Transmitting and receiving device and method

Abstract

A transmitting device is provided, comprising: circuitry configured to generate a PSDU having at least two Physical Layer (PHY) Service Data Unit (PSDU) portions, and generate a PHY Protocol Data Unit (PPDU) from the PSDU, wherein a first PSDU portion of the PSDU, corresponding to a first number of OFDM symbols, is subjected to a different PHY operation than a second PSDU portion of the PSDU, corresponding to a second number of OFDM symbols, and modulate the PSDU onto a plurality of OFDM symbols included in the PPDU; and transmit the PPDU to at least two receiving devices. Corresponding receiving devices and corresponding methods are also provided.

Description

[Technical Field]

[0001] The present disclosure relates to a transmitting device, a receiving device, a transmitting method, and a receiving method. [Background technology]

[0002] Growing latency-sensitive applications, such as augmented reality (XR) gaming, remote surgery, and smart manufacturing, require delivery of data units within milliseconds or less (also referred to as latency-sensitive data units or preemptive data units) and / or delivery of data units with high reliability (also referred to as reliable data units). Such latency-sensitive data units and reliable data units are collectively referred to herein as high-priority data units.

[0003] In conventional WLAN operation, Media Access Control (MAC) Protocol Data Units (MPDUs) are included into an Aggregated MAC Protocol Data Unit (A-MPDU) by a transmitting device (e.g., a transmitting station (STA) or access point (AP)). All MPDUs within an A-MPDU are modulated using the same modulation operation. At the physical (PHY) layer, the A-MPDUs are embedded into PHY Protocol Data Units (PPDUs) and transmitted from the transmitting device to the receiving device.

[0004] The "Background" discussion provided herein is intended to generally provide a context for the present disclosure. The work of the currently named inventor(s) (to the extent described in the Background section) and aspects of the description that may not be admitted as prior art at the time of filing this application are not admitted, expressly or impliedly, as prior art to the present disclosure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2006 / 120650 [Patent Document 2] US Patent Application Publication No. 2006 / 056443 [Non-patent literature]

[0006] [Non-Patent Document 1] ANWAR SAIF ET AL, "Frame Aggregation in Wireless Networks: Techniques and Issues", IETE TECHNICAL REVIEW.,Vol. {0} 28, No. {0} 4, 01 January 2011(2011-01-01), page 336,XP055261028 [Non-patent document 2] SEONGKWAN KIM ET AL, "MCCA: a high-throughput MAC strategy for next-generation WLANs [medium access control protocols for wireless LANs]", IEEE WIRELESS COMMUNICATIONS, COORDINATED SCIENCE LABORATORY, DEPT. ELECTRICAL AND COMPUTER ENGINEERING, UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN, US,Vol. {0} 15, No. {0} 1, 01 February 2008(2008-02-01), page 32-39,XP011204550 [Non-patent document 3] OTAL B ET AL, "Power Saving Efficiency of a novel Packet Aggregation Scheme for high-throughput WLAN stations at different data rates", 2005 IEEE 61ST VEHICULAR TECHNOLOGY CONFERENCE. VTC2005- SPRING, 30 MAY-1 JUNE 2005, STOCKHOLM, SWEDEN, IEEE, PISCATAWAY, NJ, USA,Vol. {0} 3, 30 May 2005(2005-05-30), page 2041-2045,XP010855785 Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present invention to provide increased flexibility in the transmission of high priority data units, allowing faster and more reliable delivery, as well as corresponding devices and methods, corresponding computer programs, and non-transitory computer-readable recording media storing computer program products for implementing the methods. [Means for solving the problem]

[0008] According to one aspect, there is provided a transmitting device comprising: circuitry configured to generate a PSDU having at least two Physical Layer (PHY) Service Data Unit (PSDU) portions; generate a PHY Protocol Data Unit (PPDU) from the PSDU, wherein a first PSDU portion of the PSDU, corresponding to a first number of OFDM symbols, is subjected to a different PHY operation than a second PSDU portion of the PSDU, corresponding to a second number of OFDM symbols, and modulate the PSDU onto a plurality of OFDM symbols included in the PPDU; and transmit the PPDU to at least two receiving devices.

[0009] According to a further aspect, there is provided a receiving device comprising: circuitry configured to: receive a PHY Protocol Data Unit (PPDU) carrying a PSDU including at least a first PHY Service Data Unit (PSDU) portion and a second PSDU portion, the first PSDU portion being modulated by a PHY operation different from a PHY operation used to modulate the second PSDU portion; determine whether at least one PSDU portion includes data intended for a receiving device; and demodulate the at least one PSDU portion or skip demodulation of the at least one PSDU portion if the at least one PSDU portion does not include data intended for the receiving device or if the receiving device is unable to demodulate in accordance with the corresponding PHY operation used to modulate the at least one PSDU portion.

[0010] According to other further aspects, there are provided corresponding methods, computer programs comprising program means which, when executed on a computer, cause the computer to perform the steps of the methods disclosed herein, and non-transitory computer readable recording media storing a computer program product which, when executed by a processor, causes the computer to perform the methods disclosed herein.

[0011] Each embodiment is defined in a dependent claim. It is understood that the disclosed method, the disclosed computer program and the disclosed computer-readable recording medium have further embodiments similar and / or identical to the claimed device, which are defined in the dependent claims and / or disclosed herein.

[0012] In one aspect of the present disclosure, a mechanism is provided to support different modulation operations (also referred to herein as "PHY modifications" or "PHY operations" or "PHY parameter modifications") for different MPDUs in an A-MPDU, allowing a high priority MPDU to be modulated differently from other MPDUs aggregated in the same A-MPDU and carried in the same PPDU. These different modulation operations preferably occur on an OFDM symbol-by-OFDM symbol basis and preferably do not involve modifications to channel coding operations. Thus, a high priority MPDU can be modulated to provide higher reliability and / or lower delay compared to other MPDUs in the same A-MPDU.

[0013] The foregoing paragraphs have been provided by way of general introduction and are not intended to limit the scope of the claims which follow. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

[0014] The present disclosure and many of the attendant advantages thereof will be readily appreciated as the same becomes better understood by reference to and consideration of the following detailed description, when taken in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0015] [Figure 1] 1 shows a comparison of a conventionally used multi-station A-MPDU and a multi-station A-MPDU used according to an embodiment of the present disclosure. [Figure 2] 1 shows a diagram comparing a conventionally used A-MPDU with an A-MPDU used according to another embodiment of the present disclosure. [Figure 3] 1 illustrates a schematic diagram of an embodiment of a transmitting device according to an embodiment of the present disclosure. [Figure 4] 1 shows a diagram illustrating the general relationship of MAC layer and PHY layer data units. [Figure 5] 1 shows a schematic diagram of a first embodiment of PHY operation modification according to the present disclosure; [Figure 6] 4 shows a flowchart of the operation of a transmitting side STA according to the first embodiment. [Figure 7] 3 shows a flowchart of the operation of a non-PHY-adapting receiving side STA according to the first embodiment. [Figure 8] 10 shows a flowchart of the operation of a PHY adaptive receiving side STA according to the first embodiment. [Figure 9] 1 shows a schematic diagram of a second embodiment of PHY operation modification according to the present disclosure; [Figure 10] 10 shows a schematic diagram of a third embodiment of PHY operation modification according to the present disclosure; [Figure 11] 1 shows a schematic diagram of the A-MPDU and PPDU of the original transmission. [Figure 12] 10 shows a schematic diagram of a fourth embodiment of PHY operation modification according to the present disclosure; [Figure 13] 13 shows a flowchart of the operation of a transmitting side STA according to the fourth embodiment. [Figure 14] 10 shows a schematic diagram of a fifth embodiment of PHY operation modification according to the present disclosure; [Figure 15] 10 shows a flowchart of the operation of a non-PHY adaptive receiving STA according to the fourth embodiment. [Figure 16] 10 shows a flowchart of the operation of a PHY adaptive receiving side STA according to the fourth embodiment. [Figure 17] 10 shows a schematic diagram of another A-MPDU and another PPDU of the original transmission. [Figure 18] 10 shows a schematic diagram of a sixth embodiment of PHY operation modification according to the present disclosure; [Figure 19] 10 shows a schematic diagram of a seventh embodiment of PHY operation modification according to the present disclosure; [Figure 20] 10 shows a flowchart of another embodiment of a transmission method according to the present disclosure. [Figure 21] 10 shows a flowchart of another embodiment of a receiving method according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] Reference is now made to the drawings, wherein like reference numerals refer to the same or corresponding parts throughout the several views. Figures 1 and 2 show diagrams comparing the conventionally used A-MPDU with the A-MPDU used by the present disclosure for two embodiments. These diagrams illustrate how the present disclosure reduces transmission times, particularly for low-latency and reliable communications that are fundamental to supporting growing applications such as virtual reality (VR), smart manufacturing, and remote surgery.

