WO2024090188A1

WO2024090188A1 - Communication device, communication terminal, communication system, communication method, and program

Info

Publication number: WO2024090188A1
Application number: PCT/JP2023/036667
Authority: WO
Inventors: 高広笹木
Original assignee: 日本電気株式会社
Priority date: 2022-10-26
Filing date: 2023-10-10
Publication date: 2024-05-02

Abstract

An objective of the present invention is to provide a communication device that can reduce the load of monitoring a PDCCH. A communication device according to the present disclosure comprises: a control unit that uses both the slot length of a slot constituting a radio frame and the frame rate of data to determine a first period using the slot as a unit and a second period using a symbol constituting the slot as a unit and that uses the first period and the second period to determine a symbol number used for transmitting scheduling information of the data; and a communication unit that transmits the first period and a value related to the second period to a communication terminal.

Description

COMMUNICATION DEVICE, COMMUNICATION TERMINAL, COMMUNICATION SYSTEM, COMMUNICATION METHOD, AND PROGRAM

This disclosure relates to a communication device, a communication terminal, a communication system, a communication method, and a program.

3GPP (3rd Generation Partnership Project), which develops wireless communication standards, is currently studying 5G (5th Generation). 5G may also be referred to as NR (New Radio). In NR, the downlink data channel received by the UE (User Equipment) or the uplink data channel transmitted by the UE is scheduled using downlink control information (DCI). DCI is transmitted from the base station to the UE via the PDCCH (Physical Downlink Control Channel). Here, UE is used as a general term for terminals in 3GPP. The base station may also be referred to as an access network node or gNB (g Node B), etc.

For example, Non-Patent Document 1 discloses processing related to PDCCH monitoring in NR. Specifically, the UE determines the PDCCH monitoring occasion in the active DL BWP (Downlink Bandwidth Part). The PDCCH monitoring occasion is indicated using one of the slot numbers of multiple slots that make up a frame. The UE monitors PDCCH candidates using a search space of T (T is an integer) consecutive slots starting from the slot number indicating the PDCCH monitoring occasion.

Non-Patent Document 1 also discloses that the UE monitors the PDCCH in specific symbols. Specifically, the UE is instructed by monitoringSymbolsWithinSlot to monitor the PDCCH in three consecutive symbols in all slots that the UE monitors.

Non-patent document 2 discloses that monitoringSymbolsWithinSlot is represented as a bitmap of 14 bits contained in one slot. Each bit represents an OFDM symbol. The UE attempts to receive the PDCCH at the symbol corresponding to the bit set to "1". Receiving the PDCCH may be rephrased as detecting the PDCCH. The UE can receive or detect DCI by receiving the PDCCH.

Here, the base station needs to schedule the PDCCH according to the timing of data to be transmitted to the UE or data to be transmitted by the UE. For example, if the frame rate of data transmitted by the base station to the UE is 120 Hz, the frame update interval is 8.333 ms (milliseconds). The base station performs scheduling in units of slot length. For example, if the slot length is 1 ms, the base station needs to schedule the PDCCH at intervals of 9 ms or 8 ms. In such a situation, if the PDCCH monitoring process disclosed in Non-Patent Document 1 is used, the UE needs to monitor the PDCCH in all slots every 1 ms in order to detect PDCCHs that may be scheduled at different intervals. This causes a problem of increased power consumption associated with the PDCCH monitoring process in the UE.

Similarly, when performing the PDCCH monitoring process disclosed in Non-Patent Document 2, it is necessary to monitor the PDCCH at specific symbol timings in all slots. This causes a problem of increased processing power associated with the PDCCH monitoring process in the UE.

In view of the above-mentioned problems, one of the objectives of the present disclosure is to provide a communication device, a communication terminal, a communication system, a communication method, and a program that can reduce the burden of PDCCH monitoring processing.

The communication device according to the first aspect of the present disclosure includes a control unit that uses the slot length of a slot constituting a radio frame and the frame rate of data to determine a first period in units of the slot and a second period in units of the symbols constituting the slot, and uses the first period and the second period to determine a symbol number for transmitting scheduling information of the data, and a communication unit that transmits the first period and values related to the second period to a communication terminal.

A communication terminal according to a second aspect of the present disclosure includes a communication unit that receives a first period in units of slots constituting a radio frame and a value associated with a second period in units of symbols constituting the slots, and a control unit that determines a symbol number for receiving scheduling information for data using the first period and the second period determined based on the value associated with the second period, and the communication unit receives the scheduling information at the symbol number.

The communication system according to the third aspect of the present disclosure includes a communication device including a communication unit that determines a first period in units of slots and a second period in units of symbols constituting the slots using the slot length of the slots constituting a radio frame and the frame rate of the data, determines a symbol number for transmitting scheduling information of the data using the first period and the second period, and transmits the first period and a value related to the second period; and a communication terminal that receives the first period and the value related to the second period, determines a symbol number for receiving scheduling information of data using the first period and the second period specified based on the value related to the second period, and receives the scheduling information at the symbol number.

The communication method according to the fourth aspect of the present disclosure is executed in a communication device that uses the slot length of a slot constituting a radio frame and the frame rate of data to determine a first period in units of the slot and a second period in units of the symbols constituting the slot, determines a symbol number for transmitting scheduling information of the data using the first period and the second period, and transmits the first period and a value related to the second period to a communication terminal.

The program according to the fifth aspect of the present disclosure causes a computer to receive a first period in units of slots constituting a radio frame and a value associated with a second period in units of symbols constituting the slot, determine a symbol number for receiving scheduling information for data using the first period and the second period determined based on the value associated with the second period, and receive the scheduling information at the symbol number.

This disclosure makes it possible to provide a communication device, a communication terminal, a communication system, a communication method, and a program that can reduce the burden of PDCCH monitoring processing.

