Low power wireless device

Abstract

In accordance with an example aspect of the present disclosure, an apparatus is provided that is configured to receive a configuration that allocates at least two search windows to the apparatus, where each of the at least two search windows includes at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, where the at least one time-frequency resource includes at least one time-frequency resource from the plurality of time-frequency resources in the resource pool. The time-frequency resources of the resource pool are repeatedly reproduced in time according to the period, configuring and defining a starting time-frequency resource and a repetition duration within the resource pool, and receiving a wake-up signal on at least one time-frequency resource.

Description

Technical Field

[0001] The present disclosure relates to transmit and receive arrangements in low power wireless devices. Background Art

[0002] Wireless communication devices can be battery powered, and therefore, optimizing the use of battery power has long been a goal in designing such devices. Minimizing power consumption increases the time a battery lasts before needing to be recharged, which enhances overall system usability by enabling a more diverse set of use cases.

[0003] While personal communication devices such as smartphones can be recharged every few days, there are different types of wireless devices for which frequent recharging is challenging. For example, sensor devices installed in vehicles or buildings may be configured to provide information about liquid flow or temperature readings, or trigger a fire alarm, for example, making them designed to be powered by a stable power source or very long-lasting rechargeable or replaceable batteries. Summary of the Invention

[0004] According to some aspects, the subject matter of the independent claims is provided. Some embodiments are defined in the dependent claims. The scope of protection sought for various embodiments of the present invention is set forth in the independent claims. The embodiments, examples, and features described in this specification that do not fall within the scope of the independent claims (if any) are to be construed as examples that aid in understanding the various embodiments of the present invention.

[0005] According to a first aspect of the present disclosure, a device is provided, comprising at least one processing core and at least one memory storing instructions, wherein the instructions, when executed by the at least one processing core, cause the device to at least receive a configuration for allocating at least two search windows to the device, wherein each of the at least two search windows includes at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, and the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and receives a wake-up signal on the at least one time-frequency resource.

[0006] According to a second aspect of the present disclosure, a device is provided, comprising at least one processing core and at least one memory storing instructions, wherein the instructions, when executed by the at least one processing core, cause the device to at least provide a user equipment with a configuration for allocating at least two search windows to the user equipment, wherein each of the at least two search windows includes at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and uses the at least one time-frequency resource to send a wake-up signal to the user equipment.

[0007] According to a third aspect of the present disclosure, a method is provided, comprising receiving a configuration for allocating at least two search windows to a device, wherein each of the at least two search windows includes at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and receiving a wake-up signal on the at least one time-frequency resource.

[0008] According to a fourth aspect of the present disclosure, a method is provided, comprising providing a configuration for allocating at least two search windows to a user equipment, wherein each of the at least two search windows comprises at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and sending a signal to the user equipment using the at least one time-frequency resource.

[0009] According to a fifth aspect of the present disclosure, a non-transitory computer-readable medium is provided, on which a computer-readable instruction set is stored. When executed by at least one processor, the computer-readable instruction set causes an apparatus to at least receive a configuration for allocating at least two search windows to the apparatus, wherein each of the at least two search windows includes at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, and the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and receives a signal on the at least one time-frequency resource.

[0010] According to a sixth aspect of the present disclosure, a non-transitory computer-readable medium is provided, on which a computer-readable instruction set is stored. When executed by at least one processor, the computer-readable instruction set enables the device to at least provide a user equipment with a configuration for allocating at least two search windows to the user equipment, wherein each of the at least two search windows includes at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, the configuration defines the starting time-frequency resource and the repetition duration within the resource pool, and uses the at least one time-frequency resource to send a signal to the user equipment.

[0011] According to the seventh aspect of the present disclosure, a device is provided, comprising a component for the following operations: receiving a configuration for allocating at least two search windows to the device, wherein each of the at least two search windows includes at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and receiving a wake-up signal on the at least one time-frequency resource.

[0012] According to an eighth aspect of the present disclosure, a device is provided, comprising a component for: providing a configuration for allocating at least two search windows to a user equipment, wherein each of the at least two search windows includes at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and sending a signal to the user equipment using the at least one time-frequency resource.

[0013] According to the ninth aspect of the present disclosure, a device is provided, comprising a component for: storing a configuration for allocating at least one time-frequency resource from a plurality of time-frequency resources in a resource pool to the device, wherein the time-frequency resources of the resource pool are repeated in time according to a pattern, processing a signal received on the at least one allocated time-frequency resource via a wireless receiver included in the device, and switching a wireless transceiver included in the device and different from the wireless receiver from a low-power state to an active state based on reception of the signal, and indicating to a base station node the number of repetitions used in reception of the signal.