[0017] As shown in Figure 1, the Multi-STA A-MPDU reduces the transmission latency of MPDUs destined for different receiving STAs. For a Multi-STA A-MPDU transmission, a PHY configuration is selected such that all STAs successfully decode the MPDU and the PHY configuration remains fixed for the entire Multi-STA A-MPDU transmission. This is illustrated in Figure 1(a), where the same low PHY data rate is used for all MPDUs.

[0018] Generally, A-MPDU transmission has a fixed PHY configuration. Therefore, for example, when a management frame is added and the frame needs to be transmitted reliably, the overall PHY data rate of the A-MPDU transmission decreases. This is illustrated in Figure 2(a).

[0019] Fixing the PHY data rate for one A-MPDU can result in inefficient transmission, occupying the channel for longer than necessary. A possible solution to this problem is illustrated in FIG. 1(b), which shows a multi-station A-MPDU according to one embodiment of the present disclosure. This allows STA1 to support a high PHY data rate and STA2 to support a lower PHY data rate (e.g., due to poor link quality). Another possible solution to the above problem is illustrated in FIG. 2(b), which shows an A-MPDU according to another embodiment of the present disclosure. This allows MPDU_r (e.g., an important management frame) to require a low PHY data rate, while the remainder of the A-MPDU, i.e., other MPDUs, can be transmitted at a higher PHY data rate.

[0020] 3 shows a schematic diagram of an embodiment of a transmitting device 10 according to an embodiment of the present disclosure. In this disclosure, a distinction is made between the code rate and the PHY data rate. The code rate is the rate between payload bits before and after channel coding, including FEC padding and scrambling performed in the corresponding unit of block 11 (left of box 12). Changes to the code rate of parts of the PPDU can be complex and require extensive signaling.

[0021] Here, the PHY data rate (sometimes referred to as "PHY rate") relates to PHY parameters and / or PHY operations that do not change the code rate, such as changing the operation of the constellation mapper and frequency (or tone) mapping (elements within box 12) that can change the modulation order, the use of dual carrier modulation (DCM), and the use of space-time block coding (STBC). Processing elements or units of transmitting device 10 that may be involved in changing the PHY data rate are shown as box 12.

[0022] In this context, "PHY configuration" should be understood as each operation and parameter related to PHY modification in this disclosure. Enabling or disabling OFDM replication operation, where each OFDM symbol in the OFDM symbol set is replicated at an OFDM replication rate configured to improve reliability; Selection of an OFDM replication rate when OFDM replication operation is enabled; Selection of the modulation order and modulation type used by the constellation mapper to map the coded bits to complex symbols (e.g., BPSK, QPSK, 16-QAM, etc.); Selection of a tone mapping operation that maps complex symbols to subcarriers of an OFDM symbol; Selection of the tone mapping distance and / or cyclic shift used in the tone mapping operation; Enabling or disabling space-time block coding and / or dual carrier modulation to improve robustness to transmitted OFDM symbols; and Selection of guard interval duration for each OFDM symbol to mitigate the effects of delay dispersion may include one or more of:

[0023] PHY parameters should be understood as parameters used to configure the PHY according to a desired PHY configuration. PHY operation should be understood as the steps and functions of using the PHY parameters to modulate coded bits onto OFDM symbols of a PPDU and transmitting the PPDU (i.e., implementing a PHY configuration). A mode of PHY operation should be understood as the particular PHY configuration selected for a particular PPDU transmission.

[0024] This disclosure primarily proposes modifications to the PHY operation that change the PHY data rate within an A-MPDU, i.e., selected MPDU subframes within a PPDU, while leaving the channel coding operation unchanged, i.e., using the same code rate overall. A comparison of known and assumed operations in Figures 1 and 2 illustrates how the assumed operation can reduce the PPDU duration. A PPDU is formed from multiple (i.e., two or more) OFDM symbols transmitted by the PHY, which is a function of the MPDU, from the MAC layer, as shown in Figure 4, for example. Figures 1 and 2 illustrate the benefits of this disclosure, but should not be interpreted as implying that the MPDU is transmitted directly. The actual transmission procedure is described below.

[0025] To support PHY data rate changes, the transmitting and receiving STAs can communicate supported operational capabilities and modes during session setup. In this information exchange, two types of receiving STA operation are defined: non-PHY-adaptive receiving STAs (e.g., legacy STAs) and PHY-adaptive receiving STAs (e.g., STAs according to the present disclosure). The difference between these receiving STAs is that the PHY-adaptive receiving STA is the intended recipient of the MPDU subframe containing the PHY data rate change.

[0026] The information exchanged in such a session setting includes: a session type identifier that can be used to indicate the parameter set and / or mode of operation to use; The type of indication, e.g., a signaling type identifier identifying the A-MPDU containing the PHY data rate change (this can be carried in the PHY preamble or in additional training and signaling OFDM symbols); A mode identifier that identifies the mode of PHY data rate change operation, which may be, for example, OFDM symbol replication and / or OFDM symbol adaptation. It may include one or more elements of:

[0027] Thus, the session type identifier indicates a session in which some PHY operation modifications can be used. The mode identifier indicates a particular PHY operation to be applied to a particular group of one or more PPDUs (among those agreed upon in the session). While OFDM replication is a new and separate operation, OFDM symbol adaptation is the result of modifying other parameters and modes of operation. As a result, more or fewer OFDM symbols may be required compared to the original, which is a result of the modification. Receiving STAs signal their capabilities to the transmitting STA, and the transmitting STA uses the one supported by the receiving STA. The one the transmitting STA uses is specified in the PPDU preamble.

[0028] To implement the PHY data rate change, two main cases of operation can be distinguished. According to the first case (Case 1), the transmitting STA knows that an MPDU subframe will be transmitted with the PHY data rate change before the PHYTXSTART.request is issued. According to the second case (Case 2), the transmitting STA wishes to insert an MPDU subframe with the PHY data rate change after the PHYTXSTART.request is issued. Also, two main modes of operation for changing the PHY data rate can be distinguished. According to the first mode (Mode 1), OFDM symbol replication can be applied, whereby OFDM symbols carrying data from a particular A-MPDU subframe are replicated by a certain amount to improve reliability. According to the second mode (Mode 2), OFDM symbol adaptation can be applied, whereby OFDM symbols carrying data from a particular A-MPDU subframe can include the PHY data rate change. The following describes the operation of a transmitting STA, a non-PHY-adaptive receiving STA, and a PHY-adaptive receiving STA for each case and mode of operation.

