Method and apparatus for transmitting resource efficient signaling to LP-wur

Abstract

Aspects of the disclosure generally relate to wireless communications. In some aspects, a method implemented in a wireless device is provided that includes receiving a low-power wake-up signal (low-power wake-up signal, LP-WUS) configuration from a network side device, the LP-WUS configuration indicating a set of frequency resources allocated for an LP-WUS transmission. The method further includes determining, according to the LP-WUS configuration, one or more subsets of the set of frequency resources to be allocated to one or more bits associated with the LP-WUS transmission; and determining a first reference signal and a second reference signal according to the LP-WUS configuration. The method further comprises: receiving one or more signals from the network side device on the frequency resource set; determining one or more signal levels from the one or more signals; the one or more bits are determined according to the one or more signal levels, the first reference signal, and the second reference signal.

Description

[0001] Priority claims and cross-references

[0002] This patent application claims priority to U.S. Provisional Application No. 63 / 485,403, filed on February 16, 2023, entitled “Methods for Efficient Support of In-Band Selectivity and High Data for LP-WURS,” and U.S. Provisional Application No. 63 / 485,417, filed on February 16, 2023, entitled “Methods and Apparatus for Resource Efficient Signaling to LP-WUR,” both of which are hereby incorporated by reference as if reproduced in their entirety. Technical Field

[0003] The present invention generally relates to methods and apparatus for wireless communications and, in particular embodiments, to methods and apparatus for resource-efficient signaling to a low power wake-up radio (LP-WUR). Background Art

[0004] In 3GPP meetings, on-off keying (OOK) and frequency shift keying (FSK) are being discussed as potential modulation schemes, and several architectures are being considered. The target data rate of 100 kbps may require higher-order modulation than OOK and 2-FSK.

[0005] The study items for NR's low-power wake-up signal (LP-WUS) and low-power wake-up receiver (LP-WUR) were approved at the 3GPP RAN#94e meeting and revised in RAN#97e. The study covers low-power receiver architectures, signal and protocol designs, and evaluation methods, targeting metrics such as energy savings, latency, coverage availability, coexistence with non-low-power WUR UEs, and network resource overhead. RAN1#110bis-e agreed on several receiver architectures supporting OOK modulation schemes, including architectures with RF envelope detection, heterodyne architectures with intermediate frequency (IF) envelope detection, and homodyne / zero IF architectures with baseband (BB) envelope detection. These architectures can also be applied to other modulation schemes, such as frequency shift keying (FSK). The suitability of other modulation schemes for LP-WUR is still under discussion at the 3GPP RAN1 meeting. Furthermore, target data rates of around 100 kbps are being discussed, which may require support for higher modulation orders than those supported by OOK and 2-FSK. In this paper, a LP-WUS design is presented that enables resource-efficient support of higher-order modulations for LP-WUR. Summary of the Invention

[0006] According to one embodiment, a method implemented in a wireless device is provided, comprising: receiving a low-power wake-up signal (LP-WUS) configuration from a network-side device, the LP-WUS configuration indicating a set of frequency resources allocated for LP-WUS transmission. The method further comprises: determining, based on the LP-WUS configuration, one or more subsets of the set of frequency resources to be allocated to one or more bits associated with the LP-WUS transmission; and determining, based on the LP-WUS configuration, a first reference signal and a second reference signal. The method further comprises: receiving one or more signals from the network-side device on the set of frequency resources. The method further comprises: determining one or more signal levels based on the one or more signals; and determining the one or more bits based on the one or more signal levels, the first reference signal, and the second reference signal.

[0007] In one embodiment, determining the one or more bits based on the one or more signal levels, the first reference signal, and the second reference signal includes determining a relative difference relative to the first reference signal and the second reference signal. In one embodiment, the first reference signal includes a first intensity representing a bit "0," and the second reference signal includes a second intensity representing a bit "1," and determining the one or more bits based on the one or more signal levels, the first reference signal, and the second reference signal includes decoding a first bit of the one or more bits as "1" when a difference between a first signal level of the one or more signal levels and the first reference signal is less than a difference between the first signal level of the one or more signal levels and the second reference signal. In one embodiment, the first reference signal includes a first intensity representing a bit "0," and the second reference signal includes a second intensity representing a bit "1," and determining the one or more bits based on the one or more signal levels, the first reference signal, and the second reference signal includes decoding the first bit of the one or more bits as "0" when a difference between a first signal level of the one or more signal levels and the first reference signal is greater than a difference between the first signal level of the one or more signal levels and the second reference signal. In one embodiment, the method further comprises: passing the one or more signals through an envelope detector before determining one or more signal levels based on the one or more signals. In one embodiment, each of the one or more signals comprises on-offkeying (OOK) modulation. In one embodiment, the LP-WUS configuration is received in a higher layer signal. In one embodiment, the LP-WUS configuration further indicates at least one of: a number of bits multiplexed in an orthogonal frequency-division multiplexing (OFDM) symbol; a number of LP-WUSs multiplexed in the frequency domain; a first subset of frequency resources allocated for a zero reference signal; or a second subset of frequency resources allocated for a consistent reference signal. In one embodiment, the first reference signal comprises a first strength, and the first strength comprises an estimated noise level strength. In one embodiment, the second reference signal comprises a second strength, and the second strength comprises an estimated interference power and channel fading level strength. In one embodiment, determining the first reference signal and the second reference signal based on the LP-WUS configuration further comprises: receiving at least one of the first reference signal or the second reference signal from the network device.

[0008] According to one embodiment, a method implemented in a wireless transmit / receive unit (WTRU) is provided, the method comprising: receiving a low-power wake-up signal (LP-WUS) configuration, the LP-WUS configuration indicating a set of frequency resources allocated for LP-WUS transmission. The method further comprises: determining one or more subsets of the set of frequency resources to be allocated to one or more bits associated with the LP-WUS transmission. The method further comprises: determining a first strength based on a first signal received on a first subset of frequency resources. The method further comprises: determining a second strength based on a second signal received on a second subset of frequency resources. The method further comprises: determining one or more signal levels based on the one or more signals received on the one or more subsets of the set of frequency resources. The method further comprises: detecting one or more bits based on the first strength, the second strength, and the one or more signal levels.

[0009] In one embodiment, the LP-WUS configuration is received in a higher layer signal. In one embodiment, the LP-WUS configuration further indicates at least one of the following: the number of bits multiplexed in an orthogonal frequency-division multiplexing (OFDM) symbol; the number of LP-WUSs multiplexed in the frequency domain; a first subset of frequency resources allocated for a zero reference signal; or a second subset of frequency resources allocated for a consistent reference signal. In one embodiment, the first strength is an estimated noise level strength. In one embodiment, the second strength is an estimated interference power and channel fading level strength.

[0010] According to one embodiment, a method for wireless communication implemented in a wireless transmit / receive unit (WTRU) is provided, the method comprising: receiving a low-power wake-up signal (LP-WUS) configuration, the LP-WUS configuration indicating a first type of signaling, a second type of signaling, and a reference signal configuration, wherein the WTRU includes a first power state and a second power state. The method further comprises: determining a received signal strength based on the reference signal configuration. The method further comprises: operating a receiver in the first power state and monitoring a signal based on the first type of signaling based on a first condition on the received signal strength. The method further comprises: operating the receiver in the second power state and monitoring the signal based on the second type of signaling based on a second condition on the received signal strength.

[0011] In one embodiment, the reference signal configuration further indicates a configured signal strength magnitude. In one embodiment, the first condition is that the received signal strength is greater than the configured signal strength magnitude. In one embodiment, the second condition is that the received signal strength is less than the configured signal strength magnitude. In one embodiment, the LP-WUS configuration further indicates a post-envelope detection (ED) center frequency and a post-ED bandwidth. In one embodiment, the first power state is lower than the second power state. In one embodiment, monitoring the signal according to the first type of signaling is based on the post-ED center frequency and the post-ED bandwidth. In one embodiment, the LP-WUS configuration further indicates one or more pre-ED center frequencies and one or more pre-ED bandwidths. In one embodiment, monitoring the signal according to the second type of signaling is based on the one or more pre-ED center frequencies and the one or more pre-ED bandwidths. In one embodiment, a radio frequency (RF) ED LP-WUR is used in the first power state. In one embodiment, an intermediate frequency (IF) / baseband (BB) ED LP-WUR is used in the second power state. In one embodiment, the LP-WUS configuration indicates support for at least one of a post-ED signaling design, a pre-ED signal, a post-ED signal, an LP-WUS transmission data rate, or an LP-WUS coding scheme and coding rate. In one embodiment, the first condition is support for the post-ED signaling design. In one embodiment, the second condition is non-support for the post-ED signaling design.

[0012] According to one embodiment, a method is provided, comprising: a base station sending a low-power wake-up signal (LP-WUS), wherein the LP-WUS generates a signal of at least a specific intermediate frequency / center frequency (IF) after / after envelope detection (ED) for demodulation and detection of a wake-up signal (WUS) message in a receiver.

[0013] In one embodiment, the LP-WUS signal transmitted by the base station includes at least two sets of contiguous frequency resources separated by the IF. In one embodiment, the LP-WUS signal transmitted by the base station includes at least one contiguous frequency resource, and background traffic signals at each frequency are separated from the contiguous frequency resource by the specific IF.

[0014] According to one embodiment, a method is provided, comprising: a base station sending a low-power wake-up signal (LP-WUS), wherein the LP-WUS generates a signal of at least a specific intermediate frequency / center frequency (IF) after / after envelope detection (ED) for demodulation and detection of a wake-up signal (WUS) message in a receiver.

[0015] In one embodiment, the LP-WUS signal transmitted by the base station includes at least two sets of contiguous frequency resources separated by the IF. In one embodiment, the LP-WUS signal transmitted by the base station includes at least one contiguous frequency resource, and background traffic signals at each frequency are separated from the contiguous frequency resource by the specific IF.

[0016] According to one embodiment, a method implemented in a base station is provided, the method comprising: determining a low-power wake-up signal (LP-WUS) configuration for a wireless device, wherein the LP-WUS configuration comprises one or more subsets of a set of frequency resources to be allocated to one or more bits associated with the LP-WUS. The method further comprises: transmitting the LP-WUS configuration to the wireless device, the LP-WUS configuration indicating a set of frequency resources allocated for LP-WUS transmission. The method further comprises: transmitting one or more signals to the wireless device on the set of frequency resources.

[0017] In one embodiment, the one or more signals are based on on-offkeying (OOK) modulation coding. In one embodiment, the LP-WUS configuration is received in a higher layer signal. In one embodiment, the LP-WUS configuration further indicates at least one of the following: the number of bits multiplexed in an orthogonal frequency-division multiplexing (OFDM) symbol, or the number of LP-WUS multiplexed in the frequency domain. In one embodiment, the LP-WUS configuration further indicates a first subset of frequency resources allocated for a zero reference signal. In one embodiment, the LP-WUS configuration further indicates a second subset of frequency resources allocated for a consistent reference signal. In one embodiment, the method further includes: determining the one or more signal levels based on one or more bits, a first reference signal, and a second reference signal, wherein bits having a first bit value are encoded based on the first reference signal and bits having a second bit value are encoded based on the second reference signal. In one embodiment, the first reference signal includes a first strength indicating a bit "0," and the second reference signal includes a second strength indicating a bit "1," and the method further includes: determining the one or more signals based on the one or more bits, the first reference signal, and the second reference signal includes: encoding a first signal of the one or more signals to have a strength equal to that of the first reference signal when a first bit of the one or more bits is "1," or encoding the first signal of the one or more signals to have a strength equal to that of the second reference signal when the first bit of the one or more bits is "0." In one embodiment, the method further includes: transmitting at least one of the first reference signal or the second reference signal to the wireless device.

[0018] According to one embodiment, an apparatus is provided, comprising at least one processor; and a non-transitory memory storing programming instructions, wherein when the programming instructions are executed by the at least one processor, the apparatus causes the system to perform any one of the methods described above.

[0019] According to one embodiment, a non-transitory computer-readable storage medium is provided, comprising instructions, which, when executed by a processor, cause the processor to perform any of the methods described above.

[0020] According to one embodiment, a wireless transmit / receive unit (WTRU) is provided, comprising at least one processor and a non-transitory computer-readable storage medium storing a program, wherein the program comprises instructions that, when executed by the at least one processor, cause the WTRU to perform any of the methods disclosed above.

[0021] According to one embodiment, a base station is provided, comprising at least one processor and a non-transitory computer-readable storage medium storing a program, wherein the program comprises instructions that, when executed by the at least one processor, cause the base station to perform any one of the methods disclosed above. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] For a more complete understanding of the present invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1 A wireless system for low-power wake-up signaling provided by an embodiment is shown;

[0024] Figure 2 An exemplary protocol plow / timeline based on DRX configuration provided by an embodiment is shown;

[0025] Figure 3 The embodiment provides a method based on eDRX (T eDRX >1024 frames) configuration;

[0026] Figure 4 An exemplary protocol flow / timeline based on LP-WUS configuration with UE addressing provided by an embodiment is shown;

[0027] Figure 5 An exemplary protocol flow / timeline based on LP-WUS configuration with UE group addressing provided by an embodiment is shown;

[0028] Figure 6 An overview of a low-power receiver architecture provided by an embodiment is shown;

[0029] Figure 7 A basic block diagram of an RF envelope detection receiver architecture provided by an embodiment is shown;

[0030] Figure 8 An example of a synchronous switching / double sampling receiver architecture provided by an embodiment is shown;

[0031] Figure 9 An example of a 2-subcarrier receiving envelope detection receiver architecture provided by an embodiment is shown;

[0032] Figure 10 A basic block diagram of an IF envelope detection receiver architecture provided by an embodiment is shown;

[0033] Figure 11 A basic block diagram of a BB envelope detection receiver architecture provided by an embodiment is shown;

[0034] Figure 12 An example of a subsampling receiver architecture provided by an embodiment is shown;

[0035] Figure 13 An example of an uncertain IF receiver architecture provided by an embodiment is shown;

[0036] FIG141 shows a representation of a dual-uncertain IF receiver architecture provided by an embodiment;

[0037] Figure 15 is an exemplary 1-bit FSK receiver architecture using a parallel OOK receiver provided by an embodiment;

[0038] Figure 16 An exemplary FSK receiver architecture utilizing an analog domain FM-to-AM detector is shown.

[0039] Figure 17 An exemplary FSK receiver architecture utilizing an analog domain FM-to-AM detector is shown.

[0040] Figure 18 An exemplary 1-bit FSK (2-FSK) receiver using an IF envelope detection based receiver architecture provided by an embodiment is shown;

[0041] Figure 19 An exemplary frequency response of a single OFDM symbol under LP-WUS dual spectrum allocation is shown;

[0042] Figure 20 An exemplary frequency response of a single OFDM symbol under the LP-WUS dynamic design with single spectrum allocation is shown;

[0043] Figure 21 An exemplary OFDM-based transmitter architecture is shown, enabling dynamic design of LP-WUS with single spectrum allocation.

[0044] Figure 22 is a graphical representation of the envelope detection operation on the frequency spectrum of a signal;

[0045] FIG23( a ) shows a reference radio architecture for conventional OOK;

[0046] FIG23( b ) shows the RF spectrum of the input signal to the envelope detector for a conventional OOK design;

[0047] FIG23( c ) shows the reference radio architecture for collaboratively generated IF envelope OOK;

[0048] FIG23( d ) shows a diagram of the RF spectrum of the input signal to the envelope detector for a co-generated IF envelope OOK design and the process for generating the IF envelope signal;

[0049] Figure 24 is a graphic illustration of the feasibility / advantages of a dynamic LP-WUS design for an IF envelope detection receiver architecture;

[0050] Figure 25 is an illustration of parallel bitstream support / generation for an IF envelope detection receiver architecture using dynamic LP-WUS design;

[0051] Figure 26 is an exemplary frequency response of a single OFDM symbol under the parallel LP-WUS design with dual spectrum allocation;

[0052] Figure 27 An exemplary RF envelope detection receiver architecture supporting dual spectrum allocation and dynamic LP-WUS design schemes;

[0053] Figure 28 An exemplary IF envelope detection receiver architecture supporting dual spectrum allocation and dynamic LP-WUS design schemes;

[0054] Figure 29 is an exemplary RF envelope detection receiver architecture supporting dual spectrum allocation with parallel bit streams and a dynamic LP-WUS design scheme;

[0055] Figure 30 is an exemplary flow chart illustrating a process for a UE to dynamically switch between RF and IF / BB envelope detection architectures based on network support;

[0056] Figure 31 is an exemplary flow chart illustrating an embodiment process of a UE dynamically switching between RF and IF / BB envelope detection architectures based on network support and RSRP measurements;

[0057] Figure 32 is an exemplary flow chart illustrating an embodiment process of a UE dynamically switching between RF and IF / BB envelope detection architectures based on network support and interference signal measurements;

[0058] Figure 33 An exemplary 2-bit FSK receiver architecture utilizing a parallel OOK receiver is shown;

[0059] Figure 34An exemplary 4-bit FSK, i.e., 16-FSK receiver structure is shown;

[0060] Figure 35 An exemplary algorithm (e.g., decision criteria) that may be used by an M-Dec (e.g., multi-threshold comparator) unit is shown;

[0061] Figure 36 An exemplary receiver structure 3600 is shown as a parallel 4-bit receiver that can receive N bits using only N+1 frequency resources based on a differential modulation / coding scheme;

[0062] Figure 37 An exemplary algorithm (e.g., decision criteria) that may be used by an M-Dec (e.g., multi-threshold comparator) unit is shown;

[0063] Figure 38 An embodiment process implemented at a base station for processing an LP-WUS of a single LP-WUR using two fixed frequency resources as references is shown;

[0064] Figure 39 An embodiment process implemented in a base station for processing an LP-WUS of a single LP-WUR using differential modulation is shown;

[0065] Figure 40 An embodiment process implemented in a UE for handling LP-WUS using two fixed frequency resources as reference is shown;

[0066] Figure 41 An embodiment process implemented in a UE for handling LP-WUS using one frequency resource as a reference is shown;

[0067] Figure 42 An exemplary communication system is shown;

[0068] Figure 43 An exemplary communication system is shown;

[0069] Figure 44A and Figure 44B An exemplary device is shown in which the methods and instructions according to the present invention may be implemented;

[0070] Figure 45 is a block diagram of a computing system that can be used to implement the devices and methods disclosed herein.

