integrated circuits

Abstract

To appropriately perform random access processing.SOLUTION: An integrated circuit is an integrated circuit that controls a transmitting device and includes a transmitting circuit that transmits a random access signal including a preamble portion and a data portion in Message A, and a control circuit that randomly selects one preamble number to be applied to the preamble portion from preamble numbers included in a group corresponding to the number of antenna ports applied to the data portion in Message A, some of the preamble numbers being included in Group A corresponding to a first number of antenna ports and other preamble numbers being included in Group B corresponding to a second number of antenna ports.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present disclosure relates to a transmission device, a reception device, a transmission method, and a reception method.

Background Art

[0002] In the standardization of 5G, a new radio access technology (NR: New Radio access technology) that is not necessarily backward compatible with LTE / LTE-Advanced is being discussed in 3GPP.

[0003] As a random access procedure in NR, in addition to the four-step random access (also called 4-step RACH (Random Access Channel)), the introduction of a two-step random access (also called 2-step RACH) is being considered (see, for example, Non-Patent Document 1 and Non-Patent Document 2).

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the random access method in NR has not been sufficiently studied.

[0006] Non-limiting embodiments of this disclosure contribute to providing a transmitter, receiver, transmission method, and reception method that can appropriately perform random access processing. [Means for solving the problem]

[0007] A transmitting device according to one embodiment of the present disclosure comprises a transmitting circuit that transmits a random access signal including at least a data section, and a control circuit that controls the configuration of the data section based on parameters relating to the transmission of the random access signal.

[0008] These comprehensive or specific embodiments may be implemented as systems, devices, methods, integrated circuits, computer programs, or recording media, or as any combination of systems, devices, methods, integrated circuits, computer programs, and recording media. [Effects of the Invention]

[0009] According to one embodiment of the present disclosure, random access processing can be performed appropriately.

[0010] Further advantages and effects of one embodiment of this disclosure will be made apparent from the specification and drawings. Such advantages and / or effects are provided by several embodiments and features described in the specification and drawings, but not all of them are necessarily provided in order to obtain one or more identical features. [Brief explanation of the drawing]

[0011] [Figure 1] A diagram illustrating an example of the CBRA's random access procedure. [Figure 2] A diagram illustrating an example of the CFRA random access procedure. [Figure 3] Block diagram showing a part of the configuration of the terminal according to Embodiment 1 [Figure 4] Block diagram showing a part of the configuration of the base station according to Embodiment 1 [Figure 5] Block diagram showing the configuration of the terminal according to Embodiment 1 [Figure 6] Block diagram showing the configuration of the base station according to Embodiment 1 [Figure 7] Sequence diagram showing an operation example of the terminal and the base station according to Embodiment 1 [Figure 8] Block diagram showing the configuration of the terminal according to Embodiment 2 [Figure 9] Block diagram showing the configuration of the base station according to Embodiment 2 [Figure 10] Sequence diagram showing an operation example of the terminal and the base station according to Embodiment 2 [Figure 11] Diagram showing an example of the RACH setting table according to Embodiment 2 [Figure 12] Diagram showing an example of the RACH setting table according to Embodiment 2 <* [Figure 13] Diagram showing an example of the RACH setting table according to Embodiment 2 [Figure 14] Diagram showing an example of the RACH setting table according to Embodiment 2 [Figure 15] Diagram showing an example of the RACH setting table according to Embodiment 2 [Figure 16] Block diagram showing the configuration of the terminal according to Embodiment 3 * [Figure 17] Block diagram showing the configuration of the base station according to Embodiment 3 [Figure 18] Sequence diagram showing an operation example of the terminal and the base station according to Embodiment 3 [Figure 19A] Diagram showing an example of the reference signal arrangement according to Embodiment 3 [Figure 19B] Diagram showing an example of the reference signal arrangement according to Embodiment 3 [Figure 20] Diagram showing an example of the DMRS arrangement pattern in PUSCH [Figure 21] Block diagram showing the configuration of the terminal according to Embodiment 4 [Figure 22] Block diagram showing the configuration of the base station according to Embodiment 4 [Figure 23] Sequence diagram showing an operation example of the terminal and the base station according to Embodiment 4 [Figure 24] A diagram showing an example of a RACH setting table according to Embodiment 4. [Figure 25] A diagram showing an example of a RACH setting table according to Embodiment 4. [Figure 26] A diagram showing an example of a RACH setting table according to Embodiment 4. [Figure 27] A diagram showing an example of a RACH setting table according to another embodiment. [Modes for carrying out the invention]

[0012] Embodiments of this disclosure will be described in detail below with reference to the drawings.

[0013] [Random Access Procedure] Random access procedures include, for example, two types of procedures (or types; hereinafter referred to as "RACH type"): CBRA (Contention Based Random Access) and CFRA (Contention Free Random Access).

[0014] [CBRA] Figure 1(a) shows an example of a 4-step random access CBRA (also called a 4-step CBRA).

[0015] As shown in Figure 1(a), the terminal (also called UE (User Equipment)) transmits a Preamble to the base station (e.g., called gNB) in the first stage transmission (MSG1). After receiving and decoding MSG1, the base station notifies the terminal in the second stage transmission (MSG2) of a response to the Preamble (e.g., also called an RA response) and scheduling information including the uplink transmission timing of MSG3. After receiving and decoding MSG2, the terminal uses the scheduling information instructed in MSG2 to notify the base station in the third stage transmission (MSG3) of information about the terminal (e.g., terminal ID, etc.) that will be used to establish a connection (also called an RRC (Radio Resource Control) connection). Finally, the base station notifies the terminal of a connection establishment response in the fourth stage transmission (MSG4).

[0016] Figure 1(b) shows an example of a two-step random access (CBRA) in CBRA.

[0017] As shown in Figure 1(b), in the first stage of transmission (for example, referred to as "msg A"), the terminal (UE) transmits a Preamble part (for example, corresponding to Preamble or MSG1 in Figure 1(a)) and a Data part (for example, corresponding to MSG3 in Figure 1(a)) to the base station (gNB). The terminal may transmit the Preamble part and Data part of msg A simultaneously, in a continuous period of time, or within a specified time (for example, within one slot).

[0018] Next, as shown in Figure 1(b), after receiving and decoding msg A, the base station notifies the terminal of the uplink transmission timing and connection establishment response (corresponding to MSG2 and MSG4 in Figure 1(a)) in the second stage transmission (hereinafter referred to as "msg B").

[0019] In NR, by introducing a two-stage random access as shown in Figure 1(b), it is expected that the latency of random access will be reduced in services for ultra-reliable and low-latency communications (e.g., URLLC).

[0020] Furthermore, in two-stage random access, the method by which a terminal transmits the Preamble part and Data part simultaneously, consecutively, or within a specified time frame as the transmission of msg A is also applicable to CFRA, which will be discussed later.

[0021] [CFRA] Figure 2(a) shows an example of CFRA.

[0022] As shown in Figure 2(a), the terminal is triggered to send the first stage Preamble (MSG1) by downlink control information (e.g., DCI: Downlink Control Information) from the base station. Based on the DCI from the base station, the terminal sends MSG1 to the base station. After receiving and decoding MSG1, the base station notifies the terminal of information such as the uplink transmission timing in the second stage transmission (MSG2).

[0023] Figure 2(b) shows an example of a two-step random access (CFRA) in CFRA.

[0024] As shown in Figure 2(b), when the terminal is triggered by DCI to send the first stage transmission (msg A) from the base station, it transmits the Preamble part and Data part to the base station simultaneously, continuously, or within a specified time (e.g., one slot) in the first stage transmission (msg A), similar to the case of CBRA (see, for example, Figure 1(b)). After receiving and decoding msg A, the base station notifies the terminal of the uplink transmission timing, etc., in the second stage transmission (msg B).

[0025] Furthermore, the introduction of the two-stage random access described above is not limited to the licensed bandwidth. For example, in NR, the operation of PRACH (Physical Random Access Channel) in the unlicensed bandwidth is also envisioned, similar to LAA (License Assisted Access). By introducing two-stage random access in the unlicensed bandwidth, for example, a reduction in LBT (Listen Before Talk) processing can be expected.

[0026] [PRACH] PRACH (for example, MSG1 in Figure 1(a) or Figure 2(a)) consists of a CP (Cyclic Prefix), a Preamble, and a GP (Guard Period). The Preamble is generated from a code sequence with good correlation characteristics (for example, a Cyclic-shifted Zadoff-Chu (CS-ZC) sequence). The CP is a signal that copies a part of the Preamble. The GP is a non-transmission period. Note that the Preamble is not limited to the CS-ZC sequence, but can be any code sequence with good correlation characteristics.

[0027] Information regarding these PRACHs is notified to the terminal, for example, as cell information from the base station. For example, a different CS-ZC sequence is uniquely associated with each Preamble number. In CBRA, for example, the terminal transmits a CS-ZC sequence corresponding to a randomly selected Preamble number from among several Preamble numbers (for example, called a "Preamble number group") as the Preamble. In CFRA, for example, the terminal transmits a CS-ZC sequence corresponding to a Preamble number instructed by DCI from the base station as the Preamble.

[0028] For example, even if multiple terminals transmit PRACH using the same time and frequency resources, if each terminal selects a different Preamble number, the base station can simultaneously detect multiple Preamble numbers (in other words, multiple terminal Preambles) by correlation detection of the CS-ZC sequence.

[0029] The time and frequency resources for PRACH are notified to the terminal, for example, using higher layer signaling (sometimes called RRC signaling or higher layer parameter). In some cases, multiple time and frequency resources may be notified to the terminal. In this case, CBRA allows the terminal to select the resources to use for PRACH from among the notified resources, based on specified conditions.

[0030] The above explains the random access procedure.

[0031] Incidentally, in NR, the details of the frame format of the Data part included in msg A in two-stage random access have not been sufficiently discussed. In particular, the configuration of the reference signal of the Data part of msg A (e.g., the Data Demodulation Reference Signal (DMRS)) and multi-layer transmission have not been sufficiently discussed.

[0032] Therefore, the following explains how to configure the Data part (in other words, the frame format) when a terminal sends PRACH in two-stage random access.

[0033] In the following explanation, "two-stage random access" refers to a random access procedure in which the Preamble part (equivalent to MSG1 in four-stage random access) and the Data part (equivalent to MSG3 in four-stage random access) are transmitted simultaneously, transmitted using consecutive wireless resources, or transmitted using wireless resources within a specified time (e.g., within a slot). In other words, two-stage random access refers to a random access procedure in which the Data part is transmitted together with the Preamble part. Alternatively, two-stage random access refers to a random access procedure in which the terminal transmits the Data part before receiving a response to the Preamble (equivalent to MSG2 in four-stage random access), or transmits the Data part without waiting for a response to the Preamble.