[0029] Before describing the above various cases and aspects in detail using various figures and embodiments, the general relationship between data units of the MAC layer and the PHY layer will be explained with reference to Figure 4. Figure 4 particularly illustrates the relationship between MSDU, MPDU, A-MPDU, PSDU and PPDU.

[0030] An MPDU contains one or more MAC Service Data Units (MSDUs). MSDUs arrive from higher layers and are placed in different queues at the MAC layer according to their priority. The Enhanced Distributed Channel Access Function (EDCAF) coordinates channel access for transmitting MSDUs from the queues. One MSDU can be transmitted at a time, or multiple MSDUs can be aggregated to form an aggregated MSDU (A-MSDU). To transmit an MSDU, the MAC layer generates an MPDU by taking an MSDU and adding a MAC header and a Frame Check Sequence (FCS), as shown in Figure 4. The MAC header contains signaling information, including sender and receiver addresses (RAs), duration, frame control, etc., and the FCS corresponds to a sequence used to acknowledge if the MPDU has been correctly received by the receiver.

[0031] An A-MPDU contains a chain of MPDUs packed into subframes, each with a delimiter (DEL) and optional padding (PAD) field. The DEL contains the length of the MPDU within the subframe and a signature that helps identify each subframe at the receiving end. The PAD, on the other hand, is used to ensure that the length of each subframe is a multiple of a predetermined number of bits (e.g., 32).

[0032] When a PHYTXSTART.request indication is sent, the total data length (e.g., in octets) of the A-MPDU is indicated via the TXVECTOR. The A-MPDU is carried by the PHY layer as a PHY Service Data Unit (PSDU). The PSDU is processed by the PHY, including coding and modulation, and the resulting OFDM symbols are transmitted into the wireless medium as part of a PHY Protocol Data Unit (PPDU). The PPDU includes a preamble containing training and signaling fields, and a data field in which the PSDU is carried.

[0033] When PHYTXSTART.request is received by the PHY, the process of transmitting a PPDU begins with the PHY preamble. The PHY sends a PHYTXSTART.confirm indication to the MAC to indicate that it is ready to receive data. The MAC then issues a PHY-Data.request indication to transmit data (e.g., an octet) to the PHY, which then transmits the data (e.g., an octet). Once the PHY receives the data (e.g., an octet), it issues a PHY-Data.confirm to indicate to the MAC that it is ready to receive more data (e.g., another octet). This process continues until the last data (e.g., the last octet) of the PSDU is transmitted. Finally, the MAC issues a PHYTXEND.request to indicate to the PHY that the PSDU transmission is complete. The PHY then terminates the PPDU transmission and issues a PHYTXEND.confirm to the MAC.

[0034] In brief, the PSDU portion is encoded, modulated into a complex symbol, mapped to the subcarriers of an OFDM symbol, and finally, the OFDM symbol is transmitted. The PHY operation involves extracting the PSDU and transmitting it as an OFDM symbol. The PSDU portion is modulated onto the OFDM symbol.

[0035] According to the present disclosure, a PSDU can be divided into several parts, each of which can be processed differently by the PHY layer, resulting in a different number of OFDM symbols depending on the applied PHY operation (e.g., using one or more different PHY parameters or PHY configurations). Each PSDU part can be selected to overlap (or correspond to) a specific MPDU of the A-MPDU, so that each MPDU can be transmitted with a different PHY operation. A PSDU part with PHY modifications can completely overlap an integer number of MPDUs (i.e., correspond to an integer number of MPDUs; see also Figure 10 below) or partially overlap several MPDUs (see also Figures 5 and 9 below). One advantage of overlapping a PSDU part with PHY modifications with at least entire MPDUs intended for different receiving STAs is that it can result in different reliability or delay performance.

[0036] Figure 5 shows a schematic diagram of a first embodiment of PHY operation modification according to the present disclosure. The figure illustrates Case 1, Mode 1, where the PHY data rate modification is known in advance, and OFDM symbol replication is applied for this exemplary embodiment with a replication factor (also referred to herein as the OFDM replication rate) of 2. Figure 5 shows an A-MPDU 20, a PSDU 30, a conventional PPDU 40, and a PPDU 50 according to the present disclosure.

[0037] 6 shows a flowchart of transmitting STA operation 100 according to this embodiment. If a PHY data rate change is to be included in the incoming PPDU, the transmitting side modifies the PPDU length information (e.g., TXTIME) to take into account the repeated OFDM symbols before the MAC circuitry issues a PHYTXSTART.request in step 101. In this case, TXTIME can be modified as follows:

[0038]

number

[0039] During the ceremony, TXTIME non-PHY-change is the TXTIME of the PPDU before considering any PHY data rate changes calculated as per the WLAN standard. The number of OFDM symbols to replicate is N rep (e.g., four in FIG. 5, as shown in PPDU 50 corresponding to PSDU part B of PSDU 30) and f rep is the replication factor (e.g., 2 in Figure 5), and T sym is the time duration of an OFDM symbol including a guard interval or cyclic prefix (CP).

[0040] In step 102, the MAC circuitry indicates the following to the PHY circuitry. This can be done as part of the TXVECTOR or as a separate indication: i) MPDU subframe start and / or end points around the MPDU subframe requiring a PHY data rate change. This can be done by indicating the MPDU subframe of the last octet before and / or containing the PHY data rate change and / or by indicating the DEL of the first octet located at the beginning of and / or after the subframe containing the PHY data rate change. ii) The type of PHY data rate change that is made, in this case OFDM symbol replication, and the associated parameters: replication factor and tone mapping operation for the replicated OFDM symbols.

[0041] In step 103, the PHY circuitry begins PPDU transmission after receiving a PHYTXSTART.request containing the modified PPDU duration and PHY data rate mode of operation.

[0042] In step 104, the transmitting STA indicates information for the receiving STA to specify the PHY data rate change in the PHY preamble (referred to herein as PHY-change-info or PHY operation change signaling). The information can be added explicitly or can use a pre-agreed parameter set indicated using a session identifier. This information includes: RU allocation for A-MPDUs with AID and / or PHY data rate changes for PHY-adapted receiving STAs; Replication factor (i.e., the number of times each OFDM symbol is repeated, e.g., 2 times in Figure 5), OFDM symbol start / end index, and Alternative tone mapping operations for replicated OFDM symbols (symbol interleaver) It includes one or more of the following.

[0043] To find the OFDM symbol start / end indexes, the MAC circuitry can divide the MPDU subframe length by the number of data bits per symbol (NDBPS) to determine how many OFDM symbols are needed per MPDU subframe. Alternatively, the MAC circuitry can exchange signaling with the PHY circuitry before the PPDU begins to obtain this information. The OFDM symbol index at which replication begins can be the OFDM symbol immediately before replication (OFDM symbol 3 in FIG. 5) and / or the first replicated OFDM symbol (OFDM symbol 3-2 in FIG. 5). The OFDM symbol index at which replication ends can be one of the last OFDM symbol being replicated (OFDM symbol 6-2 in FIG. 5), the OFDM symbol immediately before replication (OFDM symbol 7 in FIG. 5), and / or a fixed number of OFDM symbols after the OFDM symbol index that indicates the start of the replication operation.

[0044] In the conventional PPDU 40, no OFDM symbols are replicated, but in step 105 the PHY circuitry replicates the OFDM symbols of PSDU part B starting from the symbol where the MPDU subframe for the PHY-adaptive receiving STA begins. Optionally, an alternative tone mapping operation may be additionally performed that is different from the original OFDM symbols and different between the replicated OFDM symbols. The alternative tone mapping operation may be performed using a tone spacing parameter (D TM ) and / or by a fixed cyclic shift relative to the previous tone mapping. If the non-PHY-adapted receiving STA is a legacy STA, it cannot add MPDU subframes addressed to that STA after the PHY data rate change. The other PSDU parts A and C are not replicated as shown for PPDU 50.

