Method and apparatus for transmitting data and control signal in cellular network based on dynamic time division duplex

Abstract

A communication method performed by a first communication node in a communication system is disclosed. The method includes the steps of scheduling a slot p, whose transmission direction is not determined, for downlink transmission; determining the transmission direction of a time slot included in the slot p; if the transmission direction of the time slot is uplink, scheduling a slot p+n after the slot p for uplink transmission; and switching the state of the slot p+n-1 to an SG state, wherein the slot p+n-1 in the SG state is a time interval required for switching between downlink transmission and uplink transmission, and p and n are each natural numbers.

Description

Technology Field

[0001] The present invention relates to time division redundancy technology, and more specifically, to data and control message transmission technology in a cellular network based on dynamic time division redundancy in a mobile communication system. Background Technology

[0002] Along with the advancement of information and communication technology, various wireless communication technologies are being developed. Representative wireless communication technologies include LTE (long term evolution) and NR (new radio), which are defined in the 3GPP (3rd generation partnership project) standards. LTE can be one of the wireless communication technologies among 4G (4th Generation) wireless communication technologies, and NR can be one of the wireless communication technologies among 5G (5th Generation) wireless communication technologies.

[0003] To handle the surge in wireless data following the commercialization of 4G communication systems (e.g., communication systems supporting LTE), 5G communication systems (e.g., communication systems supporting NR) that use frequency bands higher than those of 4G communication systems (e.g., frequency bands below 6 GHz) are being considered. 5G communication systems can support eMBB (enhanced Mobile BroadBand), URLLC (Ultra-Reliable and Low Latency Communication), and mMTC (massive Machine Type Communication).

[0004] LTE TDD (time division duplex) based systems may have each frame composed of 10 subframes, and each subframe may consist of a DL (downlink), UL (uplink), or Special subframe (SS). A Special subframe may consist of a DL part, a UL part, and a Guard period. However, NR mobile communication systems can dynamically change the frame structure. Therefore, a method and device capable of dynamically changing the frame structure to support the characteristics of the NR mobile communication system described above may be required. The problem to be solved

[0005] The objective of the present invention to solve the above-mentioned problems is to provide a method and apparatus for transmitting data and control messages in a cellular network based on dynamic time division duplication in a communication system. means of solving the problem

[0006] A method of operation of a base station according to a first embodiment of the present invention for achieving an objective comprises the steps of: scheduling a slot p, whose transmission direction is not determined, for downlink transmission; determining the transmission direction of a time slot included in the slot p; if the transmission direction of the time slot is uplink, scheduling a slot p+n after the slot p for uplink transmission; and switching the state of the slot p+n-1 to a switching gap (SG) state, wherein the slot p+n-1 in the SG state is a time interval required for switching between downlink transmission and uplink transmission, and p and n are each natural numbers. Effects of the invention

[0007] According to the present invention, a dynamic time division redundancy frame structure can be efficiently configured for a communication system. That is, when a dynamic time division redundancy frame structure is configured according to the embodiments, a high transmission rate and low latency can be achieved. Accordingly, the performance of the communication system can be improved. Brief explanation of the drawing

[0008] FIG. 1 is a conceptual diagram illustrating a first embodiment of a communication system. FIG. 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system. FIG. 3a is a conceptual diagram illustrating a dynamic TDD frame structure consisting of multiple time slots in a communication system. FIG. 3b is a conceptual diagram illustrating a TDD slot cycle consisting of multiple slots in a communication system. FIG. 4 is an illustrative diagram for explaining a first embodiment of a dynamic TDD scheduling method in a communication system. FIG. 5 is a conceptual diagram illustrating a first embodiment of slot state determination and scheduling according to step 402 of FIG. 4. FIG. 6 is an illustrative diagram for explaining a second embodiment of a dynamic TDD scheduling method in a communication system. FIG. 7a is a conceptual diagram illustrating a first embodiment of a frame structure for the operation of a dynamic TDD scheduling technique in a communication system. FIG. 7b is a conceptual diagram illustrating a second embodiment of a method for allocating data transmission resources through a control message location in a communication system. FIG. 7c is a conceptual diagram illustrating a third embodiment of a method for allocating data transmission resources through a control message location in a communication system. FIG. 7d is a conceptual diagram illustrating a fourth embodiment of a method for allocating data transmission resources through a control message location in a communication system. FIG. 8a is a conceptual diagram illustrating a first embodiment of a method for expanding and shrinking frequency and time resources. FIG. 8b is a conceptual diagram illustrating a second embodiment of a frequency and time resource expansion and reduction method. FIG. 8c is a conceptual diagram illustrating a third embodiment of a frequency and time resource expansion and reduction method. FIG. 9a is a conceptual diagram illustrating a first embodiment of a method for reusing a control channel in a communication system. FIG. 9b is a conceptual diagram illustrating a second embodiment of a method for reusing a control channel in a communication system. Figure 10 shows a communication system This is a conceptual diagram illustrating a first embodiment of a method for allocating maximum uplink transmission resources when α is 3. FIG. 11 is a conceptual diagram illustrating a first embodiment of a method for transmitting a control message in an uplink time slot in a communication system. FIG. 12 is an illustrative diagram for explaining a third embodiment of a dynamic TDD scheduling method in a communication system. FIG. 13 is a conceptual diagram illustrating a first embodiment of a control channel additional configuration for fast uplink transmission in a communication system. FIG. 14 is a conceptual diagram illustrating a first embodiment of a resource allocation method for fast uplink transmission in a communication system. FIG. 15 is a conceptual diagram illustrating a first embodiment of a resource allocation method for fast uplink HARQ transmission in a communication system. FIG. 16 is a conceptual diagram illustrating a first embodiment of a method for setting a guardband interval for PUCCH transmission in a communication system. Figure 17 is a conceptual diagram illustrating multi-cell interference performing dynamic TDD in a communication system. FIG. 18 is a conceptual diagram illustrating a first embodiment of a resource nulling method for receiving downlink DM-RS in a communication system. FIG. 19 is a conceptual diagram illustrating interference between uplink and downlink transmitting and receiving terminals within a cell in a communication system. Specific details for implementing the invention

[0009] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0010] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any of a plurality of related described items.

