WO2015056991A1

WO2015056991A1 - Method and apparatus for controlling uplink random access procedure in mobile communication system

Info

Publication number: WO2015056991A1
Application number: PCT/KR2014/009732
Authority: WO
Inventors: 배정화; 최성호; 김민구
Original assignee: 삼성전자 주식회사
Priority date: 2013-10-18
Filing date: 2014-10-16
Publication date: 2015-04-23

Abstract

A signal transmitting/receiving method of a user equipment of a mobile communication system according to an embodiment of the present invention comprises the steps of: transmitting a first random access signal including a first random access preamble to a base station; receiving, from the base station, a first random access response signal including first timing advance (TA) information in response to the first random access signal; transmitting, to the base station, a second random access signal including a second random access preamble based on the state of the user equipment; receiving, from the base station, a second random access response signal including second TA information in response to the second random access signal, when the second random access signal is transmitted to the base station; and transmitting a signal to the base station according to third TA information determined on the basis of at least one of the first TA information and the second TA information. In a random access procedure for initial access to a network by the user equipment according to an embodiment of the present invention, the user equipment transmits, two or more times, an RACH preamble signal to a base station, so that a more accurate TA value can be predicted utilizing TA information from two or more response messages received.

Description

Method and apparatus for controlling uplink random access procedure in mobile communication system

The present invention relates to a mobile communication, and relates to a random access procedure for initial access to a network by one terminal in a communication system. More specifically, the present invention relates to a random access procedure method and control method for initial access of a network applied to an LTE or LTE-advanced system.

The random access process is divided into two types of contention based access procedure and non-contention based access procedure in LTE system. The contention-based random access method is used when the terminal initially accesses the LTE network and is connected to the network by competition with several terminals. The non-contention random access method is used for a function such as requesting a radio resource or an update is required because uplink time synchronization is not correct. In addition, in the non-contention random access method, the UE randomly selects a preamble ID and generates the RACH signal. The non-contention-based random access method generates the RACH by applying the preamble ID specified by the base station. There are two ways to distinguish. Accordingly, there is a need for a method and apparatus that can perform RACH more efficiently.

In order to solve the above problem, a method and apparatus according to an embodiment of the present disclosure is to provide an efficient RACH preamble transmission method and apparatus in a mobile communication system.

In order to achieve the above object, a signal transmission and reception method in a terminal of a mobile communication system according to an embodiment of the present disclosure is a base station to a first random access signal including a first random access preamble (random access preamble) Transmitting to; Receiving, from the base station, a first random access response signal including first timing advance (TA) information in response to the first random access signal; Transmitting a second random access signal including a second random access preamble to the base station based on the state of the terminal; When the second random access signal is transmitted to the base station, receiving a second random access response signal including second TA information from the base station in response to the second random access signal; And transmitting a signal to the base station according to the third TA information determined based on at least one of the first TA information and the second TA information.

According to another embodiment of the present disclosure, a signal transmission / reception method of a base station of a mobile communication system includes: receiving a first random access signal including a first random access preamble from a terminal; Transmitting a first random access response signal including first timing advance (TA) information to the terminal in response to the first random access signal; Receiving a second random access signal including a second random access preamble from the terminal based on the state of the terminal; When the second random access signal is received from the terminal, transmitting a second random access response signal including second TA information to the terminal in response to the second random access signal; And receiving a signal to which third TA information is applied based on at least one of the first TA information and the second TA information from the terminal.

Terminal of a mobile communication system according to another embodiment of the present disclosure includes a transceiver for transmitting and receiving a signal with a base station; And controlling the transceiver, transmitting a first random access signal including a first random access preamble to a base station, and corresponding to the first random access signal, a first timing advance ( receiving a first random access response signal including timing advance (TA) information from the base station and receiving a second random access signal including a second random access preamble based on a state of the terminal; And a second random access response signal including second TA information from the base station in response to the second random access signal when the second random access signal is transmitted to the base station. And a control unit for transmitting a signal to the base station according to the third TA information determined based on at least one of the 1 TA information and the second TA information. The.