[0045] FIG. 7 shows a flowchart of non-PHY-adaptive receiving STA operation 200 according to this embodiment. In a first step 201, an indication in the PHY preamble is received to obtain PHY change information. In a second step 202, OFDM symbols in the data field are processed normally until the last OFDM symbol before OFDM symbol replication begins (e.g., symbol 3 in FIG. 5). In step 203, reception of the subframe after the PHY change is resumed, maintaining OFDM symbol synchronization and codeword (CW) alignment. This can be done by selecting only the first OFDM symbol of each replicated group (e.g., symbol 4-1, symbol 5-1, and symbol 6-1 in FIG. 5) within the symbol replication and / or by processing the CW normally or by tracking the end / beginning of the CW after constellation demapping. To save power, the receiver may choose not to decode the CWs of the OFDM symbols in the replication (e.g., the CWs in symbols 4-2 and 5-2 in FIG. 5). After all replication symbols have been sent, the STA may resume normal receiver operation in step 204. If the STA is a legacy STA, it processes the A-MPDU normally and can only decode the first MPDU subframe before the OFDM symbol replication.

[0046] FIG. 8 shows a flowchart of PHY-adaptive receiving STA operation 300 according to this embodiment. In a first step 301, an indication in the PHY preamble to obtain PHY modification information is received. In a second step 302, the OFDM symbols in the data field are processed normally until the last OFDM symbol before OFDM symbol replication begins (e.g., symbol 3 in FIG. 5). If no DEL is specified or the FCS is incorrect, as determined in step 303, OFDM symbol processing continues in step 304 to maintain synchronization and CW alignment. Within symbol replication, in step 305, the STA combines replicated symbols, for example, by adding LLR values ​​extracted from the data symbols of the data subcarriers in each replicated OFDM symbol to a tone demapping operation. Once all replications of a given symbol have been combined, the decoding process continues.

[0047] If a DEL is found in step 303, if the FCS is verified to be correct, and if the recipient address in the MAC header corresponds to a PHY-adapted receiving STA, the MSDU is sent to higher layers in step 306. The STA generates a feedback indication in step 307 and can send the feedback indication in a separate frame to indicate to the transmitting STA the success or failure of the PHY data rate change.

[0048] After all replication symbols have been sent, the STA may continue processing the PPDU in step 308 if further PHY data rate changes are indicated. Otherwise, the STA may stop decoding to save energy and set its NAV accordingly. If several separate PHY changes are included in a PPDU transmission, one of the following mechanisms to reduce signaling overhead may be used: group subframes with equal PHY changes and transmit them consecutively, with the first and last OFDM symbol information carried once for the entire group; or move at least part of the PHY change information to a MAC signaling field present at the beginning of the A-MPDU.

[0049] FIG. 9 shows a schematic diagram of a second embodiment of a PHY operation modification according to the present disclosure. This diagram illustrates Mode 2 for Case 1, where the PHY data rate modification is known in advance, and OFDM symbol adaptation is applied. According to this exemplary embodiment, three additional OFDM symbols are added, as shown for PPDU 51 compared to conventional PPDU 40, to improve the reliability of the MPDU subframe and PSDU portion B for the PHY-adaptive receiving STA. The PHY data rate modification can be performed on an integer number of OFDM symbols. Thus, PSDU portion B with conventional PHY operation is modulated onto three OFDM symbols (e.g., OFDM symbols 3-5 in PPDU 40). In contrast, with the PHY operation modification, PSDU portion B is modulated onto six OFDM symbols (e.g., OFDM symbols 3-8 in PPDU 51). This can be achieved, for example, by reducing the modulation order from four (16-QAM) to two (QPSK).

[0050] First, the operation on the transmitting side will be described. Similar to step 101 of the first embodiment described with reference to Figure 5, TXTIME can be modified as follows:

[0051]

number

[0052] In the formula, N adapt is added to the original transmission time (or N adapt is the number of OFDM symbols to be added (subtracted if negative). This number of OFDM symbols can be calculated as follows:

[0053]

number

[0054] In the formula, N rep N represents the number of OFDM symbols for which a PHY change is required (e.g., 3 in FIG. 9). DBPS / N DBPS-adapt indicates whether the PHY data rate change adds OFDM symbols (i.e., is greater than 1) or subtracts OFDM symbols (i.e., is less than 1), where N DBPS is the number of data bits per OFDM symbol without PHY data rate modification, and N DBPS-adapt is the number of data bits per OFDM symbol with PHY data rate change.

[0055] Due to the sealing operation in equation (1), it may be necessary to add PHY padding to the last OFDM symbol. Figure 10 shows a schematic diagram of a third embodiment of the PHY operation modification according to the present disclosure, which uses aggregation, fragmentation, and padding to align the start / end of the MPDU subframe around the PHY modification. In another embodiment, only one or two of aggregation, fragmentation, and padding may be used. The PHY padding may include a fixed, pre-agreed complex symbol or data symbol repetition. An A-MPDU 22 including aggregation and fragmentation and a PPDU 52 including PHY padding are shown in Figure 10.

[0056] Next, similar to step 102 in the first embodiment, the MAC circuitry indicates the following to the PHY circuitry: i) The start / end of the MPDU subframe around the PHY data rate change, ii) The type of PHY data rate change, including one or more of the following: Changes to the modulation format of the constellation mapper (e.g., from 16-QAM to QPSK), and Enable or disable the use of DCM and / or STBC.

[0057] Since the PHY data rate change is per OFDM symbol, the end of the subframe preceding the PHY change may be included in the OFDM symbol with the PHY change, as shown in Figure 9. To support legacy operation or to simplify PHY operation at a non-PHY adaptive receiver, the transmitter may start the subframe with the PHY change in a separate OFDM symbol. Thus, the transmitter may perform one or more of the following actions (as shown in Figure 10) (depending on the minimum MPDU start interval, this may not be necessary): Aggregation and / or fragmentation of MSDUs (including, for example, MSDU1 in FIG. 10) in the subframe preceding the PHY change; Aggregation of MSDUs (including, for example, MSDUp1 in Figure 10) within a subframe with PHY changes; Padding using DEL before and after MPDU subframes transmitted by PHY change, and PHY padding to fill out OFDM symbols before the PHY change, terminating the PHY change and / or the last OFDM symbol.

[0058] Subsequently, similar to step 103, the STA starts transmitting a PPDU with the length and PHY change. In a next step (such as step 104), the transmitter indicates PHY change information in the PHY preamble. The PHY change information includes the type of PHY data rate change and / or the OFDM symbol index at which the PHY data rate change starts and / or ends and / or their duration. In a subsequent step, the PHY circuitry applies the PHY data rate change to the OFDM symbol containing the beginning of the MPDU subframe requiring the PHY change, up to the OFDM symbol containing the end of that subframe. Then, the PHY operation reverts to the original operation. When operating as a legacy STA, after the PHY data rate change, no MPDU subframes addressed to the STA can be added.

[0059] Next, the operation of a non-PHY-adapted receiving STA will be described for the second and third embodiments. First, PHY change information is obtained by performing step 201. Then, similar to step 202, OFDM symbols are processed up to the OFDM symbol before the symbol containing the PHY change (e.g., symbol 2 in FIG. 9). For the OFDM symbol containing the start of the PHY change, OFDM demodulation is performed and frequency demapping and / or constellation demapping is modified to extract the data symbols with the PHY change. Then, similar to step 203, OFDM symbol synchronization and CW alignment are maintained. This can be done by continuing to process the modified OFDM symbols up to the last OFDM symbol containing the PHY change and / or by OFDM symbol demodulation and performing frequency and constellation demapping. To save power, the device can stop decoding CWs mapped to the PHY change while keeping track of the transition points between CWs (i.e., when each CW starts / ends) to maintain codeword alignment.