[0011] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0012] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0013] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0014] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings. In order to facilitate an overall understanding of the present invention, the same reference numerals are used for identical components in the drawings, and redundant descriptions of identical components are omitted.

[0015] A communication system to which embodiments according to the present invention are applied will be described. The communication system to which embodiments according to the present invention are applied is not limited to the details described below, and embodiments according to the present invention may be applied to various communication systems. Here, the term "communication system" may be used interchangeably with "communication network."

[0016] FIG. 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0017] Referring to FIG. 1, the communication system (100) may include a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). The plurality of communication nodes may support 4G communication (e.g., LTE (long term evolution), LTE-A (advanced)), 5G communication (e.g., NR (new radio)), etc., as defined in the 3GPP (3rd generation partnership project) standard. 4G communication may be performed in a frequency band of 6 GHz or lower, and 5G communication may be performed not only in a frequency band of 6 GHz or lower but also in a frequency band of 6 GHz or higher.

[0018] For example, for 4G communication and 5G communication, multiple communication nodes can support communication protocols based on CDMA (code division multiple access), WCDMA (wideband CDMA), TDMA (time division multiple access), FDMA (frequency division multiple access), OFDM (orthogonal frequency division multiplexing), Filtered OFDM, CP (cyclic prefix)-OFDM, DFT-s-OFDM (discrete Fourier transform-spread-OFDM), OFDMA (orthogonal frequency division multiple access), SC (single carrier)-FDMA, NOMA (Non-orthogonal Multiple Access), GFDM (generalized frequency division multiplexing), FBMC (filter bank multi-carrier) based communication protocol, UFMC (universal filtered multi-carrier) based communication protocol, SDMA (Space Division Multiple Access) based communication protocol, etc.

[0019] Additionally, the communication system (100) may further include a core network. If the communication system (100) supports 4G communication, the core network may include an S-GW (serving-gateway), a P-GW (PDN (packet data network)-gateway), an MME (mobility management entity), etc. If the communication system (100) supports 5G communication, the core network may include a UPF (user plane function), an SMF (session management function), an AMF (access and mobility management function), etc.

[0020] Meanwhile, each of the plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) constituting the communication system (100) may have the following structure.

[0021] FIG. 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0022] Referring to FIG. 2, the communication node (200) may include at least one processor (210), a memory (220), and a transceiver (230) that is connected to a network to perform communication. Additionally, the communication node (200) may further include an input interface device (240), an output interface device (250), a storage device (260), etc. Each component included in the communication node (200) may be connected by a bus (270) to communicate with one another.

[0023] However, each component included in the communication node (200) may be connected via individual interfaces or individual buses centered around the processor (210), rather than via a common bus (270). For example, the processor (210) may be connected via a dedicated interface to at least one of a memory (220), a transmission / reception device (230), an input interface device (240), an output interface device (250), and a storage device (260).

[0024] The processor (210) can execute a program command stored in at least one of the memory (220) and the storage device (260). The processor (210) may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory (220) and the storage device (260) may be composed of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (220) may be composed of at least one of read-only memory (ROM) and random access memory (RAM).

[0025] Referring again to FIG. 1, the communication system (100) may include a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) and a plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6). The communication system (100) including the base stations (110-1, 110-2, 110-3, 120-1, 120-2) and terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as an "access network". Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can form a macro cell. Each of the fourth base station (120-1) and the fifth base station (120-2) can form a small cell. The fourth base station (120-1), the third terminal (130-3), and the fourth terminal (130-4) may be located within the cell coverage of the first base station (110-1). The second terminal (130-2), the fourth terminal (130-4), and the fifth terminal (130-5) may be located within the cell coverage of the second base station (110-2). The fifth base station (120-2), the fourth terminal (130-4), the fifth terminal (130-5), and the sixth terminal (130-6) may be located within the cell coverage of the third base station (110-3). The first terminal (130-1) may be located within the cell coverage of the fourth base station (120-1). The sixth terminal (130-6) may be located within the cell coverage of the fifth base station (120-2).

[0026] Here, each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be referred to as Node B, evolved Node B, base transceiver station (BTS), radio base station, radio transceiver, access point, access node, road side unit (RSU), radio remote head (RRH), transmission point (TP), transmission and reception station (TRP), eNB, gNB, etc.

[0027] Each of the multiple terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as a UE (user equipment), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, IoT (Internet of Thing) device, mounted module / device / terminal or on board device / terminal, etc.

[0028] Next, the resource allocation method for the downlink control channel in NR will be described. Even when a method performed by a first communication node among the communication nodes (e.g., transmission or reception of a signal) is described, the corresponding second communication node may perform a method corresponding to the method performed by the first communication node (e.g., reception or transmission of a signal). That is, when the operation of a terminal is described, the corresponding base station may perform an operation corresponding to the operation of the terminal. Conversely, when the operation of a base station is described, the corresponding terminal may perform an operation corresponding to the operation of the base station. Next, an NR mobile communication system based on the TDD method will be described.

[0029] The embodiments described below may be applied to NR as well as other communication systems (e.g., LTE). In the embodiments below, the control channel may indicate at least one of a downlink control channel (e.g., PDCCH) and an uplink control channel (e.g., PUCCH), and the control message may mean the DCI (downlink control channel).

[0030] [Dynamic TDD Frame Structure]

[0031] Figures 3a and 3b are conceptual diagrams illustrating the dynamic TDD frame structure in a communication system.