[0014] According to a tenth aspect of the present disclosure, a device is provided, comprising a component for: providing a configuration to a user equipment for allocating to the user equipment at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a pattern, sending a signal to the user equipment using the at least one allocated time-frequency resource, the sending comprising repetition of the signal, and receiving a cellular signal from the user equipment after at least one of the repetitions of sending the signal to the user equipment, and receiving an indication of the number of repetitions used to receive the signal at the user equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1A An example system is shown in accordance with at least some embodiments of the present invention;

[0016] Figure 1B An example wireless receiver according to at least some embodiments of the present invention is shown;

[0017] Figure 2A shows resource pools that may be used in at least some embodiments of the present invention;

[0018] Figure 2B shows parallel search windows that may be used in at least some embodiments of the present invention;

[0019] Figure 2C shows adaptive repetition that may be used in at least some embodiments of the present invention;

[0020] Figure 2D is a signaling diagram according to at least some embodiments of the present invention;

[0021] Figure 3 shows example apparatus capable of supporting at least some embodiments of the present invention;

[0022] Figure 4 shows signaling according to at least some embodiments of the present invention, and

[0023] Figure 5 is a flow chart of a method according to at least some embodiments of the present invention. DETAILED DESCRIPTION

[0024] This article describes a wireless wake-up signal that is intended to provide an optimized wake-up signal to a wireless communication device to trigger the wireless communication device to turn on a wireless transceiver that can be used to transmit data. The wireless transceiver can alternately switch from a more reduced activity state to a less reduced activity state. For example, for a device with a lower path loss to a base station node, the wake-up signal can be repeated a fewer number of times, and for a device with a higher path loss to a base station node, the wake-up signal can be repeated a greater number of times. Therefore, the wake-up signal can be provided without wasting energy or frequency / time resources available for the wireless channel or compromising coverage. In principle, a wireless receiver in a wireless communication device configured to receive a wake-up signal can be optimized for very low power consumption, which tends to result in reduced sensitivity in the wireless receiver. The adaptive repetition mechanism described herein provides a solution to the dual challenges of providing a wake-up signal using minimal energy or frequency / time resources and providing sufficient coverage for it.

[0025] Figure 1A An example system according to at least some embodiments of the present invention is shown. A base station node 130, such as a cellular base station 130, is configured to operate based on an appropriate technical standard, such as, for example, Long Term Evolution (LTE), fifth generation (5G), or 6G. A base station may be referred to as a radio node, network node, node, eNode B, eNB, or gNB network device. A base station may include a centralized unit (gNB-CU) and one or more distributed units (gNB-DU). The gNB-CU and gNB-DU may be connected using, for example, an F1 interface. Another term for 5G is New Radio (NR). Yet another example of a suitable technical standard is 5G Advanced. Alternatively, the base station node 130 may be a non-cellular base station node, such as, for example, a wireless local area network (WLAN) or a Worldwide Interoperability for Microwave Access (WiMAX) access point.

[0026] In addition to base station node 130, the system of FIG1 also includes two user equipment (UEs) 110 and 120. A UE may be referred to as a terminal, terminal device, user equipment, or simply a device. UEs 110 and 120 include a wireless transceiver configured to communicate using a cellular or non-cellular radio technology, such as one of those described above, for example, to achieve interoperability with base station node 130. User equipment 110 and 120 may include, for example, an Internet of Things (IoT) node, such as a sensor node, or a utility meter that is not an IoT node. UEs 110 and 120 are shown as including displays, however, this is by no means mandatory, as many UEs suitable for use with the presently disclosed mechanisms are optimized for low power consumption and may lack a visual display entirely. Instead, these UEs may be configured to provide uplink transmissions to base station node 130, for example, upon request or according to a preconfigured schedule for reporting. The uplink transmission may include sensor data generated by the respective UE 110, 120, or mesh network data received from another device in the UE 110, 120, for example, for clarity of illustration. Figure 1A The additional equipment is not shown.

[0027] The UE 110, 120 is configured to spend time in a power saving state when not transmitting or receiving via the radio transceiver. The power saving state includes the radio transceiver of the UE 110, 120 being in a low power state. The low power state of the radio transceiver can be a state in which the radio transceiver is turned off or placed in a sleep or other inactive state in which the radio transceiver does not monitor for incoming transmissions and does not transmit signals. Further examples of names used for sleep or inactive states are discontinuous reception (DRX), sleep state, DRX off state, RRC_Idle, and RRC_Inactive states.

[0028] The power saving state may be extensive and also extend to other systems of the UE 110, 120 besides the wireless transceiver. The UE 110, 120 may be powered by a non-rechargeable battery that is intended to power the UE 110, 120 for several months or even a year, so careful optimization of power consumption is required. In particular, for example, monitoring transmissions using cellular or non-cellular radio technologies such as those described above may necessarily consume too much power to be used in the event of a power outage. Figure 1AIn the UE 110, 120 of the present invention, these radio technologies are not used in the energy-saving state. In order to enable communication with the UE 110, 120 in the energy-saving state, the UE 110, 120 is equipped with a wireless receiver separate from the wireless transceiver, which can be used with cellular or non-cellular technology to receive modulated payload data from the wireless communication system. The base station node 130 can provide a signal that the wireless receiver is configured to detect, such as a wake-up signal. The wireless receiver can be called, for example, a low-power receiver, an ultra-low-power receiver, or a wake-up receiver WUR. In response to the signal, the UE receiving the signal switches its wireless transceiver from the low-power state to an active state. Examples of active states include radio resource control RRC_Active (RRC_Active), DRX on, and DRX active. In the active state, the wireless transceiver is able to receive and / or send information based on the cellular or non-cellular radio technology that the UE is configured to use. Initially in the active state, the device may be in the RRC_Idle state, from which an RRC connection may be established, from which the state is switched to RRC_Connected. The wireless transceiver is the main radio of the user equipment, while the wireless receiver is used to receive signals to exit the power saving state.

