CN107534955B

CN107534955B - Resource indication processing method, processing device, access point and station

Info

Publication number: CN107534955B
Application number: CN201580079147.7A
Authority: CN
Inventors: 刘乐; 杨讯; 淦明; 吴伟民; 于健; 郭宇宸
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2015-06-29
Filing date: 2015-06-29
Publication date: 2020-02-14
Anticipated expiration: 2035-06-29
Also published as: CN107534955A; WO2017000133A1

Abstract

In a wireless local area network, in a TXOP, at least a first time interval and a second time interval after the first time interval are included, and at least before the first time interval, an access point AP of the wireless local area network sends a PPDU physical layer frame header, where the PPDU physical layer frame header includes information I1 for indicating whether an uplink trigger frame UL trigger exists in the TXOP; the AP sends downlink STA data in the first time interval; when the information I1 indicates that the UL trigger exists, the AP sends the uplink trigger frame UL trigger including uplink scheduling information at the second time interval.

Description

Resource indication processing method, processing device, access point and station

Technical Field

The present invention relates to the field of wireless communication technology, and more particularly, to a method, an access point, and a station for transmitting information.

Background

With the development of mobile internet and the popularization of intelligent terminals, data traffic is rapidly increasing. Wireless Local Area Network (WLAN) is one of the mainstream mobile broadband access technologies due to its advantages of high speed and low cost.

In order to greatly increase the service transmission rate of the WLAN system, the next generation of Institute of Electrical and Electronics Engineers (IEEE) 802.11ax standard further adopts Orthogonal Frequency Division Multiple Access (OFDMA) technology based on the existing Orthogonal Frequency Division Multiplexing (OFDM) technology. OFDMA divides the time-frequency resources of air-interface radio channels into multiple orthogonal time-frequency Resource Blocks (RBs), which may be shared in time and orthogonal in frequency domain.

OFDMA techniques support multiple nodes to transmit and receive data simultaneously. When the access point needs to transmit data with the station, resource allocation is carried out based on the RB or the RB group; different channel resources are allocated to different STAs at the same time, so that a plurality of STAs can be efficiently accessed into a channel, and the channel utilization rate is improved.

Specifically, for uplink multi-STA transmission, the access point AP needs to send a trigger frame (UL trigger), which may generally include but is not limited to one of the following information: each STA ID, allocation resources, and other scheduling information, such as frequency resources, time resources, spatial stream resources, Modulation and Coding Scheme (MCS), coding type, transmit diversity, or power control information. The multi-STA scheduling information may be sent in a MAC frame in a packet manner, which is referred to as MAC trigger, or may be sent in PHY signaling, which is referred to as PHY trigger.

How to efficiently transmit the UL trigger is a concern of embodiments of the present invention.

Disclosure of Invention

The embodiment of the invention provides a method, an access point and a site for transmitting information, which can efficiently and effectively send UL trigger.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of a system architecture to which embodiments of the present invention are applicable.

Fig. 2 is a flow diagram that illustrates an example of the applicability of an embodiment of the present invention.

Fig. 3 is a diagram of an uplink trigger frame according to an embodiment of the present invention.

Fig. 4 is a diagram of an uplink trigger frame according to an embodiment of the present invention.

Fig. 5a, 5b, 6, and 7 are diagrams of frames of TXOP according to an embodiment of the present invention.

Fig. 8 is a diagram of a MAC header according to another embodiment of the present invention.

Fig. 9a and 9b are diagrams of TXOP according to an embodiment of the present invention.

Fig. 10a, 10b, and 10c are diagrams of TXOP according to an embodiment of the present invention.

Fig. 11 is a block diagram of an access point of an embodiment of the present invention.

Fig. 12 is a block diagram of a station of an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

An Access Point (AP), which may also be referred to as a wireless Access Point or a bridge or a hotspot, may Access a server or a communication network. Which is itself a site.

A Station (STA), which may also be referred to as STA or Non-AP STA, may be a wireless sensor, a wireless communication terminal or a mobile terminal, such as a mobile phone (or referred to as "cellular" phone) supporting WiFi communication function and a computer having a wireless communication function. For example, the wireless communication devices may be portable, pocket-sized, hand-held, computer-embedded, wearable, or vehicle-mounted devices that support WiFi communication functionality, which exchange voice, data, etc. communication data with a radio access network.

Fig. 1 is a simplified schematic diagram of a WLAN system to which an embodiment of the present invention is applied. The system of fig. 1 includes one or more access points AP101 and one or more station STAs 102. The access point 101 and the station 102 perform wireless communication by using OFDMA technology, where a data frame transmitted by the access point 101 includes UL trigger for the station 102.

Specifically, referring to fig. 2, an embodiment of the present invention provides a method for triggering frame transmission, which is applied to a wireless local area network using an OFDMA technique, and includes:

in a wireless local area network, within one TXOP, at least a first time interval and a second time interval after the first time interval are included,

at least before the first time interval, the AP sends a PPDU physical layer frame header, wherein the PPDU physical layer frame header comprises information I1 used for indicating whether the uplink trigger frame UL trigger exists in the TXOP;

an Access Point (AP) of the wireless local area network sends downlink STA data in the first time interval;

and the AP sends an uplink trigger frame UL trigger containing uplink scheduling information at the second time interval.