[0032] Referring to FIG. 3a, the dynamic TDD frame structure can be configured based on TDD time slots, and multiple time slots can be configured in one or multiple slots. Each time slot can be composed of a DL (downlink), UL (uplink), or SG (switching gap). Each time slot can be composed of two or more symbols and may represent a minislot. Additionally, each time slot can be composed of a minimum number of symbols for low-latency transmission.

[0033] Referring to FIG. 3b, the dynamic TDD frame structure may have a single slot state of DL, UL, or SG. A TDD slot cycle exists in units of multiple slots, and, for example, may have a cycle consisting of 5 slots as shown in FIG. 3b.

[0034] A dynamic TDD time slot may include a flexible section in which the transmission direction is not determined, and the symbols in the flexible section may be divided into time slots to have a slot configuration as shown in FIG. 3a. The flexible section may be a full slot consisting of 14 symbols, or a partial slot consisting of some of the 14 symbols.

[0035] The base station can freely determine the transmission direction and the transmitting and receiving nodes for each time slot. That is, the base station can determine the transmission direction as either downlink or uplink depending on the transmitting and receiving nodes for each time slot. Since time is required for the terminal to process the data to be transmitted (e.g., encoding) for uplink transmission, the base station may send a control message to the terminal before the time of uplink transmission. The time required for this If defined as such, the base station in the n-th time slot n+ Subsequent uplink transmission resources can be allocated.

[0036] In addition, since uplink transmission cannot be performed immediately after the downlink time slot, the base station may insert an SG time slot for switching. The SG time slot is necessary for switching between uplink and downlink transmissions and may be necessary to eliminate interference that may occur to adjacent downlink receiving terminals due to the TA (timing advance) of the uplink transmitting terminal.

[0037] [Gap-based Time Slot Scheduling Method]

[0038] FIG. 4 is an illustrative diagram for explaining a first embodiment of a dynamic TDD scheduling method in a communication system.

[0039] Referring to FIG. 4, the current state of each time slot can be defined as DL, UL, and SG, and in each transmission direction and A gap may exist. Also, the sum of the downlink or uplink queues or It can be expressed as follows. The switching condition of the DL time slot at time t can be expressed as Equation 1 below.

[0040]

[0041] According to mathematical formula 1, the base station go and If the sum is greater than or equal to, the DL time slot state can be switched to UL (S401). For example, when the base station is in the DL time slot state (i.e., when tdd_state is DL), the uplink metric is greater than the downlink metric. If the value is larger than this, the time slot status can be changed to UL.

[0042] The switching condition of the UL time slot at time t can be expressed as Equation 2 below.

[0043]

[0044] According to mathematical formula 2, the base station is go and If the sum is greater than or equal to , the UL time slot state can be switched to DL (S402).

[0045] The base station can apply a metric for each direction as the sum of the queue lengths for each direction. The base station applies a transmission rate weighted by the queue lengths in each direction (e.g., for the downlink, You can also set ) as a metric. In the previous mathematical formula is the length of the queue, can represent the transmission rate.

[0046] base station or The method for setting it involves setting a common normalized gap parameter G' and the average transmission capacity in each direction. and It could be multiplying by G'. Average transmission capacity for each transmission direction and It can be used by predicting the channel quality of each terminal at the base station or by periodically measuring it through transmission and scheduling results.

[0047] The slot state can be defined as the current state as DL, UL, and ND, and slot state ND can mean a slot state where the transmission direction is not determined. Therefore, slot state ND can be a flexible slot that can switch to another slot state.

[0048] If the slot state of slot p at time t is ND, the base station can schedule slot p as DL and set the slot state to DL (S403). Here, if the time slot state is UL at time t, the base station [can schedule] slot p+n after slot p (e.g., at time t+ ) can be scheduled as an uplink, and the slot state of slot p+n can be switched to UL. The base station slot p+n-1 (e.g., time t+ If the slot state of -1) is ND, the slot state of slot p+n-1 can be switched to SG (S404). Here, p and n can be natural numbers.

[0049] FIG. 5 is a conceptual diagram illustrating a first embodiment of slot state determination and scheduling according to step 402 of FIG. 4.

[0050] Referring to FIG. 5, the slot state before and after scheduling according to steps 403 and 404 of FIG. 4 described above can be shown.

[0051] And the base station and the terminal can perform a transmission corresponding to the slot state at time t, and if the slot state is ND, they can perform a preparatory operation to switch to uplink transmission (S405).

[0052] FIG. 6 is an illustrative diagram for explaining a second embodiment of a dynamic TDD scheduling method in a communication system.

[0053] Referring to FIG. 6, in order to apply a fast switching technique to the scheduling method of FIG. 4, the base station can obtain the minimum value of the downlink and uplink capacity regions for the gap parameter G' as follows.

[0054]

[0055] The base station uses the minimum capacity area calculated in Equation 3 for the downlink and uplink minimum hold times and It can be calculated as shown in Equation 4 below. The base station can start the minimum holding time for the downlink and uplink based on the time of switching to the downlink or uplink, respectively.

[0056]

[0057] When the base station is in the time slot state of DL, if it satisfies the condition of Equation 1 as in step 401 in the aforementioned FIG. 4, it can switch the time slot state to UL, and the duration of the UL time slot ( ) can be set to 0 (S601). Or, the base station can set the duration of the DL time slot a minimum DL time slot switching point If the scheduling metric (e.g., queue sum) becomes 0 at a point in time greater than 0, switching to the opposite uplink transmission is possible, and the duration of the UL time slot ( ) can be set to 0 (S602). If the base station does not satisfy the conditions of steps 601 and 602 described above, the duration of the DL time slot Is It can be set to +1 (S603).

[0058] When the base station is in the time slot state of UL, if it satisfies the condition of Equation 2 as in step 402 of FIG. 4 described above, it can switch the time slot state to DL, and the duration of the DL time slot ( ) can be set to 0 (S604). Or, the base station can set the duration of the UL time slot a minimum UL time slot switching point When the scheduling metric (e.g., the sum of the queues) becomes 0 at a point equal to or greater than, switching to downlink transmission is possible, and the duration of the DL time slot ( ) can be set to 0 (S605). If the base station does not satisfy the conditions of steps 604 and 605 described above, the duration of the UL time slot Is It can be set to +1 (S606).

