Method and apparatus for sending feedback using two-level uplink scheduling

Abstract

A method includes receiving, from a base station, in a first subframe of a burst, an acknowledgment of a needed downlink transport block. A first uplink channel in which the acknowledgment of the transport block will be provided is prepared. The first uplink channel is independent of transport information. The prepared first uplink channel is transmitted together with the acknowledgment in a subsequent burst.

Description

[0001] This application is a divisional application of a Chinese patent application with application number 201680090397.5, application date August 25, 2016, and titled "Method and Apparatus for Sending Feedback Using Two-Stage Uplink Scheduling". Technical Field

[0002] The present disclosure relates to a method and apparatus, and more particularly but not exclusively, to a method and apparatus for providing a channel for confirmation. Background Art

[0003] A communication system can be regarded as a facility (such as user terminals, machine-like terminals, base stations, and / or other nodes) that enables communication between two or more devices by providing a carrier between the communication devices. For example, a communication system can be provided through a communication network and one or more compatible communication devices. Communication can include, for example, the transmission of data carrying the communication, such as voice, electronic mail (email), text messages, multimedia, and / or content data, etc. Non-limiting examples of the services provided include two-way or multi-way calls, data communication or multimedia services, and access to a data network system such as the Internet.

[0004] In a wireless system, at least a part of the communication between at least two stations occurs over a wireless interface. Examples of wireless systems include public land mobile networks (PLMNs), satellite-based communication systems, and different wireless local networks, such as wireless local area networks (WLANs). The local area wireless network technology that allows devices to connect to a data network is known by the trade name Wi-Fi (or WiFi). Wi-Fi is generally used synonymously with WLAN.

[0005] A wireless system can be divided into cells and is thus commonly referred to as a cellular system. A user can access the communication system through a suitable communication device or terminal. The user's communication device is generally referred to as a user equipment (UE). The communication device is equipped with appropriate signal receiving and transmitting means for enabling communication, such as being able to access a communication network or directly communicate with other users. The communication device can access a carrier provided by a station (such as a base station of a cell) and transmit and / or receive communication over the carrier.

[0006] Communication systems and related equipment typically operate according to a given standard or specification, which defines what the various entities associated with the system are allowed to do and how it should be implemented. Communication protocols and / or parameters for connections are usually also defined. An example of a standardized communication system architecture is the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology. LTE is being standardized by the 3rd Generation Partnership Project (3GPP). LTE uses the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access. Further development of LTE is sometimes referred to as LTE-Advanced (LTE-A). The various development stages of 3GPP specifications are called releases. In this specification, 3GPP releases are distinguished by the acronym "Rel-nn".

[0007] In addition to the LTE evolution, 3GPP has also initiated a research project for a new generation of radio (5G) called New Radio (NR). NR does not require backward compatibility with LTE. Instead, it aims to achieve tight interoperability between the RAT (Radio Access Technology) and LTE. The goal of the NR research project is to identify and develop the technical components required for the New Radio (NR) system to use any frequency band range up to at least 100 GHz. The goal can be to achieve a single technical framework that addresses the usage scenarios, requirements, and deployment scenarios defined, for example, in TR 38.913. The new radio access technology can be forward compatible to allow for standardization in two separate phases (Phase I and Phase II).

[0008] The Rel-13 LTE LAA (Licensed-Assisted Access) specification aims to provide a definition for licensed-assisted access to unlicensed radio spectrum. The access aims to coexist with other technologies and meet regulatory requirements. In Rel-13 LAA, the unlicensed spectrum is utilized to improve the LTE downlink (DL) throughput. The (5G) New Radio may also need to support unlicensed band operation. Summary of the Invention

[0009] According to one aspect, there is provided a method, including: receiving, from a base station, at least one downlink transport block that is acknowledged to be needed in at least one first subframe of a burst; preparing a first uplink channel in which the acknowledgement of the transport block will be provided, wherein the first uplink channel is independent of the transport information; causing the first uplink channel with the prepared acknowledgement to be transmitted in a subsequent burst; receiving uplink scheduling information from the base station; preparing a second uplink channel according to the uplink scheduling information received from the base station, wherein the second uplink channel depends on the transport information associated with the scheduling information; and causing the prepared second uplink channel to be transmitted in a subsequent burst.

[0010] The transmission information may include transmission time information.

[0011] The uplink scheduling information may be received in at least one downlink control channel.

[0012] The method may include receiving a trigger from the base station, wherein the transmission of the prepared first uplink channel occurs at a first time offset after receiving the trigger from the base station.

[0013] The transmission of the prepared second channel may occur at a second time offset after receiving the uplink scheduling information.

[0014] The first time offset may be less than the second time offset.

[0015] The second time offset may include x subframes after receiving the uplink scheduling information.

[0016] X may be 4.

[0017] For the second uplink channel, at least one of the following may depend on the transmission information: reference signal sequence; reference signal cyclic shift; data bit or symbol scrambling; and data bit interleaving.

[0018] The transmission information may include at least one of a subframe number and a time slot number.

[0019] At least one of the first uplink channel and the second uplink channel may include a physical uplink channel.

[0020] The first uplink channel may be a short channel.

[0021] The acknowledgement may include a hybrid automatic repeat request acknowledgement.

[0022] The first uplink channel may be a control channel.

[0023] The second uplink channel may be a shared channel.

[0024] At least one downlink transmission block may include a physical downlink channel.

[0025] The physical downlink channel may include at least one of a control channel and a shared channel.

[0026] According to another aspect, a method is provided, including: receiving, in at least one first subframe of a burst, at least one downlink transmission block for which an acknowledgement is needed from a base station; preparing a first uplink channel in which the transmission block will be provided, wherein the first uplink channel is independent of the transmission information; and causing the transmission of the prepared first uplink channel with the acknowledgement.

[0027] This aspect can be used in combination with any one or more of the above features.

[0028] According to another aspect, there is provided an apparatus, comprising: means for receiving at least one downlink transport block whose acknowledgement is required from a base station in at least one first subframe of a burst and means for receiving uplink scheduling information from the base station; means for preparing a first uplink channel and means for preparing a second uplink channel according to the uplink scheduling information received from the base station, wherein the acknowledgement of the transport block will be provided in the first uplink channel, wherein the first uplink channel is independent of the transport information, wherein the second uplink channel depends on the transport information associated with the scheduling information; and means for causing transmission of the prepared first uplink channel with the acknowledgement in a subsequent burst and means for causing transmission of the prepared second uplink channel in a subsequent burst.