FIG. 1 is a configuration diagram of a communication device according to the present disclosure. FIG. 2 is a diagram showing the configuration of a radio frame according to the present disclosure. FIG. 2 is a configuration diagram of a communication terminal according to the present disclosure. FIG. 2 is a diagram showing a communication process executed in a communication device according to the present disclosure. FIG. 2 is a diagram illustrating a communication process executed in a communication terminal according to the present disclosure. FIG. 1 is a configuration diagram of a communication system according to the present disclosure. A diagram showing the flow of communication processing between a UE and a gNB according to the present disclosure. FIG. 1 is a diagram illustrating a search space according to the present disclosure. FIG. 1 is a diagram illustrating a search space according to the present disclosure. A diagram showing the flow of a search space determination process in a UE according to the present disclosure. FIG. 1 is a diagram illustrating the configuration of a gNB according to the present disclosure. FIG. 1 is a diagram illustrating the configuration of a UE according to the present disclosure.

(Embodiment 1)
An example of the configuration of the communication device 10 will be described below with reference to Fig. 1. The communication device 10 may be a computer device that operates when a processor executes a program stored in a memory. The communication device 10 may be a device disposed in a mobile network, such as a base station or an access network node.

The communication device 10 has a control unit 11 and a communication unit 12. The control unit 11 and the communication unit 12 may be software or a module in which processing is performed by a processor executing a program stored in a memory. Alternatively, the control unit 11 and the communication unit 12 may be hardware such as a circuit or a chip.

The control unit 11 uses the slot length of the slots constituting the radio frame and the frame rate of the data to determine a first period in units of slots and a second period in units of symbols constituting the slots. Furthermore, the control unit 11 uses the first period and the second period to determine a symbol number for transmitting scheduling information for the data.

Here, an example of the configuration of radio frames, slots, and symbols will be described using FIG. 2. Because FIG. 2 is an example, the configuration of radio frames, slots, and symbols is not limited to the configuration shown in FIG. 2, and various configurations are possible.

Figure 2 shows that one radio frame is 10 ms. Furthermore, one radio frame is composed of 10 subframes. Furthermore, Figure 2 shows that one subframe corresponds to one slot or two slots. NR adopts OFDM (Orthogonal Frequency Division Multiplexing) like LTE (Long Term Evolution). Furthermore, NR supports 15 kHz, which is the same subcarrier spacing as LTE, and also supports 30 kHz, 60 kHz, 120 kHz, and 240 kHz. Here, when the subcarrier spacing is 15 kHz, one subframe corresponds to one slot, and when the subcarrier spacing is 30 kHz, one subframe corresponds to two slots. Furthermore, when the subcarrier spacing is 60 kHz, one subframe corresponds to four slots, when the subcarrier spacing is 120 kHz, one subframe corresponds to eight slots, and when the subcarrier spacing is 240 kHz, one subframe corresponds to 16 slots.

Furthermore, FIG. 2 shows that one slot is composed of 14 symbols, regardless of the subcarrier spacing. Alternatively, one slot may be composed of 12 symbols. Here, the symbols may be OFDM symbols.

Returning to FIG. 1, the frame rate of the data used to determine the first period and the second period may be, for example, the frame rate of images used in AR (Augmented Reality) or VR (Virtual Reality). The frame rates of these images may be, for example, 60Hz, 120Hz, 144Hz, etc. 60Hz, 120Hz, and 144Hz have the same meaning as 60fps (flame per second), 120fps, and 144fps. When the frame rates are 60Hz, 120Hz, and 144Hz, the frame (or data) update intervals are 16.666ms, 8.333ms, and 6.944ms.

The first period is expressed in units of slot length, and may be expressed as an integer multiple of 1 ms, for example. The second period is expressed in units of symbol length, and may be expressed as an integer multiple of 1 ms/14 ("/" indicates division). The first period is a longer value than the second period.

The symbol number may be determined, for example, using a serial number within the first period, or may be determined, for example, as the bth symbol in the ath slot (where a and b are integers equal to or greater than 1). The data may be, for example, video data, or may be U (User)-Plane data transmitted in, for example, a PDSCH (Physical Downlink Shared Channel) or a PUSCH (Physical Uplink Shared Channel). In addition, the scheduling information may be referred to as C (Control)-Plane data transmitted by the PDCCH. The scheduling information corresponds to DCI transmitted by the PDCCH.

The communication unit 12 transmits the first period and a value related to the second period to the communication terminal. The value related to the second period may be a value indicating the second period, or may be a value used to calculate the second period. For example, the value related to the second period may be a value indicating the number of times a symbol-unit period is repeated within the first period. Alternatively, the value related to the second period may be a value indicating the ratio of the second period to the first period.

Next, an example configuration of the communication terminal 20 will be described with reference to FIG. 3. The communication terminal 20 may be a computer device that operates by a processor executing a program stored in a memory. The communication terminal 20 may be, for example, a device that performs wireless communication with the communication device 10. The communication terminal 20 may be a mobile phone terminal, a smartphone terminal, a wearable device/HMD (Head Mounted Display), an IoT (Internet of Things) terminal, an MTC (Machine Type Communication) terminal, digital signage, etc. The communication terminal 20 may also be a UE, which is used as a general term for terminals in 3GPP.

The communication terminal 20 has a communication unit 21 and a control unit 22. The communication unit 21 and the control unit 22 may be software or modules that perform processing by a processor executing a program stored in a memory.

The communication unit 21 receives a first period, the unit being the slot that constitutes the radio frame, and a value related to a second period, the unit being the symbol that constitutes the slot. The communication unit 21 receives the first period and the value related to the second period by wireless communication.

