Search space beam

Abstract

Method for transmission binding search space of downlink control channel in OFDM transmission system. The search spaces of different monitoring occasions or different CORESETs can be bound to realize the repetition of downlink control channel. This can realize the effective transmission of downlink control channel without blocking CORESET.

Description

Technical Field

[0001] This invention relates to the binding of search spaces for PDCCH transmission, particularly for devices with reduced capabilities. Background Technology

[0002] Wireless communication systems such as third-generation (3G) mobile phone standards and technologies are well-known. These 3G standards and technologies were developed by the Third Generation Partnership Project (3GPP) (RTM). Third-generation wireless communication has been widely developed to support macrocell mobile phone communication. Communication systems and networks have evolved towards broadband and mobile systems.

[0003] In a cellular wireless communication system, User Equipment (UE) connects to the Radio Access Network (RAN) via a radio link. The RAN comprises a set of base stations and an interface to the Core Network (CN). These base stations provide radio links to UEs located in cells covered by the base stations, and the interface to the CN provides overall network control. It should be understood that the RAN and CN each perform their respective functions relevant to the overall network. For convenience, the term "cellular network" will be used to refer to the combined RAN & CN, and it should be understood that this term is used to refer to the respective systems used to perform the disclosed functions.

[0004] The 3G Partnership developed the so-called Long Term Evolution (LTE) system, also known as the Evolved Universal Mobile Telecommunication System Territorial Radio Access Network (E-UTRAN), for mobile access networks, where one or more macro cells are supported by base stations called eNodeBs or eNBs (evolved NodeBs). More recently, LTE is further evolving into the so-called 5G or NR (New Radio) system, where one or more cells are supported by base stations called gNBs. NR is proposed to use the Orthogonal Frequency Division Multiplexed (OFDM) physical transmission format.

[0005] The NR protocol is designed to provide the option to operate in unlicensed radio bands (known as NR-U). When operating in unlicensed radio bands, the gNB and UE must compete with other devices for physical media / resource access. For example, Wi-Fi (RTM), NR-U, and LAA can use the same physical resources.

[0006] The trend in wireless communication is towards providing services with lower latency and higher reliability. For example, NR aims to support Ultra-reliable and low-latency communications (URLLC), while Machine-Type Communications (mMTC) aims to provide low latency and high reliability for small packet sizes (typically 32 bytes). A user plane latency of 1ms with a reliability of 99.99999% is proposed, and a 10... -5 Or 10 -6 The packet loss rate.

[0007] mMTC services are designed to support a large number of devices over a long lifespan through energy-efficient communication channels, where data transmission between each device is sporadic and infrequent. For example, a single cell may need to support thousands of devices.

[0008] The present invention relates to various improvements to cellular wireless communication systems. Summary of the Invention

[0009] The present invention, as defined by the claims, provides a method for transmitting downlink control information in a cellular communication network using the OFDM transmission format, comprising defining a search space bundle for transmitting a downlink control channel, wherein the search space bundle includes control channel components for at least two monitoring times; transmitting the downlink control channel in the control channel component of the first of the at least two monitoring times; and transmitting at least a portion of the repetition of the downlink control channel in the control channel component of the second of the at least two monitoring times.

[0010] The transmissions during the first monitoring period use a different aggregation level than those during the second monitoring period.

[0011] The repeating repeats the system bits of the downlink control channel and includes parity bits that are different from those in the first transmission.

[0012] The control channel components for the first and second monitoring times are in the same CORESET.

[0013] The search space bundle includes at least one search space set set in the CORESET for each monitoring time.

[0014] The method also includes the step of transmitting an indication of the association between at least two search spaces.

[0015] The instruction allows the UE to decode the repetition without performing blind decoding.

[0016] The search space bundle comprises a single search space set set at each monitoring time.

[0017] The control channel components for the first and second monitoring times are in different CORESETS.

[0018] The repetition includes a subset of the bits transmitted in the first transmission, and the method further includes a second repetition that transmits at least a portion of the downlink control channel, wherein the second repetition includes a subset different from the subset transmitted in the first repetition.

[0019] The position of the control channel component during the second monitoring period is related to the position of the control channel component during the first monitoring period.

[0020] The method further includes transmitting information about the search space bundle.

[0021] The information includes an indication of how the location of the control channel component during the second monitoring period relates to the location of the control channel component during the first monitoring period.

[0022] The information includes the identifier of the CORESET containing the bound control channel component.

[0023] The CORESET is identified by a specific CORESET ID.

[0024] The specific CORESET ID is defined based on the CORESET ID of the CORESET contained in the search space bundle.

[0025] The system bits are the bits that represent DCI messages and CRC.

[0026] The CCE index of the control channel component used in the second monitoring time is defined by a function of the CCE index of the control channel component used in the first monitoring time.

[0027] The function is:

[0028] CCE Index 绑定 =f(CCE index) 初始 (CORESET size, number of repetitions, aggregation level).

[0029] A method for transmitting downlink control information in a cellular communication network using the OFDM transmission format is also provided, comprising defining a search space bundle for transmitting downlink control channels, wherein, in a single monitoring moment, the search space bundle includes control channel components of at least two CORESETs; transmitting the downlink control channels in the control channel component of a first of the at least two CORESETs; and transmitting at least a portion of the downlink control channels as a repetition in the control channel component of a second of the at least two CORESETs.

[0030] The transfers in the first CORESET use a different aggregation level than the transfers in the second CORESET.

[0031] The repeating repeats the system bits of the downlink control channel and includes parity bits that are different from those in the first transmission.

[0032] The repetition includes a subset of the bits transmitted in the first transmission, and the method further includes a second repetition that transmits at least a portion of the downlink control channel, wherein the second repetition includes a subset different from the subset transmitted in the first repetition.

[0033] The location of the control channel component of the second CORESET is related to the location of the control channel component of the first CORESET.

[0034] The method also includes transmitting information about the search space bundle.

[0035] The information includes an indication of how the location of the control channel component of the second CORESET relates to the location of the control channel component of the first CORESET.

