KR20090076752A - Method for Signaling P-BCH Boundary Information - Google Patents

Abstract

A method for signaling P-BCH(Physical-Broadcasting Channel) boundary information is provided to efficiently signal the P-BCH boundary information and enable a terminal to efficiently obtain the information. Phase modulation is performed to a synchronous channel. The phase-modulated synchronous channel is transmitted. The phase modulation of the synchronous channel has a modulation type corresponding to the number of P-BCH boundary information. Each modulation type is predetermined between a transmitting and a receiving terminal to be matched with the boundary information of the P-BCH.

Description

Signaling method for physical broadcast channel boundary information {Method for Signaling P-BCH Boundary Information}

The following description relates to mobile communication, and in particular, to a method for efficiently signaling physical broadcast channel (P-BCH) boundary information and for the terminal to efficiently obtain this information.

The following description can be applied to various mobile communication systems. However, for convenience of description, an example of the 3GPP LTE system will be described in detail.

P-BCH refers to a physical broadcast channel and may also be referred to as a primary broadcast channel in the art. In order to examine the necessity of boundary information of the P-BCH, a random access channel (RACH) will be described first.

A random access channel (RACH) is a random access channel through which user equipment (hereinafter referred to as "UE") performs downlink synchronization with a base station and finds base station information. The location of the channel and the like can be known from the base station information, and the RACH can be accessed without the UE synchronizing with the base station.

A physical layer channel for RACH transmission is called a PRACH, and the structure of the PRACH is shown in FIG.

1 illustrates a physical layer random access preamble structure.

의 순환 전치부(CP)와 길이

의 시퀀스부로 구성된다. 이와 같은 PRACH를 위한 파라미터 값들은 다음 표 1에 나타낸 바와 같으며, 이는 프레임 구조 및 임의접속 구성에 따라 결정된다. 아울러, PRACH 포맷은 상위 계층(Higher Layer)이 제어한다.Length as shown in FIG. 1

Circulation anterior teeth (CP) and length

It consists of a sequence section of. Parameter values for such a PRACH are as shown in Table 1 below, which is determined according to the frame structure and random access configuration. In addition, the PRACH format is controlled by a higher layer.

Preamble format

0 3152 * Ts 24576 * Ts One 21012 * Ts 24576 * Ts 2 6224 * Ts 2 * 24576 * Ts 3 21012 * Ts 2 * 24576 * Ts 4 (frame structure type 2 only) 0 * Ts 4096 * Ts

Here, Ts means a sampling period.

When the MAC layer triggers such random access preamble transmission, the random access preamble is limited to a certain time and frequency resource. For example, the following configuration is possible for the preamble formats 0 to 3.

PRACH configuration System frame number Subframe number 0 Even One One Even 4 2 Even 7 3 Any One 4 Any 4 5 Any 7 6 Any 1, 6 7 Any 2, 7 8 Any 3, 8 9 Any 1, 4, 7 10 Any 2, 5, 8 11 Any 3, 6, 9 12 Any 0, 2, 4, 6, 8 13 Any 1, 3, 5, 7, 9 14 Any 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 15 Even 9

The subframe numbers listed in Table 2 above indicate subframes in which random access preamble transmission is allowed in a given configuration. Accordingly, this may be referred to as a random access subframe (hereinafter, referred to as a "RA subframe"), and the PRACH configuration may be referred to as a random access slot configuration (RA slot configuration).

For the 16 configurations of Table 2, the random access period is as follows.

RA slot configuration RA period (sub-frames) RA sub-frames 0 20 One One 20 4 2 20 7 3 10 One 4 10 4 5 10 7 6 5 One 7 5 2 8 5 3 9 10 1, 4, 7 10 10 2, 5, 8 11 10 3, 6, 9 12 2 0 13 2 One 14 One 0 15 20 9

That is, 16 PRACH configurations of up to 20 ms random access period are defined in the 3GPP LTE system. Accordingly, the UE needs to know a PRACH frequency that allows RACH transmission in order to handover to a target cell.

Meanwhile, a 10 ms period and a 40 ms period are used in 3GPP LTE for the frequency hopping period of the PRACH. The 10 ms frequency hopping period can simplify the handover process, while adversely affecting the performance of the handover PRACH as well as other uses of the PRACH. Therefore, it is necessary to consider the 40 ms frequency hopping period, in which case it is required to obtain 40 ms P-BCH frame boundary information. This is described in detail in "RACH Frequency Hopping period of 10ms" (Document No. R1-080371, 3GPP TSG RAN WG1 # 51bis, LG Electronics Inc.).