[0060] For the last OFDM symbol before and / or including the PHY change (e.g., symbol 3 or 8 in FIG. 10), discard or process PHY padding, if any. If the PHY padding includes data symbol repetition, the receiver can combine the LLR values ​​of the padded data symbols with the LLR values ​​of their corresponding original data symbols to improve reliability. Then, similar to step 204, perform OFDM symbol processing as usual after the PHY change. Finally, if the STA is a legacy STA, it processes the A-MPDU as usual and can only decode the first MPDU subframe before the OFDM symbol including the PHY change.

[0061] Next, the PHY-adaptive receiving STA operation will be described for the second and third embodiments. First, execute step 301 to obtain PHY change information. Then, even if decoding fails, process OFDM symbols up to the OFDM symbol before the PHY change (e.g., symbol 2 in FIG. 9) as in steps 302-304. Next, process the OFDM symbol containing the start of the PHY change accordingly as in step 305, and continue OFDM symbol processing up to the last OFDM symbol containing the PHY change. Next, discard or process PHY padding, if any, for the last OFDM symbol before and / or containing the PHY change, as described above for non-PHY-adaptive receiving STA operation. If the PHY padding includes data symbol repetition, the receiving side can combine the LLR values ​​of the padded data symbols with the LLR values ​​of their corresponding original data symbols to improve reliability. Next, steps 306-308 may be performed.

[0062] In the above first, second, and third embodiments, different modes are described for Case 1, where the PHY data rate change is known in advance. Below, each embodiment will be described for Case 2, where the PHY data rate change is not known in advance.

[0063] FIG. 11 shows a schematic diagram of an A-MPDU 23 and a PPDU 43 of an original transmission. FIG. 12 shows a schematic diagram of a fourth embodiment of a PHY operation change according to the present disclosure. This diagram illustrates Mode 1 for Case 2, where the PHY data rate change is not known in advance and OFDM symbol replication is applied. According to this embodiment, an indication to insert MSDUp1 arrives after a PHYTXSTART.request. Therefore, the PPDU length is already set, and the A-MPDU contents can be adapted to enable the PHY data rate change within the set PPDU length. FIG. 12 shows an A-MPDU 24, a PPDU 44 obtained using a PHY configuration with a fixed PHY data rate, and a PPDU 54 obtained using a PHY configuration with a PHY data rate that changes with OFDM symbol replication. This exemplary embodiment uses a symbol replication factor of 2.

[0064] 13 shows a flowchart of the transmitting STA operation 400 according to this embodiment. In step 401, the receiving STA is informed that a particular PPDU may contain a PHY data rate change. This can be indicated in the PHY preamble or in a separate frame. In step 402, it is checked whether the MSDU requiring a PHY data rate change (e.g., MSDUp1 in FIG. 12) can be transmitted after the transmission of the current MPDU subframe without exceeding the configured transmission time (e.g., TXTIME). This check is performed by the following conditions:

[0065]

number

[0066] In the formula, N sym-bef-PHYchg is the number of OFDM symbols before replication (e.g., 3 in Fig. 12), and N TI is the number of symbols used for training and signaling. If the above condition is met, MSDUp1 can be transmitted, otherwise it cannot be transmitted.

[0067] In step 403, operations corresponding to step 102 (shown in FIG. 6) are performed to indicate each transition point between MPDU subframes and the type of PHY data rate change. Then, in step 404, training and signaling symbols are inserted after the OFDM symbol before the PHY change (e.g., symbol 3 in FIG. 12) to indicate to the receiving STA that an unscheduled PHY data rate change is occurring (OFDM replication in this embodiment) along with the PHY change information. This can be included explicitly, identified by a session identifier, or explicitly included in a specific type of training field. This type of training field can be generated by using LTF as part of the midamble in the PPDU data field. To include the implicit indication in the midamble, the following modifications can be applied: multiplying selected tones (possibly all) in the LTF sequence by a specific phase shift (e.g., −1) and / or modifying the mapping operation to invert this specific phase shift in the selected tones when transmitting the subsequent data field. As an example, if the initial shift is -1, the spatial streams are multiplied by -1 through mapping. Optionally, for the receiving STA, training symbols may be used to improve channel estimation quality. If implicit indication is used in the midamble and training symbols in the preamble are used, the receiver may consider the phase shift within the selected tones.

[0068] Subsequently, in step 405, OFDM symbol replication is performed after the training and signaling symbols by performing the operations of step 105. As shown in Figure 12, if the remaining TXTIME is too short to add additional subframes, the MAC circuitry does not insert the next subframe and / or inserts an End of Frame (EOF) indication after the subframe with the PHY change in step 405. If necessary, the PHY circuitry may add padding to the last replicated OFDM symbol in step 406.

[0069] If there is sufficient TXTIME to add an additional MPDU subframe, the MAC circuitry may perform MSDU aggregation / fragmentation and / or DEL padding to fill as much of the remaining TXTIME as possible. If necessary, the PHY circuitry may add PHY padding to the last OFDM symbol. This is illustrated in FIG. 14, which shows a schematic diagram of a fifth embodiment of PHY operation modification according to the present disclosure. FIG. 14 shows an A-MPDU 25, a PPDU 45 obtained using a PHY configuration with a fixed PHY data rate, and a PPDU 55 obtained using a PHY configuration with a varying PHY data rate via OFDM symbol replication. Here, an additional OFDM symbol has been added to the end of PPDU 55 after the OFDM symbol of the MPDU subframe with the PHY modification. Therefore, the MPDU subframe with the PHY modification after insertion is not the last MPDU subframe in PPDU 55. Finally, the legacy STA behavior operations described above may be performed.

[0070] FIG. 15 shows a flowchart of the operation 500 of a non-PHY-adaptive receiving STA according to this embodiment. In step 501, the OFDM symbols of the PPDU are processed normally until the training and signaling symbols are found. In step 502, PHY modification information is obtained based on the indication in the training and signaling symbols. If enabled, the training and signaling symbols can be used to improve the channel estimate. If Midamble is used as an implicit indication, the receiving STA calculates a channel estimate based on Midamble and compares it with the previous channel estimate (e.g., multiplying the complex conjugate of the new and previous channel estimates tone by tone). The indication can be extracted from a specific (e.g., pre-agreed) phase shift detected in such a comparison. The updated channel estimate may be used to continue processing subsequent data fields.

[0071] In step 503, the operations of step 203 are performed after training and signaling symbols (OFDM synchronization and CW alignment). In step 504, the operations of step 204 are performed (continue processing OFDM symbols, if any). Finally, the legacy STA behavior operations described above may be performed.

[0072] FIG. 16 shows a flowchart of PHY-adaptive receiving STA operation 600 according to this embodiment. In step 601, an indication is received from the transmitting STA identifying which particular PPDU contains a PHY data rate change. If no such indication is present, the STA can process each PPDU normally until it finds a training and signaling symbol. In step 602, the operations of steps 302-304 are performed (processing OFDM symbols up to the training / signaling symbol). In step 603, the operations of step 502 are performed (obtaining PHY change information). In step 604, the operations of step 305 are performed (combining replicated OFDM symbols). In step 605, the operations of steps 306-308 may be performed, i.e., the receiving STA may send an MSDU to higher layers, optionally generate a feedback indication, and continue processing OFDM symbols if more PHY changes are indicated in the training and signaling symbols.

