Using OOK modulation and coding to form LP-WUS payload for sequence-based detectors to provide time domain efficiency improvements

Abstract

A UE receives a WUS payload having a modulation superposition sequence superimposed on a code for OOK, where the modulation superposition sequence is formed from a superposition sequence modulated with symbols from a constellation to map information bits to the symbols. The information bits are at least a portion of the WUS payload. The UE determines a constant phase error that corresponds to the ON duration of the OOK and separates the received symbols in phase. The UE uses at least a constant phase error to determine respective received symbols corresponding to respective ON durations of the OOK. The UE determines symbols for modulating the superposition sequence based on the respective received symbols. The UE determines information bits corresponding to the determined symbols, and determines at least one result based on the information bits.

Description

Technical Field

[0001] Examples of embodiments herein relate generally to wireless communications, and more particularly to wake-up signals. Background Art

[0002] In wireless communications, power usage is important for devices that rely on batteries. One piece of hardware that can be put into low-power mode (including shutting down) is the primary radio. However, placing the primary radio in low-power mode means the device cannot receive any signals, including critical signals such as paging signals, so the device is unaware that data is waiting for it.

[0003] To help with this, some devices use LR (Low Power Wake-up Radio LP-WUR), which combines a main radio and an ultra-low power wake-up receiver. The main radio can be placed in low power mode while the ultra-low power wake-up receiver listens for a wake-up signal (WUS). If the ultra-low power wake-up receiver determines that it has received a WUS indicating that the main radio should wake up, the ultra-low power wake-up receiver can trigger the main radio to wake up.

[0004] WUS can take different forms, but one form used involves on-off keying (OOK), which is a type of amplitude shift keying because it relies on the amplitude of the signal (e.g., some amplitude during the ON duration and no amplitude during the OFF duration). One type of OOK is Manchester coding (MC).

[0005] While WUS and the corresponding energy-saving modes are beneficial, these can also be improved. Summary of the Invention

[0006] This section is intended to include examples and is not intended to be limiting.

[0007] In an exemplary embodiment, a method is disclosed, comprising: receiving a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed by a superposition sequence modulated with symbols from a constellation to map information bits to symbols, wherein the information bits are at least a portion of the wake-up signal payload; determining a constant phase error corresponding to an on-duration of the on-off keying and separating received symbols in phase; determining respective received symbols corresponding to respective on-durations of the on-off keying using at least the constant phase error; determining symbols for the modulated superposition sequence based on the respective received symbols; determining information bits corresponding to the determined symbols; and determining at least one result based on the information bits. The method may be performed by a user device.

[0008] Another exemplary embodiment includes a computer program comprising instructions for performing the method of the previous paragraph when the computer program is executed on a device. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium carrying instructions embodied therein for use with the device. Another example is the computer program according to this paragraph, wherein the program is directly loadable into the internal memory of the device.

[0009] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus to at least: receive a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed by a superposition sequence modulated with symbols from a constellation to map information bits to symbols, wherein the information bits are at least a portion of the wake-up signal payload; determine a constant phase error corresponding to an on-duration of on-off keying and separating received symbols in phase; determine respective received symbols corresponding to respective on-durations of on-off keying using at least the constant phase error; determine symbols for the modulated superposition sequence based on the respective received symbols; determine information bits corresponding to the determined symbols; and determine at least one result based on the information bits. The apparatus may be or include user equipment.

[0010] The apparatus according to the preceding paragraph, wherein: determining a constant phase error comprises: performing correlation using a superimposed sequence of a first ON duration from on-off keying to determine a received sequence having a plurality of indices corresponding to respective samples; selecting an index having a maximum value from the received sequence from the plurality of indices; determining a phase using samples corresponding to the index; at least using the phase to determine a first received symbol from the first ON duration; decoding information within a second ON duration of on-off keying to determine a constant phase error; determining respective received symbols using at least the constant phase error comprises: determining respective received symbols using at least the constant phase error for a third ON duration and subsequent ON durations. The apparatus according to this paragraph, wherein the first received symbol is x0 having M bits, requiring 2 M ON duration to estimate the value of x0, and another 2 M The ones digit is used to estimate the constant phase.

[0011] An apparatus as described in the preceding paragraphs, wherein the information decoded during the second ON duration is based on h×h * ≈|h| 2 , using the channel h in the equation for the first received symbol and the second received symbol within the second ON duration, a scaling factor is determined, and the scaling factor is used in decoding the information.

[0012] The apparatus as described above, wherein: the first ON duration of the on-off keying includes a pilot symbol; and determining the constant phase error includes determining the constant phase error based on the pilot symbol.

[0013] An apparatus as described above, wherein the symbols from the constellation include a first symbol, wherein the wake-up signal payload is received during the ON duration of on-off keying, wherein a second symbol of the superimposed sequence is modulated on symbols {0, ..., m} given by: x0 = s0, x1 = s0 × s1, ..., where x0, x1, ..., and x m is the second symbol, and s0, s1, ..., and s m is the first symbol, and the ON duration sequence transmitted at symbol m is given by {z}×x m is given by , where {z} is the superposition sequence.

[0014] The apparatus as described above, wherein each modulated superposition sequence is transmitted with a repetition factor of 2. The apparatus as described above, wherein the encoding for on-off keying comprises Manchester encoding, wherein a first value of a bit is encoded using an ON duration that includes a portion of the modulated superposition sequence, the ON duration being preceded by a null OFF duration, and a second value of the bit is encoded using a null OFF duration that is preceded by an ON duration that includes another portion of the modulated superposition sequence.

[0015] An apparatus as described above, wherein the constellation is from a family of phase modulation schemes. An apparatus as described above, wherein the code used for on-off keying encodes a group of bits, and the symbol used to modulate the superimposed sequence encodes the same group of bits.

[0016] An exemplary computer program product includes a computer-readable storage medium carrying instructions that, when executed by an apparatus, cause the apparatus to at least: receive a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed by a superposition sequence modulated with symbols from a constellation to map information bits to symbols, wherein the information bits are at least a portion of the wake-up signal payload; determine a constant phase error corresponding to an on-duration of the on-off keying and separating the received symbols in phase; determine respective received symbols corresponding to respective on-durations of the on-off keying using at least the constant phase error; determine symbols for the modulated superposition sequence based on the respective received symbols; determine information bits corresponding to the determined symbols; and determine at least one result based on the information bits. The computer program product may be implemented in a user device.

[0017] In another exemplary embodiment, an apparatus includes means for: receiving a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed by a superposition sequence modulated with symbols from a constellation to map information bits to symbols, wherein the information bits are at least a portion of the wake-up signal payload; determining, by a user equipment, a constant phase error corresponding to an on-duration of the on-off keying and separating received symbols in phase; determining respective received symbols corresponding to respective on-durations of the on-off keying using at least the constant phase error; determining symbols for the modulated superposition sequence based on the respective received symbols; determining information bits corresponding to the determined symbols; and determining at least one result based on the information bits. The apparatus may be or include a user equipment.

[0018] In an exemplary embodiment, a method is disclosed, comprising: mapping information bits to symbols, wherein the information bits are at least a portion of a wake-up signal payload; superimposing, by an access node, a modulation superposition sequence on a code for on-off keying to form the wake-up signal payload; and sending, by the access node, the wake-up signal payload to a user equipment.

[0019] Another exemplary embodiment includes a computer program comprising instructions for performing the method of the previous paragraph when the computer program is executed on a device. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium carrying instructions embodied therein for use with the device. Another example is the computer program according to this paragraph, wherein the program is directly loadable into the internal memory of the device.

[0020] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus to at least perform: mapping information bits to symbols, wherein the information bits are at least a portion of a wake-up signal payload; superimposing a modulation superposition sequence on a code for on-off keying to form a wake-up signal payload; and transmitting the wake-up signal payload to a user equipment.

[0021] An exemplary computer program product includes a computer-readable storage medium carrying instructions that, when executed by an apparatus, cause the apparatus to at least perform: mapping information bits to symbols, wherein the information bits are at least a portion of a wake-up signal payload; superimposing a modulation superposition sequence on a code for on-off keying to form a wake-up signal payload; and transmitting the wake-up signal payload to a user equipment.

[0022] In another exemplary embodiment, an apparatus includes means for mapping information bits to symbols, wherein the information bits are at least a portion of a wake-up signal payload; superimposing a modulation superposition sequence on a code for on-off keying to form the wake-up signal payload; and transmitting the wake-up signal payload to a user equipment.

