Communication devices, communication methods, and integrated circuits

Abstract

The present invention provides a communication device, a communication method, and an integrated circuit that appropriately perform random access processing. [Solution] In a communication system, the terminal comprises a control unit that selects a random access preamble from a first set of multiple random access preambles when the path loss between the terminal and the base station is less than a threshold, and selects a random access preamble from a second set of multiple random access preambles when the path loss between the terminal and the base station is greater than or equal to a threshold, and a wireless transmission unit that transmits the selected random access preamble, wherein the first set of multiple interlace numbers associated with the first set of multiple random access preambles are consecutive, the second set of multiple interlace numbers associated with the second set of multiple random access preambles are consecutive, and the first set of multiple interlace numbers is different from the second set of multiple interlace numbers.

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] In NR, similar to LTE-LAA (License-Assisted Access), operation in an unlicensed band is being discussed. In LTE-LAA, operation in an unlicensed band that is problematic for operation in a licensed band is supported. On the other hand, in NR, it is required to realize operation (Stand-alone operation) in an unlicensed band without using a licensed band.

[0004] Therefore, in NR, the introduction of the Physical Random Access Channel (PRACH), which is used by a terminal (also called UE: User Equipment) for initial connection to a base station (also called gNB), into an unlicensed band is being considered (for example, see Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

[0006] However, random access methods in NR have not been sufficiently investigated.

[0007] Non-limiting embodiments of this disclosure contribute to providing a transmitter, receiver, transmission method, and reception method that can appropriately perform random access processing.

[0008] A transmitting device according to one embodiment of the present disclosure comprises a transmitting circuit for transmitting a data signal and a control circuit for determining a second resource to be used for transmitting the data signal based on a first resource used for transmitting a preamble signal.

[0009] A receiving device according to one embodiment of the present disclosure comprises a receiving circuit for receiving a data signal and a control circuit for determining the resources used for transmitting the data signal based on the resources used for transmitting the preamble signal.

[0010] A transmission method according to one embodiment of the present disclosure determines the resources to be used for transmitting a data signal based on the resources used for transmitting a preamble signal, and transmits the data signal.

[0011] A receiving method according to one embodiment of the present disclosure determines the resources used for transmitting a data signal based on the resources used for transmitting a preamble signal, and receives the data signal.

[0012] 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.

[0013] According to one embodiment of the present disclosure, random access processing can be performed appropriately.

[0014] Further advantages and effects of one aspect 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]

[0015] [Figure 1] A diagram illustrating an example of a random access procedure. [Figure 2] A diagram showing an example of a block-based interlace design. [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 example of operation of the terminal and base station according to Embodiment 1. [Figure 8] This figure shows an example of the correspondence between transmission resources between the Preamble part and the Data part according to Derivation Example 1 of Embodiment 1. [Figure 9] A diagram showing an example of transmission resource allocation according to derivation example 1 of Embodiment 1. [Figure 10] This figure shows another example of the correspondence between transmission resources between the Preamble part and the Data part according to Derivation Example 1 of Embodiment 1. [Figure 11] This figure shows an example of the correspondence between transmission resources between the Preamble part and the Data part according to the derivation example 2 of Embodiment 1. [Figure 12]Figure showing an example of transmission resource allocation according to Derived Example 2 of Embodiment 1 [Figure 13] Figure showing an example of the correspondence relationship between the transmission resources of the Preamble part and the Data part according to Derived Example 3 of Embodiment 1 [Figure 14] Figure showing an example of transmission resource allocation according to Derived Example 3 of Embodiment 1 [Figure 15] Figure showing an example of the correspondence relationship between the transmission resources of the Preamble part and the Data part according to Derived Example 4 of Embodiment 1 [Figure 16] Figure showing an example of transmission resource allocation according to Derived Example 4 of Embodiment 1 [Figure 17] Figure showing an example of the correspondence relationship between the transmission resources of the Preamble part and the Data part according to Derived Example 5 of Embodiment 1 [Figure 18] Figure showing an example of transmission resource allocation according to Derived Example 5 of Embodiment 1 [Figure 19] Figure showing an example of the correspondence relationship between the transmission resources of the Preamble part and the Data part according to Derived Example 6 of Embodiment 1 [Figure 20] Figure showing an example of transmission resource allocation according to Derived Example 6 of Embodiment 1 [Figure 21] Figure showing an example of the correspondence relationship between the transmission resources of the Preamble part and the Data part according to Derived Example 7 of Embodiment 1 [Figure 22] Figure showing an example of transmission resource allocation according to Derived Example 7 of Embodiment 1

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0017] [Random Access Procedure] For example, random access procedures in the license bandwidth are implemented using a four-step random access method (also known as 4-step RACH (Random Access Channel) or 4-Step CBRA (Contention Based Random Access)).

[0018] In a four-stage random access (RRC) system, for example, as shown in Figure 1(a), the terminal (UE) sends a Preamble to the base station (gNB) as the first stage transmission (MSG1). After receiving and decoding MSG1, the base station notifies the terminal of scheduling information, including the response to the Preamble (RA response) and the uplink transmission timing of MSG3, as the second stage transmission (MSG2). After receiving and decoding MSG2, the terminal notifies the base station of RRC connection request information, such as information about the terminal (e.g., terminal ID), as the third stage transmission (MSG3), using the scheduling information instructed in MSG2. Finally, the base station notifies the terminal of control information for the terminal to establish an RRC connection or control information for contention resolution as the fourth stage transmission (MSG4). The control information for contention resolution is, for example, a control signal notified by the terminal. In Contention Resolution, for example, a terminal compares the control signal it sent with the control information for Contention Resolution contained in MSG4. If the information is not identical, it restarts from MSG1 to avoid RACH collisions between multiple terminals.

[0019] On the other hand, the introduction of a two-step random access procedure (also called 2-step RACH or 2-Step CBRA) is being considered as a random access procedure in the unlicensed bandwidth of NR (see, for example, Non-Patent Document 1).

[0020] In two-stage random access, for example, as shown in Figure 1(b), the terminal transmits a Preamble part (corresponding to the Preamble (or MSG1) in Figure 1(a)) and a Data part (corresponding to MSG3 in Figure 1(a)) to the base station as the first stage transmission (MSG1). The terminal may transmit the Preamble part and the Data part simultaneously, over a continuous period of time, or within a specified time (for example, within one slot).

[0021] Next, as shown in Figure 1(b), after receiving and decoding MSG1, the base station sends a second transmission (MSG2) to the terminal containing the uplink transmission timing and control information for RRC connection on the terminal side or control information for contention resolution (corresponding to MSG2 and MSG4 in Figure 1(a)).

[0022] By introducing two-stage random access in the unlicensed NR bandwidth, it is expected that effects such as reducing LBT (Listen Before Talk) processing or reducing random access latency will be achieved. Furthermore, the introduction of two-stage random access is not limited to the unlicensed bandwidth. For example, it is being considered to reduce data transmission latency by repurposing two-stage random access in the licensed bandwidth and applying it to URLLC (Ultra-Reliable and Low Latency Communications) services.

[0023] [PRACH] For example, a PRACH for four-stage random access used in the NR license band (e.g., MSG1 in Figure 1(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 (e.g., a Cyclic-shifted Zadoff-Chu (CS-ZC) sequence). The CP is a signal that copies a portion of the Preamble. The GP is a non-transmission period. Note that the Preamble is not limited to the CS-ZC sequence; any code sequence with good correlation characteristics is acceptable.

[0024] Information about these PRACHs is notified to the terminals, for example, as cell information from the base station. For example, a different CS-ZC sequence is uniquely associated with each Preamble number. The terminal transmits the CS-ZC sequence corresponding to a randomly selected Preamble number as the Preamble. For example, even if multiple terminals transmit PRACHs 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 sequences.

[0025] [B-IFDMA] As one method for allocating frequency resources for PRACH (e.g., MSG1 in Figure 1(a)), which is a four-stage random access channel in the unlicensed band, the application of a block-based interlace design (also called B-IFDMA (Block-interleaved Frequency Division Multiple Access)) is being considered (see, for example, Non-Patent Document 2).