[0029] exist Figure 1A In this case, UE 110 has a clearer radio path to base station node 130, and thus, the signal sent from base station node 130 to UE 110 is received with less path loss than the signal sent from base station node 130 to UE 120. Typically, UE 120 can be further away from base station node 130, but this is not necessarily the case, as radio paths can be inherently more complex and include reflections from objects, which result in path loss without necessarily involving large distances. To provide the signal to UE 120, the signal can be sent from base station node 130 using a higher transmit power and / or a greater number of repetitions. The repetitions can occur sequentially in time and / or at least partially in parallel in time using different frequencies. For example, the repetitions can be combined in UE 120 by integrating the on-duration energy and the off-duration energy from not just one transmission, but multiple transmissions. The on-duration is a predefined portion of the transmission containing the signal, while the remainder of the transmission is the off-duration. The off-duration energy can be used, for example, to determine a detection threshold. The base station node 130 may send the first wake-up signal with a minimum repetition estimated to be sufficient for a specific UE or with no repetition.

[0030] Figure 1B An example wireless receiver according to at least some embodiments of the present invention is shown. Figure 1BAn example wireless receiver adapted to receive a wake-up signal from a base station node 130 is shown. A signal, such as one based on on-off keying (OOK) or MC-OOK, is provided from a receive antenna to a bandpass filter 140, then to a low-noise amplifier 150, then to an envelope detector 160, and then to an integrator 170 configured to reset at symbol intervals. Integrator 170 provides its output to a comparator 180, which in turn provides its output to a correlator 190, which detects whether a specific wake-up signal, identified by a wake-up signal identifier (WUS ID), has been detected. If so, and the UE is configured to respond to this specific wake-up signal, a signal 1100 is provided, which turns on the wireless transceiver, which serves as the UE's primary radio, as described above. After envelope detector 160, the signal is a low-frequency signal, low when a 0 is received, or high when a 1 is received. By integrating the signal over each symbol duration, signal noise is suppressed, and comparator 180 can then determine whether the received symbol is a 0 or a 1 by comparing it to the average signal level. Finally, in correlator 190, the detected bit sequence is correlated with the desired signal.

[0031] Figure 1B The advantage of the receiver shown in is that it does not require mixers, analog-to-digital converters, or advanced baseband processing, making it an inherently very power-efficient solution. In practice, such a receiver may be more complex than the one shown, but Figure 1B It is shown that the receiver ideally could be very simple, which is why OOK and multi-carrier OOK, ie MC-OOK, are attractive modulation schemes to choose from when designing a signal to be sent to a wireless receiver.

[0032] On the other hand, Figure 1B A wireless receiver optimized for low power consumption, such as a wireless receiver in a wireless network, typically has worse sensitivity than the UE's primary radio, which may use a cellular or non-cellular radio technology, such as 5G or WiMAX, that employs complex and ingenious solutions to find signals in the noise. However, these solutions consume power. This poses a problem because the UEs 110, 120 may be near the edge of a cell controlled by the base station node 130, and these cells are typically dimensioned based on the expected or required sensitivity of the primary wireless transceiver. Therefore, it may be difficult to provide a wake-up signal to a UE near the edge of a cell, for example, using OOK or MC-OOK, without overusing time / frequency resources.

[0033] This document describes a method that aims to provide benefits in terms of technical effects and reducing the impact of this challenge, wherein resources are allocated to UEs to provide signals to their wireless receivers to selectively trigger activation of the primary radio of the corresponding UE using adaptive repetition of a wake-up signal. This can result in improved and adjustable wake-up signal coverage, reduced resource consumption of the wake-up signal, and / or efficient multiplexing of different UEs / UE groups. Due to the improved wake-up signal coverage, UE battery savings can also be achieved. The base station node 130 can use the resources to send wake-up signals, cellular or non-cellular data unrelated to the wake-up process, or keep the resources unused based on the situation it finds itself in.

[0034] Figure 2A Resource pools that can be used in at least some embodiments of the present invention are shown. In the diagram there are resource pools 201 and 202. Resource pool 201 includes resources 201A and resource pool 202 includes resources 202A. Resources 201A, 202A can be used to transmit self-decodable transmissions, for example using OOK or MC-OOK keying. Self-decodable transmissions can mean that a receiver such as a UE can receive a message or information content based on a single transmission. The message can be, for example, a command for a given UE to switch a wireless transceiver from a low power state to an active state. The resources can be time-frequency resources, which means that each resource can include one or more sets of subcarriers for a set time slot. The resources can at least partially overlap with each other in time. Resource pool 202 starts after resource pool 201 has ended and Figure 2A In the example of FIG, a physical random access channel PRACH opportunity 203 occurs after resource pool 201 ends and before resource pool 202 begins. As an alternative to or in addition to PRACH, other signals may appear between resource pools 201, 202. The time difference between the resource pools may be, for example, tens of milliseconds, such as 20-60 milliseconds. Although illustrated as having four resources, a resource pool may have far more than four resources, for example, there may be 16, 32, 64, or 128 resources in a resource pool. The number of resources in a resource pool does not have to be a power of two, but may be, for example, 300. This statement about the number of resources in a resource pool applies not only to Figure 2A Since resources can be used to transmit self-decodable transmissions, a resource pool comprising N resources can be used to transmit N self-decodable transmissions, i.e., the resource pool can support N self-decodable transmissions. The resources of the resource pool can be repeated in time and / or frequency according to a pattern, for example, the resources can include time slots in the time domain.

[0035] When the resource pool is followed by the PRACH opportunity, such as Figure 2AAs shown in , adaptive repetition can be advantageously employed between resource pools, as will be described below. In some embodiments, there is a paging reception at the UE after the wake-up signal reception and before the PRACH transmission.

