Patent Description:
Although a frame transmission method as proposed below is applicable to various wireless communication systems, it will be described in the context of a WLAN system as an exemplary system to which the present disclosure is applicable.

Standards for WLAN technology have been developed as institute of electrical and electronics engineers (IEEE) <NUM> standards. IEEE <NUM>. 11a and b use an unlicensed band at <NUM> or <NUM>. IEEE <NUM>. 11b provides a transmission rate of <NUM> Mbps and IEEE <NUM>. 11a provides a transmission rate of <NUM> Mbps. IEEE <NUM> provides a transmission rate of <NUM> Mbps by applying orthogonal frequency division multiplexing (OFDM) at <NUM>. IEEE <NUM>. 11n provides a transmission rate of <NUM> Mbps for four spatial streams by applying multiple input multiple output (MIMO)-OFDM. IEEE <NUM>. 11n supports a channel bandwidth of up to <NUM> and, in this case, provides a transmission rate of <NUM> Mbps.

The above-described WLAN standards have evolved into IEEE <NUM>. 11ac that uses a bandwidth of up to <NUM> and supports a transmission rate of up to <NUM> Gbits/s for <NUM> spatial streams and IEEE <NUM>. 11ax standards are under discussion.

A station (STA) conforming to the IEEE <NUM>. 11ax standard may be referred to as a high efficiency (HE) STA, and a physical layer radio frame used in a HE system may be referred to as a HE physical protocol data unit (HE PPDU).

Each element of a PPDU available in the HE system will be described below.

<FIG> is a view referred to for describing initial discussion of each element of a HE PPDU.

In IEEE <NUM>. 11ax, a legacy 1x symbol structure (<NUM>) may be adopted for a part of a frame up to HE-SIGs (HE-SIG A and HE-SIG B), and a frame structure having a 4x symbol (<NUM>) structure may be used for HE-preamble and Data of the frame, as illustrated in <FIG>. Unless contradicting the following description, there is no problem with applying the present disclosure even though the above structure is changed.

An L-part may be configured as in a legacy wireless fidelity (Wi-Fi) system, and thus may include a legacy short training field (L-STF), a legacy long training field (L-LTF), and a legacy signal (L-SIG). Generally, the L-SIG preferably carries packet length information. A HE-part is a new part configured for the IEEE <NUM>. 11ax standard (High Efficiency). HE-SIGs (HE-SIG A and HE-SIG B) may be interposed between the L-part and a HE-STF, providing common control information and user-specific information. Specifically, the HE-SIGs may be configured separately as HE-SIG A for providing common control information and HE-SIG B for providing user-specific information.

Although the above HE PPDU format is applicable to all data transmissions of a STA, it is preferred to make a slight modification to the HE PPDU format according to a transmission state of the STA in order to increase system efficiency.

The proposed TGax draft specification IEEE <NUM>-16j0024r1 (Robert Stacey, Intel), <NUM> March <NUM>, XP068104773, discloses at section <NUM>. <NUM> HE modulation and coding schemes. In particular, an HE ER SU PPDU is transmitted in a resource unit with options of <NUM>-tone, <NUM>-tone, <NUM>-tone, <NUM>-tone, <NUM>-tone and <NUM>-tone.

Particular embodiments are set out in the respective dependent claims.

Accordingly, an aspect of the present disclosure is to provide physical protocol data unit (PPDU) formats available in a high efficiency (HE) system, particularly a method for transmitting and receiving a high efficiency extended range single user physical protocol data unit (HE ER SU PPDU), when a robust transmission is needed.

Additional advantages, objects, and features of the present disclosure will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the present disclosure. The objectives and other advantages of the present. While the present disclosure may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the disclosure, as embodied and broadly described herein, a method for transmitting data by a first station (STA) in a wireless local area network (WLAN) system is disclosed includes configuring, as a radio frame for transmission of the data, a high efficiency extended range single user physical protocol data unit (HE ER SU PPDU) in which a high efficiency signal A (HE-SIG-A) field is repeated, and transmitting the configured HE ER SU PPDU to a second STA in a resource unit (RU) of one of a first type and a second type, the first type having a size of <NUM> tones and the second type having a size of <NUM> tones. If the HE ER SU PPDU is transmitted in an RU of the first type, the HE ER SU PPDU is transmitted in an RU of the first type at a fixed position in a primary <NUM>-MHz channel.

It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the present disclosure as claimed.