[0026] Figure 2 shows an example of a block-based interlace design.

[0027] Block-based interlace design is used in the frequency resource allocation method for PUSCH (Physical Uplink Shared Channel) in LTE-LAA. B-IFDMA is a method of transmitting signals using a bandwidth called interlace, which is uniformly distributed in the frequency direction within the system bandwidth, in order to comply with the Occupied Channel Bandwidth (OCB) limit of the unlicensed band and mitigate the effects of the Power Spectral Density (PSD) limit.

[0028] Interlace is composed of consecutive subcarrier groups (continuous blocks of frequency resources, e.g., 1PRB (Physical Resource Block)). For example, multiple interlaces are contained within a bandwidth obtained by dividing the system bandwidth or a portion of the system bandwidth (e.g., BWP (Bandwidth Part)) into multiple blocks (hereinafter referred to as a cluster or cluster block). Each interlace contained in each cluster is assigned a number (hereinafter referred to as the "interlace number").

[0029] Note that "cluster" has a similar meaning to "interval" where interlaces with the same interlace number are placed. In other words, interlaces with the same interlace number are uniformly distributed in the frequency direction across multiple cluster blocks.

[0030] Furthermore, a cluster may be defined not only as a bandwidth obtained by dividing the system bandwidth into multiple blocks, but also as a bandwidth obtained by dividing a certain bandwidth (for example, the bandwidth in which LBT (listen before talk) is implemented, a 20MHz bandwidth, or a bandwidth that is an integer multiple of 20MHz, etc.) into multiple blocks.

[0031] For example, in the example in Figure 2, the five interlaces within a cluster that divides a certain bandwidth are assigned interlace numbers interlace#0, #1, #2, #3, and #4. Also in Figure 2, each cluster is assigned a cluster number Cluster#0, #1, #2, #3, ...

[0032] For example, let's consider the case where a single interlace number (interlace#0 in Figure 2) is set for the PRACH transmission resource, as shown in Figure 2. For instance, if terminal A (UE#A) and terminal B (UE#B) each select different Preamble numbers (e.g., different CS-ZC sequences (ZC#X and ZC#Y)), the Preambles transmitted from terminal A and terminal B will be code-multiplexed.

[0033] Incidentally, the allocation of two-stage random access radio resources in the unlicensed NR band has not been adequately discussed. In particular, the allocation of radio resources for the Data part of MSG1 (see, for example, Figure 1(b)) when applying a Block-based interlace design (see, for example, Figure 2) to the Preamble part of MSG1 has not been discussed.

[0034] As described above, when a block-based interlace design is applied to the radio resource allocation method for the Preamble part in two-stage random access, different code sequences (e.g., CS-ZC sequences) are used for the Preambles of multiple terminals, each generated from a different Preamble number. This allows for code multiplexing of the Preambles of multiple terminals using the same interlace number frequency resource.

[0035] On the other hand, the Data part in two-stage random access contains several tens of bits of transmission information, such as a terminal-specific ID, and therefore contains more information than the Preamble part. For this reason, it is difficult to apply the same code multiplexing to the Data part as to the Preamble part.

[0036] For example, if a different CS-ZC sequence is uniquely associated with each transmission information pattern in the Data part, the number of CS-ZC sequences that can be associated with the transmission information pattern may exceed the number of sequences that can be generated. This also leads to challenges such as increased processing load in the base station's correlation detection or deterioration of detection performance.

[0037] Therefore, the following describes how to appropriately allocate wireless resources in the Data part when a terminal transmits PRACH in two-stage random access.

[0038] 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 predetermined 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.

[0039] (Embodiment 1) [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 108 transmits a data signal (e.g., a Data part). The control unit 101 determines a second resource to be used for transmitting the data signal based on a first resource (e.g., a code sequence corresponding to a Preamble number) used for transmitting a preamble signal (e.g., a Preamble part).

[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 202 receives a data signal (e.g., a Data part). The control unit 203 determines the resources to be used to transmit the data signal based on the resources used to transmit the preamble signal (e.g., a code sequence corresponding to a Preamble number).

[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 a control unit 101, a Preamble generation unit 104, a Preamble resource allocation unit 105, a Data generation unit 106, a Data resource allocation unit 107, a wireless transmission unit 108, an antenna 109, a wireless reception unit 110, and a demodulation / decoding unit 111.

[0044] The control unit 101 determines, for example, the wireless resources to which PRACH is allocated (for example, the allocation resources for the Preamble part and Data part included in MSG1 in two-stage random access). For example, the control unit 101 includes a Preamble resource setting unit 102 and a Data resource setting unit 103.

[0045] The Preamble resource setting unit 102 determines candidate transmission resources to be assigned to the Preamble part based on PRACH transmission resource information (also called Random access configuration), which indicates the PRACH transmission resources available within the cell of the base station 200. The transmission resources for the Preamble include, for example, frequency resources indicating a frequency band represented by an interlace number and a cluster number, or time resources such as transmission timing. Furthermore, the candidate transmission resources to be assigned to the Preamble part are uniquely associated with, for example, a Preamble number.

[0046] The Preamble resource setting unit 102 randomly selects one Preamble number from a group of Preamble numbers that includes at least one Preamble number, and outputs the selected Preamble number and information indicating the transmission resource associated with that Preamble number to the Data resource setting unit 103, the Preamble generation unit 104, and the Preamble resource allocation unit 105.

[0047] The PRACH transmission resource information available to terminal 100 includes, for example, PRACH-related configuration information such as the Preamble series number, CS amount, PRACH time resource (e.g., period), PRACH frequency resource location, and Preamble format number. Furthermore, the PRACH transmission resource information is included in the control information broadcast from the connected base station 200 (e.g., serving cell) and is notified to terminal 100 in advance. Some of the PRACH transmission resource information may be, for example, system-common information defined in the specifications, and does not need to be notified to terminal 100 from base station 200.

[0048] The Data resource setting unit 103 determines the transmission resources for the Data part based on the transmission resources for the Preamble part input from the Preamble resource setting unit 102. For example, the Data resource setting unit 103 sets the transmission resources for the Data part based on the Preamble number input from the Preamble resource setting unit 102. The transmission resources for the Data part include, for example, frequency resources represented by the interlace number and cluster number, or time resources such as transmission timing. The Data resource setting unit 103 outputs information indicating the set transmission resources to the Data resource allocation unit 107. Details of how the Data resource setting unit 103 derives the transmission resources for the Data part will be described later.

[0049] The Preamble generation unit 104 generates a CS-ZC sequence using information indicating the transmission resource input from the Preamble resource setting unit 102 (for example, the sequence number and cyclic shift amount corresponding to the selected Preamble number), and outputs the generated CS-ZC sequence as a Preamble part signal (or preamble signal) to the Preamble resource allocation unit 105. Here, if the Preamble number selected in the Preamble resource setting unit 102 is different, the Preamble generation unit 104 generates different code sequences (CS-ZC sequences, etc.) that are orthogonal or have low correlation.

[0050] The Preamble resource allocation unit 105 assigns the Preamble part signals input from the Preamble generation unit 104 to the transmission resource information (for example, frequency resources corresponding to the cluster number and interlace number) input from the Preamble resource setting unit 102. The Preamble resource allocation unit 105 also outputs the Preamble part signals to the wireless transmission unit 108 based on the transmission timing indicated in the transmission resource information input from the Preamble resource setting unit 102.

[0051] The Data generation unit 106 generates a data signal (for example, equivalent to MSG3 in 4-stage random access) that includes RRC connection request information such as a terminal ID. The Data generation unit 106 encodes and modulates the generated data signal and outputs the modulated signal (data sequence) as a Data part signal to the Data resource allocation unit 107.

[0052] The Data resource allocation unit 107 assigns the Data part signals input from the Data generation unit 106 to frequency resources corresponding to the cluster number and interlace number indicated in the transmission resource information input from the Data resource setting unit 103. The Data resource allocation unit 107 also outputs the Data part signals to the wireless transmission unit 108 based on the transmission timing indicated in the transmission resource information input from the Data resource setting unit 103.