[0036] The information includes the identifier of the CORESET containing the bound control channel component.

[0037] The CORESET is identified by a specific CORESET ID.

[0038] The specific CORESET ID is defined based on the CORESET ID of the CORESET contained in the search space bundle.

[0039] The system bits are the bits that represent DCI messages and CRC.

[0040] The CCE index of the control channel component used by the second CORESET is defined by a function of the CCE index of the control channel component used by the first CORESET.

[0041] The function is:

[0042] CCE Index 绑定 =f(CCE index) 初始 (CORESET size, number of repetitions, aggregation level).

[0043] A method for performing at a UE in a cellular communication network using the OFDM transmission format is also provided, comprising defining a search space bundle for receiving a downlink control channel, wherein the search space bundle includes control channel components for at least two monitoring times; and receiving the downlink control channel in the control channel component of a first of the at least two monitoring times, and receiving at least a portion of a repetition of the downlink control channel in the control channel component of a second of the at least two monitoring times.

[0044] The transmissions received during the first monitoring period use a different aggregation level than those received during the second monitoring period.

[0045] The repeating repeats the system bits of the downlink control channel and includes parity bits that are different from those in the first transmission.

[0046] The control channel components for the first and second monitoring times are in the same CORESET.

[0047] The search space bundle includes at least one search space set set in the CORESET for each monitoring time.

[0048] The method also includes the step of transmitting an indication of the association between at least two search spaces.

[0049] The instruction allows the UE to decode the repetition without performing blind decoding.

[0050] The search space bundle comprises a single search space set set at each monitoring time.

[0051] The control channel components for the first and second monitoring times are in different CORESETS.

[0052] The repetition includes a subset of the bits transmitted in the first transmission, and the method further includes receiving a second repetition of at least a portion of the downlink control channel, wherein the second repetition includes a subset different from the subset transmitted in the first repetition.

[0053] The position of the control channel component during the second monitoring period is related to the position of the control channel component during the first monitoring period.

[0054] The method also includes receiving information about the search space bundle.

[0055] The information includes an indication of how the location of the control channel component during the second monitoring period relates to the location of the control channel component during the first monitoring period.

[0056] The information includes the identifier of the CORESET containing the bound control channel component.

[0057] The CORESET is identified by a specific CORESET ID.

[0058] The specific CORESET ID is defined based on the CORESET ID of the CORESET contained in the search space bundle.

[0059] The system bits are the bits that represent DCI messages and CRC.

[0060] The CCE index of the control channel component used in the second monitoring time is defined by a function of the CCE index of the control channel component used in the first monitoring time.

[0061] The function is:

[0062] CCE Index 绑定 =f(CCE index) 初始 (CORESET size, number of repetitions, aggregation level).

[0063] The UE blindly decodes the first transmission and decodes the second transmission based on the received instruction.

[0064] A method for performing at a UE in a cellular communication network using the OFDM transmission format is also provided, comprising defining a search space bundle for receiving a downlink control channel, wherein, in a single monitoring time, the search space bundle includes control channel components of at least two CORESETs; receiving the downlink control channel in the control channel component of a first of the at least two CORESETs; and receiving at least a portion of the downlink control channel repetition in the control channel component of a second of the at least two CORESETs.

[0065] The receiving of transmissions in the first CORESET uses a different aggregation level than the receiving of transmissions in the second CORESET.

[0066] The repeating repeats the system bits of the downlink control channel and includes parity bits that are different from those in the first transmission.

[0067] The repetition includes a subset of the bits transmitted in the first transmission, and the method further includes a second repetition that transmits at least a portion of the downlink control channel, wherein the second repetition includes a subset different from the subset transmitted in the first repetition.

[0068] The location of the control channel component of the second CORESET is related to the location of the control channel component of the first CORESET.

[0069] The method also includes transmitting information about the search space bundle.

[0070] The information includes an indication of how the location of the control channel component of the second CORESET relates to the location of the control channel component of the first CORESET.

[0071] The information includes the identifier of the CORESET containing the bound control channel component.

[0072] The CORESET is identified by a specific CORESET ID.

[0073] The specific CORESET ID is defined based on the CORESET ID of the CORESET contained in the search space bundle.

[0074] The system bits are the bits that represent DCI messages and CRC.

[0075] The CCE index of the control channel component used by the second CORESET is defined by a function of the CCE index of the control channel component used by the first CORESET.

[0076] The function is:

[0077] CCE Index 绑定 =f(CCE index) 初始 (CORESET size, number of repetitions, aggregation level).

[0078] The UE blindly decodes the first transmission and decodes the second transmission based on the received instruction.

[0079] A base station is also provided, configured to perform the method described.

[0080] A UE is also provided, configured to perform the method described. Attached Figure Description

[0081] Further details, aspects, and embodiments of the invention will be described by way of example only with reference to the accompanying drawings. The components in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. Similar reference numerals have been included in the corresponding drawings for ease of understanding.

[0082] Figure 1 Selected components of a cellular communication network are shown;

[0083] Figure 2 An example of a CORESET being bound twice is shown;

[0084] Figure 3 An example of binding two CORESETs at once is shown;

[0085] Figure 4 An example of repeating PDCCH is shown;

[0086] Figure 5 An example of a soft merge is shown;

[0087] Figure 6 An example of forming a PDCCH signal is shown; and

[0088] Figure 7 Another example of soft combination is shown. Detailed Implementation

[0089] Those skilled in the art will recognize and understand that the details of the described examples are merely illustrative of some embodiments and that the teachings set forth herein are applicable to various alternative settings.

[0090] Figure 1 This diagram illustrates a cellular network formed by three base stations (e.g., eNB or gNB depending on the specific cellular standard and terminology). Typically, each base station will be deployed by a cellular network operator to provide geographic coverage for UEs in that area. The base stations form a Radio Area Network (RAN). Each base station provides radio coverage for UEs in its area or cell. The base stations interconnect via an X2 interface and connect to the core network via an S1 interface. It should be understood that only basic details are shown for the purpose of illustrating key characteristics of a cellular network. A PC5 interface is provided between UEs for sidelink (SL) communication. Figure 1 The related interface and component names are for illustrative purposes only. Different systems may use different naming conventions as they operate on the same principles.

