Transmitting device, receiving device, transmitting method, and receiving method

Abstract

A terminal capable of appropriately performing random access processing. In the terminal (100), a RACH resource determination unit (104) determines a format of the random access signal based on parameters related to transmission of the random access signal including a preamble portion and a data portion. A radio transmission unit (109) transmits the random access signal based on the format.

Description

[Technical field]

[0001] The present disclosure relates to a transmitting device, a receiving device, a transmitting method, and a receiving method. [Background technology]

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

[0003] In NR, as with LTE-LAA (License-Assisted Access), operation in unlicensed bands is being discussed. In LTE-LAA, operation in unlicensed bands that accompanies operation in licensed bands is supported. On the other hand, in NR, there is a demand to realize operation in unlicensed bands (stand-alone operation) without using licensed bands.

[0004] Therefore, in NR, the introduction of the Physical Random Access Channel (PRACH), which is used by terminals (also called User Equipment (UE)) for initial connection with base stations (also called gNBs), into unlicensed bands is being considered (see, for example, Non-Patent Document 1 or Non-Patent Document 2). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] R2-1809940, LG Electronics Inc., "Considerations on 2-Step CBRA procedure for NR-U SA", 3GPP TSG-RAN WG2 Meeting#AH-1807 [Non-Patent Document 2] 3GPP TR 38.889 V1.1.0, "Study on NR-based Access to Unlicensed Spectrum (Release 16)", 2018-12 [Non-Patent Document 3] 3GPP TS 38.211 V15.3.0, "NR; Physical channels and modulation (Release 15), 2018-09" [Non-Patent Document 4] R1-1809726, Ericsson, "Feature lead summary for UL Signals and Channels", 3GPP TSG-RAN WG1 Meeting#94 Summary of the Invention

[0006] However, random access methods in NR have not been thoroughly studied.

[0007] Non-limiting embodiments of the present disclosure contribute to providing a transmitting device, a receiving device, a transmitting method, and a receiving method that can appropriately perform random access processing.

[0008] A transmitting device according to one embodiment of the present disclosure includes a control circuit that sets a format of a random access signal based on parameters related to transmission of the random access signal including a preamble portion and a data portion, and a transmitting circuit that transmits the random access signal based on the format.

[0009] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0010] According to an embodiment of the present disclosure, random access processing can be performed appropriately.

[0011] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 shows an example of a random access procedure. [Diagram 2] A diagram showing an example of the slot format of msg1 and msg3 [Diagram 3] A diagram showing an example of a slot format for two-stage random access [Figure 4] FIG. 1 is a block diagram showing a partial configuration of a terminal according to a first embodiment; [Diagram 5] FIG. 1 is a block diagram showing a configuration of a part of a base station according to a first embodiment; [Figure 6] FIG. 1 is a block diagram showing a configuration of a terminal according to a first embodiment. [Figure 7] FIG. 1 is a block diagram showing a configuration of a base station according to a first embodiment. [Figure 8] A sequence diagram showing an example of the operation of a terminal and a base station according to the first embodiment. [Figure 9] FIG. 1 is a diagram showing an example of a slot format according to the first embodiment; [Figure 10] FIG. 1 shows an example of a slot format according to the first embodiment. [Figure 11] FIG. 1 is a diagram showing an example of a slot format according to the first embodiment; [Figure 12] FIG. 11 is a block diagram showing a configuration of a base station according to a second embodiment. [Figure 13] FIG. 13 is a diagram showing an example of a slot format according to the second embodiment; [Figure 14] FIG. 13 is a diagram showing an example of a slot format according to the second embodiment; [Figure 15] FIG. 13 is a diagram showing an example of a slot format according to the second embodiment; [Figure 16] FIG. 13 is a diagram showing an example of a slot format according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0014] [Random Access Procedure] For example, the random access procedure in the licensed band is implemented using 4-step random access (also called 4-step Random Access Channel (RACH) or 4-Step Contention Based Random Access (CBRA)).

[0015] In the four-stage random access, for example, as shown in FIG. 1(a), the terminal (UE) transmits 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 a response to the preamble (RA response) and scheduling information including 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 (Radio Resource Control) connection request information such as information about the terminal (e.g., terminal ID, etc.) using the scheduling information indicated by msg2 as the third stage transmission (msg3). Finally, the base station notifies the terminal of control information for the terminal to make 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 from the terminal. In contention resolution, for example, a terminal compares the control signal transmitted by the terminal with the control information for contention resolution included in msg4, and if they are not identical, the terminal starts over from msg1 to avoid RACH collisions among multiple terminals.

[0016] On the other hand, the introduction of two-step random access (also called 2-step RACH or 2-Step CBRA) is being considered as a random access procedure in the unlicensed band of NR (see, for example, Non-Patent Document 1 and Non-Patent Document 2).

[0017] In two-stage random access, for example, as shown in Fig. 1(b), the terminal transmits a preamble part (corresponding to the preamble (or msg1) in Fig. 1(a)) and a data part (corresponding to msg3 in Fig. 1(a)) to the base station as the first stage transmission (msgA). The terminal may transmit the preamble part and the data part simultaneously, at consecutive times, or within a specified time (for example, within one slot).

[0018] Next, as shown in FIG. 1(b), after receiving and decoding msgA, the base station transmits, as the second stage transmission (msgB), to the terminal, the uplink transmission timing and control information for the terminal's RRC connection or control information for contention resolution (corresponding to msg2 and msg4 in FIG. 1(a)).

[0019] By introducing two-stage random access in NR unlicensed bands, it is expected that, for example, LBT (Listen Before Talk) processing will be reduced or random access delay time will be reduced.