A base station of a mobile communication system according to another embodiment of the present disclosure includes a transceiver for transmitting and receiving a signal with a terminal; And controlling the transceiver, receiving a first random access signal including a first random access preamble from a terminal, and corresponding to the first random access signal, a first timing advance ( transmitting a first random access response signal including timing advance (TA) information to the terminal, and transmitting a second random access signal including a second random access preamble based on a state of the terminal. And a second random access response signal including second TA information to the terminal in response to the second random access signal when the second random access signal is received from the terminal. And a controller configured to receive a signal from which the third TA information is applied based on at least one of the first TA information and the second TA information.

Random access procedure for the initial access to the network to the terminal according to an embodiment of the present disclosure is TA (Ta) from the two or more response messages received by the terminal transmits the RACH preamble signal to the base station one or more times RACH preamble signal more than once Timing Advanced) can be used to predict more accurate TA values.

1 is a diagram illustrating a conventional method for random access when a terminal initially accesses a network according to an embodiment.

2 is a diagram illustrating a method for initial network access of a terminal according to an embodiment.

3 is a diagram illustrating a method for initial network access of a terminal according to another exemplary embodiment.

4 is a diagram illustrating a method for initial network access of a terminal according to another exemplary embodiment.

5 is a diagram illustrating a method for initial network access of a terminal according to another exemplary embodiment.

6 is a diagram illustrating a positional relationship with time between a terminal and a base station according to an embodiment.

7 is a diagram illustrating message transmission timing between a base station and a terminal according to an embodiment.

8 is a diagram illustrating a method for initial network access of a terminal according to another exemplary embodiment.

9 is a diagram illustrating a method for initial network access of a terminal according to another exemplary embodiment.

10 is a view showing a network initial access method of a terminal according to another embodiment of the present disclosure.

11 is a view showing the components included in the terminal of an embodiment of the present disclosure.

12 is a diagram illustrating components included in a base station according to an embodiment of the present disclosure.

13 is a diagram illustrating an operation of a terminal according to an embodiment of the present disclosure.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents which are well known in the technical field to which the present invention belongs and are not directly related to the present invention will be omitted. This is to more clearly communicate without obscure the subject matter of the present invention by omitting unnecessary description.

For the same reason, in the accompanying drawings, some components are exaggerated, omitted or schematically illustrated. In addition, the size of each component does not fully reflect the actual size. The same or corresponding components in each drawing are given the same reference numerals.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the embodiments of the present invention make the disclosure of the present invention complete and the general knowledge in the technical field to which the present invention belongs. It is provided to fully convey the scope of the invention to those skilled in the art, and the invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

At this point, it will be understood that each block of the flowchart illustrations and combinations of flowchart illustrations may be performed by computer program instructions. Since these computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, those instructions executed through the processor of the computer or other programmable data processing equipment may be described in flow chart block (s). It creates a means to perform the functions. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block (s). Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-implemented process to create a computer or other programmable data. Instructions for performing the processing equipment may also provide steps for performing the functions described in the flowchart block (s).

In addition, each block may represent a portion of a module, segment, or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of order. For example, the two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the corresponding function.

In this case, the term '~ part' used in the present embodiment refers to software or a hardware component such as an FPGA or an ASIC, and '~ part' performs certain roles. However, '~' is not meant to be limited to software or hardware. '~ Portion' may be configured to be in an addressable storage medium or may be configured to play one or more processors. Thus, as an example, '~' means components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, and the like. Subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and the 'parts' may be combined into a smaller number of components and the 'parts' or further separated into additional components and the 'parts'. In addition, the components and '~' may be implemented to play one or more CPUs in the device or secure multimedia card.

An embodiment of the present disclosure relates to a random access procedure for initial access to a network by a terminal in an LTE communication system. The embodiment will be described based on the LTE communication system, but the main subject matter of the present specification is applicable to other communication systems having a similar technical background and channel form with a slight modification without departing from the scope of the present invention. This will be possible in the judgment of a person skilled in the art of the present invention.