[0059] The base station, even if the scheduling metric does not become exactly 0 in the aforementioned steps 602 and 605, has a specific minimum value Even if it is smaller, it can switch in the opposite direction. Also, depending on the definition of the metric, the minimum value of the metric may not be 0, and even in this case, the base station can switch in the opposite direction if the scheduling metric is smaller than a specific minimum value.

[0060] In the algorithm of Fig. 6 described above and is the number of consecutive DL and UL transmission schedulings, and the base station can count from the time it switches to scheduling for the opposite direction.

[0061] [Integrated Control Channel Structure for Dynamic TDD]

[0062] FIG. 7a is a conceptual diagram illustrating a first embodiment of a frame structure for the operation of a dynamic TDD scheduling technique in a communication system.

[0063] Referring to FIG. 7a, since the base station must be able to transmit DL control messages in all DL time slots for the operation of the dynamic TDD scheduling technique, it can form a frame structure as shown in FIG. 7a.

[0064] Each control message (e.g., DCI) may require transmission resources of a fixed or variable size. For example, a control message may consist of a Control Channel Element (CCE) composed of six Resource Element Groups (REG). The base station cannot use the resources used for transmitting control messages for data transmission, and this may act as overhead for data transmission.

[0065] To maintain the overhead of each time slot at a constant level for efficient network operation, the base station may limit the maximum number of control message transmission resources per time slot. For example, the base station may configure up to 4 control message resources, which may mean that up to 4 control messages (DCI) are transmitted. Each terminal may know in advance the location of the control message transmission resource (control channel) among the downlink transmission resources, and may attempt to receive control messages by decoding the received control channel at every time slot.

[0066] The base station can configure the control channel according to the configuration of the upper layer (e.g., the MAC (Medium Access Control) layer). The upper layer configuration information may include one or more of the information in Table 1 below.

[0067] IE detail N_sym_slot Time slot symbol length N_rb_subband Number of RBs constituting each subband N_cce_subband Number of CCEs per subband control_timeslot_bitmap Bitmap of the time slot where the control message is transmitted

[0068] For example, in the case of FIG. 2, N_sym_slot can be represented as 2, N_rb_subband as half of the total number of RBs (e.g., 50 in the case of a total of 100 RBs), N_cce_subband as 1, and control_timeslot_bitmap as 1111111. The terminal attempts to receive a control message at a predetermined control message location, and if it succeeds in receiving the control message, it can know that the base station is transmitting data for the receiving terminal from the corresponding subband frequency resource. Therefore, the terminal can identify the location of the frequency resource for uplink or downlink even if the control message does not include frequency resource information.

[0069] FIGS. 7b to 7d are conceptual diagrams illustrating embodiments of a method for allocating data transmission resources through control message locations in a communication system.

[0070] Referring to FIG. 7b, the base station can allocate a certain area in the downlink transmission slot as a resource for transmitting control messages, and the terminal can identify the location of the frequency resource for downlink transmission through the location of the control message.

[0071] Referring to FIG. 7c, the base station can allocate a certain area in the downlink transmission slot as a resource for transmitting control messages, and through the control message location, the terminal The location of time resources for uplink transmission after elapsed can be identified.

[0072] Referring to FIG. 7d, the base station needs to transmit control messages through one or more control channels depending on the channel quality, and can transmit downlink control messages through one or more CCEs. When the aggregation level is 2 or higher, the base station can allocate resources for downlink data transmission based on the lower subband index when utilizing multiple subband control channels.

[0073] The base station can transmit uplink and downlink control channels and data through multiple subbands or multiple time slots, without being restricted to a single time slot and subband. To this end, the base station may include time and frequency resource extension information in the control message.

[0074] FIGS. 8a to 8c are conceptual diagrams illustrating embodiments of frequency and time resource expansion and reduction methods.

[0075] Referring to FIG. 8a, frequency resource expansion information can be expressed using Freq_start and Freq_len values, and each value can be converted and applied as a base-2 value. For example, if the reference subband configured for the control channel is F_r, the Freq_start value is 0, and the Freq_len value is 1, the base station can allocate frequency resources for the F_r and F_r+1th subbands. If the Freq_start value is negative, the starting subband index is F_r- It can be +1. If the Freq_start value is 0 or positive, the starting subband index is F_r+ It can be -1. The base station depends on the Freq_len value You can allocate several subband resources.

[0076] Referring to FIG. 8b, the base station can allocate time resources for the Time_lead_sym and Time_end fields. The base station can set the reference time based on the time slot index T_r, where the control message is transmitted in the case of the downlink. In the case of the uplink, the base station can set the reference time based on T_r+ after the slot interval for uplink transmission, where the control message is transmitted. It can be set based on. The base station can determine the symbol in the Time_lead_sym field to start transmission based on the reference time slot position T_r_dl or T_r_ul. The base station can set Time_lead_sym from 0 to N_sym_slot, and if set to N_sym_slot, it means that the entire time slot immediately preceding the reference time slot is allocated as a transmission resource.

[0077] The base station allocates resources starting from a point earlier than the reference point, so that in the case of a downlink, if there is a shortage of control channel resources for resource allocation, resource allocation can be made after transmission is performed, thereby minimizing performance degradation caused by the control channel. To this end, the terminal may temporarily store the received signal from the previous time slot until the control message is received in the subsequent time slot. Additionally, for a terminal capable of switching in a symbol shorter than the time slot length, the terminal may be able to perform uplink transmission using the remaining slot, and to this end, the start time of uplink transmission may be extended.

[0078] The base station can specify the last time slot for transmission in the Time_end field, and the base station can use up to the T_r+Time_end time slot as a transmission resource. If T_r+Time_end falls outside the time slot index within the basic slot (14 symbols), the base station can perform transmission within the basic slot range.

