Method and device for controlling lead code duration of physical layer protocol data unit
By extending the preamble length of the PPDU, the underload problem when the wireless communication module wakes up from a low-power state is solved, power consumption is reduced, transmission efficiency is improved, and the use of virtual delimiters is reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-17
- Publication Date
- 2026-04-14
AI Technical Summary
When the wireless communication module wakes up from a low-power state to a normal state, the wake-up time is long, which causes underload problems in the generation and transmission of PPDU. Virtual delimiters need to be added, which increases power consumption.
By deliberately extending the preamble length of the PPDU, adding redundant information or adjusting the rate using fields such as HE-SIG-B and HE-LTF, the preamble time is prolonged, and the number of virtual delimiters in the data fields is reduced.
It reduces the power consumption of the wireless communication module during the wake-up process, improves transmission efficiency, lowers power consumption, and avoids the need to add virtual delimiters to the data field.
Smart Images
Figure CN121865378A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a wireless communication method in which the preamble length of the PPDU can be intentionally extended when the wireless communication module transitions from a low-power state to a normal state. Background Technology
[0002] To reduce power consumption when the wireless communication module does not need to transmit data packets, the PCIe (Peripheral Component Interconnect Fast Channel) interface enters a low-power state, such as L1.2, to disable some circuitry, such as the phase-locked loop, transmitter, and receiver. Then, when the wireless communication module needs to transmit data packets, the PCIe interface is woken up and returns to a normal state, such as L0, to allow the wireless communication module to acquire data to generate Physical Layer Protocol Data Units (PPDUs) for transmission. However, because the wake-up time from L1.2 to L0 is relatively long, if underload occurs during PPDU generation and transmission, the wireless communication module needs to add a large number of virtual delimiters to the payload, thus reducing efficiency. Furthermore, since wireless communication modules typically use higher bandwidth, higher spatial stream counts (NSS), or higher modulation and coding schemes (MCS), adding extra virtual delimiters to the PPDU payload means that the wireless communication module needs to consume more power to transmit the virtual data. Summary of the Invention
[0003] Therefore, the objective of this invention is to provide a wireless communication method in which the preamble length of the PPDU can be intentionally extended when the wireless communication module transitions from a low-power state to a normal state, in order to solve the aforementioned problem.
[0004] According to an embodiment of the present invention, a control method for a wireless communication module includes the following steps: starting from a low-power state to a normal state; acquiring multiple MPDUs; generating a preamble and extending the length of the preamble by adding unnecessary or redundant information to the preamble, or by adjusting the rate of the preamble; and generating a PPDU using the preamble and multiple MPDUs.
[0005] According to one embodiment of the present invention, the wireless communication module of an electronic device is configured to perform the following steps: starting from a low-power state to a normal state; acquiring multiple MPDUs; generating a preamble and extending the length of the preamble by adding unnecessary or redundant information to the preamble, or by adjusting the rate of the preamble; and generating a PPDU using the preamble and multiple MPDUs.
[0006] These and other objectives of the invention will undoubtedly become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments, which are illustrated in various figures and drawings. Attached Figure Description
[0007] Figure 1 This is a schematic diagram of a wireless communication system according to an embodiment of the present invention.
[0008] Figure 2 This is a flowchart of a control method for a wireless communication module according to an embodiment of the present invention.
[0009] Figure 3 The PPDU structure is shown.
[0010] Figure 4 This is a schematic diagram illustrating the operation of a wireless communication module according to an embodiment of the present invention. Detailed Implementation
[0011] In the following description and claims, certain terms are used to refer to specific system components. As will be understood by those skilled in the art, manufacturers may use different names to refer to a component. This document is not intended to distinguish between components with different names but the same function. In the following discussion and claims, the terms "comprising" and "including" are used in an open-ended manner and should therefore be interpreted as "including, but not limited to...". The term "connection" means a direct or indirect electrical connection. Thus, if a first device is connected to a second device, the connection can be a direct electrical connection or an indirect electrical connection via other devices and connections.
