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. However, the FCC requirement regarding <NUM>-GHz low-power indoor (LPI) applications is far more stringent than PSD requirement regarding 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 the EIRP limit of <NUM> dBm/MHz for APs in the <NUM>-GHz band. Similarly, the EIRP limit is at -<NUM> dBm/MHz for an AP in <NUM>-GHz LPI versus the EIRP limit of <NUM> dBm/MHz for APs in the <NUM>-GHz band. Moreover, the European Telecommunications Standards Institute (ETSI) limit on PSD is even more stringent than that of the FCC. The challenge for <NUM>-GHz LPI is thus to achieve long-range transmission and reception while meeting the low-power requirements. Therefore, there is a need for a solution for long-range transmission and reception for low-power indoor applications in <NUM>-GHz band in WLANs. <CIT> discloses a method to decode a legacy preamble of a physical layer (PHY) protocol data unit (PPDU) to determine whether the legacy preamble comprises an indication that the PPDU is an extremely-high throughput (EHT) PPDU. <CIT> discloses a method for transmitting data over a non-contiguous set of tones. <CIT> discloses a wireless communication device of a first Extremely High Throughput (EHT) wireless station (STA).

The invention is defined by a method and an apparatus according to 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 loT (IIoT) and narrowband loT (NB-loT). Thus, the scope of the present disclosure is not limited to the examples described herein.

Implementations in accordance with the present disclosure relate to various techniques, methods, schemes and/or solutions pertaining to long-range transmission and reception for low-power indoor applications in <NUM>-GHz band in WLANs. 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.

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 being an access point (AP) 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 perform long-range transmission and reception for low-power indoor applications in <NUM>-GHz band, as described herein.

In general, at current time LPI tends to be more attractive than automated frequency coordination (AFC) even though LPI has more stringent regulations on PSD. This is because implementations of AFC would need a third-party to provide database, which is out of control of system and chip vendors. Television whitespace is an example. Also, although AFC may be useful in the future, LPI is currently available. Besides, even when AFC is ready, Unlicensed National Information Infrastructure (U-NII) <NUM> and <NUM> are only for LPI with a total of <NUM>-MHz band. On the other hand, the PSD constraints on LPI can be overcome with design changes.

With respect to a comparison between <NUM>-GHz LPI and <NUM>-GHz LPI, there are some differences especially differences in range. For instance, in <NUM>-GHz band, the range of uplink (UL) transmissions can be extended by using smaller-size resource units (RUs) for trigger-based physical-layer protocol data units (PPDUs). In <NUM>-GHz band, however, the range of UL transmissions cannot be extended by using small RUs for trigger-based PPDUs. For example, the range of a beacon transmitted in the <NUM>-GHz band using <NUM>-MHz PPDUs is half of that of a <NUM>-GHz beacon. In case a downlink (DL) trigger frame is transmitted using <NUM>-MHz PPDUs, and in case it is desirable for a STA to achieve a similar range by using small-size RUs, the issue of PSD limit would need to be resolved.

In short, there are two range-related issues in <NUM>-GHz LPI. A first issue is a general range issue of <NUM>-GHz LPI. That is, <NUM>-GHz LPI has a much shorter range compared to the <NUM>-GHz band. For a <NUM>-MHz beacon, <NUM> + <NUM> = <NUM> dBm in <NUM>-GHz band compared to <NUM> + <NUM> = <NUM> dBm in <NUM>-GHz band with a <NUM> dB difference. The range in <NUM>-GHz band is a fourth of that in <NUM>-GHz band and the coverage area of <NUM>-GHz LPI is merely one sixteenth of that of <NUM>-GHz band. Thus, a design of a new wide bandwidth (BW) LPI long-range (LR) PPDU is needed to address this issue. A second issue relates to the difference between UL transmission and DL transmission. That is, the difference is <NUM> dBm/MHz for DL versus -<NUM> dBm/MHz for UL. Distributed-tone RU is introduced to address the issue of UL-DL range difference by using a wider BW (e.g., <NUM>) for DL transmissions and a narrow BW (e.g., <NUM>) for UL transmissions. That is, wide BW LPI LR PPDU may be used to transmit beacons and single-user (SU) PPDUs to extend the range, thereby enlarging the size of the respective basic service set (BSS).