[0091] Each base station contains the hardware and software for implementing RAN functions, including communication with the core network and other base stations, control and data signaling between the core network and UEs, and maintaining wireless communication with the UEs associated with each base station. The core network includes the hardware and software for implementing network functions, such as overall network management and control, and call and data routing.

[0092] It is recommended to use Reduced Capability (REDCAP) devices in NR for use cases requiring more functionality than LPWA (LTE-M / NB-IoT) but less than URLLC / eMBB services. Cost reduction is the primary driver, but extended battery life and smaller size are also attractive. One aspect of the REDCAP device proposal is reducing the number of antennas and device bandwidth, which may result in a reduced coverage area for REDCAP devices.

[0093] Due to the reduction in the number and bandwidth of UE RX antennas, downlink coverage is expected to be affected. Simulation results in R1-2003303 show that when the number of RX antennas is reduced from 4RX to 2RX, there is a performance loss of nearly 3dB at aggregation level 16, and about 6dB when reduced from 4RX to 1RX. Due to this performance degradation, the reliability of the PDCCH is of particular concern, as it may be unable to utilize the highest aggregation level due to the reduced bandwidth of REDCAP. The following discloses methods and techniques designed to compensate for the reduced coverage of the PDCCH in devices with degraded performance, but which are also applicable to devices and systems.

[0094] The following terms are used in this invention. This invention is primarily directed at the NR standard, but is also applicable to the LTE standard.

[0095] A resource block (RB) is the smallest unit of time / frequency resources that can be allocated to a user. A resource block is x-kHz wide in frequency and one time slot in time. Each resource block in the PDCCH uses 12 subcarriers, where the specific value of x depends on the subcarrier spacing (x = 12 * SCS), and can be 15kHz, 30kHz, 60kHz, etc. In terms of time, the default time slot duration in NR is 14 OFDM symbols, but it can also be a mini-slot duration (e.g., 1, 2, 4, 7, etc. OFDM symbols). The exact duration of a time slot, measured in milliseconds (ms), depends on the number of OFDM symbols on the given time slot and SCS. For example, for a 15kHz SCS and 14 OFDM symbols, one time slot is 1ms long.

[0096] • During an OFDM symbol period, a resource-element group (REG) is equal to an RB.

[0097] • A control-channel element (CCE) consists of 6 REGs.

[0098] The Physical Downlink Control Channel (PDCCH) is the physical channel that carries downlink control information (DCI). A PDCCH consists of one or more Control Center Equivalents (CCEs) (e.g., L∈{1,2,4,8}). This number is defined as the CCE aggregation level (AL). For blind decoding of the PDCCH, the set of ALs and the number of PDCCH candidates for each CCE AL of each DCI format size monitored by the UE can be configured.

[0099] For each serving cell, the UE is configured with multiple control resource sets (CORESETs) to monitor the PDCCH. Each CORESET is defined as follows: starting OFDM symbol, duration (continuous symbols, up to 3), RB set, CCE to REG mapping (and REG binding size in the case of interleaved mapping).

[0100] • CCEs can be mapped to REGs in a localized or distributed manner. Distributed resource mapping is achieved through interleaving, which is performed on the REG package. In the case of non-interleaved CCE-to-REG mapping, B = 6. In the case of interleaved CCE-to-REG mapping, B ∈ {2, 6} is used for CORESETs with 1 or 2 symbols, and B ∈ {3, 6} is used for CORESETs with 3 symbols.

[0101] The PDCCH search space at CCE AL L is defined by a set of PDCCH candidates for this CCE AL.

[0102] We define PDCCH blocking as a situation where a base station (or network) lacks sufficient resources in the cell's control area (or coreset), at least one user in the cell is not allocated these control resources and is not scheduled for service in the current transmission despite needing it. The PDCCH blocking probability is the probability of this event occurring.

[0103] To enhance the coverage of the PDCCH search space, binding techniques are disclosed below. These techniques aim to provide improved flexibility for PDCCH scheduling compared to using higher aggregation levels, while remaining within the practical limitations of decoding PDCCH, especially considering that these techniques are targeted at devices with reduced capabilities. The purpose of the following disclosure is to achieve performance similar to higher aggregation levels without consuming additional resources. In the first technique, the search space bundle can be implemented for different monitoring scenarios with the same CORESET, while in the second technique, the search space bundle is used for the same or different monitoring scenarios, but with different CORESETs.

[0104] Typically, PDCCH transmissions with high aggregation levels consume significant resources, and congestion is a major issue because the network may not have sufficient resources in the control area for other UEs monitoring the same timeframe. This is particularly problematic for REDCAP devices with reduced bandwidth. In the first example, PDCCH duplication is performed within a set of bound search spaces, located in different monitoring scenarios but within the same coreset, such as... Figure 2 As shown. The aggregation level for each search space is lower than the aggregation level. This is necessary if transmission occurs only within a single search space, but considerable reliability can be achieved due to the time overlap between monitoring events. Because of the lower aggregation level, this technique reduces the resources required for each monitoring event. However, decoding latency increases.

[0105] Bindings for the search space used for PDCCH repetition can be pre-configured for the relevant UE, for example, using higher-layer (RRC) signaling.

[0106] Using different aggregation levels for each monitoring scenario also provides increased flexibility by selecting specific combinations, and additional aggregation levels can be implemented. For example, a network can be configured with one aggregation level 4 transport and one aggregation level 8 transport in two consecutive monitoring scenarios of CORESET, which is expected to provide performance equivalent to one aggregation level 12 transport.

[0107] Soft combining can benefit from time repetition of PDCCH, but without prior repetition information, it increases the complexity of decoding operations and leads to blind decoding, as the UE must blindly decode all possible bindings. Sharing the binding configuration with the UE in advance reduces the complexity of blind decoding.