[0071] Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated.The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale. DETAILED DESCRIPTION

[0072] The following describes in detail the making and using of embodiments of the present invention. However, it should be understood that the concepts disclosed herein can be embodied in a variety of specific contexts, and that the specific embodiments discussed herein are illustrative only and are not intended to limit the scope of the claims. Furthermore, it should be understood that various changes, substitutions, and modifications may be made herein without departing from the spirit and scope of the present invention as defined by the appended claims.

[0073] Various embodiments of communication systems will now be presented with reference to various devices and methods. These devices and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and design constraints imposed on the overall system.

[0074] Disclosed herein are methods, systems, and apparatus for sending resource-efficient signaling to LP-WUR. Also disclosed herein are methods, systems, and apparatus for efficiently supporting in-band selectivity and high data for LP-WUR.

[0075] In various embodiments, a method implemented in a wireless device is provided, comprising: receiving a low-power wake-up signal (LP-WUS) configuration from a network-side device, the LP-WUS configuration indicating a set of frequency resources allocated for LP-WUS transmission. The method further comprises: determining, based on the LP-WUS configuration, one or more subsets of the set of frequency resources to be allocated to one or more bits associated with the LP-WUS transmission; and determining, based on the LP-WUS configuration, a first reference signal and a second reference signal. The method further comprises: receiving one or more signals from the network-side device on the set of frequency resources. The method further comprises: determining one or more signal levels based on the one or more signals; and determining the one or more bits based on the one or more signal levels, the first reference signal, and the second reference signal.

[0076] Some embodiments of the present invention provide that determining the one or more bits based on the one or more signal levels, the first reference signal, and the second reference signal includes determining a relative difference relative to the first reference signal and the second reference signal. Some embodiments of the present invention provide that the first reference signal includes a first strength or threshold indicating a bit "0," and the second reference signal includes a second strength or threshold indicating a bit "1," and that determining the one or more bits based on the one or more signal levels, the first reference signal, and the second reference signal includes decoding a first bit of the one or more bits as "1" when a difference between a first signal level of the one or more signal levels and the first reference signal is less than a difference between the first signal level of the one or more signal levels and the second reference signal. Some embodiments of the present invention provide that the first reference signal includes a first strength or threshold indicating a bit "0," and the second reference signal includes a second strength or threshold indicating a bit "1," and that determining the one or more bits based on the one or more signal levels, the first reference signal, and the second reference signal includes decoding the first bit of the one or more bits as "0" when a difference between a first signal level of the one or more signal levels and the first reference signal is greater than a difference between the first signal level of the one or more signal levels and the second reference signal. Optionally, in some embodiments, when the difference between the first signal level of the one or more signal levels and the first reference signal is equal to the difference between the first signal level of the one or more signal levels and the second reference signal, the first bit of the one or more bits is decoded as "0". Optionally, in some embodiments, when the difference between the first signal level of the one or more signal levels and the first reference signal is equal to the difference between the first signal level of the one or more signal levels and the second reference signal, the first bit of the one or more bits is decoded as "1". Some embodiments of the present invention provide that the method further includes: before determining one or more signal levels based on the one or more signals, passing the one or more signals through an envelope detector. In one embodiment, each of the one or more signals includes on-offkeying (OOK) modulation. Some embodiments of the present invention provide that the LP-WUS configuration is received in a high-layer signal.Some embodiments of the present invention provide that the LP-WUS configuration further indicates at least one of the following: the number of bits multiplexed in an orthogonal frequency-division multiplexing (OFDM) symbol; the number of LP-WUS multiplexed in the frequency domain; a first subset of frequency resources allocated for a zero reference signal; or a second subset of frequency resources allocated for a consistent reference signal. Some embodiments of the present invention provide that the first reference signal includes a first strength or threshold, wherein the first strength or threshold includes an estimated noise level strength or threshold. Some embodiments of the present invention provide that the second reference signal includes a second strength or threshold, wherein the second strength or threshold includes an estimated interference power and channel fading level strength or threshold. In one embodiment, determining the first reference signal and the second reference signal based on the LP-WUS configuration further includes: receiving at least one of the first reference signal or the second reference signal from the network device.

[0077] In various embodiments, a method implemented in a wireless transmit / receive unit (WTRU) is provided, the method comprising: receiving a low-power wake-up signal (LP-WUS) configuration indicating a set of frequency resources allocated for LP-WUS transmission. The method further comprises: determining one or more subsets of the set of frequency resources to be allocated to one or more bits associated with the LP-WUS transmission. The method further comprises: determining a first strength or threshold based on a first signal received on a first subset of frequency resources. The method further comprises: determining a second strength or threshold based on a second signal received on a second subset of frequency resources. The method further comprises: determining one or more signal levels based on the one or more signals received on the one or more subsets of the set of frequency resources. The method further comprises: detecting the one or more bits based on the first strength or threshold, the second strength or threshold, and the one or more signal levels.

[0078] In one embodiment, the LP-WUS configuration is received in a higher layer signal. In one embodiment, the LP-WUS configuration further indicates at least one of the following: the number of bits multiplexed in an orthogonal frequency-division multiplexing (OFDM) symbol; the number of LP-WUS multiplexed in the frequency domain; a first subset of frequency resources allocated for a zero reference signal; or a second subset of frequency resources allocated for a consistent reference signal. In one embodiment, the first strength or threshold is an estimated noise level strength or threshold. In one embodiment, the second strength or threshold is an estimated interference power and channel fading level strength or threshold.

[0079] In various embodiments, a method for wireless communication implemented in a wireless transmit / receive unit (WTRU) is provided, the method comprising: receiving a low-power wake-up signal (LP-WUS) configuration, the LP-WUS configuration indicating a first type of signaling, a second type of signaling, and a reference signal configuration, wherein the WTRU comprises a first power state and a second power state. The method further comprises: determining a received signal strength based on the reference signal configuration. The method further comprises: operating a receiver in the first power state and monitoring for signals based on the first type of signaling based on a first condition on the received signal strength. The method further comprises: operating the receiver in the second power state and monitoring for signals based on the second type of signaling based on a second condition on the received signal strength.

[0080] Some embodiments of the present invention provide that the reference signal configuration further indicates a configured signal strength level or threshold. In one embodiment, the first condition is that the received signal strength is greater than the configured signal strength level or threshold. In one embodiment, the second condition is that the received signal strength is less than the configured signal strength level or threshold. Some embodiments of the present invention provide that the LP-WUS configuration further indicates a post-envelope detection (ED) center frequency and a post-ED bandwidth. Some embodiments of the present invention provide that the first power state is lower than the second power state. Some embodiments of the present invention provide that the monitoring of the signal according to the first type of signaling is based on the post-ED center frequency and the post-ED bandwidth. Some embodiments of the present invention provide that the LP-WUS configuration further indicates one or more pre-ED center frequencies and one or more pre-ED bandwidths. Some embodiments of the present invention provide that the monitoring of the signal according to the second type of signaling is based on the one or more pre-ED center frequencies and the one or more pre-ED bandwidths. Some embodiments of the present invention provide that a radio frequency (RF) ED LP-WUR is used in the first power state. Some embodiments of the present invention provide that an intermediate frequency (IF) / baseband (BB) ED LP-WUR is used in the second power state. Some embodiments of the present invention provide that the LP-WUS configuration indicates support for at least one of a post-ED signaling design, a pre-ED signal, a post-ED signal, an LP-WUS transmission data rate, or an LP-WUS coding scheme and coding rate. Some embodiments of the present invention provide that the first condition is support for the post-ED signaling design. In one embodiment, the second condition is non-support for the post-ED signaling design.

[0081] In various embodiments, a method is provided, comprising: a base station sending a low-power wake-up signal (LP-WUS), wherein the LP-WUS generates a signal of at least a specific intermediate frequency (IF) after / after envelope detection (ED) for demodulation and detection of a wake-up signal (WUS) message in a receiver.

[0082] Some embodiments of the present invention provide that the LP-WUS signal transmitted by the base station includes at least two sets of contiguous frequency resources separated by the IF. In one embodiment, the LP-WUS signal transmitted by the base station includes at least one contiguous frequency resource, and background traffic signals at each frequency are separated from the contiguous frequency resource by the specific IF.

[0083] According to one embodiment, a method is provided, comprising: a base station sending a low-power wake-up signal (LP-WUS), wherein the LP-WUS generates a signal of at least a specific intermediate frequency / center frequency (IF) after / after envelope detection (ED) for demodulation and detection of a wake-up signal (WUS) message in a receiver.

[0084] In one embodiment, the LP-WUS signal transmitted by the base station includes at least two sets of contiguous frequency resources separated by the IF. In one embodiment, the LP-WUS signal transmitted by the base station includes at least one contiguous frequency resource, and background traffic signals at each frequency are separated from the contiguous frequency resource by the specific IF.

[0085] According to one embodiment, a method implemented in a base station is provided, the method comprising: determining a low-power wake-up signal (LP-WUS) configuration for a wireless device, wherein the LP-WUS configuration comprises one or more subsets of a set of frequency resources to be allocated to one or more bits associated with the LP-WUS. The method further comprises: transmitting the LP-WUS configuration to the wireless device, the LP-WUS configuration indicating a set of frequency resources allocated for LP-WUS transmission. The method further comprises: transmitting one or more signals to the wireless device on the set of frequency resources.

[0086] In one embodiment, the one or more signals are based on on-offkeying (OOK) modulation coding. In one embodiment, the LP-WUS configuration is received in a higher layer signal. In one embodiment, the LP-WUS configuration further indicates at least one of the following: the number of bits multiplexed in an orthogonal frequency-division multiplexing (OFDM) symbol, or the number of LP-WUS multiplexed in the frequency domain. In one embodiment, the LP-WUS configuration further indicates a first subset of frequency resources allocated for a zero reference signal. In one embodiment, the LP-WUS configuration further indicates a second subset of frequency resources allocated for a consistent reference signal. In one embodiment, the method further includes: determining the one or more signal levels based on one or more bits, a first reference signal, and a second reference signal, wherein bits having a first bit value are encoded based on the first reference signal and bits having a second bit value are encoded based on the second reference signal. In one embodiment, the first reference signal includes a first strength indicating a bit "0," and the second reference signal includes a second strength indicating a bit "1," and the method further includes: determining the one or more signals based on the one or more bits, the first reference signal, and the second reference signal includes: encoding a first signal of the one or more signals to have a strength equal to that of the first reference signal when a first bit of the one or more bits is "1," or encoding the first signal of the one or more signals to have a strength equal to that of the second reference signal when the first bit of the one or more bits is "0." In one embodiment, the method further includes: transmitting at least one of the first reference signal or the second reference signal to the wireless device.

[0087] In various embodiments, a wireless transmit / receive unit (WTRU) is provided, comprising at least one processor and a non-transitory computer-readable storage medium storing a program, wherein the program includes instructions that, when executed by the at least one processor, cause the WTRU to perform any of the methods disclosed above.

[0088] In various embodiments, a base station is provided, comprising at least one processor and a non-transitory computer-readable storage medium storing a program, the program comprising instructions that, when executed by the at least one processor, cause the base station to perform any of the methods disclosed above.

[0089] In various embodiments, an apparatus is provided, comprising at least one processor; and a non-transitory memory storing programming instructions, which, when executed by the at least one processor, cause the system to perform any of the methods described above.

[0090] In various embodiments, a non-transitory computer-readable storage medium is provided, comprising instructions that, when executed by a processor, cause the processor to perform any of the methods described above.

[0091] Figure 1 A wireless system 100 for low-power wake-up signaling provided by an embodiment is shown. System 100 is an example of a system that can be used to implement the disclosed method. System 100 includes a base station transmitter subsystem 102 and a UE 112. The base station transmitter subsystem 102 includes a conventional communication signal encoding and modulation unit 104, an LP-WUS signal generation and modulation unit 106, a conversion to RF amplification and filtering unit 108, and an antenna 110 for sending and receiving signals. The UE 112 includes a main radio 114, a low-power wake-up radio 116, and an antenna 118 for sending and receiving signals. The low-power wake-up radio 116 is used to support sleep mode operation of the UE 112. This may be particularly useful for Internet of Things (IoT) devices. When the UE 112 is in sleep mode, the main radio 114 is turned off to reduce power consumption. The low-power wake-up radio 116 monitors the air signal of the LP-WUS from the base station transmitter subsystem 102. Once the low power wake-up radio 116 detects the LP-WUS, it sends a control signal to wake up the main radio 114 for communication. The base station transmitter subsystem 102 generates the LP-WUS through the LP-WUS signal generation and modulation unit 106, and then transmits the LP-WUS together with the regular communication signal generated by the regular communication signal encoding and modulation unit 104 to the UE 112 to wake up the UE 112 in the sleep mode so that the UE 112 can communicate with the base station transmitter subsystem 102.

[0092] 3GPP defines duty cycle operation in the form of discontinuous reception (DRX) and extended discontinuous reception (eDRX) to reduce power consumption in the NRRRC_IDLE and RRC_INACTIVE states by reducing the number of paging occasions (PO) monitored by the UE. In the NRRRC_IDLE and RRC_INACTIVE states, power consumption is further reduced by paging early indication (PEI), but is still affected by duty cycle operation. Similar energy-saving techniques are defined for the NRRRC_CONNECTED state in the form of connected mode DRX (C-DRX) and wake-up signal (WUS). Both PEI and WUS can be received by the UE as DCI on the PDCCH.

[0093] Figure 2 FIG2 shows an exemplary protocol plow / timeline 200 based on DRX configuration provided by an embodiment. For a UE using DRX in RRC_IDLE or RRC_INACTIVE state, such as Figure 2 As shown, it monitors one PEI occasion (PEI-O) and / or one PO per DRX cycle based on the PEI configuration, where the PEI-O / PO consists of a group of PDCCH monitoring occasions (MO) and can consist of multiple time slots. After receiving a CN-initiated paging or a RAN-initiated paging, the UE initiates the RRC connection establishment or RRC connection recovery process, respectively. If PEI is configured, the UE will monitor the associated PO during the DRX cycle only when the PEI is detected and the PEI indicates the subgroup corresponding to the UE.

[0094] Figure 3 The embodiment provides a method based on eDRX (T eDRX >1024 frames) configuration. For a UE using eDRX in RRC_IDLE or RRC_INACTIVE state, if the configured eDRX cycle is not longer than 1024 radio frames, the UE monitors one PEI-O and / or one PO per eDRX cycle based on the PEI configuration, such as Figure 2Otherwise, the UE monitors one PEI-O and / or one PO per eDRX cycle based on the configured DRX cycle during the UE-specific periodic paging time window (PTW), where the PTW period is determined by the eDRX cycle and the length is configured by upper layers, as shown in Figure 3 After receiving a CN-initiated or RAN-initiated paging call, the UE initiates an RRC connection establishment or RRC connection recovery procedure, respectively. If PEI is configured, the UE monitors the associated PO during the DRX / eDRX cycle only if the PEI is detected and the PEI indicates the subgroup to which the UE belongs.

[0095] DRX, eDRX, and C-DRX can provide higher energy savings by increasing the duty cycle duration, but at the expense of an increase in the UE's expected latency. PEI and WUS can provide even greater energy savings without compromising latency, but this gain is limited by the power consumption required to decode the DCI on the PDCCH. The new WUS, which can receive at significantly lower power than the existing PEI / WUS design, can achieve a new trade-off between latency and power consumption, but requires a dedicated low-power wake-up radio / receiver (LP-WUR) with a simple architecture, as described below.

[0096] The idea behind using LP-WUR to achieve energy savings is to keep the main radio (MR), which consumes a lot of power in the mW range, in a dormant power state as long as possible, and to have the LP-WUR, which should consume 2 to 3 orders of magnitude less power than the MR, monitor the LP-WUS as a trigger to wake up the MR. There are two options for how the LP-WUR can monitor the LP-WUS, and the following terms are used interchangeably to identify each option:

[0097] Option 1: Continuous and Always-On Monitoring

[0098] Option 2: “Discontinuous,” “Periodic,” and “Duty Cycle” monitoring

[0099] In addition, depending on the content of the LP-WUS and the network configuration, there are three different options for the UE's behavior in response to receiving the LP-WUS. These three UE behavior options can be applied to both LP-WUS monitoring "Option 1" and "Option 2", respectively:

[0100] UE_Behavior (1): LP-WUS carries the UEID and does not require MR to monitor PO.

[0101] UE_Behavior (2): LP-WUS carries UEID and / or UE group ID, and requires MR to monitor the legacy PO / PF.

[0102] UE_Behavior (3): LP-WUS carries UEID and / or UE group ID, and MR is required to monitor the newly defined PO / PF.

[0103] Figure 4 An exemplary protocol flow / timeline 400 based on LP-WUS configuration with UE addressing is shown in FIG. Figure 4 As shown, UE_Behavior (1) may achieve the best experienced latency under the LP-WUS energy saving scheme, especially when using continuous monitoring mode (option 1). This is because the UE can wake up the primary radio to directly initiate the RRC connection establishment or RRC connection recovery procedure upon receiving a CN-initiated page or a RAN-initiated page, respectively, as indicated by the LP-WUS. When considering periodic LP-WUS monitoring, this UE behavior also eliminates the need to align the LP-WUR and MR duty cycles. However, this comes at the expense of a larger LP-WUS payload size and, subsequently, potentially higher resource overhead requirements.