In the embodiment, the initial access method is a method of transmitting the RACH preamble one or more times, receiving the transmitted preamble response, and processing the one or more TA information included in the received message in various ways to increase accuracy.

That is, when determining the transmission timing of any one of the message 3 of FIGS. 3 to 5 and 8 to 9, a method of applying the received two TA information on average, the method of applying the preceding TA, the later TA information It is proposed to determine the transmission timing through various methods such as applying the method. Although this value is received from the base station of the terminal corresponding to the timing information TA, the accuracy of the TA may be lowered due to the mobility of the terminal and the effect of the rapid channel, that is, the effects of fading and multipath. May include a method for solving

1 illustrates a conventional method for random access when a terminal initially accesses a network.

Referring to FIG. 1, in a method in which the terminal 102 performs a contention-based random access process with the base station 104, in step 105, the terminal 102 includes a message 1 including a random access preamble. It transmits to the base station 104 through. According to an embodiment, the preamble may be transmitted by the base station 104 by applying a randomly selected preamble ID to the terminal 102 to determine the type of the RACH signal that is message 1. In an embodiment, after transmitting the message 1, the terminal 102 may wait for a response of the base station 104 for a preset time. According to an embodiment, the time for waiting for the response may be referred to as a response reception window. The response reception window may be set in the terminal 102 or may be determined based on an upper signal received from the base station 104.

In an embodiment, if the terminal 102 does not receive a response from the base station 104 even after exceeding the response reception window time, the terminal 102 again transmits a signal including the message 1 previously. Power ramping may be used to transmit to base station 104. According to an embodiment, the operation of transmitting the signal including the message 1 to the base station 104 by increasing the transmission power may be selectively performed.

The base station 104 receiving the signal including the message 1 with the power value that succeeded in transmitting the message 1 through the process of step 105 in step 110 transmits a signal including the message 2 that is a response to the RACH signal in step 110 (102). In an embodiment, the message 2 may include one or more of UL resource allocation information (allocation RB size, frequency position), TA time synchronization, and power control information.

In step 115, the terminal 102 receiving the message 2 of the step 110 applies TA information based on the information included in the received message 2 to transmit a signal including the message 3 to the base station 104. You can update it. The step 115 may include a process of performing scrambling by applying a temporary terminal identifier (temporaty C RNTI) received by the terminal 102 in the message 2.

In step 120, the base station 104 may send a message 4 including the unique number C_RNTI of the terminal 102 and information indicating the end of the contention to the terminal 102 to terminate the initial random access process. . The operation based on FIG. 1 may be similarly applied in the following embodiment.

In the following description, random access procedures for initial access to a network are proposed to a terminal according to an embodiment.

Referring to FIG. 2, in a method in which a terminal performs a contention-based random access procedure with a base station, in step 205, the terminal 202 may transmit a signal including the message 1 to the base station 204. The message 1 may include a random access preamble.

In step 210, the base station 204 may transmit a signal including the message 2 that is a response to the received preamble to the terminal 202. The message 2 may include one or more of uplink (UL) resource allocation information and information on TA time synchronization.

In step 215, the terminal 202 may transmit the random access preamble sent in the message 1 to the base station 204 after receiving the preamble response received in step 210. According to an embodiment, the signal transmitted in step 215 may be transmitted at the same transmission power as the signal transmitted in step 205.

In step 220, the terminal 202 may receive a signal including the message 2 from the base station 204 in response to the message transmitted in step 215. The terminal 202 may obtain the information TA about time synchronization based on the message 2.

In operation 225, the terminal 202 may transmit a signal including the message 3 to the base station 204. Message 3 may be used for timing updates. In an embodiment, the terminal 202 may determine the transmission timing of the message 3 based on one or more of the TA information received in the previous step. TA information for transmitting the message 3 may be determined using one or more of the TA information received in step 210 and the TA information received in step 220.

