Patent Description:
Under current regulations by the Federal Communications Commission (FCC) regarding wireless communications in the <NUM>-GHz and <NUM>-GHz bands, the equivalent isotropically radiated power (EIRP) of a power spectral density (PSD) limit is capped at <NUM> dBm for <NUM>-MHz transmission and the transmission (Tx) power limit is capped at <NUM> dBm. With a reasonable Tx power assumption, the FCC requirement would not limit Tx power for narrow-bandwidth transmissions. On the other hand, the FCC requirement regarding <NUM>-GHz LPI applications is far more stringent than PSD requirement for the <NUM>-GHz and <NUM>-GHz bands. For instance, the EIRP limit is at <NUM> dBm/MHz for an access point (AP) in <NUM>-GHz LPI versus an EIRP limit of <NUM> dBm/MHz for APs in the <NUM>-GHz band. Similarly, the EIRP limit is at -<NUM> dBm/MHz for an non-AP in <NUM>-GHz LPI versus an EIRP limit of <NUM> dBm/MHz for APs in the <NUM>-GHz band. As there can be different sizes of distributed-tone (or interleaved-tone) RUs in different bandwidths, how subcarrier indices are assigned or otherwise distributed remains to be defined. Therefore, there is a need for a solution for subcarrier indices for distributed-tone RUs in <NUM> LPI systems.

Document <NPL>, and document<NPL>, disclose using distributed-tone RUs of different sizes.

The following summary is illustrative only and is not intended to be limiting in any way. That is, the following summary is provided to introduce concepts, highlights, benefits and advantages of the novel and non-obvious techniques described herein. Select implementations are further described below in the detailed description. Thus, the following summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter. The subject matter for which protection is sought is defined only by the claims.

An objective of the present disclosure is to provide schemes, concepts, designs, techniques, methods and apparatuses pertaining to subcarrier indices for distributed-tone RUs in <NUM> LPI systems. It is believed that the distributed-tone (or interleaved-tone) RU with the subcarrier indices generated under one or more of the schemes proposed herein may achieve an optimal performance in terms of number of tones in <NUM>, allow flexible scheduling for allocation of distributed-tone RU of any size (with no constraints or limitation), and support distributed-tone multi-RUs (dMRUs) such as dMRU(<NUM>+<NUM>) and dMRU(<NUM>+<NUM>). Methods according to the invention are defined in the independent claims. The dependent claims define preferred embodiments thereof.

It is noteworthy that, although description provided herein may be in the context of certain radio access technologies, networks and network topologies such as, Wi-Fi, the proposed concepts, schemes and any variation(s)/derivative(s) thereof may be implemented in, for and by other types of radio access technologies, networks and network topologies such as, for example and without limitation, Bluetooth, ZigBee, <NUM>th Generation (<NUM>)/New Radio (NR), Long-Term Evolution (LTE), LTE-Advanced, LTE-Advanced Pro, Internet-of-Things (IoT), Industrial IoT (IIoT) and narrowband IoT (NB-IoT). Thus, the scope of the present disclosure is not limited to the examples described herein.

The subject matter for which protection is sought is defined only by the claims.

Implementations in accordance with the present disclosure relate to various techniques, methods, schemes and/or solutions pertaining to subcarrier indices for distributed-tone RUs in <NUM> LPI systems. According to the present disclosure, a number of possible solutions may be implemented separately or jointly. That is, although these possible solutions may be described below separately, two or more of these possible solutions may be implemented in one combination or another.

It is noteworthy that, in the present disclosure, a <NUM>-tone regular RU may be interchangeably denoted as RU26 (or rRU26), a <NUM>-tone regular RU may be interchangeably denoted as RU52 (or rRU52), a <NUM>-tone regular RU may be interchangeably denoted as RU106 (or rRU106), a <NUM>-tone regular RU may be interchangeably denoted as RU242 (or rRU242), and so on. Moreover, an aggregate (<NUM>+<NUM>)-tone regular MRU may be interchangeably denoted as MRU78 (or rMRU78), an aggregate (<NUM>+<NUM>)-tone regular MRU may be interchangeably denoted as MRU132 (or rMRU132), and so on. Furthermore, in the present disclosure, a <NUM>-tone distributed-tone RU may be interchangeably denoted as dRU26, a <NUM>-tone distributed-tone RU may be interchangeably denoted as dRU52, a <NUM>-tone distributed-tone RU may be interchangeably denoted as dRU106, a <NUM>-tone distributed-tone RU may be interchangeably denoted as dRU242, and so on. Additionally, an aggregate (<NUM>+<NUM>)-tone distributed-tone MRU may be interchangeably denoted as dMRU78, an aggregate (<NUM>+<NUM>)-tone distributed-tone MRU may be interchangeably denoted as dMRU132, and so on. Since the above examples are merely illustrative examples and not an exhaustive listing of all possibilities, the same applies to regular RUs, distributed-tone RUs, MRUs, and distributed-tone MRUs of different sizes (or different number of tones). It is also noteworthy that, in the present disclosure, a bandwidth of <NUM> may be interchangeably denoted as BW20, a bandwidth of <NUM> may be interchangeably denoted as BW40, a bandwidth of <NUM> may be interchangeably denoted as BW80, a bandwidth of <NUM> may be interchangeably denoted as BW160, a bandwidth of <NUM> may be interchangeably denoted as BW240, and a bandwidth of <NUM> may be interchangeably denoted as BW320. It is further noteworthy that, in the present disclosure, a <NUM>-tone interleaved-tone RU may be interchangeably denoted as iRU26, a <NUM>-tone interleaved-tone RU may be interchangeably denoted as iRU52, a <NUM>-tone interleaved-tone RU may be interchangeably denoted as iRU106, a <NUM>-tone interleaved-tone RU may be interchangeably denoted as iRU242, and a <NUM>-tone interleaved-tone RU may be interchangeably denoted as iRU484.