<FIG> illustrates an example design <NUM> of a format of a LPI LR PPDU under a proposed scheme in accordance with the present disclosure. Under the proposed scheme, a LPI LR PPDU in <NUM>-GHz LPI may be a <NUM>-MHz, <NUM>-MHz or <NUM>-MHz PPDU. The proposed scheme also provides a new LPI LR preamble and long-range transmission scheme for payload. Referring to part (A) of <FIG>, a LPI LR PPDU may include a number (e.g., <NUM>, <NUM> or <NUM>) of <NUM>-MHz legacy preambles, at least one LPI long range signal field (LR-SIG), at least one LPI LR short training field (LPI LR-STF), at least one LPI LR long training field (LPI LR-LTF), and at least one LPI LR payload. Under the proposed scheme, for the new LPI LR preamble, a <NUM>-MHz legacy preamble used in IEEE <NUM> a/g/n/ac or IEEE <NUM>. 11ax may be duplicated in frequency domain. Referring to part (B) of <FIG>, the <NUM>-MHz legacy preamble tin the LPI LR PPDU may be the <NUM>-MHz legacy preamble used in IEEE <NUM> a/g/n/ac or IEEE <NUM>. 11ax which may be duplicated or otherwise repeated in the frequency domain. For instance, for a <NUM>-MHz LPI LR preamble, the <NUM>-MHz legacy preamble may be duplicated/repeated four times. Similarly, for a <NUM>-MHz LPI LR preamble, the <NUM>-MHz legacy preamble may be duplicated/repeated eight times. Likewise, for a <NUM>-MHz LPI LR preamble, the <NUM>-MHz legacy preamble may be duplicated/repeated sixteen times. As shown in part (B) of <FIG>, the <NUM>-MHz legacy preamble used in IEEE <NUM>. 11a/g/n/ac may include a legacy short training field (L-STF), legacy long training field (L-LTF) and a legacy signal field (L-SIG). Similarly, the <NUM>-MHz legacy preamble used in IEEE <NUM>1ax may include a L-STF, L-LTF, a L-SIG and a repeated legacy signal field (RL-SIG). It is noteworthy that, although design <NUM> shows a <NUM>-MHz LPI LR PPDU under the proposed scheme, the concept presented herein may be applicable to a <NUM>-MHz or <NUM>-MHz LPI LR PPDU.

<FIG> illustrates an example design <NUM> of a LPI LR-SIG of a LPI LR PPDU under a proposed scheme in accordance with the present disclosure. Under the proposed scheme, the LR-SIG field may contain indications on modulation coding scheme (MCS), coding, LR PPDU format, and/or repetition factor to enable demodulation and decoding of the LPI LR payload. A length of the LPI LR-SIG field may be one orthogonal frequency-division multiplexing (OFDM) symbol or two OFDM symbols. Under the proposed scheme, the LPI LR-SIG field may be binary phase shift keying (BPSK) modulated and encoded over a <NUM>-MHz subchannel and then duplicated or otherwise repeated in each <NUM>-MHz subchannel in the frequency domain. Alternatively, or additionally, the LPI LR-SIG field may be BPSK modulated and encoded over a <NUM>-MHz, <NUM>-MHz, <NUM>-MHz or <NUM>-MHz band with information bits spread by a factor of <NUM>, <NUM>, <NUM> or <NUM>. Alternatively, a subchannel containing the LPI LR-SIG may be repeated by <NUM>, <NUM>, <NUM> or <NUM> times. For illustrative purposes and without limitation the scope of the present disclosure, part (A) of <FIG> shows a <NUM>-MHz LPI LR-SIG encoded, modulated over a <NUM>-MHz subchannel and duplicated/repeated four times for transmission over a <NUM>-MHz bandwidth. Part (B) of <FIG> shows a <NUM>-MHz MHz LPI LR-SIG encoded, modulated and transmitted over a <NUM>-MHz bandwidth. It is noteworthy that, although design <NUM> shows a <NUM>-MHz LPI LR-SIG under the proposed scheme, the concept presented herein may be applicable to a <NUM>-MHz or <NUM>-MHz LPI LR-SIG.

Under a proposed scheme in accordance with the present disclosure with respect to LR payload, there may be two approaches to enabling LR payload transmission and reception. A first approach under the proposed scheme may involve two low-rate full-BW transmission schemes, namely a repetition scheme and a low-rate coding scheme. Under the repetition scheme, a modulated signal may be duplicated on several tones that are separated from each other. For instance, the signal may be encoded on <NUM> and duplicated on <NUM> in the frequency domain. Alternatively, the encoding may be done on a large BW and then the signal may be duplicated on different tones such as, for example, by dual carrier modulation (DCM) or duplicate DCM. Under the low-rate coding scheme, low-rate codes may be utilized. A second approach under the proposed scheme may involve usage of distributed tone RU (DT-RU). For instance, the tones in small-size RUs (e.g., RUs of less than <NUM> tones) may be distributed on larger-size RUs (e.g., RUs of <NUM> or more tones).