[0104] Figure 5 An exemplary protocol flow / timeline 500 based on LP-WUS configuration with UE group addressing according to an embodiment is shown. Figure 5 As shown, UE_Behavior (2) will result in LP-WUS latency performance that is limited by the conventional DRX cycle, i.e., {0.32, 0.64, 1.28, 2.56} seconds, and will always be inferior to the DRX energy-saving scheme under the same DRX cycle configuration in terms of latency. This is because the UE still has to use the MR to monitor the PO in response to detecting an LP-WUS wakeup. However, energy-saving gains can still be expected compared to DRX, i.e., depending on the UE group size, and due to the possible use of UE group IDs instead of UE unique IDs, there may be a managed LP-WUS resource overhead. Compared to UE_Behavior (1), and based on the UE group size, i.e., when UE_Behavior (2) takes the UE group ID into account, there may be a power consumption penalty given the expected high transition energy of the MR from the "ultra-deep sleep" power state, which may limit any power saving gains. Furthermore, when the LP-WUS carries one or more UE Group IDs, considering "always on" monitoring of the LP-WUS under UE_Behavior(2) may not achieve any latency reduction benefit compared to the DRX energy saving scheme, since the MR still has to monitor the PO according to any traditional DRX cycle. However, the "always on" monitoring mode can alleviate the need for the LP-WUS to periodically synchronize with the transmitting entity.

[0105] UE_Behavior(3) may correspond to the definition of a shorter RRCIDLE / INACTIVE state DRX cycle (i.e. <320ms), which may achieve better LP-WUS latency performance compared to UE_Behavior(2) without any impact on power consumption due to the use of LP-WUS and under managed LP-WUS resource overhead due to the use of UE Group ID.

[0106] Both UE_Behavior (2) and UE_Behavior (3) can also be used in situations where the LP-WUS carries a unique UEID but the MR is still required to monitor the PO. However, for LP-WUS with a very low false alarm rate (FAR), it may not be reasonable to force the MR to monitor the PO after detecting an LP-WUS carrying a unique UEID. This is because the MR's PO monitoring will increase power consumption without providing any additional information to the UE.

[0107] Low-power receiver architecture

[0108] Figure 6 An overview of a low power receiver architecture 600 provided by an embodiment is shown. A dedicated low power receiver LP-WUR is proposed as a supplement to the UE's MR to reduce power consumption associated with the current requirement that the UE periodically wakes up once per DRX cycle to monitor the PDCCH. Figure 6 The two carrier frequency ranges (f c ≤1GHz ​​and 1GHz <f c ≤3GHz), there is a trade-off between receiver power consumption, sensitivity, and supported data rates. Figure 6 shows that it consumes 40μW <P c The receiver architecture can support a sensitivity level of -97dBm at data rates of 10kbps ≤ R < 200kbps using non-coherent OOK modulation with a power of ≤140μW. <P min ≤-70dBm. In the following sections, we will examine some of these receiver architectures. Generally, the low-power receiver architectures examined can be categorized as mixing-first architectures, such as uncertain IF, subsampling, and dual uncertain IF architectures; and envelope detection-first architectures, such as dual sampling and 2-subcarrier receiver architectures. Several low-power receiver architectures suitable for FSK modulation are described below.

[0109] The 3GPP standard specifies the modulation format of the signal. For example, control channels and shared channels are often modulated on resource elements (REs) within the physical resource block using binary phase shift keying (BPSK), quadrature phase shift keying (QPSK) / 4-quadrature amplitude modulation (QAM), 16-QAM, 64-QAM, and possibly 256-QAM. There are also reference signals on the REs, which can have Zadoff-Chu modulation. Before transmission, the REs can be transformed in waveforms using (inverse) fast Fourier transform (FFT) and / or discrete Fourier transform (DFT). With the introduction of wake-up receivers, a second modulation format different from the above can be used to generate the wake-up signal. Examples of the second modulation format may include frequency shift keying (FSK) and on-off keying (OOK).

[0110] The network can provide (send) the configuration of the wake-up signal to the wireless device. The configuration may include parameters such as whether to use OOK or FSK, bandwidth, data rate, symbol rate, etc. When the mobile device supports the use of WUR, WUR then monitors WUS (first modulation format). The mobile device no longer monitors the modulation format used for reference signals, control channels, shared channels (second modulation format). When WUS is detected, the mobile device starts monitoring the modulation format used for reference signals, control channels and shared channels for a configurable duration. For example, it can set a timer. When the timer expires (or after the duration), if the wireless device does not receive any control / shared channels associated with the wireless device, the wireless device can resume monitoring of WUS. The association may include RNTI.

[0111] ASK receiver architecture

[0112] In this section, amplitude shift keying (ASK) (eg, OOK) receiver architectures are discussed in the context of the types identified in the 3GPP RAN1 discussions, namely, RF envelope detection and IF / BB envelope detection architectures.

[0113] RF envelope detection (ED)

[0114] Figure 7FIG1 shows a basic block diagram of a receiver architecture 700 for RF envelope detection provided by an embodiment. The basic block diagram for RF envelope detection is described in RAN1#110bis-e, as shown in FIG1. Figure 7 As shown. An RF envelope detector is used to convert the RF signal directly to baseband, eliminating the need for an LO or phase-locked loop (PLL). Signal digitization for digital baseband processing can be performed using a 1-bit or multi-bit ADC. Optionally, an RF low noise amplifier (LNA) and / or a BB amplifier (AMP) can be considered. For this architecture, a high-Q matching network and / or an RF BPF is considered to suppress adjacent channel interference or interference from legacy NR signals and / or other LP-WUS on adjacent subcarriers.

[0115] Figure 8 An example of a synchronous switching / dual sampling receiver architecture 800 provided by an embodiment is shown. Formerly known as the dual sampling architecture, this is another architecture that attempts to reduce the power consumption overhead associated with FEPLLs by utilizing a low-frequency oscillator that is one to two orders of magnitude lower than the target RF frequency. This architecture also mitigates the effects of 1 / f (flicker) noise by incorporating a clipping / switching stage at the RF, a dual sampling / switching stage at the IF, and utilizing a clock frequency that is higher than the flicker noise corner frequency. Figure 8 An exemplary dual sampling architecture is shown in , where the IFBPF stage may be followed by an amplification stage. Since RF envelope detection is used in this architecture, the receiver selectivity is primarily controlled by the RFFE filter.

[0116] Sometimes, to achieve low power consumption of approximately 51 μW, FE selectivity is compromised, resulting in a –3dB bandwidth of 21 MHz / 59 MHz in the 915 MHz / 2.4 GHz bands, while the receiver architecture achieves –75 dBm / –80 dBm sensitivity in the 915 MHz band using a data rate of 100 kbps / 10 kbps. In some embodiments, the receiver architecture provides a FE –3dB bandwidth of 110 MHz, determined by the LNA and input matching network, and achieves a sensitivity of –86.5 dBm / –61 dBm in the 780 to 950 MHz band using a data rate of 10 kbps, consuming 146 μW / 64 μW (supporting a 100 kbps data rate at a sensitivity degradation of approximately 5 dB). However, using a high-QRF SAW filter can improve receiver selectivity to a –3dB bandwidth of only 13 MHz, at the expense of approximately 2 dB of sensitivity degradation. The power consumption of some receiver architectures can be further reduced by discarding the LNA at the RF, at the expense of further degradation of receiver sensitivity.

[0117] Figure 9FIG. 9 shows an example of a 2-subcarrier receive envelope detection receiver architecture 900 provided by an embodiment. As with the dual sampling architecture, Figure 9 The architecture shown utilizes RF envelope detection and a low-frequency oscillator to reduce power consumption. However, some architectures use a two-subcarrier transmission scheme instead of the switching / clipping technique used in the dual-sampling architecture, which multiplies the received RF signal with a low-frequency square wave. In addition, this architecture treats the dual-sampling / switching stage at the IF (i.e., after envelope detection) as a mixing stage and utilizes a FESAW filter to improve the receiver's interference rejection.

[0118] Specific signal designs considering a two-subcarrier transmission scheme support the use of BPSK-IF as the modulation scheme for receiver architectures based on non-coherent envelope detection. This also improves receiver selectivity for better in-band interference rejection. Therefore, some architectures manage out-of-band interference rejection through SAW filters and in-band interference rejection through signal design and an IFBPF following envelope detection. In the 915MHz band, this achieves a sensitivity of –83dBm / –56dBm using a 10kbps data rate, consuming approximately 121μW / 63.5μW (+10μW for IF clock generation). When accounting for the losses introduced by the SAW filter, this architecture exhibits similar sensitivity to some dual-sampling architectures. However, compared to dual-sampling architectures, it offers significantly better interference rejection performance, as it can tolerate an in-band carrier-to-interference ratio (CIR) of –19dB to –10.5dB at ±1MHz offset from each subcarrier, based on power consumption.

[0119] RAN1#110bis-e describes the basic block diagrams for IF and BB envelope detection, respectively. Figure 10 and Figure 11 shown. Figure 10 FIG. 1 shows a basic block diagram of an IF envelope detection receiver architecture 1000 provided by an embodiment. Figure 11 FIG. 1 shows a basic block diagram of a BB envelope detection receiver architecture 1100 provided by an embodiment. Figure 10), the RF signal is first converted to an IF signal using an LO and an RF mixer, and then the IF signal is converted to a BB signal using an IF envelope detector. In this architecture, low power consumption is achieved by reducing the accuracy and stability requirements of the LO. Signal digitization for digital baseband processing can be performed using a 1-bit or multi-bit ADC. Optionally, an RF low noise amplifier (LNA) and / or IFAMP and / or BBAMP can be considered. For this architecture, high Q matching networks and / or RFBPF and / or IFBPF are considered to suppress adjacent channel interference or interference from legacy NR signals and / or other LP-WUS on adjacent subcarriers. In addition, an image rejection filter or an image rejection mixer is also required. On the other hand, the BB envelope detection architecture ( Figure 11 ) directly converts the RF signal in the BB signal. Consider using a high-Q matching network and / or an RFBPF and / or a BBBPF / LPF to suppress adjacent channel interference or interference from legacy NR signals and / or other LP-WUS on adjacent subcarriers. Furthermore, no image rejection filter is required.

[0120] Similar to the double-sampling architecture, the sub-sampling architecture attempts to reduce the power consumption overhead associated with the FEPLL by utilizing a low-frequency oscillator that is one to two orders of magnitude lower than the target RF frequency. However, rather than the switching / clipping technique used in the double-sampling architecture, which multiplies the received RF signal with a low-frequency square wave, some sub-sampling architectures use a low-frequency clock to subsample the received RF signal and generate the signal at the IF. Furthermore, some receiver architectures utilize an indeterminate IF topology, which utilizes a low-power and low-precision reference clock but improves receiver selectivity by utilizing cycle-based calibration circuitry.

[0121] Figure 12 An example of a subsampling receiver architecture 1200 provided by an embodiment is shown. Figure 12 In the exemplary subsampling architecture shown, receiver selectivity is determined by a SAW filter and two active inductor-based amplifier stages providing approximately 13MHz bandwidth. Figure 12 The architecture shown achieves a sensitivity of –75dBm in the 915MHz band using a 200kbps Manchester-coded data rate with a power consumption of approximately 22.9μW (the calibration circuit consumes an average of 0.3μW per 100ms calibration, which lasts for 1ms).

[0122] Figure 13An example of an uncertain IF receiver architecture 1300 provided by an embodiment is shown. The uncertain IF architecture 1300 is one of the architectures that attempts to reduce or eliminate the power consumption overhead associated with the front-end (FE) phase-locked loop (PLL) and low noise amplifier (LNA). This is achieved by utilizing (1) a low power and low precision unlocked local oscillator (LO), such as a ring oscillator, and (2) an LNA at the IF rather than the RF. The power consumption overhead associated with the LNA can be further eliminated by completely removing the LNA from the architecture, at the expense of receiver sensitivity. Figure 13 An exemplary uncertain IF architecture 1300 is shown, in which receiver selectivity (i.e., blocker cancellation) is achieved by utilizing a passive high-Q front-end filter and additional filtering after the mixer, which is more easily provided at low frequencies. Architecture 1300 provides a –3dB bandwidth of 54MHz through RF filtering, while the IF bandwidth is limited by the uncertainty of the ring oscillator used.

[0123] Therefore, in this architecture, sensitivity is typically limited by the integrated noise introduced by the wide IF bandwidth required to handle LO uncertainties. In an architecture similar to Architecture 1300, a data rate of 10 is achieved in the 2.45 GHz band using 250 kbps Manchester coding (information bits are encoded as transitions from low to high or high to low signal levels). -3 The BER is –88dBm with a power consumption of approximately 50μW.

[0124] Figure 142 shows a representation of a dual uncertain IF receiver architecture 1400 provided by an embodiment. Figure 14 The dual uncertain IF receiver architecture 1400 shown in FIGURE 1 reuses the uncertain IF receiver architecture to reduce power consumption while improving receiver selectivity by combining an unlocked low-Q resonator reference LO (LC-DCO) and distributed multi-stage high-Q N-path passive mixer (N-PPM) filtering technology, wherein the LC-DCO provides higher accuracy than the ring oscillator at the expense of a slightly increased power consumption.

[0125] The dual-uncertain IF architecture selectivity is then provided by two main narrow-bandpass filtering stages, each at one of the two IF frequencies, enabling an in-band carrier-to-interference ratio (CIR) tolerance of –25dB to –22dB at ±3MHz offset. The FE matching network and RF passive mixer provide an effective bandwidth of 20MHz, while the first IF passive mixer provides an effective bandwidth of 1MHz. This architecture achieves a sensitivity of –97dBm / –92dBm in the 2.4GHz band using data rates of 10kbps / 50kbps, consuming approximately 99μW of power.

[0126] Envelope detection in the dual-uncertainty IF architecture exploits the highly linear response of the N-PPM to downconvert the signal from the second IF frequency directly to DC, ensuring bandwidth reduction and eliminating LO uncertainty effects.

[0127] FSK receiver architecture

[0128] Figure 15 FIG. 15 is an exemplary 1-bit FSK receiver architecture 1500 using a parallel OOK receiver provided in an embodiment. Figure 16 An exemplary FSK receiver architecture 1600 utilizing an analog domain FM-to-AM detector is shown, provided in accordance with an embodiment. Figure 17 An exemplary FSK receiver architecture 1700 using an analog domain FM-to-AM detector provided by an embodiment is shown. As part of the LP-WUS study project, a low-power receiver architecture that can support FSK modulation is also being discussed in 3GPP RAN1. So far, two exemplary architectures have been considered, the first example (parallel OOK receiver) reuses the OOK receiver architecture, and the second example uses an FM-to-AM detector. Based on the parallel OOK receiver example, Figure 15 An exemplary architecture of a 1-bit FSK (2-FSK) receiver is shown in FIG, where each envelope detector can be implemented using any OOK receiver architecture. On the other hand, for an FSK receiver based on an FM-to-AM detector, two alternative implementations are possible. In one implementation, the FM-to-AM detector is implemented in the analog domain, such as Figure 16 While the FM-to-AM detector is implemented in the digital domain in the second implementation, Figure 17 .

[0129] for Figure 15In the exemplary architecture shown, a signal transmitted using frequency resource f1 can be used to indicate the transmission of bit 0, while a signal transmitted using frequency resource f2 can be used to indicate the transmission of bit 1. The received FSK signal then enters two bandpass filters centered on f1 and f2, respectively, before entering an envelope detector circuit. The output of the envelope detector is then fed into a comparator to determine whether bit 0 or bit 1 is being transmitted.

[0130] It should be noted that if Figure 15 The FSK receiver shown may be based on an RF envelope detector receiver architecture. Therefore, the two bandpass filters may be RF filters, which may be expensive and / or bulky, making the architecture unattractive for implementation. Alternatively, an IF envelope detection-based receiver architecture may be utilized to avoid the expensive and / or bulky implementation. Figure 18 An exemplary 1-bit FSK (2-FSK) receiver 1800 using an IF envelope detection-based receiver architecture is shown. As described above, to reduce power consumption in an IF envelope detection architecture, a low-precision and low-stability LO, such as a ring oscillator, may be used. Low LO accuracy (e.g., ±200 ppm) may result in a frequency offset of ±400 kHz at a 2 GHz carrier frequency. This frequency offset may require a relatively wide guard band to avoid / mitigate interference, which in turn may increase the frequency resources required for such an architecture.

[0131] Part 4

[0132] One benefit of the various disclosed embodiments is that the number of non-contiguous frequency resources capable of transmitting the same number of bits / symbols on a single OFDM symbol is reduced. The following is a signal (e.g., LP-WUS) design that targets the low-power receiver architecture disclosed herein while reducing the front-end RF filter design and / or guard band requirements.

[0133] Signal Design

[0134] In this section, in-band selectivity-aware LP-WUS designs are introduced, and the feasibility and advantages of these designs for mixer-first receiver architectures (i.e., IF / BB envelope detection architectures) are further discussed below.

[0135] Dual spectrum allocation

[0136] For RF envelope detection architecture, you can consider Figure 19The dual spectrum allocation scheme shown in the figure helps to suppress interference. In this scheme, LP-WUS frequency resources are allocated at both edges of the channel, with unallocated resources, i.e., guard bands, between the LP-WUS resources and the resources allocated to any other signals. This allocation scheme can achieve fixed and in-band selective sensing signal design. Since the RF signal x(t) in the RF envelope detection architecture is detected by the nonlinear operation of the RF envelope detector (e.g., self-mixing x(t)×x * (t)) is directly converted into a baseband signal, so the spectrum of the obtained baseband signal is It is equivalent to the autocorrelation of the spectrum of the RF signal, where (·) * is the conjugate operation, is the Fourier transform operation, is a convolution operation. Then, using a fixed dual spectrum allocation signal design, the LP-WUS can be extracted in the baseband of the WUR as a signal centered at a known / fixed frequency, e.g., B1-B2 (based on the design of the LP-WUS and the guard band at RF), and having a passband bandwidth, e.g., ≈2B2, where B1 is the channel RF bandwidth and B2 is the LP-WUS RF bandwidth.

[0137] Figure 19 An exemplary frequency response 1900 of a single OFDM symbol under LP-WUS dual spectrum allocation is shown.