[0108] exist Figure 2In the example, a candidate in the first search space is associated with a candidate in the second search space. Search space 1 is configured with candidates at aggregation levels 1 and 2 (AL1 and 2), and search space 2 is configured with candidates at aggregation levels 2 and 4 (AL2 and 4). This configuration can be performed using the `nrofCandidates` parameter in the search space configuration. Figure 2 In the example, candidate objects in the first search space have AL2 (CCE index 0), while candidate objects in the second search space have AL4 (CCE index 4). The specific candidates and configurations are given only to illustrate the principle of defining a mapping between candidates in different search spaces, so as to repeat the PDCCH in a timely manner.

[0109] You can configure the repetition of PDCCH in the same CORESET using one of the following methods.

[0110] First, two different search space sets are configured on a CORESET for PDCCH repetition, and their association is indicated to the UE. This association allows the UE to decode the repetition without requiring blind decoding.

[0111] Configure a single search space set and repeat the PDCCH on different instances of the same search space set. The PDCCH configuration indicates to the UE which blind decoding it will perform to jointly decode the PDCCH from two instances of the search space.

[0112] The PDCCH configuration via the information component PDCCH-config includes information about the search spatial beam and is signaled to the UE. Binding information includes:

[0113] • Which search space sets are bound (multiple bindings are possible). Only a single search space set can be specified within a binding; in this case, PDCCH duplication is performed among PDCCH candidates for that single search space set.

[0114] • Information about how the PDCCH is transmitted in the binding search space (e.g., repetition scheme).

[0115] A special search space can be defined, which can be used exclusively for PDCCH repetition. As an example, search space 1, SS1, can be configured to have either repeating or non-repeating PDCCHs. It can be bound together with SS2, which is configured solely for binding purposes. Therefore, only PDCCHs already sent via SS1 can be repeated via SS2. To achieve this flexibility in PDCCH repetition without exponential complexity, SS2 can be configured with a limited number of suitable PDCCH candidates, which the configured UE will use for joint decoding of the repeated PDCCHs.

[0116] In the alternative configuration, search spaces in different CORESETs can be bound for PDCCH repetition, such as Figure 3 As shown. In a configuration similar to the previous arrangement, different aggregation levels can be used for each repetition in different CORESETs.

[0117] A new CORESET ID can be used to indicate the CORESET in use. For example, when two CORESETs are used in a BWP, a temporary CORESET ID can be defined as follows:

[0118] New CORESET ID=3*CORESET ID 1+CORESET ID 2

[0119] The new CORESET ID is transmitted to the UE by the network using RRC signaling. At the UE, two CORESET IDs can be calculated using a modulo function. A new search space ID can also be created using the same method. The search space list and the CORESET list are contained in the information component PDCCH-config. This allows the new CORESET ID or search space ID to be used as an indicator of a CORESET or search space bound to the list.

[0120] exist Figure 3 In the example, the PDCCH repeats in different cores during the same monitoring time. Therefore, in this example, the repetition is in the frequency domain. The same principle applies to using different cores in different monitoring scenarios. The search space of different cores can be bound together for PDCCH repetitions of the same DCI content. Therefore, since different cores are located in different frequency bands, additional diversity gain can be obtained due to repetitions in different cores. The PDCCH repetition configuration can be set using the two methods explained above.

[0121] The PDCCH message to be transmitted in repetitions can be defined as described in the following disclosure. System bits (i.e., bits representing message information and associated CRC bits) are transmitted using a different set of parity bits in each repetition, and some additional redundant bits are transmitted in each repetition.

[0122] The different redundant versions for each repetition are generated using the channel-coded bits of the punctured systematic bits. Each repetition has a set of coded bits that differ from the previous repetition; the systematic bits are transmitted in each repetition, but the parity bits are different for each repetition. At the receiver, each received repetition can be stored in a buffer and combined with subsequent repetitions to improve decoding. The effect of this method is that the code rate decreases with each received repetition. Each redundant version with a high code rate should be part of the low code rate master code.

[0123] Figure 4 An example of a PDCCH repeat constructed using system bits and different sets of parity bits (P1, P2, and P3) is illustrated, as discussed above. The system bits consist of the DCI message and its CRC. Each repeat can be decoded individually because they all contain the complete set of system bits and some parity bits to aid decoding. However, by combining repeats, the code rate decreases and decoding capability increases.

[0124] Figure 5 An example is shown where three repetitions of the PDCCH are transmitted at three different monitoring times in CORESET 1 (i.e., each repetition is in the same CORESET). See also: Figure 4 As explained, each repetition consists of system bits and a different set of parity bits. After the first monitoring time 1, the UE attempts to blindly decode the PDCCH. If the PDCCH in monitoring time 2 also cannot be blindly decoded, the UE performs a soft merge of the first two repetitions to reduce the code rate (due to the different parity bits in the two repetitions) and improve the prospects for decoding the PDCCH. If decoding is still unsuccessful, the third repetition can be used for blind decoding or a soft merge with the first two repetitions.

[0125] In the alternative arrangement, the system bits are transmitted only in the initial transmission of the PDCCH, and the parity bits are transmitted in all repetitions.

[0126] The system bits of the PDCCH are the DCI and CRC portions of the message, which can be encoded at a higher aggregation level (i.e., a lower code rate) than each individual repetition. The encoded bits are then punctured into different portions according to the number of repetitions, and transmitted at an aggregation level lower than that used for a single transmission. The system and first portion of the encoded bits are transmitted in the initial transmission at the lower aggregation level, while the remaining encoded bits are transmitted in other bound search spaces, which may be located in the same or different CORESETs and the same or different monitoring contexts. In effect, the larger search space with the higher aggregation level is constructed from a subset of the search space with the lower aggregation level.