[0034] (Embodiment 1) To improve the reception quality in the Data part of msg A in two-stage random access, transmit diversity may be applied to the Data part, for example. Examples of transmit diversity include SFBC (Space Frequency Block Coding) or random precoding.

[0035] Furthermore, in order to transmit more information in the Data part, the terminal may transmit the Data part data using MIMO (Multiple Input Multiple Output) with multiple layers (Layer or Rank). In this case, for the base station to decode the Data part signal, a demodulation reference signal (DMRS) is required for each of the multiple antenna ports (also called Antenna ports). The DMRS for each antenna port must be transmitted using orthogonal resources, for example (e.g., frequency, time, and code resources).

[0036] In CBRA's two-stage random access, the base station cannot determine which terminal sent msg A unless it decodes the data part of msg A. Depending on the terminal's capabilities (e.g., UE capability), some terminals may only support one antenna. Therefore, with CBRA, the base station cannot instruct all terminals to transmit using multiple antenna ports.

[0037] On the other hand, in CFRA's two-stage random access, the base station notifies the terminal of the Preamble number to be used to transmit msg A when instructing the terminal to transmit msg A. Therefore, in the Preamble detection process, the base station can identify the terminal that transmitted msg A (e.g., PRACH) from the detected Preamble number. Thus, in CFRA, the base station can instruct each terminal to transmit using one or more antenna ports.

[0038] Therefore, in this embodiment, the number of ranks in the Data part (also called the rank value or number of layers) is set according to the type of random access procedure (RACH Type) such as CBRA and CFRA.

[0039] [Overview of the communication system] A communication system according to one embodiment of the present disclosure comprises a terminal 100 and a base station 200. In the following description, as an example, the terminal 100 (corresponding to a transmitting device) transmits PRACH, and the base station 200 (corresponding to a receiving device) receives PRACH.

[0040] Figure 3 is a block diagram showing a part of the configuration of a terminal 100 according to an embodiment of the present disclosure. In the terminal 100 shown in Figure 3, the wireless transmission unit 111 (corresponding to, for example, a transmission circuit) transmits a random access signal (e.g., PRACH) which includes at least a data part (e.g., a Data part). The rank determination unit 107 (corresponding to, for example, a control circuit) controls the configuration of the data part (e.g., the number of ranks) based on parameters related to the transmission of the random access signal (e.g., RACH type, etc.).

[0041] Figure 4 is a block diagram showing a part of the configuration of a base station 200 according to an embodiment of the present disclosure. In the base station 200 shown in Figure 4, the radio receiving unit 205 (corresponding to, for example, a receiving circuit) receives a random access signal (e.g., PRACH) which includes at least a data part (e.g., a Data part). The rank determination unit 208 controls the configuration of the data part (e.g., the number of ranks) based on parameters relating to the transmission of the random access signal.

[0042] [Device Configuration] Figure 5 is a block diagram showing the configuration of terminal 100 according to this embodiment.

[0043] In Figure 5, the terminal 100 includes an antenna 101, a wireless receiving unit 102, a demodulation / decoding unit 103, a RACH type determination unit 104, a Preamble generation unit 105, a Preamble resource allocation unit 106, a rank determination unit 107, a Data generation unit 108, a reference signal generation unit 109, a Data resource allocation unit 110, and a wireless transmission unit 111.

[0044] The wireless receiver 102 performs reception processing such as down-conversion and A / D conversion on the received signal received from the base station 200 via the antenna 101, and outputs the received signal obtained from the reception processing to the demodulation / decoding unit 103.

[0045] The received signals from the base station 200 may include, for example, signals in random access (e.g., msg B shown in Figure 1(b) or Figure 2(b)), higher layer signaling, or downlink control information (e.g., DCI).

[0046] The demodulation / decoding unit 103 demodulates and decodes the received signal input from the wireless receiver unit 102. The demodulation / decoding unit 103 outputs the decoded signal (for example, downlink control information) to the RACH type determination unit 104.

[0047] The RACH type determination unit 104 determines the type of random access procedure (RACH type) based on the downlink control information input from the demodulation / decoding unit 103.

[0048] For example, the RACH type determination unit 104 determines the RACH type to be "CFRA" when the transmission of random access (PRACH) is instructed by the downlink control information. For example, the RACH type determination unit 104 may determine the RACH type to be CFRA if, in the downlink control information, the CRC (Cyclic Redundancy Check) of DCI format1_0 in NR is scrambled using C-RNTI (Cell-Radio Network Temporary Identifier), and all "Frequency domain resource assignment" fields are 1.

[0049] Furthermore, for example, the RACH type determination unit 104 determines the RACH type to be "CBRA" if the transmission of random access is not instructed by the downlink control information. For example, the RACH type determination unit 104 may determine the RACH type to be CBRA when the terminal 100 initiates the transmission of PRACH (in other words, a random access signal) in a two-stage random access.

[0050] The RACH type determination unit 104 outputs RACH type information indicating the determined RACH Type (for example, either CBRA or CFRA) to the Preamble generation unit 105, the rank determination unit 107, and the Data generation unit 108.

[0051] If the RACH type indicated in the RACH type information input from the RACH type determination unit 104 is CBRA, the Preamble generation unit 105 randomly selects one Preamble number from the Preamble number group, for example. On the other hand, if the RACH type indicated in the RACH type information is CFRA, the Preamble generation unit 105 selects a Preamble number notified by the downlink control information, for example. The Preamble generation unit 105 generates a CS-ZC sequence using the sequence number and cyclic shift amount (CS amount) corresponding to the selected Preamble number, for example, and outputs the generated CS-ZC sequence as a Preamble part signal (or preamble signal) to the Preamble resource allocation unit 106. If the selected Preamble number is different, the Preamble generation unit 105 generates different code sequences (CS-ZC sequences, etc.) that are orthogonal or have small correlations.

[0052] The Preamble resource allocation unit 106 assigns the Preamble part signal input from the Preamble generation unit 105 to, for example, at least one of the frequency resources notified by upper-layer signaling. The Preamble resource allocation unit 106 also outputs the Preamble part signal to the wireless transmission unit 111 based on the set transmission timing.

[0053] The rank determination unit 107 determines the rank (or number of layers) of the Data part based on the RACH Type (e.g., CBRA or CFRA) indicated in the RACH type information input from the RACH type determination unit 104. The rank determination unit 107 outputs rank information indicating the determined rank to the Data generation unit 108 and the Data resource allocation unit 110. An example of the rank determination method used by the rank determination unit 107 will be described later.

[0054] The Data generation unit 108 generates a data signal (Data part signal) based on the RACH type information input from the RACH type determination unit 104 and the rank information input from the rank determination unit 107. For example, in the case of CBRA, the Data generation unit 108 generates a data signal that includes information used for connection establishment, such as the terminal ID (for example, equivalent to MSG3 in 4-stage random access). Also, in the case of CFRA, the Data generation unit 108 generates a data signal that includes a BFR (Beam Failure Report) or a Handover completion message. Furthermore, the Data generation unit 108 performs control such as transmission diversity or precoding based on the rank indicated in the rank information. Finally, the Data generation unit 108 encodes and modulates the generated data signal and outputs the modulated signal (data sequence) to the Data resource allocation unit 110.

[0055] The reference signal generation unit 109 generates, for example, a reference signal for data demodulation (e.g., DMRS), performs control such as precoding, and outputs the reference signal to the Data resource allocation unit 110. The reference signal may be generated from, for example, a PN series or a CS-ZC series. Note that, for example, if the Preamble can be used for channel estimation in the reception processing at the base station 200, the terminal 100 does not need to generate a reference signal.

[0056] The Data Resource Allocation Unit 110 allocates the Data part signals input from the Data Generation Unit 108 to frequency resources indicated by, for example, upper-layer signaling or downlink control information. The Data Resource Allocation Unit 110 also calculates the number of antenna ports based on the rank indicated in the rank information input from the rank determination unit 107. The Data Resource Allocation Unit 110 then allocates the reference signals input from the reference signal generation unit 109 to the time, frequency, or code resources corresponding to the calculated number of antenna ports. The Data Resource Allocation Unit 110 also outputs the Data part signals and reference signals to the wireless transmission unit 111 based on the set transmission timing.

[0057] The wireless transmission unit 111 performs transmission processing such as D / A conversion and upconversion on the Preamble part signal input from the Preamble resource allocation unit 106, and the Data part signal and reference signal input from the Data resource allocation unit 110. The wireless transmission unit 111 transmits the wireless signal obtained by the transmission processing (for example, corresponding to a two-stage random access PRACH (or msg A) (see Figure 1(b) or Figure 2(b))) from the antenna 101 to the base station 200.

[0058] [Base station configuration] Figure 6 is a block diagram showing the configuration of the base station 200 according to this embodiment.

[0059] In Figure 6, the base station 200 includes a control information generation unit 201, an encoding / modulation unit 202, a wireless transmission unit 203, an antenna 204, a wireless reception unit 205, a preamble detection unit 206, a RACH type determination unit 207, a rank determination unit 208, a channel estimation unit 209, and a data demodulation / decoding unit 210.

[0060] The control information generation unit 201 generates control information used by the terminal 100 for random access transmission, and outputs the generated control information to the encoding and modulation unit 202. The control information may include, for example, upper-layer signaling (e.g., RACH-Configuration in NR (RACH-ConfigCommon, RACH-ConfigDedicated, etc.)) and downlink control information for triggering CFRA (e.g., DCI format1_0 in NR).

[0061] Furthermore, the downlink control information may include, for example, the rank used for the Data part of msg A in two-stage random access, the number of antenna ports for the reference signal, the transmission diversity method, the precoding method, the preamble number in the Preamble part, or the allocated resources for the Preamble part.

[0062] Furthermore, not all control information needs to be notified to terminal 100 simultaneously. For example, some control information may be notified to terminal 100 as cell-common information, or as quasi-static notification information, or dynamic notification information (e.g., DCI). Also, some control information may be defined in the specifications as system-common information and may not need to be notified from base station 200 to terminal 100.

[0063] The encoding and modulation unit 202 modulates and encodes the control information input from the control information generation unit 201, and outputs the modulated signal to the wireless transmission unit 203.