[0029] The receiving means may be used to receive the uplink scheduling information in at least one downlink control channel.

[0030] The transport information may include transmission time information.

[0031] The receiving means may be used to receive a trigger from the base station, wherein transmission of the prepared first uplink channel occurs at a first time offset after receiving the trigger from the base station.

[0032] The means for causing transmission may be used to cause transmission of the prepared second channel at a second time offset after receiving the uplink scheduling information.

[0033] The first time offset may be less than the second time offset.

[0034] The second time offset may include x subframes after receiving the uplink scheduling information.

[0035] X may be 4.

[0036] For the second uplink channel, at least one of the following may depend on the transport information: reference signal sequence; reference signal cyclic shift; data bit or symbol scrambling; and data bit interleaving.

[0037] The transport information may include at least one of a subframe number and a time slot number.

[0038] At least one of the first uplink channel and the second uplink channel may include a physical uplink channel.

[0039] The first uplink channel may be a short channel.

[0040] The confirmation may include a Hybrid Automatic Repeat reQuest (HARQ) confirmation.

[0041] The first uplink channel may be a control channel.

[0042] The second uplink channel may be a shared channel.

[0043] At least one downlink transport block may include a Physical Downlink Channel (PDCCH).

[0044] The Physical Downlink Channel may include at least one of a control channel and a shared channel.

[0045] The apparatus may be provided in a User Equipment (UE).

[0046] According to another aspect, there is provided an apparatus for use in a user equipment, the apparatus including at least one processor and at least one memory, the at least one memory including computer code for one or more programs, the at least one memory and the computer code being configured to, with the at least one processor, cause the apparatus to at least: receive, in at least one first subframe of a burst, at least one downlink transport block for which a confirmation is needed from a base station; prepare a first uplink channel in which the confirmation of the transport block will be provided, wherein the first uplink channel is independent of transport information; cause the prepared first uplink channel with the confirmation to be transmitted in a subsequent burst; receive uplink scheduling information from the base station; prepare a second uplink channel according to the uplink scheduling information received from the base station, wherein the second uplink channel depends on transport information associated with the scheduling information; and cause the prepared second uplink channel to be transmitted in a subsequent burst.

[0047] The transport information may include transmission time information.

[0048] The uplink scheduling information may be received in at least one downlink control channel.

[0049] The at least one memory and the computer code may be configured to, with the at least one processor, cause the apparatus to receive a trigger from the base station, wherein the transmission of the prepared first uplink channel occurs at a first time offset after receiving the trigger from the base station.

[0050] The transmission of the prepared second channel may occur at a second time offset after receiving the uplink scheduling information.

[0051] The first time offset may be less than the second time offset.

[0052] The second time offset may include x subframes after receiving the uplink scheduling information.

[0053] X can be 4.

[0054] For the second uplink channel, at least one of the following may depend on the transmission information: a reference signal sequence; a reference signal cyclic shift; data bit or symbol scrambling; and data bit interleaving.

[0055] The transmission information may include at least one of a subframe number and a time slot number.

[0056] At least one of the first uplink channel and the second uplink channel may include a physical uplink channel.

[0057] The first uplink channel may be a short channel.

[0058] The acknowledgement may include a hybrid automatic repeat request acknowledgement.

[0059] The first uplink channel may be a control channel.

[0060] The second uplink channel may be a shared channel.

[0061] At least one downlink transmission block may include a physical downlink channel.

[0062] The physical downlink channel may include at least one of a control channel and a shared channel.

[0063] The apparatus may be provided in a user equipment.

[0064] According to another aspect, a method is provided, including: causing at least one downlink transmission block for which an acknowledgement is needed to be transmitted from a base station in at least one first subframe of a burst; receiving, in a subsequent burst, a first uplink channel with the acknowledgement, where the first uplink channel is independent of the transmission information; causing uplink scheduling information to be transmitted from the base station; and receiving, in a subsequent burst, a second uplink channel that conforms to the uplink scheduling information, where the second uplink channel depends on the transmission information associated with the scheduling information.

[0065] The transmission information may include transmission time information.

[0066] The uplink scheduling information may be transmitted in at least one downlink control channel.

[0067] The method may include causing a trigger to be transmitted from the base station, where the reception of the first uplink channel occurs at a first time offset after the transmission of the trigger.

[0068] The reception of the second channel may occur at a second time offset after receiving the uplink scheduling information.

[0069] The first time offset may be less than the second time offset.

[0070] The second time offset may include x sub - frames after transmitting the uplink scheduling information.

[0071] X may be 4.

[0072] For the second uplink channel, at least one of the following may depend on the transmission information: reference signal sequence; reference signal cyclic shift; data bit or symbol scrambling; and data bit interleaving.

[0073] The transmission information may include at least one of a sub - frame number and a time - slot number.

[0074] At least one of the first uplink channel and the second uplink channel may include a physical uplink channel.

[0075] The first uplink channel may be a short channel.

[0076] The acknowledgment may include a hybrid automatic repeat request acknowledgment.

[0077] The first uplink channel may be a control channel.

[0078] The second uplink channel may be a shared channel.

[0079] At least one downlink transmission block may include a physical downlink channel.

[0080] The physical downlink channel may include at least one of a control channel and a shared channel.

[0081] The method may be executed in a base station.

[0082] According to another aspect, there is provided an apparatus for use in a base station, the apparatus including at least one processor and at least one memory, the at least one memory including computer code for one or more programs, the at least one memory and the computer code being configured to, with the at least one processor, cause the apparatus to at least: cause the transmission of at least one downlink transmission block for which an acknowledgment is required in at least one first sub - frame of a burst; receive, in a subsequent burst, a first uplink channel with the acknowledgment, where the first uplink channel is independent of the transmission information; cause the transmission of uplink scheduling information; and receive, in a subsequent burst, a second uplink channel that conforms to the uplink scheduling information, where the second uplink channel depends on the transmission information associated with the scheduling information.

[0083] The transmission information may include transmission time information.

