A fast wake-up method and device suitable for low-power communication

Abstract

The application discloses a kind of quick wake-up method and device suitable for low-power communication, the method uses the wake-up signal that independently occupies one or more sub-band all downlink time slots in low-power communication, set frequency domain bandwidth less than single sub-band bandwidth, adopt ZC sequence or small m sequence as wake-up sequence, and allocate the wake-up group with multiple wake-up signals to UE, in the UE wake-up period, if detecting wake-up signal is any wake-up signal contained in wake-up group, then the UE enters working state from dormant state.The application designs a kind of wake-up signal based on 230MHz frequency band's internet of things application, the wake-up signal independently occupies one or more sub-band all downlink time slots, adopts long sequence with good autocorrelation performance to obtain better performance, using the autocorrelation characteristics of the sequence cyclic shift, the cross-correlation characteristics of different root indexes of ZC sequence, solve the problem of time-frequency domain shared by multiple users.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a fast wake-up method and apparatus suitable for low-power communication. Background Technology

[0002] The 230MHz band is characterized by its large available bandwidth and discontinuous frequency band. In low-power IoT applications based on the 230MHz band, wireless communication terminals (UEs) are typically powered by batteries or their own harvested energy (e.g., solar power). Furthermore, in applications with small amounts of data and infrequent data exchange, most of the terminal device's power consumption is spent on listening rather than data transmission and reception. To conserve energy, UEs are usually in a sleep state, periodically waking up by searching for a wake-up signal within a wake-up window. Once a wake-up signal is found, the UE switches to working mode to transmit and receive data. Low-power IoT applications typically involve massive connections, with a single base station needing to handle the wake-up of hundreds of thousands of UEs.

[0003] The patent document with patent number CN201611201027.2 discloses a method for on-demand fast wake-up of wireless sensor networks based on constructive interference. Among any adjacent data transmission routing nodes, the node will establish a multi-hop wake-up route with minimum hop count between any node in need and its forwarding node according to the gradient, and specify constructive interference cooperative nodes and wake-up signal forwarding delay for the nodes on the wake-up route. When there is a wake-up requirement during data communication, the wake-up will be performed along the wake-up route. At the same time, by setting the forwarding delay of the wake-up signal, the routing nodes and cooperative nodes on the wake-up route forward the wake-up signal simultaneously, and the wake-up range is extended by constructive interference until the main antenna of the target receiving node is woken up.

[0004] The aforementioned patents rapidly wake up sleeping nodes when needed, thereby improving the real-time performance of data transmission while maximizing energy efficiency. However, in traditional communication signals (such as LTE / NR signals), due to the use of channel coding methods such as OFDM modulation, turbo code encoding / low-density parity-check code / polar code at the transmitting end, the receiving end must perform complex signal processing operations such as discrete Fourier transform and forward error correction decoding. While wake-up signals transmitted using these methods can wake up more independent users and increase the transmission rate, they are not suitable for applications in low signal-to-noise ratio environments. Furthermore, the receiving end algorithm is complex, and receiving this signal also consumes a lot of energy, making it unsuitable for low-power scenarios. Therefore, this paper proposes a fast wake-up method and device suitable for low-power communication. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a fast wake-up method applicable to low-power communication. In low-power communication, the method uses a wake-up signal that independently occupies all downlink time slots of one or more sub-bands. The frequency domain bandwidth is set to be less than the bandwidth of a single sub-band. A ZC sequence or a small m sequence is used as the wake-up sequence to allocate wake-up groups containing multiple wake-up signals to the UE. During the UE's wake-up cycle, if any wake-up signal contained within the wake-up group is detected, the UE transitions from a sleep state to a working state.

[0006] Furthermore, in the method, the UE is usually in a sleep state, and it periodically wakes up to search for a wake-up signal in the wake-up window. Once a wake-up signal is found, it switches to working mode to send and receive data.

