSS / SSS for the asynchronous NCT, which is one of the CCs not including the control region, can be changed on the time (symbol) axis.

On the other hand, the transmitter 20 will not transmit a cell-specific reference signal (CRS) in the downlink of the NCT. Instead, the transmitter 20 may transmit a tracking reference signal (TRS). TRS is a kind of reduced CRS transmitted in 5ms period based on the antenna port 0 and Rel.8 sequence of the conventional CRS. The transmitter 20 may transmit a UE-Specific Reference Signal (DM-RS) and a Channel State Information Reference Signal (CSI-RS) in the NCT.

Therefore, as the CRS is not transmitted, basic demodulation may be performed based on the DMRS, and thus the position of the PSS / SSS may be moved to another OFDM symbol to solve the collision problem between the PSS / SSS and the DMRS. In addition, the PBCH transmission pattern based on DMRS will be described in detail below.

2 is a view for explaining a PBCH transport channel processing process, Figure 3 is a view for explaining the RS and PBCH transmission scheme.

2 and 3, one BCH transport block corresponding to the MIB is transmitted once every 40 ms. A 16-bit Cyclic Redundancy Check (CRC) is inserted for one BCH transport block, 1 / 3-bit rate tail biting convolutional coding is performed as channel coding, and coding bits are repeated. After rate matching is performed, QPSK modulation is performed on the BCH transport block scrambled bit by bit. Antenna mapping is then performed for the modulated BCH transport block, demultiplexed and mapped to the first subframe of each frame in four consecutive frames.

That is, in the case of a normal CP (Normal Cyclic Prefix), 1920 bits are divided and transmitted in four subframes on the center 6PRB, and in the case of an extended CP (Extended Cyclic Prefix), 1728 bits are transmitted on the center 6PRB. Transmit equally in frames.

Meanwhile, the PBCH is transmitted on the center 6PRB of the second slot of subframe 0 of each radio frame.

CRS, a cell-specific RS, is a cell-specific reference signal transmitted over the entire band, and DM-RS is a unicast transmission for each UE. A UE-specific reference signal is defined in a band in which a physical downlink shared channel (PDSCH), which is a main physical channel, is transmitted. The cell specific reference signal means that the shape of a reference signal (for example, CRS) transmitted to each terminal in the same cell may be the same regardless of the terminal. The UE-specific reference signal (UE specific reference signal) means that the shape of the reference signal (for example, DM-RS) transmitted to each terminal may be different for each terminal.

The UE-specific reference signal (DM-RS) is a UE in an environment using a precoding scheme in which the transmitter 20 precodes a complex symbol using a precoding matrix before transmitting the complex symbol. Alternatively, it is a reference signal transmitted for the purpose of supporting the receiving end 10 to learn information about a virtual channel modified by precoding.

The DM-RS, which is a UE-specific reference signal, is transmitted for a band where each terminal receives a PDSCH, and each terminal receives channel or virtual channel information necessary for PDSCH decoding through the DM-RS reception. Acquire

4 is a diagram illustrating a cell access procedure to which an embodiment of the present invention is applied.

The UE is not only connected to the system for the first time, but also a plurality of elements merged through a handover for supporting cell reselection and mobility, and carrier aggregation (CA). The cell access procedure is also performed to find synchronization for carriers (Component Carrier (CC), hereinafter referred to as 'CC').

The cell search process includes PSS detection (S401) and SSS detection (S403) for acquiring frequency and symbol synchronization for a cell, thereby acquiring frame / slot synchronization of the cell and determining a cell ID. In the NCT, this process may be performed in parallel with the PSS / SSS or through another signal (S402).

After acquiring the cell synchronization and determining the cell ID, a step (S405) of checking whether the corresponding cell is an NCT or an LCT is performed and the TRS is checked (S407). Accordingly, the RRM measurement (S409) or the PBCH channel demodulation (S411) is performed. Is performed. As described above, when the CRS is not transmitted, PBCH channel demodulation is performed based on the DMRS.

Therefore, PSS / SSS detection and PBCH detection are the basis in the cell access process according to the cell search.

In order to avoid collision between the PSS / SSS and the DMRS, the position of the PSS / SSS may be moved on the time axis or DMRS puncturing may be performed.