[0012] Figure 1 This is a schematic diagram of a wireless communication system according to an embodiment of the present invention. Figure 1 As shown, the wireless communication system includes an access point (AP) 110 and at least one workstation such as 120. AP 110 is a Wi-Fi access point that allows other wireless devices, such as workstation 120, to connect to a wired network. AP 110 mainly includes a processing circuit 112 and a wireless communication module 114. Workstation 120 is a Wi-Fi workstation, including a processing circuit 122 and a wireless communication module 124. Workstation 120 can be a mobile phone, tablet, laptop, or any other electronic device capable of wirelessly communicating with AP 110. Furthermore, the wireless communication modules 114 / 124 include at least a Media Address Control (MAC) layer circuit and a physical layer circuit.
[0013] In this embodiment, AP 110 and workstation 120 are multi-link devices (MLDs), meaning that AP 110 and workstation 120 communicate using two or more links. In this embodiment, each of the two or more links may use a channel corresponding to a 2.4 GHz band (e.g., 2.412 GHz - 2.484 GHz), a 5 GHz band (e.g., 4.915 GHz - 5.825 GHz), or a 6 GHz band (e.g., 5.925 GHz - 7.125 GHz).
[0014] The wireless communication module 114 can selectively operate in a normal mode or a power-saving mode (sleep mode). In this embodiment, the wireless communication module 114 has PCIe-related circuitry and selectively operates in a normal / active state (e.g., L0 state) or a low-power state (e.g., L1.2 state) as defined in the PCIe specification. Specifically, when the wireless communication module 114 does not need to transmit data packets, it enters a low-power state to disable some circuitry, such as the phase-locked loop, transmitter, and receiver; when it needs to transmit data packets, a wake-up mechanism is triggered, causing the wireless communication module 114 to transition from the low-power state to the normal state to acquire data and generate a PPDU to be transmitted. As described in the background section of this invention, transitioning from the L1.2 state to the L0 state requires a long wake-up time. If an underload problem occurs during PPDU generation and transmission, conventional wireless communication modules need to add a large number of virtual delimiters to the payload, thus requiring higher power consumption to transmit virtual data. Therefore, the following embodiments provide a control method for the wireless communication module 114 to address these conventional problems.
[0015] Figure 2This is a flowchart of a control method for one of the wireless communication modules 114 and 124 according to an embodiment of the present invention. In the following description, the wireless communication module 114 performs the following steps as an example, but the invention is not limited thereto. In step 200, the process begins, one or more links have been established between AP 110 and workstation 120, and AP 110 has just been woken up. For example, AP 110 begins to enter a low-power state from normal mode, at which time the wireless communication module 114 has not yet been fully woken up. In step 202, the wireless communication module 114 acquires multiple MAC Service Data Units (MSDUs), and the wireless communication module 114 aggregates the MSDUs to generate MPDUs, one of which may include one or more MSDUs. In step 204, the wireless communication module 114 performs sequence number (SN) and packet number (PN) assignment for each MPDU. In step 206, encryption is performed on the MPDUs. In step 208, the MAC layer circuitry within the wireless communication module 114 performs preamble duration control to intentionally extend the preamble length of the PPDU generated in the next step. In step 210, the MAC layer circuit within the wireless communication module 114 aggregates multiple MPDUs to generate a PPDU, and transmits the PPDU to the workstation 120 via the physical layer circuit of the wireless communication module 114. It should be noted that steps 202-206 and 210 are known to those skilled in the art; the focus of this invention is on the preamble duration control in step 208, therefore detailed operations of steps 202-206 and 210 are omitted here.