[0127] For example, such as Figure 6As shown, the system bits can be encoded using an aggregation level L. When two repetitions are configured for this PDCCH, the encoded bits are divided into two parts, each with an aggregation level of L / 2. The first part is transmitted in the initial transmission, and the second part is transmitted at another time during the PDCCH transmission. In this method, only the first transmission is self-decoding because the system bits are not repeated in the second transmission. However, additional parity bits in subsequent transmissions can be used to assist decoding.

[0128] Figure 7 An example is shown where two repetitions are transmitted at two different monitoring times in two different CORESETs (CORESET1 and CORESET2). The signal transmitted in each repetition can be defined according to the principles described here. The UE performs blind detection on the first PDCCH transmission at monitoring time 1 in CORESET1. If the first transmission portion of the PDCCH is not decoded, the UE will attempt to find the second portion of the PDCCH transmission at monitoring time 2 in CORESET2. The indication of the two binding search spaces can be configured using a static predefined mode function or a semi-static configuration, as described below. The UE can then perform a soft combination with the first portion to obtain a PDCCH transmission with a higher aggregation level.

[0129] The advantage of this arrangement is that, compared to the previous proposal which included the system bit in every repetition, the system bit is transmitted only once. Therefore, PDCCH repetitions with search space aggregation can achieve additional coding rate gain due to the transmission of more parity bits in each repetition. This increases reliability and, consequently, coverage. The type of soft combination can be defined in the configuration of the PDCCH repetition, which will be discussed below.

[0130] The CCE index for the binding search space used for PDCCH repetition can be defined by a function of the CCE index of the initial PDCCH transfer, the CORESET size, the number of repetitions, and the aggregation level of the associated search space.

[0131] The parameters for the bound CORESET size, the aggregation level of the bound search space, and the number of repetitions can be set via RRC signaling. The UE performs blind decoding on the first PDCCH transmission, and the CCE index of this initial transmission is obtained through a hash function (e.g., as defined in TS38.213). Subsequent retransmission candidates will be associated with the first candidate. Therefore, a function can be defined to calculate the CCE index of the bound search space as follows:

[0132] CCE Index 绑定 = f(CCE index) 初始 (1) CORESET size, number of repetitions, aggregation level

[0133] As described above, this paper discloses two specific arrangements for binding the search space:

[0134] i. Two different search space sets are configured on the same CORESET, and their association is indicated to the UE for the purpose of PDCCH repetition.

[0135] ii. Configure a single search space set and repeat the PDCCH on different instances of the same search space set. The PDCCH configuration indicates to the UE which blind decoding it will perform to jointly decode the PDCCH from two instances of the search space.

[0136] The second approach, which performs PDCCH repetition on different CORESETs, will necessarily require two search spaces, since each search space is associated with a single, distinct CORESET.

[0137] The PDCCH configuration message sent to the UE as part of the PDCCH configuration indicates the use of PDCCH repetition, for example, by including a flag. The PDCCH configuration also indicates whether repetition will be transmitted on a single search space set or two different search space sets. The PDCCH configuration may indicate the identifier of the search space to be used.

[0138] The configuration for each search space can include binding information. Flags can indicate whether a configured search space can have PDCCH repetition. When a search space is bundled with different search spaces, the search space can have an indication of the search spaces that will be bound for PDCCH repetition. This can be achieved by including a field as part of the search space configuration that provides an identifier for the other search spaces.

[0139] Extending the configuration to additional search spaces and providing extra flexibility, the configuration of the binding search space for different instances of PDCC repetition can be indicated in two ways. These can be applied with minor adjustments to the three schemes presented above.

[0140] In the first method, the pattern of a set of binding search spaces with different aggregation levels for PDCCH repetition can be predefined by the network and provided to the UE via RRC signaling.

[0141] The bound search space can be configured with RRC signaling, including aggregation level, repetition count, resource size, and monitoring timing location. This is only one configuration for the predefined bound search space of PDCCH repetition. This configuration will then be applied periodically to PDCCH repetition. The configuration parameters for each search space cannot be dynamically changed during transmission.

[0142] The CCE index of a candidate in the bound search space can be associated with a candidate in the initial search space. It can be calculated using the function (1) defined above. An example mapping function for the bound search space is provided below. The function for calculating the CCE index of a bound candidate can be defined as:

[0143] CCE Index 绑定 ={(CCE index)} 初始 / L 初始 +CCE_offset)mod(S 绑定 / L 绑定 )}*(L 绑定 (2)

[0144] in:

[0145] S 绑定 It is based on the size of the binding search space according to the number of CCEs.

[0146] CCE_offset∈{0,1,..,min((S 初始 / L 初始 ),(S 绑定 / L 绑定 ))-1},

[0147] L 绑定 It is the aggregation level that is bound to the search space.

[0148] L 初始 It is the aggregation level of the initial search space.

[0149] The initial value of the CCE index is calculated using the hash function (2) defined in TS38.213.

[0150]

[0151] Parameters CCE_offset, L 初始 L 绑定 and S 绑定 It can be configured via RRC signaling. CCE Index 初始 The CCE index binding can be obtained through hash function (3) for the first blind decoding. Then, the CCE index binding can be computed for the following associated candidates in the binding search space using function (2). The parameter CCE_offset provides greater flexibility for resource allocation of PDCCH transmissions in the search space bundle.

[0152] In the second approach, multiple configurations for PDCCH repetition based on the search space bundle can be configured via RRC signaling. The network can limit the number of active configurations to reduce blind decoding requirements for the UE. Configuration IDs can also be associated with different sequences of PDCCH DMRS. In this case, only one configuration is enabled per PDCCH transmission, but it can be dynamically updated from one transmission to another by changing the sequence of PDCCH DMRS.

[0153] Aggregation level, search space size, CCE index for each bound search space, and soft merge type can be configured via RRC signaling. Blind decoding requirements increase when PDCCH repetition is configured. Using all combination choices can result in a maximum number of blind decodes. Therefore, the number of combinations should be limited. One solution is for the network to schedule certain predefined configurations of combinations with different aggregation levels within the search space. Thus, a certain number of blind decodes still exist due to merging, but the complexity is limited.