However, in the case of PBCH estimating a channel based on the DMRS when the DMRS is punctured, this may cause a channel estimation error. In particular, such a channel estimation error may be serious for a terminal moving at a high speed. One way to solve this channel estimation error may be a method of changing the PBCH channel mapping position on the time axis.

Hereinafter, examples of PBCH transmission patterns according to whether or not to move to another OFDM symbol position and DMRS puncturing and other DMRS patterns in order to avoid collision with DMRS when PSS / SSS is present in the NCT will be described in detail.

In the following drawings, although not shown in the drawings, the pattern forms in subframe # 0 may appear the same in subframe # 5.

5 and 6 illustrate examples for explaining a PBCH mapping scheme according to an embodiment of the present invention.

Referring to FIG. 5, in order to alleviate a channel estimation error due to DMRS puncturing in a situation where the position of the PSS / SSS is not changed in the general CP of the FDD, the position of the PBCH is moved to another OFDM symbol on the time axis, and the PBCH channel In the mapping, a DMRS antenna port group (eg, a DMRS antenna port group that uses the same physical resource but distinguishes each other by a code) while maintaining 1920 _bits , which is an existing number of encoded bits transmitted on a PBCH (M _bit ), remains as it is. For example, the DMRS resource element may be transmitted using only the DMRS antenna port group # 1 (7, 8, 11, 13) and the group # 2 (9, 10, 12, 14).

That is, the left subframe of the figure is an example of the PBCH mapping method when the DMRS resource element is transmitted using only the antenna port 7/8, and the right subframe of the figure transmits the DMRS resource element using only the antenna port 9/10. This is an example of a PBCH mapping scheme.

In this case, a somewhat limited number of DMRS resource elements may be used due to the use of a limited number of DMRS antenna port groups.

Referring to FIG. 6, in the situation where the position of the PSS / SSS is not changed in the general CP of FDD, the position of the PBCH is shifted to another OFDM symbol on the time axis, and is the number of existing coded bits (M _bits ) transmitted on the PBCH. Although 1920bit is increased to 2016bit, DMRS resource elements can be transmitted using only one DMRS antenna port group without assuming TRS transmission.

The left subframe of the figure is an example of the PBCH mapping method when only the antenna port 7/8 is used for DMRS resource element transmission, and the right subframe of the figure is the PBCH when only the antenna port 9/10 is used for DMRS resource element transmission. This is an example of a mapping method.

In this case, a somewhat limited number of DMRS resource elements may be used due to the use of a limited number of DMRS antenna port groups.

7 is another example for explaining a PBCH mapping scheme according to an embodiment of the present invention.

Referring to FIG. 7, in a situation where the position of PSS / SSS is not changed in a general CP of FDD, the position of PBCH is shifted to another OFDM symbol on a time axis, and according to the PBCH mapping scheme shown in the left subframe of the figure, PBCH The existing number of coded bits (M _bits ) transmitted over a 1920 _bit to 1632 _bits is reduced, but DMRS resource elements can be transmitted using two DMRS antenna port groups ( DMRS antenna ports 7,8,9,10).

According to the PBCH mapping scheme shown in the left subframe of the figure, a somewhat smaller number of coded bits are transmitted on the PBCH channel, while using two DMRS antenna port groups ( DMRS antenna ports 7, 8, 9, 10). More DMRS resource elements may be available, which may benefit from channel estimation performance.

According to the PBCH mapping scheme of the right subframe of the figure, the number of existing coded bits (M _bits ) transmitted on the PBCH is reduced from 1920bit to 1728bit, but can be transmitted on the PBCH by not transmitting the TRS in the subframe in which the PBCH is transmitted. The number of coding bits can be increased. Accordingly, coding performance gain can be obtained on the PBCH channel.

8 is a diagram illustrating another example for explaining a PBCH mapping scheme according to an embodiment of the present invention. 8 shows examples of a case where the position of the PSS / SSS is not changed in the extended CP of the FDD and the position of the PBCH is moved to another OFDM symbol on the time axis.

According to the left subframe of the figure, the number of encoded bits transmitted on the PBCH may be increased to 1824 bits through rate matching processing with respect to the existing 1728 bits, thereby optimizing PRSCH mapping based on DMRS.