[0079] Referring to FIG. 8c, the base station may apply the Time_end_sym field similarly to the Time_lead_sym field and allocate fewer transmission slots in symbol units based on the last transmission time slot position. The base station may use the Time_end_sym field to place fewer switching symbols than the time slot for switching in the time slot where the corresponding transmission resource is configured.

[0080] FIGS. 9a and 9b are conceptual diagrams illustrating embodiments of a control channel reuse method in a communication system.

[0081] Referring to FIG. 9a, the base station can reuse control message resources for downlink data transmission when actual control messages are not transmitted. Therefore, the downlink transmission efficiency may vary depending on the number of control messages actually transmitted. The base station may include a parameter (i.e., a control channel reuse parameter) in the DCI for downlink transmission that indicates whether each control channel is used for data transmission.

[0082] A base station may configure control channel reuse parameters as a bitmap, and each bit may indicate whether the corresponding control channel is reused. If the bit value is a first value (e.g., 1), the base station may use the corresponding control channel for data transmission. If the bit value is a second value (e.g., 0), the base station may not use the corresponding control channel for data transmission. The length of the entire bitmap may be equal to the number of control channels configured within the data channel. Instead of bitmap information, the base station may use a single bit to indicate that the resources of all control channels included in the transmission resource are being reused for data transmission.

[0083] Referring to FIG. 9b, to increase the efficiency of downlink transmission, the base station may apply a method to reduce the number of downlink control messages transmitted. When multi-time slot scheduling using a single DCI is applied, the base station can specify transmission resources for multiple time slots through a single control message, and the number of control message transmissions and overhead may be reduced. The base station may not configure control channel reuse parameters, in which case all control channels may be used as control channels.

[0084] To perform multiple time slot transmissions for the downlink, the base station may include a parameter for the number of transmission time slots to be transmitted via the DCI in the control message. The base station may include frequency resource information as well as the time slot number parameter in the DCI for downlink transmission in the n-th time slot. If the time slot number parameter is 1, the base station may perform downlink transmissions scheduled via the corresponding DCI only in the n-th time slot. Additionally, if the time slot number parameter is k, the base station may perform downlink transmissions in k time slots from time slot number n to n+k-1.

[0085] When a base station performs downlink transmission through k multiple time slots, it may use control channel resources in time slots where DCI is not transmitted as data transmission resources. Therefore, the base station can notify the terminal of the reuse of the control channel in the corresponding time slot using a k-bit bitmap. Additionally, the base station can notify the reuse of the control channel for each time slot through time slot control channel reuse parameters. The multiple time slot control channel reuse parameters may not be configured; in this case, the base station may use the control channels of all time slots as control channels.

[0086] A base station can configure control channel reuse parameters and multi-time slot control channel reuse parameters, respectively. When a base station configures both types of parameters, it can apply control channel reuse parameters to the frequency axis and multi-time slot control channel reuse parameters to the time axis. When both types of parameters are set (e.g., when the bitmap value is 1), the control channels of the time slot and frequency can be reused for data transmission.

[0087] If the base station does not require uplink transmission after multiple time slot transmissions, it may not use control channel resources after the first time slot, and in this case, it may use those resources for data transmission.

[0088] Figure 10 shows a communication system This is a conceptual diagram illustrating a first embodiment of a method for allocating maximum uplink transmission resources when α is 3.

[0089] Referring to Fig. 10, uplink transmission scheduling in a dynamic TDD network is It must be performed before the time, and therefore the maximum number of consecutive UL time slots that a base station can allocate may be limited.

[0090] To address the issue where the maximum number of consecutive UL time slots may be constrained, the base station may introduce an uplink transmission timing parameter to relax the uplink transmission timing. The uplink transmission timing parameter can be denoted by d1, and the base station [represents] the actual uplink transmission It can be performed in the +d1 time slot. For example, If this is 3 and the d1 value in the DCI for uplink transmission to be transmitted in the nth time slot is 4, the base station can perform the actual uplink transmission in the n+7th time slot.

[0091] The base station may introduce a transmission time parameter in the DCI for downlink transmission as well as in the uplink. The transmission time parameter can be denoted by d2, and the base station may perform actual downlink transmission after the time slot d2 from the time the terminal receives the DCI.

[0092] [Control Message Transmission Method]

[0093] FIG. 11 is a conceptual diagram illustrating a first embodiment of a method for transmitting a control message in an uplink time slot in a communication system.

[0094] Referring to FIG. 11, when a base station transmits control messages only in DL time slots, DL time slots are required for downlink control message transmission even when uplink resource allocation is required. Therefore, even in environments where uplink transmission is highly required, frequent DL time slot allocations, resulting in frequent switching and overhead caused by SG time slots may occur. Additionally, the maximum UL transmission rate may be limited by DL time slots that are inevitably used for control message transmission.

[0095] To resolve the aforementioned problems, in full-duplex communication, the base station, even in UL time slots and SG time slots A frame structure can be applied to perform the transmission of control messages for uplink transmission after a time slot. The time and frequency resources of the uplink signal and the downlink control message may overlap. Although interference resulting from the transmission of the downlink control message may occur during the process of receiving the uplink signal, the base station can minimize the degradation of uplink reception performance by performing signal processing such as self-interference cancellation.

[0096] A base station may require separate RF circuits for uplink and downlink transmissions that use different transmission frequency resources. Additionally, if multiple carriers can be configured, the base station can transmit control messages through the corresponding carrier during UL time slots and SG time slots through the downlink carrier that performs the transmission of control messages.

[0097] FIG. 12 is an illustrative diagram for explaining a third embodiment of a dynamic TDD scheduling method in a communication system.