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the present disclosure. In the drawings:.

Reference will now be made in detail to the preferred embodiments of the present disclosure with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure, rather than to show the only embodiments that can be implemented according to the present disclosure.

The following detailed description includes specific details in order to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be practiced without such specific details. In some instances, known structures and devices are omitted or are shown in block diagram form, focusing on important features of the structures and devices, so as not to obscure the concept of the present disclosure.

<FIG> are views illustrating a HE single user (SU) PPDU format and a HE multi-user (MU) PPDU format among HE PPDU formats which may be used in an embodiment of the present disclosure;.

A high efficiency (HE) system supports an SU transmission mode and an MU transmission mode. The HE SU PPDU illustrated in <FIG> may be used in the SU transmission mode, and the HE MU PPDU illustrated in <FIG> may be used in the MU transmission mode.

The HE SU PPDU does not need to include HE signal B (HE-SIG B) among the fields described with reference to <FIG> because HE-SIG B is used to transmit user-specific control information in the MU transmission mode, as described before. In the HE SU PPDU format, HE-SIG A is <NUM> long as illustrated in <FIG> and does not need to be repeated on a symbol basis, compared to a later-described HE ER SU PPDU.

Meanwhile, the HE MU PPDU illustrated in <FIG> is used in the MU transmission mode. The HE MU PPDU format may include HE-SIG B to transmit user-specific control information. The HE MU PPDU may also include an <NUM>-us HE-SIG-A field.

<FIG> is a view illustrating a HE trigger-based PPDU format among HE PPDU formats which may be used in an embodiment of the present disclosure.

Aside from a HE MU PPDU used in the MU transmission mode as illustrated in <FIG>, a HE trigger-based PPDU may be used as a PPDU transmitted in response to a trigger frame triggering uplink (UL) MU transmission, received from an access point (AP). Accordingly, a HE MU PPDU may be used mainly for downlink (DL) MU transmission as described later, whereas a HE trigger-based PPDU as illustrated in <FIG> may be used for UL MU transmission.

The HE trigger-based PPDU format illustrated in <FIG> is identical to the HE SU PPDU format illustrated in <FIG> in terms of the structures of legacy short training field (L-STF), legacy long training field (L-LTF), legacy signal (L-SIG), and HE-SIG-A fields, and different from the HE SU PPDU format in that the former may include a <NUM>-us HE-STF field as illustrated in <FIG>.

<FIG> are views illustrating a UL MU transmission scheme and a DL MU transmission scheme, respectively to describe an application example of each HE PPDU format.

Specifically, <FIG> illustrates a UL MU transmission situation. Referring to <FIG>, an AP may transmit a trigger frame on DL to schedule UL MU transmission of a plurality of STAs. The trigger frame may include scheduling information based on which the plurality of STAs transmit HE trigger-based PPDUs. Therefore, each STA may transmit a HE trigger-based PPDU as illustrated in <FIG>. The HE trigger-based PPDU is configured in the manner described with reference to <FIG>. The AP may transmit an acknowledge/negative acknowledgement (ACK/NACK) in response to a UL MU data transmission in the HE trigger-based PPDU. While the AP is shown as transmitting a block ACK (BA) in <FIG>, the AP may use a general ACK frame, a BA frame, or a multi-STA BA frame of a format common to the plurality of STAs in order to acknowledge or negative-acknowledge the UL MU data transmissions.

<FIG> illustrates a DL MU transmission situation. Referring to <FIG>, an AP may transmit DL data in a HE MU PPDU to a plurality of STAs during an acquired transmission opportunity (TXOP). The HE MU PPDU may include an aggregated MAC (medium access control) protocol data unit (A-MPDU) directed to each STA, as illustrated in <FIG>. The HE MU PPDU used for DL MU transmission may be configured in the format illustrated in <FIG>.

Each STA may transmit an ACK/NACK in the form of a BA in response to reception of the HE MU PPDU, as illustrated in <FIG>. Scheduling information is required to enable each STA to transmit an ACK/NACK in MU. While a trigger frame may be separately used for scheduling, the HE MU PPDU transmitted by the AP may include scheduling information for BA transmission, as illustrated in <FIG>, thereby increasing efficiency.

<FIG> is a view illustrating a HE ER SU PPDU format according to an embodiment of the present disclosure.