The scheme can efficiently and flexibly send downlink and uplink multi-STA data in a single TXOP in a cascade mode, and can further have one or more of the following beneficial effects: and the additional overhead is reduced, or the reliability of uplink transmission is improved.

In one embodiment, multiple time intervals are allocated in the same TXOP, and in one of the time intervals, the AP sends a trigger frame for triggering uplink transmission, where the trigger frame includes scheduling information of the STA, which is referred to as an uplink trigger frame UL trigger. In this embodiment, preferably, the UL trigger is an MAC trigger that transmits uplink scheduling information in an MAC frame. Therefore, after the AP sends the multi-STA downlink data in the same TXOP, the UL trigger can be sent without waiting for SIFS time or adding a Legacy physical layer frame header Legacy preamble. It can be known that ULtrigger and other downlink data are time-division multiplexed in one downlink DL frame.

Embodiments of the present invention relate to, but are not limited to, the following aspects:

first, information I1 about indicating UL trigger

The PPDU sent by the AP includes a PPDU physical layer frame header before downlink data. The PPDU physical layer frame header sent by the AP includes information I1 indicating whether an UL trigger exists in the TXOP. Preferably, the information I1 may be located in L-SIG, repeated L-SIG symbol (RL-SIG) or HE-SIG-A in PPDU physical layer frame header.

Preferably, the information I1 is indicated in an implicit manner.

In one example, a method for indicating information of UL trigger is provided, where setting of L-LENGTH in L-SIG is used to indicate whether UL trigger exists in the TXOP: when the L-LENGTH is an integral multiple of 3, indicating that no UL trigger exists in the TXOP; when the transmitting end sets that L-LENGTH is not an integer multiple of 3, (the remainder of the division by 3 is not 0), indicating that UL trigger exists in the TXOP. Or vice versa.

In another example, a method of indicating UL trigger information is provided, which indicates whether UL trigger exists using a phase change of an information bit of a repeated L-SIG (RL-SIG): for example, if the RL-SIG and L-SIG phases are the same, indicating that an UL trigger exists; if the RL-SIG and L-SIG are in opposite phases, the UL trigger is indicated to be absent. Or vice versa.

In another example, a method for indicating UL trigger information is provided, where an 802.11ax device may identify a pilot subcarrier by using 4 bits additionally added to the L-SIG on both sides of the conventional 48 bits, and the pilot subcarrier may obtain channel estimates for 4 subcarriers, and the channel estimates for 48 subcarriers obtained by L-LTF are used to receive information on 52 carriers of a subsequent HE-SIG-a. The phase change of 4 additional pilot subcarriers may be utilized here to indicate whether an UL trigger is present. For example, 4 subcarriers are respectively located at the left and right of the DC tone, and 2 subcarriers are a group, and if the left and right phases are the same, it indicates that there is no subcarrier, and if the left and right phases are opposite, it indicates that there is subcarrier.

In another example of this, a method for indicating UL trigger information is provided, which uses the phase change of 4 pilot tones in RL-SIG to indicate if UL trigger exists.

In another example, a method of indicating information of UL trigger is provided, which explicitly indicates that UL trigger exists within the TXOP by using 1 bit in HE-SIG-a.

In addition, in the HE-SIG-a or HE-SIG-B in the PPDU physical layer frame header sent by the AP, information I2 or information I3 indicating the position or length of the uplink trigger frame UL trigger, information such as a transmission mode, for example, a time when the UL trigger starts/ends within the TXOP, or a duration of the UL trigger (unit ms), or a multiple of a unit time (for example, 0.1ms), or a number of unit symbols required by the UL trigger, a transmitted data amount, a specified MCS (the duration may be calculated according to the specified MCS and the transmitted data amount), and the like are included. The UL trigger transmission mode includes MCS, symbol length, inter-symbol interval, etc. A symbol length, such as 3.2us symbol length with conventional 11a/n/ac, or 12.8us symbol length with 11 ax; inter-symbol interval gi (guard interval) or symbol prefix cp (cyclic prefix), such as 0.4us or 0.8us for indoor channel environment, or 1.6us or 3.2us for outdoor channel environment, etc. The indication of the symbol interval can reuse or partially reuse the indication of the downlink PPDU, and if the symbol length is fixed to 3.2us indoors and fixed to 12.8us outdoors, the indication can also be omitted, the MCS indication can specify default low MCS or select from a limited number of MCS, and the overhead of the MCS indication information of UL trigger can be saved.

In a preferred example, if it is further indicated in advance which STAs to detect the UL trigger, the STA ID or the STA group ID of the UL trigger may be indicated in the frame header HE-SIG-B of the downlink PPDU. If the STA sequence indicated by the HE-SIG-B is adopted, the indication of the STA id may be omitted from the UL trigger, and other scheduling information of each STA or the STA group may be indicated in sequence.