Referring to <FIG>, network environment <NUM> may involve a communication entity <NUM> and a communication entity <NUM> communicating wirelessly (e.g., in a WLAN in accordance with one or more IEEE <NUM> standards). For instance, communication entity <NUM> may be a first STA and communication entity <NUM> may be a second STA, with each of the first STA and second STA functioning an access point (AP) STA or a non-AP STA. Under various proposed schemes in accordance with the present disclosure, communication entity <NUM> and communication entity <NUM> may be configured to communicate wirelessly with subcarrier indices for distributed-tone RUs in <NUM> LPI systems, as described herein.

Under various proposed schemes in accordance with the present disclosure, subcarrier indices may be specified in tables (e.g., in a style similar to that for regular RUs in IEEE <NUM>. 11ax/be) for different distributed-tone RU (dRU) sizes in different bandwidths (BWs). Under the various proposed schemes, both guard tones and DC tones may be taken into account in table formulation for the subcarrier indices for distributed-tone (or interleaved-tone) RUs. It is believed that the distributed-tone RUs with the subcarrier indices proposed herein may result in a number of benefits, including, for example: achieving the optimal performance in terms of number of tones in <NUM>, allowing flexible scheduling for allocation of dRU (or iRU) of any size (e.g., no constraint or limitation), support of distributed tone aggregation of multiple RUs (MRU) such as MRU(<NUM>+<NUM>) and MRU(<NUM>+<NUM>) to achieve optimal performance.

Under one proposed scheme in accordance with the present disclosure, there may be two design options for the subcarrier indices. In a first option (Option <NUM>), dRU tone distributions may be symmetric to DC tone(s). In a second option (Option <NUM>), dRU tone distributions may be asymmetric to the DC tone(s). Under another proposed scheme in accordance with the present disclosure, there may be two options for pilot indices for distributed-tone RUs. In a first option (Option A), relative pilot positions, as with regular RUs with respect to a first left-hand tone, may be preserved. In a second option (Option B), pilot tones may be assigned with symmetry to the DC tone.

<FIG> illustrates an example design <NUM> in accordance with an implementation of Option <NUM> under the proposed scheme. Design <NUM> pertains to assignment or distribution of subcarrier indices for distributed-tone RUs with the distributed-tone RUs being distributed in a symmetric fashion relative to one or more DC tones. As shown in <FIG>, in Option <NUM>, dRU tone distributions may be symmetric to a number of DC tones, with a horizonal axis being subcarrier indices and a vertical axis being distributed-tone RU (dRU) index in a permutation order. In design <NUM>, each dRU may include a left-side portion (Lru) and a right-side portion (Rru) relative to a center DC tone among one or more DC tones. The distribution of Lru and Rru may be symmetric to the center DC tone in two ways. Firstly, the center DC tone is located symmetrically in the middle between Lru and Rru, with Lru being to the left of the center DC tone and Rru being to the right of the center DC tone along the axis of subcarrier indices and with an equal distance between the center DC tone and Lru as well as between the center DC tone and Rru. Secondly, a pattern of tone distribution in Lru and a pattern of tone distribution in Rru in design <NUM> may be symmetric with respect to the center DC tone, as can be seen in <FIG>. There may be one or more guard tones to the left of Lru. Similarly, there may be one or more guard tones to the right or Rru. Under the proposed scheme, Lru and Rru indices may be generated based on a general rule of dRU design.

<FIG> illustrates an example design <NUM> in accordance with an implementation of Option <NUM> under the proposed scheme. Design <NUM> pertains to assignment or distribution of subcarrier indices for distributed-tone RUs with the distributed-tone RUs being distributed in a non-symmetric or asymmetric fashion relative to one or more DC tones. As shown in <FIG>, in Option <NUM>, dRU tone distributions may be asymmetric to a number of DC tones, with a horizonal axis being subcarrier indices and a vertical axis being dRU index in a permutation order. In design <NUM>, each dRU may include a left-side portion (Lru) and a right-side portion (Rru) relative to a center DC tone among one or more DC tones. The distribution of Lru and Rru may be non-symmetric or asymmetric to the center DC tone in two ways. Firstly, the center DC tone is located asymmetrically in the middle between Lru and Rru, with Lru being to the left of the center DC tone and Rru being to the right of the center DC tone along the axis of subcarrier indices and with an first distance between the center DC tone and Lru and a second distance between the center DC tone and Rru different from the first distance. Put differently, design <NUM> may be seen as design <NUM> being shifted toward one side (either the left side or the right side) of the center DC tone. In the example shown in <FIG>, the first distance between the center DC tone and Lru is greater than the second distance between the center DC tone and Rru, although in actual implementations the situation may be the opposite. Accordingly, in the example shown in <FIG>, the distribution of left-side portion and right-side portion may be seen as being equivalent to shifting a symmetric distribution (e.g., that of design <NUM>) to one side (e.g., left side) of the center DC tone. Secondly, a pattern of tone distribution in Lru and a pattern of tone distribution in Rru in design <NUM> may be non-symmetric or asymmetric with respect to the center DC tone, as can be seen in <FIG>. There may be one or more guard tones to the left of Lru. Similarly, there may be one or more guard tones to the right or Rru. Under the proposed scheme, Lru and Rru indices may be generated based on a general rule of iRU design.