For SU transmission, a HE SU PPDU may be used, as illustrated in <FIG>. However, a STA needs a more robust type of transmission to extend coverage in a specific case in the HE system. A HE ER SU PPDU has been proposed to cover such an extended range, as illustrated in <FIG>.

The HE ER SU PPDU may have the following features.

To ensure the reliability and robust transmission of HE-SIG A, the symbols of HE-SIG A are repeated once and transmitted. In <FIG>, HE-SIG A is <NUM> long, which implies that each symbol of HE-SIG A in the HE SU PPDU of <FIG> is repeated once.

Further, it is preferred to boost the power of L-STF, L-LTF, HE-STF, and HE-LTF of the HE ER SU PPDU by 3dB relative to L-STF, L-LTF, HE-STF, and HE-LTF of the HE SU PPDU, for robust performance against a channel.

The HE ER SU PPDU is transmitted on a <NUM>-MHz primary channel, and preferably supports only one spatial stream (SS) and specific modulation and coding schemes (MCSs) (e.g., MCS0, MCS1, and MCS2). This simplifies the transmission structure of the HE ER SU PPDU used for robust transmission, and transmission of the HE ER SU PPDU with boosted power is favorable.

Based on the basic idea of a HE ER SU PPDU, a method for transmitting and receiving a HE ER SU PPDU will be described below in detail.

Considering that a HE ER SU PPDU is a special case of a HE SU PPDU, the following description will be given of the difference between a HE SU PPDU transmission scheme and a HE ER SU PPDU transmission scheme.

<FIG> is a view illustrating a structure of HE-SIG A in a HE SU PPDU used in an embodiment of the present disclosure.

In the HE SU PPDU, HE-SIG A includes <NUM>-bit information indicating whether the PPDU is for UL transmission or DL transmission. HE-SIG A further includes <NUM>-bit format information indicating whether the PPDU is a HE trigger-based PPDU or a HE SU PPDU.

A bandwidth (BW) field of HE-SIG A may be <NUM> bits long to indicate the transmission BW of the HE SU PPDU among <NUM>, <NUM>, <NUM>, and <NUM>. An MCS field may indicate a used MCS level in <NUM> bits.

The information illustrated in <FIG> has been defined in <NUM> bits, with the usage of <NUM> bits not defined.

Now, a description will be given of a method for transmitting and receiving a HE ER SU PPDU based on the above-described information of a HE SU PPDU, and a configuration of HE-SIG A as signalling information for the method.

IEEE <NUM>. 11ax regulates data transmission in OFDMA as mandatory, and defines four types of resource units (RUs) as listed in [Table <NUM>] below, for DL/UL transmission in a <NUM>-MHz BW.

<FIG> is a view illustrating a tone allocation scheme used in a HE system.

[Table <NUM>] below lists RU sizes and the numbers of RUs in <NUM> by type, when tones are allocated in the manner illustrated in <FIG>.

For example, if data is transmitted in a HE MU PPDU and a HE trigger-based PPDU, the above four types of RUs may be available. Therefore, when a HE ER SU PPDU is transmitted in OFDMA according to an embodiment of the present disclosure, the four types of RUs may also be considered.

In this context, the following three approaches are considered.

All of the four types of RUs may be available in transmitting a HE ER SU PPDU. That is, one of the four RU sizes (types) is selected and data is transmitted in an RU of the selected size during ER PPDU transmission.

Only the <NUM>-tone, <NUM>-tone, and <NUM>-tone RU types are used, among the four types of RUs.

Only the <NUM>-tone or <NUM>-tone RU type is used, among the four types of RUs.

Only the <NUM>-tone RU type is used, among the four types of RUs.

In the present invention, a HE ER SU PPDU transmission scheme based on Method <NUM> among the four approaches is used. The reason for preferring an RU of a large size among the available four types of RUs is that the use of a large RU requires less signalling information than use of a small RU and thus transmission is simplified, which is suitable for a HE ER SU PPDU for robust transmission.

However, if only the <NUM>-tone RU type is used as in Method <NUM>, a function of transmitting a signal adaptively according to a channel state is not viable, which is inefficient for robust transmission of a HE ER SU PPDU.

Further, the present invention proposes a transmission scheme in which only <NUM>-tone and <NUM>-tone RUs are used as described before, and when <NUM> tones are used in <NUM>, a HE ER SU PPDU is transmitted at a fixed position, thus obviating the need for additional signalling of the resource position. Therefore, if <NUM> tones are used, a HE ER SU PPDU is transmitted in a fixed <NUM>-tone RU in primary <NUM>, without the need for additional signalling.