[0064] The wireless transmission unit 203 performs transmission processing such as D / A conversion, upconversion, and amplification on the signal input from the encoding and modulation unit 202, and transmits the resulting wireless signal from the antenna 204 to the terminal 100.

[0065] The wireless receiver 205 performs reception processing such as down-conversion and A / D conversion on the PRACH signal (e.g., msg A in two-stage random access) received from the terminal 100 via the antenna 204, for example, using PRACH transmission resources available within the cell of the base station 200. The wireless receiver 205 outputs the signal obtained from the reception processing to the preamble detection unit 206, the channel estimation unit 209, and the data demodulation / decoding unit 210.

[0066] The Preamble detection unit 206 generates a replica signal for detecting the Preamble part signal using the sequence number and CS number corresponding to each Preamble number in the Preamble number group available within the cell of the base station 200. The Preamble detection unit 206 performs correlation processing between the generated replica signal and the signal input from the radio receiver unit 205 (e.g., msg A) to detect the PRACH preamble and estimate its timing. The Preamble detection unit 206 outputs the detected Preamble number to the RACH type determination unit 207 and the channel estimation unit 209, for example.

[0067] Furthermore, the correlation processing in the Preamble detection unit 206 may be a process that calculates a delay profile used in timing estimation by performing correlation processing in the time domain, or it may be a process that calculates a delay profile by performing correlation processing (division processing) in the frequency domain and then performing IFFT (Inverse Fast Fourier Transform).

[0068] The RACH type determination unit 207 determines the RACH type of the PRACH signal (random access signal) received from terminal 100 based on the Preamble number input from the Preamble detection unit 206.

[0069] For example, the RACH type determination unit 207 determines whether the detected Preamble number is the Preamble number for CFRA that was notified to terminal 100 by downlink control information. If the Preamble number is the Preamble number for CFRA, the RACH type determination unit 207 determines that the RACH type of the received PRACH signal is "CFRA". On the other hand, if the Preamble number is not the Preamble number for CFRA, the RACH type determination unit 207 determines that the RACH type of the received PRACH signal is "CBRA". The RACH type determination unit 207 outputs RACH type information indicating the determined RACH Type (for example, either CBRA or CFRA) to the rank determination unit 208.

[0070] The rank determination unit 208 determines the rank (or number of layers) of the data part based on the RACH type information (e.g., CBRA or CFRA) indicated in the RACH type information input from the RACH type determination unit 207. The rank determination unit 208 outputs rank information indicating the determined rank to the channel estimation unit 209 and the data demodulation / decoding unit 210. An example of the rank determination method in the rank determination unit 208 will be described later.

[0071] The channel estimation unit 209 calculates the number of antenna ports based on the rank indicated in the rank information input from the rank determination unit 208. The channel estimation unit 209 performs a frequency domain correlation process (e.g., division) using the replica reference signal for the reference signal assigned to the time, frequency, or code resource corresponding to each antenna port of the calculated number of antenna ports, and calculates the estimated channel value for each antenna port. The channel estimation unit 209 outputs the calculated estimated channel value to the data demodulation / decoding unit 210.

[0072] The Data demodulation / decoding unit 210 performs demodulation and decoding on the Data part signal included in the received signal input from the wireless receiver unit 205, based on the channel estimate value input from the channel estimation unit 209 and the rank indicated in the rank information input from the rank determination unit 208, and outputs the decoded data (for example, the Data part signal of msg A).

[0073] [Operation of terminal 100 and base station 200] An example of operation in a terminal 100 and base station 200 having the above configuration will be described.

[0074] Figure 7 is a sequence diagram showing an example of operation for terminal 100 (Figure 5) and base station 200 (Figure 6).

[0075] In Figure 7, the base station 200 notifies (in other words, broadcasts) cell information, which includes control information used by the terminal 100 for PRACH transmission (ST101). For example, the cell information may include higher-layer signaling, such as RACH-Configuration (RACH-ConfigCommon, RACH-ConfigDedicated, etc.) in NR.

[0076] If the base station 200 triggers a PRACH transmission from the terminal 100 (for example, in the case of CFRA), it transmits downlink control information (for example, DCI) to the terminal 100 (ST102). If the base station 200 does not trigger a PRACH transmission from the terminal 100 (for example, in the case of CBRA), it does not need to transmit the DCI.

[0077] Terminal 100 determines the RACH type (CBRA or CFRA) based, for example, on the presence or absence of downlink control information (DCI) (ST103). Terminal 100 also determines a rank based on the determined RACH type (ST104). In other words, terminal 100 determines the configuration of the Data part signal (e.g., the number of resources for the reference signal) based on the RACH type.

[0078] Terminal 100 generates a preamble part signal for msg A based on the RACH type (ST105), and generates a Data part signal for msg A (e.g., a data signal and a reference signal) based on the determined rank (ST106).

[0079] Terminal 100 transmits a PRACH signal (e.g., msg A) containing the generated Preamble part signal and Data part signal to base station 200 (ST107).

[0080] The base station 200 detects the Preamble part signal and identifies the Preamble number used in the PRACH signal (ST108). The base station 200 also determines the RACH type (e.g., CBRA or CFRA) based on the identified Preamble number (ST109), and determines the rank based on the determined RACH type (ST110).

[0081] Then, base station 200 performs channel estimation based on the determined rank and decodes the Data part signal using the channel estimation value (ST111).

[0082] [How ranks are determined] Next, an example of a method for determining rank in the rank determination unit 107 of terminal 100 and the rank determination unit 208 of base station 200 will be described.

[0083] Below, we will explain ranking determination methods 1-1 and 1-2 as examples.

[0084] <Decision method 1-1> In determination method 1-1, the terminal 100 and the base station 200 determine the maximum rank of the Data part of msg A according to the RACH Type (e.g., CBRA or CFRA) in the PRACH transmission.

[0085] For example, terminal 100 and base station 200 determine the maximum rank of the Data part of msg A to be "1" when the RACH type in PRACH transmission is CBRA.

[0086] On the other hand, terminal 100 and base station 200 determine the maximum rank of the Data part of msg A to be "X" (where X is a value of 1 or greater) when the RACH type in PRACH transmission is CFRA.

[0087] If the RACH type is CFRA, for example, terminal 100 determines the rank to use for transmitting the Data part of msg A from a value between 1 and X. For example, the rank value that terminal 100 uses for transmitting the Data part may be notified in the Downlink Control Information (DCI) to trigger CFRA. Alternatively, the rank value that terminal 100 uses for transmitting the Data part may be the rank value applied to the PUSCH transmission immediately preceding the PRACH transmission.

[0088] The maximum rank X may be notified from the base station 200 to the terminal 100 by quasi-static notification information such as upper-layer signaling, by dynamic control information such as DCI, or it may be defined by specifications, etc.

[0089] Thus, when the RACH type is CBRA, the rank of the Data part of msg A is fixed at 1. As mentioned above, with CBRA's two-stage random access, the base station 200 cannot determine which terminal 100 transmitted msg A unless it decodes the Data part of msg A, and therefore cannot instruct all terminals to transmit using multiple antenna ports. In contrast, by fixing the rank to 1 when the RACH type is CBRA, CBRA can be applied to all terminals 100, including terminals 100 that do not support transmission using multiple antenna ports.

[0090] Furthermore, when the RACH type is CFRA, the rank of the Data part of msg A is selected from 1 to X. As mentioned above, for example, in CFRA, the rank of the Data part used by terminal 100 is selected from 1 to X based on the rank applied to the downlink control information or the PUSCH transmission immediately preceding the PRACH transmission. This allows terminal 100 to dynamically change the rank of the Data part. For example, by dynamically changing the rank according to the reception quality, terminal 100 can appropriately set (e.g., increase or decrease) the amount of data transmitted in msg A in CFRA.

[0091] Furthermore, in determination method 1-1, the rank in the case of CBRA is fixed to 1, so compared to a method in which, for example, both the ranks of CBRA and CFRA are instructed from the base station 200 to the terminal 100, the amount of signaling control information required to instruct the rank of CBRA can be reduced.

[0092] Alternatively, in CFRA, a trigger type may be assigned to the type (or amount) of data to be transmitted to terminal 100, and a rank may be uniquely determined according to the trigger type.

[0093] <Decision method 1-2> In determination method 1-2, the maximum rank in the Data part of msg A is fixed, regardless of the PRACH Type.

[0094] For example, terminal 100 and base station 200 determine the maximum rank of the Data part of msg A to "1" regardless of whether the RACH Type in PRACH transmission is CBRA or CFRA. In other words, regardless of whether the RACH type is CBRA or CFRA, the rank of the Data part of msg A is fixed at 1. In this case, the amount of signaling required to instruct terminal 100 from base station 200 regarding the rank of the Data part of msg A can be reduced. Also, since the rank of the PRACH signal is fixed, the control of PRACH transmission can be simplified.

[0095] The method for determining rank according to this embodiment has been described above.

[0096] Thus, in this embodiment, the terminal 100 and the base station 200 control the configuration of the Data part signal based on the RACH type, which is one of the parameters related to the transmission of the PRACH signal. For example, the terminal 100 and the base station 200 determine the number of resources (e.g., rank or number of antenna ports) of the reference signal (DMRS) for demodulating the data signal in the Data part based on the RACH type.

[0097] This allows for appropriate control of the configuration of the reference signal (e.g., DMRS) of the Data part included in msg A and multi-layer transmission in, for example, two-stage random access of NR. Therefore, terminal 100 can efficiently transmit the PRACH signal for two-stage random access according to the RACH type.

[0098] In this embodiment, a method for determining the "maximum rank" based on RACH type was described as an example. However, in the rank determination method according to this embodiment, instead of the maximum rank, the maximum number of antenna ports, in other words, the number of resources of reference signals orthogonal by time, frequency, or code, may be determined. The number of antenna ports must be at least equal to the number of ranks. Therefore, the method for determining the maximum number of antenna ports is defined in the same way as when determining the maximum rank.

[0099] Furthermore, even with a rank of 1, multiple antenna ports may be configured. For example, this may occur when applying transmit diversity (e.g., SFBC) to the data part.

[0100] (Embodiment 2) Embodiment 1 described a method for determining the rank of the Data part of msg A according to the RACH type. In contrast, this embodiment describes a method for determining the rank of the Data part of msg A according to the "preamble number" or "preamble time and frequency resources" of the preamble part.

[0101] [Device Configuration] Figure 8 is a block diagram showing the configuration of the terminal 300 according to this embodiment. In Figure 8, components similar to those in Embodiment 1 (Figure 5) are denoted by the same reference numerals, and their descriptions are omitted.