According to the right subframe of the figure, when the TRS is not transmitted in the subframe in which the PBCH is transmitted, the number of encoded bits transmitted on the PBCH may be increased from the existing 1728 bit to 1920 bits. Therefore, coding performance gain can be obtained on the PBCH channel.

9 and 10 correspond to the examples described with reference to FIGS. 5 through 8, in the case of the general CP in the TDD, the location of the PSS / SSS is the existing Rel. 8 is a diagram for describing a method of mapping PBCH in a situation of maintaining the same position as 8.

Referring to FIG. 9, in order to avoid collision of PSS / SSS and DMRS in the center 6PRB of subframe 0 in which PBCH is transmitted in TDD, DMRS is punctured as shown in FIG. An example of a PBCH mapping scheme that can be shown.

The left subframe of the figure uses all of the DMRS antenna ports, and the number of coding bits can be reduced from the existing 1920 bits to 1536 bits. On the right side of the diagram, the PBCH mapping method when the DMRS antenna ports are limited to 7, 8 As an example, the number of encoded bits may be reduced from the existing 1920 bits to 1824 bits.

On the other hand, when DMRS antenna ports 9 and 10 are used, the resource element directly below the frequency axis of the resource element used for DMRS transmission in the right subframe of the drawing is a resource element for transmitting DMRS (Rel-10 DMRS ports 9 and 10). As a resource element for PBCH is allocated to a resource element other than the resource element used for DMRS transmission, the PBCH may be mapped similarly to the right side of the drawing.

Referring to FIG. 10, in the situation where the position of the PSS / SSS is not changed in the general CP of the TDD, when the DMRS resource element is transmitted using two or one DMRS antenna port group without assuming TRS transmission, the PBCH Examples of mappings are shown.

The left subframe of the figure is an example of a PBCH mapping method in which two antenna port groups are used for DMRS resource element transmission. The number of bits transmitted on the PBCH is reduced from 1920 _bits , which is an existing coded bit, to 1728 _bits . Since the TRS is not transmitted to the subframe in which the PBCH is transmitted, the number of coding bits that can be transmitted on the PBCH can be increased as compared with the example described with reference to the left subframe of FIG. 9.

The right subframe of the figure is an example of a PBCH mapping method in which only antenna ports 7/8 are used for DMRS resource element transmission. The number of bits transmitted on the PBCH is increased from 1920 _bits , which is the existing number of encoded bits (M _bits ), to 2016 _bits . Can be.

On the other hand, when only antenna port 9/10 is used for DMRS resource element transmission in the right subframe of the figure, PRSCH is used for resource element except for resource element through which the corresponding DMRS antenna port 9/10 is used. Similarly (ie, using the OFDM symbol index used to transmit the PBCH in the right subframe of FIG. 10), the PBCH is mapped.

FIG. 11 is a diagram illustrating another example for describing a PBCH mapping scheme according to an embodiment of the present invention. FIG. FIG. 11 corresponds to the description of the extended CP of the FDD of FIG. 8, and is an example in which the position of the PSS / SSS is not changed in the TDD.

According to the left subframe of the figure, the number of coded bits transmitted on the PBCH can be maintained to be the same through rate matching processing for the existing 1728 bits, thereby optimizing PRSCH mapping based on DMRS.

According to the right subframe of the figure, when the TRS is not transmitted in the subframe in which the PBCH is transmitted, the number of encoded bits transmitted on the PBCH may be increased from the existing 1728 bit to 1920 bits. Therefore, coding performance gain can be obtained on the PBCH channel. 12 is a diagram for explaining a DMRS pattern according to another embodiment of the present invention.

Referring to FIG. 12, a DMRS pattern as shown in FIG. 12 may be considered to avoid collision between the PSS / SSS and the DMRS on the NCT in the center 6PRB of subframe 0 in which the PBCH is transmitted in FDD. In the drawings, examples of general and extended CPs are shown.