[0023] In an exemplary embodiment, a method is disclosed, the method comprising: receiving a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed by a superposition sequence modulated with symbols from a constellation to map information bits to symbols, wherein the information bits are at least a portion of the wake-up signal payload; decoding the symbols by a user device to determine the information bits; and determining, by the user device, at least one result based on the information bits.

[0024] Another exemplary embodiment includes a computer program comprising instructions for performing the method of the previous paragraph when the computer program is executed on a device. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium carrying instructions embodied therein for use with the device. Another example is the computer program according to this paragraph, wherein the program is directly loadable into the internal memory of the device.

[0025] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus to at least perform: receiving a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed by a superposition sequence modulated with symbols from a constellation to map information bits to symbols, wherein the information bits are at least a portion of the wake-up signal payload; decoding the symbols to determine the information bits; and determining at least one result based on the information bits.

[0026] An exemplary computer program product includes a computer-readable storage medium carrying instructions that, when executed by an apparatus, cause the apparatus to at least perform: receiving a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed by a superposition sequence modulated with symbols from a constellation to map information bits to symbols, wherein the information bits are at least a portion of the wake-up signal payload; decoding the symbols to determine the information bits; and determining at least one result based on the information bits.

[0027] In another exemplary embodiment, an apparatus includes means for receiving a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed by a superposition sequence modulated with symbols from a constellation to map information bits to symbols, wherein the information bits are at least a portion of the wake-up signal payload; decoding the symbols to determine the information bits; and determining at least one result based on the information bits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Reference numerals are used in the drawings, where the same reference numerals may be used to refer to the same components, but the components with the same reference numerals may differ in operation and assembly. In the drawings:

[0029] Figure 1A illustrates UE operation when LR (Low Power Wake-up Radio LP-WUR) is in the OFF state;

[0030] Figure 1B The diagram illustrates the UE operation when the LR is in the on state;

[0031] Figure 2 The superimposed sequence type (e.g., sequence-based information) is illustrated;

[0032] Figure 3 is a flow chart performed by an access node for forming an LP-WUS payload for a sequence-based detector using OOK modulation and coding;

[0033] Figure 4 is a flow chart executed by a user equipment for decoding and using an LP-WUS payload formed using modulation and coding with OOK;

[0034] Figure 5A illustrates information bits conveyed via MC (Manchester) coding for an OOK-based ED (Envelope Detection) receiver for pilot-less transmission;

[0035] Figure 5B illustrates information bits conveyed via MC encoding for pilot-assisted transmission for an OOK-based ED receiver;

[0036] Figure 6 Two sequences are shown for carrying more bits during the ON duration; and

[0037] Figure 7 is a block diagram of one possible non-limiting exemplary system in which exemplary embodiments may be practiced. DETAILED DESCRIPTION

[0038] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred over other embodiments. All embodiments described in this detailed description are exemplary embodiments intended to enable those skilled in the art to make or use these examples.

[0039] Generally in this specification, when more than one figure reference numeral, word or abbreviation with “ / ” is used in this specification, “ / ” may be interpreted as “or”, “and” or “both”. As used herein, “at least one of the following: ” and “at least one of ” and similar expressions (wherein a list of two or more elements is joined by “and” or “or”) mean at least any one of these elements, or at least any two or more of these elements, or at least all of these elements.

[0040] As used herein, unless the context clearly indicates otherwise, the singular forms "a," "an," and "the" also include the plural forms. It is further understood that the terms "comprises," "comprising," "has," "having," "includes," and / or "including" when used herein specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0041] Note that uppercase and lowercase words or phrases are considered the same in this article. For example, the word Slice and Slice are the same, and the phrases Network Repository Function and network repository function are also the same.

[0042] Any flow chart herein (such as Figure 3 and Figure 4 ) or signaling diagrams are considered logical flow diagrams and illustrate the operation of exemplary methods in accordance with exemplary embodiments, the result of execution of computer program instructions embodied on a computer readable memory, the functions performed by hardware implemented logic, and / or the interconnected components for performing the functions. Figure 1A 、 Figure 1B and Figure 7) also illustrate the operation of exemplary methods, the results of execution of computer program instructions embodied on a computer readable memory, functions performed by hardware implemented logic, and / or interconnected components for performing the functions in accordance with exemplary embodiments. For methods, flow charts, and signal diagrams, the order of method steps, blocks in the flow, or signals is not critical but is an example.

[0043] Before proceeding with the examples presented in this article, some information about the relevant technical field is provided. There is a research project (RP-213645, Vivo, "New SID: Study of Low-Power Wake-up Signals and Receivers for NR," 3GPP (3rd Generation Partnership Project) TSG (Technical Services Group) RAN (Radio Access Network) Meeting #94e, Electronic Conference, December 6-17, 2021) on low-power wake-up signals (WUS) and receivers for NR (New Radio). This study (which has now been completed within RAN1) considers the use of a separate low-power wake-up receiver at the UE and evaluates how to reduce UE power consumption. The goal is that the UE's main radio can be in sleep mode (or even powered off) to save power and only activated upon receiving a wake-up signal from the network. Essentially, the network triggers a UE wake-up when needed in an event-driven manner by sending a special WUS to the UE, which is monitored by a dedicated low-power WUS receiver at the UE. When the UE receives the WUS, the WUS receiver triggers the normal NR transceiver to wake up, and communication can begin. Thus, the ultra-low power receiver wakes up the main radio, which otherwise shuts down or remains in deep sleep mode.

[0044] refer to Figure 1A , which illustrates the operation of the UE when the LR (Low Power Wake-up Radio LP-WUR) 150 is in the off state. The LR 150 includes the main radio 120 and the ultra-low power wake-up receiver 130. The UE 10 receives the WUS 110 with the off signal, and the ultra-low power wake-up receiver 130 does not send a signal over the link 125. Then, the main radio 120 is in the off state 140-1, also known as the deep sleep state. Figure 1B In the example embodiment, the WUS 110 has an ON signal, which the ultra low power wake-up receiver 130 receives and outputs a trigger on the link 125. This causes the primary radio 120 to enter the ON state 140-2. Figure 1A and Figure 1B It is a modified version of RWS-210168 (vivo et al., “Motivation for a New Study Item on Ultra-Low Power Wake-up Signaling in Rel-18,” 3GPP TSG RAN Rel-18 Workshop, Electronic Conference, June 28–July 2, 2012).

[0045] It is assumed that the low power wake-up receiver 150 can operate in an always-on mode with very low power consumption. In fact, by designing a simple (WUS) signal and monitoring it with dedicated hardware that can only receive WUS, it is expected that the receiver 150 will consume less power than the NR transceiver.

[0046] LP-WUS is currently being considered for both IDLE / INACTIVE mode and Connected mode. Current discussions are primarily focused on DL (downlink) reception, where LP-WUS can be used to wake up the primary radio to receive PDCCH / PDSCH (Physical Downlink Control Channel / Physical Downlink Shared Channel), such as for paging or other data.

[0047] In RAN1 discussions regarding possible LP-WUS content and LP-SS (Low Power Synchronization Signal) design, the following features are being considered in the study item (R1-2308414, Nordic Semiconductor ASA, "Summary of Discussions on L1 Signal Design and Procedures for Low Power WUS," 3GPP TSG RAN WG1 #114, Toulouse, France, August 21–25, 2023). For more information, see the latest (draft) version of the study item (TR, RP-231814, "TR 38.869 v1.0.0 NR Low Power Wake-up Signal and Receiver Study," CMCC Rapporteur (vivo)). Also see the RAN#108 Rel-19 work item for LP-WUS (RP-234056). For more information, see the latest (draft) version of the study item (TR, RP-231814, "TR 38.869 v1.0.0 NR Low Power Wake-up Signal and Receiver Study," CMCC Rapporteur (vivo)). In RAN#108, a Rel-19 work item (RP-234056) for LP-WUS was agreed upon and it is clear that there is a lot of discussion in this area.

[0048] Since LR is designed to reduce power, the LP-WUS design primarily uses on-off keying (OOK) to converge to the waveform, with or without an embedded sequence. OOK is a modulation scheme in which there is no data / signal during the transmission of one logic state (e.g., logic 0); conversely, data / signal is sent during the transmission of another logic state (e.g., logic 1). In order to integrate the OOK signal in the OFDM (Orthogonal Frequency Division Multiplexing) framework to minimize the impact on legacy UEs, the OOK scheme follows the OFDM symbol structure and generation. Since the OOK scheme performs poorly in low S(I)NR cell edge situations (e.g., the signal is close to noise), an additional sequence can be embedded in the ON duration of the OOK signal to ensure coverage of OOK receivers with additional sequence detection capabilities.