[0036] Each resource 201A, 202A can be allocated to a single UE or a group of UEs. Thus, a UE can be configured to monitor one or more of its allocated resources using its radio receiver, which is distinct from its primary radio, when searching for a signal. The radio receiver can be referred to, for example, as a wake-up signal radio receiver to distinguish it from the primary radio. Similarly, each UE or group of UEs can be assigned at least one OOK or MC-OOK sequence, which is a binary sequence. The resource pool repeats with a set periodicity, for example, a resource pool begins at a constant time interval after the previous instance of the resource pool begins.

[0037] In some embodiments, separate resource pool(s) are allocated to separate beamforming beams, synchronization signal block SSB beams, SSB transmission configuration indication SSB TCI, SSB TCI status or SSB index.

[0038] In some embodiments, separate resource pools are associated with the radio conditions of the UEs. For example, different resource pools may be used for UEs with good radio conditions and UEs with degraded radio conditions.

[0039] When a PRACH opportunity follows a resource pool in time, if the expected PRACH signal is not received from the UE after sending a wake-up signal to the UE using a lower power in the resource pool before the PRACH opportunity, the base station node 130 may use a higher transmit power level for the wake-up signal. The base station node 130 may have a transmitter that is capable of selecting a separate transmit power level for the wake-up signal for each resource pool opportunity. However, in some implementations, the transmit power of the base station node 130 is capped, for example, for regulatory reasons, and cannot be increased beyond a fixed limit.

[0040] In the configuration, a configurable search window within a resource pool can be assigned to a UE, for example, when resources are assigned to the UE. The search window can be expressed as starting from a specific resource within the resource pool: 0, 1, ... (N-1), and having a repetition duration of: 1, 2, ... N resources within the resource pool. A predetermined sequence, such as an OOK sequence, can be configured for each resource. Different resources can be configured with the same predefined sequence. In at least some embodiments, it is not only applied to Figure 2A, the UE may be configured to apply multiple (parallel and / or consecutive) search windows within the resource pool. The repetition duration may be the duration from the start of one repetition to the start of the next repetition in the repetition sequence, that is, the repetition duration may be the periodicity of the repetition.

[0041] Figure 2B Parallel search windows that can be used in at least some embodiments of the present invention are shown. On the left, a resource pool 204 is used with search windows D1, D2, D3, and D4, which are selectively monitored using reception hypotheses h4, h3, h2, and h2 as shown. Each reception hypothesis h4, h3, h2, and h1 can search for a corresponding wake-up signal 205 separately, i.e., independently of the other reception hypotheses. In some embodiments, the wake-up signal is sent so that the energy associated with the wake-up signal is found by more than one search window. In such an embodiment, the search windows can be used collaboratively to conclude that a wake-up signal has been detected. When used separately, each search window can be considered to run a separate reception hypothesis about the wake-up signal. The search window covering the maximum amount of repetitions ( Figure 2B h4) in can be considered the most reliable and the UE can operate based on it. Figure 2B In some embodiments, the search windows in the resource pool may be operated in parallel, but they may equally well be configured to operate in a serial manner, such that D1 is evaluated after one resource, D2 is evaluated after two resources, D3 is evaluated after three resources, and D4 is evaluated after four resources. In at least some embodiments, the UE may be configured to apply multiple (parallel and / or serial) search windows within the resource pool.

[0042] Figure 2C 201, 202 and 203 correspond to adaptive repetition that can be used in at least some embodiments of the present invention. Figure 2A. A resource pool can have many more than four resources; for example, there can be 16, 32, 64, or 128 resources in a resource pool. In the following rows, we illustrate how base station node 130 uses resources from resource pools 201 and 202. Time progresses from left to right. For example, initially, during resource pool 201, the first resource is used to transmit a wake-up signal S, while the other resources are used to send data D not related to the wake-up signal, e.g., cellular data such as streaming video content. Because the UE does not detect a wake-up signal in the first resource in this example, during resource pool 202, base station node 130 transmits a wake-up signal in all four resources of the resource pool to give the UE a better chance of detecting the wake-up signal. Base station node 130 can determine that the UE did not receive a wake-up signal from resource pool 201 based on the UE transmission that did not acknowledge the wake-up signal during PRACH opportunity 203. In resource pools 201 and 202, the UE can, for example, monitor for repetitions on the first, first two, or all four resources. In other words, the UE may apply three search windows, one corresponding to only the first resource, one corresponding to only the first two resources, and one corresponding to all four resources.In at least some embodiments, the UE may be configured to apply multiple (parallel and / or sequential) search windows within a resource pool.

[0043] Examples of cellular data include physical downlink control channel (PDCCH) data, physical downlink shared channel (PDSCH) data, demodulation reference signal (DM-RS), channel state information reference signal (CSI-RS), phase tracking reference signal (PTRS), and positioning reference signal (PRS). Thus, dynamic transmission of cellular data via wake-up signal resources can be achieved, such as is available in situations where the cellular data is not urgent. The presence of cellular data in the resource may not be detected by the wake-up signal radio receivers of UEs monitoring the resource, as receiving the cellular data would require the use of the primary radio of those UEs.

[0044] Base station node 130 may transmit the first wake-up signal with the minimum repetition estimated to be sufficient for a specific UE, or with no repetition. Base station node 130 may transmit the wake-up signal with increased repetitions after failing to obtain a response from the UE. Otherwise, base station node 130 may use resources used for cellular data. In other words, base station node 130 may use resources not used in the repetitions of the wake-up signal to transmit cellular data.