[0084] The uplink scheduling information may be transmitted in at least one downlink control channel.

[0085] At least one memory and computer code may be configured to, together with at least one processor, cause the device to trigger a transmission, wherein the reception of the first uplink channel occurs at a first time offset after the transmission of the trigger.

[0086] The reception of the second channel may occur at a second time offset after the reception of the uplink scheduling information.

[0087] The first time offset may be less than the second time offset.

[0088] The second time offset may include x sub - frames after the transmission of the uplink scheduling information.

[0089] X may be 4.

[0090] For the second uplink channel, at least one of the following may depend on the transmission information: reference signal sequence; reference signal cyclic shift; data bit or symbol scrambling; and data bit interleaving.

[0091] The transmission information may include at least one of a sub - frame number and a time - slot number.

[0092] At least one of the first uplink channel and the second uplink channel may include a physical uplink channel.

[0093] The first uplink channel may be a short channel.

[0094] The acknowledgement may include a hybrid automatic repeat request acknowledgement.

[0095] The first uplink channel may be a control channel.

[0096] The second uplink channel may be a shared channel.

[0097] At least one downlink transmission block may include a physical downlink channel.

[0098] The physical downlink channel may include at least one of a control channel and a shared channel.

[0099] According to another aspect, there is provided an apparatus, comprising: means for causing confirmation of at least one downlink transport block to be transmitted from a base station in at least one first subframe of a burst; and means for receiving a first uplink channel with the confirmation in a subsequent burst, wherein the first uplink channel is independent of transport information, the causing means for causing transmission of uplink scheduling information from the base station and the receiving means for receiving a second uplink channel in a subsequent burst, wherein the second uplink channel conforms to the uplink scheduling information, and wherein the second uplink channel depends on transport information associated with the scheduling information.

[0100] The transport information may include transmission time information.

[0101] The uplink scheduling information may be transmitted in at least one downlink control channel.

[0102] The means for causing transmission may be for causing a trigger to be transmitted from the base station, wherein reception of the first uplink channel occurs at a first time offset after transmission of the trigger.

[0103] The receiving means may be for receiving the second channel at a second time offset after receiving the uplink scheduling information.

[0104] The first time offset may be less than the second time offset.

[0105] The second time offset may include x subframes after transmission of the uplink scheduling information.

[0106] X may be 4.

[0107] For the second uplink channel, at least one of the following may depend on the transport information: reference signal sequence; reference signal cyclic shift; data bit or symbol scrambling; and data bit interleaving.

[0108] The transport information may include at least one of a subframe number and a time slot number.

[0109] At least one of the first uplink channel and the second uplink channel may include a physical uplink channel.

[0110] The first uplink channel may be a short channel.

[0111] The confirmation may include a hybrid automatic repeat request confirmation.

[0112] The first uplink channel may be a control channel.

[0113] The second uplink channel may be a shared channel.

[0114] At least one downlink transport block may include a physical downlink channel.

[0115] The physical downlink channel may include at least one of a control channel and a shared channel.

[0116] A computer program may also be provided, including program code components adapted to execute the methods described herein. According to a further embodiment, an apparatus and / or a computer program product are provided, which may be embodied on a non-transitory computer-readable medium for providing at least one of the above methods.

[0117] It should be understood that any feature of any aspect may be combined with any other feature of any other aspect.

[0118] Various other aspects and further embodiments are also described in the following detailed description of examples of implementing the present invention and in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0119] Some embodiments will now be described in more detail, by way of example only, with reference to the following embodiments and drawings, in which:

[0120] Figure 1 A schematic example of a system in which the present invention may be implemented is shown;

[0121] Figure 2 An example of a communication device is shown;

[0122] Figure 3A and 3B An example of interleaving is shown;

[0123] Figure 4 Group 1 and group 2 subframes and an uplink acknowledgement channel are shown;

[0124] Figure 5 A scenario in which a UE is unable to provide an acknowledgement in the current burst is shown;

[0125] Figure 6 An embodiment in which a UE is able to prepare an acknowledgement in the current burst is shown; and

[0126] Figure 7 An example of a system using an unlicensed carrier is shown;

[0127] Figure 8 A method of an embodiment is shown. DETAILED DESCRIPTION

[0128] In the following, certain exemplary embodiments are explained with reference to a wireless communication system serving devices suitable for wireless communication. Therefore, before explaining the exemplary embodiments in detail, reference is made toFigure 1 System 10, Figure 2 device 20 thereof and its control device, briefly explain some general principles of wireless systems, their components and devices for wireless communication to assist in understanding the examples described.

[0129] Communication devices can be used to access various services and / or applications provided via a communication system. In a wireless communication system, access is provided via a wireless access interface between a wireless communication device and an appropriate access system. A device can wirelessly access the communication system via a base station. A base station site can provide one or more cells of a cellular system. In Figure 1 the example of Figure 1 base station 12 can provide, for example, 3 cells on different carriers. In addition to base station 12, at least one serving cell can be provided by another or more stations. For example, at least one carrier can be provided by a station not located at base station 12. This possibility is represented by

[0130] station 11 in

[0131] The interaction between different stations and / or their controllers can be arranged in various ways. Each communication device 20 and base station can have one or more radio channels open simultaneously and can receive signals from more than one source.

[0132] A base station can have a control device 13 and / or can be connected to a controller having a control device. In the latter case, the controller can serve multiple base stations.

[0131] A base station node can be connected to a data network 18 via an appropriate gateway 15. The gateway function between an access system and another network (such as a packet data network) can be provided by any appropriate gateway node, such as a packet data gateway and / or an access gateway. Thus, a communication system can be provided by one or more interconnected networks and their elements, and one or more gateway nodes can be provided for interconnecting various networks.

[0132] Communication devices can access a communication system based on various access technologies, such as access technologies based on the specifications of the 3rd Generation Partnership Project (3GPP). A non-limiting example of a mobile architecture is referred to as an Evolved Universal Terrestrial Radio Access Network (E-UTRAN). A non-limiting example of a base station of a cellular system is what is referred to as a NodeB or an Evolved NodeB (eNB) in the vocabulary of the 3GPP specifications. An eNB can provide E-UTRAN features to a mobile communication device, such as user plane radio link control / media access control / physical layer protocol (RLC / MAC / PHY) and control plane radio resource control (RRC) protocol terminations.