Each of <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG> shows a respective example design for cases in which assignment or distribution of subcarrier indices for distributed-tone RUs is symmetric to the center DC tone. Each of these figures is further described below.

<FIG> illustrates an example design <NUM> of assignment or distribution of subcarrier indices for dRUs over BW20. It is noteworthy that in the present disclosure, each entry may be generalized as [-a:Dtd:-b b:Dtd:a], with "-a" denoting a left-most tone of a given dRU in the lower portion, "-b" denoting a right-most tone of the dRU in the lower portion, and "Dtd" denoting a tone distance between two adjacent tones of the dRU. It is also noteworthy that, instead of -<NUM>, in design <NUM> the value of -<NUM> or -<NUM> may be used as the first left-side tone and, in such a case, other tone indices may need to be adjusted accordingly. Additionally, in the field of "dRU index and subcarrier range" for <NUM>-tone dRU and <NUM>-tone dRU, ". " denotes the "V+n*Np" progression corresponding to the incrementation of n = <NUM>,<NUM>,. Moreover, fliplr(Lru) = Lru(end:-<NUM>:<NUM>), and the terms Np, V, S may be specified with other numbers.

<FIG> and <FIG> each illustrates a respective portion of an example design <NUM> of assignment or distribution of subcarrier indices for a <NUM>-tone dRU. Specifically, <FIG> shows a left-side (or lower) portion (Lru) of the <NUM>-tone dRU, and <FIG> shows a right-side (or upper) portion (Rru) of the <NUM>-tone dRU. The Lru and Rru of the <NUM>-tone dRU may be symmetric to one or more DC tones including a center DC tone.

<FIG> illustrates an example design <NUM> of assignment or distribution of subcarrier indices for dRUs over BW40. It is noteworthy that, instead of -<NUM>, in design <NUM> the value of -<NUM> may be used as the first left-side tone and, in such a case, other tone indices may need to be adjusted accordingly.

<FIG> illustrates an example design <NUM> of assignment or distribution of subcarrier indices for dRUs over BW80. It is noteworthy that, instead of -<NUM>, in design <NUM> the value of -<NUM> may be used as the first left-side tone and, in such a case, other tone indices may need to be adjusted accordingly. It is also noteworthy that dRU subcarrier indices for BW160 and BW320 may be generated following the same methodology/procedure as for BW20, BW40 and BW80 described and shown herein.

<FIG> and <FIG> each illustrates a respective portion of an example design <NUM> of assignment or distribution of pilot indices for a <NUM>-tone dRU. Specifically, <FIG> shows assignment or distribution of pilot indices for a <NUM>-tone dRU under Option A, which preserves the relative pilot positions as regular RUs with respect to the first left-hand tone. It is noteworthy that dRU pilot indices for BW160 and BW320 under Option A may be generated following the same methodology/procedure as for BW20, BW40 and BW80 described and shown herein. <FIG> shows assignment or distribution of pilot indices for a <NUM>-tone dRU under Option B such that pilot tones are symmetric to one or more DC tones including a center DC tone. It is noteworthy that dRU pilot indices for BW160 and BW320 under Option B may be generated following the same methodology/procedure as for BW20, BW40 and BW80 described and shown herein.

<FIG> and <FIG> each illustrates a respective portion of an example design <NUM> of assignment or distribution of pilot indices for a <NUM>-tone dRU. Specifically, <FIG> shows assignment or distribution of pilot indices for a <NUM>-tone dRU under Option A, which preserves the relative pilot positions as regular RUs with respect to the first left-hand tone. It is noteworthy that dRU pilot indices for BW160 and BW320 under Option A may be generated following the same methodology/procedure as for BW20, BW40 and BW80 described and shown herein. <FIG> shows assignment or distribution of pilot indices for a <NUM>-tone dRU under Option B such that pilot tones are symmetric to one or more DC tones including a center DC tone. It is noteworthy that iRU pilot indices for BW160 and BW320 under Option B may be generated following the same methodology/procedure as for BW20, BW40 and BW80 described and shown herein.

<FIG> illustrates an example design <NUM> of assignment or distribution of pilot indices for a <NUM>-tone dRU. Specifically, part (A) of <FIG> shows assignment or distribution of pilot indices for a <NUM>-tone dRU under Option A, which preserves the relative pilot positions as regular RUs with respect to the first left-hand tone. It is noteworthy that iRU pilot indices for BW160 and BW320 under Option A may be generated following the same methodology/procedure as for BW20, BW40 and BW80 described and shown herein. Part (B) of <FIG> shows assignment or distribution of pilot indices for a <NUM>-tone iRU under Option B such that pilot tones are symmetric to one or more DC tones including a center DC tone. It is noteworthy that iRU pilot indices for BW160 and BW320 under Option B may be generated following the same methodology/procedure as for BW20, BW40 and BW80 described and shown herein.

<FIG> illustrates an example design <NUM> of assignment or distribution of pilot indices for a <NUM>-tone dRU. Specifically, part (A) of <FIG> shows assignment or distribution of pilot indices for a <NUM>-tone dRU under Option A, which preserves the relative pilot positions as regular RUs with respect to the first left-hand tone. It is noteworthy that dRU pilot indices for BW160 and BW320 under Option A may be generated following the same methodology/procedure as for BW20, BW40 and BW80 described and shown herein. Part (B) of <FIG> shows assignment or distribution of pilot indices for a <NUM>-tone dRU under Option B such that pilot tones are symmetric to one or more DC tones including a center DC tone. It is noteworthy that iRU pilot indices for BW160 and BW320 under Option B may be generated following the same methodology/procedure as for BW20, BW40 and BW80 described and shown herein.