[0102] In terminal 300, the RACH configuration table 301 is a table in which Preamble numbers are grouped according to the rank value used in the Data part of msg A. The information contained in the RACH configuration table 301 may be notified from base station 400 to terminal 300 by, for example, quasi-static notification information (e.g., upper-layer signaling) or dynamic notification information (e.g., DCI). Alternatively, the information contained in the RACH configuration table 301 may be specified in the specifications as system common information and may not be notified from base station 400 to terminal 300.

[0103] The information contained in the RACH setting table 301 is output to, for example, the Preamble number selection unit 302 and the rank determination unit 304, respectively. An example of the RACH setting table 301 will be described later.

[0104] The Preamble number selection unit 302 selects the Preamble number to be used for PRACH transmission. The Preamble number selection unit 302 outputs Preamble information indicating the selected Preamble number to the Preamble generation unit 303 and the rank determination unit 304.

[0105] For example, if the RACH type is CBRA, the Preamble number selection unit 302 refers to the RACH setting table 301 and randomly selects one Preamble number from among the Preamble numbers included in the group (Preamble number group) associated with the information of the terminal 300. The information of the terminal 300 may be at least one of the following: for example, the rank of the Data part, the path loss between the terminal 300 and the base station 400, and the amount of information in the Data part (e.g., the number of bits), or it may be other information (e.g., information about msg A or the Data part).

[0106] On the other hand, if the RACH type is CFRA, the Preamble number selection unit 302 selects the Preamble number notified by the downlink control information input from the demodulation / decoding unit 103.

[0107] An example of how to select a Preamble number in the Preamble number selection unit 302 will be described later.

[0108] The Preamble generation unit 303 generates a CS-ZC sequence using the sequence number and CS amount corresponding to the Preamble number indicated in the Preamble information input from the Preamble number selection unit 302, and outputs a signal that has undergone processing such as precoding to the generated CS-ZC sequence as a Preamble part signal to the Preamble resource allocation unit 106.

[0109] The rank determination unit 304 refers to the RACH setting table 301 and determines (in other words, judges) the rank corresponding to the Preamble number indicated in the Preamble information input from the Preamble number selection unit 302. It then outputs rank information indicating the determined rank to the Data generation unit 108 and the Data resource allocation unit 110. An example of the rank determination method used by the rank determination unit 304 will be described later.

[0110] [Base station configuration] Figure 9 is a block diagram showing the configuration of the base station 400 according to this embodiment. In Figure 9, components similar to those in Embodiment 1 (Figure 6) are denoted by the same reference numerals, and their descriptions are omitted.

[0111] In base station 400, the RACH setting table 401 is a table in which Preamble numbers are grouped according to the rank (rank value) used in the Data part of msg A, similar to the RACH setting table 301 held by terminal 300. The information contained in the RACH setting table 401 is output to, for example, the rank determination unit 402. An example of the RACH setting table 401 will be described later.

[0112] The rank determination unit 402, like the rank determination unit 304 of terminal 300, refers to the RACH setting table 401 to determine (in other words, judge) the rank corresponding to the Preamble number input from the Preamble detection unit 206. The rank determination unit 402 outputs rank information indicating the determined rank to the channel estimation unit 209 and the data demodulation / decoding unit 210. An example of the rank determination method in the rank determination unit 402 will be described later.

[0113] [Operation of terminal 300 and base station 400] An example of operation in a terminal 300 and base station 400 having the above configuration will be described.

[0114] Figure 10 is a sequence diagram showing an example of operation of terminal 300 (Figure 8) and base station 400 (Figure 9). In Figure 10, the same reference numerals are used for operations that are the same as in Embodiment 1 (see, for example, Figure 7), and their descriptions are omitted.

[0115] In Figure 10, terminal 300, for example, refers to the RACH configuration table 301 and randomly selects one Preamble number from a group of Preamble numbers corresponding to information about terminal 300 (an example of which will be described later) (ST201). Terminal 300 also refers to the RACH configuration table 301 and selects a rank corresponding to the selected Preamble number (ST202).

[0116] Meanwhile, base station 400 refers to RACH configuration table 401 to determine the rank corresponding to the Preamble number used in the PRACH signal (in other words, the detected Preamble number) (ST203).

[0117] [How ranks are determined] Next, we will explain an example of a method for determining the rank in terminal 300 and base station 400.

[0118] Below, we will explain ranking determination methods 2-1, 2-2, and 2-3 as examples.

[0119] <Decision method 2-1> The RACH setting tables 301 and 401 related to determination method 2-1 are, for example, tables that associate the Preamble number of the Preamble part of msg A with the rank to be applied to the Data part of msg A, as shown in Figure 11.

[0120] The Preamble number selection unit 302 of terminal 300 selects the rank of the Data part of msg A using, for example, in the case of CBRA, at least one of the following pieces of information about terminal 300. (1) Reception quality (e.g., path loss) (2) The amount of data in the Data part of msg A (e.g., number of bits) (3) UE Capability (e.g., number of transmitting antennas) (4) Rank applied to the PUSCH transmission immediately preceding the PRACH transmission

[0121] The Preamble number selection unit 302 then, for example, refers to the RACH setting table 301 shown in Figure 11 and randomly selects one Preamble number from among the Preamble numbers included in the group corresponding to the selected rank.

[0122] For example, if the selected rank is 1, the Preamble number selection unit 302 selects one Preamble number from Preamble numbers 0 to 2 included in group A shown in Figure 11. Similarly, if the selected rank is 2, the Preamble number selection unit 302 selects one Preamble number from Preamble numbers 3 and 4 included in group B shown in Figure 11.

[0123] Furthermore, the Preamble number selection unit 302 selects, for example, in the case of CFRA, a Preamble number included in the DCI notified by the base station 400.

[0124] The rank determination unit 304 of terminal 300 refers to the RACH setting table 301 and determines (or judges) the rank of the Data part corresponding to the Preamble number selected in the Preamble number selection unit 302. For example, in Figure 11, if Preamble number 3 is selected in the Preamble number selection unit 302, the rank determination unit 304 determines the rank of the Data part of msg A to be 2. The same applies if the Preamble number selected in the Preamble number selection unit 302 is any other number.

[0125] In the determination method 2-1, the rank of the Data part is selected when the Preamble number is selected in the Preamble number selection unit 302, so the rank determination unit 304 may use the rank selected in the Preamble number selection unit 302 as is.

[0126] Furthermore, the rank determination unit 402 of the base station 400 refers to the RACH setting table 401 to determine (or judge) the rank of the Data part corresponding to the Preamble number detected by the Preamble detection unit 206. For example, in Figure 11, if Preamble number 3 is detected by the Preamble detection unit 206, the rank determination unit 402 determines the rank of the Data part of msg A to be 2. The same applies if the Preamble number detected by the Preamble detection unit 206 is any other number.

[0127] Thus, in determination method 2-1, the Preamble number of the Preamble part of msg A is associated with the rank to be applied to the Data part of msg A. As a result, terminal 300 can determine the rank according to the Preamble number, eliminating the need for control information to notify terminal 300 of the rank from base station 400, and thus reducing the amount of signaling.

[0128] Furthermore, in determination method 2-1, the base station 400 can recognize the rank of the Data part of msg A selected by the terminal 300 when detecting the Preamble. In other words, the base station 400 can recognize the rank of the Data part before decoding the Data part of msg A. Therefore, in determination method 2-1, a rank of 1 or higher can be applied to the Data part of msg A in addition to CFRA, as well as CBRA, thereby increasing the amount of information that can be transmitted in the Data part of msg A.

[0129] Note that the table shown in Figure 11 is just one example and is not limited to the association between Preamble numbers and ranks shown in Figure 11.

[0130] <Decision method 2-2> The RACH setting tables 301 and 401 related to determination method 2-2 are, for example, tables that associate the Preamble number of the Preamble part of msg A, the rank applied to the Data part of msg A, and the path loss value measured from the downlink channel, as shown in Figure 12.

[0131] Path loss measured from the downlink channel may be measured using, for example, a synchronization signal.

[0132] As shown in Figure 12, groups with greater path loss are assigned lower ranks.

[0133] Furthermore, the criteria for determining path loss (a criterion for determining whether path loss is large or small, such as a threshold) may be defined in the specifications, for example, or notified by quasi-static notification information such as upper-layer signaling, or by dynamic notification information such as DCI.

[0134] The Preamble number selection unit 302, for example in the case of CBRA, refers to the RACH setting table 301 shown in Figure 12 and randomly selects one Preamble number from among the Preamble numbers included in the group corresponding to the path loss value measured from the downlink channel. For example, if the path loss is "large", the Preamble number selection unit 302 selects one Preamble number from Preamble numbers 0 to 2 included in group A shown in Figure 12. Similarly, for example, if the path loss is "small", the Preamble number selection unit 302 selects one Preamble number from Preamble numbers 3 and 4 included in group B shown in Figure 12.

[0135] Furthermore, the Preamble number selection unit 302 selects, for example, in the case of CFRA, a Preamble number included in the DCI notified by the base station 400.

[0136] Note that the operation of the rank determination unit 304 of terminal 300 and the rank determination unit 402 of base station 400 is the same as in determination method 2-1, so the explanation is omitted.

[0137] Thus, in determination method 2-2, the Preamble number of the Preamble part of msg A, the rank to be applied to the Data part of msg A, and the path loss are associated. As a result, terminal 300 can determine the rank according to the path loss, eliminating the need for control information to notify terminal 300 of the rank from base station 400, and thus reducing the amount of signaling.

[0138] Furthermore, in determination method 2-2, terminal 300 can easily select a rank according to the path loss, thus simplifying the implementation of terminal 300.

[0139] Furthermore, in determination method 2-2, similar to determination method 2-1, the base station 400 can recognize the rank of the Data part of msg A selected at terminal 300 when detecting the Preamble. Therefore, in CBRA as well, a rank of 1 or higher can be applied to the Data part of msg A, increasing the amount of information that can be transmitted in the Data part of msg A.

[0140] Method 2-2 described the case where path loss and rank are related. However, the parameter associated with rank is not limited to path loss; for example, any parameter that has a high relationship with rank (for example, a parameter related to reception quality) is acceptable.

[0141] Furthermore, the table shown in Figure 12 is just an example, and is not limited to the association between Preamble number, rank, and path loss shown in Figure 12. For example, Figure 12 shows the case of two levels of path loss (large or small), but there may be three or more levels of path loss. In other words, there may be three or more groups corresponding to path loss.