[0073] FIG. 17 shows a schematic diagram of another A-MPDU 26 and another PPDU 46 of the original transmission. FIG. 18 shows a schematic diagram of a sixth embodiment of PHY operation modification according to the present disclosure. This figure illustrates Mode 2 for Case 2, where the PHY data rate modification is not known a priori, and OFDM symbol adaptation is applied. FIG. 18 shows A-MPDU 27 and PPDU 57 obtained using a PHY configuration in which the PHY data rate is changed by adding an OFDM symbol. According to this embodiment, an additional OFDM symbol is added to improve the reliability of the MPDU subframe carrying MSDUp1. The PHY data rate modification is performed for an integer number of OFDM symbols.

[0074] First, the operation of the transmitting STA for the sixth embodiment will be described. First, the operation of step 401 is performed (indication of a PPDU with a possible PHY change). Then, similar to step 402, it checks whether the inserted MSDU fits into the remaining TXTIME. This check is performed based on the following conditions:

[0075]

number

[0076] In the formula, N adapt is obtained by equation (1). (N adapt If PHY padding is required (due to a ceiling operation in the calculation), it can be added to the last OFDM symbol.

[0077] The MAC circuitry then provides an indication of the transition between MPDU subframes and the type of PHY data rate change to the PHY circuitry, as described above for Mode 2 of Case 1, and performs aggregation, fragmentation, and / or padding to align the MPDU subframes with the PHY change to the beginning and / or end within separate OFDM symbols. If necessary, PHY padding is added to the OFDM symbol before the PHY change (e.g., symbol 3 in Figure 18). This ensures that the MPDU subframe with the PHY change is transmitted in the OFDM symbol after the training and signaling symbols.

[0078] Next, the operation of step 404 is performed, inserting training and signaling symbols after the last OFDM symbol without a PHY modification (e.g., after symbol 3 in FIG. 18). The PHY modification is applied after the training and signaling symbols. As shown in FIG. 18, if the remaining TX TIME is too short, the MAC circuitry does not insert another subframe and / or inserts an EOF, and the PHY circuitry adds PHY padding to the last OFDM symbol, if necessary. Alternatively, if TX TIME allows, an MPDU subframe is added. This is illustrated in FIG. 19, which shows a schematic diagram of a seventh embodiment of PHY operation modification according to the present disclosure. FIG. 19 shows an A-MPDU 28 and a PPDU 58 obtained using a PHY configuration with a PHY data rate that changes with the addition of an OFDM symbol. An additional OFDM symbol is added to the end of the PPDU 58 after the OFDM symbol of the MPDU subframe that uses the PHY modification. Therefore, the MPDU subframe with the PHY change after insertion is not the last MPDU subframe in the PPDU 58. Finally, the legacy STA behavior operations described above may be performed.

[0079] Next, the operation of a non-PHY-adapted receiving STA will be described for the sixth embodiment. First, the operation of step 501 is performed, i.e., normal operation is performed, until training and signaling symbols are found. Then, the operation of step 502 is performed, i.e., PHY modification information is obtained. After the training and signaling symbols, OFDM demodulation is performed, and frequency demapping and / or constellation demapping are modified to apply the PHY modification. Subsequently, the operation of step 503 (OFDM symbol synchronization and CW alignment) and PHY padding may be discarded or processed as described above for Mode 2 of Case 1. Then, the operation of step 504 is performed (continue processing OFDM symbols, if any). Finally, the legacy STA processing described above may be performed.

[0080] Next, the operation of the PHY-adaptive receiving STA will be described for the sixth embodiment. First, the process of step 601 (indication of whether the PPDU may contain a PHY change), step 602 (processing OFDM symbols even if decoding fails), and step 603 (obtaining PHY change information) is performed. Then, the OFDM symbols with the PHY change are processed. The last OFDM symbol before and / or including the PHY change is executed, and PHY padding, if any, is discarded or processed. Then, as in step 306, if the packet is received correctly, it is sent to a higher layer. Finally, as in step 308, if there is a further PHY change, processing of the OFDM symbols continues.

[0081] 20 shows a flowchart of another embodiment of a transmission method 700 according to the present disclosure. In a first step 701, a PSDU including at least two PSDU portions is generated. In a second step 702, a PPDU is generated from the PSDU, including modulating the PSDU onto a plurality of OFDM symbols included in the PPDU. In addition, a first PSDU portion of the PSDU corresponding to a first number of OFDM symbols undergoes a different PHY operation than a second PSDU portion of the PSDU corresponding to a second number of OFDM symbols. In a third step 703, the PPDU is transmitted to at least two receiving devices.

[0082] 21 shows a flowchart of a receiving method 800 according to another embodiment of the present disclosure. In a first step 801, a PPDU carrying a PSDU including at least a first PSDU portion and a second PSDU portion is received. In a second step 802, it is determined whether the at least one PSDU portion contains data addressed to a receiving device. In a third step 803, the at least one PSDU portion is demodulated. Alternatively, if the PSDU does not contain data addressed to the receiving device or if the receiving device is unable to perform demodulation according to the corresponding PHY operation used to modulate the at least one PSDU portion, demodulation of the at least one PSDU portion is skipped.

[0083] In summary, this disclosure focuses on link adaptation for transmitting A-MPDUs. MPDUs aggregated in an A-MPDU may have different reliability or delay requirements. While these are conventionally transmitted using the same PHY configuration, this disclosure presents a mechanism to support different PHY data rates for different MPDUs in an A-MPDU. The PHY change is performed on an OFDM symbol-by-OFDM symbol basis and does not involve modifications to channel coding operations.

[0084] Accordingly, the foregoing discussion discloses and describes merely exemplary embodiments of the present disclosure. As will be understood by those skilled in the art, the present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. The disclosure of the present disclosure, as well as the remaining claims, is hereby intended to be illustrative and not limiting of the scope of the present disclosure. The present disclosure defines in part the scope of the preceding claim terms, including readily discernible variations of the teachings herein, so that the inventive subject matter is not dedicated to the public.

[0085] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0086] To the extent that embodiments of the present disclosure have been described as being implemented, at least in part, by software-controlled data processing apparatus, it will be understood that non-transitory machine-readable media bearing such software, such as, for example, optical disks, magnetic disks, semiconductor memories, etc. Furthermore, such software may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

[0087] The elements of the disclosed devices, apparatus, and systems may be implemented by corresponding hardware and / or software elements, such as appropriate circuits or circuit portions. A circuit is a structural collection of electronic components, including conventional circuit elements, integrated circuits including application-specific integrated circuits, standard integrated circuits, application-specific standard products, and field-programmable gate arrays. A circuit also includes a central processing unit, a graphics processing unit, and a microprocessor that are programmed or configured according to software code. A circuit includes the above-mentioned hardware that executes software, but does not include pure software. A circuit or circuit portion may be implemented by a single device or unit, or by multiple devices or units, or by chipset(s), or by processor(s).