[0133] Figure 2A schematic partial cross-sectional view of a communication device 20 that a user can use for communication is shown. Such a communication device is commonly referred to as a user equipment (UE) or a terminal. A suitable communication device can be provided by any device capable of transmitting and receiving radio signals. Non-limiting examples include a mobile station (MS) such as a mobile phone or a so-called "smartphone", a portable computer equipped with a wireless interface card or other wireless interface facilities, a personal data assistant (PDA) equipped with wireless communication capabilities, or any combination thereof. The mobile communication device can provide, for example, communication for carrying data for communication, such as voice, electronic mail (email), text messages, multimedia, location data, other data, etc. Thus, many services can be supplied and provided to the user via their communication device. Non-limiting examples of these services include two-way or multi-way calls, data communication or multimedia services, or simply access to a data communication network system such as the Internet.

[0134] The communication device is typically equipped with at least one data processing entity 23, at least one memory 24, and optionally other possible components for the software- and hardware-assisted execution of the tasks it is designed to perform, including controlling access to and communication with a base station and / or other user terminals. The data processing, storage, and other related control means can be provided on a suitable circuit board and / or in a chipset and / or in one or more integrated circuits. This device is denoted by reference numeral 26.

[0135] The various functions and operations of the communication device are arranged in layers according to a hierarchical model. In this model, the lower layers report to and receive instructions from the higher layers.

[0136] The user can control the operation of the device 20 through a suitable user interface such as a keypad, voice commands, a touch-sensitive screen or touchpad, a combination thereof, etc. A display 25, a speaker, and a microphone are typically also provided. In addition, the mobile communication device can include suitable connectors (wired or wireless) to other devices and / or for connecting external accessories (such as a hands-free device) to it.

[0137] The device 20 can receive and transmit signals 28 via suitable means for receiving and transmitting signals. In Figure 2 this case, the transceiver means is schematically designated by block 27. The transceiver means can be equipped with cognitive radio capabilities. The transceiver can be provided, for example, by a radio section and an associated antenna arrangement. The antenna arrangement can be disposed inside or outside the mobile device. The wireless communication device can be configured with a multiple-input / multiple-output (MIMO) antenna system.

[0138] 3GPP has defined the concepts of user equipment (UE) specific primary cell (PCell) and secondary cell (SCell). In applications such as carrier aggregation, at least but usually only one serving cell is designated as the primary cell (PCell), while the other serving cells are secondary cells (SCells). In the context of LAA, one or more LAA DL secondary cells (SCells) can be configured for a user equipment (UE) as part of a DL carrier aggregation (CA) configuration, while the primary cell (PCell) needs to be on licensed spectrum. It is expected that Rel-13 LTE LAA will also evolve to support LAA uplink (UL) transmission on unlicensed spectrum in subsequent releases (e.g., in LTE Rel-14).

[0139] The LTE LAA approach in Rel-13 based on the CA framework assumes the transmission of uplink control information (UCI) on the PCell (licensed band). However, LAA can be extended to utilize uplink support, including UCI transmission on PUCCH (physical uplink control channel) and PUSCH, as well as in dual connectivity operation (i.e., allowing non-ideal backhaul between the PCell in licensed spectrum and the SCell in unlicensed spectrum).

[0140] Independent LTE operation on unlicensed spectrum may be required in some applications. Independent LTE operation on unlicensed spectrum would mean that the eNB / UE air interface relies solely on unlicensed spectrum without any carrier on licensed spectrum.

[0141] Both dual connectivity and independent operation modes require the transmission of UCI / PUCCH on unlicensed spectrum.

[0142] Listen-before-talk (LBT) type protocols can be used for opportunistic resource allocation. Listen-before-talk is a contention-based protocol that is used in wireless communication by allowing several devices to share the same spectrum or channel. If a device wants to transmit information, the device must first check whether the channel is not already in use.

[0143] In LTE operation on unlicensed carriers, depending on regulatory rules, the UE may need to perform LBT before any UL transmission. However, there may be some exceptions.

[0144] At least in some regions, ACK / NACK (acknowledgment / negative acknowledgment) feedback can be transmitted without LBT when immediately following a DL transmission (similar to Wi-Fi operation).

[0145] The Short Control Signaling (SCS) rules defined by ETSI (European Telecommunications Standards Institute) for Europe allow control signaling to be transmitted within a 50 ms period with a duty cycle of no more than 5% without performing LBT. Short control signaling transmission is used by adaptive devices to send management and control frames (e.g., ACK / NACK signals) without sensing whether there are other signals on the channel. Adaptive devices may not be required to implement short control signaling transmission.

[0146] If implemented, the short control signaling transmission of an adaptive device can have a maximum duty cycle of 5% within a 50 ms observation period. At least in some regions, when the transmission directly follows a DL transmission for which the eNodeB has previously performed LBT and the total transmission time covering both DL and UL is limited by the maximum TX burst time defined by the associated regulator, scheduled UL transmission can generally be allowed without LBT.

[0147] Another example is that at least in some regions, when the transmission directly follows a DL transmission for which the eNodeB has previously performed LBT and the total transmission time covering both DL and UL is limited by the maximum transmission TX burst time defined by the appropriate regulator, scheduled UL transmission can generally be allowed without LBT (or with only 1 LBT).

[0148] The short PUCCH is a PUCCH structure that occupies several symbols (such as 4 symbols). The short PUCCH is time-domain multiplexed with the PUSCH (Physical Uplink Shared Channel). The short PUCCH can support two or more short PUCCH formats. For example, there can be a short PUCCH format designed to transmit multiple HARQ (Hybrid Automatic Repeat reQuest)-ACK bits, and another short PUCCH format designed to transmit the PRACH (Physical Random Access Channel), SR (Scheduling Request), and SRS (Sounding Reference Signal).

[0149] The long PUCCH refers to a PUCCH structure that occupies the PUSCH B-IFDMA (Interleaved Frequency Division Multiple Access) interleaving and a predefined transmission timing (such as 1 ms, i.e., 14 SCFDMA (Single Carrier Frequency Division Multiplexing) symbols). The long PUCCH is frequency-domain multiplexed with the PUSCH.