In step 230, the base station 204 may transmit a signal including the message 4 indicating the end of the contention including the unique number C_RNTI of the terminal 202 to the terminal 202.

Referring to FIG. 3, the terminal 302 and the base station 304 may transmit and receive signals to each other.

In an embodiment, the operations of steps 305 to 320 may be performed corresponding to the operations of steps 205 to 220 of FIG. 2, respectively.

In step 325, the terminal 302 may determine the timing of transmitting the message 3 by averaging the TA information received in step 310 and the TA information received in step 320. More specifically, in an embodiment, the transmission timing for transmitting message 3 may be determined by averaging the TA0 value received in step 310 and the TA1 value received in step 320.

Step 330 may be performed to correspond to step 230 of FIG. 2.

According to such an embodiment, even when the reception time interval of the two messages 2 received in

steps

310 and 320, respectively, is short, the terminal 302 may increase accuracy in determining TA information.

Referring to FIG. 4, a signal may be transmitted and received between the terminal 402 and the base station 404.

In an embodiment, the operations of steps 405 to 420 may be performed corresponding to the operations of steps 205 to 220 of FIG. 2, respectively.

In step 425, the terminal 402 may determine TA information to be transmitted next by varying the weight a between the TA0 value received in step 410 and the TA1 value received in step 420. According to an embodiment, a method of determining a TA may be as follows. In an embodiment, a may have a value between 0 and 1. This method can be implemented by applying a value of 0.5 or more if it is determined that the TA is received more accurately.

New TA value = TA0 * (a-1) + TA1 * a

When a is 0.5, TA information can be obtained with the same result as in the embodiment of FIG.

FIG. 5 is a diagram illustrating a method for initial network access of a terminal according to another embodiment, FIG. 6 is a diagram illustrating a positional relationship with time between a terminal and a base station according to an embodiment, and FIG. 7 is a base station according to an embodiment. Is a diagram illustrating a message transmission timing between a terminal and a terminal.

5 to 7, the terminal 502 and the base station 504 may transmit and receive signals with each other.

In an embodiment, the operations of steps 505 to 520 may be performed corresponding to the operations of steps 205 to 220 of FIG. 2, respectively.

In an embodiment, the terminal 502 may store the TA information TA0 received in step 510 in a memory and apply the TA information as it is to transmit message 3 in step 525. In this method, the time for transmitting the second preamble receives the first message 2 and transmits it in the next subframe, and the second TA information can be ignored.

Step 530 may be performed to correspond to step 230 of FIG. 2.

In FIG. 6, the base station 602 may operate a cell 604 having a specific cell radius 606. In the present embodiment, the TA information may be applied to a terminal operating in an environment where the TA information does not change well. Therefore, the

TA information

622 and 624 of the message 2 received twice can be known as follows through the analysis on the terminal maximum speed v how fast the terminal can be affected. In the LTE system, one TA unit is 0.52us. Assuming that the terminal is located in A as shown in Figure 5 can be expressed as follows by the formula 'speed = distance / time'.

3x10 ⁸ (m / s) * Ts (s) = x (m)

Here, 3x10 ⁸ (m / s) means the speed of radio waves, and Ts (s) refers to the time when radio waves arrive from the base station 602 to the terminal 612. x (m) is the distance between the base station and the terminal position A. Assuming that such a terminal has moved from A to B due to the high speed v, it can be expressed as the following equation.

3x10 ⁸ (m / s) * (Ts + delta t) (s) = y (m)

In the above formula, delta t (s) is the time taken to move from position A to B at the speed of propagation. y (m) is the distance between the base station and the terminal location B.

Combine the above two formulas

3x10 ⁸ (m / s) * delta t (s) = yx (m)

In FIG. 7, the base station 702 may transmit and receive messages 1 705 and 715 and message 2 710 and 720 in correspondence with the terminal 704 and the second embodiment. In TA, the round trip must be taken into account, so delta t becomes 1TA / 2, which is 0.52 / 2us. Substituting this value and calculating, as a result, the moving distance of the terminal 612 becomes 78 (m). That is, the correlation between the terminal moving speed v and the interval T _TA (s) 725 receiving TA information is obtained as follows.