[0098] Referring to FIG. 12, if the slot state of slot p at time t is UL or SG, and if the time slot state at time t is UL, then slot p+n following slot p (e.g., at time t+ ) can be scheduled as an uplink, and the slot state of slot p+n can be switched to UL. And the base station slot p+n-1 (e.g., time t+ If the slot state of -1) is ND, the slot state of slot p+n-1 can be switched to SG (S1201).

[0099] If the slot state of slot p is ND at time t, the base station can schedule downlink operations in slot p and switch the slot state to DL. If the time slot state is UL at time t, the base station [can schedule] slot p+n following slot p (e.g., at time t+ ) can be scheduled as an uplink, and the slot state of slot p+n can be switched to UL. And the base station slot p+n-1 (e.g., time t+ If the slot state of -1) is ND, the slot state of slot p+n-1 can be switched to SG (S1202).

[0100] However, depending on the configuration of the terminal, a terminal that is not capable of full-duplex communication may not be able to receive a control message at the time of performing uplink transmission, and the base station may not transmit a control message for resource allocation to the said terminal.

[0101] When a downlink control channel is configured in a TDD band where uplink transmission is performed, the base station may configure the terminal so that UL transmission is not performed on that resource. The base station may convey this information to the terminal by including a frequency band and multiple time slot control channel reuse message in the DCI, similar to the reuse of control channel resources in downlink transmission.

[0102] When control channel resource reuse operations are performed in cases where multi-time slot transmission and relaxed transmission timing operations are executed on uplinks and downlinks, a terminal transmitting or receiving data through said resource can determine whether said resource is being reused. However, other terminals within the cell can still continue to perform blind decoding on the pre-configured control channel resource.

[0103] Accordingly, to mitigate the effects such as power consumption, when a control channel resource reuse operation is performed for a certain period of time, the base station may transmit information regarding non-reception of control messages through a control message targeting all terminals within the cell or a specific group (e.g., a group of terminals requiring low-power operation). The length of the interval during which the base station commands non-reception of control messages may be configured in time slots or slot units.

[0104] [Fast Uplink Transmission Method]

[0105] FIG. 13 is a conceptual diagram illustrating a first embodiment of a control channel additional configuration for fast uplink transmission in a communication system.

[0106] Referring to FIG. 13, the base station can add a control channel for fast uplink transmission during slot-based TDD operation. The base station can add a control channel to a UL slot or a flexible slot that can be assigned to a UL within a predetermined semi-static slot period, and the control channel to be added is at the start of the corresponding slot. It can be configured at an earlier point in time. At that point in time, the transmission resource configuration may be the same as the integrated control channel configuration in each time slot described above.

[0107] When transmitting a downlink that includes the corresponding control channel location, the base station may notify the receiving terminal by including information on the subband where the control channel is configured as a bitmap, and the receiving terminal can use this information to identify the data reception resource. For fast uplink transmission, a terminal attempting to receive a control message at that location may attempt to receive the control message in the same manner as receiving an integrated control channel.

[0108] If a base station is capable of receiving control messages on the uplink using full-duplex communication, it can similarly secure a transmission area by utilizing control channel usage information per subband when allocating uplink data resources, and transmit control messages for uplink allocation from said resources.

[0109] The base station may transmit a downlink data unit (e.g., a PDCP (Packet Data Convergence Protocol) SDU or PDU) to the terminal. The terminal may receive the downlink data unit from the base station, and response data may be generated from the terminal. The base station may perform uplink resource allocation in advance to quickly receive response data from the terminal. The base station may include information on whether to allocate resources for a fast uplink response in the session (RB, Radio Bearer) configuration information. The RB configuration information may include one or more of the information in Table 2 below.

[0110] IE detail Fast_UL_tranmsmission : {0,1} Whether to set up fast UL transmission Fast_UL_data_size : {Int} Uplink data size during fast UL setup Fast_UL_processing_time : {Int.} Minimum time required to generate uplink data after receiving downlink data

[0111] In order to support an RB with a fast UL transmission function configured, the base station can pre-configure an uplink transmission format (modulation, encoding, etc.) through upper layer settings. FIG. 14 is a conceptual diagram illustrating a first embodiment of a resource allocation method for fast uplink transmission in a communication system.

[0112] Referring to FIG. 14, the base station can allocate uplink resources at the time it transmits the downlink PDCP of the RB configured with the fast uplink transmission function. The base station may additionally include Fast_UL_tx_timing, which is information indicating the time when uplink transmission resources are executed in time slot units, in the control message for downlink transmission. A terminal that receives a control message containing Fast_UL_tx_timing from the base station n+ Uplink transmission can be performed in the +Fast_UL_tx_timing slot.

[0113] FIG. 15 is a conceptual diagram illustrating a first embodiment of a resource allocation method for fast uplink HARQ transmission in a communication system.

[0114] Referring to FIG. 15, a base station may need to configure physical uplink control channel (PUCCH) resources per time slot for fast uplink HARQ (hybrid automatic repeat request) transmission in a time slot-based dynamic TDD network. The base station can configure PUCCH resources configured within each time slot through upper layer messages (e.g., Radio Resource Control (RRC) messages).

[0115] In the control message for downlink transmission, the base station can notify the terminal, in units of a basic slot, of the time at which HARQ feedback is transmitted via the uplink after the downlink transmission is performed, through the PDSCH (physical downlink Shared channel)-to-HARQ parameter. To transmit rapid feedback utilizing multiple time slots within the basic slot and the PUCCH existing in each time slot, the base station can specify the feedback timing.

[0116] When the value of the PDSCH-to-HARQ parameter is 0 in a short PDSCH transmission transmitted in a time slot, the base station may specify the time slot offset from the current base slot through the PDSCH-to-HARQ-timeslot parameter. When the base station performs a HARQ feedback transmission through a time slot within another slot, the PDSCH-to-HARQ-timeslot parameter may be set relative to the start time slot of the corresponding base slot.

[0117] When PUCCH transmission is performed over the uplink, time may be required for TA and RF (radio-frequency) transitions, just as with data transmission, and the base station may perform scheduling that takes this into account. For example, the base station may not perform downlink data transmission in the slot immediately preceding the PUCCH transmission slot.