Specific configurations of HE-SIG A under the above assumption will be described below.

Another advantage of selectively using <NUM> tones or <NUM> tones for a HE ER SU PPDU is that the selection may be indicated simply by <NUM>-bit control information. As described before, since the HE ER SU PPDU is transmitted in an RU type selected between the <NUM>-tone RU type and the <NUM>-tone RU type in primary <NUM>, <NUM>-bit information of the BW field of the HE ER SU PPDU, described with reference to <FIG>, may not be needed.

Therefore, the unnecessary BW field may be reused to indicate whether the RU type is <NUM> tones or <NUM> tones in an embodiment of the present disclosure.

<FIG> is a view illustrating a BW field in HE-SIG A according to an embodiment of the present disclosure.

Referring to <FIG>, the BW field of a HE SU PPDU indicates one of <NUM>, <NUM>, <NUM>, and <NUM> in <NUM> bits. On the other hand, only two out of four cases represented by a <NUM>-bit BW field of a HE ER SU PPDU may indicate whether a used RU has <NUM> tones or <NUM> tones, as illustrated in <FIG>. Obviously, additional control information may be transmitted using the other two cases in the HE ER SU PPDU.

If a HE ER SU PPDU is used, it may be configured that data is repeatedly transmitted, for robust data transmission in an embodiment of the present disclosure. That is, available resources in the Data field of the HE ER SU PPDU may be divided into two parts and data may be transmitted by repeatedly transmitting the same information twice.

For example, if the HE ER SU PPDU is transmitted in a <NUM>-tone RU, the available <NUM> tones may be divided by <NUM> tones, data may be mapped to <NUM> tones, and the same data may be mapped to the remaining <NUM> tones, for repeated transmission.

For this purpose, HE-SIG A may include <NUM>-bit control information indicating whether the above-described repeated transmission scheme is applied.

Dual carrier modulation (DCM) may be used as an example of the repeated transmission scheme. DCM may be regarded as repeated modulation of the same data to a pair of tones. However, when the same data is repeated, the second transmission data may be transmitted by phase rotation at a predetermined angle or conjugation.

<FIG> is a view illustrating the concept of including, in HE-SIG A, a field indicating whether a repeated transmission scheme is applied to a Data field of a HE ER SU PPDU according to an embodiment of the present disclosure.

While <FIG> illustrates DCM as the repeated transmission scheme by way of example, the repeated transmission scheme is not limited to DCM.

Referring to <FIG>, a <NUM>-bit DCM field indicates whether DCM is applied to the Data field by values <NUM> and <NUM>. Since DCM is intended for robust transmission, DCM is preferably restricted to MCS levels equal to or lower than a predetermined level. In the example of <FIG>, DCM is applied restrictively to MCS0, MCS1, MCS3, and MCS4. Further, DCM is limited to one or two spatial streams (SSs), not applied to space and time block code (STBC) in <FIG>.

As described before, a HE SU PPDU indicates an MCS level using <NUM>-bit information of HE-SIG A. In general, the HE SU PPDU may represent MCE level <NUM> to MCS level <NUM> by the <NUM>-bit information. On the other hand, the HE ER SU PPDU according to the embodiment of the present disclosure may use only the three lowest MCS levels for robust transmission with minimal signaling. Thus, the MCS field of HE-SIG A may be simplified in the HE ER SU PPDU.

<FIG> is a view illustrating MCS information in HE-SIG A of a HE ER SU PPDU according to an embodiment of the present disclosure.

Referring to <FIG>, the HE SU PPDU may indicate MCS level <NUM> to MCS level <NUM> using all of <NUM>-bit information, whereas the HE ER SU PPDU may indicate only MCS0, MCS1, and MCS2.

More specifically, if <NUM> tones are used for transmission of the HE ER SU PPDU, one of MCS0, MCS1, and MCS2 is indicated, and if <NUM> tones are used for transmission of the HE ER SU PPDU, MCS0 is fixedly used.

<FIG>, <FIG> are purely exemplary, and specific formats may be different from those illustrated in <FIG>, <FIG>. Because the HE ER SU PPDU uses fewer bits than the HE SU PPDU, the HE ER SU PPDU may represent additional control information by means of the remaining extra bits.

The above method for using <NUM> tones/<NUM> tones at a fixed position is not the only embodiment of the present disclosure, and other alternative embodiments will be described below.