[0053] The wireless transmission unit 108 performs transmission processing such as D / A conversion and upconversion on the Preamble part signal input from the Preamble resource allocation unit 105 and the Data part signal input from the Data resource allocation unit 107, and transmits the resulting wireless signal (for example, MSG1 in two-stage random access (see Figure 1(b))) from the antenna 109 to the base station 200.

[0054] The wireless receiver 110 performs reception processing such as down-conversion and A / D conversion on the received signal received from the base station 200 via the antenna 109, and outputs the received signal obtained from the reception processing to the demodulation / decoding unit 111. The received signal received from the base station 200 includes, for example, the response data signal of PRACH in two-stage random access (for example, MSG2 shown in Figure 1(b)).

[0055] The demodulation / decoding unit 111 demodulates and decodes the received signal input from the wireless receiver unit 110. If the demodulation / decoding unit 111 successfully receives the PRACH response data signal, the two-stage random access RRC connection process is completed.

[0056] [Base station configuration] Figure 6 is a block diagram showing the configuration of the base station 200 according to this embodiment.

[0057] In Figure 6, the base station 200 includes an antenna 201, a wireless receiving unit 202, a control unit 203, a preamble detection unit 206, a demodulation / decoding unit 207, a scheduling unit 208, a data generation unit 209, an encoding / modulation unit 210, and a wireless transmission unit 211.

[0058] The wireless receiver 202 performs reception processing such as down-conversion and A / D conversion on the RACH signal (e.g., MSG1 in two-stage random access) received from the terminal 100 via the antenna 201 using the PRACH transmission resources available within the cell of the base station 200, and outputs the signal obtained from the reception processing to the preamble detection unit 206 and the demodulation / decoding unit 207.

[0059] The control unit 203 determines, for example, the wireless resources to which each terminal 100 will assign PRACH (for example, the allocation resources for the Preamble part and Data part included in MSG1 in two-stage random access). The method for setting PRACH transmission resources in the control unit 203 is the same as the method for setting PRACH transmission resources in terminal 100 (control unit 101). For example, the control unit 203 includes a Preamble resource setting unit 204 and a Data resource setting unit 205.

[0060] The Preamble resource setting unit 204 outputs, for example, the available Preamble numbers within the cell of the base station 200 to the Data resource setting unit 205 and the Preamble detection unit 206.

[0061] The Data resource setting unit 205 sets the transmission resources for the Data part based on the Preamble number input from the Preamble resource setting unit 204. The Data resource setting unit 205 outputs information indicating the set transmission resources to the demodulation / decoding unit 207. Details of how the Data resource setting unit 205 derives the transmission resources for the Data part will be described later.

[0062] The Preamble detection unit 206 generates a replica signal for detecting a PRACH preamble (e.g., a CS-ZC sequence) using the sequence number and CS number corresponding to the Preamble number input from the Preamble resource setting unit 204. The Preamble detection unit 206 performs correlation processing between the generated replica signal and the signal input from the wireless receiver unit 202 to detect the PRACH preamble and estimate its timing. The Preamble detection unit 206 outputs the detection result and the estimation result to the scheduling unit 208.

[0063] 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).

[0064] The demodulation and decoding unit 207 performs demodulation and decoding on the received data (Data part signal) included in the transmission resource indicated in the transmission resource information input from the Data resource setting unit 205, which is among the received signals input from the wireless receiver unit 202, and outputs the decoding result to the scheduling unit 208.

[0065] The scheduling unit 208 sets up an RRC connection with terminal 100 based on timing information of terminal 100 input from the preamble detection unit 206, or terminal ID information included in the data part signal input from the demodulation / decoding unit 207. The scheduling unit 208 sets up data transmission resources, for example, on the terminal 100 side, including control information for the RRC connection or control information for contention resolution, and outputs the data transmission resource information to the data generation unit 209.

[0066] In the base station 200, for example, the control unit 203, the preamble detection unit 206, and the demodulation / decoding unit 207 attempt to detect the preamble part and demodulate and decode the data part signal for each of the preamble numbers available within the cell of the base station 200. Meanwhile, the scheduling unit 208 performs RRC connection processing for terminals 100 whose data part signal decoding result is OK (no errors).

[0067] The data generation unit 209 uses the wireless resources indicated in the data transmission resource information input from the scheduling unit 208 to generate data including control information for RRC connection on the terminal side or control information for contention resolution, and outputs the generated data signal (for example, equivalent to MSG2 of two-stage random access) to the encoding and modulation unit 210.

[0068] The encoding and modulation unit 210 modulates and encodes the data signal input from the data generation unit 209, and outputs the modulated signal to the wireless transmission unit 211.

[0069] The wireless transmission unit 211 performs transmission processing such as D / A conversion, upconversion, and amplification on the signal input from the encoding and modulation unit 210, and transmits the resulting wireless signal (for example, MSG2 in two-stage random access (see, for example, Figure 1(b))) from the antenna 201 to the terminal 100.

[0070] [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.

[0071] Figure 7 is a sequence diagram showing an example of operation for terminal 100 (Figure 5) and base station 200 (Figure 6).

[0072] In Figure 7, the base station 200 notifies (in other words, broadcasts) the terminal 100 of cell information, including PRACH transmission resource information available within the cell (ST101).

[0073] Terminal 100 determines the transmission resource for the Preamble part signal included in the PRACH that terminal 100 transmits, based on the PRACH transmission resource information shown in the cell information (ST102).

[0074] Terminal 100 determines the transmission resource for the Data part signal based on the transmission resource for the determined Preamble part signal (ST103).

[0075] Terminal 100 uses the determined transmission resources to transmit a PRACH signal (e.g., MSG1 in two-stage random access) including the Preamble part signal and the Data part signal to base station 200 (ST104).

[0076] The base station 200 detects the preamble part signal and decodes the data part signal (ST105). If the decoding of the data part signal is successful, the base station 200 sets up an RRC connection between the corresponding terminal 100 and the base station 200, and determines (schedules) the transmission resources for a response signal (e.g., MSG2 in two-stage random access) that includes control information for the RRC connection on the terminal side or control information for contention resolution (ST106). The base station 200 transmits a data signal including the response signal to the terminal 100 (ST107).

[0077] Terminal 100 decodes the data signal. If it decodes the data signal without error and does not detect any collisions with other terminals' RACHs, it terminates the RRC connection process with base station 200 using two-stage random access (ST108). If the data signal decoding is incorrect or if a collision with another terminal's RACH is detected, terminal 100 restarts the random access process from, for example, ST102.

[0078] [How to configure the data part's transmission resources] Next, an example of how to configure the transmission resources for the Data part in the Data resource setting unit 103 of terminal 100 and the Data resource setting unit 205 of base station 200 will be described.

[0079] In this embodiment, when applying a Block-based interlace design to the Preamble part in two-stage random access, the transmission resources of the Data part are set (in other words, derived) based on the transmission resources of the Preamble part.

[0080] For example, terminal 100 and base station 200 derive frequency and time resources for the data part based on at least the Preamble number and Interlace number of the Preamble part. In other words, when a block-based interlace design is applied to the Preamble part in two-stage random access, the data parts of multiple terminals are separated and multiplexed by frequency resources or time resources.

[0081] For example, as will be described later, the transmission resources of the Data part (e.g., cluster number, interlace number, or transmission symbol position) corresponding to each of the multiple Preamble numbers are associated with each other in such a way that they are all different.

[0082] As a result, the preamble parts of multiple terminals 100 are code-multiplexed on the same interlace, and the data parts of multiple terminals 100 are frequency-multiplexed or time-multiplexed.

[0083] Furthermore, PRACH can be easily frequency multiplexed with other uplink channels by using a different interlace number than other uplink channels that apply a block-based interlace design (e.g., PUSCH (Physical Uplink Shared Channel), PUCCH (Physical Uplink Control Channel), SRS (Sounding Reference Signal), etc.).

[0084] Furthermore, since the terminal 100 and base station 200 derive the transmission resources for the Data part from a predetermined correspondence with the Preamble part, the signaling required to instruct the transmission resources for the Data part can be reduced.