[0154] Another solution is to dynamically enable only one configuration during each PDCCH transmission. Different sequences of PDCCH DMRS are associated with different binding configurations. Therefore, the configuration ID can be identified by performing the association function for different sequences of PDCCH DMRS. Compared to the predefined pattern used in Proposal 2, this method provides the network with greater flexibility in terms of resource management. The network can schedule PDCCH repetitions with different combinations based on the currently available resources in the search space.

[0155] For example, the network schedules an initial PDDCH transmission and two repetitions using a combination of different aggregation levels (AL4, AL8, and AL16). Table 1 lists four possible configurations. If the search space for AL8 is available in the first monitoring scenario, the network can adopt configuration 2 or 3. If it deems it appropriate to retain AL4 and AL8, it will use configuration 2. If channel conditions are poor and the network decides to use AL8 and AL16, it can use configuration 3. Otherwise, configuration 0 or 1 can schedule the initial transmission based on the available resources per PDDCH repetition. Some combinational gain is obtained through time-domain repetition.

[0156] Therefore, it can improve coverage.

[0157] Configure index Initial transmission Repeat 1 Repeat 2 0 AL4 AL8 AL4 1 AL4 AL4 AL8 2 AL8 AL4 AL4 3 AL8 8 AL16

[0158] Table 1

[0159] In such a scheme, the DMRS will indicate the configuration index, so the UE will know which configuration is active. It can then use the known configuration bound to the search space to repeatedly perform joint decoding on the PDCCH of the active configuration.

[0160] In summary, PDCCH repetition can be performed on different CORESETs, and bound search spaces can be used at different aggregation levels to enhance coverage. The CCE index of the bound search space is associated with the CCE index of the initial search space. This approach is more flexible in PDCCH scheduling with different configuration methods. Different PDCCH repetition methods provide greater flexibility in resource management and reduce the likelihood of blocking issues.

[0161] Although not shown in detail, any device or apparatus forming part of the network may include at least a processor, memory, and a communication interface, wherein the processor, memory, and communication interface are configured to perform any aspect of the invention. Further options and choices are described below.

[0162] The signal processing functions of embodiments of the present invention can be implemented using computing systems or architectures known to those skilled in the art, particularly gNBs and UEs. Computing systems, such as desktops, laptops or notebooks, handheld computing devices (PDAs, mobile phones, PDAs, etc.), mainframes, servers, clients, or any other type of dedicated or general-purpose computing device, may be ideal or suitable for a given application or environment. The computing system may include one or more processors, which can be implemented using general-purpose or dedicated processing engines such as microprocessors, microcontrollers, or other control modules.

[0163] A computing system may also include main memory, such as random access memory (RAM) or other dynamic memory, for storing information and instructions to be executed by the processor. Such main memory can also be used to store temporary variables or other intermediate information during the execution of instructions to be executed by the processor. A computing system may also include read-only memory (ROM) or other static storage devices for storing static information and instructions for the processor.

[0164] The computing system may also include an information storage system, which may include, for example, media drives and removable storage interfaces. Media drives may include drives or other mechanisms that support fixed or removable storage media, such as hard disk drives, floppy disk drives, magnetic tape drives, optical disc drives, optical disc (CD) or digital video drive (DVD) (RTM) read or write drives (R or RW), or other removable or fixed media drives. Storage media may include, for example, hard disks, floppy disks, magnetic tapes, optical discs, CDs or DVDs, or other fixed or removable media read and written by media drives. Storage media may include computer-readable storage media in which specific computer software or data is stored.

[0165] In alternative embodiments, the information storage system may include other similar components for allowing computer programs or other instructions or data to be loaded into the computing system. Such components may include, for example, removable storage units and interfaces, such as program boxes and box interfaces, removable memory (e.g., flash memory or other removable memory modules) and memory slots, as well as other removable storage units and interfaces that allow software and data to be transferred from the removable storage units to the computing system.

[0166] The computing system may also include a communication interface. Such a communication interface can be used to allow software and data to be transferred between the computing system and external devices. Examples of communication interfaces may include modems, network interfaces (such as Ethernet or other NIC cards), communication ports (such as Universal Serial Bus (USB) ports), PCMCIA slots and cards, etc. Software and data transmitted via the communication interface are in the form of signals, which may be electronic, electromagnetic, optical, or other signals that can be received by the communication interface medium.

[0167] In this document, the terms "computer program product," "computer-readable medium," etc., are generally used to refer to tangible media, such as memory, storage devices, or storage units. These and other forms of computer-readable media may store one or more instructions for use by a processor constituting a computer system to cause the processor to perform specified operations. Such instructions, typically referred to as "computer program code" (which may be grouped as computer programs or other groups), when executed, enable the computing system to perform the functions of embodiments of the present invention. Note that code may directly cause the processor to perform specified operations, be compiled to perform such operations, and / or be combined with other software, hardware, and / or firmware components (e.g., libraries for performing standard functions) to perform such operations.

[0168] Non-transitory computer-readable media may include at least one from the group consisting of: hard disks, CD-ROMs, optical storage devices, magnetic storage devices, read-only memory, programmable read-only memory, erasable memory, EPROM, electrically erasable programmable read-only memory, and flash memory. In embodiments using software-implemented components, the software may be stored in a computer-readable medium and loaded into a computing system using, for example, a removable storage drive. When executed by a processor in a computer system, a control module (in this example, software instructions or executable computer program code) causes the processor to perform the functions of the invention as described herein.

[0169] Furthermore, the inventive concept can be applied to any circuit used to perform signal processing functions within a network element. It is further envisioned that, for example, semiconductor manufacturers can incorporate the concepts of this invention into the design of standalone devices, such as microcontrollers for digital signal processors (DSPs), or application-specific integrated circuits (ASICs), and / or any other subsystem components.

[0170] It should be understood that, for clarity, the above description has referred to embodiments of the invention with reference to a single processing logic. However, the inventive concept can also be implemented by multiple different functional units and processors to provide signal processing functions. Therefore, references to specific functional units are to be regarded only as references to suitable means for providing said functions, and not as indications of strict logical or physical structure or organization.