[0045] The base station node 130 may use the resources to send a wake-up signal, cellular or non-cellular data not related to the wake-up process, or keep the resources unused based on the situation it finds itself in. This amounts to time division multiplexing of data and wake-up signals within the resources of the resource pool.

[0046] In some embodiments, the base station node 130 is configured to record the number of repetitions after which the UE indicates that it has received the wake-up signal, for example, by transmitting using its primary radio transceiver during a PRACH opportunity, which is turned on in response to the wake-up signal. In other words, the use of a particular PRACH opportunity can be equivalent to an indication of how many repetitions are required to receive the wake-up signal, or equivalent to a UE estimate of how many repetitions are required to receive the wake-up signal. The base station node 130 can then use the recorded number of repetitions of the wake-up signal. This serves to reduce the latency associated with using the wake-up signal, as the correct number of repetitions is used as the first attempt. In many use cases, the UEs awakened using the wake-up signal are relatively stationary, such as those in fixed installations, and therefore their radio path loss to the base station node may be relatively constant, or at least vary only slowly. The base station node 130 can determine the number of repetitions required for the UE based on the PRACH opportunity used by the UE. Specifically, the number of repetitions can be the number of transmissions by the base station node in the resource pool immediately preceding the PRACH opportunity used by the UE. Alternatively, the UE may provide the base station node 130 with its required number of repetitions in other ways using a physical channel different from the PRACH.

[0047] In some embodiments, a UE always transmits in a PRACH opportunity following a resource pool in response to detecting a wake-up signal in an immediately preceding resource pool. In these cases, upon detecting a particular PRACH preamble in a particular opportunity, the base station node can increase or decrease the number of repetitions used for future transmissions of the wake-up signal to that UE or group of UEs.

[0048] The UE may be configured to indicate the number of repetitions it requires, or an estimate of the number of repetitions the UE will require, to detect the wake-up signal also or alternatively using a Channel State Indication (CSI) information element, which is provided to the base station node using the primary radio.

[0049] Base station node 130 may perform OOK or MC-OOK sequence hopping between repetitions or between resources in a resource pool based on the resource position within the repetition cycle, and this may result in improved performance. In other words, the OOK sequence may be changed between repetitions. As an alternative or in addition to changing the OOK sequence, the resources used may also be changed between repetitions.

[0050] Figure 2D is a signaling diagram according to at least some embodiments of the present invention. On the vertical axis, on the left is base station node 130 and on the right is UE 110. Time progresses from top to bottom.

[0051] In phase 210, a configuration is provided to UE 110 for allocating at least one resource from the resource pool to the UE. This may be, for example, a time / frequency definition of the resource. Also, more than one search window configuration is allocated to the UE, as well as information about the wake-up signal that will ultimately be provided to UE 110, such as its periodicity and a sequence such as an OOK sequence. Multiple search windows enable adaptive repetition of the wake-up signal. Phase 210 may be performed using dedicated and / or broadcast signaling. Following phase 210, the UE will attempt to periodically detect the wake-up signal from the resource pool using the multiple search window configurations. The wake-up signal transmission may thus include at least one on-off keying sequence.

[0052] In stage 220, base station node 130 uses the resources allocated in stage 210 to provide a wake-up signal to UE 110. UE 110 determines in stage 230 that a signal has been detected and, in response, activates at least the primary radio transceiver of UE 110 and optionally also other systems of the UE, such as a primary processor. In stage 240, base station node 130 transmits a paging message to UE 110. In stage 250, UE 110 transmits to the base station node, for example, on a PRACH or by providing a low-power channel state information (LP-CSI) message.

[0053] After the timer has expired and no communications are performed using the primary radio transceiver, the UE 110 may be configured to revert to the power save state.

[0054] In a variation of the process shown in 2D, a UE or UE group is configured with multiple wake-up signal sequences to enable multiplexing of wake-up signals by assigning sequences and search window configurations to the UE or UE group. Each UE or UE group is also assigned wake-up signal resources, for example from one to four resources, based on an assumed coverage level or abundance level. When the UE monitors the wake-up signal in the configured resources, the UE assumes that different possible sequences may exist, so that indication of a single UE or UE group or joint indication of multiple UEs or UE groups is possible. When used in the last resource, or only in the resources assigned to the UE or UE group, one sequence can be assigned to indicate the wake-up of only the UE or UE group. Another sequence can be used to indicate possible wake-up of all UEs or UE groups, and further sequences can optionally be used to indicate different possible multiplexing combinations. In one possible implementation of this variation, the sequences assigned to different multiplexing scenarios are Zadoff-Chu sequences with different cyclic shifts of the same root sequence assigned to different multiplexing scenarios. In one possible implementation of this variant, with the known cyclic shift difference, the UE may perform combining of correlation results of multiple wake-up signal repetitions by taking the shift into account in the combining process.

[0055] For example, Figure 2A For resource 201A, the first resource in time may correspond to the monitoring opportunity for all UEs and is the only resource monitored by UEs in the best coverage category (corresponding to the lowest path loss or path loss range to the base station node). This category may be referred to as category A. The first resource triggers wake-up for UEs in category A but not for UEs in other categories. If the first resource is used, subsequent resources may not be used. UEs in other groups may monitor the resource, but do not have to do so. The sequence in the resource triggers wake-up of UEs in category A. The sequence in the first resource may also be part of a wake-up message for UEs in other classes. The sequence in the resource may act as a repetition for UEs in categories B, C, and D discussed below.