However, when the UE acquires 40 ms P-BCH boundary information through blind decoding, there is a problem of increasing the complexity of the UE, and increases the handover (HO) interrupt time for handover. To increase the HO latency.

In order to solve the above problems, the present invention is to provide a method for efficiently signaling the P-BCH boundary information (PRACH transmission resource information), the terminal to efficiently obtain this information.

One object of the present invention for solving the above problems provides a method for signaling physical broadcast channel (P-BCH) boundary information. According to an embodiment therefor, the method includes performing phase modulation on a synchronization channel; And transmitting the phase modulated sync channel, wherein the phase modulation of the sync channel has a modulation form corresponding to the number of boundary information of the P-BCH, wherein each of the modulation forms is each of the P- channels. It is characterized in that it is predefined between the transmitting and receiving end to correspond to the boundary information of the BCH.

In addition, the number of P-BCH boundary information may be four, and the sync channel is preferably a sub-sync channel (S-SCH).

In addition, the phase modulation of the S-SCH may be performed as a QPSK modulation that modulates the entirety of the S-SCH to one of +1, + j, -1, and -j. Specifically, the four P-BCH The boundary information may be set to correspond to each of four modulation values of +1, + j, -1, and -j for the S-SCH.

In addition, the phase modulation of the S-SCH may be performed as a BPSK modulation that modulates +1 or -1 for the two codes SSC0 and SSC1 constituting the S-SCH, specifically, the four P- The BCH boundary information is assigned to four modulation value combinations of (+1. +1), (+1, -1), (-1, -1) and (-1, +1) for the SSC0 and the SSC1, respectively. Can be set to correspond. In this case, it is assumed that the modulation value for SSC0 is represented by x and y when the modulation value for SSC0 is y.

On the other hand, another aspect of the present invention for solving the above problems provides a method for acquiring physical broadcast channel (P-BCH) boundary information. A method according to an embodiment for this purpose includes receiving a synchronization channel to perform timing acquisition and cell ID search; And acquiring boundary information of the P-BCH through phase modulation information of the synchronization channel, wherein the phase modulation of the synchronization channel has a modulation form corresponding to the number of boundary information of the P-BCH, respectively. The modulation type of is characterized in that it is predefined between the transmitting and receiving end to correspond to the boundary information of each of the P-BCH.

In addition, a method for obtaining physical broadcast channel (P-BCH) boundary information according to another embodiment of the present invention includes: searching for time synchronization and three cell IDs through a main synchronization channel (P-SCH); Searching for 168 cell group IDs and 5 ms frame timing over an auxiliary synchronization channel (S-SCH); And acquiring boundary information of the P-BCH through phase modulation information of the auxiliary synchronization channel, wherein the phase modulation of the synchronization channel has a modulation form corresponding to the number of boundary information of the P-BCH. Each modulation type is characterized in that it is previously defined between the transmitting and receiving end to correspond to the boundary information of each of the P-BCH.

Finally, another aspect of the present invention provides a method for signaling a handover user equipment (UE) to obtain resource region information for random access channel transmission. The method includes performing phase modulation on a synchronization channel; And transmitting the phase modulated sync channel, wherein the phase modulation of the sync channel has a modulation form corresponding to the number of boundary information of a physical broadcast channel (P-BCH), each of the modulation forms being each In order to correspond to the boundary information of the P-BCH of the transmission and reception end is previously defined, the UE is characterized in that to obtain the resource region information for the random access channel transmission through the P-BCH.

According to the present invention as described above, it is possible to provide a method for efficiently signaling P-BCH boundary information (PRACH transmission resource information) and the terminal efficiently obtaining this information.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced.

The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, one of ordinary skill in the art appreciates that the present invention may be practiced without these specific details. In some instances, well-known structures and devices are omitted or shown in block diagram form, centering on the core functions of each structure and device, in order to avoid obscuring the concepts of the present invention. In addition, the same components will be described with the same reference numerals throughout the present specification.

As described above, the present invention is to provide a method for efficiently signaling P-BCH boundary information. To this end, in order to obtain PRACH transmission information, indirectly, there are three possible methods for signaling P-BCH boundary information: (1) a method of directly decoding a P-BCH, and (2) a reference signal (RS) period. Consider the method of extending to 40ms, and (3) the method of signaling P-BCH boundary information using phase modulation of the synchronization channel, respectively, and compared the other method with the third method proposed by the present invention. It will be described in more detail as.