In a preferred example, the default UL trigger is located at the last position of the PPDU sent by the AP, and the end position I2-1 is not required to be indicated, in this case, only the length I3 of the UL trigger needs to be indicated, where the length may be a time interval, or a multiple of a unit time interval, or a number of unit symbols, and the length information may be obtained by calculation through a specified MCS and a transmission data amount. The receiving end (uplink STA) can know the position where the UL trigger starts by subtracting the length of the UL trigger from the length of the PPDU in the L-SIG, and the downlink STA can know the position where the downlink data ends. If the downlink STA needs to feed back ACK information after waiting for SIFS time after the end of the downlink PPDU through AP scheduling, or the STA has data waiting for the AP to schedule uplink transmission and is an uplink STA at the same time, whether uplink transmission scheduling information of the STA exists in UL trigger needs to be read; otherwise, the downlink STA does not need to read the UL trigger. If a downlink STA delays ACK (acknowledgement character) of downlink data of the STA or the STA does not wait for uplink data scheduled by the AP, the scheduling information of the STA does not need to be detected in an UL trigger; otherwise, the STA detects the scheduling information related to the STA in the UL trigger.

In another example, the default UL trigger is located at the beginning of the data portion in the downlink frame, the starting position I2-2 is not required to be indicated, only the length I2 of the UL trigger is required to be indicated, the uplink STA can know the end point of the UL trigger, and the downlink STA can know the beginning position of the downlink data.

If the UL trigger exists, the receiving end can know the accurate position and the length of the UL trigger according to the related indication about the UL trigger in the HE-SIG-A or the HE-SIG-B. If the receiving end is an uplink STA waiting for scheduling transmission of uplink data, the scheduling information of uplink transmission of the STA may be detected from the UL trigger, and the scheduling information may include but is not limited to one of the following information: each uplink STA identifies the number ID, allocation resources, and other scheduling information, such as frequency resources, time resources, spatial stream resources, Modulation and Coding Scheme (MCS), coding type, transmit diversity, or power control information. .

And if the STA finds that the scheduling information of the STA downlink data exists in the HE-SIG-B, the STA continues to detect the downlink data in the allocated resources, and if the STA needs the AP to schedule and send the ACK of the downlink data, the STA waits until ULtrigger starts to detect the scheduling information of the STA uplink sending the ACK. And if the STA needs to be scheduled by the AP to send uplink data, waiting for the UL trigger to start to detect the uplink scheduling information of the STA.

Second, transmission mode related to UL trigger

Preferably, the UL trigger is sent as a part of the 802.11ax downlink data packet, and may be sent over the full bandwidth on the total bandwidth designated by the AP to the UL trigger, or repeatedly sent over the unit bandwidth within the total bandwidth. In order to improve the transmission efficiency, information in each unit bandwidth may be transmitted in parallel in the unit bandwidth in the total bandwidth. Here, the unit bandwidth is specified to be 20MHz or more and 40MHz, such as total bandwidth of 80MHz, unit bandwidth of 20 MHz; bandwidth of 160MHz or 80+80MHz, unit bandwidth of 40 MHz). The total bandwidth specified by the AP to the UL trigger may be the same as the total bandwidth of the downlink data packet, and reuse the downlink bandwidth indication information, or may be different from the total bandwidth of the downlink data packet, but needs an additional signaling indication. The difference from the conventional scheme is that in the transmission time of the UL trigger, the frequency resource is not shared with other downlink data, but only the information of the UL trigger.

The length of the transmitted symbol may be the same as the data portion specified by the protocol of the next generation Wifi standard (for example, but not limited to 802.11ax), for example, (CP +12.8us), at this time, HE-STF and HE-LTF need to be sent before the MAC trigger information, so as to help the uplink STA to obtain the UL trigger-related power control information and channel estimation information. If the legacy symbol length (CP +3.2us) of the Wifi standard (e.g., 802.11 series) is used, the receiver already obtains power control information and channel estimation information from the L-STF and L-LTF at the beginning of the frame, and HE-STF/HE-LTF can be omitted. The inter-symbol interval CP may be designated as one of 0.4us, 0.8us, 1.6us, or 3.2 us. The indication of the symbol interval can reuse or partially reuse the indication of the downlink PPDU, and if the symbol length is fixed to 3.2us indoors and fixed to 12.8us outdoors, the indication can also be omitted, the MCS indication can specify default low MCS or select from a limited number of MCS, and the overhead of the MCS indication information of UL trigger can be saved.

Third, trigger information contained in the UL trigger

The UL trigger includes scheduling information for triggering uplink transmission, and at least includes one of the following:

scheduling information that triggers the downlink STA to send an ACK, and/or,

and triggering the uplink STA to send the scheduling information of the uplink data.

Wherein the uplink STA in the UL trigger here may be different from the downlink STA. The uplink STA is an STA that transmits uplink data, the downlink STA is an STA that receives downlink data, and the downlink STA needs to feed back an ACK to the AP after correctly receiving the downlink data. If the STA has uplink data and downlink data at the same time, the STA is both an uplink STA and a downlink STA.

Fourth, data structure for UL trigger

The UL trigger in each embodiment may be a MAC frame, which is abbreviated as MAC trigger and is a special control frame. The content or structure of the MAC Frame is shown in fig. 4, where Frame Control (FC), Duration, transmitteraddress (ta) are all contents in a conventional MAC Frame, and are respectively used to identify the MAC Frame type, transmission time, source address, and the like. The latter indication information is scheduling information that triggers the STA.