[0150] Since sPUCCH is located after the DL TX burst, it may not need to have the full Category 4 LBT with exponential backoff. Category 4 is an LBT mechanism agreed upon in 3GPP. It is based on CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance), which is a protocol used in Wi-Fi. This protocol has deferral periods such as DIFS (DCF (Distributed Coordination Function) Inter-Frame Space) or AIFS (Arbitration Inter-Frame Space). It uses an adaptive contention window size (q value) (exponential backoff).

[0151] Instead of Category 4 LBT, it can be based on single LBT or no LBT. - In this mode, the transmitting node shall sense the channel for at least one sensing interval (such as 25 μs) immediately before transmission on the channel. If the power detected during the sensing interval is less than the energy detection threshold, the node can transmit on the channel immediately after sensing the channel.

[0152] LTE stand-alone operation can be developed in a proprietary manner. An example of this is MulteFire (MLF) developed by Nokia. In MulteFire, support for two types of PUCCH formats - short PUCCH and long PUCCH - has been proposed.

[0153] The goal of MulteFire technology is to create a new telecommunications system where LTE radio technology is used in unlicensed radio bands. Some embodiments can support conventional LTE by extending LTE services to unlicensed radio bands using, for example, a so-called MulteFire radio. However, it should be understood that the embodiments are not limited to LTE-type cellular services and can support, for example, 3G radio services or 5G radio services. Alternatively or additionally, MulteFire can provide local Internet connectivity and / or mobility within a MulteFire network. In some embodiments, this can exist independently of any cellular operator and / or subscriber identity module (SIM) card.

[0154] A MulteFire radio can exist independently of an LTE radio in a licensed band. This is in contrast to 3GPP-specific unlicensed technologies such as LAA and LTE-U, which are designed to operate on unlicensed band frequencies. Only by way of example, MulteFire can operate in the same 5 GHz band in which Wi-Fi operates. Alternatively or additionally, any other suitable band can be used. MulteFire technology can also be applied to certain spectrum sharing scenarios, such as the 3.5 GHz band in the United States.

[0155] Reference Figure 7 , Figure 7The proposed MulteFire system is schematically shown. On the radio interface, MulteFire can rely on LTE technology. In some embodiments, there may be as few modifications as possible compared to LTE. In the MulteFire system, user equipment such as the previously described user equipment 2 can be used. These user equipments are Figure 7 labeled as UE2 in it. These devices can be traditional user equipments configured and / or capable of being used with Wi-Fi. Alternatively or additionally, traditional user equipments can be modified to operate with the MulteFire network. Alternatively or additionally, user equipments configured to work specifically with the MulteFire network can be provided.

[0156] The MulteFire system will use access points AP 4. These access points can be base stations, etc. In the MulteFire system, the radio interface can terminate on the UE 2 and on the AP 4 on the network side.

[0157] The access point AP 4 can be connected to the backhaul 6. The backhaul 6 can be configured to be connected to an IP network 8, etc. The IP network 8 can be coupled to a cellular core network 9 or a dedicated core network 7. Thus, the MulteFire access point AP 6 can be connected to a traditional cellular core network 9, namely the EPC (Evolved Packet Core). This is the LTE packet core. The MulteFire deployment in this model can be called the EPC connection mode. In another embodiment, the access point AP 6 can alternatively or additionally be connected to a MulteFire core network (MF CN) 7 that provides the necessary core network functions for MulteFire operation. This deployment model can be called the neutral host mode. In some embodiments, the MulteFire CN can be as simple as possible. For example, in some embodiments, the MulteFire core network can be provided in one physical network device hardware. In some embodiments, the MulteFire core network can be integrated into one or more APs. Alternatively, the MulteFire CN can also be implemented as a virtualized implementation. When the MulteFire network is deployed with the MulteFire core network, the network setup can use aspects of typical Wi-Fi deployments.

[0158] Due to regulatory restrictions, UL transmissions in proprietary systems such as MulteFire are based on an interleaving consisting of multiple (e.g., 6 or 10) equally spaced 1-PRB (Physical Resource Block) clusters.

[0159] In particular, uplink resource allocation in MulteFire can be based on B-IFDMA (Block Interleaved Frequency Division Multiple Access). This design can be based on an interleaving of 10 10-PRB (Physical Resource Blocks) with a bandwidth of, for example, 20 MHz.

[0160] Reference Figure 3A and 3B , Figure 3A and 3B shows one interleaving. The interleaving has 10 evenly spaced resource blocks labeled 101 to 110. These interleaved resource blocks are in groups of 10. The minimum allocation for a 20 MHz bandwidth corresponds to 10 PRBs.

[0161] B-IFDMA is also adopted for Rel-14 LAA UL.

[0162] sPUCCH transmission utilizes one or more interleavings in frequency and a predetermined number of DFT-S-OFDMA (Discrete Fourier Transform Spread Orthogonal Frequency Division Multiple Access) symbols in time, such as 4 symbols.

[0163] Now, C-PDCCH (Common Physical Control Channel) will be described. Rel-13 LAA supports common signaling to indicate the type (normal or DwPTSO (Downlink Pilot Time Slot)-like) of the current and next subframes. DCI (Downlink Control Information) format 1C is used for common signaling, and the indication defined for Rel-13 produces a 4-bit payload. Thus, when operating at 9 bits for a 20 MHz carrier bandwidth and 10 MHz cases respectively, there are 11 bits available for future use (such as for indication of UL subframes).

[0164] The UL burst indicator included in the C-PDCCH can facilitate further power savings for unscheduled UEs. When a Rel-14 UE receives a UL TX burst indicator for certain subframes, it can consider such subframes as DRX (Discontinuous Reception) subframes (if the subframe is not a UL subframe with a valid PUSCH (Physical Uplink Shared Channel) grant). If the subframe is considered a discontinuous reception subframe, BB (Baseband) samples including FFT (Fast Fourier Transform) operations are not created, detection of DL transmissions, such as blind detection based on CRS (Common Reference Signal), is not attempted, and the (E)PDCCH ((Enhanced) Physical Downlink Control Channel) is not monitored during the indicated UL subframe.