<FIG> illustrates an example scenario <NUM> of DT-RU generation under a proposed scheme in accordance with the present disclosure. Under the proposed scheme, DT-RUs may be utilized for the payload of a LPI LR PPDU. The DT-RUs may be generated by applying a large-size tone distributor on the assigned RU(s). Referring to <FIG>, a <NUM>-tone RU (shown as "RU1" in <FIG>) and a <NUM>-tone RU (shown as "RU2" in <FIG>) may be distributed onto a <NUM>-tone RU. For instance, a local tone mapper (DTM) may be utilized to map tones onto small-size RU(s) and a tone distributor (DTD) may be utilized to distribute tones of the small-size RU(s) onto large-size RU(s) (e.g., a <NUM>-tone RU).

<FIG> illustrates an example scenario <NUM> of DT-RU generation under a proposed scheme in accordance with the present disclosure. Under the proposed scheme, a small-size RU may be mapped onto different large-size RUs using a large-size tone distributor DTD. For example, a <NUM>-tone RU may be mapped onto a <NUM>-tone RU using a tone distributor DTD = <NUM>. As another example, a <NUM>-tone RU may be mapped onto a <NUM>-tone RU using a tone distributor DTD = <NUM>. To optimize the distribution, tone spacing between every two adjacent tones in the large-size RUs may be larger than <NUM>. For illustrative purposes and without limiting the scope of the present disclosure, possible DTD parameters for large-size RUs are listed/shown in <FIG>. It is noteworthy that, in the table shown in <FIG>, DTD = <NUM> means no tone distribution. Moreover, option <NUM> indicated in the table refers to "per-<NUM> distribution" and option <NUM> indicated in the table refers to "global distribution over 2x996".

Under a proposed scheme in accordance with the present disclosure, LPI LR-STF and LPI LR-LTF may match the format for LR payload schemes. Under the proposed scheme, in case DT-RU is applied to the payload, then LPI LR-STF and LPI LR-LTF may contain the distributed tones corresponding to the DT-RU used in the payload. Moreover, in case low rate full-BW transmission scheme for payload is used, then LPI LR-STF and LPI LR-LTF may include either duplicated <NUM>-MHz STF and LFT or, alternatively, wide BW STF and LTF.

<FIG> illustrates an example design <NUM> of LPI LR PPDU under a proposed scheme in accordance with the present disclosure. Under the proposed scheme, a <NUM>-MHz PPDU may be duplicated over a wider BW. For instance, a <NUM>-MHz legacy preamble, a universal signal field (U-SIG), an extreme-high-throughput signal field (EHT-SIG), an EHT short training field (EHT-STF), an EHT long training field (EHT-LTF) and an EHT payload may be duplicated. It is noteworthy that the EHT-SIG for a LPI LR PPDU may have a <NUM> structure in each <NUM>-MHz band. Under the proposed scheme, one or more bits in the U-SIG or EHT-SIG may be utilized to indicate that this is a <NUM>-MHz-duplicate format LPI LR PPDU. Under the proposed scheme, for reception, <NUM>-MHz packet detection and maximum ratio combining (MRC) over four <NUM>-MHz subchannels may be performed on the U-SIG, EHT-SIG and EHT payload. For <NUM>-MHz band, <NUM> dB extra range may be obtained compared to a <NUM>-MHz PPDU.

<FIG> illustrates an example design <NUM> of LPI LR PPDU under a proposed scheme in accordance with the present disclosure. Under the proposed scheme, a <NUM>-MHz legacy preamble, U-SIG, EHT-SIG and EHT payload may be duplicated. It is noteworthy that the EHT-SIG for a LPI LR PPDU may have a <NUM> structure in each <NUM>-MHz band. Under the proposed scheme, for the EHT-STF and EHT-LTF, large BW EHT-STF and EHT-LTF may be utilized. For instance, a <NUM>-MHz LPI LR PPDU may utilize <NUM>-MHz EHT-STF and EHT-LTF. Under the proposed scheme, for reception, <NUM>-MHz packet detection and MRC over four <NUM>-MHz subchannels may be performed on the U-SIG, EHT-SIG and EHT payload. For <NUM>-MHz band, <NUM> dB extra range may be obtained compared to a <NUM>-MHz PPDU.