Referring to the figure, it is possible to change the position of the OFDM symbol in which the DMRS is transmitted on the time axis. The left subframe of the figure is for a normal CP (each slot is composed of seven symbols), and DMRS is assigned to the third and fourth OFDM symbols of the first and second slots of subframes # 0 and # 5 within each radio frame. An example of transmitting a DMRS resource element using two DMRS antenna port groups is shown.

In addition, the right side of the drawing is for an extended CP (each slot consists of six symbols), in which a DMRS is allocated to the second and third symbols of the first and second slots of subframe # 0 in each radio frame, and one DMRS is assigned. An example of transmitting a DMRS resource element using only an antenna port group is shown.

When such a new DMRS pattern is applied on the NCT, various PBCH mapping schemes based on DMRS can be applied accordingly. 13 and 14 illustrate examples for explaining a PBCH mapping scheme according to another embodiment of the present invention. The examples illustrate the general CP of FDD.

According to the new DMRS pattern according to another embodiment of the present invention described with reference to the left subframe of FIG. 12, the position on the time axis of the DMRS may be changed, and accordingly, the position on the time axis of the PBCH may be changed. Here, examples of transmitting DMRS resource elements using only two DMRS antenna port groups are shown.

Accordingly, in the left subframe of FIG. 13 (that is, subframes # 0 and # 5), PBCHs are included in the second through fifth symbols of the second slot as the DMRSs are located in the third and fourth symbols of the first and second slots. An example of mapping is shown, and an example in which a PBCH is mapped to second to fifth symbols of a first slot is illustrated in a right subframe of FIG. 13.

In this case, the number of coding bits that can be transmitted on the PBCH is reduced from the existing 1920bits to 1632bits, while more DMRS resource elements transmitted using two antenna groups can be used, which may have a gain in channel estimation performance.

According to the PBCH mapping method of Figure 14, the same as the left and right sub-frames DMRS pattern and its left and right sub-frames in FIG. 13 PBCH mapping position are each in accordance with the, and the number of encoded bits transmitted on the PBCH (M _bit) is The number of coding bits that can be transmitted on the PBCH can be increased by reducing the conventional 1920 bits to 1728 bits but not transmitting the TRS in the subframe in which the PBCH is transmitted. Accordingly, coding performance gain can be obtained on the PBCH channel.

15 and 16 illustrate examples for explaining a PBCH mapping scheme according to another embodiment of the present invention. These examples describe the extended CP of FDD.

According to the new DMRS pattern according to another embodiment of the present invention described with reference to the right subframe of FIG. 12, the position on the time axis of the DMRS may be changed, and accordingly, the position on the time axis of the PBCH may be changed. In addition, the DMRS resource element may be transmitted using only one DMRS antenna port group.

In the left subframe of FIG. 15, an example in which PBCH is mapped to the first to fourth symbols of the second slot is shown as DMRS is located in the second and third symbols of the first and second slots. In the subframe, an example in which the PBCH is mapped to the first to fourth symbols of the first slot is shown.

In this case, the number of coding bits that can be transmitted on the PBCH is reduced from the existing 1920 bits to 1728 bits.

The PBCH mapping scheme of FIG. 16 is a method applicable when the DMRS pattern is changed as shown in the right subframe of FIG. 12. As the DMRS is located in the second and third symbols of the first and second slots, the DMRS PBCH channels may be mapped to neighboring symbols on the left and right sides of an OFDM symbol to which DMRSs are allocated for both the first and second slots to which Ms are allocated.

Accordingly, the number of encoded bits M _bits transmitted on the PBCH can be maintained at 1920 _bits .

17 and 18 are diagrams illustrating other examples for explaining a PBCH mapping scheme according to another embodiment of the present invention and correspond to a case of an extended CP in FDD.

In FIG. 17, DMRS is transmitted in the same pattern as the example described with reference to FIG. 15, and the PBCH mapping scheme is the same, but the TRS may not be transmitted on the subframe in which the PBCH is transmitted. Accordingly, the number of encoded bits that can be transmitted on the PBCH may be maintained at the existing 1920 bits and may increase as compared with 1728 bits according to FIG. 15.