As shown in fig. 3, the scheduling information indicates uplink transmission scheduling information of each STA, which is referred to as STA-based mac trigger for short. The STA may be a downlink STA, and the scheduling information indicates an ID of the STA, and resource allocation information for uplink transmission of ACK by the downlink STA and scheduling information for other indication transmission, or an uplink STA, and the scheduling information indicates an ID of the STA, and resource allocation information for uplink transmission of uplink data by the uplink STA and scheduling information for other indication transmission. If the STA has downlink data and uplink data at the same time, the AP allocates resources to the STA to send ACK and uplink data of the downlink data at the same time, the STA's related information indicates the STA's ID at the same time, and the location and size of the frequency-time resources allocated to send ACK and uplink data of the downlink data, and in addition, other scheduling information of the STA, such as Coding type and transmit diversity, and power control information may also be used for ACK and uplink data of the downlink data at the same time, but other scheduling information, such as Modulation and Coding Scheme (MCS) and spatial stream, etc., ACK and uplink data of the downlink data may be different, and generally ACK of the downlink data is transmitted with the lowest MCSO for correct detection, and uplink data may be transmitted according to the MCS indicated by the AP; and the ACK of the downlink data adopts a single stream, and the uplink data can be transmitted according to the spatial stream indicated by the AP.

As shown in fig. 4, the scheduling information indicates uplink transmission scheduling information of each resource unit (RU, resource unit), which is abbreviated as RU-based MAC trigger. The common field includes RU resource allocation information, which indicates the location and size of each RU, and subsequently indicates scheduling information for allocating STAs or a group of STAs in each RU. The STA in each RU may be a downlink STA whose scheduling information indicates an ID of the STA, and resource allocation information for uplink transmission of ACK and other scheduling information for uplink transmission by the downlink STA, or an uplink STA whose scheduling information indicates an ID of the STA, and resource allocation information for uplink transmission of uplink data by the uplink STA and other scheduling information for uplink transmission. If the STA in the RU has downlink data and uplink data at the same time, the RU sends ACK and uplink data of the downlink data to the STA at the same time, the STA related information indicates the STA ID at the same time, and the position and size of the frequency-time resource allocated to send ACK and uplink data of the downlink data, and in addition, other scheduling information of the STA, such as coding type and transmit diversity, may also be used for ACK and uplink data of the downlink data at the same time, but other scheduling information, such as Modulation and Coding Scheme (MCS) and spatial stream, may be different for ACK and uplink data of the downlink data, and usually ACK of the downlink data is transmitted with the lowest MCSO for correct detection, and uplink data may be transmitted according to the MCS indicated by the AP; and the ACK of the downlink data adopts a single stream, and the uplink data can be transmitted according to the spatial stream indicated by the AP.

Fifth, processing on the STA side of the receiving end

The receiving end STA receives the aforementioned corresponding information sent by the AP. If the STA obtains the presence of the UL trigger in the TXOP in the indication information in the DL PPDU of the earlier part (e.g., the starting position) of the TXOP, and in addition, the accurate position and length of the UL trigger can be obtained according to the indication about the position or length of the UL trigger, the STA without downlink data but waiting for the uplink scheduling may skip the downlink data time and wait until the UL trigger detects the scheduling information again, while the STA without downlink data may also skip the entire TXOP time without waiting for the uplink scheduling, and does not perform information detection. In contrast, if it is known that the UL trigger does not exist, the STA waiting for scheduling finds that it is not necessary to search the uplink scheduling information of the STA in the TXOP.

Example one

In this example, the ACK of the downlink STA and the uplink STA data share the uplink resource, and the scheduling information sent in the UL trigger includes:

triggering a downlink STA to send scheduling information of ACK; and triggering the uplink STA to send the scheduling information of the uplink data.

In other examples, OFDMA may be used, as shown in fig. 5 a. If the downlink STA only sends ACK without extra uplink data, it can also send in TDM (time division multiplexing) manner, as shown in fig. 5 b. In the TDM manner, the ACK information of the downlink STA is located in front of the uplink data, because the ACK information is shorter than the uplink data, the front ACK information does not affect the time and frequency synchronization when the subsequent uplink STA sends the uplink data. The downlink STA can send ACK together with the uplink data of the downlink STA, and the AP allocates corresponding resources according to the ACK information and the size of the uplink data.

The effect of example one:

in this example, after the AP sends the downlink data, the AP directly sends the trigger frame without waiting for the SIFS, which saves time for separately sending the SIFS and the L-preamble, etc., required by the UL trigger, and energy for sending the L-preamble.

In this example, the UL trigger and the downlink data are independently allocated with frequency resources in different time intervals, so that the complexity of resource scheduling is reduced, and resource waste or receiving performance is not affected due to mismatching between the UL trigger information and the uplink STA.

In this example, the ACK/downlink data and the uplink data of the downlink STA are jointly scheduled, so that the uplink transmission performance is ensured by scheduling and allocating resources with good conditions according to the STA channel conditions while improving the spectrum utilization efficiency.

Preferably, if the existence of the UL trigger is known, the uplink/downlink STA can know the accurate position and length of the UL trigger according to the indication about the UL trigger in the HE-SIG-a or the HE-SIG-B, and the uplink waiting scheduling STA can skip the downlink data and the like until the UL trigger detects the scheduling information. On the contrary, if it is known that the UL trigger does not exist, the STA waiting for scheduling may ignore the TXOP and not detect the uplink scheduling information.