[0007] Furthermore, when the method uses the ZC sequence, the ZC sequence generates several base sequences with different u values ​​but the same length by providing u values ​​that are coprime to the sequence length. The base station configures different cyclic shift intervals according to the radius supported by the cell, and sets each sequence with different u values ​​or different cyclic shifts as a wake-up sequence.

[0008] Furthermore, when the method uses ZC sequences, a subband supports multiple wake-up sequences.

[0009] Furthermore, the base station configures different cyclic shift intervals based on the radius supported by the cell. Each sequence with a different u value or a different cyclic shift is a unique wake-up sequence, and a sub-band supports multiple wake-up sequences.

[0010] Furthermore, the method employs long sequences with good autocorrelation performance (such as ZC sequences, small m sequences, etc.) to achieve better performance.

[0011] Furthermore, in the method, M radio frames are set as one wake-up cycle in the time domain, and each wake-up cycle is divided into N wake-up time domain groups. Each wake-up group consists of M / N radio frames, where M and N are both positive integers.

[0012] Furthermore, in the method, the wake-up signal is repeatedly sent within each wake-up group, with the number of repetitions Nrep = M / N.

[0013] Furthermore, in the method, each UE is assigned a wake-up group number and detects the wake-up signal within its own wake-up cycle, while remaining in a sleep state at other times.

[0014] Furthermore, the method utilizes the autocorrelation characteristics of cyclic shifting of the sequence and the cross-correlation characteristics of different root indices of the ZC sequence to address the problem of multiple users sharing the time-frequency domain.

[0015] Furthermore, in the method, each UE is assigned a wake-up group number, and the UE detects the wake-up signal during its own wake-up group time, and remains in sleep mode at other times.

[0016] Furthermore, in the method, there are multiple wake-up signals with different u values ​​and cyclic shift values ​​v within the wake-up group, including global wake-up, sequence group wake-up, and individual wake-up signals.

[0017] Furthermore, in the method, a reserved unique sequence is used as the global wake-up signal, and the base station assigns a unique sequence to the UE as its group / individual wake-up signal. UEs within the sequence group share the same unique sequence, while other UEs have independent wake-up sequences.

[0018] Furthermore, in the method, the base station assigns different wake-up subbands to different UEs, or wake-up groups with different time domains within the same wake-up subband, or different sequences within the same wake-up group in the same time domain of the same subband.

[0019] Furthermore, in the method, different sequences include different u values ​​or different cyclic shifts v.

[0020] On another level, the present invention provides a fast wake-up device suitable for low-power communication, including...

[0021] The sending module is used to send a UE wake-up message on the wake-up channel. The UE wake-up message contains target address information indicating the UE to be woken up.

[0022] The receiving module is used to listen to the data channel and receive data upload messages from the UE;

[0023] The feedback module is used to send a data upload confirmation message to the UE that sent the data upload message on the confirmation channel after successfully receiving the data upload message sent by a UE.

[0024] The beneficial effects of this invention are as follows:

[0025] This invention designs a wake-up signal for IoT applications in the 230MHz band. This wake-up signal independently occupies all downlink time slots in one or more sub-bands. It employs a long sequence with good autocorrelation performance (e.g., ZC sequence, small m sequence) to achieve superior performance. By utilizing the autocorrelation characteristics of the cyclic shift of this sequence and the cross-correlation characteristics of different root indices of the ZC sequence, the problem of multiple users sharing the time-frequency domain is solved. Furthermore, this wake-up signal can be multiplexed by multiple users and is easy for the receiver to receive, demonstrating strong market application prospects. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 Wake-up cycle and wake-up diagram provided for embodiments of this application;

[0028] Figure 2 This is a wireless frame structure diagram provided for an embodiment of this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. “Multiple” generally includes at least two, but does not exclude the inclusion of at least one.

[0031] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0032] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes said element.