[0138] Through this frequency resource allocation, the existing NR signal or any interfering signal that falls within the spectrum occupied by the NR signal will not generate a baseband envelope signal at the frequency of the desired signal, and therefore will not interfere with the reception of the desired signal, thereby achieving intra-band selectivity. It should be noted that although the dual spectrum allocation scheme can solve the intra-band selectivity problem, that is, suppressing interference from signals on adjacent subcarriers, it requires sufficient protection band around the frequency resources allocated to LP-WUS. Therefore, the dual spectrum allocation scheme may not be a spectrum-efficient scheme, but it can be applicable to situations where LP-WUS is expected to share channels only with low resource utilization signals / transmissions (such as SSB), thereby achieving a simple and fixed LP-WUS design. In addition, this scheme can be used for both OFDM-OOK and DFT-OOK.

[0139] Collaborative (dynamic) generation of IF envelopes

[0140] In contrast to the dual spectrum allocation scheme with a fixed LP-WUS design, another scheme can consider allocating a single continuous spectrum to the LP-WUS at only one of the channel edges. However, the LP-WUS generated to occupy this spectrum is dynamically designed to take into account the interference signal (i.e., generated due to the envelope detection operation) that occupies the other edge of the channel, such as Figure 20 exemplified. Figure 21 An exemplary OFDM-based transmitter architecture that can be used to generate a cooperatively / dynamically designed LP-WUS is shown.

[0141] Figure 20 An exemplary frequency response 2000 of a single OFDM symbol for a LP-WUS dynamic design with a single spectrum allocation is shown.

[0142] exist Figure 21 In the exemplary transmitter architecture shown, part of the NR signal / channel (i.e., to be multiplexed with the LP-WUS signal) is determined as an interfering signal with LP-WUS In this example, based on the target design of the frequency resources to be occupied by the LP-WUS after envelope detection of the RF envelope detection receiver architecture, it is assumed that the LP-WUS occupies 2N subcarriers. In addition, in the exemplary architecture, the LP-WUS bit is used to trigger the waveform selection That is, each OFDM symbol uses OFDM-OOK to perform the target spectrum of the ON or OFF state pulse shape of OOK modulation. It should be noted that the vector z can also represent the spectrum of the OOK bit stream, which can be obtained using DFT to support DFT-OOK. Then, the target waveform z and the interference signal y can be used to dynamically design the LP-WUS to which N subcarriers are allocated. In an exemplary design, LP-WUS can be obtained as follows

[0143]

[0144] Among them, the matrix Formulated as Y = [y N-1 y N-2 …y N-M ] * , making is a shifted version of y with l leading zeros and N+l truncated elements; and Perform the conjugate transpose operation. In order to have a reliable design of x, the following constraint on M should be satisfied, that is, M≤N. This constraint ensures that there are enough degrees of freedom to find the exact solution for x. It should be noted that in Figure 20 In the example shown, N subcarriers (SC) are considered as guard bands. However, in an alternative example, Figure 20 The N-SC used as a guard band in can be considered as a part of LP-WUS, making The length of M can be selected to satisfy, for example, M≤2N.

[0145] It should be noted that the algorithm can easily support modulations other than OOK, such as BPSK, QPSK, QAM, OFDM, multiple parallel OOK channels, etc., by simply setting the target waveform vector z to the DFT of the desired modulation symbol. It should also be noted that compared to the above scheme, this scheme saves the required frequency resources that LP-WUS would otherwise have to occupy alone. For example, LP-WUS only requires frequency resources on one edge of the carrier, allowing information / data for other UEs to occupy the remaining spectrum. However, it should be noted that if the amount of available information / data for other UEs is not sufficient to occupy the rest of the spectrum, i.e., it is not allocated to LP-WUS and is scheduled on frequency resources other than those required by LP-WUS, the network can fall back to a dual spectrum allocation scheme to generate the required signal at a fixed IF frequency after envelope detection at the receiver.

[0146] Figure 21 An exemplary OFDM-based transmitter architecture 2100 is shown, enabling LP-WUS dynamic design with single spectrum allocation.

[0147] exist Figure 22 In

[15] , a diagram of the effect of the envelope detection operation applied to both RF and IF envelope detection on the signal spectrum is presented. As previously mentioned, the envelope detection operation results in the convolution of the spectrum with its own complex conjugate. The integration of the product of the overlapping spectra produces an envelope spectrum at a specific frequency offset, for example, IF2. The LP-WUS can then be allocated a narrow bandwidth at the edge of the serving NR carrier, for example, 2 PRBs with a bandwidth of 360kHz. The values ​​of the subcarriers within the allocated bandwidth allocated to the LP-WUS can be selected to eliminate interference from other subcarriers within the NR carrier. The goal of the LP-WUS design is then to generate the desired / target OOK signal centered around, for example, IF2, with sufficient guard band to support cost and integration efficient implementation of the baseband BPF, thereby achieving good in-band selectivity for the LP-WUS.

[0148] Figure 22 is a graphical illustration of an envelope detection operation 2200 on the frequency spectrum of a signal.

[0149] In fact, when the receiver is at its minimum sensitivity point, the received LP-WUS RF signal is typically well below the receiver's thermal noise floor. For a single OOK signal after envelope detection, the embodiment technique can maximize the envelope signal during the ON period of the OOK signal (the OFF period of the signal simply clears the LP-WUS frequency resource). In this case, the algorithm becomes very simple: x is simply a scaled version of the interference signal y frequency-shifted to the location of the LP-WUS. In addition, the scaling factor is the information modulated on the IF subcarrier after envelope detection. The freedom of this scaling factor supports virtually any modulation scheme, such as OOK, BPSK, QPSK, QAM, etc.

[0150] The following analysis compares the minimum sensitivity of a conventional OOK design and a co-generated IF envelope OOK design. It shows that the co-generated IF envelope OOK design provides an ideal sensitivity that is 3dB higher than the conventional OOK design.

[0151] Figure 23(a) shows the reference receiver architecture of an RF envelope detection receiver for a traditional OOK design. The RF signal from the antenna is first filtered by an RF filter (usually broadband) and then optionally amplified by a low noise amplifier (LNA). The signal is then filtered by a narrowband RF filter to contain only the OOK signal and AWGN noise, as shown in Figure 23(b). The signal then passes through an RF envelope detector and is low-pass filtered. Finally, the signal is sampled by an analog-to-digital converter (ADC) to extract the WUS message.

[0152] Let x represent the OOK signal, n represent the AWGN noise, and the input of the envelope detector be y = x + n. The output of the envelope detector is:

[0153] |y| 2 =|x| 2 +|n| 2 +2*Real[x*n * ]

[0154] The desired signal is |x| 2 , whose power is E[|x| 4 ]. The envelope noise is |n| 2 +2*Real[x*n * ]≈|n| 2 ,Since the RF noise is usually much higher than the OOKRF signal at the sensitivity limit, E[|n| 2 ]>>E[|x| 2], therefore, the cross product between the OOKRF signal and the RF noise is much smaller than the self-product of the RF noise and can be ignored. RF noise self-product |n| 2 has a DC component, which can be eliminated by digital signal processing. The embodiment technique can calculate the residual interference of the OOK signal as the variance of the envelope signal generated by the noise envelope, that is, |n| 2 ,

[0155] E[(|n| 2 -E[|n| 2 ]) 2 ]=E[|n| 4 ]-(E[|n| 2 ]) 2 =σ 4

[0156] Among them, σ 2 is the variance or power of the AWGN noise.

[0157] Figure 23(c) shows the reference receiver architecture for collaboratively generated IF envelope OOK. It is identical to conventional OOK up to the RF envelope detector, except for the absence of a narrowband RF filter compared to Figure 23(a). After RF envelope detection, the IF envelope signal is demodulated to baseband by a complex demodulator. After low-pass filtering, the complex baseband signal is sampled into the digital domain by an ADC. In the digital domain, a circuit is implemented to adjust the local oscillator phase of the complex demodulator to minimize the correlation between the real and imaginary parts of the complex baseband signal. A selector selects the path with the stronger signal to extract the WUS message.

[0158] Figure 23(d) shows the RF spectrum of the signal at the input of the envelope detector. The signal is divided into three parts based on its frequency. The high frequency side is the WUS signal x WUS And the corresponding RF noise n1. The low frequency side is the background flow signal x', which will be mixed with the WUS signal to produce the desired envelope signal at IF and its corresponding RF noise n1. In the middle is the other background flow signal x NR and its corresponding RF noise n3. The total input to the envelope detector can be expressed as:

[0159]

[0160] Among them, ω IF is the desired IF envelope frequency. After envelope detection and complex demodulation, the signal becomes After low-pass filtering, all envelope signals that are not at the desired IF frequency are removed. The remaining signal is:

[0161]

[0162] The desired signal is x WUS *x′ * , the noise envelope is:

[0163] x WUS *n2 * +n1*x′ * +n1*n2 * ≈n1*n2 *

[0164] Since at the sensitivity limit, the RF noise is much higher than the OOK or background traffic signal, E[|n1| 2 ]、E[|n2| 2 ]>>E[|x wuS | 2 ], E[|x′| 2 ], so the cross terms between RF noise and WUS and background flow signals can be ignored.

[0165] During the ON period of OOK modulation, x WUS =x′, then the required signal is |x′| 2 , the noise envelope is n1*n2 * Assuming that the power spectral density of WUS remains the same as that of the background flow signal, the required IF envelope signal |x′| 2 Compared with the traditional OOK case |x| 2 The levels are the same, that is, the required signal power is E[|x′| 4 ]≈E[|x| 4 ]. It should be noted that the desired signal is a real number, while the noise envelope is a complex number. As shown in Figure 23(c), by carefully adjusting the demodulation phase, the desired signal will only appear in one of the two baseband signal branches. Therefore, the embodiment technology can eliminate the imaginary part of the noise envelope. Therefore, the noise envelope becomes Among them, n1 and n2 are independent AWGN, and their power is

[0166]

[0167] This is only half of the traditional OOK case. Therefore, the collaboratively generated IF envelope OOK design improves SNR by 3dB and sensitivity by 3dB.

[0168] An intuitive way to understand the resulting sensitivity difference during envelope detection is that in the case of traditional OOK, the noise is completely autocorrelated, whereas in the case of co-generated IF envelope OOK, the two noise signals are independent of each other. It is worth noting that if phase correction is not implemented in the reference radio architecture of Figure 23(c), the worst-case scenario is that the two baseband signal branches have approximately the same strength. In this case, the 3dB sensitivity advantage is lost because the desired signal power is evenly split between the two branches.

[0169] Figure 23(a) shows a reference radio architecture 2300 for conventional OOK. Figure 23(b) shows the RF spectrum 2320 of the input signal to the envelope detector for a conventional OOK design. Figure 23(c) shows a reference radio architecture 2340 for a collaboratively generated IF envelope OOK design. Figure 23(d) shows the RF spectrum 2380 of the input signal to the envelope detector for a collaboratively generated IF envelope OOK design and a diagram of the process for generating the IF envelope signal.

[0170] Furthermore, perfect spectrum selection for WUS signals is often not possible in RF envelope detection. The narrowband RF filter shown in the reference radio architecture of Figure 23(a) is expensive to implement. Without such a narrowband RF filter, the co-generated IF envelope OOK design offers a more significant sensitivity advantage. While conventional OOK is interfered with by the entire AWGN allowed in by the RF filter, the co-generated IF envelope OOK design is in-band selective and is not interfered with by the additional AWGN. For example, if the RF bandwidth is 20 MHz and the WUS allocation is 2.9 MHz, ideally, the difference is equivalent to an additional 8 dB sensitivity advantage for the co-generated IF envelope design.

[0171] Feasibility of IF / Baseband Envelope Detection

[0172] As mentioned previously, the use of a low-precision and low-stability LO in the IF / baseband envelope detection architecture creates uncertainty in the IF / baseband frequency occupied by the LP-WUS. This uncertainty requires sufficient guard bands around the LP-WUS to suppress interference from any signals multiplexed on adjacent subcarriers, which may not be a resource-efficient solution.

[0173] The dual spectrum allocation scheme may not provide any resource efficiency for IF / baseband envelope detection receiver architectures, as it requires sufficient guard bands around each single allocated spectrum, comparable to the bandwidth allocated by LP-WUS, to eliminate interference. However, it can relax the requirements on the IFBPF characteristics, for example, for IF envelope detection receiver architectures, which may reduce implementation costs and / or improve integration capabilities.

[0174] On the other hand, the dynamic LP-WUS design described above can be used to provide a resource-efficient solution by generating the target signal at a specific / fixed and accurate frequency after envelope detection, where the guard band around the NR carrier can be reused, i.e., minimizing the requirement for any additional resources needed to mitigate LO uncertainty. Furthermore, this design supports reduced IFBPF design requirements, i.e., for IF envelope detection receiver architectures. Figure 24 A scheme for an IF envelope detection receiver architecture is shown, where a front-end (FE) RF matching network / BPF is used to select the desired NR band. An IFBPF is then used at the IF to select the entire desired serving carrier, and IF envelope detection is used to convert the signal to baseband. A dynamic LP-WUS design then generates the target / desired OOK signal at or centered at a specific (and accurate) frequency (IF2) with sufficient guard band for BB filtering. It should be noted that the BB filter design requirements should be more manageable than the IFBPF design requirements, as the expected IF2 center frequency is lower than the IF.

[0175] Figure 24 is a graphical representation of the feasibility / advantages 2400 of a dynamic LP-WUS design for an IF envelope detection receiver architecture.

[0176] Feasibility of achieving higher / adaptive data rates

[0177] Both the dual spectrum allocation scheme and the dynamic LP-WUS design scheme can support data rates higher than the basic data rate supported by OFDM-OOK, such as 14 kbps at 15 kHz SCS and 28 kbps at 30 kHz SCS. In a first example, a data-dependent design can be considered in the dual spectrum allocation scheme, where the target signal after envelope detection is a spectrum of a set / sequence of L bits determined by the data stream and calculated using, for example, DFT or a lookup table. The LP-WUS at RF on both sides of the carrier spectrum is then designed to obtain the target signal after envelope detection. The number of bits L represents the number of bits to be carried / transmitted within any OFDM symbol duration, so the supported data rate can be determined as 14×L kbps at 15 kHz SCS or 28×L kbps at 30 kHz SCS. In this example, the LP-WUS at RF can be dynamically determined / calculated or obtained from a lookup table based on the incoming data stream.

[0178] In the second example, the target signal / waveform z of the dynamic LP-WUS design is designed to achieve a higher data rate than the OFDM-OOK basic data rate using sequential or parallel bit streams. In the sequential bit stream, the target signal / waveform z is determined as the spectrum of a set / sequence of L bits determined by the incoming data stream and calculated using, for example, DFT or a lookup table. On the other hand, in Figure 25 In the example of parallel bit streams, the target signal / waveform z is divided into L parts, where each part includes, for example, M / L samples / SC representing the frequency spectrum, such as ON / OFF pulse shapes or waveforms in the frequency domain of one of the L data streams obtained by transforming the incoming original LP-WUS data stream into L parallel data streams. Similar to the first example, the effective data rate in these two alternatives can be determined to be 14×L kbps at 15 kHz SCS or 28×L kbps at 30 kHz SCS.

[0179] Figure 25 is a diagram illustrating parallel bitstream support / generation 2500 designed for an IF envelope detection receiver architecture using dynamic LP-WUS.

[0180] In the third example, for Figure 26 An exemplary dual spectrum allocation scheme may consider a parallel channel design, where the incoming bit stream is split into two parallel streams, e.g., OOK modulated. After envelope detection and taking into account an auxiliary signal on the other edge of the carrier spectrum, the incoming bits in each stream may be used to trigger an LP-WUS design corresponding to a desired, e.g., ON / OFF pulse shape or waveform in the frequency domain. Figure 26 Using the example in and assuming OOK modulation, the effective raw data rate can be determined to be 14×2 kbps at 15 kHz SCS or 28×2 kbps at 30 kHz SCS. Figure 26 The scheme illustrated in can also be extended to L parallel streams. In addition, each stream can also consider bit grouping or DFT processing as described in the first example. Figure 26 As can be seen in , this scheme may not be spectrum efficient due to the guard band requirement around each LP-WUS, but it can simplify the LP-WUS design.

[0181] Figure 26 is an exemplary frequency response 2600 of a single OFDM symbol under a parallel LP-WUS design with dual spectrum allocation.

[0182] In a fourth example, the target signal / waveform z of the dynamic LP-WUS design is designed so that every L consecutive bits in the incoming LP-WUS bitstream are used to trigger 2 in the target signal / waveform z. LOne of the frequency segments. Each segment consists of M / 2 L Sample / SC composition can carry ON or OFF pulse shape or waveform in the frequency domain. This design can be used to support 2 L -FSK modulation scheme provides services for LP-WUR, as described above.

[0183] Receiver Architecture and Processing

[0184] Figure 27 An example of a simplified low-power RF envelope detection receiver architecture that can be used to receive an LP-WUS generated according to any of the methods discussed above is shown. The main blocks in the architecture include front-end RF filters or matching networks for out-of-band and / or adjacent channel interference suppression. It should be noted that the embodiment signal design scheme reduces the requirements for RF filtering, that is, very high Q filtering may not be required, especially for the illustrated RF envelope detection architecture. In addition, they enable frequency multiplexing of the LP-WUS with other NR signals and / or channels. An LNA is optionally considered to improve the sensitivity of the LP-WUS. The first RF envelope detector is used to down-convert the RF signal to baseband. Then, a narrowband BPF centered at a fixed IF frequency determined by the LP-WUS design can be used for LP-WUS channel / spectrum selection and in-band interference suppression. Then, a self-mixing BB envelope detector can be used, for example, using an N-PPM type mixer as discussed above for the dual uncertain IF architecture. Alternatively, the BPF and LP-WUS channel / spectrum downconversion to baseband can be achieved with a low-frequency LO and an N-PPM type mixer followed by an LPF, where Figure 27 and Figure 28 The example shown in uses 2-PPM. In another alternative, a complex mixer with a low-frequency LO can be used to center the LP-WUS channel at DC, and a narrowband LPF can be used instead of a BPF for LP-WUS channel selection and in-band interference suppression.