[0118] Whether a terminal receives a PDCCH in the time slot immediately preceding the time slot where PUCCH or PUSCH (physical uplink Shared channel) transmission is performed may follow terminal-specific settings. Since the TA degree or the time for RF transition varies from terminal to terminal, the terminal's reception of a PDCCH may differ depending on the time slot length and control channel configuration. During the initial connection and location update procedure, the terminal may negotiate with the base station via an upper-layer control message whether to receive a control message prior to the uplink time slot. The base station may set a Receiving-PDCCH-before-UL-timeslot parameter having a value of 0 or 1, and the Receiving-PDCCH-before-UL-timeslot parameter may indicate whether a control message was received in the slot immediately preceding the uplink.

[0119] FIG. 16 is a conceptual diagram illustrating a first embodiment of a method for setting a guardband interval for PUCCH transmission in a communication system.

[0120] Referring to FIG. 16, when a base station schedules uplink transmission via a control message, there may be cases where the uplink transmission resources overlap with the PUCCH transmission resources of another terminal. The base station can minimize interference between PUCCH and PUSCH by not using a portion of the uplink transmission resources. The base station may include a parameter for setting a guard band in the DCI for PUSCH allocation. The base station may include the N_rb_guard parameter in the DCI and set it to have a value from -(N_rb_subband / 2)+1 to (N_rb_subband / 2)-1. If the subband index of the resource allocated through the DCI is negative, the base station may not use RBs with -N_rb_guard low indices, and conversely, if it is positive, it may not use RBs with N_rb_guard high indices.

[0121] A base station capable of full-duplex transmission and reception can perform uplink reception and downlink transmission simultaneously by dividing frequency resources. In this case, if the subbands where uplink or downlink transmission is performed are adjacent to each other, significant interference between frequencies may occur. When allocating uplink or downlink resources, the base station can configure transmission resources in a manner that does not utilize some RBs in one or more allocated subbands through the configured N_rb_guard parameter.

[0122] [Multi-cell Interference Removal in Dynamic TDD]

[0123] Figure 17 is a conceptual diagram illustrating multi-cell interference performing dynamic TDD in a communication system.

[0124] Referring to Fig. 17, if the slot schedule is the same in all cells performing TDD and there is a sufficient time interval during transmission direction switching, interference problems caused by different transmission directions between cells may not occur. However, in a network environment where each cell dynamically determines the transmission direction of the basic slot or time slot, significant interference between cells may occur. In particular, downlink transmission by a specific cell can cause significant interference to the uplink signal received by adjacent cells.

[0125] FIG. 18 is a conceptual diagram illustrating a first embodiment of a resource nulling method for receiving downlink DM-RS in a communication system.

[0126] Referring to Fig. 18, base stations can apply an uplink interference cancellation technique through information exchange between base stations to mitigate downlink-uplink interference. Each base station can know the synchronization signal block (SSB) transmission schedule through beam switching of adjacent cells and use this to measure the interference channels for each beam of adjacent cells. The base station can feed back the transmit beam index with a high degree of interference to adjacent cells, and the feedback can be performed using X2, which is an interface between base stations.

[0127] The base station may determine a transmission schedule per time slot for each cell and share it with adjacent cells. However, the base station may not exchange all schedules, and if a transmitted beam is included in the beam index fed back by an adjacent cell, it may notify the adjacent cell of such information. Upon receiving this, the base station may cancel the uplink resource allocation for the corresponding time slot and frequency resource.

[0128] The base station can perform interference cancellation to improve reception quality by removing interference signals from the uplink received signal. When allocating uplink resources, the base station can allocate resources to null the DM-RS (demodulation reference signal) resources of the downlink signal of an adjacent base station. Additionally, the base station can receive transmitted signal information from an adjacent base station through the X2 interface.

[0129] When receiving an uplink signal, the base station can measure the signal from an adjacent base station using a nulled DM-RS resource. The base station can recover the interference signal and remove it from the entire received signal by utilizing the interference signal measurement information and transmitted signal information obtained through the DM-RS resource. The base station can perform the procedure for receiving the uplink signal.

[0130] [Measuring and Avoiding Inter-Slot Interference in Dynamic TDD]

[0131] FIG. 19 is a conceptual diagram illustrating interference between uplink and downlink transmitting and receiving terminals within a cell in a communication system.

[0132] Referring to FIG. 19, the base station can measure the degree of interference between the uplink and downlink allocated in adjacent time slots between terminals and perform an efficient scheduling operation using this.

[0133] A base station may transmit uplink transmission information to adjacent terminals within a cell to measure the degree of interference. The uplink transmission information may include a TA value based on the propagation delay of the transmitting terminal, transmission power, and reference signal pattern information for channel measurement. Using the uplink transmission information, the terminal may receive the reference signal based on the time of uplink transmission by the adjacent terminal to obtain propagation delay and channel information from the uplink terminal, and then report this to the base station. Using this inter-terminal channel information, the base station can predict the extent of interference caused by the uplink terminal to the adjacent terminal receiving the downlink in the previous slot.

[0134] The base station can calculate the effective signal-to-noise ratio (SNR) using information received from the terminal as shown in Equation 5 below.

[0135]

[0136] In mathematical equation 5, N_sample represents the number of samples of the total downlink data, Target SNR represents the received SNR when there is no interference, IntfPwrOffset represents the interference signal strength relative to the base station signal strength, and N_overlap represents the number of samples where interference overlaps when there is no SG.

[0137] N_overlap can be represented by the mathematical formula 6 below.