The control unit 22 determines a symbol number for receiving data scheduling information using the first period and the second period identified based on a value related to the second period. When the communication unit 21 receives a value indicating the second period as a value related to the second period, the control unit 22 identifies the received value as the second period. When the communication unit 21 receives a value used to calculate the second period as a value related to the second period, the control unit 22 calculates the second period based on the received value.

The control unit 22 uses the first period and the second period to determine the symbol number for receiving the data scheduling information.

The communication unit 21 receives the scheduling information set to the symbol number determined by the control unit 22. Receiving the scheduling information may be rephrased as detecting the scheduling information. By receiving the scheduling information, the communication terminal 20 identifies the resources allocated to the data and enables reception of the data.

Next, the flow of communication processing executed in the communication device 10 will be described with reference to FIG. 4. First, the control unit 11 determines a first period in units of slots and a second period in units of symbols constituting the slots, using the slot length of the slots constituting the radio frame and the frame rate of the data (S11).

Next, the control unit 11 uses the first period and the second period to determine a symbol number for transmitting the scheduling information of the data (S12). Next, the communication unit 12 transmits the first period and a value related to the second period to the communication terminal (S13).

Next, the flow of communication processing executed in the communication terminal 20 will be described with reference to FIG. 5. First, the communication unit 21 receives a value related to a first period in units of slots constituting a radio frame and a second period in units of symbols constituting a slot (S21).

Next, the control unit 22 determines a symbol number for receiving the scheduling information of the data using the first period and the second period identified based on a value related to the second period (S22). Next, the communication unit 21 receives the scheduling information at the symbol number determined by the control unit 22 (S23).

As described above, the communication device 10 determines a first period in units of slots and a second period in units of symbols. Furthermore, the communication terminal 20 identifies the first period and the second period using the first period and a value related to the second period. As a result, the communication terminal 20 can execute processing for receiving scheduling information at the timing indicated in the second period in units of symbols, and therefore does not need to monitor all slots to receive scheduling information. As a result, the burden of monitoring the scheduling information on the communication terminal 20 can be reduced.

(Embodiment 2)
Next, a configuration example of a communication system will be described with reference to Fig. 6. The UE 30 corresponds to the communication terminal 20 in Fig. 3. The gNB 40 corresponds to the communication device 10 in Fig. 1. The UE 30 and the gNB 40 support a communication method defined as 5G or NR in 3GPP.

Here, we will explain the scheduling of PDCCH in communication between UE 30 and gNB 40. UE 30 monitors a set of PDCCH candidates in one or more CORESETs (Control resource sets) of the active DL BWP. A CORESET is a resource element that transmits PDCCH and is defined by frequency and symbol. An active DL BWP indicates a BWP in an activated serving cell. UE 30 monitors the search space, receives PDCCH candidates, and further decodes DCI.

The set of PDCCH candidates monitored by UE 30 is defined in a PDCCH search space set. The PDCCH search space set may be referred to as a search space set or a search space. A CSS (Common Search Space) set or a USS (UE-specific Search Space) set is defined as a search space set. UE 30 monitors PDCCH candidates in a search space set determined according to the type of PDCCH. The search space set determined according to the type of PDCCH may be, for example, Type 0-PDCCH CSS, Type 0A-PDCCH CSS, Type 0B-PDCCH CSS, Type 1-PDCCH CSS, Type 1A-PDCCH CSS, Type 2-PDCCH CSS, or Type 3-PDCCH CSS. Each Type differs depending on the use of the PDCCH. For example, Type 0 may be used to decode SIB (System Information Block) 1, and Type 0A may be used to decode SIBs other than SIB1.

Here, the timing of the PDCCH monitored by UE 30 may be determined by the following equation 1.

The UE 30 determines whether the frame number n _f satisfies the formula 1.

Starting from slot k s −T s, the UE 30 monitors the PDCCH of the search space set, with a predetermined number of slots, T _s , as the search space set. In other words, the UE 30 does not need to monitor the PDCCH in the slot determined by k _s −T _s .

Furthermore, Equation 1 is used to calculate a search space set on a slot basis, but the following Equation 2 may also be used to calculate a search space set on a symbol basis.

The period k _s in slot units corresponds to the first period.

corresponds to the second period, which is a period in symbol units. Here, a method of calculating k _s and k _factor used in Equation 2 will be described. In the following description, an example will be described in which the slot length is 1 ms, the frame rate is 120 Hz, and the frame update interval (update period) is 8.333 ms. Here, the frame rate may be notified from a higher layer, such as Layer 2 or higher, to the control unit 11 that executes control of Layer 1 (physical layer). In addition, the gNB 40 may receive the frame rate, for example, from a core network node. Alternatively, the gNB 40 may learn or estimate the frame rate from the arrival interval of data packets.

The control unit 11 calculates k _s and k _factor by dividing the number of slots per second by the frame rate of the data, and further dividing the numerator and denominator by the greatest common divisor of the numerator and denominator values.

Specifically, k _s ×k _factor = 1000 (slot)/120 (frame) = 25/3. In this case, k _s = 25 slots and k _factor = 1/3 are specified. Alternatively, if k _s × (1/k _factor ) = 25/3, k _factor = 3 may be used. In the following description, k _s ×k _factor = 25/3 is used.

If the number of symbols per slot is 14, the period per symbol is 117, as shown below.

Also, the period 117 symbol is 8.357 ms. That is, when the offset in symbol units is 0 symbol, the control unit 11 of the gNB 40 corresponding to the communication device 10 sets the PDCCH to the symbol #0, the symbol #117, and the symbol #234 based on the symbol #0 at the beginning of the period k _s . Also, the control unit 22 of the UE 30 monitors the PDCCH with the symbol #0, the symbol #117, and the symbol #234 at the beginning and the section of the length T _s symbols as the search space set. #0, #117, and #234 indicate symbol numbers that identify the 25×14=350 symbols included in the period k _s . Symbols #0 to #349 are specified in the period k _s .