[0185] Figure 27 is an exemplary RF envelope detection receiver architecture 2700 supporting dual spectrum allocation and dynamic LP-WUS design schemes.

[0186] Figure 28 Another example of a simplified low power IF envelope detection receiver architecture that can be used to receive a LP-WUS generated according to any of the methods discussed above is shown. Figure 27An exemplary architecture is presented in FIG. The main blocks of the architecture may include any one of a front-end RF filter or matching network, an LNA, a narrowband BPF and / or LPF, a self-mixing / BB envelope detector, and a mixer with a low-frequency LO. In addition, in contrast to the first RF envelope detector, a first IF envelope detector is considered, in which the input IF signal is filtered using an IFBPF with a bandwidth corresponding to the serving NR carrier bandwidth after being converted from RF using a mixer and a low-precision LO. The mixer can be a complex mixer or a mixer combined with an image rejection filter (e.g., a front-end matching network or RF filter). In addition, an IF amplifier can optionally be considered to improve LP-WUR sensitivity.

[0187] Figure 28 is an exemplary IF envelope detection receiver architecture 2800 supporting dual spectrum allocation and dynamic LP-WUS design schemes.

[0188] In another example of a simplified low-power receiver architecture, Figure 27 and Figure 28 The exemplary architecture illustrated in can be reused to support receiving multiple (e.g., L) parallel streams of, for example, OOK modulated bits. Figure 29 The reuse of an RF envelope detection receiver architecture is illustrated in , where two parallel streams are considered, each with a data rate of, for example, 14 kbps at, for example, 15 kHz SCS.

[0189] Figure 29 is an exemplary RF envelope detection receiver architecture 2900 supporting dual spectrum allocation with parallel bit streams and a dynamic LP-WUS design scheme.

[0190] Supporting the signal design process of the embodiment

[0191] In this section, the signaling and processes of the embodiment signal design scheme are achieved by making appropriate trade-offs between resource utilization efficiency, UE energy saving gain and LP-WUS decoding and / or detection performance. The trade-off can take into account any of the channel qualities, such as path loss and / or fading, intra-cell interference and inter-cell interference. For example, the UE can configure its LP-WUR to switch from the RF envelope detection architecture to the IF / BB envelope detection architecture to improve the detection / decoding performance of the LP-WUS at the expense of increasing the power consumption of the LP-WUR. In another example, due to the presence of interference at the carrier edge, the UE can configure its LP-WUR to switch from the RF envelope detection architecture to the IF / BB envelope detection architecture to improve the detection / decoding performance of the LP-WUS at the expense of increasing the power consumption of the LP-WUR and / or reducing resource utilization.

[0192] In one embodiment, Figure 30As shown, the UE is equipped with LP-WUR, which can dynamically switch between RF envelope detection and IF / BB envelope detection architectures based on network support. In the first step, the UE receives the LP-WUS configuration using either RRC or system information signaling. The LP-WUS configuration can include any of the following:

[0193] Indication of support for post-ED signaling designs.

[0194] Front envelope detection (ED) signals, such as LP-WUS and in-band interference signals, bandwidth.

[0195] • Post-ED signal, such as LP-WUS, center frequency (such as IF) and bandwidth.

[0196] • LP-WUS transmission data rate, e.g., 14 kbps or 28 kbps, which may be determined based on the indicated SCS and support for DFT precoding (i.e., DFT-OOK).

[0197] LP-WUS coding scheme and coding rate, such as Manchester coding with a coding rate of 1 / 2.

[0198] In the second step, the UE determines the network's support for the post-ED signaling design. In the third step, the UE switches its RF envelope detection LP-WUR architecture based on the determined network's support. In one example, if the network's support is determined as part of the received system information configuration, the UE switches its RF envelope detection LP-WUR architecture. Otherwise, the UE switches its IF / BB envelope detection LP-WUR architecture, i.e., the network's support is not determined. In the fourth step, the UE determines the center frequency (e.g., IF) and bandwidth of the LP-WUS based on the received configuration. In the fifth step, the UE configures the baseband circuitry of the LP-WUR, e.g., filters and / or mixers and / or low-frequency LO, to use the determined center frequency and bandwidth to suppress in-band interference and convert the LP-WUS to baseband, i.e., a DC-centered LP-WUS. In the sixth step, the LP-WUR is used to monitor the LP-WUS according to the configured data rate and coding scheme / rate.

[0199] In an alternative to the third step, the UE switches its RF envelope detection LP-WUR architecture based on the determined network support and LP-WUR capabilities. In one example, if the network support is determined and the bandwidth of the RF front-end matching network and / or BPF supports the configured / received pre-ED signal bandwidth, the UE switches its RF envelope detection LP-WUR architecture. Otherwise, the UE switches its IF / BB envelope detection LP-WUR architecture, i.e., if the network support is determined, but the bandwidth of the RF front-end matching network and / or BPF does not support the configured / received pre-ED signal bandwidth. In addition, the UE switches its IF / BB envelope detection LP-WUR architecture based on the network not supporting the post-ED signaling design.

[0200] Figure 30 30 is an exemplary flow chart illustrating a process 3000 in which a UE dynamically switches between RF and IF / BB envelope detection architectures based on network support. The UE receives an LP-WUS configuration using RRC and / or system information (step 3002). The UE determines network support for a post-ED signaling design (step 3004). If the network does not support post-ED signaling, the process 3000 proceeds from step 3006 to step 3008, where the UE uses an IF / BB envelope detection LP-WUR architecture to handle in-band selectivity. If the network supports post-ED signaling, the process 3000 proceeds from step 3006 to step 3010, where the UE switches the RF envelope detection architecture of the LP-WUR to directly convert the RF signal to BB. Next, the UE determines the LP-WUS center frequency (low IF) and BW based on the received configuration (step 3012). Next, the UE configures any one of the BBBPF, passive mixer, low-frequency LO, and BBLPF for the LP-WUR based on the determined LP-WUS low IF and BW to suppress in-band interference (step 3014). Next, the UE uses the LP-WUR to monitor, decode, or detect the LP-WUS based on the configured data rate, coding scheme, and coding rate (step 3016), after which process 3000 can continue and return to step 3002.

[0201] The indication of post-ED signaling design support may be used to indicate network support for any of the following:

[0202] Through proper signal design, the need for a mixer-first architecture (i.e., IF / BB envelope detection architecture) is reduced, achieving extreme LP-WUR power savings gains.

[0203] LP-WUR with RF envelope detection architecture reduces front-end requirements for matching networks and / or BPFs.

[0204] The LP-WUR of the IF envelope detection architecture reduces the requirements on the IFBPF, which can make the power consumption of the relatively high IF LP-WUR architecture lower than that of the low IF architecture.

[0205] The pre-ED signal bandwidth may or may not be equal to the serving NR carrier bandwidth and may be transmitted to the LP-WUR as any of the following:

[0206] • An indication / index of one bandwidth configuration out of a limited set of bandwidth configurations (e.g., {5 MHz, 10 MHz, 15 MHz, 20 MHz}).

[0207] • The number of PRBs of the default / configured SCS, or a pair of number of PRBs and the SCS considered.

[0208] An indication of the usage of the serving NR carrier bandwidth.

[0209] The post-ED signal bandwidth can be indicated to one or more LP-WURs using any of the following:

[0210] • An indication / index of one bandwidth configuration out of a limited set of bandwidth configurations (e.g., {360 kHz, 720 kHz, 1.44 MHz, 2.88 MHz, ...}).

[0211] • The number of PRBs of the default / configured SCS, or a pair of number of PRBs and the SCS considered.

[0212] • The number of SCs of the default / configured SCS, or a pair of numbers of an SC and the SCS under consideration.

[0213] · Default / configured SCS PRB index list

[0214] • List of PRB indices and the SCSs considered.

[0215] The rear ED signal center frequency may be based on the rear ED signal bandwidth configuration (e.g., PRB index list) or according to a preconfigured formula involving, for example, the bandwidths of the front ED (B1) and rear ED (B2) signals (e.g., IF = B1-B2-B Offset , where B offset The following information elements may be indicated to one or more LP-WURs:

[0216] • An indication / index of one of a limited set of center frequencies (IF) (e.g., {4.28 MHz, 3.56 MHz, 2.12 MHz, ...}).

[0217] • With respect to the default center frequency (IF), an indication / index of one of a limited set of center frequency (IF) offsets (e.g., {720 kHz, 1.44 MHz, 2.88 MHz, ...}).

[0218] A pair of PRB and SC index, i.e. the index of the SC within the PRB indicated by the index.

[0219] Number of PRBs of the default / configured SCS with respect to the default center frequency (IF).

[0220] Number of SCs of the default / configured SCS with respect to the default center frequency (IF).

[0221] In another embodiment, Figure 31 As shown, the UE is equipped with LP-WUR, which can dynamically switch between RF envelope detection and IF / BB envelope detection architectures based on network support and received signal strength. In the first step, the UE receives the LP-WUS configuration using either RRC or system information signaling. The LP-WUS configuration can include any of the following:

[0222] Indication of support for post-ED signaling designs.

[0223] Received signal strength threshold.

[0224] Low power reference signal and / or synchronization signal configuration.

[0225] Pre-ED signals, such as LP-WUS and in-band interference signals, bandwidth.

[0226] Post-ED signals, such as LP-WUS, center frequency (such as IF) and bandwidth.

[0227] • LP-WUS transmission data rate, e.g., 14 kbps or 30 kbps, which may be determined based on the indicated SCS and support for DFT precoding (i.e., DFT-OOK).

[0228] LP-WUS coding scheme and coding rate, such as Manchester coding with a coding rate of 1 / 2.

[0229] In the second step, the UE determines the network's support for the post-ED signaling design. In the third step, the UE measures the received signal strength using the low power reference signal configuration. In the fourth step, the UE determines the low power reference signal received signal strength greater than the configured threshold. In the fifth step, the UE switches its RF envelope detection LP-WUR architecture based on the determined network support and received signal strength. In the sixth step, the UE determines the center frequency (e.g., IF) and bandwidth of the LP-WUS based on the received configuration. In the seventh step, the UE configures the baseband circuitry of the LP-WUR, e.g., filters and / or mixers and / or low frequency LO, to use the determined center frequency and bandwidth to suppress in-band interference and convert the LP-WUS to baseband, i.e., a DC-centered LP-WUS. In the eighth step, the LP-WUR is used to monitor the LP-WUS according to the configured data rate and coding scheme / rate.

[0230] In an alternative to the fourth step, the UE determines a low power reference signal received signal strength that is less than a configured threshold. Subsequently, in a fifth step, the UE switches its IF / BB envelope detection LP-WUR architecture based on the determined network support and received signal strength.

[0231] Figure 3131 is an exemplary flow chart illustrating an embodiment process 3100 of a UE dynamically switching between RF and IF / BB envelope detection architectures based on network support and RSRP measurement. The UE receives an LP-WUS configuration using RRC and / or system information (step 3102). Next, the UE determines network support for a post-ED signaling design (step 3104). If not supported in step 3106, the process 3100 proceeds to step 3108, where the UE uses an IF / BB envelope detection LP-WUS architecture to handle in-band selectivity. If support for a post-ED signaling design is present in step 3106, the process 3100 proceeds to step 3110, where the UE measures RSRP based on the received LP-RS / SS configuration and compares it to a threshold T. Next, in step 3112, if the RSRP is not greater than the threshold T, the process 3100 proceeds to step 3108, and if the RSRP is greater than the threshold, the process 3100 proceeds to step 3114, where the UE switches the RF envelope detection architecture of the LP-WUR to directly convert the RF signal to BB. Next, the UE determines the LP-WUS center frequency (low IF0) and BW based on the received configuration (step 3116). Next, the UE configures any one of the BBBPF, passive mixer, low frequency LO and BBLPF for the LP-WUR to suppress in-band interference based on the determined LP-WUS low IF and BW (step 3118). Next, the UE uses the LP-WUR to monitor, decode or detect the LP-WUS based on the configured data rate, coding scheme and coding rate (step 3120), after which the process 3100 can continue back to step 3102.

[0232] The low power reference signal and / or synchronization signal configuration may include any of the following:

[0233] Indication of whether the transmission is periodic or aperiodic

[0234] Transmission periodicity, which can be indicated as one of the following:

[0235] oThe index of a value from a preconfigured set of values

[0236] o The number of any of OFDM symbols, slots, subframes, and frames

[0237] In an aperiodic transmission scheme, the maximum period / duration between subsequent transmissions, which may be indicated as:

[0238] oThe index of a value from a preconfigured set of values

[0239] o The number of any of OFDM symbols, slots, subframes, and frames

[0240] A signal structure that may include any of one or more known sequences and a payload, wherein the payload may be characterized by any of:

[0241] oFixed or configurable variable size

[0242] oFixed or configurable length frame check sequence

[0243] In another embodiment, Figure 32 As illustrated, a UE in, for example, an RRC connected state is equipped with an LP-WUR that can dynamically switch between RF envelope detection and IF / BB envelope detection architectures based on network support and experienced interference levels. In a first step, the UE receives an LP-WUS configuration using either RRC or system information signaling. The LP-WUS configuration may include any of the following:

[0244] Indication of support for post-ED signaling designs.

[0245] • Configuration of reference signals that can be used to measure one or more interfering signals that may affect LP-WUS decoding / detection performance.

[0246] • Interference signal measurement criteria used to determine the suitability of post-ED signaling designs, such as the configured threshold value at which the interference signal strength on one edge of the carrier is greater than the interference signal strength on the other edge.

[0247] Pre-ED signals, such as LP-WUS and in-band interference signals, bandwidth.

[0248] Post-ED signals, such as LP-WUS, center frequency (such as IF) and bandwidth.

[0249] • LP-WUS transmission data rate, e.g., 14 kbps or 30 kbps, which may be determined based on the indicated SCS and support for DFT precoding (i.e., DFT-OOK).

[0250] LP-WUS coding scheme and coding rate, such as Manchester coding with a coding rate of 1 / 2.

[0251] In the second step, the UE determines the network's support for the post-ED signaling design. In the third step, the UE uses the reference signal configuration to measure the interference signal. In the fourth step, the UE determines that the post-ED signaling criteria are met, for example, the ratio of the interference signal strengths on the two edges of the carrier is between the first configuration threshold and the second configuration threshold. In the fifth step, the UE requests to enable post-ED signaling and switch its RF envelope detection LP-WUR architecture. In the sixth step, the UE determines the center frequency (e.g., IF) and bandwidth of the LP-WUS based on the received configuration. In the seventh step, the UE configures the baseband circuits of the LP-WUR, for example, filters and / or mixers and / or low-frequency LO, to use the determined center frequency and bandwidth to suppress in-band interference and convert the LP-WUS to baseband, i.e., a DC-centered LP-WUS. In the eighth step, the LP-WUR is used to monitor the LP-WUS according to the configured data rate and coding scheme / rate.

[0252] In an alternative to the fourth step, the UE determines that the post-ED signaling criteria are not met, for example, the ratio of the interference signal strengths at the two edges of the carrier is less than the first configured threshold or greater than the second configured threshold. Subsequently, in the fifth step, the UE switches its IF / BB envelope detection LP-WUR architecture without using post-ED signaling. Alternatively, in the fifth step, the UE requests the activation of post-ED signaling with a target center frequency (IF) lower than the currently configured center frequency, for example, requesting an increase in the guard band size at one or both edges of the carrier and switching its RF envelope detection LP-WUR architecture.

[0253] Figure 323200 is an exemplary flow chart illustrating an embodiment process 3200 in which a UE dynamically switches between RF and IF / BB envelope detection architectures based on network support and interference signal measurements. The UE receives an LP-WUS configuration using RRC and / or system information (step 3202). Next, the UE determines network support for a post-ED signaling design (step 3204). Next, in step 3206, if the network does not support the post-ED signaling design, the process 3200 proceeds to step 3208, where the UE uses an IF / BB envelope detection LP-WUS architecture to handle in-band selectivity. If, in step 3206, the network does not support the post-ED signaling design, the process 3200 proceeds to step 3210, where the UE measures interference signal strengths I1 and I2 and compares the ratio to thresholds T1 and T2 based on the received RS configuration. Next, in step 3212, if T2>I1 / I2>T1 is not true, the process 3200 returns to step 3208. If, in step 3212, T2>I1 / I2>T1 is true, the process 3200 proceeds to step 3214, where the UE switches the RF envelope detection architecture of the LP-WUR to directly convert the RF signal to BB. Next, the UE determines the LP-WUS center frequency (low IF) and BW based on the received configuration (step 3216). Next, the UE configures any one of the BBBPF, passive mixer, low frequency LO, and BBLPF for the LP-WUR to suppress in-band interference based on the determined LP-WUS low IF and BW (step 3218). Next, the UE uses the LP-WUR to monitor, decode, or detect the LP-WUS based on the configured data rate, coding scheme, and coding rate (step 3220), after which the process 3200 can continue back to step 3202.

[0254] In another embodiment, the base station enables dual spectrum allocation to transmit LP-WUS to LP-WUR. In the first step, the base station configures LP-WUS transmission parameters. The LP-WUS configuration may include any of the following:

[0255] Post-ED signaling using dual spectrum allocation design.

[0256] The set of frequency resources allocated for LP-WUS transmission.

[0257] LP-WUS target transmission data rate, such as 14 kbps or 28 kbps.

[0258] LP-WUS modulation / coding scheme and code rate, such as Manchester coding with a code rate of 1 / 2.

[0259] LP-WUS target baseband bandwidth and center frequency (IF) after envelope detection.