<FIG> illustrates an example design <NUM> of LPI LR PPDU under a proposed scheme in accordance with the present disclosure. Under the proposed scheme, a <NUM>-MHz legacy preamble, U-SIG and EHT-SIG may be duplicated. It is noteworthy that the EHT-SIG for a LPI LR PPDU may have a <NUM> structure in each <NUM>-MHz, <NUM>-MHz or <NUM>-MHz band. Under the proposed scheme, for the EHT-STF and EHT-LTF, large BW EHT-STF and EHT-LTF may be utilized. For instance, a <NUM>-MHz LPI LR PPDU may utilize <NUM>-MHz EHT-STF and EHT-LTF. Under the proposed scheme, an EHT payload may utilize large BW with low-rate full-BW transmission schemes described herein. Under the proposed scheme, for reception, <NUM>-MHz packet detection and MRC over four <NUM>-MHz subchannels may be performed on the U-SIG and EHT-SIG. For <NUM>-MHz band, <NUM> dB extra range may be obtained compared to a <NUM>-MHz PPDU.

<FIG> illustrates an example design <NUM> of LPI LR PPDU under a proposed scheme in accordance with the present disclosure. Under the proposed scheme, Under the proposed scheme, a <NUM>-MHz legacy preamble, U-SIG and EHT-SIG may be duplicated. It is noteworthy that the EHT-SIG for a LPI LR PPDU may have a <NUM> structure in each <NUM>-MHz band. Under the proposed scheme, an EHT-STF corresponding to DT-RU and an EHT-LTF corresponding to DT-RU may be selected from wide BW EHT-STF and EHT-LTF, respectively. DT-RU payload may be generated using DT-RU generation schemes described herein. Under the proposed scheme, for reception, <NUM>-MHz packet detection and MRC over four <NUM>-MHz subchannels may be performed on the U-SIG and EHT-SIG.

<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 long-range transmission and reception for low-power indoor applications in <NUM>-GHz band in WLANs, 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 long-range transmission and reception for low-power indoor applications in <NUM>-GHz band in WLANs 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.

According to the invention with respect to long-range transmission and reception for low-power indoor applications in <NUM>-GHz band in WLANs, processor <NUM> of apparatus <NUM> may establish, via the transceiver, a wireless communication link between a first STA (e.g., apparatus <NUM>) and a second STA (e.g., apparatus <NUM>) in a <NUM>-GHz band. Additionally, processor <NUM> may communicate, via transceiver <NUM>, between the first STA and the second STA (e.g., transmit or receive) in the <NUM>-GHz band using a LPI LR PPDU. For instance, processor <NUM> of apparatus <NUM> may generate the LPI LR PPDU and transmit the LPI LR PPDU, via transceiver <NUM>, to apparatus <NUM>. Correspondingly, processor <NUM> of apparatus <NUM> may receive the LPI LR PPDU, via transceiver <NUM>, and decode/process the LPI LR PPDU.

According to the invention, the LPI LR PPDU may include a legacy preamble, a U-SIG, an EHT-SIG, an EHT-STF, an EHT-LTF, and a payload.

According to the invention, each of the legacy preamble, U-SIG and EHT-SIG may be modulated and duplicated over multiple <NUM>-MHz subchannels by DCM or dual DCM for a <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth over which the LPI LR PPDU is transmitted. Moreover, each of the EHT-STF, EHT-LTF and payload is modulated and transmitted on an entirety of the <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth. In some implementations, each of the EHT-STF, EHT-LTF and payload may be transmitted with DT-RUs by: (i) mapping each local tone of the payload onto small-size RUs of less than <NUM> tones; and (ii) distributing tones in the small-size RUs onto large-size RUs of <NUM> or more tones. In such cases, the LPI LR-STF and LPI LR-LTF may contain distributed tones corresponding to the DT-RUs used in the payload.

Alternatively, each of the legacy preamble, U-SIG, EHT-SIG, EHT-STF, EHT-LTF and payload may be modulated and duplicated over multiple <NUM>-MHz subchannels for a <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth over which the LPI LR PPDU is transmitted.

Still alternatively, each of the legacy preamble, U-SIG, EHT-SIG and payload may be modulated and duplicated over multiple <NUM>-MHz subchannels for a <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth over which the LPI LR PPDU is transmitted. Moreover, each of the EHT-STF and EHT-LTF may be modulated and transmitted on an entirety of the <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth.

In some implementations, a preamble of the LPI LR PPDU may include a legacy preamble, one or more LPI LR-specific fields, and a payload.