Each of <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG> shows a respective example design for cases in which assignment or distribution of subcarrier indices for interleaved-tone RUs is not symmetric to the center DC tone (e.g., shifted to one side with respect to the center DC tone). Each of these figures is further described below.

<FIG> illustrates an example design <NUM> of assignment or distribution of subcarrier indices for iRUs over BW20. It is noteworthy that, instead of -<NUM>, in design <NUM> the value of -<NUM> or -<NUM> may be used as the first left-side tone and, in such a case, other tone indices may need to be adjusted accordingly.

<FIG> illustrates an example design <NUM> of assignment or distribution of pilot indices for a <NUM>-tone dRU. It is noteworthy that dRU pilot indices for BW160 and BW320 may be generated following the same methodology/procedure as for BW20, BW40 and BW80 described and shown herein.

Under a proposed scheme in accordance with the present disclosure, dRU subcarrier indices may be generated with one or more traits or characteristics. For instance, dRU subcarrier indices may be generated to be edge-tone aligned (e.g., being aligned with the first left-hand tone) and DC tone-symmetric (e.g., symmetric with respect to a center DC tone of one or more DC tones as shown in design <NUM>). Alternatively, dRU subcarrier indices may be generated to be center aligned and also DC tone-symmetric. Alternatively, dRU subcarrier indices may be generated to be edge-tone aligned but DC tone-asymmetric (e.g., asymmetric or not symmetric with respect to a center DC tone of one or more DC tones as shown in design <NUM>). Alternatively, dRU subcarrier indices may be generated to be center aligned but DC tone-asymmetric.

Under another proposed scheme in accordance with the present disclosure, dRU subcarrier indices may be defined in one of multiple approaches. In a first approach, dRU subcarrier indices may be defined in a pure formula based fashion. In a second approach, dRU subcarrier indices may be defined with all the indices listed in one or more tables. In a third approach, dRU subcarrier indices may be defined by listing only the indices for a <NUM>-tone dRU (or the indices for both the <NUM>-tone dRU and a <NUM>-tone dRU) in a table such that indices for larger-sized dRUs (e.g., <NUM>-tone dRU, <NUM>-tone dRU, <NUM>-tone dRU and <NUM>-tone dRU) may be represented or otherwise built from the <NUM>-tone dRU based on dRU hierarchical structure, plus any extra tones for padding if necessary. For instance, indices for the <NUM>-tone dRU may be generated or defined based on two <NUM>-tone dRUs. Similarly, indices for the <NUM>-tone dRU may be generated or defined based on four <NUM>-tone dRUs or two <NUM>-tone dRUs plus padding with two extra tones. Likewise, indices for the <NUM>-tone dRU may be generated or defined based on two <NUM>-tone dRUs and one <NUM>-tone dRU plus padding with four extra tones. Moreover, indices for the <NUM>-tone dRU may be generated or defined based on two <NUM>-tone dRUs, and so on.

Each of <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG> shows a respective example design under the proposed schemes. Each of these figures is further described below.

<FIG> illustrates an example design <NUM> of generation of subcarrier indices for dRUs over BW20. Specifically, design <NUM> shows an example of generating dRUs of <NUM> tones, <NUM> tones and <NUM> tones that are edge-tone aligned and DC tone-symmetric. It is noteworthy that, in design <NUM>, the dRU1 of the <NUM>-tone iRU may alternatively be defined with <NUM>-tone [dRU1, dRU2] plus two extra tones and that the dRU2 of the <NUM>-tone dRU may alternatively be defined with <NUM>-tone [dRU3, dRU4] plus two extra tones.

<FIG> illustrates an example design <NUM> of generation of subcarrier indices for dRUs over BW20. Specifically, design <NUM> shows an example of generating dRUs of <NUM> tones, <NUM> tones and <NUM> tones that are center aligned and DC tone-symmetric. It is noteworthy that, in design <NUM>, the dRU1 of the <NUM>-tone dRU may alternatively be defined with <NUM>-tone [dRU1, dRU2] plus padding with two extra tones and that the dRU2 of the <NUM>-tone dRU may alternatively be defined with <NUM>-tone [dRU3, dRU4] plus padding with two extra tones.

<FIG> illustrates an example design <NUM> of generation of subcarrier indices for dRUs over BW20. Specifically, design <NUM> shows an example of generating dRUs of <NUM> tones, <NUM> tones and <NUM> tones that are edge-tone aligned and DC tone-asymmetric. It is noteworthy that, in design <NUM>, the dRU1 of the <NUM>-tone dRU may alternatively be defined with <NUM>-tone [dRU1, dRU2] plus padding two extra tones and that the dRU2 of the <NUM>-tone dRU may alternatively be defined with <NUM>-tone [dRU3, dRU4] plus padding with two extra tones.

<FIG> illustrates an example design <NUM> of generation of subcarrier indices for dRUs over BW20. Specifically, design <NUM> shows an example of generating dRUs of <NUM> tones, <NUM> tones and <NUM> tones that are center aligned and DC tone-asymmetric. It is noteworthy that, in design <NUM>, the dRU1 of the <NUM>-tone dRU may alternatively be defined with <NUM>-tone [dRU1, dRU2] plus padding with two extra tones and that the dRU2 of the <NUM>-tone dRU may alternatively be defined with <NUM>-tone [dRU3, dRU4] plus padding with two extra tones.