[0142] <Decision method 2-3> The RACH setting tables 301 and 401 related to determination method 2-3 are, for example, tables that associate the Preamble number of the Preamble part of msg A, the rank applied to the Data part of msg A, and the amount of information (e.g., number of bits) of the Data part of msg A, as shown in Figure 13.

[0143] As shown in Figure 13, groups with a larger amount of information in the Data part are assigned a higher rank.

[0144] Furthermore, the criteria for determining the amount of information (amount of information: a criterion for determining whether it is large or small, for example, a threshold) may be defined in the specifications, for example, and may be notified by quasi-static notification information such as upper-layer signaling, or by dynamic notification information such as DCI.

[0145] The Preamble number selection unit 302, for example in the case of CBRA, refers to the RACH setting table 301 shown in Figure 13 and randomly selects one Preamble number from among the Preamble numbers included in the group corresponding to the amount of information in the Data part of msg A. For example, if the amount of information is "small", the Preamble number selection unit 302 selects one Preamble number from Preamble numbers 0 to 2 included in group A shown in Figure 13. Similarly, if the amount of information is "large", the Preamble number selection unit 302 selects one Preamble number from Preamble numbers 3 and 4 included in group B shown in Figure 13.

[0146] Furthermore, the Preamble number selection unit 302 selects, for example, in the case of CFRA, a Preamble number included in the DCI notified by the base station 400.

[0147] Note that the operation of the rank determination unit 304 of terminal 300 and the rank determination unit 402 of base station 400 is the same as in determination method 2-1, so the explanation is omitted.

[0148] Thus, in determination method 2-3, the Preamble number of the Preamble part of msg A, the rank to be applied to the Data part of msg A, and the amount of information in the Data part of msg A are associated. As a result, terminal 300 can determine the rank according to the amount of information in the Data part, eliminating the need for control information to notify terminal 300 of the rank from base station 400, and thus reducing the amount of signaling.

[0149] Furthermore, in determination method 2-3, terminal 300 can send the Data part using a higher rank when the amount of information in the Data part of msg A is large, for example, thus reducing the number of symbols in the Data part of msg A.

[0150] Furthermore, in determination method 2-3, similar to determination method 2-1, the base station 400 can recognize the rank of the Data part of msg A selected at terminal 300 when detecting the Preamble. Therefore, CBRA can also apply a rank of 1 or higher to the Data part of msg A, thereby increasing the amount of information that can be transmitted in the Data part of msg A.

[0151] Furthermore, the table shown in Figure 13 is just an example, and is not limited to the association between Preamble number, rank, and information quantity shown in Figure 13. For example, Figure 13 shows the case of two types of information quantity (large or small), but there may be three or more types of information quantity. In other words, there may be three or more groups corresponding to the information quantity.

[0152] The method for determining rank according to this embodiment has been described above.

[0153] Thus, in this embodiment, the terminal 300 and the base station 400 control the configuration of the Data part signal based on the Preamble number, which is one of the parameters related to the transmission of the PRACH signal. For example, the terminal 100 and the base station 200 determine the number of resources (e.g., rank or number of antenna ports) of the reference signal (DMRS) for demodulating the data signal in the Data part based on the Preamble number.

[0154] This allows for appropriate control of the configuration of the reference signal (e.g., DMRS) of the Data part included in msg A and multi-layer transmission in, for example, two-stage random access of NR. Therefore, for example, terminal 300 can efficiently transmit the PRACH signal for two-stage random access according to the Preamble number.

[0155] (Variation 1 of Embodiment 2) In this embodiment, as shown in Figure 14, the Preamble number of the Preamble part of msg A, the rank to be applied to the Data part of msg A, and the combination of the amount of information and path loss in the Data part of msg A may be associated. In Figure 14, as an example, the Rank 2 group is associated with the case where the amount of information is "large" and the path loss is "small," and the Rank 1 group is associated with cases different from the above case. By using the RACH setting tables 301 and 401 shown in Figure 14, the terminal 300 and the base station 400 can select a rank according to the amount of information and path loss in the Data part of msg A.

[0156] (Variation 2 of Embodiment 2) In this embodiment, as an example, the case in which RACH setting tables 301 and 401 include values ​​up to rank 2 (for example, Figures 11, 12, 13, and 14) has been described. However, RACH setting tables 301 and 401 may also include ranks higher than rank 2. For example, in the RACH setting tables 301 and 401 shown in Figure 15, three groups associated with ranks 1, 2, and 4 are set.

[0157] (Variation 3 of Embodiment 2) In this embodiment, RACH setting tables 301 and 401 were described, which associate the Preamble number of the Preamble part of msg A with the rank applied to the Data part of msg A. However, RACH setting tables 301 and 401 may include the number of antenna ports instead of the rank applied to the Data part of msg A.

[0158] (Variation 4 of Embodiment 2) In CFRA, terminal 300 may override the rank based on the rank notified by the Downlink Control Information (DCI), rather than applying the association between the Preamble number defined in RACH setting tables 301 and 401 and the rank in the Data part of msg A. Applying the rank notified by DCI allows for more flexible rank control. For example, if there is only one Preamble number corresponding to rank 2 in RACH setting tables 301 and 401, it is not possible to assign rank 2 to multiple terminals. In contrast, terminal 300 can increase the number of terminals that can use rank 2 in CFRA by prioritizing the application of the rank notified by DCI.

[0159] (Variation 5 of Embodiment 2) In this embodiment, RACH setting tables 301 and 401 were described, which associate the Preamble number of the Preamble part of msg A with the rank applied to the Data part of msg A. However, in RACH setting tables 301 and 401, instead of the Preamble number, at least one of the PRACH time resource and frequency resource may be associated with the rank applied to the Data part.

[0160] In other words, terminal 100 and base station 200 should determine the number of DMRS resources in the Data part (e.g., rank or number of antenna ports) based on the resources used to transmit the PRACH signal (e.g., the Preamble number or PRACH resource mentioned above).

[0161] For example, in NR, the number of PRACH frequency resources is instructed to terminal 300 by control information called "prach-FDM," which is a higher-layer signaling method, and can be selected from 1, 2, 4, or 8. Furthermore, the resources used to transmit PRACH are associated with the SSB (Synchronization Signal Block) index, which is the index of the downlink synchronization signal.

[0162] Furthermore, depending on the settings for upper-layer signaling, a single SSB index may be associated with multiple PRACH resources (also called RACH Occasions). In this case, terminal 300 randomly selects one resource from among the multiple PRACH resources.

[0163] For example, if there are four PRACH resources (e.g., #0, 1, 2, 3) and each resource is associated with a rank (e.g., 1, 1, 1, 2), the terminal 300 may select a PRACH resource and send msg A according to the rank it has selected. For example, in the above example, if the terminal 300 selects rank 1, it will randomly select one resource from PRACH resources #0, 1, and 2 and send msg A.

[0164] Thus, similar to the Preamble number, the same effect as in this embodiment can be achieved by associating the rank applied to the PRACH time and frequency resources and the Data part.

[0165] (Embodiment 3) Embodiments 1 and 2 described a method for controlling the rank of the Data part of msg A. In contrast, this embodiment describes a method for controlling the resources (e.g., number of symbols or symbol position) of the reference signal (e.g., DMRS) of msg A.

[0166] When a base station demodulates and decodes the Data part of msg A, it performs channel estimation. Possible methods for channel estimation include using a reference signal placed in the Data part of msg A, and using a Preamble placed in the Preamble part of msg A.

[0167] The preamble is transmitted via a single antenna port. Therefore, if the data part is transmitted via multiple antenna ports, such as in MIMO or transmit diversity (e.g., SFBC), the base station cannot use the preamble for channel estimation, and channel estimation using a reference signal becomes necessary.

[0168] Thus, for example, whether or not the Preamble can be used for channel estimation depends on the number of antenna ports used to transmit the Data part. In other words, whether or not the Preamble can be used for channel estimation depends on whether or not the number of antenna ports used to transmit the Data part is the same as the number of antenna ports used to transmit the Preamble part. Alternatively, whether or not the Preamble can be used for channel estimation depends on whether or not the precoding between the Preamble part and the Data part is the same.

[0169] Therefore, in this embodiment, a method for controlling the configuration of the reference signal resources (e.g., the number of symbols or symbol positions, etc.) depending on whether or not the Preamble can be applied to channel estimation during demodulation and decoding of the Data part will be described.

[0170] [Device Configuration] Figure 16 is a block diagram showing the configuration of terminal 500 according to this embodiment. In Figure 16, components similar to those in Embodiment 1 (Figure 5) are denoted by the same reference numerals, and their descriptions are omitted.

[0171] In terminal 500, the Precoding determination unit 501 determines the precoding method for the Preamble part and Data part of msg A based on the downlink control information input from the demodulation / decoding unit 103. The Precoding determination unit 501 outputs precoding information indicating the determined precoding method for the Preamble part and Data part to the Preamble generation unit 105, the Data generation unit 108, and the reference signal generation unit 109.

[0172] The Preamble generation unit 105, the Data generation unit 108, and the Reference Signal Generation Unit 109 each control the precoding process of a signal (e.g., Preamble, data signal, or reference signal) based on the Precoding information input from the Precoding determination unit 501.

[0173] Furthermore, the Precoding determination unit 501 outputs information to the reference signal resource allocation control unit 502 indicating whether or not the precoding between the Preamble part and the Data part is the same.

[0174] An example of the method for determining the precoding in the precoding determination unit 501 will be described later.

[0175] The reference signal resource allocation control unit 502 controls the resources of the reference signal (for example, at least one of the number of symbols and the symbol positions) depending on whether the precoding between the Preamble part and the Data part is the same, as indicated in the information input from the Precoding determination unit 501. The reference signal resource allocation control unit 502 outputs information indicating the determined reference signal resources to the Data resource allocation unit 110. The Data resource allocation unit 110 allocates the reference signal to a resource based on this resource information.

[0176] An example of how the reference signal resource is determined in the reference signal resource allocation control unit 502 will be described later.

[0177] [Base station configuration] Figure 17 is a block diagram showing the configuration of the base station 600 according to this embodiment. In Figure 17, components similar to those in Embodiment 1 (Figure 6) are denoted by the same reference numerals, and their descriptions are omitted.