Here, part of the STAs in the UL trigger are UL STAs, and unlike DL STAs, placing the UL trigger behind the data of the DL STA can delay time for the DL STA, so as to ensure that there is enough processing time before SIFS without adding extra time extension symbols. However, if the STA scheduled in the UL trigger is the same as the DL STA, the STA needs to detect the scheduling information of the STA in the UL trigger immediately after receiving the downlink data, so if the downlink data of the STA is transmitted in a large RU with a high MCS, a low-power STA needs to insert an extra symbol between the DL data time and the UL trigger if the downlink data processing time is not enough, and the processing time is prolonged.

Example two

In this example, the UL trigger allocates resources only for the ACK of the downlink STA, and there is no data of other uplink STAs. Then the sending of scheduling information in the UL trigger includes:

and triggering the downlink STA to send scheduling information of the ACK.

Here, the UL trigger is the same as the downlink scheduling STA, and the scheduling information in the UL trigger can be further saved according to the fact that the downlink STA specifies the relevant scheduling information of the downlink data in the HE-SIG-B. For example, in the same STA order or RU order as in the HE-SIG-B, the STA ID in each STA scheduling information or the ID of each RU scheduling STA can be saved. In addition, the UL trigger indicates ACK uplink transmission, and special ACK transmission may be selected by default to use single stream, BCC coding, non-transmission rank, and lowest MCS transmission, so that the scheduling information of each STA or each RU in the UL trigger may omit MCS, transmission rank mode, coding type, spatial stream information, and the like, and may be simplified to indicate time-frequency resource allocation information allocated for uplink transmission.

As shown in fig. 6, after the UL trigger (the MAC trigger for DL STA shown in fig. 6) passes through the SIFS time, the downlink STA sends an ACK according to the scheduling information. Therefore, when the downlink STA transmits in the uplink, the frequency resource with the best channel quality is selected to transmit the ACK according to the size required by the ACK control signaling and the uplink channel quality, so that the extra resource waste is avoided, and the detection quality is improved; for MU-MIMO STAs (such as STA2, 3 in fig. 6) sharing downlink allocation resources, uplink transmission ACK cannot be transmitted in parallel by using MU-MIMO, and the AP needs to reallocate frequency resources at the time of uplink OFDMA transmission according to the uplink channel quality of each STA in MU-MIMO. The UL trigger provides scheduling information specific to uplink transmission to indicate that the allocation of ACK information for downlink OFDMA + MU-MIMO multi-STA is more flexible. Especially for the MU-mimo sta sharing the same frequency resource in downlink, the uplink ACK needs to be sent by OFDMA to ensure the detection performance, and additional resources need to be allocated.

The second embodiment is a special case of the first embodiment, so that the foregoing advantages are provided, and a flexible application is provided in the case where the downlink STA needs to immediately feed back while no new uplink STA transmits uplink data.

Example three

In this example, the UL trigger allocates resources only for the data of the uplink STA. Then the transmission scheduling information in the UL trigger includes

Triggering an uplink STA to send scheduling information of uplink data;

as shown in fig. 7, after SIFS time elapses after UL trigger (MAC trigger for UL STA4, 5, 6), the uplink STA transmits uplink data according to the scheduling information. The ACK of the downlink STA is not fed back immediately after waiting for SIFS time after the downlink data is sent, and the ACK is delayed to be fed back and the uplink STA data is prioritized. The indication of how to delay feedback ACK may be indicated in the QoS control in the MAC header of the downlink STA data frame or the HEcontrol, as shown in fig. 8, which is the same as the definition in the legacy 11ac for the QoScontrol in 802.11ax, and includes the ACK feedback format after receiving the data packet and the indication of whether feedback is delayed or not.

The MAC header refers to a MAC frame header part in a general packet, wherein some system signaling indication related to the packet is provided. The MAC trigger is a special control frame, not a data packet, and the data structure thereof can refer to the foregoing embodiment.

The third embodiment is a special case of the first embodiment, so similar advantages are provided, and a flexible application is provided in the case that the downlink STA delays feedback and a new uplink STA sends uplink data.

Example four

The UL trigger allocates resources only for the data of the uplink STA. Then the transmission scheduling information in the UL trigger includes

Triggering an uplink STA to send scheduling information of uplink data;

such as:

in this example, after SIFS time passes after UL trigger, the uplink STA transmits uplink data according to the scheduling information. The ACK of the downlink STA also waits for SIFS time feedback after downlink data transmission, but the indication information how the downlink STA feeds back the ACK is indicated in the 11ax specific control field HE control after the QoS control in each downlink STA data frame MAC header, as shown in fig. 8. The HE control includes a resource indication of uplink transmission (ACK feedback or uplink data transmission) of the downlink STA, including allocated resources and other scheduling information, such as frequency resources, time resources, spatial stream resources, modulation and coding rate, coding type, transmit diversity, and power control information. Since the scheduling information triggering uplink transmission is only for the STA, the ID of the STA is already indicated in the destination address field in the downlink packet without repeating the indication in the HEcontrol. The OFDMA scheme is adopted, as shown in fig. 9 a. If the downlink STA only transmits ACK without additional uplink data, it also transmits in TDM manner, as shown in fig. 9 b. The ACK information of the downlink STA is placed in front of the uplink data in the TDM mode, and because the ACK information is shorter relative to the uplink data, the time and frequency synchronization when the subsequent uplink STA sends the uplink data cannot be influenced when the ACK information is placed in front. The downlink STA can send ACK together with own data when sending ACK, and the AP allocates corresponding resources according to the ACK information and the size of the uplink data.