[0165] The current C-PDCCH design related to UL bursts is currently open in both LAA and MulteFire. The available bits of the C-PDCCH (i.e., 11 bits in the case of a 20 MHz carrier) can be used to indicate the attributes of the UL TX burst. The proposed information element can include one or more of the following: the starting subframe of the UL burst regarding the position of the indicator (subframe offset); the UL TX burst length (maximum channel occupancy time) within the MCOT; indicating the no-LBT option for SRS / UCI (signaling reference signal / uplink control information); ePUCCH (enhanced PUCCH) trigger; capable of transmitting outstanding two-stage authorizations; and sPUCCH-related information.

[0166] The C-PDCCH indicates the time position of the sPUCCH. Therefore, the UE detects the C-PDCCH to transmit UCI such as HARQ-ACK (Hybrid Automatic Repeat Request - ACK) via the sPUCCH.

[0167] LTE LAA and MulteFire currently both propose using n+4 timing as the minimum constraint for the UE to send ACK / NACK information for the PDSCH (Physical Downlink Shared Channel) received in subframe n. In other words, the HARQ-ACK feedback for the DL transport block received in subframe n is transmitted as early as in subframe n+4. In this regard, refer to Figure 4 . The PDSCH 120 is scattered in the PDCCH122. The sPUCCH is labeled 124. The first 3 subframes are in group 1, and the last 3 subframes are in group 2, which are in the same burst.

[0168] In some embodiments, in group #1: the HARQ-ACK for processing DL HARQ during the current DL Tx burst, and in group #2: the HARQ-ACK for not processing DL HARQ during the current DL Tx burst, i.e., outstanding HARQ-ACK.

[0169] The n+4 constraint results in the following DL subframe groups: group #1: the HARQ-ACK for processing the DL HARQ process during the current DL TX burst in the first sPUCCH 124; and group #2: the HARQ-ACK for not processing the DL HARQ process during the current DL TX burst. Since the HARQ-ACKs are not ready for transmission after the current DL TX burst ends, they are called outstanding HARQ-ACKs and can be sent in the sPUCCH 124 of the next burst. Alternatively or additionally, these can be transmitted by some other container such as the ePUCCH, or the HARQ-ACK can be multiplexed with UL data on, for example, the PUSCH.

[0170] The timing rules for HARQ-ACK via sPUCCH can be represented by the following logic: Group #1: Use the sPUCCH transmitted immediately after the end of the current DL TX burst; and Group #2: If the C-PDCCH corresponding to the next DL TX OP (transmission opportunity) is detected, then transmit the Group #2 HARQ ACK via the sPUCCH transmitted immediately after the end of the next DL TX burst. Alternatively or additionally, these can be transmitted by some other container such as ePUCCH, or the HARQ-ACK can be multiplexed with UL data on, for example, the PUSCH.

[0171] The n+4 constraint can also relate to PUSCH scheduling. The sPUCCH trigger can involve shorter processing time requirements, such as n+2.

[0172] Some embodiments can facilitate such short processing times on the UE side.

[0173] Some embodiments can provide system enablers to facilitate a reduction in UE processing time on the UE side. As will be discussed in more detail, this can include UL designs where the UE can start generating UL signals to be transmitted (such as HARQ-ACK on the sPUCCH) without knowing the actual time (such as the subframe index) at which the transmission will occur.

[0174] Some embodiments can address issues related to UE processing time for C-PDCCH detection or more generally UCI triggering. The UE may need to determine the subframe position of the UCI / sPUCCH from the C-PDCCH or other UCI triggers. However, in some cases, Group #1 may not always be present. In these cases, the UE may not have enough time to determine the UCI / sPUCCH position for transmitting outstanding HARQ-ACKs (especially when considering the n+4 constraint for UCI / sPUCCH triggering). In this regard, reference Figure 5 , Figure 5 illustrates the problem. When the DL burst (the second DL burst 142 in this example) has fewer than 4 DL subframes (2 here), there is no time to trigger the UCI / sPUCCH 124 during this DL burst. As a result, the transmission opportunity for the outstanding HARQ-ACK from Group #2 from the first DL burst 132 is missed.

[0175] As a result, the eNB may not be able to utilize DL TX bursts with short lengths. In the Figure 5 example shown, the second burst 142 has only 2 DL subframes. Thus, the UCI / sPUCCH124 cannot be triggered in the burst and remains n+4 timed. This can be regarded as a limitation related to unlicensed band operation. For example, in Japan, the maximum burst length is only 4 ms.

[0176] One option could be to apply a timing constraint other than (n + 4) for sPUCCH triggering (e.g., n + 2).

[0177] Some embodiments may pre - provide for preparing the UCI packet before receiving the actual trigger for UCI transmission. Thus, in some embodiments, the UE can start generating the UL signal to be transmitted (e.g., HARQ - ACK on sPUCCH) without knowing the actual time (such as sub - frame index) at which the transmission will occur. Currently in LTE, the UE cannot do this because due to the randomization scheme used, the signal to be transmitted depends on the sub - frame / slot index.

[0178] Some embodiments relate to sPUCCH triggered via a common downlink control information (DCI) message. For example, this could be in systems such as MulteFire.

[0179] Some embodiments may facilitate favorable conditions for the UE such that the UE can pre - prepare HARQ - ACK transmissions (and / or other UCI such as SR and / or CSI) without detecting the actual trigger for transmission.

[0180] In some embodiments, two operating modes are provided for the UE. These operating modes will now be described.

[0181] In the first operating mode, the trigger is based on a predefined timing constraint, e.g., the n + 4 constraint. UCI generation is such that the UCI content (e.g., randomization applied on a sequence) depends on the sub - frame number in which the UCI is transmitted. This can be optimized for cases where the duration of the DL burst is typically at least 4 sub - frames and / or interference randomization is prioritized over delay reduction. Effective randomization is attractive in cases where frequency reuse 1 is applied or in the case of co - channel co - existence with another network using the same radio access technology. Frequency reuse 1 corresponds to the frequency reuse typically used in cellular systems (i.e., reusing the same resource units in adjacent cells). Such LBT results in TDM (time - division multiplexing between cells). Supporting reuse 1 operation on top of LBT may require specific arrangements.