Direct P- BCH How to decode

Blind decoding the P-BCH for the target cell provides the UE with RACH transmission timing information. However, blind decoding is required for four P-BCH TTIs corresponding to 40 ms in order to obtain coverage reliability. More specifically, reference is briefly made to the following simulation results disclosed in "Primary BCH performance; coverage and detection" (Document No. R1-072960, 3GPP TSG RAN WG1 # 49bis Meeting, Nokia Siemens Networks, Nokia).

Hereinafter, EUTRA simulations for the two cases for 3GPP (hereinafter referred to as "Case 1 and 3" for convenience) are considered for coverage performance check. Full load interference is generated except for the serving cell, and signal-to-interference statistics are collected for all UEs in the coverage area. P-BCH performance with respect to 1% P-BCH detection probability under various transmission diversity conditions and repetition coefficients is as follows.

Transmit diversity Code repetition factor # of soft combining Effective code rate Required G-factor [dB] for 1% detection threshold Percentile below 1% detection threshold Case 1 Case 3 1 Tx 2 One 1/6 -1.03 20.9 26.9 1 Tx 2 2 1/12 -4.07 3.5 7.9 1 Tx 2 3 1/18 -5.75 0.5 2.9 1 Tx 2 4 1/24 -7.10 0.0 1.2 1 Tx 3 4 1/36 -8.46 0.0 0.5 2 Tx SFBC 2 One 1/6 -2.61 10.0 15.8 2 Tx SFBC 2 2 1/12 -5.42 0.8 3.6 2 Tx SFBC 2 3 1/18 -7.15 0.0 1.2 2 Tx SFBC 2 4 1/24 -8.31 0.0 0.6 2 Tx SFBC 3 4 1/36 -9.92 0.0 0.2

In Table 4, the results of obtaining a coverage reliability of 98% or more are shown in bold type, and the results of obtaining a coverage freshness of 95% or more are shown in italics.

Through such simulation results, a low effective code rate is required to obtain 98% or more coverage reliability for 1% P-BCH detection probability. Such a low code rate can be achieved by the UE soft-combining the received P-BCH burst several times. In consideration of various cases, the UE may satisfy the reliability condition by combining the P-BCH received through the 4 P-BCH TTI having a length of 40 ms. For more details, refer to the R1-072960 document.

As such, decoding the P-BCH to obtain PRACH transmission timing may result in long handover interruption and is not appropriate. In addition, it may take longer than 40 ms to accumulate four P-BCH TTIs. An example of such a case will be described with reference to FIG.

FIG. 2 is a diagram for explaining an example in which a UE decodes a longer length P-BCH to accumulate four P-BCH TTIs.

Referring to the example of FIG. 2, in case the UE starts decoding the neighbor cell in the synchronization channel located at 5 ms, the decoding of the P-BCH starts from the second P-BCH TTI within the 40 ms P-BCH TTI. 65 ms TTI may be needed to accumulate P-BCH TTIs. This is because the information payload between P-BCH bursts at the boundary is different due to SFN change.

RS  Cycle 40 ms How to extend

By extending the period of the reference signal (hereinafter referred to as "RS") of the 3GPP LTE system from 10 ms to 40 ms, the UE can acquire the boundary information of the P-BCH. However, when the RS period is extended to 40 ms, the following problem may occur.

First, the extension of the RS period can affect the measurement of the UE. In the 3GPP LTE system, a frame forms a period of 10 ms, and the UE acquires such 10 ms frame boundary information through a cell search procedure. However, when the RS period is extended to 40 ms, since the UE has only 10 ms frame boundary information as described above, four ambiguities for the 40 ms period occur. This problem can affect the additional complexity and accuracy of the measurement.

Second, since the UE does not know the system bandwidth of the target cell, for 40 ms P-BCH boundary discovery, the UE will only use RS within 1.25 MHz in the first and second OFDM symbols in the SCH frame and each subframe. . That is, the use of RS for P-BCH boundary search may be limited.

Third, most basically searching for some information from the RS can increase the search error. The downlink RS is transmitted through an area defined by the 0th and 4th (or 3rd when using a long CP) OFDM symbol of every slot and every 6th subcarrier, and the search performance is determined by time selectivity and frequency selectivity (Time / May be degraded due to Frequency Selectivity). Under additional timing / frequency offset environments or high Doppler environments, search performance may be further degraded.