[0020] The introduction of two-stage random access is not limited to unlicensed bands. For example, it is being considered to apply two-stage random access to licensed bands and apply it to services for Ultra-Reliable and Low Latency Communications (URLLC) to reduce the latency of data transmission and reception.

[0021] [Slot format] FIG. 2 shows an example of a slot format (for example, called short preamble format A3) in msg1 (for example, preamble) of four-stage random access, and an example of a slot format in msg3 (for example, see Non-Patent Document 3).

[0022] As shown in FIG. 2, msg1 is constructed by repeating multiple sequences ("Seq." (=Sequence) shown in FIG. 2) and adding a CP (Cyclic Prefix) to the beginning.

[0023] Also, msg3 may use the same slot format as a normal uplink data channel (e.g., PUSCH: Physical Uplink Shared Channel). For example, as shown in Fig. 2, msg3 is configured by generating 14 OFDM (Orthogonal Frequency Division Multiplexing) symbols in a slot, each of which is configured by adding a CP to data. Each of the multiple OFDM symbols in msg3 includes, for example, different data.

[0024] For example, as shown in Fig. 2, msg1 (e.g., preamble) is configured by repeating a sequence with a sequence length equal to or less than the FFT window size of an OFDM symbol. In other words, msg1 is configured, for example, with the same multiple sequences. Therefore, even when the preamble and the PUSCH of another terminal are frequency-multiplexed, the signal continuity is ensured at both ends of the FFT window, so that interference from the preamble to the PUSCH (Inter-carrier interference (ICI)) can be suppressed.

[0025] On the other hand, the configuration of the slot format in two-phase random access has not been sufficiently discussed.

[0026] For example, in two-stage random access for licensed bands, a slot format is being considered in which a preamble part is followed by a message part (also called a data part) (see, for example, Non-Patent Document 4). By transmitting the preamble part before the message part, when the preamble part is used as a reference signal for data demodulation of the message part (for example, DMRS: Demodulation Reference Signal), the demodulation processing time of the entire msgA can be reduced.

[0027] On the other hand, in an unlicensed band, the result of the LBT before the terminal starts transmission may be Busy (in other words, NG), and a case may occur in which the terminal is unable to transmit the first part of msgA. FIG. 3 shows an example of a slot format for msgA, which is composed of a preamble part and a data part, in that order. Note that in FIG. 3, for example, the transmission timing (transmission slot timing) of msgA is fixed. For example, in msgA shown in FIG. 3, the result of the LBT may be Busy (NG), and a case may occur in which the terminal is unable to transmit a part of the preamble part.

[0028] For example, when the preamble part is used as the DMRS for the data part, as shown in FIG. 3, if part of the preamble part is not transmitted, the base station may not be able to decode the signal of the data part.

[0029] Also, there are cases where the decoding result of the preamble part is associated with a decoding method such as the MCS (Modulation and Coding Scheme) of the data part. In this case, too, as shown in FIG. 3, if part of the preamble part is not transmitted, the base station may not be able to decode the data part.

[0030] Therefore, in one embodiment of the present disclosure, a two-stage random access slot format that can reduce the impact of the LBT result on performance will be described.

[0031] In the following description, "two-step random access" refers to a random access procedure in which a preamble part (corresponding to msg1 in four-step random access) and a data part (corresponding to msg3 in four-step random access) are transmitted simultaneously, in successive radio resources, or in radio resources within a predetermined time (e.g., within a slot). In other words, two-step random access refers to a random access procedure in which a data part is transmitted together with a preamble part. Alternatively, two-step random access refers to a random access procedure in which a terminal transmits a data part before receiving a response to a preamble (corresponding to msg2 in four-step random access), or transmits a data part without waiting for a response to a preamble.

[0032] (Embodiment 1) [Communication system overview] A communication system according to an embodiment of the present disclosure includes a terminal 100 and a base station 200. In the following description, as an example, the terminal 100 (corresponding to a transmitting device) transmits a PRACH (or a random access signal), and the base station 200 (corresponding to a receiving device) receives the PRACH.

[0033] Fig. 4 is a block diagram showing a configuration of a part of a terminal 100 according to an embodiment of the present disclosure. In the terminal 100 shown in Fig. 4, a RACH resource determination unit 104 (e.g., corresponding to a control circuit) determines a format (e.g., a slot format) of a random access signal based on parameters related to transmission of the random access signal including a preamble part (e.g., a preamble part) and a data part (e.g., a data part). A radio transmission unit 109 (e.g., corresponding to a transmission circuit) transmits the random access signal based on the format.

[0034] Fig. 5 is a block diagram showing a configuration of a part of a base station 200 according to an embodiment of the present disclosure. In the base station 200 shown in Fig. 5, a RACH resource control unit 201 (e.g., corresponding to a control circuit) determines a format of a random access signal based on a parameter related to transmission of the random access signal. A radio receiving unit 206 (e.g., corresponding to a receiving circuit) receives the random access signal based on the format.

[0035] [Device configuration] FIG. 6 is a block diagram showing a configuration of terminal 100 according to the present embodiment.

[0036] In FIG. 6 , terminal 100 includes antenna 101, radio receiving section 102, demodulation and decoding section 103, RACH resource determination section 104, preamble generation section 105, data generation section 106, multiplexing section 107, LBT section 108, and radio transmission section 109.

[0037] Radio receiving section 102 performs reception processing such as down-conversion and A / D conversion on the signal transmitted from base station 200 via antenna 101, and outputs the received signal obtained by the reception processing to demodulation and decoding section 103.

