Patent Description:
The present disclosure provides communication techniques for use in OFDMA and MU-MIMO type multi-user simultaneous transmission technologies, and with applicability to other wired or wireless multi-user simultaneous transmission technologies.

Today, wireless local area networks (WLANs) are widely used for communications between various computer devices and for Internet access. A prominent WLAN technology is known as WiFi, which allows electronic devices to network, using the <NUM> and <NUM> gigahertz bands. The term WiFi refers to any WLAN product that is based on the Institute of Electrical and Electronics Engineers (IEEE) <NUM> standards.

In <NUM>, IEEE <NUM>. 11a and <NUM>. 11b standards were released for WiFi networks. 11a protocol can support data transmissions of up to <NUM> Mbps, whereas the <NUM>. 11b protocol has a longer range but maxing out at <NUM> Mbps data transmission speed.

In <NUM>, IEEE introduced <NUM> as a new WiFi standard. The <NUM> protocol was designed to operate at a maximum transfer rate of <NUM> Mbps while allowing for a longer range.

Subsequently, the adoption of <NUM>. 11n by IEEE, sometimes called Wireless-N, brought about the ability to transfer data up to <NUM> Mbps, and incorporated multiple wireless signals and antennas to support multiple-input and multiple-output (MIMO) technology. 11n protocol allows data to be transmitted on both <NUM> and <NUM> frequencies.

The latest WiFi technology from IEEE, i.e. the <NUM> ac standard, introduced advancements in dual-band technology, which allows data to be transmitted across multiple signals and bandwidths for maximum transmission rates of <NUM> Mbps with extended range and nearly uninterrupted transmission.

Document <CIT> (<NUM>-<NUM>-<NUM>) discloses a mixed mode preamble which includes a legacy portion (common portion) and a Very High Throughput (VHT) portion (multi-user (MU) portion). The preamble of the packet has the same structure whether the packet is a single-user (SU) <NUM>. llac packet or a multi-user (MU) <NUM>. llac packet. An SU/MU indication (i.e., whether a packet is a SU packet or a MU packet) is indicated in the VHTSIGA fields of the SU and MU preambles in various ways.

As WiFi technology continues to advance, multi-user simultaneous transmission techniques, such as Orthogonal Frequency Division Multiple Access (OFDMA) and Uplink (UL) Multi-User MIMO (MU-MIMO), are candidates for improving wireless network efficiency. Using these techniques, multiple stations (STA) can be allocated within a frame. These STA allocations require a communication of resource and packet information by an access point (AP) for use by each STA.

The present disclosure is directed to systems and methods for packet information indication in communication systems as shown and described herein. In particular, a wireless device may selectively include resource allocation/scheduling information in a frame to be transmitted to one or more other wireless devices. The resource allocation/scheduling may indicate channel/sub-channel assignment for each wireless device. The wireless devices may each utilize this received resource allocation/scheduling information to determine the appropriate segment/sub-band of the transmission that is intended for their receipt/consumption.

In one embodiment, a first signaling field (e.g., HE-SIG-A) may indicate whether the resource allocation/scheduling information is present in a second signaling field (e.g., HE-SIG-B) of the frame. For example, a single bit may be toggled to indicate the presence of the second signaling field and therefore the presence of the resource allocation/scheduling information in the frame. In one embodiment, multiple bits may be used to indicate the length of the second signaling field. In this embodiment, a length of zero indicates the absence of the second signaling field and accordingly the absence of the resource allocation/scheduling information.

In some instances the transmission of resource allocation/scheduling information may be avoided to reduce overhead and/or superfluous information. For example, in single user transmissions, resource allocation/scheduling information may be unnecessary as the channel will not be subdivided. In another example, resource allocation/scheduling information may not be needed for responses to a trigger frame (i.e., a frame that previously provided resource allocation/scheduling information) as the transmitter of the trigger frame is already aware of the resource allocation/scheduling information.

The following description contains specific information pertaining to implementations in the present disclosure. The drawings in the present application and their accompanying detailed description are directed to merely exemplary implementations. Unless noted otherwise, like or corresponding elements among the figures may be indicated by like or corresponding reference numerals. Moreover, the drawings and illustrations in the present application are generally not to scale, and are not intended to correspond to actual relative dimensions.