P-Phase Using Phase Modulation of Sync Channel BCH  Boundary information Signaling  Way

Accordingly, a preferred embodiment of the present invention proposes a method of signaling boundary information of a P-BCH using phase modulation of a synchronization channel, and thereby allowing a UE to acquire PRACH transmission information.

That is, when the base station transmits a synchronization channel in downlink, first, phase modulation may be performed on the synchronization channel signal so that each modulation value represents boundary information of the P-BCH. In this case, the phase modulation may predefine a modulation value corresponding to the number of P-BCH boundary information (for example, four), and may be set in advance so that each modulation type corresponds to each P-BCH boundary information. .

Hereinafter, a case of using phase modulation of a secondary synchronization channel (S-SCH) among the synchronization channels will be described.

When the 62 length sequence used for the S-SCH is represented by d (0), d (1), .., d (61), they can be seen as two 31 length binary sequences interleaved and connected. The concatenated sequence is scrambled by the scrambling sequence given by the main sync channel signal.

The combination of the two 31 length sequences defining the S-SCH signal is defined differently in slot 0 and slot 10 as follows.

으로부터 다음과 같이 유도될 수 있다.Here, n is an integer of 0 ≦ n ≦ 30, and slot 0 and slot 10 correspond to two slots through which the S-SCH is transmitted. In addition, the indexes m ₀ and m ₁ are physical layer cell ID groups

Can be derived as follows.

The result according to Equation 2 can be represented by the following table.

m ₀ m _One

m ₀ m _One

m ₀ m _One

m ₀ m _One

m ₀ m _One 0 0 One 34 4 6 68 9 12 102 15 19 136 22 27 One One 2 35 5 7 69 10 13 103 16 20 137 23 28 2 2 3 36 6 8 70 11 14 104 17 21 138 24 29 3 3 4 37 7 9 71 12 15 105 18 22 139 25 30 4 4 5 38 8 10 72 13 16 106 19 23 140 0 6 5 5 6 39 9 11 73 14 17 107 20 24 141 One 7 6 6 7 40 10 12 74 15 18 108 21 25 142 2 8 7 7 8 41 11 13 75 16 19 109 22 26 143 3 9 8 8 9 42 12 14 76 17 20 110 23 27 144 4 10 9 9 10 43 13 15 77 18 21 111 24 28 145 5 11 10 10 11 44 14 16 78 19 22 112 25 29 146 6 12 11 11 12 45 15 17 79 20 23 113 26 30 147 7 13 12 12 13 46 16 18 80 21 24 114 0 5 148 8 14 13 13 14 47 17 19 81 22 25 115 One 6 149 9 15 14 14 15 48 18 20 82 23 26 116 2 7 150 10 16 15 15 16 49 19 21 83 24 27 117 3 8 151 11 17 16 16 17 50 20 22 84 25 28 118 4 9 152 12 18 17 17 18 51 21 23 85 26 29 119 5 10 153 13 19 18 18 19 52 22 24 86 27 30 120 6 11 154 14 20 19 19 20 53 23 25 87 0 4 121 7 12 155 15 21 20 20 21 54 24 26 88 One 5 122 8 13 156 16 22 21 21 22 55 25 27 89 2 6 123 9 14 157 17 23 22 22 23 56 26 28 90 3 7 124 10 15 158 18 24 23 23 24 57 27 29 91 4 8 125 11 16 159 19 25 24 24 25 58 28 30 92 5 9 126 12 17 160 20 26 25 25 26 59 0 3 93 6 10 127 13 18 161 21 27 26 26 27 60 One 4 94 7 11 128 14 19 162 22 28 27 27 28 61 2 5 95 8 12 129 15 20 163 23 29 28 28 29 62 3 6 96 9 13 130 16 21 164 24 30 29 29 30 63 4 7 97 10 14 131 17 22 165 0 7 30 0 2 64 5 8 98 11 15 132 18 23 166 One 8 31 One 3 65 6 9 99 12 16 133 19 24 167 2 9 32 2 4 66 7 10 100 13 17 134 20 25 33 3 5 67 8 11 101 14 18 135 21 26

및

는 특정 m 시퀀스

의 다음과 같은 2개의 상이한 순환 이동 시퀀스로 볼 수 있다.Also, two sequences

And

Is a specific m sequence

Can be seen as two different cyclic shift sequences:

와 같이 규정될 수 있으며, x(i)는 초기값 x(0) = 0, x(1) = 0, x(2) = 0, x(3) = 0, x(4) = 1이란 조건 하에서 다음과 같이 주어진다.here,

X (i) is the initial value x (0) = 0, x (1) = 0, x (2) = 0, x (3) = 0, x (4) = 1 Is given by

는 m 시퀀스

의 순환 이동에 의해 다음과 같이 규정된다.In addition, the scrambling sequence in Equation 1

M sequence

The circular movement of is defined as follows.