[0038] The signal transmitted from the base station 200 includes, for example, control information including radio resource information used by the terminal 100 for two-stage random access transmission, a PRACH response data signal (for example, msgB shown in FIG. 1(b)), etc. Also, for example, the radio resource information includes RACH resource information such as sequence information for the preamble part, frequency allocation information for the preamble part, MCS information for the data part, frequency allocation information for the data part, and slot format information.

[0039] The demodulation and decoding unit 103 demodulates and decodes the received signal input from the radio receiving unit 102. For example, the demodulation and decoding unit 103 demodulates and decodes higher layer signaling (also called higher layer signaling, RRC signaling, or higher layer parameter), downlink control information (DCI), etc., and outputs RACH resource information from the decoded signals to the RACH resource determination unit 104.

[0040] Furthermore, if the demodulation and decoding unit 103 can correctly receive the response data signal of the PRACH, the RRC connection process by two-stage random access is completed.

[0041] For example, based on the RACH resource information input from the demodulation and decoding unit 103, the RACH resource determination unit 104 outputs resource information for the preamble part to the preamble generation unit 105 and outputs resource information for the data part to the data generation unit 106. In addition, the RACH resource determination unit 104 sets a slot format (for example, the format of msgA) for two-stage random access and outputs setting information of the slot format to the multiplexing unit 107.

[0042] The preamble generating unit 105 generates a preamble based on the resource information input from the RACH resource determining unit 104. For example, the preamble generating unit 105 randomly selects one preamble number from a group of preamble numbers, and generates a CS-ZC sequence using a sequence number and a cyclic shift (CS) amount corresponding to the selected preamble number. The preamble generating unit 105 assigns the generated CS-ZC sequence to, for example, a frequency resource indicated in the resource information. The preamble generating unit 105 also performs, for example, an Inverse Fast Fourier Transform (IFFT) process on the CS-ZC sequence to convert it into a time domain signal. The preamble generating unit 105 then repeats the CS-ZC sequence, which is a time domain signal, for a set number of symbols, adds a CP length of an arbitrary time length, and outputs the generated signal (for example, a short preamble format signal, for example, a signal of the same format as the preamble shown in FIG. 2) to the multiplexing unit 107 as a preamble part signal.

[0043] In addition, the sequence used for the preamble part signal is not limited to the ZC sequence, but may be any sequence with good correlation characteristics. Also, the preamble part signal is not limited to being generated by repeating a sequence with a short sequence length. For example, if interference can be reduced by not frequency-multiplexing with other uplink channels (e.g., PUSCH) different from the PRACH, or by providing a guard band, the preamble part signal may be generated by adding a CP to a sequence with a long sequence length equivalent to the time length of the preamble part.

[0044] In addition, when a preamble number for a preamble part is notified from base station 200 to terminal 100 by a downlink control signal (e.g., DCI), preamble generating section 105 may generate a CS-ZC sequence using a sequence number and a cyclic shift amount corresponding to the notified preamble number.

[0045] The data generating unit 106 generates a data signal (e.g., equivalent to msg3 in four-step random access) including, for example, RRC connection request information such as a terminal ID (or information used for connection probability). The data generating unit 106 encodes and modulates (e.g., QPSK or 16QAM) the generated data signal based on, for example, resource information input from the RACH resource determining unit 104. The data generating unit 106 also generates an OFDM symbol by allocating the modulated signal (data sequence) to a frequency resource based on the resource information, performing OFDM modulation (e.g., IFFT processing), and adding a CP. The data generating unit 106 also outputs a signal formed by arranging the generated OFDM symbols in the time domain by a predetermined number of symbols to the multiplexing unit 107 as a data part signal. Note that the data part signal may include a data demodulation reference signal (e.g., DMRS) for improving channel estimation accuracy or the like.

[0046] The multiplexing unit 107 time-multiplexes the preamble part signal input from the preamble generating unit 105 and the data part signal input from the data generating unit 106 based on the setting information of the slot format of the two-stage random access input from the RACH resource determining unit 104, and outputs the multiplexed signal to the LBT unit 108 as a msgA signal of the two-stage random access.

[0047] For example, when the msgA signal input from the multiplexing unit 107 is transmitted in an unlicensed band, the LBT unit 108 performs LBT processing. For example, when the LBT result immediately before the transmission timing of the slot is Busy (NG), the LBT unit 108 continues carrier sensing for a determined time length. On the other hand, for example, when the LBT result becomes Idle (OK), the LBT unit 108 outputs the msgA signal from the timing when the LBT result became Idle to the wireless transmission unit 109. In other words, the LBT unit 108 outputs to the wireless transmission unit 109 the signal excluding the msgA signal for the time when the LBT result is Busy from the transmission start timing of the slot (in other words, the leading portion of the msgA signal).

[0048] In the case of a licensed band, for example, LBT processing in LBT unit 108 is not required.

[0049] The wireless transmitting unit 109 performs transmission processing such as D / A conversion, up-conversion, and amplification on the signal input from the LBT unit 108, and transmits the wireless signal obtained by the transmission processing (for example, the msgA signal in two-stage random access) from the antenna 101 to the base station 200.

[0050] [Base station configuration] FIG. 7 is a block diagram showing a configuration of base station 200 according to the present embodiment.

[0051] In FIG. 7, base station 200 includes a RACH resource control unit 201, a control information generation unit 202, an LBT unit 203, a radio transmission unit 204, an antenna 205, a radio reception unit 206, a separation unit 207, a preamble detection unit 208, and a data demodulation and decoding unit 209.

[0052] The RACH resource control unit 201, for example, controls the RACH resources available in the cell of the base station 200, and outputs RACH resource information indicating the determined RACH resources to the control information generation unit 202 and the separation unit 207. For example, the RACH resource control unit 201 sets a slot format (for example, the format of msgA) for two-stage random access.