Travel speed v (m / s) * T _TA (s) = 78 (m)

For example, if the T _TA 725 is assumed to be 20 ms, it is 14040 km / h, and even if it is 100 ms, it becomes 2808 km / h. Therefore, even if TA0 of message 2 received in step 510 is applied, the TA value does not change well, so there is no effect on the system.

Referring to FIG. 8, the terminal 802 and the base station 804 may transmit and receive signals with each other.

In an embodiment, the operations of steps 805 to 820 may be performed corresponding to the operations of steps 205 to 220 of FIG. 2, respectively.

According to an embodiment, when the T _TA value, which is an interval for receiving TA information due to some cause, becomes large, a case in which the TA may change due to a sudden movement of the terminal 802 and a channel may occur. In this case, the final TA value can be derived as follows by additionally predicting the changed TA value.

T (s) = TA value received in the first message 2 (step 810) + predicted TA value

In the above equation, the predicted TA value may be determined based on the moving speed of the terminal 802 measured by the speed measuring unit included in the terminal 802. According to an embodiment, the speed measurer may include a Doppler predictor. In operation 825, the terminal 802 may apply a TA value determined based on the above equation to execute a timing update to the base station 804.

Step 830 may be performed to correspond to step 230 of FIG. 2.

Referring to FIG. 9, the terminal 902 and the base station 904 may transmit and receive signals with each other.

In an embodiment, the operations of steps 905 to 920 may be performed corresponding to the operations of steps 205 to 220 of FIG. 2, respectively.

In step 925, the terminal 902 may ignore the TA information received in step 910 and adjust the transmission timing of message 3 using only the TA information received in step 920. In the case of the embodiment, the TA0 information received first may be used when it is determined that time is not accurate.

When the terminal 902 transmits the second RACH preamble to the base station 904 (step 915), the transmission power of the signal for transmitting the second preamble may be basically determined to be the same as the access successful power in the first preamble. . However, if the time taken while receiving TA information of message 2, which is received twice in the above schemes, becomes longer, the transmission power may be changed. Therefore, the transmission power of the second preamble is estimated power as follows. In addition, the transmit power can be updated.

Transmit Power of Second Preamble = Transmit Power of First Preamble + Estimated Power Offset

The estimated power offset value can be estimated by comparing the RSRP values measured in the two messages 2.

Step 930 may be performed to correspond to step 230 of FIG. 2.

Referring to FIG. 10, the terminal 1002 and the base station 1004 may transmit and receive signals with each other.

In an embodiment, the operations of steps 1005 to 1020 may be performed corresponding to the operations of steps 205 to 220 of FIG. 2, respectively.

In step 1025, the terminal 1002 determines TA information based on one or more of TA0 received in step 1010, TA1 received in step 1020, and speed values of the terminal measured in steps 1005 to 1020, and transmits the TA information to the base station 1004. The timing update can be performed.

More specifically, if the speed of the terminal is long while the TA information is requested while the TA information is requested, the received TA value cannot be applied correctly. In the example, a value of a can be made small so that a more accurate TA value can be reflected. As a criterion for determining the speed, a value may be proportionally reduced as the speed increases based on the characteristic threshold value.

Step 1030 may be performed to correspond to step 230 of FIG. 2.

Referring to FIG. 11, the terminal 1102 of the embodiment may include a transceiver 1110 and a controller 1120. In addition, the controller 1120 may include one or more of the speed measuring unit 1122, the storage unit 1124, the RACH performing unit 1126, and the TA determining unit 1128. The components of the controller 1120 are exemplary and the operations of each of the components may be performed by separate or identical devices.

In an embodiment, the transceiver 1110 may transmit and receive a signal with a base station. The signal including the message 1 to the message 4 described in the embodiment can be transmitted and received with the base station.