는 초기 값 x(0) = 0, x(1) =0, x(2) = 0, x(3) =0, x(4) =1이란 조건 하에 다음과 같 이 주어질 수 있다.Where m0 is given by Table 5 above,

Can be given as follows under the condition that initial values x (0) = 0, x (1) = 0, x (2) = 0, x (3) = 0, and x (4) = 1.

및

는 간단하게 SSC0와 SSC1로 표기하기도 한다.Hereinafter, methods for transmitting four P-BCH boundary information using the S-SCH signal structure as described above will be described in detail as the first, second and other embodiments, respectively. Hereinafter, the two 31 length codes constituting the S-SCH

And

Is simply labeled SSC0 and SSC1.

1st Embodiment

First, we propose a method of representing four pieces of P-BCH boundary information as a QPSK modulation that modulates the entire S-SCH to one of +1, + j, -1, and -j.

3 is a view for explaining a method of representing four pieces of P-BCH boundary information using QPSK modulation of the S-SCH according to the first embodiment of the present invention.

In FIG. 3, four 10 ms frames are shown to represent each of four pieces of P-BCH information. The two S-SCHs present in each frame show that the positions in the frequency domain are swapped with each other.

First, the present embodiment proposes to display four pieces of P-BCH boundary information as a QPSK modulation that modulates the entire S-SCH to any one of +1, + j, -1, and -j. For example, 0 ms P-BCH boundary when modulated with +1, 10 ms P-BCH boundary when modulated with + j, 20 ms P-BCH boundary when modulated with -1, and modulated with -j It can be seen that it represents a 30ms P-BCH boundary. In this case, the S-SCH in the first frame of FIG. 3 is interpreted as representing the 0 ms P-BCH boundary since the entire S-SCH is modulated to +1 (ie, both SSC0 and SSC1 are modulated to +1). can do. In addition, since the S-SCH in the second frame of FIG. 3 is modulated with + j as a whole of the S-SCH (ie, both SSC0 and SSC1), the UE may interpret it as representing a 10 ms P-BCH boundary. In this manner, the four frames illustrated in FIG. 3 may represent four pieces of boundary information of the P-BCH.

2nd Embodiment

Next, the phase modulation of the S-SCH is performed as a modulation of the BPSK method in which the two codes SSC0 and SSC1 constituting the S-SCH are modulated to +1 or -1, and a combination of values modulated on these two codes is performed. We propose a method for indicating four pieces of P-BCH boundary information using the above method. That is, four P-BCH boundary information is four modulations of (+1. +1), (+1, -1), (-1, -1) and (-1, +1) for SSC0 and SSC1. Refers to the method corresponding to each value combination. Herein, it is assumed that the modulation value for SSC0 is expressed as x and y when the modulation value for SSC0 is y.

4 is a diagram for explaining a method for setting a combination of values modulated by BPSK in SSC0 and SSC1 to indicate four pieces of P-BCH boundary information according to the second embodiment of the present invention.

FIG. 4 also shows four 10 ms frames to represent each of four pieces of P-BCH information, similar to FIG. 3. In addition, the two S-SCHs present in each frame show that the positions in the frequency domain are swapped with each other.

For example, assume that four combinations of modulation values for SSC0 and SSC1 are mapped to four P-BCH boundary information as follows.

(+ 1. + 1)-> 0 ms P-BCH boundary

(+1, -1)-> 10 ms P-BCH boundary

(-1, -1)-> 20 ms P-BCH boundary

(-1, +1)-> 30 ms P-BCH boundary

In this case, since both SSC0 and SSC1 of the first frame of FIG. 4 are modulated to +1, the UE may interpret it as representing a 0 ms P-BCH boundary. In addition, since the second frame of FIG. 4 is modulated by SSC0 to +1 and SSC1 to -1, the UE can be interpreted as indicating a 10 ms P-BCH boundary. In this manner, the four frames illustrated in FIG. 4 may each represent four pieces of boundary information of the P-BCH.