[0033] Example 1

[0034] This embodiment provides a fast wake-up method applicable to low-power communication. In low-power communication, the method uses a wake-up signal that independently occupies all downlink time slots of one or more sub-bands, sets the frequency domain bandwidth to be less than the single sub-band bandwidth, and uses ZC sequence or small m sequence as the wake-up sequence to allocate a wake-up group with multiple wake-up signals to the UE. During the UE wake-up period, if the wake-up signal is detected to be any of the wake-up signals contained in the wake-up group, the UE enters the working state from the sleep state.

[0035] In this embodiment, the UE is usually in a sleep state. It periodically wakes up and searches for a wake-up signal in the wake-up window. Once a wake-up signal is found, it switches to working mode to send and receive data.

[0036] In this embodiment, the wake-up signal occupies the entire downlink time domain of the wireless frame, and the frequency domain bandwidth is less than the single subband bandwidth. It adopts ZC sequence or little m sequence. The ZC sequence also generates several base sequences with different u values ​​and the same length by providing u values ​​that are coprime to the sequence length.

[0037] In this embodiment, the base station configures different cyclic shift intervals according to the radius supported by the cell. Each sequence with a different u value or a different cyclic shift is a unique wake-up sequence, and one subband supports multiple wake-up sequences.

[0038] This embodiment is applied in a 230MHz low-power communication system, using an independent sub-band for sending wake-up signals.

[0039] In this embodiment, the uplink and downlink channel quality of the working subband occupied by the wake-up signal are obtained by fitting the modulation and coding levels of the uplink and downlink directions, respectively. The uplink and downlink channel quality are then compared with preset values ​​to classify the current working subband into the candidate subband set or the poor subband set. When there is a service that needs to be transmitted, the working subband is selected from the candidate subband set for transmission.

[0040] The wake-up signal in this embodiment can be multiplexed by multiple users and is easy for the receiving end to receive, thus having a strong market application prospect.

[0041] Example 2

[0042] In practical applications, this embodiment provides a wake-up cycle and wake-up group, such as... Figure 1 As shown, in the time domain, this embodiment uses M radio frames as one wake-up cycle, and each wake-up cycle is divided into N wake-up time domain groups. Each wake-up group consists of M / N radio frames, and the wake-up signal within the group is repeatedly transmitted, with the number of repetitions Nrep = M / N. Where M and N are both positive integers.

[0043] In this embodiment, each UE is assigned a wake-up group number. The UE detects the wake-up signal during its own wake-up group time and remains in sleep mode at other times.

[0044] In this embodiment, each wake-up group contains multiple wake-up signals with different u values ​​and cyclic shift values ​​v, which are divided into global wake-up, sequence group wake-up, and individual wake-up signals.

[0045] In this embodiment, a unique sequence is reserved as the global wake-up signal. The base station assigns a unique sequence to each UE as its group / individual wake-up signal. UEs within the sequence group share the same unique sequence, while other UEs have their own independent wake-up sequences.

[0046] In this embodiment, once the UE detects a global wake-up signal, a wake-up signal of its own group, or a wake-up signal of its own, it will enter the working state from the sleep state.

[0047] In this embodiment, the base station assigns different wake-up subbands to different UEs, or wake-up groups with different time domains within the same wake-up subband, or different sequences within the same time domain wake-up group of the same subband.

[0048] Example 3

[0049] In practical applications, this embodiment takes a 230MHz low-power communication system where each subband occupies a bandwidth of 25kHz as an example, and the wireless frame structure is as follows: Figure 2 As shown, the time domain values ​​are taken in Ts as the basic unit, Ts = 1 / (2000×64)s, and the length of each radio frame is 3200Ts, or 25ms.

[0050] In this embodiment, a wireless frame consists of 5 subframes with a length of 5ms each. Each subframe is 640Ts. Subframe 0 is a downlink subframe, and subframes 2, 3, and 4 are uplink subframes.