The controller 1120 may control the operation of the entire terminal 1102 including the transceiver 1110.

The speed measuring unit 1122 may measure the moving speed of the terminal 1102. More specifically, the speed measuring unit 1122 may include a GPS module and a Doppler predictor.

The storage unit 1124 may store one or more of data included in a signal to be transmitted and received and a value required for the operation of the terminal 1102, and may include overall volatile and nonvolatile memories.

The RACH execution unit 1126 may select an preamble for the UE to perform the RACH and perform an operation of controlling a transmission power of a signal for transmitting the RACH.

The TA determiner 1128 may determine a TA value to be used by the terminal 1102 in the timing update based on one or more TA information received from the base station. The method of determining the TA value may be in accordance with the previously described embodiment.

Referring to FIG. 12, the base station 1104 of the embodiment may include a transceiver 1210 and a controller 1220. In addition, the controller 1220 may include one or more of a TA information generator 1222, a storage unit 1224, a resource allocator 1226, and an ID allocator 1228. The components of the controller 1220 are exemplary and the operations of each of the components may be performed by separate or identical devices.

In an embodiment, the transceiver 1210 may transmit and receive a signal with the terminal. The signal including the message 1 to the message 4 described in the embodiment can be transmitted and received with the terminal.

The controller 1120 may control the operation of the entire base station 1204 including the transceiver 1110.

The TA information generator 1222 may generate TA information based on the information received from the terminal.

The storage unit 1224 may store one or more of data included in a signal to be transmitted and received and a value required for the operation of the base station 1204, and may include overall volatile and nonvolatile memories.

The resource allocator 1226 may allocate radio resources for the UE to transmit and receive a signal with the base station 1204.

ID allocator 1228 The terminal may allocate an ID including the C-RNTI allocated through the RACH with the base station 1204 to the terminal.

Referring to FIG. 13, a terminal according to an embodiment may transmit a signal including a random access preamble to a base station (RACH).

In step 1310, the UE may lose a random access response (RAR) from the base station. The random access response may include one or more of TA information (TA0) and uplink radio resource information.

While performing

steps

1305 and 1310, the UE can measure its speed.

In step 1315, the terminal may determine whether the speed of the terminal exceeds a threshold value. In addition, according to an embodiment, it may be determined whether the speed of the terminal exceeds a threshold value for a predetermined time or more in a specific section. More specifically, it may be determined whether the speed of the terminal exceeds the threshold at least once while performing

steps

1305 and 1310. The threshold value may be determined based on information previously set in the terminal or received from the base station.

As a result of the determination, if the speed of the terminal does not exceed a threshold value, in step 1320, the terminal may update the transmission timing to the base station by applying TA information based on the received TA0. More specifically, if the speed of the terminal does not exceed the threshold value, the terminal may omit performing the additional RACH to the base station, and preferably may prevent or omit the additional RACH to be transmitted. .

As a result of the determination, when the speed of the terminal exceeds the threshold, in step 1325, the terminal may perform an additional RACH to the base station. In an embodiment, the terminal may perform the RACH in the same manner as in step 1305.

In step 1330, the terminal may receive a signal including TA information (TA1) and uplink radio resources from the base station.

While performing the

steps

1325 and 1330, the terminal can measure its speed.

In step 1335, the terminal determines a TA value based on one or more of the received TA0, TA1 and the speed of the terminal measured multiple times in each step, and updates the transmission timing to the reporter station based on the determined TA value. can do.

In step 230, the terminal may receive a signal including a message indicating the end of the contention including the unique number (C_RNTI) from the base station.

In a method of performing a contention-based random access procedure with a base station according to an embodiment, transmitting a random access preamble message 1, which is a message 1 signal, from a terminal, responding to a preamble received by the base station Transmitting message 2 together with UL resource allocation information and TA0 time synchronization information, transmitting a random access preamble sent to message 1 after the UE receives this preamble response, and then transmitting the preamble as it is. Resending the response message 2 with UL resource allocation information and TA 1 time synchronization information, and transmitting the message 3 to determine the transmission timing of the message 3 using the two TA information previously received. The transmitting step and the base station terminates the contention including the unique number (C_RNTI) of the terminal Li may comprise sending a message 4 to the UE.