[0260] In the second step, the base station determines the first subset and the second subset of frequency resources based on the target baseband center frequency. In the third step, the base station determines the signal resources and guard band resources in the first subset of frequency resources and the second subset of frequency resources based on the target baseband bandwidth and the center frequency. In the fourth step, the base station allocates the first group of symbols to the signal resources of the first subset of frequency resources with a first power scaling factor. In the fifth step, the base station allocates the second group of symbols to the signal resources of the second subset of frequency resources with a second power scaling factor based on any one of the LP-WUS information bits, data rate, modulation scheme, coding scheme and coding rate. In the sixth step, the base station applies the signal generated in the frequency domain to the IFFT module to complete the OFDM transmission.

[0261] The set of frequency resources allocated for LP-WUS transmission is non-contiguous and may, for example, occupy two subsets of contiguous frequency resources on either side of a channel or carrier. The base station may also send one or more of the following information elements to the UE equipped with LP-WUS:

[0262] • Indication of post-ED signaling using, for example, a dual spectrum allocation design.

[0263] Post-ED signals, such as LP-WUS, center frequency (such as IF) and bandwidth.

[0264] LP-WUS data rate, such as 14 kbps or 28 kbps.

[0265] LP-WUS coding scheme and coding rate, such as Manchester coding with a coding rate of 1 / 2.

[0266] In another embodiment, the base station enables the collaboratively generated IF envelope to transmit the LP-WUS to the LP-WUR. In a first step, the base station configures the LP-WUS transmission parameters. The LP-WUS configuration may include any of the following:

[0267] Post-ED signal designed using collaboratively generated IF envelope.

[0268] • A first set of frequency resources allocated to LP-WUS transmissions.

[0269] LP-WUS target transmission data rate, such as 14 kbps or 28 kbps.

[0270] LP-WUS modulation / coding scheme and code rate, such as Manchester coding with a code rate of 1 / 2.

[0271] LP-WUS target baseband bandwidth and center frequency (IF) after envelope detection.

[0272] In a second step, the base station determines a first set of symbols allocated to the second set of frequency resources based on the configured target baseband bandwidth and center frequency. In a third step, the base station determines signal resources and guard band resources in the first set of frequency resources based on the configured target baseband bandwidth and center frequency and the determined second set of frequency resources. In a fourth step, the base station determines the second set of symbols and the power scaling factor based on any one of the following:

[0273] LP-WUS information bits,

[0274] The first set of symbols determined,

[0275] The configured LP-WUS target baseband bandwidth,

[0276] The configured LP-WUS baseband center frequency,

[0277] • The configured LP-WUS modulation / coding scheme and coding rate.

[0278] In the fifth step, the base station allocates the second set of symbols to the signal resources of the first set of frequency resources with the power scaling factor.In the sixth step, the base station applies the frequency domain generated signal to the IFFT module to complete the OFDM transmission.

[0279] The first set of symbols is determined based on the modulation and coding of a signal that may be transmitted, for example, via a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH). If the size of the second set of resources is sufficient to meet the target LP-WUS baseband bandwidth at the target baseband center frequency, then guard band resources may not be required.

[0280] Architecture

[0281] Figure 33 An exemplary 2-bit FSK receiver architecture 3300 utilizing a parallel OOK receiver provided by an embodiment is shown. The architecture 3300 includes an FSK signal 3302 input to each BPF 3304. The output of the BPF 3304 is input to a corresponding envelope detector 3306. The output of each pair of envelope detectors 3306 is input to a corresponding comparator 3308, and each comparator 3308 outputs a corresponding bit 1, bit 2, bit 3, or bit 4. In order to increase the data rate received by the FSK receiver, a higher modulation order, namely M-FSK (M≥4), can be considered. In Figure 33 The exemplary 2-bit FSK receiver shown, i.e. 4-FSK, is Figure 33As illustrated in the table, four different frequency resources are used to indicate two bits. In an FSK receiver, four bandpass filters centered on four frequencies on four different branches are used before envelope detection. The output of the envelope detector is then fed into a decision unit that decides one of four different two-bit combinations based on the relative strength / amplitude of the envelope detector output.

[0282] In RAN1#110bis-e, it was agreed to consider three types of receiver architectures for LP-WUR that are suitable for OOK modulation. These include an architecture with RF envelope detection, a heterodyne architecture with IF envelope detection, and a homodyne / zero IF architecture with baseband envelope detection. These architectures can also be applied to other modulation schemes, such as FSK, where an RFFSK receiver can be implemented with two parallel OOK receivers, where the RFBPF is used, for example. Figure 15 The IFFSK receiver can be centered on two different frequencies as shown in FIG, and can be realized by a mixer-first architecture and, for example, using, for example, Figure 18 The parallel OOK receiver is implemented with two IFBPFs centered at different frequencies as shown in FIG.

[0283] The RF envelope detection architecture achieves low power consumption by avoiding the use of a local oscillator (LO) and a phase-locked loop (PLL). The removal of the LO introduces another challenge to the RF envelope detection architecture, where suppressing interference from traditional NR signals / channels or other LP-WUS on adjacent subcarriers may require a very high-Q matching network and / or RFBPF. The implementation of a high-Q matching network and / or RFBPF may be expensive and / or bulky, for example, requiring off-chip components. The IF / baseband envelope detection architecture achieves low power consumption by reducing the accuracy and stability requirements of the LO. On the other hand, the use of a low-accuracy and low-stability LO in the IF / baseband envelope detection architecture creates uncertainty in the IF / baseband frequency occupied by the LP-WUS. This uncertainty requires sufficient guard band around the LP-WUS (i.e., the FSK modulated signal) to suppress interference from any signals multiplexed on adjacent subcarriers.

[0284] The above challenges are particularly relevant to high-order modulation FSK receiver architectures, which require more than two symbols (two frequencies), such as Figure 33 As shown in , these symbols can be used to support Figure 15 and Figure 18 Assuming FR1 operation with a subcarrier spacing (SCS) of 30kHz, the 2-FSK architecture shown in Figure 15 and Figure 18The data rate of the exemplary 1-bit FSK receiver architecture shown in is approximately 28 kbps.

[0285] Therefore, a solution is needed to help reduce power consumption, such as an envelope detection-based FSK receiver architecture that supports high data rates, i.e., high-order modulation M-FSK, where M > 2, without significantly impacting any of the receiver implementation cost, receiver implementation size, and network resource overhead. The following sections discuss these solutions.

[0286] Please note that Figure 33 The exemplary 4-FSK receiver architecture shown in uses 4 frequency resources to receive 2 bits. Figure 33 The 8-FSK receiver of the architecture shown in uses 8 frequency resources to receive 3 bits. That is, in general, such an M-FSK receiver architecture can be used and 2 N frequency resources to send N bits, where M=2 N This exponential increase in required frequency resources is undesirable for an M-FSK receiver architecture.

[0287] For a multi-bit FSK receiver that can achieve this goal, i.e., an M-FSK receiver (M>2), there are two potential multiplexing structures, which are introduced and described below.

[0288] 2N frequency multiplexing structure

[0289] N+2 frequency multiplexing structure

[0290] Each of these architectures will require 2N and N+2 non-contiguous frequency resources respectively and use M-FSK modulation (M=2 N ) receives N bits. This document describes procedures to support the operation of such a receiver architecture.

[0291] The modulation scheme is referred to as frequency shift keying (FSK) below, but other terms may also be considered, such as low-power coded modulation, resource-efficient OOK modulation, frequency-domain coded OOK modulation, differential OOK modulation, etc.

[0292] Example Receiver Architecture

[0293] 2N frequency multiplexing structure

[0294] In this structure, parallel use Figure 15 and Figure 18 Multiple 1-bit FSK receiver architectures are shown in

[15] to increase the supported data rate. Figure 34An exemplary 4-bit FSK (i.e., 16-FSK) receiver structure 3400 is shown in FIG. 3 , where only 8 RF / IFBPFs may be used instead of Figure 33 The 16 RF / IFBPFs required for the M-FSK architecture illustrated in FIG.

[0295] Receiver structure 3400 includes an FSK signal 3402 input to each of BPFs 3404. The output of each BPF 3404 is input to a corresponding envelope detector 3406. The outputs of envelope detectors 3406a, 3406b, 3406e, and 3406f are input to corresponding multi-input comparators 3408a, 3408b, 3408c, and 3408d. The output of each envelope detector 3406c and 3406d is input to each of multi-input comparators 3408a, 3408b, 3408c, and 3408d. The output of each multi-input comparator 3408 corresponds to bit 1, bit 2, bit 3, and bit 4.

[0296] On the transmitter side, the first bit (bit 1) is associated with frequency resources f1 and f2, where transmission on frequency f1 can be used to represent "0" and transmission on frequency f2 can be used to represent "1", and vice versa. Similarly, the second bit (bit 2), the third bit (bit 3), and the fourth bit (bit 4) can be associated with frequency pairs (f3, f4), (f5, f6), and (f7, f8), respectively.

[0297] On the receiver side, as Figure 34 As shown, the received signal is separated and passed through a set of RF / IF BPFs, where each pair is associated with a single bit. For example, the BPFs at f1 and f2 are used to detect the first bit (bit 1). The outputs of the BPFs then pass through an envelope detector, and each output pair (e.g., the outputs at frequencies f1 and f2) is fed into a comparator to determine the detection result, i.e., whether bit "0" or bit "1" is detected. A similar process is used for the detection of each of the other bits (i.e., bit 2, bit 3, and bit 4).

[0298] It is worth noting that Figure 34 The structure in can be viewed as a single 4-bit FSK receiver, two 2-bit FSK receivers, or four 1-bit FSK receivers receiving one / two / four different FSK signals multiplexed in the frequency domain, that is, one / two / four LP-WUS channels are enabled in parallel.

[0299] Therefore, with Figure 33 Required 2 N Compared with the architecture of frequency resources, Figure 34The architecture typically requires only 2N frequency resources to implement N bits per OFDM symbol, which alleviates the guard band problem, especially associated with low-power mixer-first IF envelope detector architectures with low-precision oscillators as discussed above. This still helps FSK receiver architectures based on RF envelope detectors, but their advantages may be smaller due to their use of expensive and / or bulky bandpass filters.

[0300] Next, another FSK receiver structure is discussed, which can further reduce the number of frequency resources required to transmit N bits using FSK-based modulation.

[0301] N+2 frequency multiplexing structure

[0302] In the FSK receiver structure described above, each bit is associated with a pair of frequency resources, where one frequency resource is used as a reference while the other is used for transmission, so each frequency resource alternates between being used as a reference and as a carrier to transmit information bits. In another structure, exemplified by Figure 34 In the 4-bit FSK receiver in [4], two frequency resources are selected to represent a fixed reference to another set of frequency resources, each of which is used as a carrier to transmit an information bit. Thus, the embodiment structure can support the transmission of N bits using only N+2 frequency resources, as opposed to the 2N required for the structure illustrated in [4].

[0303] On the transmitter side, the first bit (bit 1) is associated with frequency resource f1, where a transmission on frequency f1 can be used to represent a "1" and the absence of a transmission on frequency f1 can be used to represent a "0", and vice versa. To help an envelope detection-based FSK receiver estimate whether there is a transmission on frequency f1, a r0 Considering "zero" transmission, at frequency f r1 Similarly, the second bit (bit 2), the third bit (bit 3), and the fourth bit (bit 4) can be associated with frequencies f2, f3, and f4, respectively, while considering the frequencies f r0 and f r1 The "zero" and "coincidence" reference signals at .

[0304] On the receiver side, as Figure 34 As shown, the received signal is separated and passed through a set of RF / IFBPFs, where one dedicated BPF, for example, at f1, and two shared BPFs, for example, at f r0 and f r1 The BPF at the position is used to detect a single bit, such as the first bit (bit 1). The output of the BPF is then passed through an envelope detector, and each output tuple (e.g., frequency f1 and f r0 and fr1 The output on the 100 bit is fed to a multi-input (multi-threshold) comparator, such as a multi-threshold detection (M-Dec) unit, to determine the detection result, i.e., whether bit "0" or bit "1" is detected. A similar process is used for the detection of each of the other bits (i.e., bit 2, bit 3, and bit 4). The algorithm (e.g., decision criterion) that the M-Dec 3502 (e.g., multi-threshold comparator) unit may use is as follows: Figure 35 As shown, where E i Indicates that at frequency f i The signal at the output of the envelope detector after the BPF.

[0305] Then, Figure 34 The embodiment signal design and the corresponding 4-bit FSK receiver structure require only 6 frequency resources, which means that Figure 33 Compared with the 8 frequency resources of the structure in , the number of BPFs and frequency resources are saved by 38%. In addition, this means that Figure 33 Compared with the original M-FSK receiver structure in

[15] , it saves about 63% in the number of BPFs and frequency resources.

[0306] It is also worth noting that Figure 33 The structure is similar to Figure 34 The structure in can be viewed as a single 4-bit FSK receiver, two 2-bit FSK receivers, or four 1-bit FSK receivers receiving one / two / four different FSK signals multiplexed in the frequency domain, i.e., one / two / four LP-WUS channels are enabled in parallel. Figure 34 The structure in can generally be considered as a parallel OOK receiver with frequency domain coding, where, for example, two fixed reference frequencies are used to correctly estimate noise and / or interference.

[0307] N+1 frequency multiplexing structure

[0308] In this section, another receiver structure 3600 is disclosed, in which Figure 363600 illustrates a parallel 4-bit receiver that can receive N bits using only N+1 frequency resources based on a differential modulation / coding scheme. Receiver structure 3600 includes an FSK signal 3602 input to each of BPFs 3602, and the output of each of BPFs 3602 is input to a corresponding envelope detector 3604. The output of envelope detector 3604a is input to a multi-input comparator 3606a. The output of envelope detector 3604b is input to both multi-input comparators 3606a and 3606b. The output of envelope detector 3604c is input to both multi-input comparators 3606b and 3606c. The output of envelope detector 3604d is input to both multi-input comparators 3606c and 3606d. The output of envelope detector 3604e is input to multi-input comparator 3606d. Threshold 3606 is input to each of the multi-input comparators 3606. The output of each of the multi-input comparators 3606 is bit 1, bit 2, bit 3, and bit 4, respectively.

[0309] At the transmitter side, the reference signal is transmitted on the first resource f0, and the i-th bit (B i ) can be encoded using the i-th–1th coded bit to generate S according to the following formula i Bits:

[0310] S i =S i-1 ⊕B i ,i∈{1,2,…,N}

[0311] Where ⊕ represents a binary exclusive-OR operation. A “zero” or “consistent” transmission can be assigned to the reference signal on the first resource f0 to assist a differential receiver based on parallel envelope detection. The i-th coded bit S i and the i-th frequency resource f i Associated, where the frequency resource f i A valid transmission on can be used to represent a "1", that is, S i =1, and in the frequency resource f i No valid transmission can be used to represent "0", that is, S i =0, and vice versa.

[0312] On the receiver side, as Figure 36 As shown in the example, the received signal is separated and passed through a set of RF / IFBPF and envelope detector. Then, the envelope detector output / level E at frequency resource i is converted to i and the envelope detector output / level E at frequency resource (i-1) i-1 Compare to determine / detect information bit B using decision block / unit M-Dec i . Figure 37 The algorithm that can be used by the M-Dec unit 3702, such as the decision criterion, is shown in FIG. i and E i-1 Respectively represent the frequency resources f i-1 and f i The output of the envelope at .

[0313] In another variation, Figure 34 The receiver architecture illustrated in FIG can be modified to receive N+1 bits instead of the N bits described above. In this variation, the transmitter modulates two reference resources f r0 and f r1 , to transmit an additional information bit, such as bit 0, using 1-bit FSK modulation, while the remaining N bits are modulated differently, that is, the i-th bit is still modulated with the frequency resource f i associated with, where at frequency f i The transmission on the frequency f can be used to represent "1", and i No transmission on may be used to represent a "0" and vice versa. At the receiver side, a single threshold comparator may be used to decode an additional bit, eg, bit 0, associated with both reference resources. Figure 36 The detection criteria given in are still used for the initial decoding of bit i∈{1,2,…,N}, but the final value of bit i is determined based on the decoded bit 0, that is, depending on the value of bit 0, the initial decoding of bit i∈{1,2,…,N} may be reversed.

[0314] Supports the process of dynamic FSK modulation signal design

[0315] This section outlines the system, signaling, and procedures for using an embodiment of a resource-efficient FSK / OOK modulation and demodulation scheme and a corresponding low-power wake-up receiver architecture. The system can also implement resource-efficient frequency domain multiplexing of LP-WUS for multiple low-power FSK / OOK receivers.

[0316] Process at the transmitter

[0317] exist Figure 38In the embodiment process 3800 illustrated in the flowchart of , the base station processes the LP-WUS of a single LP-WUR using two fixed frequency resources as a reference. In a first step, the base station uses a high-level configuration to determine any of the following: a frequency set allocated to one or more LP-WUS transmissions, the number of bits multiplexed in an OFDM symbol, the number of LP-WUS multiplexed in the frequency domain, a first subset of frequency resources allocated to a "zero" reference signal, and a second subset of frequency resources allocated for a "consistent" reference signal (step 3802). In a second step, the base station allocates a first set of symbols for the "zero" reference signal with a first power scaling factor η1 (step 3804). In a third step, the base station allocates a second set of symbols for the "consistent" reference signal with a second power scaling factor η2 (step 3806). The base station then prepares N bits for parallel transmission and maps them to N subsets of frequency resources (step 3808). In a fourth step, the base station determines one or more frequency subsets to be allocated to one or more bits associated with one or more LP-WUS transmissions. In the fifth step, the base station allocates a third group of symbols or a fourth group of symbols to each frequency subset in the one or more determined frequency subsets based on the value / information of each bit in the one or more bits (e.g., a "0" bit or a "1" bit), and in the sixth step, the base station applies a third power scaling factor η3 or a fourth power scaling factor η4 to each frequency subset in the one or more determined frequency subsets based on the value / information of each bit in the one or more bits (e.g., a "0" bit or a "1" bit) (step 3810). In the seventh step, the base station applies the frequency domain generated signal to the IFFT module and completes the OFDM transmission (step 3812).