[0049] Despite limiting the use of power-consuming receiver blocks in the LR, the LR may not be able to continuously monitor the LP-WUS at all times, as energy consumption is proportional to the ON duration. Therefore, for efficient operation, the LR is operated in a duty-cycled manner, where it is turned on at discrete moments to reduce power consumption.

[0050] Consider the following situation. Two variables are introduced, namely N osq and N slice , where N osq The number of superimposed sequences corresponding to the time slice ON duration, N slice is the number of time slices made within the ON duration to be interpreted as separate sequences (i.e., segments within the ON duration). Superposition is a sequence applied within the ON duration to spread the energy over the entire BW (bandwidth), making the signal robust to fading. The superposition sequence can be a sequence with a length (e.g., number of samples) corresponding to the ON duration. There are N slice , and each slice has a sequence p, j, ..., q. Each sequence has N osq covering sequences. Therefore, according to N osq and N slice , you can use Figure 2 To characterize the three schemes, we will now describe carrying information during the OOK ON duration. Figure 2 The diagram shows superimposed sequence types (e.g., sequence-based information) and the possibility of multiplexing sequences within the ON duration that can be used to convey information bits. osq sequences 210, and these sequences are used for the left side 220, where the bit "0" (zero) is encoded using Manchester encoding, so there are N bits in the ON duration 240. slices, but there is no sequence transmission during the OFF duration 240. On the right side 230, there is a bit "1" encoded using Manchester encoding, where there is no sequence transmission during the OFF duration 250, but there is a sequence transmission during the On duration 240. No sequence transmission indicates N slice Will be empty during the OFF duration 250. Manchester encoding is an encoding in which the encoding of each data bit is either low then high or high then low for equal times, such as Figure 2 As shown. In general, there is a mapping between logical 1 and logical 0, mapping to bit sequences that are complementary to each other. Note that if desired, the bit mapping can be reversed, and the bit on the left 220 can be bit "1" and the bit on the right 230 can be bit "0".

[0051] The variable M, which is widely used in the LP-WUS study project, refers to the equivalent NR CP-OFDM (Cyclic Prefix Orthogonal Frequency Division Multiplexing) symbol duration (i.e., T symb ), i.e., ON / OFF. Therefore, M=2 represents two possible levels, i.e., in the case of MC (Manchester) coding, this can be packed into {ON, OFF}, {OFF, ON}, otherwise, it can also be packed into {ON, ON}, {OFF, OFF}.

[0052] Three options are described below: cell-specific coverage sequence, i.e., N slice =1 and N osq =1; multiple sequences within the ON duration carry more bits, i.e. N slice =1 and N osq >1; and multiple time slices carrying more information within the ON duration, i.e., N slice >1 and N osq >1.

[0053] Now we describe the cell-specific coverage sequence, N slice =1 and N osq = 1. In this scheme, the sequence is used only to improve the coverage of LP-WUS detection. That is, the sequence used during the ON duration is the same across all ON durations of LP-WUS transmissions. Therefore, a SD-based (sequence detection or sequence detector) receiver can correlate with the same sequence and determine the peak during each ON duration while evaluating the zero during the OFF duration, as the OFF duration contains only receiver noise. This makes SD-based LR simple and can only be triggered when ED mode encounters coverage issues. This scheme has the following benefits, as shown below.

[0054] 1) Since the superposition sequence is based on the cell id (cell identity) or is cell specific, the sequence correlation is simple at the LR, i.e., the LR expects a peak at each ON duration of the OOK transmission.

[0055] 2) Since the entire ON duration is used for sequence transmission, the correlation gain and coverage may vary depending on the OOK sequence modulation order M. When M=1, the LP-WUS signal can have the best coverage.

[0056] 3) This approach is beneficial for dual-mode LR, where ED is used when signal conditions are good, but when signal quality deteriorates, SD mode can be used to improve coverage.

[0057] However, it also has some drawbacks. Specifically, because the ON duration carries the superposition sequence, the information transmitted to an OOK-based receiver is typically very long. Therefore, using the superposition sequence only during the ON duration may cause the LR to switch to SD to perform correlation for the entire LP-WUS duration, which is intended for ED. This approach may also significantly increase the power consumption of SD-based LRs.

[0058] Because the ON duration carries the superposition sequence, the information transmitted for an OOK-based receiver is typically very long. Therefore, using the superposition sequence only during the ON duration may cause the SD to perform correlation for the entire LP-WUS duration, which is for the ED. This significantly increases the power consumption of the SD-based LR.

[0059] Now we describe multiple sequences that carry more bits during the ON duration, namely N slice =1 and N osq >1. In the second option, multiple sequences can be allocated to carry more than one bit of information, i.e., using N osq Covering sequence, can convey log2N osq bits, depending on the sequence used for transmission. The size of the sequence remains the same as the size of the OOK ON duration, that is, N symb / M. The following are the advantages of this approach, namely:

[0060] 1) The number of superposition sequences can be configured based on the number of bits carried in each OOK ON duration.

[0061] 2) As the OOK modulation order increases, the number of samples in the ON duration decreases, so it is difficult to find a better N with cross-correlation characteristics. osqsequence set. That is, even if this increases the data rate, the superposition sequence length will be reduced by the same factor. Therefore, the sequence orthogonality will be reduced, and the number of such orthogonal sequences is limited and also reduced by the same factor.

[0062] 3) Since multiple bits can be conveyed within each ON duration of the LP-WUS, the sequence detector may not be active for a complete LP-WUS transmission. Therefore, the SD can receive fewer ON durations of the LP-WUS signal to recover the complete message carried by the entire LP-WUS, thereby reducing the power consumption of the SD-based receiver.

[0063] Unlike previous approaches, this approach has fewer drawbacks, namely the following: As the number of sequences used for correlation increases with the number of bits carried per ON duration of the LP-WUS, hardware and processing complexity increase exponentially. Furthermore, SD-based receivers may require buffering if processing power does not meet the real-time requirements for sequence detection.

[0064] Now we describe multiple time slices that carry more information within the ON duration, namely N slice >1 and N osq >1. Figure 2 The third option discussed in [1] uses only two sequences, N osq =2 to ensure better cross-correlation performance. However, by multiplexing N osq sequence, i.e. N slice The ON durations are generated by concatenating the sequences corresponding to the corresponding bits in the time domain and then performing an OOK4-style generation. It is worth noting that the length of the sequence scales with the number of information bits carried in each ON duration, i.e., if N s is the number of samples within the ON duration of the OOK signal, then That is, it scales with the number of time segments within each ON duration. Although this can reduce the active time of SD-based LR, the performance advantage is significantly limited by the correlation gain, which is proportional to the sequence length.

[0065] Now that an overview of the technical areas has been provided, the problems in these areas have been described. SD-based receivers will have both I and Q branches and can perform coherent detection, so these receivers inherently have better performance than envelope detectors. It was agreed in the Rel. 19 Work Item Description (WID) that, at least for LP-WUS, the on-duration of the OOK signal can carry a cover sequence and can carry the same information as the existing OOK message itself (and the applicability of the cover to LP-SS was further discussed during the WID discussion). Due to the extremely low rate, the information transmitted for an OOK-based receiver can span multiple time slots, a situation further exacerbated by the use of Manchester encoding, which requires two OFDM symbols of equal duration. This means that when the sequence is encoded only for the on-duration of the full LP-WUS message for cover purposes, the SD-based receiver will also need to remain awake for the entire duration of the LP-WUS message. This unnecessarily increases the power consumption of the SD-based receiver. Furthermore, if the overlay sequence carries the same bit information as the OOK message in each symbol, the SD-based receiver will be severely underutilized. As mentioned above, the information content of ON duration can be increased by using more sequence hypotheses or slicing ON duration in the time domain. However, these will affect performance and may complicate sequence detection, i.e., the greater the number of hypotheses, the higher the LR complexity.

[0066] So, one question is: how can one apply high-order modulation to sequence-based transmissions so that a simple SD-based detector can detect the message?