FIG. 18 may be configured such that DMRS is transmitted in the same pattern as the example described in FIG. 16 and the PBCH mapping scheme is the same, but TRS is not transmitted on the subframe in which the PBCH is transmitted. Accordingly, the number of coded bits that can be transmitted on the PBCH may increase from 2,920 bits to 2304 bits, and thus, more coding bits than 1728 bits according to FIG. 16 may be transmitted on the PBCH, thereby obtaining additional coding performance gains.

Referring to the examples described in the embodiments of the present invention, in the case of a general CP or an extended CP in TDD, the PBCH mapping method according to the examples described with reference to FIGS. 12 to 18 may be similarly applied.

19 is a diagram for explaining a DMRS pattern according to another embodiment of the present invention.

Referring to the drawings, in order to avoid collision between the PSS / SSS and the DMRS on the NCT in the center 6PRB of subframe 0 in which the PBCH is transmitted in FDD, a DMRS pattern may be considered. An example of a general CP is illustrated in the left subframe of the figure, but an example of an extended CP is illustrated in the right subframe, but is not limited thereto.

Referring to the figure, it is possible to change the position of the OFDM symbol in which the DMRS is transmitted on the time axis. The left subframe of the figure shows an example in which DMRS is allocated to the first and second OFDM symbols of the first and second slots of the subframe and transmits a DMRS resource element using two DMRS antenna port groups. In addition, the right subframe of the figure shows an example of allocating DMRS to the second and third symbols of the first and second slots of the subframe and transmitting the DMRS resource element using only one antenna group.

When such a new DMRS pattern is applied on the NCT, various PBCH mapping schemes based on DMRS can be applied accordingly.

20 and 21 are diagrams for describing examples of the PBCH mapping scheme according to another embodiment of the present invention. Although the examples describe the general CP of the FDD, the extended CP can be similarly applied to the examples described with reference to FIGS. 15 to 18.

According to a new DMRS pattern according to another embodiment of the present invention described with reference to the left subframe of FIG. 19, the position on the time axis of the DMRS may be changed, thereby changing the position on the time axis of the PBCH. Here, examples of transmitting DMRS resource elements using only two antenna groups are shown.

Accordingly, the left subframe of FIG. 20 shows an example in which the PBCH is mapped to the first to fourth symbols of the first slot as DMRSs are located in the first and second symbols of the first and second slots. An example in which a PBCH is mapped to first to fourth symbols of a second slot in a frame is shown.

In this case, the number of coding bits that can be transmitted on the PBCH is reduced from the existing 1920 bits to 1632 bits, while more DMRS resource elements transmitted using two antenna groups can be used, which may have a gain in channel estimation performance.

On the other hand, the pattern shown in the right subframe may be efficient for interference cancellation (ICIC) with the control region of the LCT in the adjacent base station.

According to the PBCH mapping method of Figure 21, the same as the left and right sub-frames DMRS pattern and its left and right sub-frames in FIG. 20 PBCH mapping position are each in accordance with the, and the number of encoded bits transmitted on the PBCH (M _bit) is The number of coding bits that can be transmitted on the PBCH can be increased by reducing the conventional 1920 bits to 1728 bits but not transmitting the TRS in the subframe in which the PBCH is transmitted. Accordingly, coding performance gain can be obtained on the PBCH channel.

Meanwhile, in case of the extended CP of FDD, the PBCH channel mapping scheme described with reference to FIGS. 13 to 18 may be similarly applied.

FIG. 22 is a diagram illustrating still another example of PBCH mapping according to another embodiment of the present invention, in which a position of a PSS / SSS is not changed with respect to a general CP of TDD, and a DMRS resource element is used using two antenna port groups. Examples of transmitting.

According to the left subframe of the figure, the number of encoded bits transmitted on the PBCH is reduced from the existing 1920 bits to 1632 bits.

According to the right subframe of the figure, when the TRS is not transmitted in the subframe in which the PBCH is transmitted, the number of encoded bits transmitted on the PBCH may be increased from the existing 1920 bits to 2016 bits. Therefore, coding performance gain can be obtained on the PBCH channel.

Meanwhile, in case of an extended CP of TDD, the PBCH mapping method described with reference to FIGS. 15 to 18 may be similarly applied.

23 is a diagram illustrating a base station as an apparatus for performing embodiments according to the present invention.

The base station 500 includes a receiver 510, a controller 520, and a transmitter 530.