<FIG> illustrates an example design <NUM> of generation of subcarrier indices for dRUs over BW40. Specifically, design <NUM> shows an example of generating dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are edge-tone aligned and DC tone-symmetric.

<FIG> illustrates an example design <NUM> of generation of subcarrier indices for dRUs over BW40. Specifically, design <NUM> shows an example of generating dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are center aligned and DC tone-symmetric.

<FIG> illustrates an example design <NUM> of generation of subcarrier indices for dRUs over BW40. Specifically, design <NUM> shows an example of generating dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are edge-tone aligned and DC tone-asymmetric.

<FIG> illustrates an example design <NUM> of generation of subcarrier indices for dRUs over BW40. Specifically, design <NUM> shows an example of generating dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are center aligned and DC tone-asymmetric.

<FIG>, <FIG>, <FIG> and <FIG> each illustrates a respective portion of an example design <NUM> of generation of subcarrier indices for dRUs over BW80. Specifically, <FIG> shows an example of generating some dRUs of <NUM> tones that are edge-tone aligned and DC tone-symmetric, <FIG> shows an example of generating some other dRUs of <NUM> tones that are edge-tone aligned and DC tone-symmetric, <FIG> shows an example of generating some dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are edge-tone aligned and DC tone-symmetric, and <FIG> shows an example of generating some other dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are edge-tone aligned and DC tone-symmetric.

<FIG>, <FIG>, <FIG> and <FIG> each illustrates a respective portion of an example design <NUM> of generation of subcarrier indices for dRUs over BW80. Specifically, <FIG> shows an example of generating some dRUs of <NUM> tones that are center aligned and DC tone-symmetric, <FIG> shows an example of generating some other iRUs of <NUM> tones that are center aligned and DC tone-symmetric, <FIG> shows an example of generating some dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are center aligned and DC tone-symmetric, and <FIG> shows an example of generating some other dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are center aligned and DC tone-symmetric.

<FIG>, <FIG>, <FIG> and <FIG> each illustrates a respective portion of an example design <NUM> of generation of subcarrier indices for dRUs over BW80. Specifically, <FIG> shows an example of generating some dRUs of <NUM> tones that are edge-tone aligned and DC tone-asymmetric, <FIG> shows an example of generating some other dRUs of <NUM> tones that are edge-tone aligned and DC tone-asymmetric, <FIG> shows an example of generating some dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are edge-tone aligned and DC tone-asymmetric, and <FIG> shows an example of generating some other dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are edge-tone aligned and DC tone-asymmetric.

<FIG>, <FIG>, <FIG> and <FIG> each illustrates a respective portion of an example design <NUM> of generation of subcarrier indices for dRUs over BW80. Specifically, <FIG> shows an example of generating some dRUs of <NUM> tones that are center aligned and DC tone-asymmetric, <FIG> shows an example of generating some other dRUs of <NUM> tones that are center aligned and DC tone-asymmetric, <FIG> shows an example of generating some dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are center aligned and DC tone-asymmetric, and <FIG> shows an example of generating some other dRUs of <NUM> tones, <NUM> tones, <NUM> tones and <NUM> tones that are center aligned and DC tone-asymmetric.

<FIG> illustrates an example system <NUM> having at least an example apparatus <NUM> and an example apparatus <NUM> in accordance with an implementation of the present disclosure. Each of apparatus <NUM> and apparatus <NUM> may perform various functions to implement schemes, techniques, processes and methods described herein pertaining to subcarrier indices for distributed-tone RUs (dRU) in <NUM> LPI systems, including the various schemes described above with respect to various proposed designs, concepts, schemes, systems and methods described above as well as processes described below. For instance, apparatus <NUM> may be an example implementation of communication entity <NUM>, and apparatus <NUM> may be an example implementation of communication entity <NUM>.

Each of apparatus <NUM> and apparatus <NUM> may be a part of an electronic apparatus, which may be a STA or an AP, such as a portable or mobile apparatus, a wearable apparatus, a wireless communication apparatus or a computing apparatus. For instance, each of apparatus <NUM> and apparatus <NUM> may be implemented in a smartphone, a smart watch, a personal digital assistant, a digital camera, or a computing equipment such as a tablet computer, a laptop computer or a notebook computer. Each of apparatus <NUM> and apparatus <NUM> may also be a part of a machine type apparatus, which may be an IoT apparatus such as an immobile or a stationary apparatus, a home apparatus, a wire communication apparatus or a computing apparatus. For instance, each of apparatus <NUM> and apparatus <NUM> may be implemented in a smart thermostat, a smart fridge, a smart door lock, a wireless speaker or a home control center. When implemented in or as a network apparatus, apparatus <NUM> and/or apparatus <NUM> may be implemented in a network node, such as an AP in a WLAN.

In some implementations, each of apparatus <NUM> and apparatus <NUM> may be implemented in the form of one or more integrated-circuit (IC) chips such as, for example and without limitation, one or more single-core processors, one or more multi-core processors, one or more reduced-instruction set computing (RISC) processors, or one or more complex-instruction-set-computing (CISC) processors. In the various schemes described above, each of apparatus <NUM> and apparatus <NUM> may be implemented in or as a STA or an AP. Each of apparatus <NUM> and apparatus <NUM> may include at least some of those components shown in <FIG> such as a processor <NUM> and a processor <NUM>, respectively, for example. Each of apparatus <NUM> and apparatus <NUM> may further include one or more other components not pertinent to the proposed scheme of the present disclosure (e.g., internal power supply, display device and/or user interface device), and, thus, such component(s) of apparatus <NUM> and apparatus <NUM> are neither shown in <FIG> nor described below in the interest of simplicity and brevity.