[0138]

[0139] N_BS-UEa may represent the number of time delay samples between the base station and the downlink receiving terminal, N_BS-UEb may represent the number of time delay samples between the base station and the uplink transmitting terminal, and N_UEb-UEa may represent the number of time delay samples between the two terminals. For example, if the base station transmitting signal strength is 40 dBm, the channel attenuation between the base station and the downlink receiving terminal is 90 dB, the uplink transmitting signal strength is 23 dBm, and the channel attenuation between the uplink and downlink terminals is 80 dB, then IntfPwrOffset may be -7 dB.

[0140] The base station can determine the degree of SNR attenuation by comparing the target SNR and the effective SNR, and pairs with high attenuation may not be scheduled to adjacent downlink and uplink terminals. For example, the base station may set the attenuation threshold value (ul-dl-snr-degradation-threshold) to 5dB. In addition, the base station can use this attenuation degree to perform link adaptation of data transmitted to downlink terminals, thereby appropriately adjusting the error probability of the downlink received signal.

[0141] The base station may utilize measurement information from each terminal to more easily identify information between interfering terminals in adjacent time slots. Each terminal may utilize heterogeneous wireless devices, such as Bluetooth or wireless LAN. The base station may request all terminals within the cell to determine the presence of adjacent terminals, and terminals receiving the request may measure the presence and signal strength of adjacent terminals for a certain period. Each terminal may report a list of adjacent terminals and their signal strengths to the base station. The base station may convert the received information into distance and channel attenuation data, then convert it into target SNR and effective SNR, and utilize this for scheduling.

[0142] The methods according to the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., either alone or in combination. The program instructions recorded on the computer-readable medium may be those specifically designed and configured for the present invention, or they may be those known and available to those skilled in the art of computer software.

[0143] Examples of computer-readable media include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include machine code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The aforementioned hardware devices may be configured to operate as at least one software module to perform the operation of the present invention, and vice versa.

[0144] Although the invention has been described with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims.

Claims

Claim 1 A method of a first communication node comprising: a step of scheduling a slot p, whose transmission direction is not determined, for downlink transmission; a step of determining the transmission direction of a time slot at time of said slot p; a step of scheduling a slot p+n after said slot p for uplink transmission if the transmission direction of said time slot is uplink; a step of determining the state of slot p+n-1 as an SG (switching gap) state; and a step of switching the state of a time slot that is in a first state to a second state based on at least one of the sum of a downlink queue, the sum of an uplink queue, a downlink gap, or an uplink gap, wherein said slot p+n-1 that is in an SG state is a time interval required for switching between downlink transmission and uplink transmission, p and n are each natural numbers, and if said first state is a DL (downlink) state, said second state is an UL (uplink) state, and if said first state is an UL state, said second state is a DL state. Claim 2 A method of a first communication node according to claim 1, wherein the first state is the DL state and the second state is the UL state, and the step of switching the state of the time slot that is the first state to the second state comprises: the step of switching the state of the time slot that is the DL (downlink) state to the UL (uplink) state if the sum of the uplink queue is greater than or equal to the sum of the downlink queue plus the downlink gap; and the step of setting the duration of the time slot switched to the UL state to 0. Claim 3 A method of a first communication node according to claim 2, wherein the downlink gap is calculated by multiplying a common normalized gap parameter by the downlink average transmission capacity. Claim 4 A method of a first communication node according to claim 1, wherein the first state is the DL state and the second state is the UL state, and the step of switching the state of the time slot that is the first state to the second state comprises: switching the state of the time slot that is the DL state to the UL state when the duration of the time slot that is the DL state is greater than or equal to the minimum downlink time slot switching time and the sum of the downlink queue is 0; and setting the duration of the time slot switched to the UL state to 0. Claim 5 A method of a first communication node according to claim 1, wherein the first state is the UL state and the second state is the DL state, and the step of switching the state of the time slot that is the first state to the second state comprises: switching the state of the time slot that is the UL state to the DL state if the sum of the downlink queue is greater than or equal to the sum of the uplink queue plus the uplink gap; and setting the duration of the time slot switched to the DL state to 0. Claim 6 A method of a first communication node according to claim 5, wherein the uplink gap is calculated by multiplying the uplink average transmission capacity by a common normalized gap parameter. Claim 7 A method of a first communication node according to claim 1, wherein the first state is the UL state and the second state is the DL state, and the step of switching the state of the time slot that is the first state to the second state comprises: switching the state of the time slot that is the UL state to the DL state when the duration of the time slot that is the UL state is greater than or equal to the minimum uplink time slot switching time and the sum of the uplink queue is 0; and setting the duration of the time slot switched to the DL state to 0. Claim 8 As a first communication node, the processor includes a processor, wherein the first communication node schedules slot p, whose transmission direction is not determined, for downlink transmission; determines the transmission direction of a time slot at time of slot p; if the transmission direction of the time slot is uplink, schedules slot p+n following slot p for uplink transmission; and determines the state of slot p+n-1 as an SG (switching gap) state; A first communication node, wherein the state of a time slot, which is a first state, is switched to a second state based on at least one of the sum of a downlink queue, the sum of an uplink queue, a downlink gap, or an uplink gap, wherein the slot p+n-1, which is the SG state, is a time interval required for switching between downlink transmission and uplink transmission, and p and n are each natural numbers, and if the first state is a DL (downlink) state, the second state is an UL (uplink) state, and if the first state is an UL state, the second state is a DL state. Claim 9 In claim 8, the first state is the DL state and the second state is the UL state, and in order to switch the state of the time slot that is the first state to the second state, the processor switches the state of the time slot that is the DL state to the UL state if the sum of the uplink queue is greater than or equal to the sum of the downlink queue plus the downlink gap; and causes the duration of the time slot switched to the UL state to be set to 0, the first communication node. Claim 10 In claim 8, the first state is the UL state and the second state is the DL state, and in order to switch the state of the time slot that is the first state to the second state, the processor switches the state of the time slot that is the UL state to the DL state if the sum of the downlink queue is greater than or equal to the sum of the uplink queue plus the uplink gap; and causes the duration of the time slot switched to the DL state to be set to 0, the first communication node.

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