In addition, in the method of performing a random access process according to another embodiment of the present disclosure, the time for transmitting message 3 is a new transmission timing (TA0 + TA1) / averaging two TA0 and TA1 included in the two messages 2 previously received. It may include a procedure for updating by applying 2. At this time, the applicable TA value = (TA0 + TA1) / 2 may be applied.

In addition, in the method of performing a random access process according to another embodiment of the present disclosure, the time for transmitting message 3 is a method of applying different weights a and 1-a to the TA0 value received first and the TA1 value received later. Can be applied as

TA value = TA0 x (a-1) + TA1 x a

In addition, in the method of performing a random access process according to an embodiment of the present disclosure, the transmission time may be updated by applying only the TA0 information received first without using the TA1 information received last.

In addition, in the method for performing a random access procedure according to an embodiment of the present disclosure, the time for transmitting the second preamble may receive message 2, which is a preamble response, and immediately transmit the message 2 to the next subframe.

In addition, in the method for performing a random access process according to an embodiment of the present disclosure, when the time (T _TA ) interval for receiving a _TA becomes large, when the message 3 is transmitted, the TA value is additionally predicted as follows. Can be derived together

T (s) = TA value received in the first message 2 + predicted TA value

In addition, in the method of performing a random access process according to an embodiment of the present disclosure, the predicted TA value may be estimated through the Doppler predictor and then additional TA value may be estimated.

In addition, in the method of performing a random access process according to an embodiment of the present disclosure, the time for transmitting message 3 may ignore TA0 information received first and use TA1 information received last.

In addition, in the method of performing a random access process according to an embodiment of the present disclosure, when the second preamble is sent, the transmit power may use the access success power in the first preamble.

In addition, in the method of performing a random access process according to an embodiment of the present disclosure, when the time for receiving TA information of the message 2 becomes long, the transmission power may be changed, so that the transmission power of the second preamble may be as follows. .

In addition, in the method of performing a random access process according to an embodiment of the present disclosure, the estimated power offset value may be estimated by comparing the RSRP values measured in the two messages 2.

On the other hand, the present specification and the drawings have been described with respect to the preferred embodiments of the present invention, although specific terms are used, it is merely used in a general sense to easily explain the technical details of the present invention and help the understanding of the invention, It is not intended to limit the scope of the invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims

In the method of transmitting and receiving signals in a terminal of a mobile communication system,

Transmitting a first random access signal including a first random access preamble to a base station;

Receiving, from the base station, a first random access response signal including first timing advance (TA) information in response to the first random access signal;

Transmitting a second random access signal including a second random access preamble to the base station based on the state of the terminal;

When the second random access signal is transmitted to the base station, receiving a second random access response signal including second TA information from the base station in response to the second random access signal; And

And transmitting a signal to the base station according to third TA information determined based on at least one of the first TA information and the second TA information.
The method of claim 1,

Transmitting the second random access signal to the base station;

The second random access signal is transmitted when there is a time interval in which the speed of the terminal is greater than or equal to a preset value in at least one of a time interval corresponding to the first random access signal transmission and a time interval corresponding to the reception of the first random response signal. Transmitting and receiving a signal comprising the step of transmitting to the base station.
The method of claim 1,

Transmitting the second random access signal to the base station;

When there is no time interval in which the speed of the terminal is greater than or equal to a preset value in at least one of a time interval corresponding to the first random access signal transmission and a time interval corresponding to the reception of the first random response signal, the second random access signal Omitting the transmission to the base station; further comprising,

And the third TA information is determined based on the first TA information.
The method of claim 1,

And the third TA information is determined based on a weight value determined based on the first TA information, the second TA information, and the moving speed of the terminal.
In the signal transmission and reception method of the base station of the mobile communication system,