Other embodiment

Meanwhile, in another embodiment of the present invention, as in the first embodiment described above, the QPSK scheme is used for modulation on the S-SCH, but the phase modulation of the S-SCH is performed as in the second embodiment described above. A method of representing 16 kinds of P-BCH boundary information using a combination of values modulated for two codes SSC0 and SSC1 constituting -SCH is proposed.

That is, modulation values +1, + j, -1, and -j for each of SSC0 and SSC1 may form the following 16 combinations, which are mapped to and used as information representing 16 P-BCH boundaries, respectively. Can be.

(+ 1. + 1)-> 0th P-BCH boundary

(+1, -1)-> 1st P-BCH boundary

(-1, -1)-> 2nd P-BCH boundary

(-1, +1)-> 3rd P-BCH boundary

(+ j. + j)-> 4th P-BCH boundary

(+ j, -j)-> 5th P-BCH boundary

(-j, -j)-> 6th P-BCH boundary

(-j, + j)-> 7th P-BCH boundary

(+ 1. + j)-> 8th P-BCH boundary

(+1, -j)-> 9th P-BCH boundary

(-1, -j)-> 10th P-BCH boundary

(-1, + j)-> 11th P-BCH boundary

(+ j. +1)-> 12th P-BCH boundary

(+ j, -1)-> 13th P-BCH boundary

(-j, -1)-> 14th P-BCH boundary

(-j, +1)-> 15th P-BCH boundary

In the present embodiment, the 1st to 15th P-BCH boundaries need not be limited to a specific time domain boundary value, and may be variously set according to the requirements of the system.

On the other hand, using the above-described principle, the present invention can be extended to represent M ² P-BCH boundary values using M-PSK modulation values corresponding to two codes SSC0 and SSC1 of the S-SCH.

For example, the following shows an example which shows 64 P-BCH information using 8-PSK.

(exp (j * 2 * pi * 0/8), exp (j * 2 * pi * 0/8))-> 0th P-BCH boundary

(exp (j * 2 * pi * 0/8), exp (j * 2 * pi * 1/8))-> 1st P-BCH boundary

(exp (j * 2 * pi * 0/8), exp (j * 2 * pi * 2/8))-> 2nd P-BCH boundary

(exp (j * 2 * pi * 0/8), exp (j * 2 * pi * 3/8))-> 3rd P-BCH boundary

.....

.....

(exp (j * 2 * pi * 5/8), exp (j * 2 * pi * 7/8))-> 60th P-BCH boundary

(exp (j * 2 * pi * 6/8), exp (j * 2 * pi * 6/8))-> 61st P-BCH boundary

(exp (j * 2 * pi * 6/8), exp (j * 2 * pi * 7/8))-> 62th P-BCH boundary

(exp (j * 2 * pi * 7/8), exp (j * 2 * pi * 7/8))-> 63rd P-BCH boundary

As described above with respect to the first, second and other embodiments, when the P-BCH boundary information is indicated for phase modulation of the S-SCH, the UE of the 3GPP LTE system may perform initial cell discovery (initial). The process of obtaining information from the cell search is as follows. First, timing synchronization and three cell ID information may be obtained using the P-SCH. Thereafter, the UE performs 168 cell group ID and 5 ms frame timing search using the signature information as shown in Table 5 using the S-SCH. Thereafter, the UE may acquire 40 ms P-BCH boundary information using the modulation value (or modulation value combination) modulated on the entire S-SCH or SSC0 / SSC1 as described above.

In addition, as described above, a method of signaling P-BCH boundary information and the UE obtaining the P-BCH boundary information using the method includes signaling a handover UE to obtain PRACH transmission information of the target cell and using the same. It may also be viewed as a method of obtaining PRACH transmission information.

Hereinafter, the present invention as described above will be described in an effective contrast with the following methods for obtaining PRACH transmission information. In particular, the following description is made in contrast to a method of extending an RS period and a method of using phase modulation of a synchronization channel according to the present invention. A single cell model representing an asynchronous network and a two cell model representing a synchronous network are considered. The process of acquiring P-BCH information by the UE is set to be performed in the same manner as described above.

When searching for a 40 ms P-BCH boundary with RS for 5 ms, the UE has 48 REs for the RS in the sync channel subframe and 60 in the 12 REs for the first OFDM symbol RS in the subsequent subframe. Assume using RS.

5 is a diagram illustrating the concept of a two-cell model for simulating the effects of the present invention.