As a result, the period of transmission opportunities for PDCCH transmitted from gNB 40 to UE 30 will be 117 symbols from symbol #0 to symbol #116, 117 symbols from symbol #117 to symbol #233, and 116 symbols from symbol #234 to symbol #349.

117 symbols is 8.357 ms, 116 symbols is 8.286 ms, and in a period k _s , it is possible to schedule the PDCCH every 8.33 ms on average.

As a result, the gNB 40 can schedule the PDCCH at approximately the same timing as the frame update interval of 8.333 ms when the frame rate is 120 Hz. In addition, the UE 30 can also detect the PDCCH every 8.33 ms on average in the period k _s , so that jitter occurring in the wireless section can be suppressed. If the UE 30 monitors a search space set that is determined with a predetermined position as the start position in all slots, the base station also needs to set the PDCCH at a position that matches the search space. Therefore, it takes time from when the data is updated until the data is scheduled, so that jitter or delay occurs between the timing of data generation and the timing of data transmission.

Here, since the PDCCH is set at symbol #0 in the cycle k _s , the cycle (or interval) starting from symbol #234 is 116 symbols instead of 117 symbols. That is, by combining 117 symbols defined as a cycle in symbol units with a cycle in slot units, the start position of the symbol in which the PDCCH is set in the cycle k _s can be fixed to #0. If only 117 symbols defined as a cycle in symbol units were used, the start position of the symbol in which the PDCCH is set in the cycle k _s would shift from #1 to #2. In this case, the timing of data generation according to the frame rate and the symbol position for setting the PDCCH shift, and jitter occurs in the data transmitted between the UE 30 and the gNB 40. That is, by combining 117 symbols defined as a cycle in symbol units with a cycle in slot units, it is possible to prevent jitter from occurring or increasing in the data transmitted between the UE 30 and the gNB 40.

The communication unit 12 of the gNB 40 transmits the values of k _s and k _factor to the UE 30. Alternatively, the communication unit 12 may transmit the values of k _s and the period in symbol units to the UE 30.

　So far, we have explained an example where the slot length is 1 ms, the frame rate is 120 Hz, and the frame update interval (update cycle) is 8.333 ms, but here we will explain another example. Specifically, we will explain the case where the slot length is 0.5 ms, the frame rate is 144 Hz, and the frame update cycle is 6.944 ms.

In this case, k _s is 125 slots, and k _factor is 1/9. Furthermore, if the number of symbols per slot is 14 symbols, the period per symbol is 195 symbols (6.96 ms). Furthermore, the gNB 40 sets the PDCCH to symbol #0, symbol #195, symbol #390, symbol #585, symbol #780, symbol #975, symbol #1170, symbol #1365, and symbol #1560, based on the first symbol #0 of _the period k s. Furthermore, the control unit 22 of the UE 30 monitors the PDCCH, using a section of length T _s symbols as a search space set, starting from symbol #0, symbol #195, symbol #390, symbol #585, symbol #780, symbol #975, symbol #1170, symbol #1365, and symbol #1560.

In addition, the period of transmission opportunities for PDCCH transmitted from gNB 40 to UE 30 is 195 symbols when starting with symbol #0, symbol #195, symbol #390, symbol #585, symbol #780, symbol #975, symbol #1170, and symbol #1365. On the other hand, when starting with symbol #1560, the period is 190 symbols.

Here, the flow of communication processing between the UE 30 and the gNB 40 will be described with reference to Fig. 7. First, the gNB 40 calculates the values of the period k _s and k _factor using the slot length and the frame rate of the data (S31). Next, the gNB 40 transmits the values of the period k _s and k _factor to the UE 30 (S32). At this time, the gNB 40 may also transmit to the UE 30 the start slot of the period k _s (slot-unit offset), the OFDM symbol-unit offset, and T _symb .

For example, the gNB 40 may transmit the period k _s and the k _factor to the UE 30 using higher layer signaling. The higher layer signaling may be, for example, a signaling message transmitted to the UE 30 in a medium access control (MAC) layer or a layer higher than the MAC layer, for example, an RRC message. The gNB 40 may set the period k _s and the k _factor in an RRC information element set in the RRC message and transmit it to the UE 30. The RRC information element may be, for example, a Search Space information element set in the RRC message. More specifically, the period k _s and the k _factor may be set in monitoringSlotPeriodicityAndOffset or other parameters included in the Search Space information element. The RRC message may be a message directed to a specific UE, or may be system information directed to all UEs.

Alternatively, the gNB 40 may transmit a PBCH (Physical Broadcast Channel) including an MIB including the period k _s and the k _factor to the UE 30. Alternatively, the gNB 40 may transmit a RACH response including the period k _s and the k _factor to the UE 30 upon receiving a RACH preamble from the UE 30.

The starting slot (slot offset) of the period k _s , the OFDM symbol offset, and T _symb may be transmitted to the UE 30 along with the period k _s and the k _factor , or the starting slot (slot offset) of the period k _s , the OFDM symbol offset, and T _symb may be transmitted to the UE 30 using a message, channel, or parameter different from the period k _s and the k _factor .

Furthermore, when the UE 30 transmits uplink data, the UE 30 recognizes the generation timing or transmission timing of the data. Therefore, the UE 30 may notify the gNB 40 of the desired start slot (slot-based offset) of the period k _s and the OFDM symbol-based offset in accordance with the generation timing or transmission timing of the data. For example, the UE 30 may transmit the desired slot-based offset and OFDM symbol-based offset to the gNB 40 using a MAC CE (Control Element).