In some implementations, the one or more LPI LR-specific fields may include a LPI LR-SIG containing indications on one or more of an MCS, coding, a LR PPDU format, and a repetition factor. In some implementations, the LPI LR-SIG may be modulated and encoded over <NUM>, <NUM> or <NUM> either with information bits spread by a factor of <NUM>, <NUM>, <NUM> or <NUM> or with a subchannel containing the LPI LR-SIG repeated <NUM>, <NUM>, <NUM> or <NUM> times.

In some implementations, the one or more LPI LR-specific fields may include a LPI LR-STF and a LPI LR-LTF. In some implementations, in communicating in the <NUM>-GHz band using the LPI LR PPDU, processor <NUM> may communicate with DT-RUs by: (i) mapping each local tone of the payload onto small-size RUs of less than <NUM> tones; and (ii) distributing tones in the small-size RUs onto large-size RUs of <NUM> or more tones. In such cases, the LPI LR-STF and LPI LR-LTF contain distributed tones corresponding to the DT-RUs used in the payload.

In some implementations, the one or more LPI LR-specific fields may include a LPI LR-STF and a LPI LR-LTF. In some implementations, in communicating in the <NUM>-GHz band using the LPI LR PPDU, processor <NUM> may transmit or receive the LPI LR PPDU with low rate full-bandwidth for the payload. In such cases, transmission of each of the LPI LR-STF and LPI LR-LTF may involve either: (a) transmitting each of the LPI LR-STF and LPI LR-LTF over duplicated <NUM>-MHz subchannels; or (b) transmitting each of the LPI LR-STF and LPI LR-LTF as a wide-bandwidth LPI LR-STF and LPI LR-LTF, respectively, over a <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth.

In some implementations, in communicating in the <NUM>-GHz band using the LPI LR PPDU, processor <NUM> may transmit or receive the LPI LR PPDU with low rate full-bandwidth transmission such that a signal carrying the LPI LR PPDU is modulated and duplicated on multiple tones that are separated.

In some implementations, in transmitting or receiving the LPI LR PPDU with low rate full-bandwidth transmission, processor <NUM> may encode the signal carrying LPI LR PPDU on a <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth. Additionally, processor <NUM> may duplicate the encoded signal on different tones.

In some implementations, in duplicating the encoded signal on different tones, processor <NUM> may duplicate the encoded signal on different tones by DCM or duplicate DCM.

Alternatively, in transmitting or receiving the LPI LR PPDU with low rate full-bandwidth transmission, processor <NUM> may encode the LPI LR PPDU on a <NUM>-MHz subchannel. Moreover, processor <NUM> may duplicate the encoded <NUM>-MHz subchannel multiple times.

In some implementations, in communicating in the <NUM>-GHz band using the LPI LR PPDU, processor <NUM> may communicate with DT-RUs by: (i) mapping each local tone onto small-size RUs of less than <NUM> tones; and (ii) distributing tones in the small-size RUs onto large-size RUs of <NUM> or more tones. In some implementations, a tone spacing between every two adjacent tones in the large-size RUs may be greater than <NUM>.

In some implementation, in communicating in the <NUM>-GHz band using the LPI LR PPDU, on the receiving end processor <NUM> may perform <NUM>-MHz packet detection and MRC over four <NUM>-MHz subchannels on the U-SIG and EHT-SIG of the LPI LR PPDU.

<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 long-range transmission and reception for low-power indoor applications in <NUM>-GHz band in WLANs 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> 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> does involve processor <NUM> of apparatus <NUM> establishing, via transceiver <NUM>, a wireless communication link between a first STA (e.g., apparatus <NUM>) and a second STA (e.g., apparatus <NUM>) in a <NUM>-GHz band. Process <NUM> may proceed from <NUM> to <NUM>.

At <NUM>, process <NUM> does involve processor <NUM> communicating, via transceiver <NUM>, between the first STA and the second STA in the <NUM>-GHz band using a LPI LR PPDU.

According to the invention, each of the legacy preamble, U-SIG and EHT-SIG is modulated and duplicated over multiple <NUM>-MHz subchannels by DCM or duplicate DCM for a <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth over which the LPI LR PPDU is transmitted. Moreover, each of the EHT-STF, EHT-LTF and payload is modulated and transmitted on an entirety of the <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth. In some implementations, each of the EHT-STF, EHT-LTF and payload is transmitted with DT-RUs by: (i) mapping each local tone of the payload onto small-size RUs of less than <NUM> tones; and (ii) distributing tones in the small-size RUs onto large-size RUs of <NUM> or more tones. In such cases, the LPI LR-STF and LPI LR-LTF may contain distributed tones corresponding to the DT-RUs used in the payload.