[0016] Regarding the preamble duration control in step 208, the wireless communication module 114 can extend the preamble length of the PPDU by adding some unnecessary or redundant information to the preamble. Figure 3 The diagram shows a High Efficiency (HE) PPDU 300 as defined in IEEE 802.11ax. The HE PPDU includes a conventional preamble, an HE preamble, a data field, and packet extensions (PE). The conventional preamble includes an L-STF field, an L-LTF field, and an L-SIG field. The HE preamble includes an RL-SIG field, an HE-SIG-A field, an optional HE-SIG-B field, an HE-STF field, and multiple HE-LTF fields. In this embodiment, the wireless communication module 114 can extend the length of the preamble by controlling the contents of the HE-SIG-B field and / or the HE-LTF field.
[0017] The HE-SIG-B field contains resource element allocation information for the station communicating with AP 110, and this information can be recorded using a maximum of 16 symbols. To extend the preamble length, the wireless communication module 114 can intentionally control the HE-SIG-B field to have more symbols than required to record all resource element allocation information. In one embodiment, the wireless communication module 114 can intentionally control the HE-SIG-B field to have the maximum allowed number of symbols (i.e., 16 symbols), even if a small number of symbols (i.e., less than 16 symbols) is sufficient to record all resource element allocation information. Furthermore, for these additional symbols that are not needed for recording resource element allocation information, the wireless communication module 114 can pad them with additional symbols.
[0018] In one embodiment, the wireless communication module 114 may set a dual-carrier modulation (DCM) indicator bit in the HE-SIG-A field to indicate that DCM is applied to one or more fields of the preamble, such as the HE-SIG-B field, where DCM can introduce frequency diversity into the OFDM system by transmitting the same information on two frequency-separated subcarriers. The length of the preamble can be extended by adding a DCM indicator bit to indicate DCM application.
[0019] In one embodiment, the wireless communication module 114 may fill the reserved STA_ID field within the HE-SIG-B field to extend the length of the preamble.
[0020] In one embodiment, the wireless communication module 114 may set the MCS in the HE-SIG-A field to indicate the MCS applied to one or more fields of the preamble, such as HE-SIG-B, so that the wireless communication module 114 may select a lower MCS for the HE-SIG-B symbol to extend the length of the preamble.
[0021] The HE-LTF field contains multiple HE-LTF symbols for channel estimation, and the HE physical layer provides support for HE-LTF symbol durations of 3.2 µs (1x), 6.4 µs (2x), and 12.8 µs (4x). In this embodiment, the wireless communication module 114 may intentionally control the HE-LTF field to have a greater number of symbols than required for channel estimation. In one embodiment, the wireless communication module 114 may intentionally control the HE-LTF field to have the maximum allowed number of symbols. Furthermore, the wireless communication module 114 may configure the HE-LTF field to support the maximum HE-LTF symbol duration (e.g., 12.8 µs (4x)) and the maximum guard interval.
[0022] Furthermore, the embodiments described above for extending the preamble length can be combined with each other. For example, the length of the preamble can be extended using at least some of the above-described HE-SIG-B symbol quantity control, DCM control, padding to retain the STA_ID field, HE-SIG-B-MCS, and HE-SIG-B symbol quantity control.
[0023] Figure 4 This diagram illustrates the operation of a wireless communication module according to an embodiment of the present invention. Figure 4 In the example shown, the wireless communication module 114 performs a backoff operation to initiate PPDU transmission, determines Enhanced Distributed Channel Access Function (EDCAF) and initiates MPDU aggregation; and checks Clear Channel Assessment (CCA) and elevates the MAC layer to physical layer transmission. See also Figure 4 By intentionally extending the preamble of the PPDU, all or most of the data fields of the PPDU can be transmitted when the PCIe is fully awake. Therefore, the PPDU does not need to add any virtual delimiters to the data fields, or only a small number of virtual delimiters are needed. Furthermore, since the HE-SIG-B field of the preamble is transmitted with a low modulation and coding scheme (MCS) and a single spatial stream (ISS), while the data fields of the PPDU are typically transmitted with a higher MCS and / or two or more spatial streams, the increased power consumption by extending the preamble will be far less than the increased power consumption by adding virtual delimiters to the data fields. Additionally, adding more HE-LTF symbols to the HE-LTF field for channel estimation can improve receiver sensitivity without significantly increasing power consumption.