Receiving a first random access signal including a first random access preamble from a terminal;

Transmitting a first random access response signal including first timing advance (TA) information to the terminal in response to the first random access signal;

Receiving a second random access signal including a second random access preamble from the terminal based on the state of the terminal;

When the second random access signal is received from the terminal, transmitting a second random access response signal including second TA information to the terminal in response to the second random access signal; And

And receiving a signal to which third TA information is applied based on at least one of the first TA information and the second TA information from the terminal.
The method of claim 5,

Receiving the second random access signal

If there is a time interval in which the speed of the terminal is greater than or equal to a preset value in a time interval corresponding to the first random access signal transmission and a time interval corresponding to the reception of the first random response signal, the terminal transmits the second interval from the terminal. Receiving a random access signal comprising the steps of transmitting and receiving a signal.
The method of claim 5,

If there is no time interval in which the terminal has a speed greater than or equal to a preset value in a time interval corresponding to the first random access signal transmission and a time interval corresponding to the reception of the first random response signal, the first TA information is provided. And receiving a signal from the terminal based on the third TA information determined based on the received signal.
The method of claim 6,

And the third TA information is determined based on a weight value to be applied to each TA value determined based on the first TA information, the second TA information, and the movement speed of the terminal.
In the terminal of the mobile communication system,

Transmitting and receiving unit for transmitting and receiving a signal with the base station; And

Controls the transceiver and transmits a first random access signal including a first random access preamble to a base station, and corresponding to the first random access signal, a first timing advance. Receives a first random access response signal including advance (TA) information from the base station, and transmits a second random access signal including a second random access preamble to the base station based on the state of the terminal And when the second random access signal is transmitted to the base station, in response to the second random access signal, receives a second random access response signal including second TA information from the base station, and receives the first random access response signal. And a control unit for transmitting a signal to the base station according to the third TA information determined based on at least one of the TA information and the second TA information. Is the terminal.
The method of claim 9,

The control unit

The second random access signal is transmitted when there is a time interval in which the speed of the terminal is greater than or equal to a preset value in at least one of a time interval corresponding to the first random access signal transmission and a time interval corresponding to the reception of the first random response signal. Terminal for transmitting to the base station.
The method of claim 9,

The control unit

When there is no time interval in which the speed of the terminal is greater than or equal to a preset value in at least one of a time interval corresponding to the first random access signal transmission and a time interval corresponding to the reception of the first random response signal, the second random access signal Omitting the transmission to the base station,

The third TA information is determined based on the first TA information.
The method of claim 9,

The third TA information is determined based on a weight value determined based on the first TA information, the second TA information, and the movement speed of the terminal.
In the base station of the mobile communication system,

Transmitting and receiving unit for transmitting and receiving a signal with the terminal; And

Controls the transceiver and receives a first random access signal including a first random access preamble from a terminal, and corresponding to the first random access signal, timing a first timing advance. transmitting a first random access response signal including advance (TA) information to the terminal, and transmitting a second random access signal including a second random access preamble from the terminal based on a state of the terminal. And when the second random access signal is received from the terminal, transmits a second random access response signal including second TA information to the terminal in response to the second random access signal. And a controller configured to receive a signal to which third TA information is applied based on at least one of the first TA information and the second TA information.
The method of claim 13,

The control unit

If there is a time interval in which the speed of the terminal is greater than or equal to a preset value in a time interval corresponding to the first random access signal transmission and a time interval corresponding to the reception of the first random response signal, the terminal transmits the second interval from the terminal. Receiving a random access signal.
The method of claim 13,

The control unit

If there is no time interval in which the terminal has a speed greater than or equal to a preset value in a time interval corresponding to the first random access signal transmission and a time interval corresponding to the reception of the first random response signal, the first TA information is provided. The base station, characterized in that for receiving a signal from the terminal based on the third TA information determined based on.
The method of claim 13,

The third TA information is determined based on a weight value to be applied to each TA value determined based on the first TA information, the second TA information, and the movement speed of the terminal.