[0318] In an alternative to the first step, the base station determines the first subset and the second subset of frequency resources based on any one of a frequency set allocated for one or more LP-WUS transmissions configured (e.g., by a higher layer), the number of bits multiplexed in an OFDM symbol, and the number of LP-WUSs multiplexed in the frequency domain.

[0319] Different technical implementations may be considered for the first power scaling factor and the second power scaling factor in the second and third steps. In one technical implementation, the first power scaling factor is selected to be smaller than the second power scaling factor. In a second technical implementation, the first power scaling factor is selected to be zero.

[0320] Different technical implementations may be considered for the first group of symbols and the second group of symbols in the second step and the third step. In one technical implementation, the first group of symbols and the second group of symbols are selected to be the same. For example, the first group of symbols and the second group of symbols are selected based on one or more configured known sequences, such as Zadoff-Chu sequences. In another technical implementation, the first group of symbols and the second group of symbols are selected to be different. For example, the first group of symbols is selected as all-zero symbols, while the second group of symbols is selected based on one or more configured known sequences, such as Zadoff-Chu sequences. It is worth noting that the size of the group of symbols depends on the size of the allocated frequency resources, which may correspond to one or more allocated subcarriers, i.e., frequency resources. In addition, one or more known sequences may be selected for each transmission bit of each OFDM symbol based on, for example, any one of a randomization number initialized by a higher layer, an OFDM symbol index, a time slot number, and a subframe number.

[0321] In the fifth and sixth steps, the third set of symbols and the third power scaling factor are associated with a "0" bit, and the fourth set of symbols and the fourth power scaling factor are associated with a "1" bit.

[0322] Different technical implementations are contemplated for the third and fourth groups of symbols. In one technical implementation, the third and fourth groups of symbols are selected to be identical to the first and second groups of symbols, respectively. In another technical implementation, the third and fourth groups of symbols are selected to be identical but different from the first and second groups of symbols, wherein one or more known sequences in other configurations may be considered to determine each group of symbols. In another technical implementation, the third group of symbols is selected to be identical to the first group of symbols, and the fourth group of symbols is selected to be different from the second group of symbols based on a different one or more known sequences.

[0323] Different technical implementations may be considered for the third power scaling factor and the fourth power scaling factor. In one technical implementation, the third power scaling factor and the fourth power scaling factor are selected to be the same as the first power scaling factor and the second power scaling factor, respectively. In another technical implementation, the first power scaling factor and the third power scaling factor are selected to be the same, while the second power scaling factor and the fourth power scaling factor are selected to be different.

[0324] Different technical implementations may be considered to determine the frequency resource set and the distribution of the frequency resources as a subset of the reference signal and N parallel bits. The frequency resource set may be determined as N TA set of consecutive entities such as subcarriers (SCs) or physical resource blocks (PRBs). The size of the frequency resource (e.g., subset) allocated to a reference signal or a bit is configured to be, for example, N s SCs or PRBs, where the SCs or PRBs may include N G resources as guard bands. Then, the index of the first resource in the subset associated with / assigned to two reference signals can be configured or determined to be, for example and Furthermore, if the value is <I1, the index of the first resource in the subset associated with / assigned to the i-th bit can be determined to be (i - 1)N s + 1, otherwise it is determined to be (i + 1)f s + 1. In an alternative, the size of the frequency resource (e.g., subset) allocated to a reference signal or a bit can be configured to be, for example, N s SCs or PRBs, where the SCs or PRBs may not include N G resources as guard bands. Then, the index of the first resource in the subset associated with / assigned to two reference signals can be configured or determined to be, for example and Furthermore, if the value is <I1, the index of the first resource in the subset associated with / assigned to the i-th bit can be determined to be (i - 1)(N s + N G ) + 1, otherwise it is determined to be (i + 1)(N s + N G ) + 1. In another technical implementation, the total bandwidth B T can replace the total number of resources N T , the signal bandwidth B<{0000112}>can replace the number of subset resources N s , and the guard bandwidth B G can replace the number of guard band resources N G .

[0325] In another embodiment, the base station uses two randomized frequency resources as references to process the LP-WUS of a single LP-WUR. In a first step, the base station uses a high-level configuration to determine any of the following: a frequency set allocated to one or more LP-WUS transmissions, the number of bits multiplexed in an OFDM symbol, the number of LP-WUS multiplexed in the frequency domain, a first resource randomization pattern for a "zero" reference signal, and a second resource randomization pattern for a "consistent" reference signal. In a second step, the base station allocates a first group of symbols for the "zero" reference signal with a first power scaling factor η1. In a third step, the base station allocates a second group of symbols for the "consistent" reference signal with a second power scaling factor η2. In a fourth step, the base station determines a first subset and a second subset of frequency resources allocated to the "zero" reference signal and the "consistent" reference signal based on the configured first resource randomization pattern and the second resource randomization pattern, respectively. In a fifth step, the base station determines the remaining one or more frequency subsets to be allocated to one or more bits associated with one or more LP-WUS transmissions. In the sixth step, the base station allocates the third group of symbols or the fourth group of symbols to each frequency subset in the remaining one or more determined frequency subsets based on the value / information of each bit in the one or more bits (e.g., a "0" bit or a "1" bit). In the seventh step, the base station applies the third power scaling factor η3 or the fourth power scaling factor η4 to each frequency subset in the one or more determined frequency subsets based on the value / information of each bit in the one or more bits (e.g., a "0" bit or a "1" bit). In the eighth step, the base station applies the signal generated in the frequency domain to the IFFT module and completes the OFDM transmission.

[0326] The first resource randomization pattern and the second resource randomization pattern may consist of one or more of the following:

[0327] • A set of indices indicating the sequence of frequency resource subsets within the set of frequency resources allocated to one or more LP-WUS transmissions.

[0328] • A sequence to a known structure, such as one or more initialization seeds / parameters for PN or Zadoff-Chu.

[0329] • An offset or cyclic shift of the sequence from the initial sequence obtained using the configured initialization seed / parameters.

[0330] • Sequence length based on the length of the LP-WUS transmission and the number of frequency resource subsets within the pattern.

[0331] It should be noted that a single resource randomization pattern can be considered when "zero" and "consistent" reference signals alternate between two known / configured subsets of frequency resources. In addition, one or more initialization seeds / parameters and / or offsets or cyclic shifts can be determined based on any of the OFDM index, the timeslot number, and the subframe number at which the LP-WUS transmission begins. The pattern can be reset at the LP-WUS by detecting a known preamble indicating the start of LP-WUS reception.

[0332] exist Figure 39 In the alternative embodiment process 3900 illustrated in the flowchart of , the base station processes the LP-WUS of a single LP-WUR using differential modulation. In a first step, the base station uses a high-level configuration to determine any of the following: a frequency set allocated for LP-WUS transmission, the number of bits in an OFDM symbol, and a first resource for a "consistent" reference signal (e.g., resource 0) (step 3902). In a second step, the base station allocates a first set of symbols for the "consistent" reference signal with a first power scaling factor η1. In a third step, the base station determines one or more frequency subsets based on the configured frequency set, the number of bits in the OFDM symbol, and any one of the first resources. In a fourth step, the base station allocates a second set of symbols or a third set of symbols to the i-th frequency subset based on the value / information of the i-th bit (e.g., a "0" bit or a "1" bit) and the multiple sets of symbols allocated on the i-1 frequency subset. In a fifth step, the base station applies a second power scaling factor η2 or a third power scaling factor η3 to each frequency subset in the one or more determined frequency subsets based on the allocated one or more sets of symbols, e.g., the second set or the third set. In the sixth step, the base station applies the frequency-domain generated signal to the IFFT module and completes the OFDM transmission (step 3904). If there are more bits to process (step 3906), process 3900 proceeds to step 3908, where the base station moves to the i-th bit B_i, so that S_i = S_(i-1) XOR B_i, where S_(i-1) is the previous state bit. If S_i is "0", zero power is transmitted at F_i, and if S_i is "1", full power is transmitted at F_i. If there are no more bits in step 3906, the combined FSK symbol is transmitted.

[0333] Process at the Low Power Receiver

[0334] exist Figure 40 In the embodiment process 4000 illustrated in the flowchart of FIG, the UE uses two fixed frequency resources as references to process the LP-WUS. In the first step, the UE (e.g., a higher layer) configures the LP-WUS using any of the following information / configurations received as part of any RRC signaling and system information (step 4002):

[0335] a set of frequencies allocated to one or more LP-WUS transmissions,

[0336] The number of bits multiplexed in an OFDM symbol,

[0337] The number of LP-WUS multiplexed in the frequency domain,

[0338] a first subset of frequency resources allocated to a "zero" reference signal,

[0339] • A second subset of frequency resources allocated for "coincident" reference signals.

[0340] In a second step, the UE determines one or more frequency subsets to be allocated to one or more bits associated with its LP-WUS transmission. In a third step, the LP-WUR determines a first threshold T using signals received on the first frequency resource subset. i , e.g., an estimated noise level. In a fourth step, the LP-WUR determines a second threshold T2 using the signals received on the second subset of frequency resources, e.g., an estimate of interference power and channel fading level (step 4004). In a fifth step, the LP-WUR uses the determined first threshold T1 and second threshold T2, and one or more signal levels E i to detect one or more bits (step 4008).

[0341] In the second step, the determined one or more frequency subsets, as well as the first and second subsets of frequency resources, may constitute only a portion of the frequency set allocated for one or more LP-WUS transmissions, i.e., the remaining portion may be allocated to other UEs. Furthermore, the first and second subsets of frequency resources may be shared with other UEs. In one technical implementation, the one or more frequency subsets are determined based on a configured UE ID or a configured UE group ID.

[0342] In one technical implementation of the fifth step, if the determined signal level E i The absolute difference between the first threshold value and the signal level E is less than the signal level E. i and the determined second threshold, a bit "0" is detected / determined. Otherwise, a bit "1" is detected / determined.

[0343] In another embodiment, the UE uses two randomized frequency resources as references to process the LP-WUS. In a first step, the UE (e.g., higher layers) configures the LP-WUS using any of the following information / configurations received as part of any RRC signaling and system information:

[0344] a set of frequencies allocated to one or more LP-WUS transmissions,

[0345] The number of bits multiplexed in an OFDM symbol,

[0346] The number of LP-WUS multiplexed in the frequency domain,

[0347] a first resource randomization pattern for a "zero" reference signal,

[0348] • A second resource randomization pattern for "uniform" reference signals.

[0349] In a second step, the UE determines a first subset and a second subset of frequency resources allocated for a "zero" reference signal and a "consistent" reference signal based on the configured first resource randomization pattern and the second resource randomization pattern, respectively. In a third step, the UE determines the remaining one or more frequency subsets to be allocated to one or more bits associated with its LP-WUS transmission. In a fourth step, the LP-WUR determines a first threshold T1 using the signal received on the first subset of frequency resources, for example, an estimated noise level. In a fifth step, the LP-WUR determines a second threshold T2 using the signal received on the second subset of frequency resources, for example, an estimate of interference power and channel fading level. In a sixth step, the LP-WUR determines one or more signal levels E using the one or more signals received on the determined remaining one or more frequency subsets. i In the seventh step, the LP-WUR uses the determined first threshold value T1 and second threshold value T2, and one or more signal levels E i To detect one or more bits.

[0350] In another embodiment, Figure 41 As illustrated, the UE processes the LP-WUS using one frequency resource as a reference. In the first step, the UE (e.g., a higher layer) configures the LP-WUS using any of the following information / configurations received as part of any RRC signaling and system information:

[0351] a set of frequencies allocated to one or more LP-WUS transmissions,

[0352] The number of bits multiplexed in an OFDM symbol, e.g., N,

[0353] a first resource for a "coincidence" reference signal,

[0354] In a second step, the UE determines one or more frequency subsets to be allocated to one or more bits associated with its LP-WUS transmission based on the configured resource set, the first resource, and the number of multiplexing bits. In a third step, the LP-WUR uses the signal received on the first resource to determine a signal level E0, e.g., an input to a first decision logic M-Dec, such as Figure 37 In a fourth step, the LP-WUR uses the one or more signals received on the determined one or more frequency subsets to determine one or more signal levels E i (Step 4104). In the fifth step, LP-WUR uses the determined E i-1 and E i Signal level as the iM-Dec block (in Figure 37 The additional input of (i) is used to detect the i-th bit based on a preconfigured threshold (step 4108). In the sixth step, the fifth step is repeated until all bits are detected, for example, i=N.

[0355] Figure 42 An exemplary communication system 4200 is shown. The communication system 4200 includes an access node 4210 that serves user equipment (UE), such as UE 4220, having a coverage area 4201. In a first operating mode, communications to and from the UE pass through the access node 4210 having the coverage area 4201. The access node 4210 is connected to a backhaul network 4215 for connection to the Internet, operation and management, etc. In a second operating mode, communications to and from the UE do not pass through the access node 4210, however, the access node 4210 typically allocates resources to the UE for communication when certain conditions are met. Communications between a pair of UEs 4220 may use a sidelink connection (shown as two separate unidirectional connections 4225). In Figure 42 In the example, sidelink communication occurs between two UEs operating within coverage area 4201. However, sidelink communication may also occur in the following situations: both UEs 4220 are outside coverage area 4201; both UEs 4220 are within coverage area 4201; or one UE 4220 is within coverage area 4201 and the other UE 4220 is outside coverage area 4201. Communication between a pair of UEs and access nodes occurs over unidirectional communication links, where the communication link between the UE and the access node is called an uplink 4230, and the communication link between the access node and the UE is called a downlink 4235.

[0356] Generally, an access node may also be referred to as NodeB, evolved NodeB (eNB), next generation (NG) NodeB (gNB), master eNB (MeNB), secondary eNB (SeNB), master gNB (MgNB), secondary gNB (SgNB), network controller, control node, base station, access point, transmission point (TP), transmission-reception point (TRP), cell, carrier, macro cell, femto cell, pico cell, etc., and UE may also generally be referred to as mobile station, mobile phone, terminal, user, subscriber, site, etc. The access node may provide wireless access according to one or more wireless communication protocols, such as 3GPP Long Term Evolution (LTE), LTE-Advanced (LTE-A), 5G, 5G LTE, 5G NR, sixth generation (6G), high speed packet access (HSPA), IEEE 802.11 series standards, such as 802.11a / b / g / n / ac / ad / ax / ay / be, etc. Although it is understood that the communication system may employ multiple access nodes capable of communicating with multiple UEs, for simplicity, only one access node and two UEs are shown.

[0357] Figure 43 An exemplary communication system 4300 is shown. Generally, the system 4300 enables multiple wireless or wired users to transmit and receive data and other content. The system 4300 can implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), or non-orthogonal multiple access (NOMA).

[0358] In this example, the communication system 4300 includes electronic devices (EDs) 4310a to 4310c, radio access networks (RANs) 4320a and 4320b, a core network 4330, a public switched telephone network (PSTN) 4340, the Internet 4350, and other networks 4360. Figure 43 A certain number of these components or elements are shown, but any number of these components or elements may be included in system 4300.

[0359] EDs 4310a to 4310c are configured to operate or communicate in system 4300. For example, EDs 4310a to 4310c are configured to transmit or receive signals via wireless or wired communication channels. Each ED 4310a to 4310c represents any suitable end-user device and may include (or may be referred to as) a user equipment (UE), a wireless transmitter / receiver unit (WTRU), a mobile station, a fixed or mobile subscriber unit, a cellular phone, a personal digital assistant (PDA), a smartphone, a laptop, a computer, a touchpad, a wireless sensor, or a consumer electronic device. A WTRU may include a transmitter, a receiver, or a combination thereof.

[0360] Here, RAN 4320a includes base station 4370a, and RAN 4320b includes base station 4370b. Each base station 4370a and 4370b is configured to wirelessly connect to one or more of EDs 4310a to 4310c to enable access to core network 4330, PSTN 4340, Internet 4350, or other networks 4360. For example, base stations 4370a and 4370b may include (or may be) one or more of several well-known devices, such as a base transceiver station (BTS), a Node-B (NodeB), an evolved NodeB (eNB), a next generation (NG) NodeB (gNB), a gNB centralized unit (gNB-CU), a gNB distributed unit (gNB-DU), a home NodeB, a home eNodeB, a site controller, an access point (AP), or a wireless router. ED4310a to 4310c are used to connect and communicate with the Internet 4350, and can access the core network 4330, PSTN 4340 or other networks 4360.

[0361] exist Figure 43 In the illustrated embodiment, base station 4370a forms part of RAN 4320a, which may include other base stations, components, or devices. Additionally, base station 4370b forms part of RAN 4320b, which may include other base stations, components, or devices. Each base station 4370a and 4370b is configured to transmit or receive wireless signals within a specific geographic area (sometimes referred to as a "cell"). In some embodiments, multiple-input multiple-output (MIMO) technology may be employed, with each cell having multiple transceivers.

[0362] Base stations 4370a and 4370b communicate with one or more of EDs 4310a through 4310c using wireless communication links over one or more air interfaces 4390. The air interfaces 4390 may utilize any suitable radio access technology.

[0363] It is contemplated that system 4300 may utilize multiple channel access capabilities, including those described above. In specific embodiments, the base station and ED implement 5G New Radio (NR), LTE, LTE-A, or LTE-B. Of course, other multiple access schemes and wireless protocols may also be used.

[0364] RANs 4320a and 4320b communicate with the core network 4330 to provide voice, data, applications, Voice over Internet Protocol (VoIP), or other services to EDs 4310a to 4310c. It should be understood that RANs 4320a and 4320b or the core network 4330 may communicate directly or indirectly with one or more other RANs (not shown). The core network 4330 may also serve as a gateway for other networks, such as the PSTN 4340, the Internet 4350, and other networks 4360. Furthermore, some or all of the EDs 4310a to 4310c may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies or protocols. EDs may communicate with a service provider or switch (not shown) and the Internet 4350 via wired communication channels, rather than (or in addition to) wireless communication.

[0365] although Figure 43 An example of a communication system is shown, but Figure 43 For example, communication system 4300 may include any number of EDs, base stations, networks, or other components in any suitable configuration.