<FIG> illustrates network <NUM> including wireless area network (WLAN) <NUM> having a plurality of stations (STA) <NUM>/<NUM>/<NUM> in wireless communication with access point (AP) <NUM>. As shown in <FIG>, AP <NUM> is also in communication with computers <NUM>/<NUM> over wide area network or Internet <NUM>. WLAN <NUM> may be a WiFi network, which is established using any set of protocols, techniques, and standards, including protocols and techniques presented herein. In particular, each STA <NUM>/<NUM>/<NUM> is wirelessly connected to AP <NUM> and communicates with AP <NUM> using any set of protocols, techniques, and standards, including protocols and techniques presented herein. AP <NUM> is also connected to Internet <NUM> either through a wired connection, such as DSL or cable, or through a wireless connection, such as <NUM> or Long-Term Evolution (LTE). As such, each STA <NUM>/<NUM>/<NUM> may also communicate with computers <NUM>/<NUM> over Internet <NUM> through AP <NUM>.

<FIG> presents components of WLAN device <NUM>, which may be any of AP <NUM> and STAs <NUM>/<NUM>/<NUM>, for use in WLAN <NUM> of <FIG>. WLAN device <NUM> may include a medium access control (MAC) layer and a physical (PHY) layer, according to any set of protocols, techniques, and standards, including protocols and techniques presented herein. In one implementation, as shown in <FIG>, at least one WLAN device may be operated as an access point device, such as AP <NUM>, and the other WLAN devices may be non-AP stations, such as STAs <NUM>/<NUM>/<NUM>. In other implementations, not shown in <FIG>, all WLAN devices may be non-AP STAs in an ad-hoc networking environment. In general, the AP STA and the non-AP STAs may be collectively or individually referred to as stations or station, respectively.

With reference to <FIG>, WLAN device <NUM> includes baseband processor <NUM>, radio frequency (RF) transceiver <NUM>, antenna unit <NUM>, memory <NUM>, input interface unit <NUM>, and output interface unit <NUM>. Baseband processor <NUM> performs baseband signal processing and includes MAC processor <NUM> and PHY processor <NUM>.

In one implementation, MAC processor <NUM> may include MAC software processing unit <NUM> and MAC hardware processing unit <NUM>. Memory <NUM> is a computer readable non-transitory storage device and may store software, such as MAC software, including at least some functions of the MAC layer. Memory <NUM> may further store an operating system and other software and applications for WLAN device <NUM>. MAC software processing unit <NUM> executes the MAC software to implement various functions of the MAC layer, and MAC hardware processing unit <NUM> may implement other functions of the MAC layer in hardware.

In one implementation, PHY processor <NUM> includes receive (RX) signal processing unit <NUM>, which is connected to RF receiver <NUM>, and transmit (TX) signal processing unit <NUM>, which is connected to RF transmitter <NUM>.

TX signal processing unit <NUM> may include an encoder, an interleaver, a mapper, an inverse Fourier transformer (IFT), and a guard interval (GI) inserter. In operation, the encoder encodes input data, the interleaver interleaves the bits of each stream output from the encoder to change the order of bits, the mapper maps the sequence of bits output from the interleaver to constellation points, the IFT converts a block of the constellation points output from the mapper to a time domain block (i.e., a symbol) by using an inverse discrete Fourier transform (IDFT) or an inverse fast Fourier transform (IFFT), and the GI inserter prepends a GI to the symbol for transmission using RF transmitter <NUM> of RF transceiver <NUM>. When MIMO or MU-MIMO is used, RF transmitter <NUM> and the GI inserter may be provided for each transmit chain, in addition to one or more other portions of TX signal processing unit <NUM>.

RX signal processing unit <NUM> may include a decoder, a deinterleaver, a demapper, a Fourier transformer (FT), and a GI remover. In operation, the GI remover receives symbols from RX receiver <NUM> of RF transceiver <NUM>. When MIMO or MU-MIMO is used, RF receiver <NUM> and the GI remover may be provided for each receive chain, in addition to one or more other portions of RX signal processing unit <NUM>. The FT converts the symbol (i.e., the time domain block into a block of the constellation points by using a discrete Fourier transform (DFT) or a fast Fourier transform (FFT). The demapper demaps the constellation points output from the FT, the deinterleaver deinterleaves the bits of each stream output from the demapper, and the decoder decodes the streams output from the deinterleaver to generate input data for framing.