[0171] The aspects of this invention can be implemented in any suitable form, including hardware, software, firmware, or any combination thereof. The invention can optionally be implemented, at least in part, as computer software running on one or more data processors and / or digital signal processors or configurable modular components such as FPGA devices.

[0172] Therefore, the components and elements of embodiments of the present invention can be implemented physically, functionally, and logically in any suitable manner. In fact, functionality can be implemented in a single unit, in multiple units, or as part of other functional units. Although the invention has been described in conjunction with some embodiments, it is not intended to be limited to the specific forms set forth herein. Rather, the scope of the invention is limited only by the appended claims. Furthermore, although features may appear to be described in conjunction with specific embodiments, those skilled in the art will recognize that various features of the described embodiments can be combined according to the invention. In the claims, the term "comprising" does not exclude the presence of other components or steps.

[0173] Furthermore, although listed separately, multiple means, elements, or method steps can be implemented by, for example, a single unit or processor. Additionally, while individual features may be included in different claims, these can be advantageously combined, and inclusion in different claims does not imply that the combination of features is infeasible and / or unadvantageous. Moreover, including a feature in one class of claims does not imply a limitation on that class, but rather indicates that the feature is equally applicable to other claim classes, as the case may be.

[0174] Furthermore, the order of features in the claims does not imply any particular order in which these features must be performed; in particular, the order of the steps in a method claim does not imply that these steps must be performed in this order. Rather, these steps can be performed in any suitable order. Moreover, singular references do not exclude plural forms. Therefore, references to “a,” “an,” “first,” “second,” etc., do not exclude plural forms.

[0175] Although the invention has been described in conjunction with some embodiments, it is not intended to be limited to the specific forms set forth herein. Rather, the scope of the invention is limited only by the appended claims. Furthermore, although features may appear to be described in conjunction with specific embodiments, those skilled in the art will recognize that various features of the described embodiments can be combined according to the invention. In the claims, the terms "comprising" or "including" do not exclude the presence of other components.

Claims

1. A method for transmitting downlink control information in a cellular communication network using the OFDM transmission format, characterized in that, include: Define a search space bundle for transmitting downlink control channels, wherein the search space bundle includes control channel elements for at least two monitoring times; as well as Downlink control channels are transmitted in the control channel elements of a first monitoring time period during the at least two monitoring time periods, and at least a portion of the downlink control channels are repeated in the control channel elements of a second monitoring time period during the at least two monitoring time periods. The position of the control channel element used for repeated transmission of the downlink control channels is determined based on a functional relationship between the control channel element index used for the first transmission of the downlink control channels, the size of the control resource set (CORESET), the number of repetitions, and the aggregation level of the relevant search space. The parameters involved in the functional relationship used to determine the position of the control channel element include the size of the control resource set, the number of repetitions, and the aggregation level of the relevant search space, and these parameters are configured via Radio Resource Control (RRC) signaling. During repeated transmission, bits representing downlink control information and their corresponding Cyclic Redundancy Check (CRC) bits are encoded and transmitted using different parity bits in different repeated transmissions. Furthermore, each repeated transmission also includes additional redundant bits for enhancing decoding reliability.

2. The method according to claim 1, characterized in that, The transmissions in the first monitoring period use a different aggregation level than the transmissions in the second monitoring period.

3. The method according to claim 1, characterized in that, The repetition is used to repeat the system bits of the downlink control channel and includes parity bits that are different from those in the first transmission.

4. The method according to claim 1, characterized in that, The control channel element of the first monitoring time and the control channel element of the second monitoring time are in the same CORESET.

5. The method according to claim 4, characterized in that, The search space bundle includes at least one search space set set in the CORESET for each monitoring time.

6. The method according to claim 5, characterized in that, The method also includes the step of transmitting an indication of the association between at least two search spaces.

7. The method according to claim 6, characterized in that, The instruction allows the UE to decode the repetition without performing blind decoding.

8. The method according to claim 1, characterized in that, The search space bundle comprises a single search space set set at each monitoring time.

9. The method according to claim 1, characterized in that, The control channel element for the first monitoring time and the control channel element for the second monitoring time are in different CORESETS.

10. The method according to claim 1, characterized in that, The repetition includes a subset of the bits transmitted in the first transmission, and the method further includes a second repetition that transmits at least a portion of the downlink control channel, wherein the second repetition includes a subset different from the subset transmitted in the first repetition.

11. The method according to claim 10, characterized in that, The position of the control channel element during the second monitoring period is related to the position of the control channel element during the first monitoring period.

12. The method according to claim 1, characterized in that, It also includes transmitting information about the search space bundle.

13. The method according to claim 12, characterized in that, The information includes an indication of how the position of the control channel element during the second monitoring period relates to the position of the control channel element during the first monitoring period.

14. The method according to claim 12, characterized in that, The information includes the identifier of the CORESET containing the bound control channel element.

15. The method according to claim 14, characterized in that, The CORESET is identified by a specific CORESET ID.

16. The method according to claim 15, characterized in that, The specific CORESET ID is defined based on the CORESET ID of the CORESET contained in the search space bundle.

17. The method according to claim 3, characterized in that, The system bits are the bits that represent DCI messages and CRC.

18. The method according to claim 1, characterized in that, The CCE index of the control channel element used in the second monitoring time is defined by a function of the CCE index of the control channel element used in the first monitoring time.

19. The method according to claim 18, characterized in that, The function is: CCE Index 绑定 = f(CCE index) 初始 CORESET size, number of repetitions, aggregation level).