The ACK/downlink data and the uplink data of the downlink STA are jointly scheduled, so that the spectrum utilization efficiency is improved, and simultaneously, the uplink transmission performance is ensured by scheduling and allocating resources with good conditions according to the STA channel conditions.

Example four in addition to having similar advantages as the examples, there are also unique advantages:

here, the STA in the UL trigger is a UL STA and is completely different from the DL STA, so that after the DL STA receives the downlink data, it is not necessary to detect the UL trigger, and before preparing the uplink feedback ACK of the STA or transmitting the uplink data, the UL trigger immediately following the downlink data may leave enough processing time without adding an extra time extension symbol.

It should be explained that the MAC header is a MAC frame header part in a general packet, wherein some system signaling indication is related to the packet. The MAC trigger is a special control frame and is not a data packet. Each PPDU has a MAC header, the MAC header of a general packet is defined as shown in fig. 8, and the MAC trigger is a control frame different from the packet, and the MAC header of the packet are defined differently, for example, as shown in fig. 4.

Example five

If one TXOP includes multiple downlink and uplink concatenated PPDUs, one uplink STA may be indicated in one UL trigger to transmit in a certain subsequent uplink PPDU, as shown in fig. 10a, 10b, and 10 c. Then, in the scheduling information corresponding to the STA, the resource indication needs to include a location of a specific uplink PPDU, such as a start time and a transmission time or an end time of a specified uplink PPDU in the TXOP, where the time may be an absolute time or a multiple of a specified unit time (a symbol or several symbols are a unit); it may also be simplified that the common info field common information field of the UL trigger indicates the length of each uplink PPDU in sequence, and the time resource indication information of the following STA or each RU indicates that the specified uplink PPDU is the sequence number of the second in the TXOP.

Before each uplink PPDU, there are one or more DL PPDUs, so multiple STAs scheduled in each uplink PPDU can perform phase tracking by using pilot subcarriers in the previous downlink PPDU, and ensure synchronization on a designated time frequency after UL trigger.

The UL trigger in the TXOP in fig. 10a is attached to one downlink PPDU to transmit downlink multi-STA data, and may indicate related information (presence or absence, length information, and the like) of the UL trigger in a physical layer frame header of the downlink PPDU, so as to help the STA prepare to detect the UL trigger at a specified time in advance.

The UL trigger in the TXOP in fig. 10b is not attached to the downlink PPDU for transmitting downlink multi-STA data, but is sent after waiting for SIFS time after the downlink PPDU, and the MAC trigger needs to have its own physical layer frame header when being sent, if the format physical layer frame header of 11a includes legacy preamble, if the format physical layer frame header of 11n includes legacy preamble and HT-preamble, if the format physical layer frame header of 11ac includes legacy preamble and VHT-preamble, and if the format physical layer frame header of 11n includes legacy preamble and HE-preamble. Related information (existence or not, LENGTH information and the like) can be indicated in a frame header of a physical layer of a downlink PPDU in front of the UL trigger, the STA is helped to prepare for detecting the UL trigger at a specified time in advance, whether the UL trigger exists or not can be indicated only in a frame header of the physical layer of the downlink PPDU, if the UL trigger exists, the STA needs to indicate L-LENGTH in L-SIG for detecting the UL trigger, and the PPDU LENGTH of the UL trigger can be known.

In fig. 10c, the UL trigger in the TXOP does not depend on the downlink PPDU to transmit downlink multi-STA data, but at the beginning of the TXOP, the MAC trigger needs to have its own physical layer frame header when transmitting, if the format physical layer frame header of 11a includes legacy preamble, if the format physical layer frame header of 11n includes legacy preamble and HT-preamble, if the format physical layer frame header of 11ac includes legacy preamble and VHT-preamble, if the format physical layer frame header of 11n includes legacy preamble and HE-preamble. After detecting the UL trigger at the start of the TXOP, the STA can acquire the PPDU LENGTH of the UL trigger through the L-LENGTH indication in the L-SIG.

The fifth embodiment has the advantage that the advantage of the foregoing embodiment is inherited, and because the UL trigger includes scheduling information of a plurality of UL pdus, the waiting time and overhead of a physical layer/MAC layer frame header for independently sending a plurality of UL triggers for multiple times are saved, and the system efficiency can be further improved.