[0051] In this embodiment, subframe 1 is a special subframe, comprising three fields: DwPTS, GP, and UpPTS. The special subframe configuration is shown in Table 1. A maximum of 925 Ts can be used for downlink within a single radio frame.

[0052] Table 1 Special Subframe Configurations (DwPTS / UpPTS Length)

[0053] Special subframe configuration DwPTS UpPTS 0 <![CDATA[285·T s ]]> <![CDATA[284·T s ]]>

[0054] Example 4

[0055] In practical applications, this embodiment takes the wake-up signal occupying two independent sub-bands as an example, and the time-frequency structure is as follows:

[0056] In this embodiment, the physical layer wake-up signal is composed of the cyclic prefix T. CP and sequence T SEQ Composition, TSEQ =34Ts,T SEQ =919Ts, occupying all downlink symbols of one radio frame (subframe 1 and DwPTS), with 34Ts at the GP tail. Two consecutive radio frames constitute one wake-up group. Within a wake-up group, the wake-up signal of the two radio frames is repeatedly transmitted. The wake-up signal adopts the ZC sequence, and the generated ZC sequence is shown in Equation (1). The frequency domain signal is shown in Equation (2), with zeros padded to N. SEQ Point, see equation (3).

[0057] In this embodiment, the basic sequence of the wake-up signal is obtained by IDFT and cyclic shifting as follows:

[0058] s u (n)=circshift(ifft(X(k)),N cp ) / (N ZC / N SEQ )

[0059] The time-domain cyclic shift signal in this embodiment is shown in equation (4); the addition of CP is shown in equation (5);

[0060]

[0061] In the formula: u is the root parameter, configured by the base station for the user, with a value range of 1 to 138; N ZC N is the length of the Zadoff-Chu sequence. ZC =139.

[0062]

[0063] X = [X] u ((N zc -1) / 2),…,X u (N zc -1),0,0,…,0,X u (0),X u (1),…X u ((N zc -1) / 2-1)] (3)

[0064] S u,v (n)=S u ((nN CS ·v)modN SEQ (4)

[0065] In the formula: v is the cyclic shift index, which is configured by the base station to the user and ranges from 0 to 34: N CS N is the time-domain cyclic shift value. CS =26; the range of n is 0≤n≤N SEQ N SEQThe range is N SEQ =919.

[0066] S u，v (n)=[S u，v S u，v (0:N) CP -1)] (5)

[0067] In the formula: the range of n is 0 ≤ n ≤ N SEQ +N CP -1; N CP It is 34.

[0068] This embodiment starts from n f Starting with a radio frame where mod2 = 0, if a user needs to be woken up, the base station uses the user's u and v values ​​to send a wake-up signal in that user's transmission group, repeating this twice, once per radio frame.

[0069] The time-domain baseband signal in this embodiment is shown in equation (6).

[0070]

[0071] In the formula: the range of t is 0 ≤ t ≤ T SEQ +T CP -1; T SEQ =919T s ;T CP =34T s ;Δf wake Subcarrier spacing 139.3 Hz; β wake Wake-up signal amplitude scaling factor; Resource mapping offset,

[0072] From the above, we can see that the wake-up cycle of this embodiment is 2s, with a total of 80 radio frames. Each wake-up group occupies 2 radio frames, and the time domain length is 50ms. There are 40 wake-up groups in one cycle, and each UE works for 50ms within 2s.

[0073] In this embodiment, the wake-up signal occupies a total bandwidth of 139.3Hz * 139 = 19.4kHz, which is less than the subband bandwidth of 25kHz. Each wake-up group supports a maximum of 138 u values ​​and 35 available cyclic shift positions, for a total of 138 * 35 = 4830 sequences. The sequence with u = 1 and cyclic shift v = 0 by default is the global wake-up sequence.

[0074] In this embodiment, each wake-up group can support 4830-1 independent users, and each wake-up subband can support 193160 independent users per wake-up cycle.