In one aspect, each of processor <NUM> and processor <NUM> may be implemented in the form of one or more single-core processors, one or more multi-core processors, one or more RISC processors or one or more CISC processors. That is, even though a singular term "a processor" is used herein to refer to processor <NUM> and processor <NUM>, each of processor <NUM> and processor <NUM> may include multiple processors in some implementations and a single processor in other implementations in accordance with the present disclosure. In another aspect, each of processor <NUM> and processor <NUM> may be implemented in the form of hardware (and, optionally, firmware) with electronic components including, for example and without limitation, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors and/or one or more varactors that are configured and arranged to achieve specific purposes in accordance with the present disclosure. In other words, in at least some implementations, each of processor <NUM> and processor <NUM> is a special-purpose machine specifically designed, arranged and configured to perform specific tasks including those pertaining to subcarrier indices for distributed-tone RUs in <NUM> LPI systems in accordance with various implementations of the present disclosure. For instance, each of processor <NUM> and processor <NUM> may be configured with hardware components, or circuitry, implementing one, some or all of the examples described and illustrated herein.

In some implementations, apparatus <NUM> may also include a transceiver <NUM> coupled to processor <NUM>. Transceiver <NUM> may be capable of wirelessly transmitting and receiving data. In some implementations, apparatus <NUM> may also include a transceiver <NUM> coupled to processor <NUM>. Transceiver <NUM> may include a transceiver capable of wirelessly transmitting and receiving data.

Each of apparatus <NUM> and apparatus <NUM> may be a communication entity capable of communicating with each other using various proposed schemes in accordance with the present disclosure. For illustrative purposes and without limitation, a description of capabilities of apparatus <NUM>, as communication entity <NUM>, and apparatus <NUM>, as communication entity <NUM>, is provided below. It is noteworthy that, although the example implementations described below are provided in the context of WLAN, the same may be implemented in other types of networks. Thus, although the following description of example implementations pertains to a scenario in which apparatus <NUM> functions as a transmitting device and apparatus <NUM> functions as a receiving device, the same is also applicable to another scenario in which apparatus <NUM> functions as a receiving device and apparatus <NUM> functions as a transmitting device.

Under a proposed scheme in accordance with the present disclosure with respect to subcarrier indices for distributed-tone RUs (dRU) in <NUM> LPI systems, processor <NUM> of apparatus <NUM> may distribute frequency tones of a RU over a distribution bandwidth as a distributed-tone RU. Additionally, processor <NUM> may generate a plurality of subcarrier indices for the distributed-tone RU such that a distribution of the distributed-tone RU is symmetric to a DC tone along an axis of subcarrier indices. Alternatively, processor <NUM> may generate the plurality of subcarrier indices for the distributed-tone RU such that a distribution of the distributed-tone RU is non-symmetric or asymmetric to the DC tone along an axis of subcarrier indices. Furthermore, processor <NUM> may communicate wirelessly, via transceiver <NUM>, with apparatus <NUM> using the distributed-tone RU in a <NUM> LPI system.

In some implementations, the distributed-tone RU may include a left-side (or lower) portion and a right-side (or upper) portion relative to the DC tone along the axis of subcarrier indices. In case of symmetric distribution with respect to the DC tone, the left-side (or lower) portion may be on a left side of the DC tone and the right-side (or upper) portion may be on a right side of the DC tone with an equal distance between the DC tone and the left-side portion as well as between the DC tone and the right-side portion. In case of asymmetric distribution with respect to the DC tone, the left-side portion may be on a left side of the DC tone and the right-side portion may be on a right side of the DC tone with a first distance between the DC tone and the left-side portion and a second distance between the DC tone and the right-side portion different from the first distance.

In some implementations, in generating the plurality of subcarrier indices, processor <NUM> may generate edge-tone aligned and DC-symmetric subcarrier indices.

In some implementations, in generating the plurality of subcarrier indices, processor <NUM> may generate center aligned and DC-symmetric subcarrier indices.

In some implementations, in generating the plurality of subcarrier indices, processor <NUM> may generate edge-tone aligned and DC-asymmetric subcarrier indices.

In some implementations, in generating the plurality of subcarrier indices, processor <NUM> may generate center aligned and DC-asymmetric subcarrier indices.

In some implementations, the distributed-tone RU (dRU) may be distributed over a <NUM> bandwidth, and wherein the distributed-tone RU (dRU) comprises a <NUM>-tone dRU, a <NUM>-tone dRU or a <NUM>-tone dRU.

In some implementations, the distributed-tone RU (dRU) may be distributed over a <NUM> bandwidth, and wherein the distributed-tone RU (dRU) comprises a <NUM>-tone dRU, a <NUM>-tone dRU, a <NUM>-tone dRU or a <NUM>-tone dRU.

In some implementations, the distributed-tone RU (dRU) may be distributed over a <NUM> bandwidth, and wherein the distributed-tone RU (dRU)comprises a <NUM>-tone dRU, a <NUM>-tone dRU, a <NUM>-tone dRU, a <NUM>-tone dRU or a <NUM>-tone dRU.

In some implementations, the distributed-tone RU may include an aggregate of multiple dRUs (dMRU). For instance, the dMRU may include an aggregate of a <NUM>-tone dRU and a <NUM>-tone dRU (or otherwise denoted as dMRU(<NUM>+<NUM>)) or an aggregate of the <NUM>-tone dRU and a <NUM>-tone dRU (or otherwise denoted as dMRU(<NUM>+<NUM>)).