The controller 520 controls the overall operation of the base station to perform the operations required to perform the embodiments of the present invention described above with reference to FIGS. 5 to 21.

The transmitter 530 and the receiver 510 transmit and receive signals, messages, or data necessary for performing the above-described embodiments of the present invention with the terminal 10.

The base station 500 described with reference to FIG. 23 performs a process to be described later through the receiver 510, the controller 520, and the transmitter 530 to allocate DMRS according to embodiments of the present invention, and to map PBCH accordingly. One downlink transmission signal is transmitted to the terminal.

24 is a diagram for explaining a PBCH transmission method performed by the apparatus of FIG. 23 according to the present invention.

The base station 500 scrambles one input BCH transport block (S610).

That is, the _bits of one BCH transmission bit block b (0),..., B (M _bit- 1) determined according to the M _bit value are transmitted as input bits to scramble. Here, the number of coding bits (M _bits ) transmitted on the PBCH is determined according to the PBCH mapping method described above in the embodiments of the present invention. The determined value is equal to the value E of the final number of bits according to rate matching processing.

[Equation 1]

Where the scramble sequence c (i) is in each radio frame that satisfies n _f mod4 = 0

Is initialized to

Subsequently, the base station performs QPSK modulation on the scrambled value (S620). Accordingly, the symbols d (0),..., D (M _symb −1) are output.

Layer mapping and precoding are performed (S630). That is, the modulated symbol blocks d (0), ..., d (M _symb -1) are DMRS ports.

Are mapped to each layer by applying the DMRS port

Precoded vector block by applying

, i = 0, ..., M _symb -1 is printed.

Where y ^(p) (i) represents the signal for antenna port p, and when the number of antenna ports is 1, one of all possible or some DMRS antenna ports, e.g. 7, 8, 9, or 10 Antenna ports may be used. In addition, when the number of antenna ports is 2, two antenna ports of all or some possible DMRS antenna ports, for example, 7 and 8, 9 and 10, 7 and 9, etc. may be used. And when the number of antenna ports is 4, all or some DMRS antenna ports possible, for example p = 7,8,9 and 10 or p = 7,8,11 and 13 or p = 9,10,12 and 14 Four antenna ports can be used.

Subsequently, the base station 500 maps resource elements (S640).

According to one example of resource element mapping, at each antenna port, at least one complex symbol block y ^(p) (0), ..., y ^(p) (M _symb -1) satisfies n _f mod4 = 0 There is a radio frame, which is transmitted over four consecutive radio frame intervals including the radio frame, starting from y (0) and mapped to (k, l) resource elements in order.

In this case, the PBCH resource element is mapped only to (k, l) resource elements that are not allocated for reference signal transmission, and ascends to index k first in slot X of subframe 0 or subframe 0 for 4 radio frames. It can be mapped in increasing order, then in ascending order for index l, and finally increasing the number of frames. The index k is shown in Equation 2 below.

[Equation 2]

Where k is the frequency index, l is the OFDM symbol index on which the PBCH is transmitted, n is the first OFDM symbol index on which the PBCH is transmitted in the subframe in which the PBCH is transmitted or in one slot in the subframe, and is allocated for the reference signal. Resource elements are excluded.

The mapping operation is performed under the assumption that there is a terminal specific reference signal of antenna port 7-Y (= 8, 10 or 14) regardless of the actual implementation.

According to another example of resource element mapping, the resource element index when the PBCH mapping is not continuous is expressed by Equation 3 below.

That is, in ascending order for index k in slots 0 and 1 of subframe 0 of 4 radio frames for (k, l) resource elements not allocated for reference signal transmission, ascending order for index l You can map this by increasing the number of frames and finally increasing the number of frames. The resource element index is shown in Equation 2 below.

[Equation 3]

Where k is the frequency index, l is the OFDM symbol index for the PBCH, n is the first OFDM symbol index on which the PBCH is transmitted in a subframe or one slot in the subframe, and the resource element allocated for the reference signal is excluded. do.

The mapping operation is performed under the assumption that there is a terminal specific reference signal of antenna port 7-Y (= 8, 10 or 14) regardless of the actual implementation.