[0056] The second resource, which occurs after the first resource and before the third resource, may correspond to a monitoring opportunity for UEs in categories B, C, and D. It is the last resource monitored by UEs in category B, which are UEs with the second lowest path loss to base station node 130. This resource may contain different sequences to distinguish different wake-up signals. For example, a sequence may be included in this resource for category B UEs only to trigger wake-up for category B UEs but not for other categories. If this sequence is used, the third and fourth resources occurring after the second resource may be left empty. Other UE categories C and D do not necessarily need to monitor this sequence. As another example, another sequence may be included in this resource for UE categories B, C, and D to trigger wake-up for category B UEs and notify categories C and D of the possibility of wake-up. Another example is using this resource to transmit a specific sequence for all UE categories except B, so that the possibility of wake-up is conveyed to UE categories other than A and B. UE category B does not need to monitor this specific sequence. Another example of a sequence transmitted on this resource is a possible additional sequence used to further separate other group multiplexing options.

[0057] The third resource that appears after the second resource and before the fourth resource from resource 201A may correspond to a monitoring opportunity for categories C and D, being the last resource monitored by UEs of category C, the category with the third lowest path loss to the base station node. The third resource may contain different sequences to distinguish between different wake-ups. For example, a sequence that is only for category C may be used, which triggers a wake-up for category C but not for category D. If this sequence is used, the following resources may be empty. UE category D does not need to monitor this sequence. As a second example, a sequence may be placed in this resource for categories C and D, triggering a wake-up for category C and indicating the possibility of a wake-up for category D. Finally, a sequence for category D may be placed in this resource as a repeat for UE category D. Category C UEs do not need to monitor this sequence as it is intended for category D UEs.

[0058] Finally, the temporally last fourth resource for class D, for which the UE has the highest path loss to the base station node, may contain a repetition of the wake-up signal sequence for class D. The resource pool may have more than four resources, for example, there may be 16, 32, 64, or 128 resources in the resource pool.

[0059] Figure 3 An example apparatus capable of supporting at least some embodiments of the present invention is shown. Device 300 is shown, which may include, for example Figure 1A UE 110, 120, or, where applicable, base station node 130. Device 300 includes a processor 310, which may include, for example, a single-core or multi-core processor, wherein a single-core processor includes one processing core and a multi-core processor includes more than one processing core. Processor 310 may generally include a control device. Processor 310 may include more than one processor. When processor 310 includes more than one processor, device 300 may be a distributed device, where task processing occurs in more than one physical unit. Processor 310 may be a control device. A processing core may include, for example, a Cortex-A8 processing core manufactured by ARM Holdings or a Zen processing core designed by Advanced Micro Devices. Processor 310 may include at least one Qualcomm Snapdragon and / or Intel Atom processor. Processor 310 may include at least one application-specific integrated circuit (ASIC). Processor 310 may include at least one field-programmable gate array (FPGA). Processor 310 may be a component for executing method steps in device 300, such as storing, processing, switching, receiving, executing, providing, and transmitting. Processor 310 may be configured, at least in part, by computer instructions to perform actions.

[0060] The processor may include circuitry, or be constructed as one or more circuits, configured to perform the stages of the methods according to the embodiments described herein. As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) a hardware-only circuit implementation, such as an implementation in analog and / or digital circuitry only, and (b) a combination of hardware circuitry and software, such as, as applicable: (i) a combination of analog and / or digital hardware circuitry with software / firmware, and (ii) any portion of a hardware processor (including a digital signal processor) with software, software, and memory that work together to enable an apparatus such as a UE or base station node to perform various functions and (c) a hardware circuitry and / or processor, such as a microprocessor or a portion of a microprocessor, that requires software (e.g., firmware) to operate, but may not have software when it is not needed to operate.

[0061] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or networking device.

[0062] Device 300 may include memory 320. Memory 320 may include random access memory and / or permanent memory. Memory 320 may include at least one RAM chip. Memory 320 may include, for example, solid-state, magnetic, optical, and / or holographic memory. Memory 320 may be at least partially accessible to processor 310. Memory 320 may be at least partially included in processor 310. Memory 320 may be a component for storing information. Memory 320 may include computer instructions that processor 310 is configured to execute. When computer instructions configured to cause processor 310 to perform certain actions are stored in memory 320, and device 300 as a whole is configured to operate under the direction of processor 310 using computer instructions from memory 320, processor 310 and / or at least one of its processing cores may be considered to be configured to perform the certain actions. Memory 320 may be at least partially included in processor 310. Memory 320 may be at least partially external to device 300, but accessible to device 300. Memory 320 may be non-transitory. As used herein, the term "non-transitory" is a limitation of the medium itself (ie, tangible, non-signal), not a limitation on the persistence of data storage (eg, RAM versus ROM).

[0063] Device 300 may include a transmitter 330. Device 300 may include a receiver 340. Transmitter 330 and receiver 340 may be configured to transmit and receive information, respectively, in accordance with at least one cellular or non-cellular standard. Transmitter 330 may include more than one transmitter. Receiver 340 may include more than one receiver. For example, transmitter 330 and / or receiver 340 may be configured to operate in accordance with Global System for Mobile Communications (GSM), Wideband Code Division Multiple Access (WCDMA), 5G, Long Term Evolution (LTE), IS-95, Wireless Local Area Network (WLAN), and / or Worldwide Interoperability for Microwave Access (WiMAX) standards. Transmitter 330 and receiver 340 together comprise a wireless transceiver, i.e., the device's primary radio.