Accordingly, another embodiment provides an information transmission processing apparatus (not shown) applied in a wireless local area network, including a processing unit configured to: in a wireless local area network, within one TXOP, at least a first time interval and a second time interval after the first time interval are included,

sending a PPDU physical layer frame header at least before the first time interval, wherein the PPDU physical layer frame header comprises information I1 for indicating whether an uplink trigger frame UL trigger exists in the TXOP;

transmitting downlink STA data in the first time interval;

when the information I1 indicates that the UL trigger exists, the uplink trigger frame UL trigger including uplink scheduling information is sent at the second time interval. Alternatively, the first and second electrodes may be,

another embodiment provides an information transmission processing apparatus (not shown) applied to a wireless local area network, including a processing unit configured to: within one TXOP, at least a first time interval and a second time interval subsequent to the first time interval,

receiving a PPDU physical layer frame header at least before the first time interval, wherein the PPDU physical layer frame header comprises information I1 for indicating whether the uplink trigger frame UL trigger exists in the TXOP;

the station STA of the wireless local area network receives downlink STA data at the first time interval;

when the information I1 indicates that the UL trigger exists, the STA receives an uplink trigger frame UL trigger containing uplink scheduling information at the second time interval

For the specific frame structure and content, reference may be made to the foregoing embodiments, which are not described herein again. The processing unit may be a general purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, configured to implement or perform the methods, steps, and logic blocks disclosed in embodiments of the present invention. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor. It is easy to understand that, the processing device for resource indication may be located at the access point when specifically transmitting the frame including the resource indication field; and may be located at the station when receiving the frame including the resource indicator field.

Fig. 11 is a block diagram of an access point of another embodiment of the present invention. The access point of fig. 11 comprises an interface 101, a processing unit 102 and a memory 103. Processing unit 102 controls the operation of access point 100. Memory 103 may include both read-only memory and random access memory, and provides instructions and data to processing unit 102. A portion of the memory 103 may also include non-volatile row random access memory (NVRAM). The various components of access point 100 are coupled together by a bus system 109, where bus system 109 includes a power bus, a control bus, and a status signal bus in addition to a data bus. For clarity of illustration, however, the various buses are labeled in the figure as bus system 109.

The method for transmitting the foregoing frames according to the embodiments of the present invention may be applied to the processing unit 102, or implemented by the processing unit 102. In implementation, the steps in the above embodiments may be implemented by hardware integrated logic circuits in the processing unit 102 or instructions in the form of software. The processing unit 102 may be a general purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, configured to implement or perform the methods, steps, and logic blocks disclosed in embodiments of the present invention. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 103, and the processing unit 102 reads the information in the memory 103 and completes the steps of the above method in combination with the hardware thereof.

By way of example, the processing unit 102 is configured to implement the method of:

transmitting downlink STA data in the first time interval;

and sending the uplink trigger frame UL trigger containing uplink scheduling information at the second time interval.

Preferably, there is no time gap between the first time interval and the second time interval. Preferably, the uplink trigger frame is an MAC frame. Preferably, the uplink scheduling information at least includes one or two of the following information: scheduling information for triggering the downlink STA to send ACK; or, the scheduling information is used to trigger the uplink STA to send uplink data. Further details are provided with reference to the preceding embodiments and will not be described in detail here.

Fig. 12 is a block diagram of a station of another embodiment of the present invention. The station of fig. 12 comprises an interface 111, a processing unit 112 and a memory 113. Processing unit 112 controls the operation of station 110. Memory 113 may include both read-only memory and random access memory, and provides instructions and data to processing unit 112. A portion of the memory 113 may also include non-volatile row random access memory (NVRAM). The various components of station 110 are coupled together by a bus system 119, wherein bus system 119 includes a power bus, a control bus, and a status signal bus in addition to a data bus. But for clarity of illustration the various buses are labeled in the figure as the bus system 119.

The method for receiving information disclosed in the above embodiments of the present invention may be applied to the processing unit 112, or implemented by the processing unit 112. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processing unit 112. The processing unit 112 may be a general purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or the like that implement or perform the methods, steps, and logic blocks disclosed in embodiments of the present invention. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 113, and the processing unit 112 reads the information in the memory 113 and performs the steps of the above method in combination with the hardware thereof.

Specifically, memory 113 stores instructions that cause processing unit 112 to: determining resource state information which indicates the busy-idle state of sub-resources of channel resources for data transmission between the access point and the site; and sending the resource state information to the access point so that the access point can allocate the resources according to the resource state information.

By way of example, the processing unit 112 is configured to implement:

receiving downlink STA data in the first time interval;

and when the information I1 indicates that the UL trigger exists, receiving an uplink trigger frame UL trigger containing uplink scheduling information at the second time interval.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In various embodiments of the present invention, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

Additionally, the terms "system" and "network" are often used interchangeably herein. The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be understood that in the present embodiment, "B corresponding to a" means that B is associated with a, from which B can be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may be determined from a and/or other information.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be embodied in electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described in a functional general in the foregoing description for the purpose of illustrating clearly the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may also be an electric, mechanical or other form of connection.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment of the present invention.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

From the above description of the embodiments, it is clear to those skilled in the art that the present invention can be implemented by hardware, firmware, or a combination thereof. When implemented in software, the functions described above may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. Taking this as an example but not limiting: computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Furthermore, the method is simple. Any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, a server, or other remote sources using a coaxial cable, a fiber optic cable, a twisted pair, a Digital STA Line (DSL), or a wireless technology such as infrared, radio, and microwave, the coaxial cable, the fiber optic cable, the twisted pair, the DSL, or the wireless technology such as infrared, radio, and microwave are included in the fixation of the medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy Disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

In short, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for transmitting information is characterized in that in a wireless local area network, within a TXOP, at least a first time interval and a second time interval after the first time interval are included, and at least before the first time interval, an Access Point (AP) of the wireless local area network sends a PPDU physical layer frame header, wherein the PPDU physical layer frame header includes information I1 for indicating whether an uplink trigger frame (UL trigger) exists within the TXOP;

the AP sends downlink STA data in the first time interval;

when the information I1 indicates that the UL trigger exists, the AP sends the uplink trigger frame UL trigger including uplink scheduling information at the second time interval.