[0178] At the base station 600, the Precoding determination unit 601 determines whether the precoding between the Preamble part and the Data part of msg A is the same, based on the Preamble number input from the Preamble detection unit 206 and the control information input from the control information generation unit 201 (for example, information used by terminal 500 to transmit PRACH). The Precoding determination unit 601 outputs the determination result to the reference signal resource allocation control unit 602.

[0179] The reference signal resource allocation control unit 602 controls the resources of the reference signal (for example, at least one of the number of symbols and the symbol positions) according to whether the precoding is the same between the Preamble part and the Data part, as indicated by the information input from the Precoding determination unit 601. The reference signal resource allocation control unit 602 outputs information indicating the determined resources of the reference signal to the channel estimation unit 209. Based on this information, the channel estimation unit 209 identifies the resources to which the reference signal has been allocated.

[0180] [Operation of terminal 500 and base station 600] An example of operation in a terminal 500 and base station 600 having the above configuration will be described below.

[0181] Figure 18 is a sequence diagram showing an example of operation of terminal 500 (Figure 16) and base station 600 (Figure 17). In Figure 18, the same reference numerals are used for operations that are the same as in Embodiment 1 (see, for example, Figure 7), and their descriptions are omitted.

[0182] In Figure 18, terminal 500 determines, for example, the precoding method for the Preamble part and Data part of msg A based on upper layer signaling or downlink control information (DCI), and determines whether the precoding between the Preamble part and Data part is the same (ST301).

[0183] Terminal 500 determines the resource allocation of the reference signal (e.g., the number of symbols or the symbol position) depending on whether the precoding between the Preamble part and the Data part is the same (ST302).

[0184] Meanwhile, the base station 600 determines whether the precoding between the Preamble part and the Data part is the same based on the detected Preamble number and the information notified to the terminal 500 using upper-layer signaling or downlink control information (ST303). Then, based on the determination result, the base station 600 determines the resource allocation of the reference signal (e.g., the number of symbols or the symbol position) (ST304).

[0185] Next, an example of a method for determining (or deciding) the precoding in terminal 500 and base station 600, and an example of a method for controlling the resource allocation of the reference signal will be described.

[0186] [Method for determining and deciding on precoding] As mentioned above, the Preamble part has one antenna port.

[0187] Therefore, the Precoding determination unit 501 of the terminal 500 determines, for example, whether the precoding between the Preamble part and the Data part is the same, depending on the number of antenna ports applied to the transmission of the Data part of msg A. The number of antenna ports may be notified, for example, by upper-layer signaling.

[0188] For example, if the Data part has 1 antenna port, the Precoding determination unit 501 applies the same precoding method (e.g., random precoding or no precoding) to both the Preamble part and the Data part. Therefore, the Precoding determination unit 501 determines that the precoding between the Preamble part and the Data part is the same.

[0189] On the other hand, if the number of antenna ports in the Data part is greater than 1, the Precoding determination unit 501 applies different precoding methods to the Preamble part and the Data part. For example, the Precoding determination unit 501 applies random precoding or no precoding to the Preamble part, and SVD precoding or the like to the Data part. Therefore, the Precoding determination unit 501 determines that the precoding between the Preamble part and the Data part is not the same (in other words, different).

[0190] The Precoding determination unit 601 of the base station 600, similar to the Precoding determination unit 501, determines whether the precoding between the preamble part and the data part is the same, based on the number of antenna ports applied to the transmission of the data part of msg A notified to the terminal 500.

[0191] In the case of CFRA, terminal 500 may determine whether the precoding between the Preamble part and the Data part is the same based on the number of antenna ports notified by downlink control information (e.g., DCI), rather than by upper-layer signaling.

[0192] In this way, the terminal 500 and the base station 600 determine whether the precoding between the Preamble part and the Data part is the same based on the number of antenna ports in the Data part. For example, if the number of antenna ports in the Data part is greater than 1, the terminal 500 and the base station 600 determine that the precoding between the Preamble part and the Data part is different. This allows the base station 600 to determine whether the Preamble can be applied to channel estimation during demodulation and decoding of the Data part without additional signaling, thereby reducing the amount of signaling.

[0193] [Reference signal resource allocation control] The reference signal resource allocation control unit 502 of terminal 500 and the reference signal resource allocation control unit 602 of base station 600 change the configuration of the reference signal (for example, at least one of the number of symbols and the symbol position) depending on whether the precoding between the preamble part and the data part is the same.

[0194] <Method for determining the number of symbols in a reference signal> For example, terminal 500 and base station 600 set the number of symbols in the reference signal when the precoding between the Preamble part and the Data part is the same to be less than the number of symbols in the reference signal when the precoding between the Preamble part and the Data part is different.

[0195] For example, if the precoding between the Preamble part and the Data part is the same, terminal 500 and base station 600 set the number of symbols for the reference signal to "X-1". On the other hand, if the precoding between the Preamble part and the Data part is different, terminal 500 and base station 600 set the number of symbols for the reference signal to "X".

[0196] In this way, by changing the number of symbols in the reference signal depending on whether the precoding between the Preamble part and the Data part is the same or not, additional signaling to indicate the number of symbols becomes unnecessary, and the amount of signaling can be reduced.

[0197] Furthermore, if the precoding between the Preamble part and the Data part is identical, that is, if the base station 600 can use the Preamble part for channel estimation, throughput can be improved by reducing the number of symbols in the reference signal and increasing the resources to which data can be allocated. Note that when the base station 600 uses the Preamble part for channel estimation, even if the number of symbols in the reference signal is reduced, the performance degradation due to deterioration in channel estimation accuracy is small.

[0198] Furthermore, X may be notified from base station 600 to terminal 500 by quasi-static notification information or dynamic notification information (such as DCI), or it may be defined in the specifications as system common information and not be notified from base station 600 to terminal 500.

[0199] Furthermore, the difference in the number of symbols set depending on whether the precoding between the Preamble part and the Data part is the same (for example, the difference between X-1 and X) is not limited to one, but may be two or more.

[0200] <Method for determining the symbol placement of reference signals> For example, terminal 500 and base station 600 set the symbol position of the reference signal later when the precoding between the Preamble part and the Data part is the same, compared to the symbol position of the reference signal when the precoding between the Preamble part and the Data part is different.

[0201] In other words, when the precoding between the Preamble part and the Data part is the same, the symbol position of the reference signal is set further away from the symbol position of the Preamble part than when the precoding between the Preamble part and the Data part is different.

[0202] Figure 19A shows an example of the symbol location where a reference signal (e.g., DMRS) is placed when the precoding between the Preamble part and the Data part is the same. Figure 19B shows an example of the symbol location where a reference signal is placed when the precoding between the Preamble part and the Data part is different.

[0203] As shown in Figure 19A, when the precoding between the Preamble part and the Data part is the same, that is, when the Preamble can be used as a channel estimate during data demodulation at the base station 600, the reference signal of the Data part is positioned away from the symbol position of the Preamble part. This improves the time interpolation accuracy of channel estimation at the base station 600 and suppresses the degradation of channel estimation accuracy.

[0204] Furthermore, as shown in Figure 19B, if the precoding between the Preamble part and the Data part is different, that is, if the Preamble cannot be used as a channel estimate during data demodulation at the base station 600, the reference signal of the Data part is placed, for example, at the symbol position at the beginning of the data section. This allows the base station 600 to shorten the time required for data demodulation. Note that the symbol position of the reference signal of the Data part is not limited to the beginning of the Data part, as shown in Figure 19B.

[0205] Next, as an example, we will explain how to use the placement pattern table of the push reference signal (DMRS) specified in NR.

[0206] Figure 20 shows some of the DMRS placement patterns for PUSCH as defined in NR (e.g., PUSCH mapping type B).

[0207] In Figure 20, "Dmrs-AdditionalPosition" is, for example, the number of additional DMRS symbols notified by upper-layer signaling (2 in Figure 20). Also, in PUSCH mapping type B shown in Figure 20, symbol position "l0" is 0 (i.e., the first symbol of PUSCH; in other words, the front-loaded position).

[0208] For example, if the precoding between the Preamble part and the Data part is different, the symbol position of the reference signal is set to the position of the first symbol of PUSCH (front-loaded position). For example, the symbol position of the reference signal may be the first half of the symbol position of the reference signal defined as shown in Figure 20, enclosed by a solid line (for example, when the number of DMRS in the Data part is 1) or enclosed by a dotted line (when the number of DMRS in the Data part is 2).

[0209] Furthermore, for example, if the precoding between the Preamble part and the Data part is the same, the symbol position of the reference signal may skip the first DMRS symbol (e.g., symbol position l0) and apply the position of the next symbol onward (in other words, the latter half), as shown in the box enclosed by the dashed line in Figure 20 (for example, when the number of DMRS in the Data part is 1) or the box enclosed by the dashed line (when the number of DMRS in the Data part is 2).

[0210] The above describes the method for controlling resource allocation of reference signals.

[0211] Thus, in this embodiment, the terminal 500 and the base station 600 control the configuration of the reference signal of the Data part (e.g., symbol position or number of symbols) based on a precoding method, which is one of the parameters related to the transmission of the PRACH signal. This allows for appropriate control of the configuration of the reference signal of the Data part included in msg A (e.g., DMRS) in two-stage random access of NR, for example. Therefore, the terminal 500 can efficiently transmit the PRACH signal for two-stage random access according to the precoding method.

[0212] (Embodiment 4) Embodiment 3 described a method for controlling the resources of a reference signal (e.g., the number of symbols or symbol positions) according to the precoding (or number of antenna ports) applied to the transmission of the Data part of msg A. In contrast, this embodiment describes a method for controlling the resources of the reference signal of the Data part according to the resources of the preamble part of msg A (e.g., the preamble number or the time or frequency resources of the preamble).

[0213] [Device Configuration] Figure 21 is a block diagram showing the configuration of the terminal 700 according to this embodiment. In Figure 21, components similar to those in Embodiment 1 (Figure 5), Embodiment 2 (Figure 8), or Embodiment 3 (Figure 16) are denoted by the same reference numerals, and their descriptions are omitted.

[0214] In terminal 700, the RACH configuration table 701 is a table in which Preamble numbers are grouped according to whether or not the precoding is the same between the Preamble part and the Data part of msg A (hereinafter sometimes simply referred to as "precoding consistency"). The information contained in the RACH configuration table 701 may be notified to terminal 700 from base station 800 (described later) by, for example, quasi-static notification information (e.g., upper-layer signaling) or dynamic notification information (e.g., DCI). Alternatively, the information contained in the RACH configuration table 701 may be specified in the specifications as system common information and may not be notified to terminal 700 from base station 800.