[0075] Example 5

[0076] This embodiment provides a fast wake-up device suitable for low-power communication, including...

[0077] The sending module is used to send a UE wake-up message on the wake-up channel. The UE wake-up message contains target address information indicating the UE to be woken up.

[0078] The receiving module is used to listen to the data channel and receive data upload messages from the UE;

[0079] The feedback module is used to send a data upload confirmation message to the UE that sent the data upload message on the confirmation channel after successfully receiving the data upload message sent by a UE.

[0080] In summary, this invention designs a wake-up signal for IoT applications in the 230MHz band. This wake-up signal independently occupies all downlink time slots of one or more sub-bands, employs a long sequence with good autocorrelation performance (such as ZC sequences, small m sequences, etc.) to achieve better performance, and utilizes the autocorrelation characteristics of the cyclic shift of the sequence and the cross-correlation characteristics of different root indices of the ZC sequence to solve the problem of multiple users sharing the time-frequency domain. Furthermore, this wake-up signal can be multiplexed by multiple users and is easy for the receiver to receive, demonstrating strong market application prospects.

[0081] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0082] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of a necessary general-purpose hardware platform, or by a combination of hardware and software. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a computer product. The present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0083] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable resource update device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable resource update device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0084] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable resource update device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0085] These computer program instructions may also be loaded onto a computer or other programmable resource update device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable device for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0086] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0087] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0088] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fast wake-up method for low power consumption communication, characterized in that, The method uses a wake-up signal independently occupying one or more sub-bands of all downlink time slots in low-power communication, sets a frequency domain bandwidth less than a single sub-band bandwidth, uses a ZC sequence as a wake-up sequence to allocate a wake-up group with multiple wake-up signals to a UE, and in a UE wake-up period, if a wake-up signal is detected as any wake-up signal contained in the wake-up group, the UE enters a working state from a sleep state, wherein When the method uses a ZC sequence, the ZC sequence generates several base sequences with different u values and the same length by providing a u value coprime with the sequence length, the base station configures different cyclic shift intervals according to the radius size supported by the cell, and sets each sequence with different u values or cyclic shifts as a wake-up sequence, characterized in that When the method uses a ZC sequence, one sub-band supports multiple wake-up sequences, characterized in that In the method, M radio frames are set as a wake-up period in the time domain, each wake-up period is divided into N wake-up time domain groups, and each wake-up group is composed of M / N radio frames, wherein M and N are positive integers.

2. The method of claim 1, wherein the low-power communication is Bluetooth Low Energy (BLE) communication. In the method, the wake-up signal in each wake-up group is repeatedly sent, and the repetition number Nrep=M / N.

3. The method of claim 1, wherein the low-power communication is Bluetooth Low Energy (BLE) communication. In the method, each UE is allocated a wake-up group number and detects a wake-up signal in its own wake-up period, and is in a sleep state at other times.

4. The method of claim 1, wherein the low-power communication is Bluetooth Low Energy (BLE). In the method, there are multiple wake-up signals with different u values and cyclic shift values v in the wake-up group, and the wake-up signals include global wake-up, sequence group wake-up, and individual wake-up signals.

5. The method of claim 4, wherein, In the method, a reserved unique sequence is used as a global wake-up signal, the base station specifies a unique sequence for the UE as its group / individual wake-up signal, the UEs in the sequence group share the same unique sequence, and other UEs have independent wake-up sequences.

6. The method for fast wake-up with low power consumption communication according to claim 1, wherein, In the method, the base station specifies different wake-up sub-bands for different UEs, or different wake-up groups in the same wake-up sub-band time domain, or different sequences in the same sub-band and the same time domain wake-up group.

7. The method of claim 6, wherein the low-power communication is Bluetooth Low Energy (BLE) communication. In the method, sequence difference includes u value or cyclic shift v difference.

8. A fast wake-up device for low-power communication, used to execute the fast wake-up method for low-power communication according to any one of claims 1 to 7.

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