In one implementation, input interface unit <NUM> is configured to receive information from a user, and output interface unit <NUM> is configured to output information to the user. Antenna unit <NUM> may include one or more antennas for wireless transmission and reception of wireless signals. For example, for MIMO or MU-MIMO transmissions, antenna unit <NUM> may include a plurality of antennas.

Turning to <FIG> presents physical layer (PHY) frame <NUM> for use by WLAN <NUM> of <FIG> when operating according to the IEEE <NUM> ac standard. As shown in <FIG>, PHY frame <NUM> includes PHY header <NUM> and PHY payload <NUM>. PHY header <NUM> has a plurality of fields, including L-STF <NUM>, L-LTF <NUM>, L-SIG <NUM>, VHT-SIG-A <NUM>, VHT-STF <NUM>, VHT-LTF <NUM>, VHT-SIG-B <NUM>, and PHY payload <NUM> includes data <NUM>.

L-STF (Legacy Short Training Field) <NUM> and L-LTF (Legacy Long Training Field) each may be represented by two (<NUM>) OFDM symbols that are used to assist WiFi receivers in identifying that an IEEE <NUM> frame is about to start, synchronizing timers, and estimating wireless channels. L-SIG (Legacy Signal Field) <NUM> is used to describe the data rate and length of the frame in bytes, which is used by WiFi receivers to calculate the time duration of the frame's transmission. Any IEEE <NUM> device that is capable of OFDM operation can decode L-STF <NUM>, L-LTF <NUM> and L-SIG <NUM>. PHY header <NUM> starts with L-STF <NUM>, L-LTF <NUM> and L-SIG <NUM>, so that even legacy STAs that do not support the IEEE <NUM>. 11ac standard are able to detect at least legacy parts (L-STF, L-LTF, and L-SIG) of PHY header <NUM>.

VHT-SIG-A (Very High Throughput Signal A) <NUM> and VHT-SIG-B (Very High Throughput Signal B) <NUM>, taken together, describe the included frame attributes, such as the channel width, modulation and coding, PHY payload <NUM>, and whether the frame is a single-user or multi-user frame. The purpose of VHT-SIG-A <NUM> and VHT-SIG-B <NUM> is to help the WiFi receiver decode the data payload, which is done by describing the parameters used for transmission. The IEEE <NUM>. 11ac standard separates the signal into two different parts, called VHT-SIG-A <NUM> and VHT-SIG-B <NUM>. VHT-SIG-A <NUM> is in the part of PHY header <NUM> that is received identically by all receivers. VHT-SIG-B <NUM> is in the part of PHY header <NUM> that is different for each multi-user receiver in case of down-link (DL) MU-MIMO transmission. VHT-SIG-A <NUM> is duplicated for each <NUM> band, so that STAs can identify PHY header <NUM> by only checking the primary <NUM> band. It should be noted that in case of a single user transmission, there is only one target receiver and, as such, there is no separate VHT-SIG-B for another receiver.

VHT-SIG-A <NUM> comes first in PHY header <NUM> and may take on one of two forms depending on whether the transmission is single-user or multi-user. Because VHT-SIG-A <NUM> holds rate information for decoding PHY payload <NUM>, VHT-SIG-A <NUM> is transmitted using a conservative modulation technique. VHT-SIG-B <NUM> may be used to set up the data rate, as well as tune in MIMO reception. Like VHT-SIG-A <NUM>, VHT-SIG-B <NUM> is modulated conservatively to assist receivers in determining the data rate of PHY payload <NUM>. For example, VHT-SIG-A <NUM> and VHT-SIG-B <NUM> may be encoded with the lowest Modulation and Coding Scheme (MCS) level. VHT-SIG-B <NUM> is designed to be transmitted in a single OFDM symbol. As such, VHT-SIG-B <NUM> has slightly different lengths depending on the channel width.

VHT-STF (Very High Throughput Short Training Field) <NUM> serves the same purpose as L-STF <NUM>. Just as the first training fields help a receiver tune in the signal, VHT-STF <NUM> assists the receiver in detecting a repeating pattern and setting receiver gain. VHT-LTF (Very High Throughput Long Training Field) <NUM> consists of a sequence of symbols that set up demodulation of the rest of the frame and also the channel estimation process for beamforming. The number of VHT-LTF <NUM> symbols varies depending on the number of spatial streams carried on the payload.