In the two-cell model of the structure as shown in FIG. 5, it is assumed that different main sync codes (PSCs) are used by good cell planning. In the simulation environment, the connection cell 501 and the neighbor cell 502 are assumed as two synchronized cells. Also, the signal Iother from another cell is assumed to be AWGN. In other words, the signal Iconnected of the connection cell 501, the signal neighbor of the neighboring cell, and the AWGN signal Iother of the other cell are modeled as being synthesized by the synthesizer 503.

It is assumed that a replica-based correlation for timing acquisition is performed using a P-SCH and a 3-cell search is performed for a 5 ms interval. Thereafter, a ML (Maximal Likelihood) SSC search is performed for a 168 cell group ID search for a 5 ms interval, and a 5 ms frame boundary is searched. Specific simulation parameters are shown in Table 6 below.

Parameters Explanations Carrier frequency 2 GHz Sampling rate 1.92 MHz FFT size 128 CP type Short CP PSC 63-length ZC with root indices 25, 29, 34 SSC Circular shifts of 31-length M-sequence generated from x ^ 5 + x ^ 2 + 1 SSC mapping / index pairing Swapping / Diagonal pairing Number of hypotheses on S-SCH 336 (= 168 * 2) SSC scrambling PSC-based scrambling only generated from x ^ 5 + x ^ 3 + 1 Averaged duration of PSC 5 ms Averaged duration of SSC 5 ms Frequency offset  ± 1 ppm, ± 5 ppm (uniform distribution) Frequency offset estimator 0FF for ± 0.1 ppm ON (differential based) for ± 5 ppm PSC detection One-part replica based for ± 0.1ppm frequency offset SSC detection ML by coherent detection Channel estimation DFT-based estimation Tx power ratio between SCH and data 1 (same) RS boosting compared with SCH / data subcarriers 0 dB, 3 dB Cell specific RS shifting applied RS detection for 40ms P-BCH boundary Non-coherent detection # of Tx / Rx antennas 1 Tx and 2 Rx antennas Channel model TU6 UE speed 120 km / h Cell deployment scenario Single-cell / Two-cell scenario Ineighbor / Iother (for two-cell model) 3 dB Received timing difference 0

6 to 9 are graphs showing simulation results for explaining the effects of the embodiments of the present invention.

Specifically, FIG. 6 shows a case of a single cell model of TU 120 km / h having a frequency offset of 0.1 ppm, and FIG. 7 shows a detection error rate when the frequency offset is 5.0 ppm, which is the same as that of FIG. 6. In addition, FIG. 8 shows the case of the two-cell model of TU 120 km / h whose frequency offset is 0.1 ppm, and FIG. 9 is the same as FIG. 8, but shows the detection error rate when the frequency offset is 5.0 ppm.

6 to 9, "No modulation" indicates a detection error rate when no modulation is performed on the S-SCH. Although the UE cannot obtain P-BCH boundary information, it compares the performance. It is shown for. "QPSK modulation" is a case where P-BCH boundary information is represented by performing QPSK modulation on the entire S-SCH according to the first embodiment of the present invention, and "BPSK modulation" is SSC0 and SB0 according to the second embodiment of the present invention. This corresponds to the case of indicating P-BCH boundary information through a combination of BPSK modulated values in SSC1. In addition, "RS detection" represents a case of indicating P-BCH boundary information through RS period extension, and two cases of power boosting and power boosting of the RS.

6 to 9, the following conclusions can be obtained.

Overall, it can be seen that the second embodiment of the present invention using BPSK shows the best performance among the methods for indicating P-BCH boundary information.

In case of using RS, performance degradation is severe compared to other methods due to time / frequency selectivity and non-coherent search. This degradation is due to the high Doppler and frequency offset.

Also in the case of the first embodiment of the present invention using the QPSK method, good overall performance is obtained. However, in a high frequency offset situation (for example, FIG. 7 and FIG. 9), performance degradation when using the QPSK scheme can be observed.

In conclusion, as described above, it may be seen that using the BPSK modulation of the S-SCH is the most efficient among the solutions for the PRACH transmission timing problem, and provides a high flexibility to the UE. In addition, it can be seen that the aforementioned BPSK scheme does not cause any disadvantage in the current 3GPP LTE structure.