[0085] Furthermore, the correspondence between the transmission resources of the Preamble part (e.g., Preamble number) and the transmission resources of the Data part may be predefined in the specification. This eliminates the need for new signaling for the introduction of two-stage random access. Alternatively, the correspondence between the transmission resources of the Preamble part and the Data part may be reported as cell information. In this case, the correspondence may be updated quasi-statically depending on the communication environment within the cell.

[0086] In addition to the derivation process described below, the transmission resources for the Data part may also be derived using information notified from the base station 200 to the terminal 100.

[0087] The following explains each of the derivation examples 1 to 7 for the Data part's transmission resources.

[0088] [Derivation Example 1] Figure 8 shows an example of the correspondence between the transmission resources of the Preamble part and the Data part related to Derivation Example 1.

[0089] In Figure 8, as an example, the transmission resources of the Preamble part are configured with one interlace (e.g., interlace number 0) within each of the 10 clusters (e.g., cluster numbers 0 to 9). In other words, the transmission resources of the Preamble part are distributed across multiple bandwidths (e.g., clusters #0 to #9). Also in Figure 8, as an example, terminal 100 is configured with five Preamble numbers 0 to 4. Each Preamble number is associated with a different code sequence (e.g., CS-ZC sequence). For example, terminal 100 randomly selects one Preamble number from Preamble numbers 0 to 4.

[0090] Furthermore, in derivation example 1, as shown in Figure 8, the transmission resource of the Data part is set to the interlace set in the Preamble part (interlace number 0 in Figure 8). Note that the interlace number set in the transmission resource of the Data part may be different from the interlace number of the Preamble part.

[0091] Furthermore, in derivation example 1, as shown in Figure 8, the transmission resources of the Data part are located in some of the clusters among the multiple clusters set for the transmission resources of the Preamble. In other words, the transmission resources of the Data part are limited to some of the clusters (or cluster numbers) set for the Preamble part. Also, as shown in Figure 8, the aforementioned clusters set for the transmission resources of the Data part are associated with the Preamble number (in other words, the code sequence) set for the Preamble part. For example, as shown in Figure 8, each Preamble number is associated with a different cluster number as a transmission resource of the Data part. In Figure 8, as an example, the clusters associated with each Preamble number are separated by 5 clusters.

[0092] Figure 9 shows an example of setting transmission resources for terminal 100 in derivation example 1.

[0093] In Figure 9, the horizontal axis represents the frequency domain (or frequency resource allocation). For example, in Figure 9, the interlace bandwidth is 1 PRB, the cluster bandwidth is 5 PRB (in other words, 5 interlaces), the interlace numbers are 0 to 4, and the cluster numbers are #0, #1, #2, ... Also, in Figure 9, the vertical axis represents the time domain (e.g., time resource allocation). For example, in Figure 9, there are 2 symbols (in the case of OFDM (Orthogonal Frequency Division Multiplexing), OFDM symbols including CP (Cyclic Prefix)). Note that the symbol lengths of the Preamble part and the Data part may be different.

[0094] Furthermore, Figure 9 shows an example where terminal A (UE#A) selects Preamble number 0 as shown in Figure 8, and terminal B (UE#B) selects Preamble number 1 as shown in Figure 8.

[0095] As shown in Figure 9, each Preamble part of terminal A and terminal B is assigned to the frequency band of interlace number 0 of each cluster. In this frequency band, each Preamble part of terminal A and terminal B uses different CS-ZC sequences associated with Preamble number 0 and Preamble number 1, respectively. Therefore, each Preamble part of terminal A and terminal B is code-multiplexed in the same interlace and can be separated at base station 200.

[0096] Furthermore, as shown in Figure 9, the Data part of terminal A is assigned to the same frequency band with interlace number 0 as the Preamble part in clusters 0 and 5. Similarly, as shown in Figure 9, the Data part of terminal B is assigned to the same frequency band with interlace number 0 as the Preamble part in clusters 1 and 6.

[0097] Thus, different clusters (or cluster numbers) are used for the transmission resources of each Data part of terminal A and terminal B. Therefore, the Data parts of terminals A and B, which have different Preamble numbers, are frequency multiplexed onto orthogonal frequency resources and can be separated at base station 200.

[0098] Therefore, in derivation example 1, Data part signals transmitted from multiple terminals 100 can be frequency multiplexed without any new signaling regarding the Data part transmission resources.

[0099] Here, for example, there is a provision for temporary operation defined for OFDMA (Orthogonal Frequency Division Multiple Access) signals in IEEE 802.11ax (for example, the provision that "within the same COT (Channel Occupancy Time), if some signals satisfy the 80-100% OCB requirement, the bandwidth of some signals only needs to be 2 MHz or more"). In contrast, in derivation example 1, for example, as shown in Figure 8, the Preamble part signal satisfies the 80-100% OCB requirement, so the bandwidth of the Data part signal only needs to be, for example, 2 MHz or more.

[0100] Furthermore, in the example shown in Figure 8, the Data part signal from each terminal 100 is assigned to a cluster with a relatively distant cluster number (cluster interval: 5 in Figure 8). This allows terminal 100 to transmit the Data part signal over a wide bandwidth, thereby obtaining frequency diversity gain and improving the reception performance of the Data part signal.

[0101] Note that the transmission resources for the Data part are not limited to the example shown in Figure 8. For example, in the case of TDD (Time Division Duplexing), if terminal 100 can estimate the uplink reception quality and identify a cluster with good quality, the Data part signal may be assigned to a cluster with a relatively close cluster number, as shown in Figure 10. For example, in Figure 10, the cluster numbers associated with each Preamble number are consecutive numbers. This allows terminal 100 to select a cluster (in other words, a Preamble number) where good quality can be expected and transmit the Data part signal, thereby improving the reception performance of the Data part signal.

[0102] Note that the transmission resources (e.g., cluster numbers) for the Data part shown in Figures 8 and 10 are examples only, and the cluster numbers associated with each Preamble number for the Data part are not limited to these.

[0103] [Derivation Example 2] Figure 11 shows an example of the correspondence between the transmission resources of the Preamble part and the Data part related to derivation example 2.

[0104] In Figure 11, the transmission resources of the Preamble part are the same as in Derivation Example 1 (see, for example, Figure 8 or Figure 9).

[0105] In derivation example 2, as shown in Figure 11, the transmission resource of the Data part is set to the interlace set in the Preamble part (interlace number 0 in Figure 11), similar to derivation example 1. Note that the interlace number set in the transmission resource of the Data part may be different from the interlace number of the Preamble part.

[0106] Furthermore, in Derivation Example 2, similar to Derivation Example 1, the Data part's transmission resources are located in some of the clusters among the multiple clusters set for the Preamble's transmission resources in the frequency domain. In Derivation Example 2, as shown in Figure 11, the Data part's transmission resources are located in three symbols (Sym#0, Sym#1, and Sym#2) in the time domain.

[0107] In derivation example 2, as shown in Figure 11, some of the clusters set as the transmission resources of the Data part are associated with the Preamble numbers (in other words, code sequences) set for the Preamble part. In this case, some of the clusters set as the transmission resources of the Data part are different for each of the multiple symbols (Sym#0, Sym#1, and Sym#2 in Figure 11). For example, as shown in Figure 11, each Preamble number is associated with a different cluster number for each symbol as a transmission resource of the Data part.

[0108] Figure 12 shows an example of setting transmission resources for terminal 100 in derivation example 2.

[0109] In Figure 12, the horizontal axis represents the frequency domain (or frequency resource allocation), and the vertical axis represents the time domain (e.g., time resource allocation). The cluster and interlacing configuration within the cluster shown in Figure 12 are the same as in Derivation Example 1 (e.g., Figure 9). However, in Figure 12, one symbol is set for the Preamble part and three symbols are set for the Data part in the time domain.

[0110] Furthermore, Figure 12 shows an example where terminal A (UE#A) selects Preamble number 0 as shown in Figure 11, and terminal B (UE#B) selects Preamble number 1 as shown in Figure 11.