A HE ER SU PPDU may be transmitted in an RU at a changed position, compared to the foregoing embodiment. The following examples may be considered.

As illustrated in [Table <NUM>], when an RU size or type different from the <NUM>-tone RU type is used, there are a plurality of RUs of the same size in <NUM>. Therefore, a channel state and interference may vary according to the positions of RUs in a BW. Thus, once one RU size is selected from a given RU set, an RU location having a minimal channel influence and a minimal interference influence is selected for RU transmission and data is transmitted in an RU at the selected position. The signal transmitted in the RU is transmitted with power boosted as much as the number of RUs of the RU size.

For example, if the <NUM>-tone RU type is used, there are two <NUM>-tone RUs in <NUM>. If the upper <NUM>-tone RU is in a better channel state than the lower <NUM>-tone RU, a signal is transmitted in the upper <NUM>-tone RU. Since the signal is transmitted only one of the two RUs, the signal may be transmitted with power boosting. Accordingly, the power of the transmitted signal may be boosted by at least twice (3dB) up to 3dB + alpha in consideration of extra power available by not using central <NUM> tones.

Once an RU size or type is determined for signal transmission, data is transmitted using the RU size. Herein, the data is repeatedly transmitted in RUs of the determined RU size in <NUM>. For example, if the <NUM>-tone RU type is used, there are four <NUM>-tone RUs in <NUM>, and thus the same data is repeatedly transmitted in the four <NUM>-tone RUs.

Owing to repeated transmissions of the same data in RUs of the same size, diversity and repetition gains may be achieved.

Further, data may be repeated within a selected RU size. Data is repeated, each time in an RU size smaller than a given RU size for transmission. For example, if a signal is transmitted in a <NUM>-tone RU, data is repeatedly transmitted, each time in an RU size of <NUM> tones.

An RU size for ER transmission is preferably equal to or larger than <NUM> tones. A transmission RU configured by repeating data in a smaller RU size may be transmitted in <NUM> in Method <NUM>, Method <NUM>, or Method <NUM>.

Further, a method for selecting an optimum band and an optimum RU size at the same time may be applied.

That is, a band or RU size in a good channel state with less interference is selected. Data is transmitted using the selected RU size. Specifically, the data is repeatedly transmitted in an RU size smaller than the selected RU size. For example, if an RU size used for transmission is <NUM> tones, a better RU between two <NUM>-tone RUs is selected, and data is loaded in a <NUM>-tone RU smaller than the RU size. The data is repeated on an <NUM>-tone RU basis and thus transmitted in the <NUM>-tone RU. The signal in the <NUM>-tone RU is transmitted with power boosting as described in (<NUM>).

To transmit an ER PPDU using various RU sizes in the above manner, information about a transmission RU size or type or information about an RU size should be transmitted in HE-SIG A. Therefore, HE-SIG A included in the ER PPDU may be configured based on information of HE-SIG A included in an SU PPDU, as follows.

RU information for transmission of a HE SU ER PPDU may be indicated by modifying a part of the fields included in HE-SIG A of a legacy SU PPDU, in consideration of the afore-described remaining bits (e.g., <NUM> bits) of HE-SIG A in a HE SU PPDU, and the following ER transmission situations.

If a signal is transmitted based on best band selection with power boosting, an indication is made through HE-SIG A, as follows.

An RU size used for ER PPDU transmission may be indicated using reserved bits (i.e., <NUM> bits) of HE-SIG A in a HE SU PPDU. For example, if RU sizes available for transmission are <NUM>, <NUM>, <NUM>, and <NUM> tones, a used RU size may be indicated using <NUM>-bit information as follows.

The above table is exemplary. Since four RU sizes are available, <NUM> bits are used. According to an RU size configuration used for transmission, each index may indicate a different RU size.

Since an ER PPDU is always transmitted in one SS, Nsts information included in HE-SIG A of a HE SU PPDU is not needed. Therefore, since information about an RU size used for transmission is transmitted in a field defined in the above example, the position of an RU carrying data may be determined, considering that the Nsts field indicates an RU allocation in ER transmission.

For example, each RU forms <NUM> as illustrated in <FIG>. In an embodiment of the present disclosure, it is assumed that RU locations are indicated sequentially from the left of the drawing. That is, it may be assumed that RUs are indicated in an order of low to high frequency indexes. This is a mere example, and thus ordering of positions is not limited in the present disclosure.