The gNB 40 may update or reconfigure the BWP using the information regarding the offset received from the UE 30. Alternatively, the gNB 40 may apply the offset desired by the UE 30 by performing BWP Switching or Search Space Set Switching (SSSG) to switch to a search space in which the offset desired by the UE 30 is set. The gNB 40 may transmit information regarding the updated offset in step S32.

Next, the control unit 22 of the UE 30 specifies the search space by applying the information received from the gNB 40 to Equation 2 (S33).

Furthermore, the area between the start position of the search space and T _symb , which indicates the number of symbols of the PDCCH reception opportunity, is specified as the search space. When specifying the start position of the search space, the frame number and slot number including the start position of the search space are also specified.

Next, the control unit 22 of the UE 30 monitors the PDCCH in the identified search space (S34). Here, the search space monitored by the UE 30 is explained using FIG. 8.

FIG. 8 shows that the frame number n _f includes multiple slots. Also, the slot number of the search space specified using Equation 2 is

and the symbol at the beginning of the search space is

In FIG. 8, it is shown that the offset in OFDM symbol units is 3 symbols, and T _symb is 3 symbols.

As described above, the gNB 40 calculates the period k _s and the k _factor by using the slot length and the frame rate of the data. The gNB 40 determines the symbol position for transmitting the PDCCH using the period k _s and the k _factor . The UE 30 specifies the search space for monitoring the PDCCH using the period k _s and the k _factor .

The slot-based period and symbol-based period determined using the slot length and frame rate are closer to the data update period determined based on the frame rate. This makes it possible to reduce jitter in the data transmitted between the UE 30 and the gNB 40. Specifically, it is possible to reduce the delay between the data update period and the data transmission period.

Furthermore, if only the symbol-based period is defined, the data update period and the symbol-based period will deviate from each other, and data jitter will increase. On the other hand, in the second embodiment, the slot-based period and the symbol-based period are used to determine the symbol position for transmitting the PDCCH and to specify the search space. As a result, the deviation between the data update period and the symbol-based period is corrected for each slot-based period k _s , and therefore data jitter can be prevented from increasing.

(Embodiment 3)
Next, the search space monitored by UE 30 will be described with reference to Fig. 9. In Fig. 9, a predetermined T _symb is set as the search space from the symbol at the start position of the search space, as in Fig. 8. Fig. 9 shows that UE 30 attempts to detect DCI in the symbol specified in monitoringSymbolsWithinSlot.

The monitoringSymbolsWithinSlot is a parameter included in the Search Space information element of the RRC message. In FIG. 9, the monitoringSymbolsWithinSlot indicates that the position of the shaded symbol is set to "1". In FIG. 9, the monitoringSymbolsWithinSlot indicates that one symbol that the UE does not attempt to detect is sandwiched between the symbols that the UE attempts to detect. For example, an example is shown in which the monitoringSymbolsWithinSlot indicating a 14-bit bitmap is set to "10101010101010". That is, the UE 30 attempts to detect DCI in the symbol indicated by the position where the monitoringSymbolsWithinSlot is set to 1 within the period determined by the start position of the search space and T _symb .

The DCI detection location described in Fig. 9 is three symbols, similar to the DCI detection location described in Fig. 8, so the power consumption is substantially similar compared to the search space monitoring process in Fig. 8. However, T _symb in Fig. 9 is longer than T _symb in Fig. 8. Therefore, when the search space monitoring process in Fig. 9 is executed, the resistance to jitter occurring in the radio section between the UE 30 and the gNB 40 is stronger compared to the case where the search space monitoring process in Fig. 8 is executed.

(Embodiment 4)
Next, a process of determining a search space in the UE 30 will be described with reference to Fig. 10. When determining the monitoring timing of the PDCCH, the UE 30 may select whether to determine a search space in units of slots using Equation 1 or to determine a search space in units of symbols using Equation 2. Fig. 10 shows a process of determining a search space by the UE 30 selecting whether to determine a search space in units of slots or a search space in units of symbols.

First, the communication unit 21 of the UE 30 receives control information required to monitor the PDCCH from the gNB 40 (S41). The control information required to monitor the PDCCH may include, for example, a period k _s and a k _factor , and may further include a start slot (offset in slot units) of the period k _s , an offset in OFDM symbol units, T _s , T _symb , and the like.

Next, the control unit 22 of the UE 30 judges whether or not the period k _s and the k _factor are included in the control information (S42). Alternatively, the control unit 22 may judge whether or not the k _factor is included in the control information. If the control unit 22 judges that the k _factor is not included in the control information, the control unit 22 uses Equation 1 to calculate the slot number in the radio frame,

In addition, when the control unit 22 determines that the control information includes the period k _s and k _factor or the k _factor , it calculates the symbol number k s using Equation 2 to determine the search space in units of symbols.

is determined (S44).

In this way, the UE 30 determines the search space in units of slots or the search space in units of symbols depending on whether the control information includes the period k _s and the k _factor , or whether the control information includes the k _factor . This allows the UE 30 to reliably extract the PDCCH.

As a variation of this embodiment, gNB40 may include, in the control information transmitted to UE30 in S41, identification information that explicitly indicates whether the search space should be a slot-based search space using Equation 1 or a symbol-based search space using Equation 2. The identification information may be, for example, 1 bit (0 or 1) information. In this case, 0 may indicate a slot-based search

space using Equation

1, and 1 may indicate a symbol-based search space using Equation 2.

In this case, in S42, UE 30 may select whether to determine a slot-based search space using Equation 1 or to determine a symbol-based search space using Equation 2 based on the identification information included in the control information.

(Other embodiments)
In the second embodiment, as another example of the formula 2 used to calculate the frame number, slot number, and symbol number indicating the start position of the search space, the following formula 3 may be used.

Alternatively, as another example of Equation 2, the following Equation 4 may be used.