[0053] The RACH resource information includes, for example, radio resource information used for transmitting two-stage random access in terminal 100 (e.g., sequence information for the preamble part, frequency allocation information for the preamble part, MCS information for the data part, frequency allocation information for the data part, slot format information, etc.).

[0054] The control information generator 202 generates control information including the RACH resource information input from the RACH resource controller 201. The control information generator 202 outputs a signal including the generated control information to the LBT unit 203, for example.

[0055] The control information may be included in, for example, higher layer signaling or downlink control information (DCI). The higher layer signaling may be, for example, RACH-Configuration in NR (for example, RACH-ConfigCommon, RACH-ConfigDedicated, etc.). The downlink control information may be, for example, DCI format1_0 in NR.

[0056] Moreover, it is not necessary for all the control information to be notified simultaneously to terminal 100. For example, some of the control information may be notified to terminal 100 as cell common information, or as semi-static notification information or dynamic notification information (DCI, etc.). Also, some of the control information may be defined in a specification as system common information, for example, and may not be notified from base station 200 to terminal 100.

[0057] LBT section 203 performs LBT processing when the control information input from control information generating section 202 is to be transmitted in an unlicensed band. For example, when the LBT result is Idle (OK), LBT section 203 outputs control information from the timing when the LBT result became Idle to wireless transmitting section 204. Note that in the case of a licensed band, LBT processing in LBT section 203 is not necessary.

[0058] Radio transmitting section 204 performs transmission processing such as D / A conversion, up-conversion, and amplification on the signal input from LBT section 203 , and transmits the radio signal obtained by the transmission processing from antenna 205 to terminal 100 .

[0059] The radio receiving unit 206 performs reception processing such as down-conversion and A / D conversion on a RACH signal (e.g., msgA in two-stage random access) from the terminal 100 received via the antenna 205 in a RACH transmission resource notified to the terminal 100 in the cell of the base station 200. The radio receiving unit 206 outputs the signal obtained by the reception processing to the demultiplexing unit 207.

[0060] The demultiplexing section 207 separates a preamble part signal and a data part signal from the msgA signal input from the radio receiving section 206, based on, for example, RACH resource information (for example, time resource information, frequency resource information, or slot format information) notified to terminal 100 in the cell input from RACH resource control section 201. The demultiplexing section 207 outputs the preamble part signal to a preamble detection section 208 and outputs the data part signal to a data demodulation and decoding section 209.

[0061] The preamble detection unit 208 generates a replica signal for detecting a preamble part signal, using a sequence number and a CS number corresponding to each preamble number of a group of preamble numbers available in the cell of the base station 200. The preamble detection unit 208 performs a correlation process between the generated replica signal and the preamble part signal input from the separation unit 207, detects the preamble number, and estimates the transmission timing. The preamble detection unit 208 outputs the correlation result (in other words, a channel estimation value) to the data demodulation and decoding unit 209. The preamble detection unit 208 may also output the detection result (for example, the preamble number) to the data demodulation and decoding unit 209.

[0062] The Data demodulation / decoding unit 209 demodulates and decodes the Data part signal input from the separation unit 207 using the channel estimation value input from the preamble detection unit 208, and outputs the decoding result (received data). When the preamble number is associated with an MCS for Data demodulation, the Data demodulation / decoding unit 209 selects an MCS from the preamble number input from the preamble detection unit 208, and demodulates and decodes the Data part signal based on the selected MCS.

[0063] [Operation of terminal 100 and base station 200] An example of the operation of terminal 100 and base station 200 having the above configuration will be described.

[0064] FIG. 8 is a sequence diagram showing an example of the operation of the terminal 100 (FIG. 6) and the base station 200 (FIG. 7).

[0065] 8, base station 200 notifies (in other words, broadcasts) cell information including RACH resource information used by terminal 100 for two-stage random access transmission to terminal 100 (ST101). For example, higher layer signaling or downlink control information (DCI) may be used to notify the RACH resource information.

[0066] Terminal 100 generates, for example, a preamble part signal included in the msgA signal based on RACH resource information indicated in the cell information (ST102), and generates a data part signal included in the msgA signal (ST103).

[0067] Terminal 100 time-multiplexes the generated preamble part signal and data part signal based on slot format information (for example, slot format of msgA) indicated in the RACH resource information to generate a msgA signal (ST104).

[0068] Terminal 100 also performs LBT (ST105). Terminal 100 transmits a msgA signal (PRACH signal) to base station 200 when the LBT result becomes Idle (OK) (ST106). The msgA signal includes, for example, a signal excluding a signal with a time length for which the LBT result is NG from the beginning of the slot.

[0069] Based on RACH resource information (e.g., slot format of msgA) notified to terminal 100, base station 200 separates a preamble part signal and a data part signal from the msgA signal (ST107). Base station 200 calculates a channel estimation value using the preamble part signal and detects a preamble number (ST108). Then, base station 200 demodulates and decodes the data part signal using the channel estimation value (or the preamble number) (ST109).

[0070] [How to set slot format for two-stage random access] Next, an example of a method for setting a slot format for two-stage random access will be described.

[0071] For example, the two-stage random access slot format is a format in which at least a part of a data part is placed before a preamble part, as shown in Fig. 9 and Fig. 10. In other words, the terminal 100 and the base station 200 set the slot format to a configuration in which all or a part of the data part is transmitted before transmitting a preamble part signal, for example.

[0072] For example, in the slot format shown in Fig. 9, a configuration is set in which all of the Data part signals are transmitted before the transmission of the Preamble part signal. In other words, in the slot format shown in Fig. 9, the Preamble part signal is transmitted after the Data part signal.