[0111] As shown in Figure 12, each Preamble part of terminals A and B is assigned to the frequency band of interlace number 0 of each cluster, similar to Figure 9, and uses different CS-ZC sequences associated with Preamble number 0 and Preamble number 1, respectively.

[0112] Furthermore, as shown in Figure 12, the Data part of terminal A is assigned to the same interlace number 0 frequency band as the Preamble part in clusters 0 and 5 for symbol 0 (Sym#0), to the same interlace number 0 frequency band as the Preamble part in clusters 2 and 7 (cluster number 6 is not shown) for symbol 1 (Sym#1), and to the same interlace number 0 frequency band as the Preamble part in clusters 4 and 9 (cluster number 9 is not shown) for symbol 2 (Sym#2).

[0113] Similarly, as shown in Figure 12, the Data part of terminal B is assigned to the same interlace number 0 frequency band as the Preamble part in clusters 1 and 6 for symbol 0 (Sym#0), to the same interlace number 0 frequency band as the Preamble part in clusters 3 and 8 (cluster 8 is not shown) for symbol 1 (Sym#1), and to the same interlace number 0 frequency band as the Preamble part in clusters 0 and 5 for symbol 2 (Sym#2).

[0114] Thus, the transmission resources for each Data part of terminal A and terminal B use different clusters (or cluster numbers) for each symbol. Therefore, the Data parts of terminals A and B, which have different Preamble numbers, are frequency multiplexed onto orthogonal frequency resources for each symbol, and can be separated at base station 200.

[0115] Furthermore, in derivation example 2, the Data part signal of each terminal 100 is frequency-hopped between multiple symbols, so the reception performance of the Data part signal can be improved by frequency diversity gain.

[0116] In Figure 12, an example is shown where the Data part signal of each terminal 100 is frequency-hopped between multiple symbols. However, the Data part signal of each terminal 100 may be assigned to the same frequency band across multiple symbols.

[0117] [Derivation Example 3] Figure 13 shows an example of the correspondence between the transmission resources of the Preamble part and the Data part related to Derivation Example 3.

[0118] In Figure 13, the transmission resources of the Preamble part are the same as in Derivation Example 1 (see, for example, Figure 8 or Figure 9). However, in Figure 13, as an example, ten Preamble numbers 0 to 9 are set for terminal 100. Each Preamble number is associated with a different code sequence (e.g., CS-ZC sequence). For example, terminal 100 randomly selects one Preamble number from Preamble numbers 0 to 9.

[0119] Furthermore, in Derivation Example 3, as shown in Figure 13, the transmission resources of the Data part are configured with the interlace (interlace number 0 in Figure 13) and some of the clusters (or cluster numbers) configured in the Preamble part, similar to Derivation Example 1 (see, for example, Figure 8 or Figure 9).

[0120] Furthermore, in derivation example 3, the transmission resource for the Data part is configured with at least one sub-PRB included in the configured cluster.

[0121] Here, a sub-PRB is a resource unit obtained by dividing, for example, one PRB (12 subcarriers in LTE or NR) into units of one or more subcarriers (e.g., 4 subcarriers or 6 subcarriers). In other words, a sub-PRB is a resource unit contained within each interlace of multiple clusters in the transmission resource of the Preamble part. Note that the number of subcarriers constituting one PRB (or one interlace within each cluster) is not limited to 12 subcarriers, and the number of subcarriers constituting a sub-PRB (in other words, the number of divisions for one PRB) is not limited to 4 or 6 subcarriers. The sub-PRB shown in Figure 13 is a resource unit obtained by dividing one PRB into two.

[0122] For example, as shown in Figure 13, the Data part's transmission resource includes at least one sub-PRB of multiple sub-PRBs located in the cluster where the Preamble part's transmission resource is located.

[0123] The at least one sub-PRB configured in the Data part's transmission resource is associated with the Preamble number (in other words, the code sequence) configured in the Preamble part. In this case, different sub-PRB numbers are associated with multiple Preamble numbers that share the same cluster number in the Data part's transmission resource. For example, in Figure 13, sub-PRB numbers 0 (sub-PRB#0) and 1 (sub-PRB#1) are associated with the pair of Preamble numbers 0 and 1, respectively. The same applies to other pairs of Preamble numbers that share the same cluster number.

[0124] In other words, each Preamble number shown in Figure 13 is associated with a resource that differs in at least one of its cluster number and sub-PRB number as a data part transmission resource.

[0125] Figure 14 shows an example of setting transmission resources for terminal 100 in derivation example 3.

[0126] In Figure 14, the horizontal axis represents the frequency domain (or frequency resource allocation), and the vertical axis represents the time domain (e.g., time resource allocation). The cluster and interlacing configuration within the cluster shown in Figure 14 are the same as in Derivation Example 1 (e.g., Figure 9). However, in Figure 14, each PRB (e.g., 12 subcarriers #0 to #11) constitutes sub-PRB#0 (e.g., subcarriers #0 to #5) and sub-PRB#1 (e.g., subcarriers #6 to #11).

[0127] Furthermore, Figure 14 shows an example where terminal A (UE#A) selects Preamble number 0 as shown in Figure 13, and terminal B (UE#B) selects Preamble number 1 as shown in Figure 13.

[0128] As shown in Figure 14, each Preamble part of terminals A and B is assigned to the frequency band of interlace number 0 of each cluster, similar to Figure 9, and uses different CS-ZC sequences associated with Preamble number 0 and Preamble number 1, respectively.

[0129] Furthermore, as shown in Figure 14, the Data part of terminal A is assigned to sub-PRB#0, which has the same interlace number 0 as the Preamble part in clusters 0 and 5. Similarly, as shown in Figure 14, the Data part of terminal B is assigned to sub-PRB#1, which has the same interlace number 0 as the Preamble part in clusters 0 and 5.

[0130] Thus, the transmission resources for each Data part of terminal A and terminal B use frequency resources with at least one different cluster number and sub-PRB number. Therefore, the Data parts of terminals A and B, which have different Preamble numbers, are frequency multiplexed, for example, to orthogonal frequency resources in interlaced data of the same number, and can be separated at base station 200.

[0131] Furthermore, in derivation example 3, as shown in Figure 14, it becomes possible to assign data part signals from different terminals 100 in sub-PRB units to the same interlace within the same cluster. Thus, according to derivation example 3, by assigning data part signals in sub-PRB units, the number of PRACHs that can be assigned in the same interlace can be increased, and the collision rate of random access can be reduced.

[0132] [Derivation Example 4] Figure 15 shows an example of the correspondence between the transmission resources of the Preamble part and the Data part related to derivation example 4.

[0133] In Figure 15, the transmission resources of the Preamble part are the same as in Derivation Example 1 (see, for example, Figure 8 or Figure 9).

[0134] In derivation example 4, each of the multiple clusters to which the Preamble part and Data part are assigned consists of multiple subcarriers (for example, also called Combs or Tones).

[0135] For example, in the transmission resource of the Preamble part, each resource unit (in other words, the interlace unit within the cluster) of multiple clusters is assigned a number (e.g., subcarrier number, Com number, or Tone number) to each of the multiple subcarriers. For example, in Figure 15, each interlace within the cluster contains five subcarriers (Comb numbers 0-4).

[0136] In derivation example 4, as shown in Figure 15, the transmission resource of the Data part is configured with frequency resources on a subcarrier basis. For example, the transmission resource of the Data part includes subcarriers of the same Comb number within multiple clusters. The Comb numbers included in the transmission resource of the Data part are associated with the Preamble numbers (in other words, code sequences) configured for the Preamble part.

[0137] For example, in Figure 15, each Preamble number 0-4 is associated with a different Comb number 0-4. In other words, the transmission resources of the Data part are subject to subcarrier-level interlacing (for example, called tone-interlace design or IFDMA (Interleaved Frequency Division Multiple Access)).

[0138] Figure 16 shows an example of setting transmission resources for terminal 100 in derivation example 4.