[0024] In one embodiment, the aforementioned preamble duration control mechanism is used only to generate the first PPDU when the wireless communication module 114 has just transitioned from a low-power state to a normal state. That is, Figure 4The second PPDU generated immediately following the first PPDU, as shown, does not use the aforementioned preamble control mechanism, or only uses a portion of it. In the first example, the wireless communication module 114 extends the preamble of the first PPDU by controlling the HE-SIG-B field to have the maximum allowed number of symbols. However, the wireless communication module 114 does not intentionally extend the preamble of the second PPDU, such that the HE-SIG-B field contains only the number of symbols required to record all resource unit allocation information (i.e., the number of symbols in the HE-SIG-B field of the second PPDU may be less than the maximum allowed number of symbols). In the second example, the wireless communication module 114 controls the HE-SIG-B field of the preamble of the first PPDU to include a DCM indicator bit, indicating that DCM is applied to one or more fields of the preamble. Conversely, the wireless communication module 114 controls the HE-SIG-B field of the preamble of the second PPDU to include a DCM indicator bit, indicating that DCM is not applied to one or more fields of the preamble. In the third example, the wireless communication module 114 controls the HE-LTF field of the preamble of the first PPDU to have the maximum allowed number of symbols, but the wireless communication module 114 does not control the HE-LTF field of the preamble of the second PPDU to have the maximum allowed number of symbols (i.e., the number of symbols in the HE-LTF field of the second PPDU may be less than the maximum allowed number of symbols). In the fourth embodiment, the wireless communication module 114 controls the HE-SIG-B symbols of the preamble of the first PPDU to correspond to the first MCS, but the wireless communication module 114 controls the HE-SIG-B symbols of the preamble of the second PPDU to correspond to the second MCS, which is higher than the first MCS.
[0025] It should be noted that the above embodiments use HE PPDU 300 as an example, but this feature is not a limitation of the present invention. In other embodiments, the control method of the present invention can be applied to other types of PPDUs, such as Ultra High Throughput (EHT) PPDUs or Ultra High Reliability (UHR) PPDUs, and one or more fields of the preamble of the PPDU can be configured to extend the length of the PPDU preamble. For example, a specified field of the PPDU preamble can have a maximum allowed number of symbols, or a specified field of the PPDU preamble can include a DCM indicator bit indicating that DCM is applied to one or more fields of the preamble, or a specified field of the PPDU preamble can be configured to indicate that a lower MCS is applied in one or more fields of the preamble.
[0026] In short, in the control method of the wireless communication module of the present invention, by deliberately extending the preamble of the PPDU, all or most of the data fields of the PPDU can be transmitted when the PCIe is fully awake. Therefore, the PPDU does not need to add any virtual delimiters to the data fields, or only a small number of virtual delimiters need to be added to the data fields, so as to avoid the high power consumption problem caused by transmitting virtual delimiters at a higher data rate in the prior art.
[0027] Those skilled in the art will readily observe that many modifications and changes can be made to the apparatus and methods while retaining the teachings of the present invention. Therefore, the foregoing disclosure should be limited only to the scope of protection claimed in the dependent claims.
Claims
1. A method for controlling the duration of the preamble of a physical layer protocol data unit, comprising: It begins to transition from a low-power state to a normal state; Acquire multiple Media Access Control Protocol Data Units (MPDUs); The preamble is generated and its length is extended by adding unnecessary or redundant information to the preamble, or by adjusting the rate of the preamble. as well as Physical layer protocol data units (PPDUs) are generated by using a preamble and multiple MPDUs.