[0067] The example here at least solves this problem. Now let's outline it. One example proposed in this article is using The symbol s i Modulation superposition sequence, that is, in the mapping Next, the original information bit b i Mapped to where {b i} contains the information bits for the LP-WUS payload. Therefore, each transmitted duration will carry The superposition is a sequence applied during the ON duration to spread the energy over the entire BW (bandwidth), making the signal robust to fading. The constellation is multiplied on top of the sequence. The transmitted duration can be defined as the ON duration of OOK modulation, where the existing OOK symbols provide b according to the MC code. i = {0, 1} as information. The OOK symbol duration can be defined as the CP-OFDM symbol duration without MC coding / M (e.g., (T symb / M)), and CP-OFDM symbol duration with MC coding / (2*M) (e.g., (T symb The constellation C can be considered from the family of phase modulation schemes, such as M-PSK (M-ary Phase Shift Keying).

[0068] In the LP-WUS range, the benefit of using phase modulation (based on the constellation) is that it does not affect the amplitude of the transmission that the ED receiver relies on. Furthermore, in the LP-WUS / SS range, as an additional benefit, the SD receiver uses fewer symbols to decode the full payload compared to an envelope detector that relies on the OOK message. Note that when This benefit is achieved when

[0069] Go to Figure 3 , which is a flow chart executed by an access node for forming an LP-WUS payload for a sequence-based detector using OOK modulation and coding. The access node may be a gNB in ​​a cellular network. However, these techniques can be used wherever an OOK-type signal is available and different receivers are available. Therefore, the techniques herein are not limited to cellular but can be applied to other wireless systems. As described below, other possibilities exist (for cellular), such as a CU (central unit) / DU (distributed unit) combination. In block 310, the access node modulates the superposition sequence with symbols from a constellation to map (e.g., original) information bits to symbols, thereby mapping information bits to symbols. The information bits are at least a portion of the wake-up signal payload (e.g., for a low-power wake-up radio). In block 315, the access node superimposes the modulated superposition sequence on the coding used for on-off keying to form the WUS payload. In block 320, the access node transmits the payload with the wake-up signal to a user device (e.g., including a low-power wake-up radio). In block 325, based on the contents of the payload, the access node communicates with the UE (if the wake-up signal indicates that the UE should wake up, e.g., ON signal 140-2 in FIG. 1) or does not communicate with the UE (if the wake-up signal indicates that the UE should not wake up, e.g., ON signal 140-1 in FIG. 1).

[0070] refer to Figure 4, which is a flow chart performed by a user equipment for decoding and using an LP-WUS payload formed using modulation and coding using OOK. In block 410, a UE (e.g., including a low power wake-up radio 150) receives (e.g., via a wake-up receiver at the UE) a wake-up signal payload having a modulation overlay sequence superimposed on a code for on-off keying. The modulation overlay sequence is formed by a overlay sequence modulated using symbols from a constellation to map information bits to symbols, where the information bits are at least a portion of the wake-up signal payload. In block 420, the UE (e.g., the wake-up receiver at the UE) decodes the symbols to determine the information bits. In block 425, the UE (e.g., the wake-up receiver at the UE) performs a determination by the UE (e.g., the wake-up receiver) based on the information bits (e.g., waking up or not waking up the primary radio, monitoring or not monitoring for paging). In other words, the UE fails to wake up the primary radio and returns to sleep / continues to sleep, wakes up the primary radio to perform various actions, including monitoring for paging, or wakes up the primary radio but does not monitor for paging. In one example, based on the information bits, the UE may monitor for paging signals from the access node. In block 430, the UE 10 may further communicate with the access node or not communicate with the access node based on at least one result (e.g., whether the primary radio is awake, whether the monitoring paging indicates that the UE is paged).

[0071] Now that an overview has been provided, more details are provided. First, constellation-based information on OOK cover sequences is described.

[0072] In all the schemes discussed above for carrying sequence information within the OOK ON duration, the SD receiver extracts the complete LP-WUS payload from the OOK sequence by using fewer ON symbols, either by trading off LR complexity with multiple parallel correlators or by trading off sequence correlation gain with shorter sequences. Therefore, existing techniques for using sequences to send more information bits have serious drawbacks. Instead, the processing gain of a single sequence superimposed on the ON duration can be exploited by using modulation with symbols from a constellation set, where the size of the constellation determines the number of bits carried by the ON duration.

[0073] set up The ON duration of the transmitted symbol or OOK bit sequence in the LP-WUS context is N. s Embedding sequence of . Let s i It comes from the constellation The symbol, its mapping The number of different symbols determines the modulation order of the constellation. In this document, the discussion is limited to M-PSK constellations, as these constellations only contain phase variations without any amplitude variations. Therefore, only low-energy ED LR is not affected by the modulation superposition sequence. For LP-WUS, the original information bits carried by the OOK sequence with or without Manchester coding are obtained by The bits are grouped to determine the modulation symbol for each ON duration, and the corresponding constellation symbol s is selected i .

[0074] Let {b0, b1, ..., b L} is an L-length sequence of information bits carried by the (OOK) symbol. The corresponding modulation symbols {s0, s1, ..., s M} is a set of modulation symbols. Since an M-ary phase modulation scheme is used, each symbol can contain one bit (e.g., BPSK), two bits (e.g., QPSK), three bits (e.g., 8PSK), etc. The ON duration of the superimposed sequence of symbols modulated on symbols {0, ..., m} is as follows:

[0075] and

[0076] Since the constellation considered in this paper is M-PSK, the product of all previous constellation symbols produces valid constellation points in the same constellation space, that is, the constellation is a closed set. In addition, as described below, this structure for ON duration symbol modulation provides benefits when performing decoding. Now, the ON duration sequence transmitted at symbol m is given by {z}×x m If Manchester coding is used, the constellation symbol is used at each LP-WUS symbol instant.

[0077] Figure 5A The figure shows a modulation superposition sequence with a repetition factor of 2 for a non-pilot transmission. Note that a repetition factor of 2 may not be used here or in other scenarios, but using a repetition factor provides the benefit of receiving two sets of identical data. Figure 5A An LP-WUS payload 500 is shown, which contains a modulated superposition sequence that has been encoded using MC coding. This example assumes that Figure 2 Manchester encoding scheme (eg, ON duration followed by OFF duration = bit "0"; OFF duration followed by ON duration = bit "1"). A repetition factor of 2 indicates that the sequence in the first portion 510-1 is identical to the sequence in the second portion 510-2.

[0078] Figure 5B A modulation superposition sequence with a repetition factor of 2 for pilot-assisted transmission is shown. Figure 5BLP-WUS payload 500 is shown, which contains a modulated superposition sequence that has been encoded using MC coding. This payload 500-2 has pilot symbols 520 in the first ON duration, while payload 500-1 does not have pilot symbols. Although pilot symbols 520 are only shown in the first ON duration, pilot symbols 520 can also be implemented in the fifth ON duration.

[0079] In these figures, the information bits conveyed via MC coding for an OOK-based ED receiver are as follows: 01 (bit 550-1); 10 (bit 550-2); 00 (bit 550-3); and 01 (bit 550-4). That is, the MC coding has bits 540 that are 0110 (in portion 510-1) and then 0001 (in portion 510-2). Using Figure 2 The Manchester encoding is such that the ON duration followed by the OFF duration is a bit "0", and the OFF duration followed by the ON duration is a bit "1".

[0080] In this example, the on-off keying encoding can encode a group of bits, and the symbols used to modulate the superimposed sequence encode the same group of bits. Consider using QPSK (i.e., ) The same bit 550 is encoded in symbol x 540: symbol x0 540-1 is used to encode the same bit as MC-coded bit 550-1 and is used in ON duration 530-1; symbol x1 540-2 is used to encode the same bit as MC-coded bit 550-2 and is used in ON duration 530-2; symbol x2 540-3 is used to encode the same bit as MC-coded bit 550-3 and is used in ON duration 530-3; symbol x3 540-3 is used to encode the same bit as MC-coded bit 550-3 and is used in ON duration 530-4. For QPSK, the four ON durations of symbol 540 provide the same information as in all MC-coded bits 550. This example also uses a repetition factor of 2, which means that ON duration 530-5 contains symbol x0 540-1, ON duration 530-6 contains symbol x1 540-2, ON duration 530-7 contains symbol x2 540-3, and ON duration 530-8 contains symbol x3 540-4. Note that having the same information bits encoded by both the MC code and the symbol is an example, and the symbol can contain different bits than those encoded in the MC code. In addition, depending on the constellation used, the symbol can contain more information than the bits encoded by the MC code, and as an example, this additional information can be used for other purposes or ignored.