[0088] Below is a list of further embodiments of the disclosed subject matter. (1) generating a PSDU having at least two PHY (Physical Layer) Service Data Unit (PSDU) portions; generating a PHY Protocol Data Unit (PPDU) from the PSDU, wherein a first PSDU portion of the PSDU corresponding to a first number of OFDM symbols is subjected to a different PHY operation than a second PSDU portion of the PSDU corresponding to a second number of OFDM symbols, including modulating the PSDU onto a plurality of OFDM symbols included in the PPDU; transmitting said PPDU to at least two receiving devices; A circuit section configured as follows: Equipped with Sending device. (2) The transmitting device according to embodiment 1, the circuitry is configured to generate the PSDU from an aggregated MAC protocol data unit (A-MPDU) having one or more first media access control (MAC) protocol data units (MPDUs) and one or more second MPDUs; The first PSDU portion of the PSDU overlaps or corresponds to one or more first MPDUs, and the second PSDU portion of the PSDU overlaps or corresponds to one or more second MPDUs. Sending device. (3) The transmitting device according to embodiment 2, The one or more first MPDUs are destined for a different receiving device than the one or more second MPDUs. Sending device. (4) The transmitting device according to embodiment 2 or 3, The circuitry is configured to select, as the one or more first MPDUs, priority MPDUs having higher reliability and / or lower delay requirements than the one or more second MPDUs. Sending device. (5) The transmitting device of any one of the preceding embodiments, The circuitry is configured to use at least one PHY operation to modulate the first PSDU portion of the PSDU that is different from a PHY operation used to modulate the second PSDU portion of the PSDU. Sending device. (6) The transmitting device according to any one of the preceding embodiments, The circuit unit includes: Enable or disable OFDM symbol replication, Changing the OFDM symbol replication rate, Change the modulation order, Constellation mapping changes, Tone mapping changes, Enable or disable dual carrier modulation, Enabling or disabling space-time block coding, and Changing the guard interval and configured to apply one or more of the PHY operation modifications to differently modulate the first PSDU portion and / or the second PSDU portion, including Sending device. (7) The transmitting device according to any one of the preceding embodiments, The circuitry is configured to apply a more robust constellation and / or a different tone mapping to modulate the first PSDU portion. Sending device. (8) The transmitting device according to any one of the preceding embodiments, 2. A transmitting device according to claim 1, the circuitry is configured to apply OFDM symbol replication to modulate the first PSDU portion; Applying different tone mappings to first OFDM symbols corresponding to the respective replicated first PSDU portions. Sending device. (9) The transmitting device according to any one of the preceding embodiments, The circuitry is configured to initialize a session to exchange information with two or more receiving devices regarding their respective capabilities and / or modes of PHY operation. Sending device. (10) The transmitting device according to embodiment 9, The circuitry is configured to use only modes of PHY operation supported by all receiving devices for the first and second PSDU portions. Sending device. (11) The transmitting device according to embodiment 9 or 10, The circuit unit includes, as information regarding the PHY operation mode: a session type identifier indicating a set of one or more PHY operations used to modulate the first PSDU portion; A signaling type identifier indicating how to signal different PHY operations for any PSDU portion; and a mode identifier indicating one or more PHY operations that can be used to modulate the first PSDU portion; configured to replace one or more of Sending device. (12) The transmitting device of any one of the preceding embodiments, The circuit unit includes: if an indication to apply a different PHY operation to the first PSDU part is obtained before a PPDU transmission start request is issued, calculate the PPDU length and include PPDU length information in the PPDU indicating the calculated PPDU length; or If an indication to apply a different PHY operation to the first PSDU portion is obtained after a PPDU transmission start request is issued, the PPDU length of the PPDU is maintained. It is configured as follows: Sending device. (13) The transmitting device according to embodiment 12, The circuitry is configured to determine whether a time duration of the first number of OFDM symbols corresponding to the first PSDU portion is shorter or longer than the PPDU length minus a margin accounting for a time duration of the second number of OFDM symbols, a preamble period, a training field period, and / or one or more additional training or signaling OFDM symbols included in the PPDU. Sending device. (14) The transmitting device according to any one of the preceding embodiments, The circuitry controls the PHY operation changes used to modulate the first PSDU portion and / or the second PSDU portion, a preamble of the PPDU; The signaling field present at the beginning of each PSDU, and one or more additional training or signaling OFDM symbols included in the PPDU and configured to signal to the at least two receiving devices at one of Sending device. (15) The transmitting device of any one of the preceding embodiments, the circuitry is configured to encode each PSDU prior to modulation; The code rate used for encoding the first PSDU portion is the same as the code rate used for encoding the second PSDU portion. Sending device. (16) The transmitting device of any one of the preceding embodiments, The circuitry applies one or more of aggregation, fragmentation, and padding to the one or more first MPDUs and / or the one or more second MPDUs, and / or adds padding to the A-MPDUs to align corresponding portions of the first and / or second PSDUs with respect to boundaries between OFDM symbols. configured to Sending device. (17) The transmitting device of any one of the preceding embodiments, The circuitry is configured to completely or partially remove the first and / or second PSDU portions if the time period of the first number of OFDM symbols is longer than the PPDU length minus the margin. Sending device. (18) The transmitting device of any one of the preceding embodiments, The circuitry is configured to include the second PSDU portion before the first PSDU portion if the different PHY operation applied to the first PSDU portion is not supported by the intended receiving device of the second PSDU portion. Sending device. (19) receiving a PHY Protocol Data Unit (PPDU) carrying a PSDU including at least a first PHY Service Data Unit (PSDU) portion and a second PSDU portion, the first PSDU portion being modulated by a PHY operation different from a PHY operation used to modulate the second PSDU portion; determining whether at least one PSDU portion contains data intended for a receiving device; demodulating the at least one PSDU portion or skipping demodulation of the at least one PSDU portion if the PSDU does not contain data intended for the receiving device or if the receiving device is unable to demodulate the at least one PSDU portion in accordance with the corresponding PHY operation used to modulate the at least one PSDU portion; A circuit section configured as follows: Equipped with Receiving device. (20) A receiving device according to embodiment 19, The circuit unit includes: deriving an Aggregated Media Access Control (MAC) Protocol Data Unit (A-MPDU) from the PSDU carried by the received PPDU, the A-MPDU including one or more first MAC Protocol Data Units (MPDUs) and one or more second MPDUs, the first PSDU portions of the received PSDU overlapping or corresponding to one or more first MPDUs and the second PSDU portions overlapping or corresponding to one or more second MPDUs; demodulating the first PSDU portion if the first MPDU is addressed to the receiving device, and / or demodulating the second PSDU portion if the second MPDU is addressed to the receiving device; It is configured as follows: Receiving device. (21) The receiving device according to embodiment 19 or 20, The circuitry demodulates the second and / or further PSDU portions if they contain data intended for the receiving device. It is configured as follows: Receiving device. (22) The receiving device according to any one of the embodiments 19 to 21, The circuit unit includes: a preamble of the PPDU; The signaling field present at the beginning of each PSDU, and one or more additional training or signaling OFDM symbols included in the PPDU deriving PHY operation change signaling indicating modulation of the first PSDU portion and / or the second PSDU portion by a transmitting device from one of the It is configured as follows: Receiving device. (23) The receiving device according to any one of the embodiments 19 to 22, The circuitry maintains OFDM symbol synchronization and / or codeword alignment when demodulation of the first PSDU portion is skipped. Receiving device. (24) generating at least two PHY (Physical Layer) service data units (PSDUs); generating a PHY Protocol Data Unit (PPDU) from the PSDU, the PHY Protocol Data Unit including modulating the PSDU onto a plurality of OFDM symbols included in the PPDU, wherein a first PSDU portion of the PSDU corresponding to a first number of OFDM symbols undergoes a different PHY operation than a second PSDU portion of the PSDU corresponding to a second number of OFDM symbols; transmitting said PPDU to at least two receiving devices; Sending method. (25) receiving a PHY Protocol Data Unit (PPDU) carrying a PSDU including at least a first PHY Service Data Unit (PSDU) portion and a second PSDU portion, the first PSDU portion being modulated by a PHY operation different from a PHY operation used to modulate the second PSDU portion; determining whether at least one PSDU portion contains data intended for a receiving device; demodulating the at least one PSDU portion or skipping demodulation of the at least one PSDU portion if the PSDU does not contain data intended for the receiving device or if the receiving device is unable to demodulate the at least one PSDU portion in accordance with the corresponding PHY operation used to modulate the at least one PSDU portion; Receiving method. (26) A non-transitory computer-readable recording medium storing a computer program product that, when executed by a processor, causes the method according to embodiment 24 or 25 to be performed. (27) A computer program comprising program code means which, when executed on a computer, causes the computer to perform the steps of the method according to embodiment 24 or 25.