Data <NUM> holds the higher-layer protocol packet or possibly an aggregate frame containing multiple higher-layer packets. PHY payload <NUM>, which contains data payload <NUM>, immediately follows PHY header <NUM>. Data payload <NUM> is transmitted at the data rate described by PHY header <NUM>.

Although PHY frame <NUM> may have some benefits, PHY frame <NUM> may not be appropriate for OFDMA type resource allocation, as described below. <FIG> presents an OFDMA and MU-MIMO type resource allocation diagram <NUM> for a PHY frame. As shown in <FIG>, four (<NUM>) different users are allocated within one frame duration. Payload for User <NUM> (<NUM>) and Payload for User <NUM> (<NUM>) are allocated in the primary <NUM> band (<NUM>) in an OFDMA manner, which means Payload for User <NUM> (<NUM>) and Payload for User <NUM> (<NUM>) occupy different frequency resources within the primary <NUM> band (<NUM>). Payload User <NUM> (<NUM>) and Payload User <NUM> (<NUM>) are allocated in the secondary <NUM> band (<NUM>) in MU-MIMO manner, which means Payload User <NUM> (<NUM>) and Payload User <NUM> (<NUM>) occupy the same time and frequency resource, but are separated in the spatial domain using multiple antenna techniques. In the example of <FIG>, the PHY payload for each of the four users occupies a different resource, either in a different frequency or spatially separated, but shares at least a portion of the same PHY header. In particular, for uplink transmissions, where multiple different STAs transmit to the same AP, all STAs transmit the same information in at least a portion of the same PHY header, such that the AP can decode the PHY header correctly, since the portion of the PHY header is shared by all STAs.

<FIG> presents an OFDMA type resource allocation diagram <NUM> for a PHY frame. As shown in <FIG>, four (<NUM>) different users are allocated within one frame duration. Payload for User <NUM> (<NUM>) and Payload for User <NUM> (<NUM>) are allocated in the primary <NUM> band (<NUM>) in an OFDMA manner, which means Payload for User <NUM> (<NUM>) and Payload for User <NUM> (<NUM>) occupy different frequency resources within the primary <NUM> band (<NUM>). Payload User <NUM> (<NUM>) and Payload User <NUM> (<NUM>) are allocated in the secondary <NUM> band (<NUM>), also in an OFDMA manner, which means Payload User <NUM> (<NUM>) and Payload User <NUM> (<NUM>) occupy different frequency resources within the secondary <NUM> band (<NUM>).

<FIG> presents an MU-MIMO type resource allocation diagram <NUM> for a PHY frame. As shown in <FIG>, four (<NUM>) different users are allocated within one frame duration. In particular, Payload User <NUM> (<NUM>), Payload User <NUM> (<NUM>), Payload User <NUM> (<NUM>), and Payload User <NUM> (<NUM>) are all allocated in both the primary <NUM> band (<NUM>) and the secondary <NUM> band (<NUM>) in an MU-MIMO manner (i.e., Payload User <NUM> (<NUM>), Payload User <NUM> (<NUM>), Payload User <NUM> (<NUM>), and Payload User <NUM> (<NUM>) occupy the same time and frequency resource, but are separated in spatial domain using multiple antenna techniques). Although shown in relation to a <NUM> channel (i.e., the combined primary <NUM> band (<NUM>) and secondary <NUM> band (<NUM>)), this MU-MIMO technique may be performed in relation to any size channel (e.g., <NUM>, <NUM>, etc.).

Since signals from multiple STAs <NUM>/<NUM>/<NUM> are to be received simultaneously at AP <NUM>, each STA's <NUM>/<NUM>/<NUM> transmission timing has to be synchronized. Also, signals from multiple STAs <NUM>/<NUM>/<NUM> need to be sent within the scheduled resource to avoid packet collision between the STAs <NUM>/<NUM>/<NUM>. Even though different STAs <NUM>/<NUM>/<NUM> use non-overlapping resources, at least part of the PHY header of each STA <NUM>/<NUM>/<NUM> may be sent using the same or an overlapping resource, such as legacy fields of L-STF, L-LTF and L-SIG. As such, the portion of the PHY header sent using the overlapping resource must be the same for all STAs <NUM>/<NUM>/<NUM>, such that the combined signal can be decoded at AP <NUM>. To this end, AP <NUM> sends a scheduling information frame (e.g., a trigger frame) to all STAs <NUM>/<NUM>/<NUM> prior to simultaneous transmissions by the STAs <NUM>/<NUM>/<NUM>. The scheduling information frame may satisfy multiple purposes by setting a reference time for synchronization, providing information on resource allocation, and providing information as to how to encode the portion of the PHY header transmitted using the overlapping resource.