[0073] Also, for example, in the slot format shown in FIG. 10, some Data part signals are transmitted before transmitting a Preamble part signal, and the remaining Data part signals are transmitted after the Preamble part signal.

[0074] 9 or 10, the probability that the terminal 100 can transmit the entire preamble part signal increases even if the LBT result is Busy and the terminal 100 cannot transmit the beginning part of msgA. In other words, when the LBT result is Busy and the terminal 100 cannot transmit the beginning part of msgA, the probability that the part of the data part signal is not transmitted increases.

[0075] If the base station 200 can correctly receive the preamble part signal transmitted from the terminal 100, there is a possibility that the base station 200 can decode the data part signal. Therefore, in the slot format shown in Fig. 9 or Fig. 10, the probability that the base station 200 can correctly receive the preamble part signal increases, and therefore the probability that the base station 200 can decode the data part signal increases.

[0076] Furthermore, when the slot format shown in FIG. 9 or FIG. 10 is set, even if base station 200 cannot decode the Data part signal, base station 200 can request retransmission of the Data part signal, for example, transition to four-stage random access (in other words, fallback), and retransmission of the Preamble part signal becomes unnecessary.

[0077] Thus, according to this embodiment, terminal 100 determines, for example, the slot format shown in Fig. 9 or 10, and transmits msgA (in other words, a random access signal) based on the determined slot format. Also, base station 200 determines, for example, the slot format shown in Fig. 9 or 10, and receives msgA (in other words, a random access signal) based on the determined slot format.

[0078] For example, by setting the slot format shown in Fig. 9 and Fig. 10, it is possible to reduce the impact on random access performance caused by non-transmission of a part of the msgA signal due to the LBT result. Therefore, according to this embodiment, terminal 100 and base station 200 can appropriately perform random access processing.

[0079] Also, as shown in Fig. 9, all of the Data part signals are transmitted before the Preamble part signal, so that the possibility that the Preamble part signal is not transmitted due to the LBT result can be further reduced compared to Fig. 10. Therefore, in Fig. 9, the impact on random access performance can be further reduced.

[0080] Furthermore, as shown in FIG. 10, by transmitting a part of the Data part signal before the Preamble part signal, for example, base station 200 can receive the Preamble part signal used as the DMRS earlier, and the decoding time of msgA can be reduced.

[0081] 9 and 10 are merely examples, and the slot format is not limited to these. For example, the relationship between the number of symbols of the Data part arranged before the Preamble part and the number of symbols of the Data part arranged after the Preamble part is not limited to the example shown in FIG.

[0082] Furthermore, the slot format of the above-mentioned RACH signal (for example, msgA) may be determined based on parameters related to the RACH signal. Variations of this embodiment will be described below.

[0083] (Variation 1 of the first embodiment) The slot format described in the present embodiment may be used in a band used for transmitting a RACH signal not only in an unlicensed band but also in a licensed band. For example, by making the slot format common to the licensed band and the unlicensed band, the transmission and reception processing of random access in the terminal 100 and the base station 200 can be simplified.

[0084] (Variation 2 of the first embodiment) The slot format described in this embodiment (eg, FIG. 9 or FIG. 10) may be applied when the transmission of the RACH signal satisfies a specific communication condition.

[0085] For example, the slot format shown in Fig. 9 or 10 is applied to an unlicensed band in which LBT processing is performed, and may not be applied to a band different from the unlicensed band (for example, a licensed band). As a result, for example, in an unlicensed band, in transmitting msgA, all or a part of the Data part signal is transmitted before the Preamble part signal.

[0086] On the other hand, for example, since the LBT process is not performed in the licensed band, the slot format of the two-stage random access may be configured to transmit the preamble part signal and the data part signal in that order, as shown in Fig. 11. This allows the decoding time of msgA to be reduced in the licensed band.

[0087] (Variation 3 of the First Embodiment) The slot format of the two-stage random access (in other words, the transmission order of the preamble part signal and the data part signal) may be set (in other words, may be switched) on a cell-by-cell basis.

[0088] For example, in a cell in a dense cell environment, the probability that the LBT result is busy is high. Therefore, in a cell in a dense cell environment, for example, the slot format shown in FIG. 9 may be applied, which can further reduce the impact of the LBT result on random access performance.

[0089] On the other hand, in a cell that exists in an environment different from an environment where cells are densely packed (for example, an environment where cells are scattered), the slot format shown in FIG. 10 or FIG. 11 may be applied, for example, to reduce the decoding time.

[0090] (Variation 4 of the First Embodiment) The terminal 100 and the base station 200 may control application of the slot format according to the category of the LBT (in other words, carrier sense).

[0091] For example, category 1 is an LBT that can transmit a signal without carrier sensing, and category 2 is an LBT that can transmit a signal when the result of carrier sensing for a predetermined time period (e.g., 25 us) is Idle (OK). Category 1 or category 2 LBT is suitable for the case where the terminal 100 transmits msgA at a specific slot timing because it can transmit a signal with short carrier sensing.

[0092] On the other hand, category 3 or category 4 is an LBT that can be transmitted when the result of carrier sense in a specific backoff time is Idle (OK). Category 3 or category 4 LBT is an LBT that is difficult to transmit in accordance with a specific slot timing, and msgA is transmitted in a slot timing (e.g., RACH resource) after the LBT result becomes Idle (OK). Therefore, although delay increases in category 3 or category 4, the problem of a part of the beginning of msgA not being transmitted due to the LBT result does not occur.