[0366] Figure 44A and Figure 44B An exemplary device that can implement the methods and teachings provided by the present invention is shown. Specifically, Figure 44A An exemplary ED4410 is shown, Figure 44B Shown is an exemplary base station 4470. These components may be used in system 4300 or any other suitable system.

[0367] like Figure 44A As shown, ED 4410 includes at least one processing unit 4400. Processing unit 4400 implements various processing operations of ED 4410. For example, processing unit 4400 can perform signal encoding, data processing, power control, input / output processing, or any other function that enables ED 4410 to operate in system 4300. Processing unit 4400 also supports the methods and instructions described in detail above. Each processing unit 4400 includes any suitable processing or computing device for performing one or more operations. For example, each processing unit 4400 may include a microprocessor, a microcontroller, a digital signal processor, a field programmable gate array, or an application-specific integrated circuit.

[0368] ED4410 also includes at least one transceiver 4402. Transceiver 4402 is used to modulate data or other content for transmission by at least one antenna or network interface controller (NIC) 4404. Transceiver 4402 is also used to demodulate data or other content received by at least one antenna 4404. Each transceiver 4402 includes any suitable structure for generating signals for wireless or wired transmission or for processing signals received wirelessly or via a wire. Each antenna 4404 includes any suitable structure for sending or receiving wireless or wired signals. One or more transceivers 4402 can be used in ED4410, and one or more antennas 4404 can be used in ED4410. Although transceiver 4402 is shown as a single functional unit, it can also be implemented using at least one transmitter and at least one separate receiver.

[0369] ED 4410 also includes one or more input / output devices 4406 or interfaces (e.g., a wired interface to the Internet 4350). Input / output devices 4406 facilitate interaction with users or other devices on a network (network communications). Each input / output device 4406 includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen, including network interface communications.

[0370] In addition, ED 4410 includes at least one memory 4408. Memory 4408 stores instructions and data used, generated, or collected by ED 4410. For example, memory 4408 may store software or firmware instructions executed by one or more processing units 4400, as well as data used to reduce or eliminate interference in incoming signals. Each memory 4408 includes any suitable one or more volatile or non-volatile storage and retrieval devices. Any suitable type of memory may be used, such as random access memory (RAM), read-only memory (ROM), a hard disk, an optical disk, a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, etc.

[0371] like Figure 44BAs shown, base station 4470 includes at least one processing unit 4450, at least one transceiver 4452 (which includes the functionality of a transmitter and a receiver), one or more antennas 4456, at least one memory 4458, and one or more input / output devices or interfaces 4466. A scheduler, as understood by those skilled in the art, is coupled to processing unit 4450. The scheduler may be included within base station 4470 or operate independently of base station 4470. Processing unit 4450 implements various processing operations of base station 4470, such as signal encoding, data processing, power control, input / output processing, or any other functions. Processing unit 4450 may also support the methods and instructions detailed above. Each processing unit 4450 includes any suitable processing or computing device for performing one or more operations. For example, each processing unit 4450 may include a microprocessor, a microcontroller, a digital signal processor, a field programmable gate array, or an application-specific integrated circuit.

[0372] Each transceiver 4452 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each transceiver 4452 also includes any suitable structure for processing signals received wirelessly or wired from one or more EDs or other devices. Although the transmitter and receiver are shown combined as a transceiver 4452, they can be separate components. Each antenna 4456 includes any suitable structure for transmitting or receiving wireless or wired signals. Although a shared antenna 4456 is shown here as coupled to the transceiver 4452, one or more antennas 4456 can be coupled to one or more transceivers 4452, thereby supporting the coupling of separate antennas 4456 to the transmitter and receiver (when the transmitter and receiver are separate components). Each memory 4458 includes any suitable one or more volatile or non-volatile storage and retrieval devices. Each input / output device 4466 facilitates interaction with users or other devices in the network (network communication). Each input / output device 4466 includes any suitable structure for providing information to a user or receiving / providing information from a user, including network interface communication.

[0373] Figure 4545 is a block diagram of a computing system 4500 that can be used to implement the devices and methods disclosed herein. For example, the computing system can be any entity of a UE, an access network (AN), a mobility management (MM), a session management (SM), a user plane gateway (UPGW), or an access stratum (AS). A particular device may utilize all or only a subset of the components shown, and the degree of integration between devices may vary. In addition, a device may include multiple instances of a component, such as multiple processing units, processors, memories, transmitters, receivers, etc. The computing system 4500 includes a processing unit 4502. The processing unit includes a central processing unit (CPU) 4514, a memory 4508, and may also include a mass storage device 4504 connected to a bus 4520, a video adapter 4510, and an I / O interface 4512.

[0374] Bus 4520 can be one or more of any type of bus architecture, including a storage bus or storage controller, a peripheral bus, or a video bus. CPU 4514 can include any type of electronic data processor. Memory 4508 can include any type of non-transient system memory, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or a combination thereof. In one embodiment, memory 4508 can include a ROM for use during startup and a DRAM for storing programs and data, which is used when executing programs.

[0375] The mass storage 4504 may include any type of non-transitory storage device for storing data, programs, and other information and making the data, programs, and other information accessible via the bus 4520. The mass storage 4504 may include one or more of a solid-state drive, a hard disk drive, a magnetic disk drive, or an optical disk drive.

[0376] Video adapter 4510 and I / O interface 4512 provide interfaces for coupling external input and output devices to processing unit 4502. As shown, examples of input and output devices include a display 4518 coupled to video adapter 4510 and a mouse, keyboard, or printer 4516 coupled to I / O interface 4512. Other devices can be coupled to processing unit 4502, and more or fewer interface cards can be used. For example, a serial interface such as a universal serial bus (USB) (not shown) can be used to provide an interface for external devices.

[0377] Processing unit 4502 also includes one or more network interfaces 4506, which may include wired links, such as Ethernet cables, to access nodes or different networks, or wireless links. Network interfaces 4506 enable processing unit 4502 to communicate with remote units over a network. For example, network interface 4506 may provide wireless communication via one or more transmitters / transmit antennas and one or more receivers / receive antennas. In one embodiment, processing unit 4502 is coupled to a local area network 4522 or a wide area network for data processing and communication with remote devices (e.g., other processing units, the Internet, or remote storage facilities).

[0378] It should be understood that one or more steps of the embodiment method provided herein can be performed by corresponding units or modules. For example, a signal can be sent by a sending unit or a sending module. A signal can be received by a receiving unit or a receiving module. A signal can be processed by a processing unit or a processing module. Other steps can be performed by an execution unit or a module, a generation unit or a module, an acquisition unit or a module, a setting unit or a module, an adjustment unit or a module, an increase unit or a module, a reduction unit or a module, a determination unit or a module, a modification unit or a module, a reduction unit or a module, a removal unit or a module, or a selection unit or a module. The corresponding unit or module can be hardware, software, or a combination thereof. For example, one or more of these units or modules can be an integrated circuit, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC).

[0379] Although described in detail, it should be understood that various changes, substitutions, and alterations may be made without departing from the spirit and scope of the present disclosure as defined by the appended claims. Moreover, the scope of the present invention is not limited to the particular embodiments described herein, and as will be readily apparent from this disclosure, processes, machines, manufactures, compositions of matter, components, methods, or steps (now existing or later developed) may perform substantially the same functions or substantially the same functions as the corresponding embodiments described herein. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufactures, compositions of matter, components, methods, or steps.

Claims

1. A method implemented in a wireless device, characterized in that: The method comprises: receiving a low power wake-up signal (LP-WUS) configuration from a network-side device, the LP-WUS configuration indicating a set of frequency resources allocated for LP-WUS transmission; determining, based on the LP-WUS configuration, one or more subsets of the set of frequency resources to be allocated to one or more bits associated with the LP-WUS transmission; determining a first reference signal and a second reference signal according to the LP-WUS configuration; receiving one or more signals from the network-side device on the frequency resource set; determining one or more signal levels based on the one or more signals; The one or more bits are determined based on the one or more signal levels, the first reference signal, and the second reference signal.

2. The method according to claim 1, characterized in that The determining the one or more bits according to the one or more signal levels, the first reference signal, and the second reference signal comprises: Relative differences of the one or more signal levels relative to the first reference signal and relative to the second reference signal are determined.

3. The method according to claim 1 or 2, characterized in that The first reference signal includes a first intensity representing a bit "0", the second reference signal includes a second intensity representing a bit "1", and determining the one or more bits based on the one or more signal levels, the first reference signal, and the second reference signal includes: When a difference between a first signal level of the one or more signal levels and the first reference signal is less than a difference between the first signal level of the one or more signal levels and the second reference signal, a first bit of the one or more bits is decoded as "1".

4. The method according to any one of claims 1 to 3, characterized in that The first reference signal includes a first intensity representing a bit "0", the second reference signal includes a second intensity representing a bit "1", and determining the one or more bits based on the one or more signal levels, the first reference signal, and the second reference signal includes: When a difference between a first signal level of the one or more signal levels and the first reference signal is greater than a difference between the first signal level of the one or more signal levels and the second reference signal, a first bit of the one or more bits is decoded as '0'.

5. The method according to any one of claims 1 to 4, characterized in that Also includes: The one or more signals are passed through an envelope detector before determining one or more signal levels based on the one or more signals.

6. The method according to any one of claims 1 to 5, characterized in that Also includes: The one or more signals are decoded based on on-off keying (OOK) modulation.

7. The method according to any one of claims 1 to 6, characterized in that The LP-WUS configuration is received in a higher layer signal.

8. The method according to any one of claims 1 to 7, characterized in that The LP-WUS configuration further indicates at least one of the following: The number of bits multiplexed in an Orthogonal Frequency Division Multiplexing (OFDM) symbol, The number of LP-WUS multiplexed in the frequency domain, a first subset of frequency resources allocated for a zero reference signal, or A second subset of frequency resources is allocated for a consistent reference signal.

9. The method according to any one of claims 1 to 8, characterized in that The first reference signal includes a first intensity, and the first intensity includes an estimated noise level intensity.

10. The method according to any one of claims 1 to 9, characterized in that The second reference signal includes a second strength, and the second strength includes estimated interference power and channel fading level strength.

11. The method according to any one of claims 1 to 9, characterized in that The determining the first reference signal and the second reference signal according to the LP-WUS configuration further includes: At least one of the first reference signal or the second reference signal is received from the network device.

12. A method implemented in a wireless transmit / receive unit (WTRU), characterized in that: The method comprises: receiving a low power wake-up signal (LP-WUS) configuration indicating a set of frequency resources allocated for LP-WUS transmission; determining one or more subsets of the set of frequency resources to be allocated to one or more bits associated with the LP-WUS transmission; determining a first strength based on a first signal received on a first subset of frequency resources; determining a second strength based on a second signal received on a second subset of frequency resources; determining one or more signal levels based on one or more signals received on the one or more subsets of the set of frequency resources; The one or more bits are detected based on the first strength, the second strength, and the one or more signal levels.

13. The method according to claim 12, characterized in that The LP-WUS configuration is received in a higher layer signal.

14. The method according to claim 12 or 13, characterized in that The LP-WUS configuration further indicates at least one of the following: The number of bits multiplexed in an Orthogonal Frequency Division Multiplexing (OFDM) symbol; The number of LP-WUS multiplexed in the frequency domain; a first subset of frequency resources allocated for a zero reference signal; or A second subset of frequency resources is allocated for a consistent reference signal.

15. The method according to any one of claims 12 to 14, characterized in that The first intensity comprises an estimated noise level intensity.

16. The method according to any one of claims 12 to 15, characterized in that The second strength includes estimated interference power and channel fading level strength.

17. A device, characterized in that include: at least one processor; A non-transitory memory storing programming instructions that, when executed by the at least one processor, cause the system to perform the method of any one of claims 1 to 16.

18. A non-transitory computer-readable storage medium, characterized in that The method comprises instructions which, when executed by a processor, cause the processor to perform the method according to any one of claims 1 to 16.

19. A wireless transmit / receive unit (WTRU), characterized in that include: at least one processor; A non-transitory computer-readable storage medium storing a program comprising instructions that, when executed by the at least one processor, cause the WTRU to perform the method according to any one of claims 1 to 16.

20. A non-transitory computer-readable storage medium, characterized in that The method comprises instructions which, when executed by a processor, cause the processor to perform the method according to any one of claims 1 to 16.

21. A method for wireless communication implemented in a wireless transmit / receive unit (WTRU), characterized in that: The method comprises: receiving a low power wake-up signaling (LP-WUS) configuration, the LP-WUS configuration indicating a first type of signaling, a second type of signaling, and a reference signal configuration, wherein the WTRU includes a first power state and a second power state; determining a received signal strength based on the reference signal configuration; operating the receiver in the first power state and monitoring for signals according to the first type of signaling based on a first condition on the received signal strength; Based on a second condition on the received signal strength, the receiver is operated in the second power state and monitors the signal according to the second type of signaling.

22. The method according to claim 21, characterized in that The reference signal configuration also indicates the configured signal strength.

23. The method according to claim 21 or 22, characterized in that The first condition is that the received signal strength is higher than the configured signal strength.

24. The method according to claim 22 or 23, characterized in that The second condition is that the received signal strength is lower than the configured signal strength.

25. The method according to any one of claims 21 to 24, characterized in that The LP-WUS configuration also indicates the post-envelope detection (ED) center frequency and the post-ED bandwidth.

26. The method according to any one of claims 21 to 25, characterized in that The first power state is lower than the second power state.

27. The method according to claim 26, characterized in that The monitoring of the signal according to the first type of signaling is based on the post-ED center frequency and the post-ED bandwidth.

28. The method according to any one of claims 21 to 27, characterized in that The LP-WUS configuration also indicates one or more front ED center frequencies and one or more front ED bandwidths.

29. The method according to claim 28, characterized in that The monitoring of the signal according to the second type of signaling is based on the one or more former ED center frequencies and the one or more former ED bandwidths.

30. The method according to any one of claims 21 to 29, characterized in that In the first power state a radio frequency (RF) EDLP-WUR is used.

31. The method according to any one of claims 21 to 30, characterized in that In the second power state an intermediate frequency (IF) / baseband (BB) EDLP-WUR is used.

32. The method according to any one of claims 21 to 31, characterized in that The LP-WUS configuration indicates support for at least one of a post-ED signaling design, a pre-ED signal, a post-ED signal, an LP-WUS transmission data rate, or an LP-WUS coding scheme and coding rate.

33. The method according to any one of claims 21 to 32, characterized in that The first condition is to support post-ED signaling design.

34. The method according to claims 21 to 33, characterized in that The second condition is that the post-ED signaling design is not supported.

35. A wireless transmit / receive unit (WTRU), characterized in that include: at least one processor; A non-transitory computer-readable storage medium storing a program comprising instructions that, when executed by the at least one processor, cause the WTRU to perform the method according to any one of claims 21 to 34.

36. A non-transitory computer-readable storage medium, characterized in that comprising instructions which, when executed by a processor, cause the processor to perform the method according to any one of claims 21 to 34.

37. A method, characterized in that include: The base station transmits a low power wake-up signal (LP-WUS), which generates a signal of at least a specific intermediate frequency / center frequency (IF) after / after envelope detection (ED) for wake-up signal (WUS) message demodulation and detection in a receiver.

38. The method according to claim 37, wherein The LP-WUS sent by the base station includes at least two sets of continuous frequency resources separated by the IF.

39. The method according to claim 37 or 38, characterized in that The LP-WUS signal sent by the base station includes at least one continuous frequency resource, and background traffic signals at each frequency are separated from the continuous frequency resource by the specific IF.

40. A method implemented in a base station, characterized in that: The method comprises: determining a low power wake-up signal (LP-WUS) configuration for a wireless device, wherein the LP-WUS configuration comprises one or more subsets of a set of frequency resources to be allocated to one or more bits associated with the LP-WUS; sending the LP-WUS configuration to the wireless device, the LP-WUS configuration indicating a set of frequency resources allocated for LP-WUS transmission; One or more signals are sent to the wireless device on the set of frequency resources.

41. The method according to claim 40, wherein The one or more signals are encoded based on On-Off Keying (OOK) modulation.

42. The method according to claim 40 or 41, characterized in that The LP-WUS configuration is received in a higher layer signal.

43. The method according to any one of claims 40 to 42, characterized in that The LP-WUS configuration further indicates at least one of the following: The number of bits multiplexed in an Orthogonal Frequency Division Multiplexing (OFDM) symbol, or The number of LP-WUS multiplexed in the frequency domain.

44. The method according to any one of claims 40 to 43, characterized in that The LP-WUS configuration also indicates a first subset of frequency resources allocated for a zero reference signal.

45. The method according to any one of claims 40 to 44, characterized in that The LP-WUS configuration further indicates a second subset of frequency resources allocated for a consistent reference signal.

46. ​​The method according to any one of claims 40 to 45, characterized in that Also includes: The one or more signal levels are determined based on one or more bits, a first reference signal, and a second reference signal, wherein bits having a first bit value are encoded based on the first reference signal and bits having a second bit value are encoded based on the second reference signal.

47. The method according to any one of claims 40 to 46, characterized in that The first reference signal includes a first strength indicating a bit "0", the second reference signal includes a second strength indicating a bit "1", and determining the one or more signals based on the one or more bits, the first reference signal, and the second reference signal includes: When a first bit among the one or more bits is "1", encoding a first signal among the one or more signals to have a strength equal to that of the first reference signal; or When the first bit among the one or more bits is “0”, the first signal among the one or more signals is encoded to have a strength equal to that of the second reference signal.

48. The method according to any one of claims 40 to 47, characterized in that Also includes: At least one of a first reference signal or a second reference signal is sent to the wireless device.

49. A base station, characterized in that include: at least one processor; A non-transitory computer-readable storage medium storing a program, the program comprising instructions which, when executed by the at least one processor, cause the base station to perform the method according to any one of claims 37 to 48.

50. A non-transitory computer-readable storage medium, characterized in that comprising instructions which, when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 37 to 44.

Images