Furthermore, the k _factor described in the second embodiment may be expressed using multiple parameters as shown below.

k _factor = k _{factor_0} × k _{factor_1} × ... k _{factor_n-1}

The k _{factor_n-1} may be set to a value such as 1/2, 1/3, or 1/5, for example.

Furthermore, the period k _s may be expressed using multiple parameters, as shown below.

k _s = k _{s_0} × k _{s_1} ×・・・ k _{s_m-1}

k _{s_m-1} may be set to values such as 1, 2, 3, and 5.

In this way, by defining k _factor or k _s using multiple parameters, for example, by combining parameters, it becomes possible to define k _factor or k _s . In other words, k _factor or k _s of any value can be defined using predetermined parameters.

FIG. 11 is a block diagram showing an example of the configuration of a communication device 10 and a gNB 40 (hereinafter, referred to as the communication device 10, etc.). Referring to FIG. 11, the communication device 10, etc. includes an RF transceiver 1001, a network interface 1003, a processor 1004, and a memory 1005. The RF transceiver 1001 performs analog RF signal processing to communicate with UEs. The RF transceiver 1001 may include multiple transceivers. The RF transceiver 1001 is coupled to an antenna 1002 and a processor 1004. The RF transceiver 1001 receives modulation symbol data (or OFDM symbol data) from the processor 1004, generates a transmission RF signal, and supplies the transmission RF signal to the antenna 1002. The RF transceiver 1001 also generates a baseband reception signal based on the reception RF signal received by the antenna 1002, and supplies the baseband reception signal to the processor 1004.

The network interface 1003 is used to communicate with network nodes (e.g., other core network nodes). The network interface 1003 may include, for example, an IEEE 802.3 series compliant network interface card (NIC).

Processor 1004 performs data plane processing and control plane processing, including digital baseband signal processing for wireless communication.

The processor 1004 may include multiple processors. For example, the processor 1004 may include a modem processor (e.g., DSP) that performs digital baseband signal processing, and a protocol stack processor (e.g., CPU or MPU) that performs control plane processing.

The memory 1005 is composed of a combination of volatile and non-volatile memory. The memory 1005 may include multiple physically independent memory devices. The volatile memory is, for example, Static Random Access Memory (SRAM) or Dynamic RAM (DRAM), or a combination of these. The non-volatile memory is Mask Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, a Solid state drive (SSD), or a hard disk drive, or any combination of these. The memory 1005 may include storage located remotely from the processor 1004. In this case, the processor 1004 may access the memory 1005 via the network interface 1003 or an I/O interface not shown.

The memory 1005 may store a software module (computer program) including instructions and data for performing processing by the communication device 10, etc., described in the above-described embodiments. In some implementations, the processor 1004 may be configured to read the software module from the memory 105 and execute it to perform processing by the base station 10, etc., described in the above-described embodiments.

FIG. 12 is a block diagram showing an example of the configuration of a communication terminal 20 and a UE 30 (hereinafter referred to as communication terminal 20, etc.). A radio frequency (RF) transceiver 1101 performs analog RF signal processing to communicate with a communication device 10 or a gNB 40. The analog RF signal processing performed by the RF transceiver 1101 includes frequency up-conversion, frequency down-conversion, and amplification. The RF transceiver 1101 is coupled to an antenna 1102 and a baseband processor 1103. That is, the RF transceiver 1101 receives modulation symbol data (or OFDM symbol data) from the baseband processor 1103, generates a transmission RF signal, and supplies the transmission RF signal to the antenna 1102. The RF transceiver 1101 also generates a baseband reception signal based on the reception RF signal received by the antenna 1102, and supplies this to the baseband processor 1103.

The baseband processor 1103 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Digital baseband signal processing includes (a) data compression/decompression, (b) data segmentation/concatenation, (c) generation/decomposition of transmission formats (transmission frames), (d) transmission path encoding/decoding, (e) modulation (symbol mapping)/demodulation, and (f) generation of OFDM symbol data (baseband OFDM signal) using Inverse Fast Fourier Transform (IFFT). Meanwhile, control plane processing includes communication management for

layers

1, 2, and 3.

The baseband processor 1103 may include a modem processor (e.g., Digital Signal Processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., Central Processing Unit (CPU) or Micro Processing Unit (MPU)) that performs control plane processing. In this case, the protocol stack processor that performs control plane processing may be shared with the application processor 1104 described below.

The application processor 1104 is also called a CPU, MPU, microprocessor, or processor core. The application processor 1104 may include multiple processors (multiple processor cores). The application processor 1104 executes a system software program (Operating System (OS)) and various application programs (e.g., a calling application, a web browser, a mailer, a camera operation application, a music playback application) read from the memory 1106 or a memory not shown, thereby realizing various functions of the communication terminal 20, etc.

In some implementations, the baseband processor 1103 and the application processor 1104 may be integrated on a single chip, as shown by the dashed line (1105) in 11. In other words, the baseband processor 1103 and the application processor 1104 may be implemented as a single System on Chip (SoC) device 1105. An SoC device is sometimes called a system Large Scale Integration (LSI) or chipset.

The memory 1106 is a volatile memory or a non-volatile memory or a combination thereof. The memory 1106 may include multiple physically independent memory devices. The volatile memory is, for example, a Static Random Access Memory (SRAM) or a Dynamic RAM (DRAM) or a combination thereof. The non-volatile memory is a mask Read Only Memory (MROM), an Electrically Erasable Programmable ROM (EEPROM), a flash memory, a Solid state drive (SSD), or a hard disk drive, or any combination thereof. For example, the memory 1106 may include an external memory device accessible from the baseband processor 1103, the application processor 1104, and the SoC 1105. The memory 1106 may include an internal memory device integrated within the baseband processor 1103, the application processor 1104, or the SoC 1105. Additionally, memory 1106 may include memory within a Universal Integrated Circuit Card (UICC).