[0093] Therefore, terminal 100 and base station 200 may determine, for example, to apply the slot format shown in Fig. 9 or 10 when using an LBT of category 1 or category 2. In other words, terminal 100 and base station 200 may determine, for example, not to apply the slot format shown in Fig. 9 or 10 when using an LBT of category 3 or category 4. Terminal 100 and base station 200 may determine, for example, to apply the slot format shown in Fig. 11 when using an LBT of category 3 or category 4.

[0094] The category of the LBT used by the terminal 100 is defined according to, for example, a channel occupancy time (COT) condition or a channel type. Therefore, the terminal 100 can recognize the category of the LBT used by the terminal 100.

[0095] (Variation 5 of the First Embodiment) Terminal 100 and base station 200 may control application of the slot format according to a RACH classification (for example, called a RACH type) indicating a type of random access transmission.

[0096] There are two types of RACH: CBRA (Contention Based Random Access) and CFRA (Contention Free Random Access). CBRA is a RACH that is transmitted at the initiative of the terminal, and the slot timing of msgA is determined by the terminal. On the other hand, CFRA is a RACH that is transmitted at the initiative of the base station (for example, an instruction or trigger by a downlink control channel), and the transmission of msgA from each terminal is scheduled so as to prevent collision between multiple terminals.

[0097] For example, in the case of CFRA, terminal 100 transmits msgA at a specific slot timing, so there is a high possibility that a problem will occur in which a portion of the beginning of msgA is not transmitted. Therefore, terminal 100 and base station 200 may determine to apply, for example, the slot format shown in Fig. 9 or 10 when the RACH type is CFRA. Also, for example, terminal 100 and base station 200 may determine to apply the slot format shown in Fig. 11 when the RACH type is CBRA.

[0098] (Embodiment 2) A terminal according to this embodiment has a basic configuration in common with terminal 100 according to the first embodiment, and therefore will be described with reference to FIG.

[0099] Fig. 12 is a block diagram showing a configuration example of base station 300 according to this embodiment. In Fig. 12, the same components as those in embodiment 1 (see Fig. 7) are given the same reference numerals, and the description thereof will be omitted. For example, base station 300 shown in Fig. 12 differs from the configuration of base station 200 shown in Fig. 7 in that propagation delay estimation section 301 is added.

[0100] In the base station 300, a propagation delay estimation unit 301 estimates an expected propagation delay time (for example, a maximum propagation delay time) between the base station 300 and the terminal 100 based on an assumed coverage area of ​​the base station 300, etc. The propagation delay estimation unit 301 outputs the estimation result to the RACH resource control unit 302.

[0101] The RACH resource control unit 302 determines the CP length of the preamble part according to, for example, the estimation result of the propagation delay time input from the propagation delay estimation unit 301. For example, the RACH resource control unit 302 sets a CP length equal to or greater than the maximum propagation delay time in order to reduce inter-symbol interference (ISI) caused by delayed waves. Then, the RACH resource control unit 302 controls the configuration of the slot format of the data part based on the estimation result of the maximum propagation delay time or the CP length of the preamble part.

[0102] For example, the RACH resource control unit 302 controls the configuration of the slot format of the data part based on the result of comparing the maximum propagation delay time or the CP length of the preamble part with a threshold value. For example, when the maximum propagation delay time is represented by the CP length of the preamble part, the CP length of another uplink channel may be set as the threshold value (an example will be described later).

[0103] [How to set the slot format for the Data part for two-stage random access] Next, an example of a method for setting the slot format of a data part for two-stage random access according to this embodiment will be described.

[0104] [Data part transmission control] The RACH signal (e.g., msgA signal) is transmitted even before initial synchronization, that is, before transmission timing control. Therefore, in order to reduce interference, the CP length of the preamble part is set in each cell, for example, taking into consideration the maximum propagation delay time expected from the distance between base station 300 and terminal 100.

[0105] On the other hand, the CP length of other uplink channels (e.g., PUSCH, etc.) different from RACH is set to a time length defined according to SCS (Sub-Carrier Spacing), for example. Also, the other uplink channels may be transmitted under transmission timing control. Therefore, the CP length of the other uplink channels is not dependent on the distance between base station 300 and terminal 100, but is set in consideration of, for example, the maximum delay amount of delayed waves. For example, the CP length of the other uplink channels may be defined by the system.

[0106] Here, for example, when msgA and PUSCH are frequency-multiplexed, it is necessary to take into consideration the suppression of interference (inter-carrier interference (ICI)) with other uplink channels (e.g., PUSCH) for the data part as well as the preamble part of msgA.

[0107] For example, as shown in Fig. 13, when the CP length (propagation delay length) of the preamble part exceeds the CP length of the PUSCH, the continuity of the signal is not ensured at both ends of the FFT window of the PUSCH in the data part. Therefore, as shown in Fig. 13, since data part signals of different OFDM symbols are mixed in the FFT window of the PUSCH, the orthogonality of OFDM is lost, and ICI interference occurs from the RACH (for example, the data part signal of msgA) to the PUSCH.

[0108] Therefore, when the maximum propagation delay time expected between the base station 300 and the terminal 100 or the CP length of the preamble part is greater than the CP length (in other words, a threshold) of another uplink channel (e.g., PUSCH or SRS, etc.), the RACH resource control unit 302 instructs the terminal 100 to stop transmitting the Data part signal (in other words, set to non-transmission). For example, when the terminal 100 receives an instruction to stop transmitting the Data part signal, it transmits the Preamble part signal in the msgA signal, but does not transmit the Data part signal.

[0109] Also, for example, the RACH resource control section 302 may instruct the terminal 100, which instructs the terminal 100 to stop transmitting the Data part in msgA, to apply four-stage random access (in other words, fallback).

[0110] This makes it possible to suppress ICI interference from the RACH to other uplink channels.