[0081] Depending on the constellation and payload size, constellation-based coded signaling spans fewer OOK symbols than underlying OOK-based transmission, yet they can carry the same information. Instead of leaving the remaining OOK ON duration empty, the same information can be repeated, and this repeated information can be used for coverage improvement by SD receivers. Therefore, using superimposed sequences can be used for symbol modulation to improve coverage.

[0082] Consider using 8-psk as the modulation symbol, that is This means that the first three symbols 540-1, 540-2 and 540-3 may contain the same bits as bits 550 in the MC encoding (with one extra bit available in symbol 540-3). The fourth symbol 540-4 may be "blank", contain other information, or begin repeating the set of bits 550 again.

[0083] exist Figure 5B In the example, the first ON duration includes a pilot symbol, which may be, for example, a preamble with a known constellation point, such as z0( Figure 5B Not shown in the figure). The underlying OOK carries the same information regarding the pilot symbols. For example, if QPSK is used, the two bits encoded in the first OOK ON duration can be obtained by the two ON durations of the underlying OOK. Therefore, by using the OOK scheme, the SD already knows the bits used for the first constellation, which can then be used as a mapping for the QPSK constellation. Therefore, the pilot symbol (which is x0) is known. In more detail, in one option, the pilot symbol can be z0, which can be explicitly present in the first ON duration. Alternatively, if there is no pilot symbol, the x0 symbol is the same as the preceding symbol embedded in the underlying OOK signal. The symbols in the duration are the same because the information carried by OOK and the embedded constellation is the same.

[0084] After transmitting the above OOK sequence together with the superimposed sequence carrying the modulation symbols, the SD receiver can perform correlation (using or more specifically ), and identifies the constellation used for transmission. Reference i corresponds to a time instant, for example, at each time instant i, the constellation s i is transmitted via a spreading sequence. To analyze this, m Considered as the received signal with channel fading h, it is given as y m =h×{z j}×s m At each OOK ON duration, receiver-side processing is performed at the LR to extract an estimate of the transmitted symbol, as Where T sis the ON duration moment, ΔF is the assumed frequency offset at LR, n is some initial starting point in time samples, is the convolution. In more detail, h is unknown, but when r m and When h×h is determined, due to the channel coherence, * ≈|h| 2 will occur, resulting in a scaling factor. As described below with respect to decoding, an SD receiver can use only the first three ON durations to determine information for decoding all information sent via the OOK bits, and use a superposition sequence for symbol modulation to improve coverage.

[0085] In another design, the transmission may be performed by using only the current symbol as the transmit symbol, ie, x m =s m In this case, LR can use the previous The first symbol is identified by using the underlying OOK symbols (depending on the MC coding) and the first symbol is used as a pilot symbol (also called a reference signal or demodulation reference signal) to determine the channel h, thereby equalizing the remaining symbols.

[0086] Alternatively, multiple sequences can be sent during the ON duration, as in code division multiple access, with each code sequence corresponding to a segment in the bit field. TDM (time division multiplexing) can also be used, but processing gain may be compromised. CDM is preferred to increase the data rate while reducing the constellation carried on each sequence. Figure 6 The diagram shows code division multiple access technology. Figure 6 Two sequences carrying more bits in the ON duration are illustrated. Figure 6 The LP-WUS payload 500-3 is shown, which contains a modulated superposition sequence that has been encoded using MC coding. Two sequences are allocated to each ON duration, where p i Set the first sequence, q i Set the second sequence. So {x0, y0, x1, y1, x2, y2, x3, y3} will be the modulation symbols, each and Each ON duration carries 4 bits. As mentioned before, an SD receiver can use only the first three ON durations to decode all the information sent via the OOK bits, and use a superposition sequence for symbol modulation to improve coverage. In this example, QPSK is used to modulate the symbols, i.e. z0, z1 are known pilot symbols 620-1, 620-2, respectively, used to determine the phase offset. This example also uses a repetition factor of 2, which means that the sequence in part 1 610-1 is the same as the sequence in part 2 610-2, but a repetition factor of 2 is not required. In addition, xi and y i Different modulation orders can be used, e.g. and And one or both of the pilot symbols 620-1 and 620-2 may not be used. The choice of whether to use the pilot symbol is optional. If it is decided to use the pilot symbol, the pilot symbol may be used only once, that is, in Figure 5B Optionally, the entire information set, including the pilot symbols, may be repeated again, such as Figure 6 shown.

[0087] Following are the observations about using two sequences to carry more bits.

[0088] 1) If Figure 6 As shown, use N osq Covering sequence to convey log2 N osq digits. However, as the number of bits per sequence increases, the complexity of the scheme also increases. In addition, the complexity of finding the set of possible sequences is higher. However, note that now for the SD-based detector, the detector can find this information using only the first three MC symbols (in part 1 610-1) because the information in the first three symbols of the second half (part 2 610-2) is just repeated.

[0089] 2) Instead of selecting N osq A fixed superposition sequence can be used to map a set of bits to a modulation symbol using a well-known constellation (such as QPSK, 8PSK, etc.), and then multiply the modulation symbol by a fixed superposition sequence. Here, the SD-based detector can also use only the first three MC symbols in the first part 610-1 to extract all information, because the first three MC symbols in the second part 610-2 only contain repetitions of the first three symbols. The following are some benefits of this approach:

[0090] a) Sequence design is simpler because a fixed sequence is used.

[0091] b) This is easily scaled by changing the constellation (i.e., by choosing a BPSK constellation), one bit is encoded; QPSK can encode two bits; 8PSK can encode three bits; the scaling can be changed based on factors such as the signal conditions at the receiver.

[0092] The biggest advantage of this approach is that frequency offsets present at the receiver due to suboptimal receiver components can be easily compensated by changing the mapping algorithm.

[0093] An example UE implementation is now described.First consider a pilot-free transmission.

[0094] In this case, if Figure 5AAs shown, no pilot sequence is sent to determine the channel between the LR and the gNB. Despite the absence of pilot symbols, the LR with SD can determine the transmitted sequence constellation as follows.

[0095] 1) The first ON duration is received by the SD-based LR, which uses it as a reference after performing correlation with {z}, i.e. using (at least in part) Correlation is performed, which gives Where n is some initial starting point in time samples. ΔF represents the frequency offset experienced by the LR, as the LR may not have an accurate clock to perform effective decoding. The variable T s In other words, {z i} corresponds to a vector, i.e. a sequence. In the correlation (i.e., ) after which one can pick (eg, select) k = argmax i {|r i |} The index with the maximum value can then be picked and the sample r(k) can be used to determine the phase based on the sample r(k) for further processing. In the case of no pilot transmission, two underlying OOK signals may be needed to calculate the constant phase. If we have a pilot symbol z0, only the first OOK ON duration to estimate the constant phase. In addition, assuming that x0 consists of M bits, 2 M ON duration to estimate the value of x0, and 2 M The ones digit is used to estimate the constant phase.

[0096] 2) During the second ON duration, the LR then uses the previously estimated symbols to decode the information during the second OFF duration, i.e. This is due to the effect of frequency offset, i.e. This occurs due to the residual frequency offset present at the receiver. In addition, assuming a unit energy constellation, LR can be decoded Furthermore, as mentioned above, h is unknown, but when r m and (In this example, and ) is determined, due to the channel coherence, h×h * ≈|h| 2 will occur, thus obtaining the scaling factor. As mentioned before, The ON duration symbol modulation structure has advantages when performing decoding. In particular, a benefit is provided because in this example x1 = s0 × s1 results in Can be executed And eliminate one variable used for decoding, which would not happen if x1=s1.

[0097] 3) Further, it can be determined Note that the frequency offset becomes a constant phase due to the differential detection between subsequent symbols.

[0098] 4) When the modulation symbols are in sequence, the correlation gain significantly improves the post-processing SNR, thereby improving the detection capability. After two received symbols, the time-domain received symbol can be used as a pilot for detecting the previous two received symbols.

[0099] 5) Then, after detecting the first two received symbols Afterwards, the received symbols can be decoded as follows, assuming that {x0, x1} is obtained by OOK superposition sequence, since the correlation point itself is known, that is, Can be used as pilot symbols.

[0100] 6) Given x1 and The constant phase component can be determined, namely Other received symbols can then be estimated by compensating this phase according to the position of ON / OFF via Manchester encoding

[0101] Now we introduce pilot-assisted transmission. Here, it is assumed that there is a pilot with known symbols before the actual data transmission. This can be a preamble with known constellation points, i.e., pilot symbols, which can then provide a constant phase error. In this case, there is no need to use the underlying OOK sequence as Figure 5B The pilot shown and described above, because the constant phase error is known. That is, and It will be easier to determine.