Claims

1. generating a physical layer (PHY) service data unit (PSDU) having at least two PHY service data unit (PSDU) portions; generating a PHY Protocol Data Unit (PPDU) from the PSDU, wherein a first PSDU portion of the PSDU corresponding to a first number of OFDM symbols undergoes a different PHY operation than a second PSDU portion of the PSDU corresponding to a second number of OFDM symbols, including modulating the PSDU onto a plurality of OFDM symbols included in the PPDU; Transmitting the PPDU to at least two receiving devices. A circuit section configured as follows: Equipped with Sending device.

2. 2. The transmitting device of claim 1, the circuitry is configured to generate the PSDU from an aggregated MAC protocol data unit (A-MPDU) having one or more first media access control (MAC) protocol data units (MPDUs) and one or more second MPDUs; the first PSDU portion of the PSDU overlaps or corresponds to one or more first MPDUs, and the second PSDU portion of the PSDU overlaps or corresponds to one or more second MPDUs; In particular, the one or more first MPDUs are destined for a different receiving device than the one or more second MPDUs. Sending device.

3. 3. A transmitting device according to claim 2, The circuitry is configured to select, as the one or more first MPDUs, priority MPDUs having higher reliability and / or lower delay requirements than the one or more second MPDUs. Sending device.

4. 2. The transmitting device of claim 1, The circuit unit includes: Enabling or disabling OFDM symbol replication; Changing the OFDM symbol replication rate; Change the modulation order, Constellation mapping changes, Tone mapping changes, Enable or disable dual carrier modulation, Enabling or disabling space-time block coding, and Changing the guard interval and applying one or more PHY operation modifications to differentially modulate the first PSDU portion and / or the second PSDU portion, including Sending device.

5. 2. The transmitting device of claim 1, the circuitry is configured to apply OFDM symbol replication to modulate the first PSDU portion; applying different tone mappings to first OFDM symbols corresponding to the respective replicated first PSDU portions; Sending device.

6. 2. The transmitting device of claim 1, The circuitry is configured to exchange information with two or more receiving devices regarding their respective capabilities and / or modes of PHY operation, and in particular to initialize a session to use only modes of PHY operation supported by all receiving devices for the first and second PSDU portions. Sending device.

7. 7. A transmitting device according to claim 6, The circuit unit may include, as information regarding a PHY operation mode: a session type identifier indicating a set of one or more PHY operations used to modulate the first PSDU portion; A signaling type identifier indicating how to signal which PSDU portion to perform different PHY operations; and a mode identifier indicating one or more PHY operations that may be used to modulate the first PSDU portion; configured to replace one or more of Sending device.

8. 2. The transmitting device of claim 1, The circuit unit includes: If an indication to apply a different PHY operation to the first PSDU part is obtained before a PPDU transmission start request is issued, calculate the PPDU length and include PPDU length information indicating the calculated PPDU length in the PPDU; or If an indication to apply a different PHY operation to the first PSDU portion is obtained after a PPDU transmission start request is issued, the PPDU length of the PPDU is maintained. It is configured as follows: Sending device.

9. 9. A transmitting device according to claim 8, The circuitry is configured to determine whether a time duration of the first number of OFDM symbols corresponding to the first PSDU portion is shorter or longer than the PPDU length minus a margin accounting for a time duration of the second number of OFDM symbols, and / or a preamble period, and / or a training field period, and / or one or more additional training or signaling OFDM symbols included in the PPDU; and / or to completely or partially remove the first and / or second PSDU portion if the time duration of the first number of OFDM symbols is longer than the PPDU length minus the margin. Sending device.

10. 2. The transmitting device of claim 1, The circuitry controls the PHY operation modifications used to modulate the first PSDU portion and / or the second PSDU portion, a preamble of the PPDU; a signaling field present at the beginning of each PSDU part, and one or more additional training or signaling OFDM symbols included in the PPDU configured to signal to the at least two receiving devices at one of Sending device.

11. 2. The transmitting device of claim 1, the circuitry is configured to encode each PSDU prior to modulation; The code rate used to encode the first PSDU portion is the same as the code rate used to encode the second PSDU portion. Sending device.

12. 2. The transmitting device of claim 1, The circuitry applies one or more of aggregation, fragmentation, and padding to the one or more first MPDUs and / or the one or more second MPDUs, and / or adds padding to the A-MPDUs to align corresponding portions of the first and / or second PSDUs with respect to boundaries between OFDM symbols. configured to Sending device.

13. 2. The transmitting device of claim 1, The circuitry is configured to include the second PSDU portion before the first PSDU portion if the different PHY operation applied to the first PSDU portion is not supported by the intended receiving device of the second PSDU portion. Sending device.

14. receiving a PHY Protocol Data Unit (PPDU) carrying a PSDU including at least a first PHY Service Data Unit (PSDU) portion and a second PSDU portion, the first PSDU portion being modulated by a PHY operation that is different from a PHY operation used to modulate the second PSDU portion; determining whether at least one PSDU portion contains data intended for a receiving device; demodulating the at least one PSDU portion or skipping demodulation of the at least one PSDU portion if the PSDU does not contain data intended for the receiving device or if the receiving device is unable to demodulate the at least one PSDU portion according to the corresponding PHY operation used to modulate the at least one PSDU portion; A circuit section configured as follows: Equipped with Receiving device.

15. 15. A receiving device according to claim 14, The circuit unit includes: deriving an Aggregated Media Access Control (MAC) Protocol Data Unit (A-MPDU) from the PSDU carried by the received PPDU, the A-MPDU including one or more first MAC Protocol Data Units (MPDUs) and one or more second MPDUs, the first PSDU portions of the received PSDU overlapping or corresponding to the one or more first MPDUs and the second PSDU portions overlapping or corresponding to the one or more second MPDUs; Demodulating the first PSDU portion if the first MPDU is destined for the receiving device, and / or demodulating the second PSDU portion if the second MPDU is destined for the receiving device. It is configured as follows: Receiving device.

16. 15. A receiving device according to claim 14, The circuitry is configured to demodulate second and / or further PSDU portions if they contain data intended for the receiving device, and / or to maintain OFDM symbol synchronization and / or codeword alignment if demodulation of the first PSDU portion is skipped. Receiving device.

17. 15. A receiving device according to claim 14, The circuit unit includes: a preamble of the PPDU; a signaling field present at the beginning of each PSDU part, and one or more additional training or signaling OFDM symbols included in the PPDU deriving PHY operation change signaling indicating modulation of the first PSDU portion and / or the second PSDU portion by a transmitting device from one of the It is configured as follows: Receiving device.

18. generating at least two physical layer (PHY) service data units (PSDUs); generating a PHY Protocol Data Unit (PPDU) from the PSDU, the PHY Protocol Data Unit including modulating the PSDU onto a plurality of OFDM symbols included in the PPDU, wherein a first PSDU portion of the PSDU corresponding to a first number of OFDM symbols undergoes a different PHY operation than a second PSDU portion of the PSDU corresponding to a second number of OFDM symbols; Transmitting the PPDU to at least two receiving devices. Sending method.

19. receiving a PHY Protocol Data Unit (PPDU) carrying a PSDU including at least a first PHY Service Data Unit (PSDU) portion and a second PSDU portion, the first PSDU portion being modulated by a PHY operation that is different from a PHY operation used to modulate the second PSDU portion; determining whether at least one PSDU portion contains data intended for a receiving device; demodulating the at least one PSDU portion or skipping demodulation of the at least one PSDU portion if the PSDU does not contain data intended for the receiving device or if the receiving device is unable to demodulate the at least one PSDU portion according to the corresponding PHY operation used to modulate the at least one PSDU portion; Receiving method.

20. A non-transitory computer-readable storage medium having stored thereon a computer program product which, when executed by a processor, causes the method of claim 18 or 19 to be performed.

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