2. The method of claim 1, wherein there is no time gap between the first time interval and the second time interval.

3. The method according to claim 1 or 2, characterized in that the uplink trigger frame is a MAC frame.

4. The method of claim 1 or 2, wherein the information I1 is located in L-SIG, repeated L-SIG symbol RL-SIG or HE-SIG-a in the PPDU physical layer frame header.

5. The method according to claim 1 or 2, wherein the PPDU physical layer frame header comprises information I2 or information I3 for indicating the location or length of the UL trigger.

6. The method of claim 5, wherein the information I2 is located in HE-SIG-a or HE-SIG-B in a frame header of the PPDU physical layer; or

The information I3 is located in HE-SIG-A or HE-SIG-B in the PPDU physical layer frame header.

7. The method according to claim 1, 2 or 6, wherein the uplink scheduling information at least includes one or two of the following information: scheduling information for triggering the downlink STA to send ACK; or, the scheduling information is used to trigger the uplink STA to send uplink data.

8. A method for transmitting information is characterized in that in a wireless local area network, within a TXOP, at least a first time interval and a second time interval after the first time interval are included, and at least before the first time interval, a PPDU physical layer frame header is received, wherein the PPDU physical layer frame header includes information I1 for indicating whether an uplink trigger frame UL trigger exists in the TXOP;

when the information I1 indicates that the UL trigger exists, the STA receives an uplink trigger frame UL trigger containing uplink scheduling information at the second time interval.

9. The method of claim 8, wherein there is no time gap between the first time interval and the second time interval.

10. The method according to claim 8 or 9, characterized in that said uplink trigger frame is a MAC frame.

11. The method of claim 8 or 9, wherein the information I1 is located in L-SIG, repeated L-SIG symbol RL-SIG or HE-SIG-a in a frame header of the PPDU physical layer.

12. The method according to claim 8 or 9, wherein the PPDU physical layer frame header includes information I2 or information I3 for indicating the location or length of the UL trigger frame.

13. The method of claim 12, wherein the information I2 is located in HE-SIG-a or HE-SIG-B in a frame header of the PPDU physical layer; or

14. The method according to claim 8, 9 or 13, wherein the uplink scheduling information at least includes one or two of the following information: scheduling information for triggering the downlink STA to send ACK; or, the scheduling information is used to trigger the uplink STA to send uplink data.

15. An apparatus for transmitting information, comprising, within one TXOP, at least a first time interval and a second time interval that is subsequent to the first time interval;

the apparatus comprises a processing unit configured to:

transmitting downlink STA data in the first time interval;

when the information I1 indicates that the UL trigger exists, the UL trigger containing uplink scheduling information is sent in the second time interval.

16. The apparatus of claim 15, wherein there is no time gap between the first time interval and the second time interval.

17. The apparatus according to claim 15 or 16, wherein the uplink trigger frame is a MAC frame.

18. The apparatus according to claim 15 or 16, wherein the information I1 is located in L-SIG, repeated L-SIG symbol RL-SIG or HE-SIG-a in the PPDU physical layer frame header.

19. The apparatus according to claim 15 or 16, wherein the PPDU physical layer frame header includes information I2 or information I3 for indicating a location or a length of the UL trigger frame.

20. The apparatus of claim 19, wherein the information I2 is located in HE-SIG-a or HE-SIG-B in a frame header of a physical layer of the PPDU; or

21. The apparatus according to claim 15, 16 or 20, wherein the uplink scheduling information at least includes one or two of the following information: scheduling information for triggering the downlink STA to send ACK; or, the scheduling information is used to trigger the uplink STA to send uplink data.

22. An apparatus for transmitting information, wherein a Wireless Local Area Network (WLAN) includes at least a first time interval and a second time interval after the first time interval within a TXOP;

the apparatus comprises a processing unit configured to: receiving a PPDU physical layer frame header at least before the first time interval, wherein the PPDU physical layer frame header comprises information I1 for indicating whether an uplink trigger frame ULtrigger is in the TXOP memory;

23. The apparatus of claim 22, wherein there is no time gap between the first time interval and the second time interval.

24. The apparatus according to claim 22 or 23, wherein the uplink trigger frame is a MAC frame.

25. The apparatus of claim 22 or 23, wherein the information I1 is located in L-SIG, repeated L-SIG symbol RL-SIG, or HE-SIG-a in a PPDU physical layer frame header.

26. The apparatus of claim 22 or 23, wherein the PPDU physical layer frame header includes information I2 or information I3 for indicating a location or a length of the UL trigger frame.

27. The apparatus of claim 26, wherein the information I2 is located in HE-SIG-a or HE-SIG-B in a frame header of a physical layer of the PPDU; or

28. The apparatus according to claim 22, 23 or 27, wherein the uplink scheduling information at least includes one or two of the following information: scheduling information for triggering the downlink STA to send ACK; or, the scheduling information is used to trigger the uplink STA to send uplink data.