[0139] In Figure 16, the horizontal axis represents the frequency domain (or frequency resource allocation), and the vertical axis represents the time domain (e.g., time resource allocation). Furthermore, the cluster and interlacing configuration within the cluster in the symbol to which the Preamble part shown in Figure 16 is allocated is the same as in Derivation Example 1 (e.g., Figure 9).

[0140] On the other hand, in Figure 16, in the symbol to which the Data part is assigned, each PRB contains five Comb#0 to #4 (subcarriers or subcarrier groups). Note that the number of Combs constituting a PRB is not limited to five; other numbers are also acceptable.

[0141] Furthermore, Figure 16 shows an example where terminal A (UE#A) selects Preamble number 0 as shown in Figure 15, and terminal B (UE#B) selects Preamble number 1 as shown in Figure 15.

[0142] As shown in Figure 16, each Preamble part of terminals A and B is assigned to the frequency band of interlace number 0 of each cluster, similar to Figure 9, and uses different CS-ZC sequences associated with Preamble number 0 and Preamble number 1, respectively.

[0143] Furthermore, as shown in Figure 16, the Data part of terminal A is assigned to the Comb (or subcarrier) with Comb number 0 for each of the interlaces #0 to #4 of each cluster. Similarly, as shown in Figure 16, the Data part of terminal B is assigned to the Comb (or subcarrier) with Comb number 1 for each of the interlaces #0 to #4 of each cluster.

[0144] In this way, the data parts of terminals A and B, which have different preamble numbers, are frequency multiplexed onto orthogonal frequency resources and can be separated at base station 200.

[0145] Furthermore, in derivation example 4, the Data part signal of each terminal 100 is assigned to multiple interlaces within each cluster. In other words, the Data part signal of each terminal 100 is assigned to each cluster to which the Preamble part signal is assigned. Therefore, the Data part signal of each terminal 100 is assigned across the same bandwidth as the Preamble part signal (clusters #0 to #9 in Figure 16).

[0146] Here, regarding signal transmission in the unlicensed band, the ETSI (European Telecommunications Standards Institute) has established a regulation called the "OCB regulation" which states that signals should be transmitted in 80-100% of the carrier sense band (also called a subband, which is a bandwidth that is an integer multiple of 20 MHz).

[0147] In derivation example 4, for example, as shown in Figure 16, both the Preamble part and the Data part are transmitted using clusters numbered 0 to 9, so the 80-100% OCB requirement can be satisfied.

[0148] [Derivation Example 5] Figure 17 shows an example of the correspondence between the transmission resources of the Preamble part and the Data part related to derivation example 5.

[0149] In Figure 17, the transmission resources of the Preamble part are the same as in Derivation Example 1 (see, for example, Figure 8 or Figure 9). However, in Figure 17, as an example, ten Preamble numbers 0 to 9 are set for terminal 100. Each Preamble number is associated with a different code sequence (e.g., CS-ZC sequence). For example, terminal 100 randomly selects one Preamble number from Preamble numbers 0 to 9.

[0150] Furthermore, in derivation example 5, as shown in Figure 17, the transmission resources of the Data part are configured in the frequency domain with the interlace (interlace number 0 in Figure 17) and some of the clusters (or cluster numbers) configured in the Preamble part, similar to derivation example 1 (see, for example, Figure 8 or Figure 9).

[0151] Furthermore, in derivation example 5, the transmission resource of the Data part is configured with at least one symbol from among multiple symbols (two symbols in Figure 17) in the time domain.

[0152] The at least one symbol set in the Data part's transmission resource is associated with the Preamble number (in other words, the code sequence) set in the Preamble part. In this case, as shown in Figure 17, different symbol numbers (symbol numbers 0 and 1) are associated with multiple Preamble numbers that have the same cluster number set in the Data part's transmission resource. For example, in Figure 17, symbol numbers 0 and 1 are associated with the pair of Preamble numbers 0 and 1, respectively. The same applies to other pairs of Preamble numbers that have the same cluster number associated with them. In other words, each Preamble number shown in Figure 17 is associated with a resource as a Data part's transmission resource that has at least one different cluster number and symbol number.

[0153] Figure 18 shows an example of setting transmission resources for terminal 100 in derivation example 5.

[0154] In Figure 18, the horizontal axis represents the frequency domain (or frequency resource allocation), and the vertical axis represents the time domain (e.g., time resource allocation). The cluster and interlacing configuration within the cluster shown in Figure 18 are the same as in Derivation Example 1 (e.g., Figure 9). However, in Figure 18, in the time domain, one symbol is set for the Preamble part, and multiple symbols (two symbols in Figure 18) are set for the Data part.

[0155] Furthermore, Figure 18 shows an example where terminal A (UE#A) selects Preamble number 0 as shown in Figure 17, and terminal B (UE#B) selects Preamble number 1 as shown in Figure 17.

[0156] As shown in Figure 18, each Preamble part of terminals A and B is assigned to the frequency band of interlace number 0 of each cluster, similar to Figure 9, and uses different CS-ZC sequences associated with Preamble number 0 and Preamble number 1, respectively.

[0157] Furthermore, as shown in Figure 18, the Data part of terminal A is assigned to the symbol (Sym#0) with the same interlace number 0 and symbol number 0 as the Preamble part in clusters 0 and 5. Similarly, as shown in Figure 18, the Data part of terminal B is assigned to the symbol (Sym#1) with the same interlace number 0 and symbol number 1 as the Preamble part in clusters 0 and 5.

[0158] Thus, the transmission resources used for each Data part of terminal A and terminal B are resources with at least one different cluster number and symbol number. Therefore, the Data parts of terminals A and B, which have different Preamble numbers, are time-multiplexed, for example, into symbols, which are orthogonal time resources in interlaced data of the same number, and can be separated at base station 200.

[0159] Furthermore, in derivation example 5, for example, compared to derivation example 1, the number of PRACHs that can be allocated in the same interlace can be increased by increasing the time resources (e.g., number of symbols) for transmitting the Data part signal, thereby reducing the collision rate of random access.

[0160] [Derivation Example 6] Figure 19 shows an example of the correspondence between the transmission resources of the Preamble part and the Data part related to derivation example 6.

[0161] In Figure 19, the transmission resources of the Preamble part are the same as in Derivation Example 1 (see, for example, Figure 8 or Figure 9). However, in Figure 19, as an example, four Preamble numbers 0 to 3 are set for terminal 100. Each Preamble number is associated with a different code sequence (e.g., CS-ZC sequence). For example, terminal 100 randomly selects one Preamble number from Preamble numbers 0 to 3.

[0162] Furthermore, in derivation example 6, the Preamble part and the Data part are frequency-multiplexed into different interlaces within the same symbol.

[0163] For example, as shown in Figure 19, the transmission resource of the Data part is configured with a different interlace (or interlace number) than the interlace configured in the Preamble part (interlace number 0 in Figure 19) for each cluster configured in the Preamble part. The interlace on which the transmission resource of the Data part is configured is associated with the Preamble number (in other words, the code sequence) configured for the Preamble part. In this case, the Data part of terminal 100 using a different Preamble number is frequency multiplexed into different interlaces within the same symbol.

[0164] Furthermore, as shown in Figure 19, the transmission resource for the Data part is set to the same cluster (or cluster number) as the cluster set in the Preamble part (cluster numbers 0-9 in Figure 19).

[0165] Figure 20 shows an example of setting transmission resources for terminal 100 in derivation example 6.

[0166] In Figure 20, the horizontal axis represents the frequency domain (or frequency resource allocation), and the vertical axis represents the time domain (e.g., time resource allocation). Furthermore, the cluster and interlacing configuration within the cluster shown in Figure 20 is the same as in Derivation Example 1 (e.g., Figure 9). However, in Figure 20, one symbol is assigned to both the Preamble part and the Data part in the time domain.

[0167] Furthermore, Figure 20 shows an example where terminal A (UE#A) selects Preamble number 0 as shown in Figure 19, and terminal B (UE#B) selects Preamble number 1 as shown in Figure 19.

[0168] As shown in Figure 20, each Preamble part of terminals A and B is assigned to the frequency band of interlace number 0 of each cluster, similar to Figure 9, and uses different CS-ZC sequences associated with Preamble number 0 and Preamble number 1, respectively.