The detailed description of the preferred embodiments of the invention disclosed as described above is provided to enable any person skilled in the art to make and practice the invention. Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. I can understand that you can. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The P-BCH boundary information signaling method as described above and the P-BCH boundary information acquisition method of the UE using the same have been described in detail as an example of a 3GPP LTE system. However, it will be apparent to those skilled in the art that the present invention can be applied to the 3GPP LTE system as well as to any system capable of transmitting additional information using the phase modulation of the synchronization channel using the synchronization channel.

1 illustrates a physical layer random access preamble structure.

FIG. 2 is a diagram for explaining an example in which a UE decodes a longer length P-BCH to accumulate four P-BCH TTIs.

3 is a view for explaining a method of representing four pieces of P-BCH boundary information using QPSK modulation of the S-SCH according to the first embodiment of the present invention.

4 is a diagram for explaining a method for setting a combination of values modulated by BPSK in SSC0 and SSC1 to indicate four pieces of P-BCH boundary information according to the second embodiment of the present invention.

5 is a diagram illustrating the concept of a two-cell model for simulating the effects of the present invention.

6 to 9 are graphs showing simulation results for explaining the effects of the embodiments of the present invention.

Claims (11)

In the method for signaling physical broadcast channel (P-BCH) boundary information, Performing phase modulation on the synchronization channel; And Transmitting the phase modulated sync channel; Phase modulation of the synchronization channel has a modulation form corresponding to the number of boundary information of the P-BCH, Wherein each modulation type is predefined between a transmitting and receiving end so as to correspond to the boundary information of each P-BCH. The method of claim 1, The number of P-BCH boundary information is M ² , the synchronization channel is a sub-sync channel (S-SCH), The phase modulation of the S-SCH is performed as modulation according to any one of modulation values according to the M-PSK scheme for each of the two codes SSC0 and SSC1 constituting the S-SCH. Way. (Where M is an integer) The method of claim 2, The M ² P-BCH boundary information corresponds to a combination of M ² modulation values according to M modulation values for SSC0 and M modulation values for SSC1, respectively. The method of claim 1, The number of the P-BCH boundary information is four, and the synchronization channel is a sub-sync channel (S-SCH), physical broadcast channel boundary information signaling method. The method of claim 4, wherein The phase modulation of the S-SCH is performed as a QPSK type modulation for modulating the entire S-SCH to any one of +1, + j, -1, and -j. The method of claim 5, wherein The four P-BCH boundary information corresponds to each of four modulation values of +1, + j, -1, and -j for the S-SCH. The method of claim 4, wherein The phase modulation of the S-SCH is performed as modulation of the BPSK scheme for modulating the two codes SSC0 and SSC1 into +1 or -1 constituting the S-SCH. The method of claim 7, wherein The four P-BCH boundary information includes four kinds of (+1. +1), (+1, -1), (-1, -1), and (-1, +1) for the SSC0 and the SSC1. Physical broadcast channel boundary information signaling method corresponding to each combination of modulation values. (However, if the modulation value for SSC0 is x and the modulation value for SSC1 is y, (x, y) is indicated) In the method for acquiring physical broadcast channel (P-BCH) boundary information, Receiving a synchronization channel to perform timing acquisition and cell ID search; And Obtaining boundary information of the P-BCH through phase modulation information of the synchronization channel; Phase modulation of the synchronization channel has a modulation form corresponding to the number of boundary information of the P-BCH, Wherein each of the modulation types is predefined between the transmitting and receiving end to correspond to the boundary information of each of the P-BCHs. In the method for acquiring physical broadcast channel (P-BCH) boundary information, Searching for time synchronization and three cell IDs over a primary synchronization channel (P-SCH); Searching for 168 cell group IDs and 5 ms frame timing over an auxiliary synchronization channel (S-SCH); And Obtaining boundary information of the P-BCH through phase modulation information of the auxiliary synchronization channel; Phase modulation of the synchronization channel has a modulation form corresponding to the number of boundary information of the P-BCH, Wherein each of the modulation types is predefined between the transmitting and receiving end to correspond to the boundary information of each of the P-BCHs. A method for signaling handover user equipment (UE) to obtain resource area information for random access channel transmission, the method comprising: Performing phase modulation on the synchronization channel; And Transmitting the phase modulated sync channel; The phase modulation of the synchronization channel has a modulation form corresponding to the number of boundary information of a physical broadcast channel (P-BCH), Each of the modulation types is predefined between the transmitting and receiving end to correspond to the boundary information of each of the P-BCH, And the UE obtains the resource region information for the random access channel transmission through the P-BCH.

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