[0111] On the other hand, when the CP length of the preamble part is equal to or less than the CP length of another uplink channel (in other words, the threshold), the RACH resource control unit 302 instructs the terminal 100 to transmit a Data part signal. In this case, for example, as shown in Fig. 14, Data part signals of different OFDM symbols are not mixed in the FFT window of the PUSCH, so that signal continuity is ensured at both ends of the FFT window of the PUSCH, and ICI interference from the RACH to the PUSCH does not occur.

[0112] [CP length control of Data part] In order to reduce interference (ICI) from the RACH to other uplink channels (e.g., PUSCH), the RACH resource control unit 302 may control the CP length of the data part according to the CP length of the preamble part (in other words, the estimated result of the propagation delay time).

[0113] For example, when the CP length of the preamble part (e.g., equivalent to the expected maximum propagation delay amount) is equal to or less than the CP length of the PUSCH (in other words, a threshold), the RACH resource control unit 302 sets the CP length of the data part to the same value as the CP length of the PUSCH. In this case, for example, as shown in FIG. 14, neither the preamble part nor the data part causes interference with the PUSCH.

[0114] On the other hand, when the CP length of the preamble part is longer than the CP length of the PUSCH (in other words, the threshold), the RACH resource control section 302 sets the CP length of the data part to be longer in order to prevent interference. That is, when the CP length (or the propagation delay time) of the preamble part is greater than the threshold, the CP length of the data part is longer than when the CP length of the preamble part is equal to or less than the threshold.

[0115] For example, as shown in Fig. 15, terminal 100 uses either the odd-numbered or even-numbered OFDM symbol of the Data part as a CP for the next OFDM symbol (in other words, the other of the odd-numbered or even-numbered OFDM symbols of the Data part). As a result, signal continuity at both ends of the FFT window of the PUSCH is ensured by the CP for either the odd-numbered or even-numbered OFDM symbol of the Data part, so that there is a high possibility that ICI interference from the RACH to the PUSCH will not occur.

[0116] Thus, according to the present embodiment, base station 300 determines the slot format of msgA (for example, the setting of the Data part in msgA) based on a parameter related to the transmission of a RACH signal (for example, the maximum propagation delay time or the CP length of the preamble part). Terminal 100 transmits the msgA signal based on the slot format determined based on the parameter related to the transmission of a RACH signal (for example, the maximum propagation delay time or the CP length of the preamble part).

[0117] As a result, in this embodiment, even if the RACH and other uplink channels (e.g., PUSCH) are assigned to adjacent frequency resources, it is possible to reduce interference (ICI) from the RACH to other uplink channels. Therefore, according to this embodiment, the terminal 100 and the base station 300 can appropriately perform random access processing.

[0118] In addition, in FIG. 13, FIG. 14, and FIG. 15, PUSCH is used as an example of another uplink channel different from RACH, but the other uplink channel is not limited to PUSCH and may be another uplink channel (for example, PUCCH (Physical Uplink Control Channel)).

[0119] The embodiments of the present disclosure have been described above.

[0120] (Other embodiments) (1) The method of the first embodiment and the method of the second embodiment may be combined. For example, as shown in Fig. 16, all (or part) of the Data part of msgA may be transmitted before the Preamble part, as in the first embodiment. Also, as shown in Fig. 16, the CP length of the Data part may be changed according to the CP length of the Preamble part, as in the second embodiment.

[0121] (2) In the above embodiment, msgA, which is a signal for two-stage random access, has been described. However, the signal to which an embodiment of the present disclosure is applied is not limited to msgA. For example, it may be another signal transmitted from the terminal 100 (corresponding to the transmitting device) to the base station 200 (corresponding to the receiving device), or it may be a transmission signal transmitted from the base station 200 (corresponding to the transmitting device) to the terminal 100 (corresponding to the receiving device).

[0122] For example, the preamble part may be replaced with an SRS, and the data part may be replaced with a PUSCH. In this case, the above-described embodiment may be applied to the slot format of the SRS and the PUSCH when the SRS and the PUSCH are transmitted in the same slot.

[0123] Other embodiments have been described above.

[0124] The present disclosure can be realized by software, hardware, or software linked to hardware. Each functional block used in the description of the above embodiment may be realized partially or entirely as an LSI, which is an integrated circuit, and each process described in the above embodiment may be controlled partially or entirely by one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of one chip to include some or all of the functional blocks. The LSI may have input and output data. Depending on the degree of integration, the LSI may be called an IC, a system LSI, a super LSI, or an ultra LSI. The method of integration is not limited to LSI, and may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. In addition, a field programmable gate array (FPGA) that can be programmed after LSI manufacture, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. The present disclosure may be realized as digital processing or analog processing. Furthermore, if a new integrated circuit technology that can replace LSI appears due to the progress of semiconductor technology or a derivative technology, it is possible to integrate the functional blocks using that technology. The application of biotechnology is also a possibility.

[0125] The present disclosure may be implemented in any type of apparatus, device, or system with communications capabilities (collectively, communications apparatus), including, but not limited to, telephones (e.g., cell phones, smartphones, etc.), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks, etc.), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices, etc.), game consoles, digital book readers, telehealth / telemedicine devices, communications-enabled vehicles or mobile conveyances (e.g., cars, planes, ships, etc.), and combinations of the above-mentioned devices.

[0126] Communications Equipment includes, but is not limited to portable or mobile equipment, non-portable or fixed equipment, devices and systems of any kind, such as smart home devices (appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines and any other "Things" that may exist on an Internet of Things (IoT) network.

[0127] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0128] A communications apparatus also includes devices, such as controllers and sensors, connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0129] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0130] A transmitting device according to one embodiment of the present disclosure includes a control circuit that sets a format of a random access signal based on parameters related to transmission of the random access signal including a preamble portion and a data portion, and a transmitting circuit that transmits the random access signal based on the format.