[0102] Go to Figure 7 , which shows a block diagram of one possible non-limiting example of a cellular network 1 connected to a user equipment (UE) 10. Figure 7 A number of network elements are shown in the cellular network of FIG: a base station 70 ; and a core network 90 .

[0103] exist Figure 7In the figure, a user equipment (UE) 10 is in wireless communication with a base station 70 of a cellular network 1 via a radio link 11. The UE 10 is a wireless communication device, such as a mobile device, configured to access a cellular network. The UE 10 is shown as having one or more antennas 28. The oval 2 indicates that there can be multiple UEs 10 in wireless communication with the base station 70 via the radio link. The UE 10 includes one or more processors 13, one or more memories 15, and other circuitry 16. The other circuitry 16 includes one or more receivers (Rx) 17 and one or more transmitters (Tx) 18. A program 12 is used to cause the UE 10 to perform the operations described herein. For the UE 10, the other circuitry 16 may include circuitry for user interface elements such as a display (not shown). The program 12 can be implemented via instructions stored in the memory 15 and executed by the processor(s) 13, or by hardware implemented as part of the processor(s) or other hardware elements, or both.

[0104] Base station 70, a network element of cellular network 1, provides UE 10 with access to cellular network 1 and data network 91 via core network 90 (e.g., via the User Plane Function (UPF) of core network 90). Thus, base station 70 can be considered an access node that provides UE(s) 10 with access to cellular network 1. Base station 70 is shown as having one or more antennas 58. Base station 70 may be referred to as a RAN node 70, although many people also refer to it as a gNB (gNode B, base station for NR, new radio). However, many other examples of RAN nodes include eNB (evolved Node B) or TRP (transmission reception point). Base station 70 includes one or more processors 73, one or more memories 75, and other circuitry 76. Other circuitry 76 includes one or more receivers (Rx) 77 and one or more transmitters (Tx) 78. Programming 72 is used to cause base station 70 to perform the operations described herein. The program 72 may be implemented via instructions stored in the memory / memory 75 and executed by the processor(s) 73 , or by hardware implemented as part of the processor(s) or other hardware elements, or both.

[0105] Note that base station 70 may instead be implemented via other wireless technologies, such as Wi-Fi (a wireless network protocol used by devices to communicate without a direct cable connection). In the case of Wi-Fi, link 11 may be characterized as a wireless link, base station 70 may be any access node that allows a UE to connect to the network, and UE 10 may be characterized as a wireless device. For example, for Wi-Fi technology, base station 70 as an access node may be referred to as an access point, and UE 10 may be referred to as a station STA. Network 1 is often referred to as a wireless local area network (or wide area network).

[0106] Two or more base stations 70 communicate using, for example, link(s) 79. Link(s) 79 may be wired or wireless, or both, and may implement, for example, an Xn interface for 5G (fifth generation), an X2 interface for LTE (long term evolution), or other suitable interfaces for other standards.

[0107] Cellular network 1 may include a core network 90 as one or more second network elements. The core network may include core network functions and provide connectivity to a data network 91, such as a telephone network and / or a data communications network (e.g., the Internet), via one or more links 81. Core network 90 includes one or more processors 93, one or more memories 95, and other circuitry 96. Other circuitry 96 includes one or more receivers (Rx) 97 and one or more transmitters (Tx) 98. Programs 92 are used to cause core network 90 to perform the operations described herein. Programs 92 may be implemented via instructions stored in one or more memories 95 and executed by processor(s) 93, or via hardware implemented as part of the processor(s) or other hardware elements, or both.

[0108] The core network 90 may be a 5G core network (5GC). The core network 90 may implement or include multiple network functions (NFs) 99, and the program 92 may include one or more NFs 99. The 5G core network may use hardware such as memory, processors, and a virtualization layer. It may be a single standalone computing system, a distributed computing system, or a cloud computing system. NFs 99, which are network elements of the core network, may be containers or virtual machines running on the hardware of the computing system(s) that make up the core network 90.

[0109] The core network functions of 5G may include access and mobility management functions provided by network functions 99 (such as access and mobility management functions (AMF)), and session management functions provided by network functions (such as session management functions (SMF)). The core network functions for access and mobility management in LTE (Long Term Evolution) networks may be provided by MME (Mobility Management Entity) and / or SGW (Serving Gateway) functions, which route data to the data network. Many other functions are also possible, such as Figure 7 As shown in the example in: AMF; SMF; MME; SGW; GMLC (Gateway Mobile Location Center); LMF (Location Management Function); UDM (Unified Data Management) / UDR (Unified Data Repository); NRF (Network Repository Function); and / or E-SMLC (Evolved Serving Mobile Location Center). These are merely exemplary core network functions that may be provided by the core network 90, and it is noted that both 5G and LTE core network functions may be provided by the core network 90. ​​The base station 70 is coupled to the core network 90 via a backhaul link 31. The base station 70 and the core network 90 may include an NG (Next Generation) interface for 5G, or an S1 interface for LTE, or other suitable interfaces for other radio access technologies, for communicating via the backhaul link 31.

[0110] In the data network 91, there is a computer-readable medium 94. The computer-readable medium 94 contains instructions that, when downloaded and installed into the memory 15, 75, or 95 of the corresponding UE 10, base station 70, and / or core network element(s) 90 and executed by the processor(s) 13, 73, or 93, cause the corresponding device to perform the corresponding actions described herein. The computer-readable medium 94 can be implemented in other forms, such as via an optical disc or a memory stick.

[0111] Programs 12, 72, and 92 include instructions stored by corresponding one or more memories 15, 75, or 95 (as part of the corresponding programs 12, 72, and 92). These instructions, when executed by corresponding one or more processors 13, 73, or 93, cause the corresponding device 10, 70, or 90 to perform the operations described herein. Computer-readable memory 15, 75, or 95 is a circuit system and 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, flash memory, firmware, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Computer-readable memory 15, 75, and 95 can be a component for performing storage functions. Processors 13, 73, and 93 are circuit systems and can be of any type suitable for the local technical environment. For example, these processors may include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture, and may also include dedicated circuits such as a field programmable gate array (FPGA), an application-specific circuit (ASIC), a signal processing device and other devices, or a combination of these devices, as non-limiting examples. Processors 13, 73, and 93 may be components for causing their respective devices to perform functions such as those described herein. In particular, for any device having components for performing the functions described herein, the components may include at least one processor and at least one memory storing instructions that, when executed by at least one processor, cause the above-described execution of the device.

[0112] Receivers 17, 77 and 97 and transmitters 18, 78 and 98 may implement a wired or wireless interface. Receivers and transmitters may be grouped together as a transceiver.

[0113] Cellular network 1 can implement network virtualization, which is a process of combining hardware and software network resources and network functions into a software-based management entity (virtual network). Network virtualization involves platform virtualization (which is often combined with resource virtualization). Network virtualization falls into two categories: external, which combines many networks or network parts into virtual units; and internal, which provides network-like functionality to software containers on a single system. Note that the virtualized entities (such as network function 99) generated by network virtualization are still implemented to some extent using hardware such as processors 73 and / or 93 and memory 75 and / or 95, and such virtualized entities also produce technical effects.

[0114] In general, various embodiments of the user equipment 10 may include, but are not limited to, cellular phones (such as smartphones, mobile phones, cell phones, voice over Internet protocol (VoIP) phones, and / or wireless local loop phones), tablet computers, portable computers, vehicles or onboard devices for, for example, wireless V2X (vehicle-to-everything) communication, image capture devices (such as digital cameras), gaming devices, music storage and playback devices, Internet appliances (including IoT devices), IoT devices with sensors and / or actuators for, for example, automation applications, and portable units or terminals incorporating such functions, laptop embedded devices (LEEs), laptop devices (LMEs), universal serial bus (USB) dongles, smart devices, wireless customer premises equipment (CPE), IoT devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automation process chain environments), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. In other words, the UE 10 may be any terminal device capable of wireless communication. By way of example and not limitation, a UE may also be referred to as a communication device, terminal equipment (MT), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT).

[0115] Here are other examples.

[0116] Example 1. A method comprising: receiving, by a user device, a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed by modulating the superposition sequence using symbols from a constellation to map information bits to the symbols, wherein the information bits are at least a portion of the wake-up signal payload; determining, by the user device, a constant phase error corresponding to an ON duration of the on-off keying and separating received symbols in phase; determining, by the user device, individual received symbols corresponding to individual ON durations of the on-off keying using at least the constant phase error; determining, by the user device, the symbols used to modulate the superposition sequence based on the individual received symbols; determining, by the user device, the information bits corresponding to the determined symbols; and determining at least one result based on the information bits.