[0215] The information contained in the RACH setting table 701 is output to, for example, the Preamble number selection unit 702 and the Precoding determination unit 703. An example of the RACH setting table 701 will be described later.

[0216] The Preamble number selection unit 702 selects the Preamble number to be used for PRACH transmission. The Preamble number selection unit 702 outputs Preamble information indicating the selected Preamble number to the Preamble generation unit 303 and the Precoding determination unit 703.

[0217] For example, if the RACH type is CBRA, the Preamble number selection unit 702 refers to the RACH setting table 701 and randomly selects one Preamble number from among the Preamble numbers included in the group (Preamble number group) associated with the precoding consistency. On the other hand, if the RACH type is CFRA, the Preamble number selection unit 702 selects the Preamble number notified by the downlink control information input from the demodulation / decoding unit 103. An example of how the Preamble number selection unit 702 selects a Preamble number will be described later.

[0218] The Precoding determination unit 703 refers to the RACH setting table 701 and determines whether the precoding between the Preamble part and the Data part is the same (precoding consistency) based on the Preamble number indicated in the Preamble information input from the Preamble number selection unit 702. The Precoding determination unit 703 also determines the precoding method to be applied to the Preamble and Data parts.

[0219] The Precoding determination unit 703 outputs the determined precoding method to the Preamble generation unit 303, the Data generation unit 108, and the reference signal generation unit 109. The Precoding determination unit 703 also outputs information to the reference signal resource allocation control unit 502 indicating whether the precoding between the Preamble part and the Data part is the same.

[0220] Similar to Embodiment 3, the reference signal resource allocation control unit 502 determines the reference signal resource based on information input from the Precoding determination unit 703 indicating whether the precoding between the Preamble part and the Data part is the same. In this embodiment, the reference signal resource allocation control unit 502 may also determine the reference signal resource using the Preamble number input from the Preamble number selection unit 702 and the information contained in the RACH setting table 701.

[0221] [Base station configuration] Figure 22 is a block diagram showing the configuration of the base station 800 according to this embodiment. In Figure 22, components similar to those in Embodiment 1 (Figure 6), Embodiment 2 (Figure 9), or Embodiment 3 (Figure 17) are denoted by the same reference numerals, and their descriptions are omitted.

[0222] In base station 800, the RACH configuration table 801 is a table in which Preamble numbers are grouped according to whether or not the precoding is the same between the Preamble part and the Data part of msg A (in other words, precoding consistency), similar to the RACH configuration table 701 held by terminal 700. The information contained in the RACH configuration table 801 is output to, for example, the Precoding determination unit 802. An example of the RACH configuration table 801 will be described later.

[0223] The Precoding determination unit 802 refers to the RACH setting table 801 and determines whether the precoding is the same between the Preamble part and the Data part of msg A, based on the Preamble number input from the Preamble detection unit 206. The Precoding determination unit 802 outputs the determination result to the reference signal resource allocation control unit 602.

[0224] Similar to Embodiment 3, the reference signal resource allocation control unit 602 determines the reference signal resource based on information input from the Precoding determination unit 802 indicating whether the precoding between the Preamble part and the Data part is the same. In this embodiment, the reference signal resource allocation control unit 602 may also determine the reference signal resource using the Preamble number input from the Preamble detection unit 206 and the information contained in the RACH setting table 801.

[0225] [Operation of Terminal 700 and Base Station 800] An example of operation in a terminal 700 and base station 800 having the above configuration will be described below.

[0226] Figure 23 is a sequence diagram showing an example of operation of terminal 700 (Figure 21) and base station 800 (Figure 22). In Figure 23, the same reference numerals are used for operations that are the same as those in Embodiment 1 (see, for example, Figure 7), Embodiment 2 (see, for example, Figure 10), or Embodiment 3 (see, for example, Figure 18), and their descriptions are omitted.

[0227] In Figure 23, terminal 700 selects a Preamble number for msg A (ST401). For example, in the case of CBRA, terminal 700 refers to the RACH setting table 701 and randomly selects one Preamble number from the group of Preamble numbers corresponding to the precoding method of the Preamble part and Data part of msg A. In the case of CFRA, terminal 700 selects a Preamble number notified by the downlink control information (DCI).

[0228] Terminal 700 refers to the RACH configuration table 701 and determines whether the precoding determined between the Preamble part and the Data part is the same based on the selected Preamble number (ST402).

[0229] Meanwhile, the base station 800 refers to the RACH configuration table 801 and determines whether the precoding determined between the Preamble part and the Data part is the same based on the detected Preamble number (ST403).

[0230] Next, an example of a method for determining (or deciding) the precoding in terminal 700 and base station 800, and an example of a method for controlling the resource allocation of the reference signal will be described.

[0231] Next, we will describe examples of the configuration of RACH configuration tables 701 and 801, and examples of the operation of terminal 700 and base station 800.

[0232] <Example of operation 1> Figure 24 shows an example of RACH setting tables 701 and 801 in operation example 1. As shown in Figure 24, RACH setting tables 701 and 801 are tables that associate the Preamble number of the Preamble part of msg A with whether or not the precoding between the Preamble part and the Data part of msg A is the same (hereinafter sometimes simply referred to as precoding consistency).

[0233] The Preamble number selection unit 702 of terminal 700, for example in the case of CBRA, uses at least one of the following pieces of information about terminal 700 to determine whether or not to make the precoding between the Preamble part and the Data part of msg A the same. (1) Number of antenna ports in the data part (2) Difference between the required quality of the Data part and the required quality of the Preamble part (3) UE Capability (e.g., number of transmitting antennas)

[0234] The required quality of the Data part may be determined, for example, from the configured MCS. Similarly, the required quality of the Preamble part may be determined, for example, from the Preamble format. Furthermore, the parameters used to determine whether or not to make the precoding between the Preamble part and the Data part of msg A the same are not limited to the information described above; other information may also be used.

[0235] The Preamble number selection unit 702, for example, refers to the RACH setting table 701 shown in Figure 24 and randomly selects one Preamble number from among the Preamble numbers included in each group, depending on whether the precoding between the Preamble part and the Data part of msg A is the same.

[0236] For example, if the precoding between the Preamble part and the Data part of msg A is the same, the Preamble number selection unit 702 selects one Preamble number from Preamble numbers 0 and 1 included in Group A shown in Figure 24. Also, for example, if the precoding between the Preamble part and the Data part of msg A is different, the Preamble number selection unit 702 selects one Preamble number from Preamble numbers 2 to 4 included in Group B shown in Figure 24.

[0237] On the other hand, the Preamble number selection unit 702 selects, for example, in the case of CFRA, a Preamble number included in the DCI notified by the base station 800.

[0238] The Precoding determination unit 703 of terminal 700 refers to the RACH setting table 701 and determines whether the precoding is the same between the Preamble part and the Data part of msg A, based on the Preamble number selected in the Preamble number selection unit 702. For example, in Figure 24, if Preamble number 1 is selected in the Preamble number selection unit 702, the Precoding determination unit 703 determines that the precoding is the same between the Preamble part and the Data part of msg A. The same applies when the Preamble number selected in the Preamble number selection unit 702 is any other number.

[0239] In operation example 1, the Preamble number selection unit 702 determines whether the precoding is the same between the Preamble part and the Data part of msg A, so the Precoding determination unit 703 may apply the determination result from the Preamble number selection unit 702 as is.

[0240] Furthermore, the Precoding determination unit 802 of the base station 800 refers to the RACH setting table 801 and determines whether the precoding is the same between the Preamble part and the Data part of msg A based on the Preamble number detected by the Preamble detection unit 206. For example, in Figure 24, if Preamble number 1 is detected by the Preamble detection unit 206, the Precoding determination unit 802 determines that the precoding is the same between the Preamble part and the Data part of msg A. The same applies when the Preamble number detected by the Preamble detection unit 206 is any other number.

[0241] Furthermore, the reference signal resource allocation control unit 502 of the terminal 700 and the reference signal resource allocation control unit 602 of the base station 800 control the reference signal resources (for example, at least one of the number of symbols and the symbol positions) depending on whether the precoding between the Preamble part and the Data part is the same, similar to the third embodiment.

[0242] Thus, in Operation Example 1, the Preamble number of the Preamble part of msg A is associated with the consistency of the precoding between the Preamble part and the Data part. This eliminates the need for control information to notify about the consistency of the precoding, thereby reducing the amount of signaling.

[0243] Furthermore, the base station 800 can recognize the difference in precoding between the Preamble part and Data part selected by the terminal 700 (in other words, the consistency of precoding) when detecting the Preamble (e.g., Preamble number). Therefore, in CBRA, the precoding between the Preamble part and Data part can be changed for each terminal 700. Thus, according to example 1, for example, precoding control can be optimized according to the reception quality or UE capability of each terminal 700, and the reception performance of the Data part can be improved.

[0244] Furthermore, the same effects as in Embodiment 3 can be obtained by changing the resources of the reference signal (e.g., the number of DMRS symbols and the DMRS symbol positions) based on the consistency between the Preamble number of the Preamble part of msg A and the precoding between the Preamble part and the Data part.

[0245] Note that the table shown in Figure 24 is just one example and is not limited to the association between Preamble numbers and ranks shown in Figure 24.

[0246] <Example of operation 2> Figure 25 shows an example of RACH setting tables 701 and 801 in operation example 2. As shown in Figure 25, RACH setting tables 701 and 801 are tables that associate the Preamble number of the Preamble part of msg A, the precoding consistency between the Preamble part and the Data part of msg A, and the number of symbols of the reference signal (e.g., DMRS).

[0247] The Preamble number selection unit 702 of terminal 700 identifies (in other words, narrows down) the group of Preamble numbers depending on whether the precoding between the Preamble part and the Data part is the same, for example, as in operation example 1. For example, in Figure 25, if the precoding between the Preamble part and the Data part is different, the Preamble number selection unit 702 narrows down the group to groups C and D.

[0248] Subsequently, the Preamble number selection unit 702 determines the number of DMRS symbols using, for example, at least one of the following pieces of information regarding the terminal 700. (1) Movement speed of terminal 700 (2) MCS (3) Rank

[0249] For example, if the terminal 700 is moving at a high speed (for example, if the movement speed is above a threshold), the Preamble number selection unit 702 sets a larger number of DMRS symbols to improve the time interpolation accuracy by increasing the number of symbols in the reference signal. Also, for example, if the MCS of the Data part of msg A is high (for example, if the MCS is above a threshold), or if the rank of the Data part of msg A is high (for example, if the rank is above a threshold), the Preamble number selection unit 702 sets a larger number of DMRS symbols to improve the channel estimation accuracy. Note that the parameters for determining the number of DMRS symbols are not limited to movement speed, MCS, and rank, but may also be other parameters.