In some implementations, in generating the plurality of subcarrier indices, processor <NUM> may list or otherwise provide a set of subcarrier indices for a <NUM>-tone dRU in a table such that, for a larger-sized dRU with more than <NUM> tones, in generating the plurality of subcarrier indices, processor <NUM> may generate another set of subcarrier indices for the larger-sized dRU from the table and using a dRU hierarchical structure with or without one or more extra tones as padding. In some implementations, subcarrier indices for a <NUM>-tone dRU may be generated from corresponding two <NUM>-tone dRUs, subcarrier indices for a <NUM>-tone dRU may be generated from either corresponding four <NUM>-tone dRUs or corresponding two <NUM>-tone dRUs with two extra tones as padding, subcarrier indices for a <NUM>-tone dRU may be generated from corresponding two <NUM>-tone dRUs and one <NUM>-tone dRU with four extra tones as padding, and subcarrier indices for a <NUM>-tone dRU may be generated from corresponding two <NUM>-tone dRUs.

<FIG> illustrates an example process <NUM> in accordance with an implementation of the present disclosure. Process <NUM> may represent an aspect of implementing various proposed designs, concepts, schemes, systems and methods described above. More specifically, process <NUM> may represent an aspect of the proposed concepts and schemes pertaining to subcarrier indices for distributed-tone RUs in <NUM> LPI systems in accordance with the present disclosure. Process <NUM> may include one or more operations, actions, or functions as illustrated by one or more of blocks <NUM>, <NUM> and <NUM>. Although illustrated as discrete blocks, various blocks of process <NUM> may be divided into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Moreover, the blocks/sub-blocks of process <NUM> may be executed in the order shown in <FIG> or, alternatively in a different order. Furthermore, one or more of the blocks/sub-blocks of process <NUM> may be executed repeatedly or iteratively. Process <NUM> may be implemented by or in apparatus <NUM> and apparatus <NUM> as well as any variations thereof. Solely for illustrative purposes and without limiting the scope, process <NUM> is described below in the context of apparatus <NUM> as communication entity <NUM> (e.g., a transmitting device whether a STA or an AP) and apparatus <NUM> as communication entity <NUM> (e.g., a receiving device whether a STA or an AP) of a wireless network such as a WLAN in accordance with one or more of IEEE <NUM> standards. Process <NUM> may begin at block <NUM>.

At <NUM>, process <NUM> may involve processor <NUM> of apparatus <NUM> distributing frequency tones of a RU over a distribution bandwidth as a distributed-tone RU. Process <NUM> may proceed from <NUM> to <NUM>.

At <NUM>, process <NUM> may involve processor <NUM> generating a plurality of subcarrier indices for the distributed-tone RU such that a distribution of the distributed-tone RU is symmetric to a DC tone along an axis of subcarrier indices. Process <NUM> may proceed from <NUM> to <NUM>.

At <NUM>, process <NUM> may involve processor <NUM> communicating wirelessly, via transceiver <NUM>, with apparatus <NUM> using the distributed-tone RU in a <NUM> LPI system.

In some implementations, the distributed-tone RU may include a left-side (or lower) portion and a right-side (or upper) portion relative to the DC tone along the axis of subcarrier indices. Moreover, the left-side portion may be on a left side of the DC tone and the right-side portion may be on a right side of the DC tone with an equal distance between the DC tone and the left-side portion as well as between the DC tone and the right-side portion.

In some implementations, in generating the plurality of subcarrier indices, process <NUM> may involve processor <NUM> generating edge-tone aligned and DC-symmetric subcarrier indices.

In some implementations, in generating the plurality of subcarrier indices, process <NUM> may involve processor <NUM> generating center aligned and DC-symmetric subcarrier indices.

In some implementations, in generating the plurality of subcarrier indices, process <NUM> may involve processor <NUM> generating edge-tone aligned and DC-asymmetric subcarrier indices.

In some implementations, in generating the plurality of subcarrier indices, process <NUM> may involve processor <NUM> generating center aligned and DC-asymmetric subcarrier indices.

In some implementations, the distributed-tone (or interleaved-tone) RU may be distributed over a <NUM> bandwidth, and wherein the distributed-tone RU on BW20 comprises a <NUM>-tone dRU, a <NUM>-tone dRU or a <NUM>-tone dRU.

In some implementations, the distributed-tone (or interleaved-tone) RU may be distributed over a <NUM> bandwidth, and wherein the distributed-tone RU on BW40 comprises a <NUM>-tone dRU, a <NUM>-tone dRU, a <NUM>-tone dRU or a <NUM>-tone dRU.

In some implementations, the distributed-tone (or interleaved-tone) RU may be distributed over a <NUM> bandwidth, and wherein the distributed-tone RU on BW80 comprises a <NUM>-tone dRU, a <NUM>-tone dRU, a <NUM>-tone dRU, a <NUM>-tone dRU or a <NUM>-tone dRU.