[0064] The device 300 may include a wireless receiver 350. The wireless receiver 350 may be configured to receive a wireless wake-up signal using, for example, OOK, MC-OOK, or multi-carrier frequency shift keying (MC-FSK). The wireless receiver 350, which may be referred to as a wake-up signal wireless receiver, may be distinct from the wireless transceivers 330 and 340. Figure 1B An exemplary architecture of a wireless receiver 350 is shown in FIG.

[0065] Device 300 may include a user interface UI 360. UI 360 may include at least one of a display, a keyboard, a touch screen, a vibrator arranged to signal the user by vibrating device 300, a speaker, and a microphone. The user can operate device 300 via UI 360, for example, to accept an incoming phone call, initiate a phone call or video call, browse the Internet, manage digital files stored in memory 320 or on a cloud accessible via transmitter 330 and receiver 340 or via NFC transceiver 350, and / or play games.

[0066] Device 300 may include or be arranged to accept a user identity module 370. User identity module 370 may include, for example, a subscriber identity module (SIM) card that may be installed in device 300. User identity module 370 may include information identifying a subscription of a user of device 300. User identity module 370 may include encryption information that may be used to verify the identity of the user of device 300 and / or facilitate encryption of transmitted information and billing of the user of device 300 for communications accomplished via device 300.

[0067] Processor 310 may be equipped with a transmitter that is arranged to output information from processor 310 to other devices included in device 300 via electrical leads within device 300. Such a transmitter may include a serial bus transmitter, which is arranged to output information to memory 320 via at least one electrical lead for storage therein. As an alternative to a serial bus, the transmitter may include a parallel bus transmitter. Similarly, processor 310 may include a receiver that is arranged to receive information from processor 310 via electrical leads within device 300 from other devices included in device 300. Such a receiver may include a serial bus receiver, which is arranged to receive information from receiver 340 via at least one electrical lead for processing in processor 310. As an alternative to a serial bus, the receiver may include a parallel bus receiver.

[0068] The device 300 may include Figure 3 3. Device 300 may include additional devices not shown. For example, if device 300 comprises a smartphone, it may include at least one digital camera. Some devices 300 may include a back-facing camera and a front-facing camera, where the back-facing camera may be intended for digital photography and the front-facing camera may be intended for video calling. Device 300 may include a fingerprint sensor, which is arranged to at least partially authenticate a user of device 300. In some embodiments, device 300 lacks at least one of the aforementioned devices.

[0069] The processor 310, memory 320, transmitter 330, receiver 340, wireless receiver 350, UI 360, and / or user identity module 370 can be interconnected in a variety of different ways via electrical leads within the device 300. For example, each of the above devices can be separately connected to a main bus within the device 300 to allow the devices to exchange information. However, as will be understood by those skilled in the art, this is merely an example, and various ways of interconnecting at least two of the above devices can be selected according to the embodiment without departing from the scope of the present invention.

[0070] Figure 4 is a flow chart of a method according to at least some embodiments of the present invention.The stages of the method shown may be performed in an apparatus such as UE 110 or 120, or in a control apparatus configured to control its functions when installed therein.

[0071] Stage 410 includes receiving a configuration for allocating at least two search windows to the apparatus, wherein each of the at least two search windows includes at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool recur repeatedly in time according to a period, and wherein the configuration defines a starting time-frequency resource within the resource pool and a recurrence duration. Stage 420 includes receiving a wake-up signal on the at least one time-frequency resource.

[0072] The base station node 130 may use the resources to transmit a wake-up signal, cellular or non-cellular data unrelated to the wake-up process, or leave the resources unused, based on the situation it finds itself in. The base station node 130 may receive a cellular signal from the user equipment after transmitting at least one repetition of the signal to the user equipment, and receive an indication of the number of repetitions used in receiving the signal at the user equipment.

[0073] Figure 5 is a flow chart of a method according to at least some embodiments of the present invention.The stages of the method shown may be performed in the base station node 130, or in a control device configured to control its functions when installed therein.

[0074] Stage 510 includes providing a configuration to a user equipment for allocating at least two search windows to the user equipment, wherein each of the at least two search windows includes at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool recur repeatedly in time according to a period, and wherein the configuration defines a starting time-frequency resource and a recurrence duration within the resource pool. Stage 520 includes transmitting a signal to the user equipment using the at least one time-frequency resource.

[0075] In some embodiments, the user equipment is configured to store a configuration for allocating at least one time-frequency resource from a plurality of time-frequency resources in a resource pool to the device, wherein the time-frequency resources of the resource pool recur repeatedly in time according to a pattern, process a signal received on at least one allocated time-frequency resource via a wireless receiver included in the device, and based on the reception of the signal, switch a wireless transceiver included in the device and different from the wireless receiver from a low-power state to an active state, and indicate to a base station node the number of repetitions used in the reception of the signal.

[0076] It should be understood that the embodiments of the invention disclosed herein are not limited to the specific structures, processing steps or materials disclosed herein, but extend to equivalents thereof, as will be recognized by those skilled in the relevant art. It should also be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting.