[0131] In a transmitting device according to an embodiment of the present disclosure, the format is a first format in which at least a portion of the data portion is arranged before the preamble portion.

[0132] In a transmitting device according to an embodiment of the present disclosure, the control circuit applies the first format when transmitting the random access signal in an unlicensed band.

[0133] In a transmitting device according to an embodiment of the present disclosure, the control circuit determines whether or not to apply the first format depending on a carrier sense category.

[0134] In a transmitting device according to an embodiment of the present disclosure, the control circuit determines whether to apply the first format depending on a type of random access transmission.

[0135] In a transmitting device according to an embodiment of the present disclosure, the control circuit controls a configuration of the data section in accordance with a propagation delay.

[0136] In a transmitting device according to an embodiment of the present disclosure, the control circuit sets the signal of the data portion to not be transmitted when the propagation delay is greater than a threshold value.

[0137] In a transmitting device according to an embodiment of the present disclosure, a cyclic prefix (CP) length of the data section when the propagation delay is greater than a threshold is longer than the CP length of the data section when the propagation delay is equal to or less than the threshold.

[0138] In a transmitting device according to one embodiment of the present disclosure, the control circuit sets a symbol having either an even number or an odd number in the data section to the CP for the symbol having the other number.

[0139] In a transmitting device according to one embodiment of the present disclosure, the propagation delay is represented by a cyclic prefix (CP) length or a cyclic shift (CS) amount of the preamble portion, and the threshold value is a CP length in a channel other than a random access channel.

[0140] In a transmitting device according to one embodiment of the present disclosure, the propagation delay is represented by a cyclic prefix (CP) length or a cyclic shift (CS) amount of the preamble section, and when the CP length of the preamble section is equal to or less than a threshold, the CP length of the data section is set to the CP length of another channel other than the random access channel.

[0141] A receiving device according to one embodiment of the present disclosure includes a control circuit that sets a format of a random access signal based on parameters related to transmission of the random access signal including a preamble portion and a data portion, and a receiving circuit that receives the random access signal based on the format.

[0142] A transmission method according to one embodiment of the present disclosure sets a format of a random access signal based on parameters related to transmission of a random access signal including a preamble portion and a data portion, and transmits the random access signal based on the format.

[0143] A receiving method according to one embodiment of the present disclosure includes setting a format of a random access signal based on parameters related to transmission of the random access signal including a preamble portion and a data portion, and receiving the random access signal based on the format.

[0144] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2018-247266, filed on December 28, 2018, are incorporated herein by reference in their entirety. [Industrial Applicability]

[0145] An embodiment of the present disclosure is useful in a mobile communication system. [Explanation of symbols]

[0146] 100 devices 101,205 Antennas 102,206 Radio receiver 103 Demodulation and Decoding Section 104 RACH resource determination unit 105 Preamble generation section 106 Data generation section 107 Multiplex section 108,203 LBT Department 109,204 Radio transmitter 200,300 base stations 201,302 RACH resource control section 202 Control information generation unit 207 Separation section 208 Preamble detection section 209 Data demodulation and decoding section 301 Propagation Delay Estimation Unit

Claims

1. a control circuit for setting a format of the random access signal based on parameters related to transmission of the random access signal including a preamble portion and a data portion; a transmission circuit for transmitting the random access signal based on the format; Equipped with the format is a first format in which at least a part of the data section is arranged before the preamble section; Transmitting device.

2. The control circuit applies the first format when transmitting the random access signal in an unlicensed band. The transmitting device according to claim 1 .

3. the control circuit determines whether or not to apply the first format depending on a carrier sense category. The transmitting device according to claim 1 .

4. The control circuit determines whether to apply the first format depending on a type of random access transmission. The transmitting device according to claim 1 .

5. The control circuit controls a configuration of the data section in response to a propagation delay. The transmitting device according to claim 1 .

6. When the propagation delay is greater than a threshold value, the control circuit sets the signal of the data portion to not be transmitted. The transmitting device according to claim 5.

7. A cyclic prefix (CP) length of the data section when the propagation delay is greater than a threshold is longer than the CP length of the data section when the propagation delay is equal to or less than the threshold. The transmitting device according to claim 5.

8. The control circuit sets a symbol having either an even number or an odd number in the data portion to the CP for the symbol having the other number, the even number or the odd number. The transmitting device according to claim 7.

9. The propagation delay is represented by a cyclic prefix (CP) length or a cyclic shift (CS) amount of the preamble part, The threshold is a CP length in a channel other than the random access channel. The transmitting device according to claim 6.

10. The propagation delay is represented by a cyclic prefix (CP) length or a cyclic shift (CS) amount of the preamble part, When the CP length of the preamble portion is equal to or less than a threshold, the CP length of the data portion is set to a CP length in a channel other than a random access channel. The transmitting device according to claim 5.

11. a control circuit for setting a format of the random access signal based on parameters related to transmission of the random access signal including a preamble portion and a data portion; a receiving circuit for receiving the random access signal based on the format; Equipped with the format is a first format in which at least a part of the data section is arranged before the preamble section; Receiving device.

12. Setting a format of the random access signal based on parameters related to transmission of the random access signal including a preamble portion and a data portion; Transmitting the random access signal based on the format; the format is a first format in which at least a part of the data section is arranged before the preamble section; Transmission method.

13. Setting a format of the random access signal based on parameters related to transmission of the random access signal including a preamble portion and a data portion; receiving the random access signal based on the format; the format is a first format in which at least a part of the data section is arranged before the preamble section; Receiving method.

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