25 is a diagram illustrating a terminal as an apparatus for performing embodiments according to the present invention.

The terminal 700 includes a receiver 710, a controller 720, and a transmitter 730.

The controller 720 controls the overall operation of the terminal 700 to perform an operation necessary to perform the embodiments of the present invention described above with reference to FIGS. 5 to 21.

The transmitter 730 and the receiver 710 transmit and receive signals, messages or data necessary for performing the above-described embodiments of the present invention with the base station 20 or 500. In particular, the receiver 710 receives a downlink transmission signal from the base station 20 or 500 under the control of the controller 720 to detect the PSS / SSS, and detects a demodulation reference signal (DMRS) based thereon. A physical broadcast channel (PBCH) may be searched for a blind search. Accordingly, the controller 720 may extract a master information block (MIB) through the searched PBCH. Embodiments have been described above with reference to the drawings, but the present invention is not limited thereto.

In the above described the method of the embodiments of the present invention according to the steps shown in the accompanying drawings, this is for convenience of description only, each step according to the implementation manner within the scope not departing from the essential concept of the invention The procedure of performing may be changed, two or more steps may be integrated, or one step may be performed separately in two or more steps.

In the above description, all elements constituting the embodiments of the present invention are described as being combined or operating in combination, but the present invention is not necessarily limited to the embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more. In addition, although all of the components may be implemented in one independent hardware, each or all of the components may be selectively combined to perform some or all functions combined in one or a plurality of hardware. It may be implemented as a computer program having a. Codes and code segments constituting the computer program may be easily inferred by those skilled in the art.

Such a computer program may be stored in a computer readable storage medium and read and executed by a computer, thereby implementing embodiments of the present invention. The storage medium of the computer program may include a magnetic recording medium, an optical recording medium, and the like.

In addition, the terms "comprise", "comprise" or "having" described above mean that the corresponding component may be included, unless otherwise stated, and thus excludes other components. It should be construed that it may further include other components instead. All terms, including technical and scientific terms, have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms commonly used, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be construed in an ideal or excessively formal sense unless explicitly defined in the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims priority pursuant to United States Patent Act Section 119 (a) (35 USC § 119 (a)) of Patent Application No. 10-2012-0149945, filed with Korea on 20 December 2012. All content is incorporated by reference in this patent application. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims (16)

1. Scramble is performed for one PBCH transmission bit block including the number of bits corresponding to the number of coding bits M _{bits to} be transmitted on a physical broadcast channel (PBCH), and QPSK Performing quadrature phase-shift keying modulation and layer mapping and precoding; and

   There is at least one radio frame in which radio frame index n _f satisfies n _f mod4 = 0, and for four consecutive radio frames including the radio frame, a complex symbol block y ^(p) ( 0), ..., y ^(p) subframe 0 or subframe 0 of the four radio frames for (k, l) resource elements not allocated for reference signal transmission among (M _symb- 1) Mapping each bit of the precoded PBCH transmission bit block by increasing frequency index k, increasing OFDM symbol index l, and increasing index n _f of the radio frame, in ascending order in a specific slot; Information transmission method of a base station comprising a.
2. The method of claim 1,

   The indexes k and l satisfy the following equation,

   

   Where n is the first OFDM symbol index of the PBCH transmission bit block within the subframe,

   

   Is the downlink bandwidth,

   

   The information transmission method of the base station characterized in that the resource block size in the frequency domain.
3. The method of claim 1,

   The indexes k and l satisfy the following equation,

   

   Where n is the first OFDM symbol index of the PBCH transmission bit block in the subframe,

   

   Is the downlink bandwidth,

   

   The information transmission method of the base station characterized in that the resource block size in the frequency domain.
4. The method of claim 1,

   The reference signal is a demodulation reference signal (DMRS), and the DMRS is transmitted through one of the antenna port, one or two or four information transmission method of the base station.
5. Scramble is performed for one PBCH transmission bit block including the number of bits corresponding to the number of coding bits M _{bits to} be transmitted on a physical broadcast channel (PBCH), and QPSK (Quadrature phase-shift keying) modulation and layer mapping and precoding, at least one radio frame in which the radio frame index n _f satisfies n _f mod4 = 0, and the radio In four consecutive radio frames, including frames, one of the complex symbol blocks y ^(p) (0), ..., y ^(p) (M _symb -1) at each antenna port is not allocated for reference signal transmission. By increasing the frequency index k, increasing the OFDM symbol index l, increasing the index n _f of the radio frame in ascending order in a specific slot of subframe 0 or subframe 0 for the (k, l) resource elements , remind A controller for mapping each bit of the pre-coded PBCH transmission bit block; and