[0169] Furthermore, as shown in Figure 20, the Data part of terminal A is assigned to the frequency band of interlace number 1 for each cluster. Also, as shown in Figure 20, the Data part of terminal B is assigned to the frequency band of interlace number 2 for each cluster.

[0170] In this way, the Preamble parts of terminals A and B, and the Data parts of terminals A and B with different Preamble numbers, are frequency multiplexed onto orthogonal frequency resources and can be separated at base station 200. In other words, multiple terminals 100 can transmit Preamble parts and Data parts using the same symbol.

[0171] Therefore, according to derivation example 6, the delay time required for random access can be reduced by frequency multiplexing the Preamble part and the Data part.

[0172] Furthermore, in derivation example 6, as shown in Figure 20, for example, both the Preamble part and the Data part are transmitted using clusters numbered 0 to 9, so, similar to derivation example 4, the 80-100% OCB requirement can be satisfied.

[0173] [Derivation Example 7] Figure 21 shows an example of the correspondence between the transmission resources of the Preamble part and the Data part related to derivation example 7.

[0174] In Figure 21, the transmission resources of the Preamble part are the same as in Derivation Example 1 (see, for example, Figure 8 or Figure 9). However, in Figure 21, as an example, four Preamble numbers 0 to 3 are set for terminal 100. Each Preamble number is associated with a different code sequence (e.g., CS-ZC sequence). For example, terminal 100 randomly selects one Preamble number from Preamble numbers 0 to 3.

[0175] Furthermore, in Derivation Example 7, similar to Derivation Example 1, the Data part's transmission resources are placed in some of the clusters among the multiple clusters configured for the Preamble's transmission resources. For example, as shown in Figure 21, each Preamble number is associated with clusters of different cluster numbers for the Data part's transmission resources.

[0176] Furthermore, in derivation example 7, as shown in Figure 21, the number of clusters for the transmission resources of the Data part associated with the Preamble number differs for each Preamble (in other words, for each code sequence used in the Preamble part signal). For example, as shown in Figure 21, three clusters (or cluster numbers) are associated with Preamble numbers 0 and 1, respectively, while two clusters (or cluster numbers) are associated with Preamble numbers 2 and 3, respectively.

[0177] For example, a Preamble number that terminal 100 can select may be set according to the reception quality of terminal 100. The reception quality of terminal 100 may be, for example, the path loss level between terminal 100 (UE) and base station 200 (gNB), or the received signal level (e.g., RSRP (Received Signal Reception Power)), or other parameters.

[0178] In Figure 21, terminal 100 may, for example, allow selection of Preamble numbers 0 and 1 when the path loss level is greater than threshold X, and allow selection of Preamble numbers 2 and 3 when the path loss level is less than or equal to threshold X. Note that Figure 21 is just an example, and the number of clusters associated with a Preamble number in the Data part's transmission resources is not limited to 2 or 3, and the types of clusters associated with a Preamble number are not limited to 2, but may be 3 or more.

[0179] Figure 22 shows an example of setting transmission resources for terminal 100 in derivation example 7.

[0180] In Figure 22, the horizontal axis represents the frequency domain (or frequency resource allocation), and the vertical axis represents the time domain (e.g., time resource allocation). Furthermore, the cluster and interlacing configuration within the cluster shown in Figure 22 are the same as in Figure 9.

[0181] Furthermore, Figure 22 shows an example where terminal A (UE#A) has a path loss level greater than threshold X and randomly selects Preamble number 0 as shown in Figure 21, and terminal B (UE#B) has a path loss level less than or equal to threshold X and randomly selects Preamble number 2 as shown in Figure 21.

[0182] As shown in Figure 22, each Preamble part of terminals A and B is assigned to the frequency band of interlace number 0 of each cluster, similar to Figure 9, and uses different CS-ZC sequences associated with Preamble number 0 and Preamble number 1, respectively.

[0183] Furthermore, as shown in Figure 22, the Data part of terminal A is assigned to sub-PRB#0 with the same interlace number 0 as the Preamble part in the three clusters with cluster numbers 0, 3, and 5. Also, as shown in Figure 22, the Data part of terminal B is assigned to sub-PRB#1 with the same interlace number 0 as the Preamble part in the two clusters with cluster numbers 2 and 7.

[0184] In this way, the data parts of terminals A and B, which have different preamble numbers, are frequency multiplexed onto orthogonal frequency resources and can be separated at base station 200.

[0185] For example, the amount of data transmitted in the Data part is constant. Therefore, as the number of clusters used for transmitting the Data part increases, the coding rate of the Data part decreases, and performance improves. Thus, for example, as shown in Figure 22, terminal A, whose path loss level is greater than the threshold X, can improve the performance of the Data part by using more clusters to transmit the Data part compared to terminal B, whose path loss level is less than or equal to the threshold X.

[0186] Therefore, according to derivation example 7, the performance of the Data part can be improved by appropriately changing the amount of frequency resources or the coding rate for transmitting the Data part signal according to the reception quality of terminal 100 (e.g., path loss level).

[0187] The above explains the derivation examples 1-7 of the Data part's transmission resources.

[0188] Furthermore, at least two of the above-mentioned derivation examples 1 to 7 may be combined. For example, by combining derivation example 2 and derivation example 3, a frequency diversity effect can be obtained for the data part, the number of PRACHs that can be allocated in the same interlace can be increased, and the collision rate of random access can be reduced.

[0189] Alternatively, the terminal 100 and the base station 200 may, for example, switch between at least two of the derivation examples 1 to 7 depending on the settings of the terminal 100 (or the status of the terminal 100).

[0190] As described above, in this embodiment, the resources used for transmitting the Data part are determined based on the resources used for transmitting the Preamble part. For example, for each Preamble number that can be selected by terminal 100, the transmission resources for the Preamble part (e.g., cluster number and interlace number) are associated with the transmission resources for the Data part (e.g., cluster number, interlace number, sub-PRB number, comb number, or symbol number, etc.).

[0191] This allows terminal 100 and base station 200 to identify transmission resources for both the Preamble part and the Data part according to the configured Preamble number. Furthermore, the Preamble part transmitted from multiple terminals 100 is code multiplexed, and the Data part transmitted from multiple terminals 100 is frequency multiplexed or time multiplexed.

[0192] Therefore, according to this embodiment, random access processing can be performed appropriately.

[0193] The embodiments of this disclosure have been described above.

[0194] (Other embodiments) (1) The above embodiments described operation in the unlicensed bandwidth. However, this disclosure is not limited to the unlicensed bandwidth but can also be applied to the licensed bandwidth and similar effects can be obtained. For example, this disclosure can also be applied to grant-free transmissions or URLLC service transmissions in the licensed bandwidth where the transmission resources are predetermined, and the effects of reducing latency or improving performance can be obtained.

[0195] (2) In the above embodiment, the correspondence between the Preamble number and the transmission resources of the Preamble part and Data part was defined, for example, in the tables shown in Figures 8, 10, 11, 13, 15, 17, 19 and 21, but is not limited to this, and may be defined by formula, for example.

[0196] As an example, in derivation example 2 (see, for example, Figure 11), the cluster numbers (represented as C0, C1, and C2) for each symbol (symbol number) among the transmission resources of the Data part are expressed by the following formula. C0 = P, P + N / 2 C1 = P + 2 , mod(P + 2 +N / 2, N) C2 = P + 4 , mod(P + 4 +N / 2, N) however, C0: The cluster number used for symbol number 0 in the Data part (any number from 0 to N-1) C1: The cluster number used for symbol number 1 in the Datapart (any number from 0 to N-1) C2: The cluster number used for symbol number 2 in the Data part (any number from 0 to N-1) P: Preamble number (for example, 0-4 in Figure 11) N: Number of clusters (for example, N=10 in Figure 11)

[0197] (3) Other resources (e.g., available resources) that are different from the transmission resources of the PRACH (e.g., Preamble part and Data part) described in the above embodiment may be set to another RACH resource (RACH occasion) and may be used for scheduling another uplink channel (e.g., PUSCH, PUCCH, SRS).