[0250] For example, in Figure 25, if the precoding differs between the Preamble part and the Data part, and the number of DMRS symbols is large (for example, 2), the Preamble number selection unit 702 randomly selects one Preamble number from among the Preamble numbers included in group D.

[0251] Thus, in Operation Example 2, similar to Operation Example 1, the Preamble number of the Preamble part of msg A is associated with the consistency of the precoding between the Preamble part and the Data part. This eliminates the need for control information to notify whether the precodings are identical or not, thereby reducing the amount of signaling.

[0252] Furthermore, in operation example 2, the number of symbols in the reference signal can be set according to the movement speed of terminal 700, MCS, or rank, so the reception performance of msg A Data part can also be improved in CBRA.

[0253] Note that the table shown in Figure 25 is just an example, and the relationship between the Preamble number shown in Figure 25, whether the precoding of the Preamble part and the Data part are the same, and the number of DMRS symbols is not limited to this. For example, Figure 25 shows the case with three types of DMRS symbols, but the number of DMRS symbols may be two or four or more. Also, the number of Preamble number groups may be five or more.

[0254] Also, for example, as shown in FIG. 26, the RACH configuration tables 701 and 801 may be tables that associate the Preamble number of the Preamble part of msg A, the consistency of the precoding between the Preamble part and the Data part of msg A, the number of symbols of the DMRS, and the moving speed (or MCS or rank) of the terminal 700. Note that the determination criterion for the moving speed (the criterion for determining whether the moving speed is fast or slow. For example, a threshold value) may be defined in the specification, for example, or may be notified by quasi-static notification information such as upper layer signaling, or dynamic notification information such as DCI.

[0255] Above, the operation examples 1 and 2 have been described.

[0256] Thus, in this embodiment, the terminal 700 and the base station 800 control the configuration (for example, the number of symbols) of the reference signal of the Data part based on the resource (for example, the Preamble number) of the Preamble part, which is one of the parameters related to the transmission of the PRACH signal. Thereby, for example, in the two-step random access of NR, the configuration (for example, the number of symbols of the DMRS) of the reference signal of the Data part included in msg A can be appropriately controlled. Therefore, for example, the terminal 700 can efficiently transmit the PRACH signal for two-step random access according to the resource of the Preamble part.

[0257] Above, each embodiment of the present disclosure has been described.

[0258] (Other Embodiments) (1) In the above embodiment, the PRACH has been described as an example of the transmission signal. However, the transmission signal is not limited to the PRACH. For example, it may be other signals transmitted from a terminal (corresponding to a transmitting device) to a base station (corresponding to a receiving device), or a transmission signal transmitted from a base station (corresponding to a transmitting device) to a terminal (corresponding to a receiving device).

[0259] (2) Also, the embodiments may be applied in combination. For example, by combining Embodiment 1 and Embodiment 2, as shown in FIG. 27, a defined table associating the RACH type, the preamble number, and the rank number of the Data part of msg A may be used. In this case, the maximum rank number may be set to 1 in CBRA, and a value greater than 1 may be set as the maximum rank in CFRA.

[0260] (3) Also, in the above embodiments, DMRS is used as an example of the reference signal, but the reference signal is not limited to DMRS. For example, the reference signal may be SRS (Sounding Reference Signal) or PT-RS (Phase Tracking Reference Signal).

[0261] The above has described other embodiments.

[0262] This disclosure can be implemented as software, hardware, or software in conjunction with hardware. Each functional block used in the description of the above embodiments may be implemented partially or entirely as an integrated circuit (LSI), and each process described in the above embodiments may be controlled partially or entirely by a single LSI or a combination of LSIs. An LSI may consist of individual chips, or it may consist of a single chip that includes some or all of the functional blocks. An LSI may have data inputs and outputs. Depending on the degree of integration, LSIs may be referred to as ICs, system LSIs, super LSIs, or ultra LSIs. The method of integrated circuit implementation is not limited to LSIs, and may also be implemented with dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, an FPGA (Field Programmable Gate Array) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. This disclosure may be implemented as digital processing or analog processing. Furthermore, if advancements in semiconductor technology or other derived technologies lead to the emergence of integrated circuit technologies that replace LSIs, then naturally, it would be possible to use those technologies to integrate functional blocks. The application of biotechnology, for example, is a possibility.

[0263] This disclosure is applicable to all types of devices, systems, and equipment with communication capabilities (collectively referred to as communication devices). Non-exclusive examples of communication devices include telephones (mobile phones, smartphones, etc.), tablets, personal computers (PCs) (laptops, desktops, notebooks, etc.), cameras (digital still / video cameras, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, digital book readers, telehealth and telemedicine devices, vehicles or mobile transport with communication capabilities (automobiles, airplanes, ships, etc.), and combinations of the above-mentioned devices.

[0264] Communication devices are not limited to portable or movable devices, but also include all kinds of non-portable or fixed devices, devices, and systems, such as smart home devices (appliances, lighting equipment, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0265] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0266] Furthermore, the communication device also includes devices such as controllers and sensors that are connected to or linked to a communication device that performs the communication functions described in this disclosure. For example, this includes controllers and sensors that generate control signals and data signals used by the communication device that performs the communication functions of the communication device.

[0267] Furthermore, communication equipment includes infrastructure facilities such as base stations, access points, and any other devices, devices, and systems that communicate with or control the aforementioned non-limited types of equipment.

[0268] A transmitting device according to one embodiment of the present disclosure comprises a transmitting circuit that transmits a random access signal including at least a data section, and a control circuit that controls the configuration of the data section based on parameters relating to the transmission of the random access signal.

[0269] In a transmitting device according to one embodiment of the present disclosure, the control circuit controls the resources of a reference signal for demodulating the signal of the data section based on the type of random access procedure.

[0270] In a transmitting device according to one embodiment of the present disclosure, the control circuit controls the resources for a reference signal to demodulate the signal of the data section based on the resources used for transmitting the random access signal.

[0271] In a transmitting device according to one embodiment of the present disclosure, the control circuit controls the resources of a reference signal for demodulating the signal of the data section based on whether the first precoding of the preamble section included in the random access signal and the second precoding of the data section are the same.

[0272] In a transmitting device according to one embodiment of the present disclosure, the resource of the reference signal is the number of symbols of the reference signal, and the number of symbols when the first precoding and the second precoding are the same is less than the number of symbols when the first precoding and the second precoding are different.

[0273] In a transmitting device according to one embodiment of the present disclosure, the resource of the reference signal is the symbol position of the reference signal, and the symbol position when the first precoding and the second precoding are the same is later than the symbol position when the first precoding and the second precoding are different.

[0274] In a transmitting device according to one embodiment of the present disclosure, if the number of antenna ports used for the signal of the data section is greater than 1, the first precoding and the second precoding are different.

[0275] In a transmitting device according to one embodiment of the present disclosure, the control circuit determines whether the first precoding and the second precoding are the same based on the resources of the preamble section.

[0276] A receiving apparatus according to an embodiment of the present disclosure includes a receiving circuit that receives a random access signal including at least a data part, and a control circuit that controls the configuration of the data part based on parameters related to the transmission of the random access signal.

[0277] A transmission method according to an embodiment of the present disclosure transmits a random access signal including at least a data part, and controls the configuration of the data part based on parameters related to the transmission of the random access signal.

[0278] A receiving method according to an embodiment of the present disclosure receives a random access signal including at least a data part, and controls the configuration of the data part based on parameters related to the transmission of the random access signal.

[0279] The disclosures of the specification, drawings, and abstracts included in Japanese Application No. 2018-247260 filed on December 28, 2018 are all incorporated herein by reference.

Industrial Applicability

[0280] An embodiment of the present disclosure is useful in a mobile communication system.

Explanation of Signs

[0281] 100, 300, 500, 700 Terminal 101, 204 Antenna 102, 205 Radio Receiving Unit 103 Demodulation and Decoding Unit 104, 207 RACH type Determination Unit 105, 303 Preamble Generation Unit 106 Preamble Resource Allocation Unit 107, 208, 304, 402 Rank Determination Unit 108 Data Generation Unit 109 Reference Signal Generation Unit 110 Data Resource Allocation Unit 111, 203 Radio Transmission Unit 200, 400, 600, 800 Base Station 201 Control Information Generation Unit 202 Encoding and Modulation Section 206 Preamble detection unit 209 Channel Estimation Unit 210 Data Demodulation / Decoding Unit 301,401,701,801 RACH configuration table 302,702 Preamble number selection section 501,703 Precoding decision section 502,602 Reference Signal Resource Allocation Control Unit 601,802 Precoding judgment section

Claims

1. An integrated circuit for controlling a transmitting device, A transmitting circuit that transmits a random access signal including the preamble and data sections in Message A, In Message A, one preamble number is randomly selected from among the preamble numbers included in the group corresponding to the number of antenna ports applied to the data section, and a portion of the preamble numbers are included in group A corresponding to the first number of antenna ports, and the other preamble numbers are included in group B corresponding to the second number of antenna ports, and the control circuit is... An integrated circuit comprising the following features.

2. The control circuit controls the resources of the reference signal for demodulating the signal of the data section based on the type of random access procedure. The integrated circuit according to claim 1.

3. The control circuit controls the resources for a reference signal to demodulate the data section signal based on the resources used for transmitting the random access signal. The integrated circuit according to claim 1.

4. The control circuit controls the resources of the reference signal for demodulating the signal of the data section based on whether the first precoding of the preamble section included in the random access signal and the second precoding of the data section are the same. The integrated circuit according to claim 1.

5. The resource of the reference signal is the number of symbols of the reference signal, The number of symbols when the first precoding and the second precoding are the same is less than the number of symbols when the first precoding and the second precoding are different. The integrated circuit according to claim 4.

6. The resource of the reference signal is the symbol position of the reference signal, When the first precoding and the second precoding are the same, the symbol position is later than when the first precoding and the second precoding are different. The integrated circuit according to claim 4.

7. If the number of antenna ports used for the signal of the data section is greater than one, the first precoding and the second precoding are different. The integrated circuit according to claim 4.

8. The control circuit determines, based on the resources of the preamble section, whether the first precode and the second precode are the same. The integrated circuit according to claim 4.

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