In some implementations, in generating the plurality of subcarrier indices, process <NUM> may involve processor <NUM> listing or otherwise providing a set of subcarrier indices for a <NUM>-tone dRU in a table such that, for a larger-sized dRU with more than <NUM> tones, in generating the plurality of subcarrier indices, process <NUM> may further involve processor <NUM> generating another set of subcarrier indices for the larger-sized dRU from the table and using a dRU hierarchical structure with or without one or more extra tones as padding. In some implementations, subcarrier indices for a <NUM>-tone dRU may be generated from corresponding two <NUM>-tone dRUs, subcarrier indices for a <NUM>-tone dRU may be generated from either corresponding four <NUM>-tone dRUs or corresponding two <NUM>-tone dRUs with two extra tones as padding, subcarrier indices for a <NUM>-tone dRU may be generated from corresponding two <NUM>-tone dRUs and one <NUM>-tone dRU with four extra tones as padding, and subcarrier indices for a <NUM>-tone dRU may be generated from corresponding two <NUM>-tone dRUs.

<FIG> illustrates an example process <NUM> in accordance with an implementation of the present disclosure. Process <NUM> may represent an aspect of implementing various proposed designs, concepts, schemes, systems and methods described above. More specifically, process <NUM> may represent an aspect of the proposed concepts and schemes pertaining to subcarrier indices for distributed-tone RUs (dRU) in <NUM> LPI systems in accordance with the present disclosure. Process <NUM> may include one or more operations, actions, or functions as illustrated by one or more of blocks <NUM>, <NUM> and <NUM>. Although illustrated as discrete blocks, various blocks of process <NUM> may be divided into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Moreover, the blocks/sub-blocks of process <NUM> may be executed in the order shown in <FIG> or, alternatively in a different order. Furthermore, one or more of the blocks/sub-blocks of process <NUM> may be executed repeatedly or iteratively. Process <NUM> may be implemented by or in apparatus <NUM> and apparatus <NUM> as well as any variations thereof. Solely for illustrative purposes and without limiting the scope, process <NUM> is described below in the context of apparatus <NUM> as communication entity <NUM> (e.g., a transmitting device whether a STA or an AP) and apparatus <NUM> as communication entity <NUM> (e.g., a receiving device whether a STA or an AP) of a wireless network such as a WLAN in accordance with one or more of IEEE <NUM> standards. Process <NUM> may begin at block <NUM>.

At <NUM>, process <NUM> may involve processor <NUM> generating a plurality of subcarrier indices for the distributed-tone (or interleaved-tone) RU such that a distribution of the distributed-tone RU is non-symmetric or asymmetric to a DC tone along an axis of subcarrier indices. Process <NUM> may proceed from <NUM> to <NUM>.

In some implementations, the distributed-tone (or interleaved-tone) RU may include a left-side (or lower) portion and a right-side (or upper) portion relative to the DC tone along the axis of subcarrier indices. Moreover, the left-side portion may be on a left side of the DC tone and the right-side portion may be on a right side of the DC tone with a first distance between the DC tone and the left-side portion and a second distance between the DC tone and the right-side portion different from the first distance.

In some implementations, the distributed-tone (or interleaved-tone) RU may be distributed over a <NUM> bandwidth, and wherein the distributed-tone RU comprises a <NUM>-tone dRU, a <NUM>-tone dRU or a <NUM>-tone dRU.

In some implementations, the distributed-tone (or interleaved-tone) RU may be distributed over a <NUM> bandwidth, and wherein the distributed-tone RU comprises a <NUM>-tone dRU, a <NUM>-tone dRU, a <NUM>-tone dRU or a <NUM>-tone dRU.

In some implementations, the distributed-tone (or interleaved-tone) RU may be distributed over a <NUM> bandwidth, and wherein the distributed-tone RU comprises a <NUM>-tone dRU, a <NUM>-tone dRU, a <NUM>-tone dRU, a <NUM>-tone dRU or a <NUM>-tone dRU.

In some implementations, the distributed-tone (or interleaved-tone) RU may include an aggregate of multiple dRUs (dMRU). For instance, the dMRU may include an aggregate of a <NUM>-tone dRU and a <NUM>-tone dRU (or otherwise denoted as dMRU(<NUM>+<NUM>)) or an aggregate of the <NUM>-tone dRU and a <NUM>-tone dRU (or otherwise denoted as dMRU(<NUM>+<NUM>)).

Claim 1:
A method performed by a first wireless communication apparatus, the method comprising:
distributing frequency tones of a resource unit, in the following also referred to as RU, over a distribution bandwidth as a distributed-tone RU, in the following also referred to as dRU, (<NUM>);
generating a plurality of subcarrier indices for the distributed-tone RU such that a distribution of the distributed-tone RU is symmetric to a direct-current, in the following also referred to as DC, tone along an axis of subcarrier indices (<NUM>); and
communicating wirelessly with a second wireless communication apparatus using the distributed-tone RU in a <NUM> low-power indoor in the following also referred to as LPI, system (<NUM>);
characterized in that
the generating of the plurality of subcarrier indices comprises providing a set of subcarrier indices for a <NUM>-tone dRU in a table such that, for a larger-sized dRU with more than <NUM> tones, the generating of the plurality of subcarrier indices further comprises generating another set of subcarrier indices for the larger-sized dRU from the table and using a dRU hierarchical structure with or without one or more extra tones as padding, wherein:
subcarrier indices for a <NUM>-tone dRU are generated from corresponding two <NUM>-tone dRUs,
subcarrier indices for a <NUM>-tone dRU are generated from either corresponding four <NUM>-tone dRUs or corresponding two <NUM>-tone dRUs with two extra tones as padding,
subcarrier indices for a <NUM>-tone dRU are generated from corresponding two <NUM>-tone dRUs and one <NUM>-tone dRU with four extra tones as padding, and
subcarrier indices for a <NUM>-tone dRU are generated from corresponding two <NUM>-tone dRUs.