In some implementations, the one or more LPI LR-specific fields may include a LPI LR-STF and a LPI LR-LTF. In some implementations, in communicating in the <NUM>-GHz band using the LPI LR PPDU, process <NUM> may involve processor <NUM> communicating with DT-RUs by: (i) mapping each local tone of the payload onto small-size RUs of less than <NUM> tones; and (ii) distributing tones in the small-size RUs onto large-size RUs of <NUM> or more tones. In such cases, the LPI LR-STF and LPI LR-LTF contain distributed tones corresponding to the DT-RUs used in the payload.

In some implementations, the one or more LPI LR-specific fields may include a LPI LR-STF and a LPI LR-LTF. In some implementations, in communicating in the <NUM>-GHz band using the LPI LR PPDU, process <NUM> may involve processor <NUM> transmitting or receiving the LPI LR PPDU with low rate full-bandwidth for the payload. In such cases, transmission of each of the LPI LR-STF and LPI LR-LTF may involve either: (a) transmitting each of the LPI LR-STF and LPI LR-LTF over duplicated <NUM>-MHz subchannels; or (b) transmitting each of the LPI LR-STF and LPI LR-LTF as a wide-bandwidth LPI LR-STF and LPI LR-LTF, respectively, over a <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth.

In some implementations, in communicating in the <NUM>-GHz band using the LPI LR PPDU, process <NUM> may involve processor <NUM> transmitting or receiving the LPI LR PPDU with low rate full-bandwidth transmission such that a signal carrying the LPI LR PPDU is modulated and duplicated on multiple tones that are separated.

In some implementations, in transmitting or receiving the LPI LR PPDU with low rate full-bandwidth transmission, process <NUM> may involve processor <NUM> encoding the signal carrying LPI LR PPDU on a <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth. Additionally, process <NUM> may involve processor <NUM> duplicating the encoded signal on different tones.

In some implementations, in duplicating the encoded signal on different tones, process <NUM> may involve processor <NUM> duplicating the encoded signal on different tones by DCM or duplicate DCM.

Alternatively, in transmitting or receiving the LPI LR PPDU with low rate full-bandwidth transmission, process <NUM> may involve processor <NUM> encoding the LPI LR PPDU on a <NUM>-MHz subchannel. Moreover, process <NUM> may involve processor <NUM> duplicating the encoded <NUM>-MHz subchannel multiple times.

In some implementations, in communicating in the <NUM>-GHz band using the LPI LR PPDU, process <NUM> may involve processor <NUM> communicating with DT-RUs by: (i) mapping each local tone onto small-size RUs of less than <NUM> tones; and (ii) distributing tones in the small-size RUs onto large-size RUs of <NUM> or more tones. In some implementations, a tone spacing between every two adjacent tones in the large-size RUs may be greater than <NUM>.

In some implementation, in communicating in the <NUM>-GHz band using the LPI LR PPDU, on the receiving end process <NUM> may involve processor <NUM> performing <NUM>-MHz packet detection and MRC over four <NUM>-MHz subchannels on the U-SIG and EHT-SIG of the LPI LR PPDU.

Claim 1:
A method for an apparatus, wherein the apparatus is a first station, in the following also referred to as STA, comprising:
establishing a wireless communication link between a first station and a second STA in a <NUM>-GHz band (<NUM>); and
communicating between the first STA and the second STA in the <NUM>-GHz band using a low-power indoor, in the following also referred to as LPI, long range, in the following also referred to as LR, physical-layer protocol data unit, in the following also referred to as PPDU, (<NUM>),
wherein the LPI LR PPDU comprises a legacy preamble, a universal signal field, in the following also referred to as U-SIG, an extreme-high-throughput signal field, in the following also referred to as EHT-SIG, an extreme-high-throughput short training field, in the following also referred to as EHT-STF, an extreme-high-throughput long training field, in the following also referred to as EHT-LTF, and a payload,
wherein each of the legacy preamble, U-SIG and EHT-SIG is modulated and duplicated over multiple <NUM>-MHz subchannels for a <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth over which the LPI LR PPDU is transmitted, and wherein each of the EHT-STF, EHT-LTF and payload is modulated and transmitted on an entirety of the <NUM>-MHz, <NUM>-MHz or <NUM>-MHz bandwidth.