2. The control method of claim 1, wherein the steps of generating a preamble and extending its length by adding unnecessary or redundant information to the preamble, or by adjusting the rate of the preamble, include: Control the specified field of the preamble to have more symbols than is required to record all resource unit allocation information.
3. The control method of claim 2, wherein the step of controlling a specified field of the preamble to have a greater number of symbols than the number of symbols required to record all resource unit allocation information includes: Intentionally control the specified field to have the maximum allowed number of symbols.
4. The control method as described in claim 2, wherein the specified field is the HE-SIG-A field or the HE-SIG-B field of the preamble.
5. The control method as described in claim 2, wherein the specified field is the HE-LTF field of the preamble.
6. The control method of claim 1, wherein the steps of generating a preamble and extending its length by adding unnecessary or redundant information to the preamble, or by adjusting the rate of the preamble, include: Controls the specified field to include a dual-carrier modulation (DCM) indicator bit, indicating that the DCM is applied to one or more fields of the preamble.
7. The control method as described in claim 6, wherein the specified field is the HE-SIG-A field of the preamble.
8. The control method of claim 1, wherein the steps of generating a preamble and extending its length by adding unnecessary or redundant information to the preamble, or by adjusting the rate of the preamble, include: Control the specified field to reduce the modulation and coding scheme (MCS) settings of the preamble.
9. The control method as described in claim 8, wherein the specified field is the HE-SIG-A field of the preamble.
10. The control method as described in claim 1, wherein the PPDU is the first PPDU when the wireless communication module just enters the normal state from the low power state.
11. The control method of claim 10, wherein the plurality of MPDUs are a plurality of first MPDUs, the preamble is a first preamble, and the control method further comprises: Retrieve multiple second MPDUs; Generate a second preamble without extending its length by adding unnecessary or redundant information, or generate a second preamble using only some unnecessary or redundant information, or generate a second preamble without adjusting its rate; and The second PPDU is generated by using a second preamble and multiple second MPDUs.
12. The control method of claim 11, wherein the second PPDU is generated immediately after the first PPDU.
13. The control method of claim 11, wherein the steps of generating a preamble and extending its length by adding unnecessary or redundant information to the preamble, or by adjusting the rate of the preamble, include: Control the specified field of the preamble to have more symbols than is required to record all resource unit allocation information; as well as The steps for generating a second preamble without extending its length by adding unnecessary or redundant information, or by generating a second preamble using only some unnecessary or redundant information, include: Control the specified fields of the second preamble so that the second preamble contains only the number of symbols required to record all resource unit allocation information.
14. The control method of claim 13, wherein the specified field is the HE-SIG-A field or the HE-SIG-B field of the preamble.
15. A means for controlling the duration of the preamble of a physical layer protocol data unit, the means including a wireless communication module configured to perform the following steps: It transitions from a low-power state to a normal state. Acquire multiple Media Access Control Protocol Data Units (MPDUs); Generate a preamble and extend its length by adding unnecessary or redundant information to it or by adjusting its rate; and generate a Physical Layer Protocol Data Unit (PPDU) using the preamble and the plurality of MPDUs.
16. The wireless communication module of claim 15, wherein the step of generating a preamble and extending the length of the preamble by adding unnecessary or redundant information to the preamble includes: Control the specified field of the preamble to have a higher number of symbols than the number of symbols in the specified field is sufficient to record all resource unit allocation information.
17. The wireless communication module of claim 16, wherein the step of controlling a designated field of the preamble to have a higher number of symbols than the number of symbols sufficient to record all resource unit allocation information comprises: Intentionally control the specified field to have the maximum allowed number of symbols.
18. The wireless communication module of claim 16, wherein the designated field is the HE-SIG-A field or the HE-SIG-B field of the preamble.
19. The wireless communication module of claim 16, wherein the designated field is the HE-LTF field of the preamble.
20. The wireless communication module of claim 15, wherein the PPDU is the first PPDU when the wireless communication module has just entered the normal state from the low power state.