The memory 1106 may store a software module (computer program) including instructions and data for performing processing by the communication terminal 20, etc., described in the above-mentioned embodiments. In some implementations, the baseband processor 1103 or the application processor 1104 may be configured to read the software module from the memory 1106 and execute it to perform processing by the communication terminal 20, etc., described in the above-mentioned embodiments.

In the above examples, the program includes instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. The program may be stored on a non-transitory computer-readable medium or tangible storage medium. By way of example and not limitation, computer-readable medium or tangible storage medium may include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray® disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable medium or communication medium may include electrical, optical, acoustic, or other forms of propagated signals.

The present disclosure has been described above with reference to the embodiments, but the present disclosure is not limited to the above-mentioned embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

The drawings are merely examples for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but also to one or more other embodiments. As will be appreciated by those skilled in the art, various features or steps described with reference to any one drawing may be combined with features or steps shown in one or more other figures to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessarily required to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

A part or all of the above-described embodiments can be described as, but is not limited to, the following supplementary notes.
(Appendix 1)
a control unit that determines a first period in units of slots and a second period in units of symbols constituting the slots, using a slot length of the slots constituting a radio frame and a frame rate of data, and determines a symbol number for transmitting scheduling information of the data, using the first period and the second period;
A communication device comprising: a communication unit that transmits the first period and a value related to the second period to a communication terminal.
(Appendix 2)
The control unit is
2. The communications device of claim 1, further comprising: determining the first period and a value associated with the second period by dividing the number of slots included in the radio frame of a predetermined period by the value of the frame rate.
(Appendix 3)
The control unit is
The communication device described in Supplementary Note 2, wherein a value obtained by dividing the number of slots by the value of the frame rate is k _s ×k _factor , k _s indicating a numerator value is the first period, and the value of k _factor is a value related to the second period.
(Appendix 4)
The communication unit is
The communication device according to

claim

2 or 3, wherein the k _s and the k _factor are transmitted to a communication terminal that is a destination of the data.
(Appendix 5)
The control unit is
5. A communication device according to any one of claims 2 to 4, wherein the second period is a value obtained by multiplying a value obtained by dividing the number of slots by the value of the frame rate by the number of symbols constituting a slot.
(Appendix 6)
The control unit is
The first period and the second period,

6. The communication device according to claim 1, wherein the symbol number is determined by applying the above to the communication device.
(Appendix 7)
The control unit is
The first period and the second period,

6. The communication device according to claim 1, wherein the symbol number is determined by applying the above to the communication device.
(Appendix 8)
The control unit is
The first period and the second period,

6. The communication device according to claim 1, wherein the symbol number is determined by applying the above to the communication device.
(Appendix 9)
a communication unit that receives a value related to a first period in units of slots that constitute a radio frame and a value related to a second period in units of symbols that constitute the slot;
a control unit that determines a symbol number for receiving scheduling information of data using the first period and a second period identified based on a value related to the second period;
The communication unit is
A communications terminal that receives the scheduling information at the symbol number.
(Appendix 10)
The control unit is
10. The communications terminal of claim 9, further comprising: determining whether or not a value associated with the second period has been received; and determining the symbol number if a value associated with the second period has been received.
(Appendix 11)
a communication unit that determines a first period in units of slots and a second period in units of symbols constituting the slots, using a slot length of a slot constituting a radio frame and a frame rate of data, determines a symbol number for transmitting scheduling information of the data, using the first period and the second period, and transmits a value related to the first period and the second period;
a communications terminal that receives the first period and a value associated with the second period, determines a symbol number for receiving scheduling information for data using the first period and the second period identified based on the value associated with the second period, and receives the scheduling information at the symbol number.
(Appendix 12)
The communication device includes:
12. The communication system of claim 11, wherein the first period and a value associated with the second period are determined by dividing the number of slots included in the radio frame of a predetermined period by the value of the frame rate.
(Appendix 13)
determining a first period in units of slots and a second period in units of symbols constituting the slots, using a slot length of the slots constituting the radio frame and a frame rate of data;
determining a symbol number for transmitting scheduling information of the data using the first period and the second period;
A communication method performed in a communication device, transmitting said first period and a value related to said second period to a communication terminal.
(Appendix 14)
When determining the first period and the second period,
14. The communication method of claim 13, wherein the first period and a value associated with the second period are determined by dividing a number of slots included in the radio frame of a predetermined period by the value of the frame rate.
(Appendix 15)
When determining the first period and the second period,
15. The communication method of claim 14, wherein a value obtained by dividing the number of slots by the value of the frame rate is k _s ×k _factor , k _s representing a numerator value is the first period, and the value of k _factor is a value related to the second period.
(Appendix 16)
when transmitting the first period and a value related to the second period to the communication terminal,
16. The communication method according to claim 14, further comprising transmitting the k _s and the k _factor to a communication terminal that is a destination of the data.
(Appendix 17)
When determining the first period and the second period,
16. The communication method according to claim 14, wherein the second period is a value obtained by multiplying a value obtained by dividing the number of slots by the value of the frame rate by the number of symbols constituting a slot.
(Appendix 18)
receiving a value related to a first period in units of slots constituting a radio frame and a value related to a second period in units of symbols constituting the slot;
determining a symbol number for receiving scheduling information for data using the first period and a second period identified based on a value associated with the second period;
A communications method performed in a communications terminal, the communications terminal receiving the scheduling information at the symbol number.
(Appendix 19)
determining a first period in units of slots and a second period in units of symbols constituting the slots, using a slot length of the slots constituting the radio frame and a frame rate of data;
determining a symbol number for transmitting scheduling information of the data using the first period and the second period;
A program that causes a computer to execute the following: transmitting the first period and a value related to the second period to a communication terminal.
(Appendix 20)
receiving a value related to a first period in units of slots constituting a radio frame and a value related to a second period in units of symbols constituting the slot;
determining a symbol number for receiving scheduling information for data using the first period and a second period identified based on a value associated with the second period;
receiving the scheduling information at the symbol number.