[0182] The UCI may include one or more of the following: HARQ acknowledgement, channel state information (e.g., CQI (channel quality information), RI (rank indicator), PMI (pre - coding matrix indicator)); scheduling request indicator (SRI); and physical random access channel (PRACH)

[0183] Some embodiments may have a second mode. This mode can be optimized, for example, for Wi-Fi co-channel coexistence scenarios or other scenarios where the number of DL subframes in a burst is typically less than 4 and / or latency may be critical. UCI generation is performed independently of the subframe number in which the UCI transmission occurs (e.g., based on a cell-specific sequence that does not change over time). The UE can trigger UCI with a relatively short processing time (e.g., n+2n+1 or n+0). This second mode can be applied to one or more of the following: SR; SRS; HARQ / ACK; and CSI.

[0184] The eNB can select the configuration option via higher layer signaling or dynamically. In this second mode, n+k, e.g., n+4, can be retained as the minimum constraint for the UE to process the DL transport block and prepare for the transmission of UCI information. The relaxed processing time can only involve UCI triggering, i.e., the time between UCI triggering and the corresponding UCI transmission.

[0185] In some embodiments, the second operating mode can be the default operating mode for channels operating with a certain (e.g., tightest) time constraint. For example, the second mode can be applied for sPUCCH triggering based on the n+2 constraint, while the first mode can be applied for ePUCCH triggering based on the n+4 constraint.

[0186] Figure 6 An embodiment applied to HARQ-ACK transmission in an unlicensed band scenario is schematically shown. In this case, the common PDCCH (C-PDCCH) is used as the UCI trigger. The UE can start preparing for UCI 124 transmission for the next TXOP during the current TXOP based on a pre-trigger, e.g., during the group 2 downlink subframes labeled 150. This can be during any of the group 2 downlink subframes. In Figure 6 In the example shown, the pre-trigger is in the third group 2 downlink subframe. The pre-trigger can be explicitly indicated via downlink control information, or alternatively, the UE can default to preparing for UCI transmission after receiving one or more group 2 (DL) subframes and detecting the C-PDCCH / sPUCCH timing in the current TXOP (or DL TX burst). The UE uses blind detection to monitor the C-PDCCH from the PDCCH.

[0187] In one embodiment, when the UE is configured to operate in the second mode, it may use the C-PDCCH / sPUCCH timing corresponding to the current TXOP (or DLTX burst) as an implicit indicator to start preparing the UCI / sPUCCH transmission for the next TXOP. The C-PDCCH / sPUCCH timing is also used to determine group 1 and group 2. In some embodiments, when the UE has received the last subframe of group 2, it may start preparing the sPUCCH to be transmitted in the next Tx OP. At this time, the UE already knows the HARQ-ACK content of the entire group 2 subframes.

[0188] In another embodiment, additional dynamic signaling is introduced to switch between the first operating mode and the second operating mode. In the first operating mode, the UE does not start preparing the UCI transmission until it detects a C-PDCCH with UCI / sPUCCH trigger in the next TXOP. In the second operating mode, the UE starts preparing the UCI / sPUCCH transmission (for the next TXOP) after detecting a C-PDCCH with UCI / sPUCCH trigger in the current TXOP or at least before receiving a C-PDCCH with UCI / sPUCCH trigger corresponding to the next TXOP.

[0189] This signaling can be provided in any suitable manner. For example, the signaling can be in the DL grant that triggers the PDSCH or C-PDCCH.

[0190] Now refer to Figure 8 , Figure 8 which shows a method of an embodiment.

[0191] In step S1, the UE is configured. The UE can be configured for mode 1 or mode 2. In this method, the UE is configured for mode 2. The UE can receive information from the eNB that causes the UE to configure itself for mode 2. This information can be received, for example, via higher layer signaling (dedicated or general). The UE can also be configured for cell-specific sequences (such as DMRS (demodulation reference signal) sequences) and / or a randomization pattern that does not change between subframes.

[0192] In step S2, the UE receives the PDCCH and PDSCH corresponding to the group #1 and group #2 subframes of the current TXOP from the eNB, i.e., the DL TX burst.

[0193] In step S3, the UE determines the HARQ ACK for each HARQ process involved.

[0194] In step S4, the UE triggers the UCI transmission / sPUCCH for the group 1 subframes and then transmits the UCI transmission / sPUCCH in the first burst.

[0195] In step S5, the UE prepares UCI transmission / sPUCCH for group 2. This can typically be in parallel with step S4.

[0196] In step S6, in burst 2, detect the UCI transmission / sPUCCH trigger in, for example, the C-PDCCH corresponding to the next TXOP.

[0197] In step S7, determine whether group 1 exists in the next TXOP, i.e., the next data burst.

[0198] If group 1 exists, the next step is step S8, where UCI transmission / sPUCCH is prepared according to the n + 4 constraint (or other suitable timing constraint).

[0199] If group 1 does not exist, the next step is step S9, and the UCI transmission / sPUCCH prepared in step S5 is considered the UCI transmission / sPUCCH to be transmitted.

[0200] In step S10, transmit the prepared UCI / sPUCCH. The resources used can be derived from the last detected PDCCH used to allocate PDSCH according to the n + 4 constraint. (That is, from the last detected PDCCH, but still 4 subframes before the UCI transmission / sPUCCH).

[0201] Thus, in some embodiments, when operating according to mode 2, UCI generation is performed independently of the subframe (and / or slot) index in which the UCI transmission occurs. This can include one or more of the following features:

[0202] The DMRS sequence does not depend on the subframe index;

[0203] The cyclic shift hopping (if applied) does not depend on the subframe index;

[0204] The bit / symbol scrambling (if applied) does not depend on the subframe index; and

[0205] The bit interleaving (if applied) does not depend on the subframe index.

[0206] In some embodiments, instead of subframe index dependence, the randomization can be based on cell-specific sequences / patterns.

[0207] Some embodiments can support short DL TX bursts without increasing the UE detection burden.

[0208] Some embodiments can operate in unlicensed frequency bands to minimize latency. It should be understood that the UE prepares sPUCCHs that are not transmitted if the next TXOP contains group #1 and group #2 subframes, but are only transmitted if the next TXOP or data burst only includes group #2 subframes.

[0209] Note that the problems discussed above are not limited to any particular communication environment, but can occur in any suitable communication system.

[0210] Some embodiments can be used, for example, in 4G and / or 5G, such as NR technology or similar technologies.