[0117] Example 2. A method according to Example 1, wherein: determining the constant phase error includes: performing correlation using the superimposed sequence from the first ON duration of the on-off keying to determine a received sequence having multiple indices corresponding to respective samples; selecting an index having a maximum value from the received sequence from the multiple indices; using the samples corresponding to the index to determine the phase; using at least the phase to determine a first received symbol from the first ON duration; decoding information within the second ON duration of the on-off keying to determine the constant phase error; determining the respective received symbols by the user device using at least the constant phase error includes: determining the respective received symbols using at least the constant phase error for a third ON duration and subsequent ON durations.

[0118] Example 3. The method of Example 2, wherein the first received symbol is x0 having M bits, requiring 2 M ON duration to estimate the value of x0, and another 2 M bits to estimate the constant phase.

[0119] Example 4. The method of any one of Examples 2 or 3, wherein the decoding of information in the second ON duration is based on h×h * ≈|h| 2 , using the channel h in the equation for the first received symbol and the second received symbol within the second ON duration, a scaling factor is determined, and the scaling factor is used in the decoded information.

[0120] Example 5. The method of Example 1, wherein: the first ON duration of the on-off keying includes a pilot symbol; and determining the constant phase error includes determining the constant phase error based on the pilot symbol.

[0121] Example 6. The method of any one of Examples 1 to 5, wherein the symbol from the constellation comprises a first symbol, wherein the wake-up signal payload is received within an ON duration of the on-off keying, wherein the second symbol of the superposition sequence is modulated on symbols {0, ..., m} as follows: x0=s0, x1=s0×s1, ..., where x0, x1, ..., and x m is the second symbol, and s0, s1, ..., and s m is the first symbol, and the ON duration sequence transmitted at symbol m is given by {z}×x m is given by , where {z} is the superposition sequence.

[0122] Example 7. A method according to any one of Examples 1 to 6, wherein each modulated superposition sequence is sent with a repetition factor of 2.

[0123] Example 8. A method according to any one of Examples 1 to 7, wherein the encoding for on-off keying includes Manchester encoding, wherein a first value of a bit is encoded using an ON duration, the ON duration includes a portion of the modulation superposition sequence, the ON duration is preceded by an empty OFF duration, and a second value of the bit is encoded using the OFF duration that is empty, the OFF duration is preceded by an ON duration that includes another portion of the modulation superposition sequence.

[0124] Example 9. The method of any one of Examples 1 to 8, wherein the constellation is from a family of phase modulation schemes.

[0125] Example 10. The method of any one of Examples 1 to 9, wherein the encoding for on-off keying encodes a group of bits, and the symbols used to modulate the superimposed sequence encode the same group of bits.

[0126] Example 11. An apparatus comprising components for: receiving a wake-up signal payload having a modulated overlay sequence superimposed on a code for on-off keying, wherein the modulated overlay sequence is formed by modulating the overlay sequence with symbols from a constellation to map information bits to the symbols, wherein the information bits are at least a portion of the wake-up signal payload; determining a constant phase error corresponding to an ON duration of the on-off keying and separating received symbols in phase; determining individual received symbols corresponding to individual ON durations of the on-off keying using at least the constant phase error; determining the symbols used to modulate the overlay sequence based on the individual received symbols; determining the information bits corresponding to the determined symbols; and determining at least one result based on the information bits.

[0127] Example 12. An apparatus according to Example 11, wherein: determining the constant phase error includes: performing correlation using the superimposed sequence from the first ON duration of the on-off keying to determine a received sequence having multiple indices corresponding to respective samples; selecting an index having a maximum value from the received sequence from the multiple indices; determining a phase using samples corresponding to the index; using at least the phase to determine a first received symbol from the first ON duration; decoding information within the second ON duration of the on-off keying to determine the constant phase error; determining the respective received symbols by the user device using at least the constant phase error includes: determining the respective received symbols using at least the constant phase error for a third ON duration and subsequent ON durations.

[0128] Example 13. The apparatus of Example 12, wherein the first received symbol is x0 having M bits, requiring 2 M ON duration to estimate the value of x0, and another 2 M bits to estimate the constant phase.

[0129] Example 14. The apparatus of any of Examples 12 or 13, wherein the information decoded in the second ON duration is based on h×h * ≈|h| 2 , using the channel h in the equation for the first received symbol and the second received symbol within the second ON duration, a scaling factor is determined, and the scaling factor is used in the decoded information.

[0130] Example 15. The apparatus of Example 11, wherein: the first ON duration of the on-off keying comprises a pilot symbol; and determining the constant phase error comprises determining the constant phase error based on the pilot symbol.

[0131] Example 16. An apparatus according to any one of Examples 11 to 15, wherein the symbol from the constellation includes a first symbol, wherein the wake-up signal payload is received within the ON duration of the on-off keying, wherein the second symbol of the superposition sequence is modulated on symbols {0, ..., m} as follows: x0=s0, x1=s0×s1, ..., where x0, x1, ..., and x m is the second symbol, and s0, s1, ..., and s m is the first symbol, and the ON duration sequence transmitted at symbol m is given by {z}×x m is given by , where {z} is the superposition sequence.

[0132] Example 17. An apparatus according to any one of Examples 11 to 16, wherein each modulated superposition sequence is transmitted with a repetition factor of 2.

[0133] Example 18. An apparatus according to any one of Examples 11 to 17, wherein the encoding for on-off keying comprises Manchester encoding, wherein a first value of a bit is encoded using an ON duration, the ON duration comprising a portion of the modulation superposition sequence, the ON duration being preceded by an empty OFF duration, and a second value of the bit is encoded using the OFF duration being empty, the OFF duration being preceded by an ON duration comprising another portion of the modulation superposition sequence.

[0134] Example 19. An apparatus according to any one of Examples 11 to 18, wherein the constellation is from a family of phase modulation schemes.

[0135] Example 20. An apparatus according to any one of Examples 11 to 19, wherein the code used for on-off keying encodes a group of bits, and the symbols used to modulate the superposition sequence encode the same group of bits.

[0136] Example 21. An apparatus according to any of the preceding apparatus examples, wherein the components include: at least one processor; and at least one memory storing instructions that, when executed by at least one processor, cause the execution of the apparatus.

[0137] Example 22. A device comprising: one or more processors; and one or more memories, wherein at least one or more memories store instructions that, when executed by the one or more processors, cause the device to at least perform: receiving, by a user device, a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed by modulating the superposition sequence using symbols from a constellation to map information bits to the symbols, wherein the information bits are at least a portion of the wake-up signal payload; determining, by the user device, a constant phase error corresponding to the ON duration of the on-off keying and separating received symbols in phase; determining, by the user device, individual received symbols corresponding to individual ON durations of the on-off keying using at least the constant phase error; determining, by the user device, the symbols used to modulate the superposition sequence based on the individual received symbols; determining, by the user device, the information bits corresponding to the determined symbols; and determining at least one result based on the information bits.

[0138] Example 23. An apparatus according to Example 22, wherein: determining the constant phase error includes: performing correlation using the superimposed sequence from the first ON duration of the on-off keying to determine a received sequence having multiple indices corresponding to respective samples; selecting an index having a maximum value from the received sequence from the multiple indices; determining a phase using samples corresponding to the index; using at least the phase to determine a first received symbol from the first ON duration; decoding information within the second ON duration of the on-off keying to determine the constant phase error; determining the respective received symbols by the user device using at least the constant phase error includes: determining the respective received symbols using at least the constant phase error for a third ON duration and subsequent ON durations.

[0139] Example 24. The apparatus of Example 23, wherein the first received symbol is x0 having M bits, requiring 2 M ON duration to estimate the value of x0, and another 2 M bits to estimate the constant phase.

[0140] Example 25. The apparatus of any of Examples 23 or 24, wherein the decoding of information within the second ON duration is based on h×h * ≈|h| 2 , using the channel h in the equation for the first received symbol and the second received symbol within the second ON duration, a scaling factor is determined, and the scaling factor is used in the decoded information.

[0141] Example 26. The apparatus of Example 22, wherein: the first ON duration of the on-off keying comprises a pilot symbol; and determining the constant phase error comprises determining the constant phase error based on the pilot symbol.