Some or all of the elements (e.g., configurations and functions) described in Appendix 2 to Appendix 8 that are dependent on Appendix 1 may also be dependent on

Appendix

11, 13, and 19 in a similar dependent relationship to Appendix 2 to Appendix 8. Also, some or all of the elements (e.g., configurations and functions) described in Appendix 10 that are dependent on Appendix 9 may also be dependent on

Appendix

11, 18, and 20 in a similar dependent relationship to Appendix 10. Some or all of the elements described in any appendix may be applied to various hardware, software, recording means for recording software, systems, and methods.

This application claims priority based on Japanese Patent Application No. 2022-171841, filed on October 26, 2022, the entire disclosure of which is incorporated herein by reference.

REFERENCE SIGNS LIST 10 Communication device 11 Control unit 12 Communication unit 20 Communication terminal 21 Communication unit 22 Control unit 30 UE
40 gNB

Claims

a control means for determining a first period in units of slots and a second period in units of symbols constituting the slots, using a slot length of the slots constituting a radio frame and a frame rate of data, and for determining a symbol number for transmitting scheduling information of the data, using the first period and the second period;
A communication device comprising: a communication means for transmitting the first period and a value related to the second period to a communication terminal.
The control means
2. The communication device of claim 1, wherein the first period and the value associated with the second period are determined by dividing a number of slots included in the radio frame of a predetermined period by a value of the frame rate.
The control means
3. The communication device according to claim 2, wherein a value obtained by dividing the number of slots by the value of the frame rate is k s ×k factor , where k s representing a numerator value is the first period, and the value of k factor is a value related to the second period.
The communication means includes:
The communication device according to claim 3 , further comprising: a communication terminal that transmits the k s and the k factor to a destination of the data.
The control means
4. The communication device according to claim 2, wherein the second period is a value obtained by multiplying a value obtained by dividing the number of slots by the value of the frame rate by the number of symbols constituting the slot.
The control means
The first period and the second period,

4. The communication device according to claim 1, wherein the symbol number is determined by applying a coefficient to the symbol number.
The control means
The first period and the second period,

4. The communication device according to claim 1, wherein the symbol number is determined by applying a coefficient to the symbol number.
The control means
The first period and the second period,

4. The communication device according to claim 1, wherein the symbol number is determined by applying a coefficient to the symbol number.
A communication means for receiving a value related to a first period in units of slots constituting a radio frame and a second period in units of symbols constituting the slot;
and control means for determining a symbol number for receiving scheduling information for data using the first period and a second period determined based on a value associated with the second period;
The communication means includes:
A communications terminal that receives the scheduling information at the symbol number.
The control means
The communications terminal according to claim 9 , further comprising: determining whether or not a value associated with the second period has been received; and determining the symbol number if the value associated with the second period has been received.
a communication device comprising: a communication means for determining a first period in units of slots and a second period in units of symbols constituting the slots, using a slot length of a slot constituting a radio frame and a frame rate of data, determining a symbol number for transmitting scheduling information of the data, using the first period and the second period, and transmitting a value related to the first period and the second period;
a communications terminal that receives the first period and a value associated with the second period, determines a symbol number for receiving scheduling information for data using the first period and the second period identified based on the value associated with the second period, and receives the scheduling information at the symbol number.
The communication device includes:
12. The communication system of claim 11, wherein the first period and the value associated with the second period are determined by dividing a number of slots included in the radio frame of a predetermined duration by a value of the frame rate.
determining a first period in units of slots and a second period in units of symbols constituting the slots, using a slot length of the slots constituting the radio frame and a frame rate of data;
determining a symbol number for transmitting scheduling information of the data using the first period and the second period;
A communication method performed in a communication device, transmitting said first period and a value related to said second period to a communication terminal.
When determining the first period and the second period,
14. The method of claim 13, further comprising: determining the first period and a value associated with the second period by dividing a number of slots included in the radio frame of a predetermined duration by a value of the frame rate.
When determining the first period and the second period,
15. The communication method of claim 14, wherein a value obtained by dividing the number of slots by the value of the frame rate is k s ×k factor , where k s representing a numerator value is the first period, and the value of k factor is a value related to the second period.
when transmitting the first period and a value related to the second period to the communication terminal,
The communication method according to claim 15 , further comprising transmitting the k s and the k factor to a communication terminal to which the data is to be transmitted.
When determining the first period and the second period,
The communication method according to claim 14 or 15, wherein the second period is a value obtained by multiplying a value obtained by dividing the number of slots by the value of the frame rate by the number of symbols constituting a slot.
receiving a value related to a first period in units of slots constituting a radio frame and a value related to a second period in units of symbols constituting the slot;
determining a symbol number for receiving scheduling information for data using the first period and a second period identified based on a value associated with the second period;
A communications method performed in a communications terminal, the communications terminal receiving the scheduling information at the symbol number.
determining a first period in units of slots and a second period in units of symbols constituting the slots, using a slot length of the slots constituting the radio frame and a frame rate of data;
determining a symbol number for transmitting scheduling information of the data using the first period and the second period;
A program that causes a computer to execute the steps of: transmitting the first period and a value related to the second period to a communication terminal.
receiving a value related to a first period in units of slots constituting a radio frame and a value related to a second period in units of symbols constituting the slot;
determining a symbol number for receiving scheduling information for data using the first period and a second period identified based on a value associated with the second period;
receiving the scheduling information at the symbol number.