Thus, <NUM>-bit allocation information may be configured as follows.

Therefore, once an RU size is determined, each RU location is indicated as illustrated in [Table <NUM>].

The number of bits used for the allocation information may be changed according to a minimum RU size used for transmission. For example, if all RU sizes are available, <NUM>-tone RUs are at most positions. Since the number of <NUM>-tone RUs except for central <NUM> tones is <NUM>, an RU location may be indicated in <NUM> bits. Regarding other RU sizes except the <NUM>-tone RU size, however, if the <NUM>-tone RU size is used, there are four <NUM>-tone RUs. Then, an RU location may be indicated only in <NUM> bits. If the minimum RU size is <NUM> tones, an RU location may be indicated in <NUM> bit.

[Table <NUM>] below illustrates a case with a minimum RU size of <NUM> tones, and [Table <NUM>] below illustrates a case with a minimum RU size of <NUM> tones.

<FIG> is a table illustrating a structure of HE-SIG A in a HE ER SU PPDU according to an embodiment of the present disclosure.

Specifically, <FIG> illustrates HE-SIG A configured based on the description given with reference to [Table <NUM>] to [Table <NUM>].

In <FIG>, reference numeral <NUM> denotes use of <NUM> reserved bits in a HE SU PPDU, and reference numeral <NUM> denotes reuse of an Nsts field in a HE SU PPDU.

As illustrated in <FIG>, information needed for transmission of a HE ER SU PPDU may be transmitted in a field unnecessary for the HE ER SU PPDU among the fields of HE-SIG A in a HE SU PPDU.

<FIG> is a block diagram of apparatuses for performing the above-described methods.

Referring to <FIG>, a wireless apparatus <NUM> may be the afore-described specific STA, and a wireless apparatus <NUM> may be the afore-described AP.

The STA <NUM> may include a processor <NUM>, a memory <NUM>, and a transceiver <NUM>. The AP <NUM> may include a processor <NUM>, a memory <NUM>, and a transceiver <NUM>. The transceivers <NUM> and <NUM> may transmit and receive wireless signals and may be implemented in an IEEE <NUM>/3GPP physical layer. The processors <NUM> and <NUM> may be implemented in the physical layer and/or the MAC layer and connected to the transceivers <NUM> and <NUM>. The processors <NUM> and <NUM> may perform the forgoing HE ER SU PPDU transmission/ reception.

The processors <NUM> and <NUM> and/or the transceivers <NUM> and <NUM> may include Application-Specific Integrated Circuit (ASICs), other chip sets, logic circuits, and/or data processors. The memories <NUM> and <NUM> may include read only memories (ROMs), random access memories (RAMs), flash memories, memory cards, storage media, and/or other storage units. If an embodiment is implemented in software, the above-described methods may be performed in a module (e.g., a process or a function) performing the afore-described functions. The module may be stored in the memories <NUM> and <NUM> and executed by the processors <NUM> and <NUM>. The memories <NUM> and <NUM> may reside inside or outside the processors <NUM> and <NUM> and may be connected to the processors <NUM> and <NUM> by well-known means.

Claim 1:
A method for transmitting data by a first station, STA, in a wireless local area network, WLAN, system, the method comprising:
configuring a high efficiency extended range single user physical protocol data unit, HE ER SU PPDU for transmission of the data, wherein a high efficiency signal A, HE-SIG A, field of the HE ER SU PPDU is repeated; and
transmitting the HE ER SU PPDU to a second STA in a resource unit, RU, of only one of a first type and a second type among the first type, the second type, a third type and a fourth type within a <NUM>-MHz bandwidth, the RU of the third type and the fourth type are not used, and a bandwidth, BW, field of the HE-SIG A field of the HE ER SU PPDU indicates whether the HE ER SU PPDU uses the RU of the first type or the second type, the first type having a size of <NUM> tones, the second type having a size of <NUM> tones, the third type having a size of <NUM> tones and the fourth type having a size of <NUM> tones, wherein the BW field of the HE-SIG A field is used to indicate a transmission bandwidth among bandwidths being multiples of <NUM> in case of transmission of a high efficiency single user physical protocol data unit, HE SU PPDU, and
wherein, based on the HE ER SU PPDU being transmitted in the RU of the first type, the HE ER SU PPDU is transmitted in an RU of the first type at a fixed position in a primary <NUM>-MHz channel.