20. A method for transmitting downlink control information in a cellular communication network using the OFDM transmission format, characterized in that, include: Define a search space bundle for transmitting downlink control channels, wherein, in a single monitoring moment, the search space bundle includes control channel elements of at least two CORESETs; as well as Downlink control channels are transmitted in the control channel elements during a first monitoring time of the at least two CORESETs, and at least a portion of the downlink control channels are repeated in the control channel elements during a second monitoring time of the at least two CORESETs. The position of the control channel element used for repeated transmission of the downlink control channels is determined based on a functional relationship between the control channel element index used for the first transmission of the downlink control channels, the size of the control resource set CORESET, the number of repetitions, and the aggregation level of the relevant search space. The parameters involved in the functional relationship used to determine the position of the control channel element include the size of the control resource set, the number of repetitions, and the aggregation level of the relevant search space, and these parameters are configured via Radio Resource Control (RRC) signaling. During repeated transmission, bits representing downlink control information and their corresponding Cyclic Redundancy Check (CRC) bits are encoded and transmitted using different parity bits in different repeated transmissions. Furthermore, each repeated transmission also includes additional redundant bits for enhancing decoding reliability.

21. The method according to claim 20, characterized in that, The transfers in the first CORESET use a different aggregation level than the transfers in the second CORESET.

22. A method performed at a UE in a cellular communication network using the OFDM transmission format, characterized in that, include: Define a search space bundle for receiving downlink control channels, wherein the search space bundle includes control channel elements for at least two monitoring times; as well as A downlink control channel is received in the control channel element of a first monitoring time during the at least two monitoring times, and at least a portion of the downlink control channel is repeated in the control channel element of a second monitoring time during the at least two monitoring times. The position of the control channel element used for repeated transmission of the downlink control channel is determined based on a functional relationship between the control channel element index used for the first transmission of the downlink control channel, the size of the control resource set (CORESET), the number of repetitions, and the aggregation level of the relevant search space. The parameters involved in the functional relationship used to determine the position of the control channel element include the size of the control resource set, the number of repetitions, and the aggregation level of the relevant search space, and these parameters are configured via Radio Resource Control (RRC) signaling. During repeated transmission, bits representing downlink control information and their corresponding Cyclic Redundancy Check (CRC) bits are encoded and transmitted using different parity bits in different repeated transmissions. Furthermore, each repeated transmission also includes additional redundant bits for enhancing decoding reliability.

23. The method according to claim 22, characterized in that, The transmission received during the first monitoring period uses a different aggregation level than the transmission received during the second monitoring period.

24. The method according to claim 22, characterized in that, The repetition is used to repeat the system bits of the downlink control channel and includes parity bits that are different from those in the first transmission.

25. The method according to claim 22, characterized in that, The control channel element of the first monitoring time and the control channel element of the second monitoring time are in the same CORESET.

26. The method according to claim 25, characterized in that, The search space bundle includes at least one search space set set in the CORESET for each monitoring time.

27. The method according to claim 26, characterized in that, The method also includes the step of transmitting an indication of the association between at least two search spaces.

28. The method according to claim 27, characterized in that, The instruction allows the UE to decode the repetition without performing blind decoding.

29. The method according to claim 22, characterized in that, The search space bundle comprises a single search space set set at each monitoring time.

30. The method according to claim 22, characterized in that, The control channel element for the first monitoring time and the control channel element for the second monitoring time are in different CORESETS.

31. The method according to claim 22, characterized in that, The repetition includes a subset of the bits transmitted in the first transmission, and the method further includes receiving a second repetition of at least a portion of the downlink control channel, wherein the second repetition includes a subset different from the subset transmitted in the repetition.

32. The method according to claim 22, characterized in that, The position of the control channel element during the second monitoring period is related to the position of the control channel element during the first monitoring period.

33. The method according to claim 22, characterized in that, It also includes receiving information about the search space bundle.

34. The method according to claim 33, characterized in that, The information includes an indication of how the position of the control channel element during the second monitoring period relates to the position of the control channel element during the first monitoring period.

35. The method according to claim 33, characterized in that, The information includes the identifier of the CORESET containing the bound control channel element.

36. The method according to claim 35, characterized in that, The CORESET is identified by a specific CORESET ID.

37. The method according to claim 36, characterized in that, The specific CORESET ID is defined based on the CORESET ID of the CORESET contained in the search space bundle.

38. The method according to claim 24, characterized in that, The system bits are the bits that represent DCI messages and CRC.

39. The method according to claim 33, characterized in that, The CCE index of the control channel element used in the second monitoring time is defined by a function of the CCE index of the control channel element used in the first monitoring time.

40. The method according to claim 39, characterized in that, The function is: CCE Index 绑定 = f(CCE index) 初始 CORESET size, number of repetitions, aggregation level).

41. The method according to claim 22, characterized in that, The UE blindly decodes the first transmission and decodes the repeat based on the received instruction.

42. A method performed at a UE in a cellular communication network using the OFDM transmission format, characterized in that, include: Define a search space bundle for receiving downlink control channels, wherein, in a single monitoring moment, the search space bundle includes at least two control channel elements of CORESET; as well as Downlink control channels are received in the control channel elements of the first monitoring time of the at least two CORESETs, and at least a portion of the downlink control channels are repeated in the control channel elements of the second monitoring time of the at least two CORESETs. The position of the control channel element used for repeated transmission of the downlink control channels is determined based on a functional relationship between the control channel element index for the first transmission of the downlink control channels, the size of the control resource set CORESET, the number of repetitions, and the aggregation level of the relevant search space. The parameters involved in the functional relationship used to determine the position of the control channel element include the size of the control resource set, the number of repetitions, and the aggregation level of the relevant search space, and these parameters are configured via Radio Resource Control (RRC) signaling. During repeated transmission, bits representing downlink control information and their corresponding Cyclic Redundancy Check (CRC) bits are encoded and transmitted using different parity bits in different repeated transmissions. Furthermore, each repeated transmission also includes additional redundant bits for enhancing decoding reliability.

43. The method according to claim 42, characterized in that, The receiving of transmissions in the first CORESET uses a different aggregation level than the receiving of transmissions in the second CORESET.

44. The method according to claim 42, characterized in that, The UE blindly decodes the first transmission and decodes the repeat based on the received instruction.

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