[0142] Example 27. An apparatus according to any of Examples 22 to 26, wherein the symbol from the constellation includes a first symbol, wherein the wake-up signal payload is received within the ON duration of the on-off keying, wherein the second symbol of the superposition sequence is modulated on symbols {0, ..., m} as follows: x0=s0, x1=s0×s1, ..., where x0, x1, ..., and x m is the second symbol, and s0, s1, ..., and s m is the first symbol, and the ON duration sequence transmitted at symbol m is given by {z}×x m is given by , where {z} is the superposition sequence.

[0143] Example 28. An apparatus according to any one of Examples 22 to 27, wherein each modulated superposition sequence is transmitted with a repetition factor of 2.

[0144] Example 29. An apparatus according to any one of Examples 22 to 28, wherein the encoding for on-off keying comprises Manchester encoding, wherein a first value of a bit is encoded using an ON duration, the ON duration comprising a portion of the modulation superposition sequence, the ON duration being preceded by an empty OFF duration, and a second value of the bit is encoded using the OFF duration being empty, the OFF duration being preceded by an ON duration comprising another portion of the modulation superposition sequence.

[0145] Example 30. An apparatus according to any one of Examples 22 to 29, wherein the constellation is from a family of phase modulation schemes.

[0146] Example 31. An apparatus according to any one of Examples 22 to 30, wherein the code used for on-off keying encodes a group of bits, and the symbols used to modulate the superposition sequence encode the same group of bits.

[0147] Example 32. A computer program comprising instructions for performing the method according to any one of Examples 1 to 10 when the computer program is run on a device.

[0148] Example 33. The computer program of Example 32, wherein the computer program is a computer program product comprising a computer-readable medium carrying instructions embodied therein for use with the apparatus.

[0149] Example 34. The computer program of example 32, wherein the computer program is directly loadable into an internal memory of the apparatus.

[0150] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0151] (a) pure hardware circuit implementation (such as implementation in analog and / or digital circuitry only) and

[0152] (b) a combination of hardware circuitry and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuitry and software / firmware, and (ii) any portion of hardware processor(s) (including digital signal processor(s)) with software, software and memory(s) that work together to cause a device such as a mobile phone or server to perform various functions, and

[0153] (c) Hardware circuit(s) and / or processor(s), such as microprocessor(s) or portion(s) of microprocessor(s), that require software (e.g., firmware) for operation, but where not required for operation, the software may not be present.

[0154] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another 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. For example, if applicable to a particular claim element, the term circuitry also includes 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.

[0155] The embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., application specific integrated circuits), or a combination of software and hardware. In example embodiments, the software (e.g., application logic, instruction sets) is maintained on any of a variety of conventional computer-readable media. In the context of this document, a "computer-readable medium" can be any medium or component that can contain, store, communicate, propagate, or transport instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, where an example of a computer is a computer. Figure 7 Described and depicted in . Computer-readable media may include computer-readable storage media (e.g., memories 15, 75, and 95 or other devices), which may be any medium or component that can contain, store, and / or transmit instructions for use by or in conjunction with an instruction execution system, apparatus, or device (such as a computer). Computer-readable storage media do not include propagating signals and, therefore, may be considered non-transitory. The term "non-transitory" as used herein is a limitation on the medium itself (i.e., tangible, not a signal), not on the persistence of data storage (e.g., random access memory RAM versus read-only memory ROM).

[0156] If desired, the different functions discussed herein may be performed in different orders and / or simultaneously with each other. In addition, if desired, one or more of the above functions may be optional or combinable.

[0157] Although various aspects of the invention are set out in the independent claims, further aspects of the invention comprise other combinations of features from the described embodiments and / or dependent claims with features from the independent claims, not just the combinations explicitly set out in the claims.

[0158] It should also be noted herein that although the above describes example embodiments of the present invention, these descriptions should not be viewed in a limiting sense. On the contrary, several variations and modifications are possible without departing from the scope of the present invention as defined in the appended claims.

Claims

1. A method for communication, comprising: receiving a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed of a superposition sequence modulated with symbols from a constellation to map information bits to the symbols, wherein the information bits are at least a portion of the wake-up signal payload; determining a constant phase error corresponding to the ON duration of the on-off keying and separating received symbols in phase; determining respective received symbols corresponding to respective ON-durations of the on-off keying using at least the constant phase error; determining the symbols for modulating the superimposed sequence based on the respective received symbols; determining the information bit corresponding to the determined symbol; as well as At least one result is determined based on the information bits.

2. An apparatus for communication, comprising means for: receiving a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed of a superposition sequence modulated with symbols from a constellation to map information bits to the symbols, wherein the information bits are at least a portion of the wake-up signal payload; determining a constant phase error corresponding to the ON duration of the on-off keying and separating received symbols in phase; determining respective received symbols corresponding to respective ON-durations of the on-off keying using at least the constant phase error; determining the symbols for modulating the superimposed sequence based on the respective received symbols; determining the information bit corresponding to the determined symbol; as well as At least one result is determined based on the information bits.

3. The device according to claim 2, wherein: Determining the constant phase error includes: performing a correlation using the superimposed sequence of first ON durations from the on-off keying to determine a received sequence having a plurality of indices corresponding to respective samples; selecting, from the plurality of indices, an index having a maximum value from the received sequence; determining a phase using samples corresponding to the index; determining a first received symbol from the first ON duration using at least the phase; decoding information during a second ON duration of the on-off keying to determine the constant phase error; Using at least the constant phase error to determine the respective received symbols includes using at least the constant phase error to determine the respective received symbols for a third ON-duration and subsequent ON-durations.

4. The apparatus of claim 3, wherein the first received symbol is x0 having M bits, requiring 2 M ON duration to estimate the value of x0, and another 2 M The ones digit is used to estimate the constant phase.

5. The apparatus according to claim 3 or 4, wherein the information decoded in the second ON duration is based on h×h * ≈|h| 2 , using the channel h in the equation for the first received symbol and the second received symbol within the second ON duration, a scaling factor is determined, and the scaling factor is used in the decoded information.

6. The device according to claim 2, wherein: The first ON duration of the on-off keying includes a pilot symbol; and Determining the constant phase error includes determining the constant phase error based on the pilot symbols.

7. The apparatus of any one of claims 2 to 6, wherein the symbols from the constellation comprise a first symbol, wherein the wake-up signal payload is received within an ON duration of the on-off keying, wherein a second symbol modulating the superimposed sequence on symbols {0, ..., m} is given by: where x0, x1, ..., and x m is the second symbol, and s0, s1, ..., and s m is the first symbol, and the ON duration sequence transmitted at symbol m is given by {z}×x m is given by , where {z} is the superposition sequence.

8. The apparatus according to any one of claims 2 to 7, wherein each modulated superposition sequence is transmitted with a repetition factor of 2.

9. An apparatus according to any one of claims 2 to 8, wherein the encoding for on-off keying comprises Manchester encoding, wherein a first value of a bit is encoded using an ON duration, the ON duration comprising a portion of the modulation superposition sequence, the ON duration being preceded by an empty OFF duration, and a second value of the bit is encoded using the empty OFF duration, the OFF duration being preceded by an ON duration comprising another portion of the modulation superposition sequence.

10. The apparatus according to any one of claims 2 to 9, wherein the constellation is from a family of phase modulation schemes.

11. The apparatus according to any one of claims 2 to 10, wherein the code used for on-off keying encodes a group of bits, and the symbols used to modulate the superimposed sequence encode the same group of bits.

12. The device of any preceding device claim, wherein the component comprises: at least one processor; as well as At least one memory stores instructions that, when executed by at least one processor, cause execution of the apparatus.

13. The apparatus according to any one of claims 2 to 11, wherein the apparatus is a user equipment.

14. An apparatus for communication, comprising: one or more processors; as well as One or more memories, wherein at least one or more memories store instructions that, when executed by the one or more processors, cause the apparatus to at least perform: receiving a wake-up signal payload having a modulated superposition sequence superimposed on a code for on-off keying, wherein the modulated superposition sequence is formed of a superposition sequence modulated with symbols from a constellation to map information bits to the symbols, wherein the information bits are at least a portion of the wake-up signal payload; determining a constant phase error corresponding to the ON duration of the on-off keying and separating received symbols in phase; determining respective received symbols corresponding to respective ON-durations of the on-off keying using at least the constant phase error; determining the symbols for modulating the superimposed sequence based on the respective received symbols; determining the information bit corresponding to the determined symbol; as well as At least one result is determined based on the information bits.

15. A computer program comprising instructions for executing the method according to claim 1 when the computer program is run on a device.

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