   And a transmitter for transmitting a master information block (MIB) through the mapped PBCH channel.
6. The method of claim 5,

   The indexes k and l satisfy the following equation,

   

   Where n is the first OFDM symbol index of the PBCH transmission bit block in the subframe,

   

   Is the downlink bandwidth,

   

   Is a base station, characterized in that the resource block size in the frequency domain.
7. The method of claim 5,

   The indexes k and l satisfy the following equation,

   

   Where n is the first OFDM symbol index of the PBCH transmission bit block in the subframe,

   

   Is the downlink bandwidth,

   

   Is a base station, characterized in that the resource block size in the frequency domain.
8. The method of claim 5,

   The reference signal is a demodulation reference signal (DMRS), the DMRS is characterized in that the base station transmits through one of one, two or four antenna ports.
9. Searching for a physical broadcast channel (PBCH) based on a demodulation reference signal (DMRS) and extracting a master information block (MIB) transmitted through the PBCH; and,

   In the PBCH search, there is at least one radio frame whose radio frame index n _f satisfies n _f mod4 = 0, and for each of four consecutive radio frames including the radio frame, a complex symbol at each antenna port Subframes of the four radio frames for (k, l) resource elements not allocated for reference signal transmission among blocks y ^(p) (0), ..., y ^(p) (M _symb -1) Retrieving each bit of the PBCH transmission bit block by increasing the frequency index k, increasing the OFDM symbol index l, and increasing the index n _f of the radio frame, in ascending order in a particular slot of subframe 0 or subframe 0; Information receiving method of the terminal characterized in that.
10. The method of claim 9,

    The indexes k and l satisfy the following equation,

    

    Where n is the first OFDM symbol index of the PBCH transmission bit block within the subframe,

    

    Is the downlink bandwidth,

    

    The information receiving method of the terminal, characterized in that the resource block size in the frequency domain.
11. The method of claim 9,

    The indexes k and l satisfy the following equation,

    

    Where n is the first OFDM symbol index of the PBCH transmission bit block in the subframe,

    

    Is the downlink bandwidth,

    

    The information receiving method of the terminal, characterized in that the resource block size in the frequency domain.
12. The method of claim 9,

    The reference signal is a demodulation reference signal (DMRS), and the DMRS is a method of receiving information, characterized in that transmitted through one of one, two or four antenna ports.
13. A receiving unit searching for a physical broadcast channel (PBCH) based on a demodulation reference signal (DMRS) and extracting a master information block (MIB) transmitted through the PBCH; and,

    The receiving unit, in the PBCH search, has a radio frame index n _f

    

    There is at least one radio frame that satisfies, and for four consecutive radio frames including the radio frame, a complex symbol block y ^(p) (0), ..., y ^(p) at each antenna port Frequency index k in ascending order in a specific slot of subframe 0 or subframe 0 of the 4 radio frames for (k, l) resource elements not allocated for reference signal transmission among (M _symb- 1). And search each bit of the PBCH transmission bit block by increasing the OFDM symbol index l and increasing the index n _f of the radio frame.
14. The method of claim 13,

    The indexes k and l satisfy the following equation,

    

    Where n is the first OFDM symbol index of the PBCH transmission bit block within the subframe,

    

    Is the downlink bandwidth,

    

    Is a resource block size in a frequency domain.
15. The method of claim 13,

    K and l satisfy the following equation,

    

    Where n is the first OFDM symbol index of the PBCH transmission bit block in the subframe,

    

    Is the downlink bandwidth,

    

    Is a resource block size in a frequency domain.
16. The method of claim 13,

    The reference signal is a demodulation reference signal (DMRS), the terminal characterized in that the DMRS is transmitted through one of one, two or four antenna ports.

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