[0077] Reference throughout this specification to an embodiment or embodiments means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" throughout this specification are not necessarily all referring to the same embodiment. Where terms such as "approximately" or "substantially" are used to refer to values, the exact value is disclosed.

[0078] As used herein, for convenience, multiple items, structural elements, constituent elements and / or materials can be presented in a common list. However, these lists should be interpreted as if each member of the list is individually identified as a separate and unique member. Therefore, in the absence of contrary instructions, any single member in such a list should not be interpreted as the de facto equivalent of any other member in the same list based solely on their appearance in a common group. In addition, various embodiments and examples of the present invention can be cited in this article together with the replacement of its various components. It should be understood that these embodiments, examples and alternatives should not be interpreted as actual equivalents of each other, but should be considered as separate and autonomous representations of the present invention.

[0079] In addition, the described features, structures or characteristics can be combined in any suitable manner in one or more embodiments. In the foregoing description, many specific details, such as examples of lengths, widths, shapes, etc., are provided to provide a thorough understanding of the embodiments of the present invention. However, those skilled in the relevant art will recognize that the present invention can be practiced without one or more of the specific details, or using other methods, components, materials, etc. In other cases, well-known structures, materials or operations are not shown or described in detail to avoid obscuring aspects of the present invention.

[0080] Although the above examples illustrate the principles of the present invention in one or more specific applications, it will be apparent to those skilled in the art that many modifications can be made in form, use, and implementation details without requiring creative effort and without departing from the principles and concepts of the present invention. Therefore, it is not intended that the present invention be limited except by the claims set forth below.

[0081] The verbs "to comprise" and "to include" are used in this document as open limitations that neither exclude nor require the presence of unrecited features. The features recited in the dependent claims are mutually freely combinable unless expressly stated otherwise. Furthermore, it should be understood that the use of "a" or "an" throughout this document, i.e., the singular, does not exclude a plurality.

[0082] Industrial Applicability

[0083] At least some embodiments of the present invention find industrial application in managing wireless communications.

Claims

1. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus to at least: receiving a configuration for allocating at least two search windows to the apparatus, wherein: Each of the at least two search windows comprises at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and A wake-up signal is received on the at least one time-frequency resource.

2. The device according to claim 1, wherein The resource pool includes N time-frequency resources supporting N self-decodable wake-up signal transmissions, and the configuration allocates at least one on-off keying sequence to the device, where N is a positive integer.

3. The device according to claim 1 or 2, wherein: The apparatus is configured to receive the wake-up signal by combining energy received in more than one transmission of the wake-up signal and to transmit using a physical random access channel before expiration of the period after the signal has been received in the apparatus.

4. The device according to any one of claims 1 to 3, wherein: The apparatus is configured to receive cellular data using at least one second time-frequency resource from the plurality of time-frequency resources in the resource pool.

5. The device according to any one of claims 1 to 4, wherein: The at least two search windows are in parallel or in succession.

6. The device according to claim 5, wherein The apparatus is further configured to make a plurality of attempts to receive the wake-up signal based on the at least two search windows.

7. The device according to any one of claims 1 to 6, wherein: The configuration defines sequence hopping between repetitions or between the time-frequency resources of the resource pool according to resource positions within the period.

8. The device according to any one of claims 1 to 7, wherein: The configuration defines that more than one time-frequency resources are used for receiving the wake-up signal, and the apparatus is configured to receive repetitions of the wake-up signal using the more than one time-frequency resources.

9. The device according to any one of claims 1 to 8, wherein: The apparatus is configured to indicate to a base station node a number of repetitions used in reception of the wake-up signal or required for successful reception of the wake-up signal.

10. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus to at least: A configuration for allocating at least two search windows to the user equipment is provided to the user equipment, wherein: Each of the at least two search windows comprises at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and A wake-up signal is sent to the user equipment using the at least one time-frequency resource.

11. The device according to claim 10, wherein The apparatus is further configured to increase a number of repetitions of the wake-up signal in subsequent recurrences of the time-frequency resources in the resource pool based on a failure to receive a response to the wake-up signal from the user equipment.

12. A method comprising: receiving a configuration for allocating at least two search windows to an apparatus, wherein each of the at least two search windows comprises at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool repetitively recur in time according to a period, the configuration defining a starting time-frequency resource and a repetition duration within the resource pool, and A wake-up signal is received on the at least one time-frequency resource.

13. A method comprising: providing a configuration to a user equipment for allocating at least two search windows to the user equipment, wherein each of the at least two search windows comprises at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool repetitively recur in time according to a period, the configuration defining a starting time-frequency resource and a repetition duration within the resource pool, and A signal is sent to the user equipment using the at least one time-frequency resource.

14. A non-transitory computer-readable medium having stored thereon a set of computer-readable instructions that, when executed by at least one processor, cause an apparatus to at least: receiving a configuration for allocating at least two search windows to the apparatus, wherein: Each of the at least two search windows comprises at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and A signal is received on the at least one time-frequency resource.

15. A non-transitory computer-readable medium having stored thereon a set of computer-readable instructions that, when executed by at least one processor, cause an apparatus to at least: Providing a configuration for allocating at least two search windows to a user equipment, wherein: Each of the at least two search windows comprises at least one time-frequency resource from a plurality of time-frequency resources in a resource pool, wherein the time-frequency resources of the resource pool are repeatedly reproduced in time according to a period, the configuration defines a starting time-frequency resource and a repetition duration within the resource pool, and A signal is sent to the user equipment using the at least one time-frequency resource.

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