[0211] The required data processing apparatus and functions can be provided by one or more data processors. The described functions can be provided by a separate processor or an integrated processor. The data processor can be of any type suitable for the local technical environment, and as a non-limiting example, can include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), gate-level circuitry, and a processor based on a multi-core processor architecture. The data processing can be distributed over several data processing modules. The data processor can be provided by, for example, at least one chip. Appropriate storage capacity can be provided in the relevant device. The memory can be of any type suitable for the local technical environment and can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Regarding Figure 8 one or more of the steps discussed can be performed by one or more processors in conjunction with one or more memories.

[0212] When loaded or otherwise provided on a suitable data processing apparatus, a suitably adapted computer program code product can be used to implement the embodiments. The program code product for providing the operations can be stored, provided, and implemented via a suitable carrier medium. A suitable computer program can be included on a computer-readable recording medium. It is possible to download the program code product via a data network. Generally, the various embodiments can be implemented using hardware or dedicated circuitry, software, logic, or any combination thereof. Thus, the embodiments of the present invention can be implemented in various components such as integrated circuit modules. The design of integrated circuits is essentially a highly automated process. Sophisticated and powerful software tools can be used to convert a logic-level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0213] Note that while embodiments have been described with respect to certain architectures, similar principles can be applied to other systems. Thus, although certain embodiments are described by way of example with reference to certain exemplary architectures for wireless networks, technologies, and standards above, the embodiments can be applied to any other suitable form of communication system other than those shown and described herein. It should also be noted that different combinations of different embodiments are possible. It should also be noted herein that while exemplary embodiments of the present invention have been described above, several variations and modifications can be made to the disclosed solution without departing from the spirit and scope of the present invention.

Claims

1. A communication method, comprising: Receiving, in at least one first subframe of a burst, at least one downlink transport block whose acknowledgement is required from a base station; Receiving, from the base station, a trigger for a first uplink channel in which the acknowledgement of the at least one downlink transport block will be provided; Preparing the first uplink channel independently of the actual time during which the transmission of the first uplink channel will occur; Transmitting, in a subsequent burst, the prepared first uplink channel with the acknowledgement; Receiving uplink scheduling information from the base station; Preparing a second uplink channel according to the uplink scheduling information received from the base station, wherein the second uplink channel depends on transmission information associated with the uplink scheduling information; And Transmitting, in the subsequent burst, the prepared second uplink channel.

2. The method according to claim 1, wherein the uplink scheduling information is received in at least one downlink control channel.

3. The method according to claim 1 or 2, wherein the transmission of the prepared first uplink channel occurs at a first time offset after receiving the trigger from the base station.

4. The method according to claim 3, wherein the transmission of the prepared second uplink channel occurs at a second time offset after receiving the uplink scheduling information.

5. The method according to claim 4, wherein the first time offset is less than the second time offset.

6. The method according to claim 4, wherein the second time offset comprises x subframes after receiving the uplink scheduling information.

7. The method according to claim 6, wherein x is 4.

8. The method according to claim 1 or 2, wherein for the second uplink channel, at least one of the following depends on the transmission information: reference signal sequence; reference signal cyclic shift; data bit or symbol scrambling; and data bit interleaving.

9. The method according to claim 1 or 2, wherein the transmission information comprises at least one of a subframe number and a time slot number.

10. The method according to claim 1 or 2, wherein at least one of the first uplink channel and the second uplink channel comprises a physical uplink channel.

11. The method according to claim 1 or 2, wherein the first uplink channel is a short PUCCH.

12. The method according to claim 1 or 2, wherein the acknowledgement comprises a hybrid automatic repeat request acknowledgement.

13. A computer program product, comprising program code means which, when the program code is run on a data processing device, is adapted to perform the steps according to any one of the preceding claims.

14. A device for use in a user equipment, the device comprising at least one processor and at least one memory, the at least one memory comprising computer code for one or more programs, the at least one memory and the computer code being configured to, together with the at least one processor, cause the device to at least: Receiving, in at least one first subframe of a burst, at least one downlink transport block for which an acknowledgment is needed from a base station; Receiving, from the base station, a trigger for a first uplink channel in which the acknowledgment of the at least one downlink transport block will be provided; Preparing the first uplink channel independently of the actual time during which the transmission of the first uplink channel will occur; Transmitting, in a subsequent burst, the prepared first uplink channel with the acknowledgment; Receiving uplink scheduling information from the base station; Preparing a second uplink channel according to the uplink scheduling information received from the base station, wherein the second uplink channel depends on transmission information associated with the uplink scheduling information; And Transmitting, in the subsequent burst, the prepared second uplink channel.

15. The apparatus according to claim 14, wherein the at least one memory and the computer code are configured to, together with the at least one processor, cause the apparatus to receive a trigger from the base station, wherein the transmission of the prepared first uplink channel occurs at a first time offset after receiving the trigger from the base station.

16. A communication method, comprising: Transmitting, in at least one first subframe of a burst, at least one downlink transport block for which an acknowledgment is needed from a base station; Sending, from the base station, a trigger for a first uplink channel in which the acknowledgment of the at least one downlink transport block will be provided; Receiving, in a subsequent burst, the first uplink channel with the acknowledgment, wherein the first uplink channel is prepared independently of the actual time during which the transmission of the first uplink channel will occur; Transmitting uplink scheduling information from the base station; And Receiving, in the subsequent burst, a second uplink channel that complies with the uplink scheduling information, wherein the second uplink channel depends on transmission information associated with the uplink scheduling information.

17. An apparatus for use in a user equipment, the apparatus comprising at least one processor and at least one memory, the at least one memory including computer code for one or more programs, the at least one memory and the computer code being configured to, together with the at least one processor, cause the apparatus to at least: Cause the transmission of at least one downlink transport block for which an acknowledgment is needed in at least one first subframe of a burst; Cause the transmission of a trigger for a first uplink channel in which the acknowledgment of the at least one downlink transport block will be provided; Receiving, in a subsequent burst, the first uplink channel with the acknowledgment, wherein the first uplink channel is prepared independently of the actual time during which the transmission of the first uplink channel will occur; Cause the transmission of uplink scheduling information; And Receive a second uplink channel in the subsequent burst, where the second uplink channel conforms to the uplink scheduling information, and where the second uplink channel depends on transmission information associated with the uplink scheduling information.

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