[0198] (4) In the above embodiment, PRACH was described as an example of a transmission signal. However, the transmission signal is not limited to PRACH. For example, it may be any other signal that terminal 100 (corresponding to a transmitting device) transmits to base station 200 (corresponding to a receiving device), or it may be a transmission signal that base station 200 (corresponding to a transmitting device) transmits to terminal 100 (corresponding to a receiving device).

[0199] (5) Interlace may be represented, for example, by the number of interlaces in a certain bandwidth (e.g., denoted as M, corresponding to the number of interlaces in a cluster) and the number of PRBs that constitute each interlace (e.g., denoted as N, corresponding to the number of clusters). Furthermore, each interlace is not limited to being distributed in units of PRBs in the frequency domain, but may also be distributed in units consisting of a group of subcarriers smaller than the number of subcarriers that constitute one PRB. Also, the frequency spacing of the resources on which each interlace is placed is not limited to equal spacing.

[0200] (6) The number of clusters in a specific frequency band (e.g., system band), the number of interlaces within each cluster, and the number of subcarriers per interlace (or PRB) are not limited to those exemplified in the above embodiment, but may be other values.

[0201] (7) In the above embodiment, the Block-based interlace design may also be called the "PRB-based interlace design." Interlace may also be called a "cluster." A cluster may also be called a "cluster block." For example, it may be expressed that there are multiple clusters within a cluster block.

[0202] Other embodiments have been described above.

[0203] 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 related technologies lead to the emergence of integrated circuit technologies that replace LSIs, then naturally, these technologies could be used to integrate functional blocks. The application of biotechnology, for example, is a possible possibility.

[0204] 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.

[0205] 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.

[0206] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0207] 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.

[0208] 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.

[0209] A transmitting device in one embodiment of the present disclosure comprises a transmitting circuit for transmitting a data signal and a control circuit for determining a second resource to be used for transmitting the data signal based on a first resource used for transmitting a preamble signal.

[0210] In a transmitting device according to one embodiment of the present disclosure, the first resource is distributed across each of a plurality of bandwidths, and the second resource is located in a portion of the plurality of bandwidths.

[0211] In a transmitting device according to one embodiment of the present disclosure, the portion of the bandwidth is associated with a code sequence set for the preamble signal.

[0212] In a transmitting device according to one embodiment of the present disclosure, the portion of the bandwidth differs for each of the multiple symbols on which the second resource is located.

[0213] In a transmitting device according to one embodiment of the present disclosure, each of the plurality of resources in the first resource includes a plurality of resource units, the second resource includes at least one resource unit of the plurality of resource units included in the portion of the bandwidth, and the at least one resource unit is associated with a code sequence set for the preamble signal.

[0214] In a transmitting device according to one embodiment of the present disclosure, the second resource includes at least one symbol among a plurality of symbols, the at least one symbol is associated with a code sequence set for the preamble signal.

[0215] In a transmitting device according to one embodiment of the present disclosure, the number of bandwidths included in the partial bandwidth differs for each code sequence set for the preamble signal.

[0216] In a transmitting device according to one embodiment of the present disclosure, each of the plurality of bandwidths is composed of a plurality of subcarriers, each of the plurality of subcarriers is assigned a number in each resource unit of the plurality of bandwidths in the first resource, the second resource includes the subcarriers with the same number in the plurality of bandwidths, and the numbers of the subcarriers included in the second resource are associated with a code sequence set for the preamble signal.

[0217] In a transmitting device according to one embodiment of the present disclosure, the data signal and the preamble signal are frequency multiplexed, the first resource is distributed across each of a plurality of bandwidths, the second resource includes resources different from the first resource in each of the plurality of bandwidths, and the second resource is associated with a code sequence set in the preamble signal.

[0218] A receiving device in one embodiment of the present disclosure comprises a receiving circuit for receiving a data signal and a control circuit for determining the resources used to transmit the data signal based on the resources used to transmit the preamble signal.

[0219] In one embodiment of the present disclosure, the transmission method determines the resources to be used for transmitting a data signal based on the resources used for transmitting a preamble signal, and then transmits the data signal.

[0220] In one embodiment of the present disclosure, the receiving method determines the resources used for transmitting a data signal based on the resources used for transmitting a preamble signal, and receives the data signal.

[0221] All disclosures in the specification, drawings, and abstract included in the Japanese application 2018-206734, filed on November 1, 2018, are incorporated herein by reference. [Industrial applicability]

[0222] One embodiment of this disclosure is useful for a mobile communication system. [Explanation of Symbols]

[0223] 100 devices 101,203 Control Unit 102,204 Preamble Resource Settings Section 103,205 Data Resource Configuration Section 104 Preamble generation section 105 Preamble Resource Allocation Section 106 Data generation section 107 Data Resource Allocation Section 108,211 Wireless Transmitter 109,201 antennas 110,202 Wireless receiver 111,207 Demodulation / Decoding Unit 200 base stations 206 Preamble detection unit 208 Scheduling Unit 209 Data Generation Unit 210 Encoding and Modulation Section

Claims

1. A control circuit that, in two-stage random access, associates a first set of random access preambles selected when the path loss between the terminal and the communication device is less than a threshold with a first set of interlace numbers, and associates a second set of random access preambles selected when the path loss between the terminal and the communication device is greater than or equal to the threshold with a second set of interlace numbers, The system comprises a receiver that receives a random access preamble selected based on the aforementioned path loss and receives data using the interlacing of the interlace number associated with the selected random access preamble, The first plurality of interlace numbers associated with the first plurality of random access preambles are consecutive, the second plurality of interlace numbers associated with the second plurality of random access preambles are consecutive, and the first plurality of interlace numbers are different from the second plurality of interlace numbers. Communication device.

2. Each of the first and second sets of random access preambles is generated based on a different code sequence. The communication device according to claim 1.

3. The resources indicated by the first or second interlace numbers are distributed across the frequency domain. The communication device according to claim 1.

4. The receiver receives data signals in a random access procedure using resources indicated by the first or second interlace numbers. The communication device according to claim 1.

5. A portion of the resources in each of the first multiple interlace numbers and a portion of the resources in each of the second multiple interlace numbers are placed within a cluster of physical resource blocks. The communication device according to claim 1.

6. In two-stage random access, a first set of random access preambles selected when the path loss between the terminal and the communication device is less than a threshold is associated with a first set of interlace numbers, and a second set of random access preambles selected when the path loss between the terminal and the communication device is greater than or equal to the threshold is associated with a second set of interlace numbers. The random access preamble selected based on the aforementioned path loss is received, and the data using the interlacing of the interlace number associated with the selected random access preamble is received. The first plurality of interlace numbers associated with the first plurality of random access preambles are consecutive, the second plurality of interlace numbers associated with the second plurality of random access preambles are consecutive, and the first plurality of interlace numbers are different from the second plurality of interlace numbers. Communication method.

7. Each of the first and second sets of random access preambles is generated based on a different code sequence. The communication method according to claim 6.

8. The resources indicated by the first or second interlace numbers are distributed across the frequency domain. The communication method according to claim 6.

9. A random access procedure receives data signals using resources indicated by the first or second set of interlace numbers. The communication method according to claim 6.

10. A portion of the resources in each of the first multiple interlace numbers and a portion of the resources in each of the second multiple interlace numbers are placed within a cluster of physical resource blocks. The communication method according to claim 6.

11. In a two-stage random access process, a process is performed to associate a first set of random access preambles selected when the path loss between the terminal and the communication device is less than a threshold with a first set of interlace numbers, and to associate a second set of random access preambles selected when the path loss between the terminal and the communication device is greater than or equal to the threshold with a second set of interlace numbers. The process of receiving a random access preamble selected based on the aforementioned path loss, and receiving data using the interlacing of the interlace number associated with the selected random access preamble, and controlling the process of: The first plurality of interlace numbers associated with the first plurality of random access preambles are consecutive, the second plurality of interlace numbers associated with the second plurality of random access preambles are consecutive, and the first plurality of interlace numbers are different from the second plurality of interlace numbers. Integrated circuit.

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