Since AP <NUM> provides STAs <NUM>/<NUM>/<NUM> with scheduling or resource allocation information before STAs' <NUM>/<NUM>/<NUM> uplink (UL) transmissions, the resource allocation information in the PHY header portion of STA's <NUM>/<NUM>/<NUM> UL transmission is redundant and serves no purpose as AP <NUM> already knows the resource allocation information that AP <NUM> originally transmitted to the STAs <NUM>/<NUM>/<NUM>. In fact, STAs <NUM>/<NUM>/<NUM> may not use a different resource allocation than the one indicated by AP <NUM>, since that can cause collisions with UL transmissions from other STAs <NUM>/<NUM>/<NUM>. As such, STAs <NUM>/<NUM>/<NUM> must follow the exact resource allocation provided by AP <NUM>.

Therefore, using PHY frame <NUM> will result in each STA's UL transmission to include the same resource allocation portion that is received from AP <NUM> and which is already known by STA <NUM>/<NUM>/<NUM>. Thus, as noted above, including the resource allocation information in the PHY header of each STA's <NUM>/<NUM>/<NUM> UL transmission will increase signaling overhead and is redundant. In one implementation of the present disclosure, the PHY header includes at least two signaling (SIG) fields, which are encoded separately. The first encoded SIG field includes a resource allocation indication (RAI) to indicate whether or not the other encoded SIG field(s) includes resource allocation information. STA <NUM>/<NUM>/<NUM> does not include the resource allocation information in the PHY header if a receiver of a frame, e.g. AP <NUM>, has access to the resource allocation information, such as UL OFDMA and single user full band transmissions. However, STA <NUM>/<NUM>/<NUM> includes the resource allocation information in the PHY header if the receiver of the frame does not have access to the resource allocation information, such as DL OFDMA or single user partial band transmissions. For example, in case of UL MU simultaneous transmission, every STA that participates in the transmission needs to set the RAI in the first encoded signaling (SIG) field to indicate that resource allocation information is not included in the other encoded SIG field(s). In another implementation, the PHY header includes a single SIG field, such that the other encoded SIG fields are completely omitted if the receiver of the frame has access to all information that would be included within these omitted SIG field(s).

<FIG> presents PHY frame <NUM> having PHY header <NUM> with four (<NUM>) possible SIG fields <NUM>/<NUM>/<NUM>/<NUM> and HE-TF-B field <NUM>, according to one implementation of the present disclosure. As shown in <FIG>, SIG fields include L-SIG <NUM>, HE-SIG-A <NUM>, HE-SIG-B <NUM> and HE-SIG-C <NUM>, where HE stands for high efficiency. In the implementation of <FIG>, HE-SIG-A <NUM> includes an indication to indicate to a receiver whether HE-SIG-B <NUM> is included in PHY header <NUM> or not, where HE-SIG-B <NUM> includes resource allocation information. As such, HE-SIG-B <NUM> is included in PHY header <NUM> only when HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> exists in PHY header <NUM>. As shown in <FIG>, PHY header <NUM> also includes L-STF/L-LTF <NUM> and L-SIG <NUM>, which may be the same as L-STF <NUM>, L-LTF <NUM> and L-SIG <NUM>, respectively, in PHY header <NUM> of <FIG>.

In the implementation of <FIG>, HE-SIG-A <NUM> may include information relating to proper channel deferral and overall frame format information, which may include channel bandwidth, basic service set (BSS) ID, BSS Color, group ID and/or partial AID/BSSID of target STAs, GI (Guard Interval), and frequency domain tone spacing in the event that there is more than one frequency domain tone spacing used in the frame. HE-SIG-A <NUM> may also include an indication as to whether HE-SIG-B <NUM> exists in PHY header <NUM>. In one implementation, HE-SIG-B <NUM> may have a variable size and HE-SIG-A <NUM> may indicate a length of HE-SIG-B <NUM>. For example, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is zero, PHY header <NUM> will not include HE-SIG-B <NUM> (i.e., this length serves as the indication that HE-SIG-B <NUM> is not present in the frame). However, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is a number other than zero (e.g., greater than zero), PHY header <NUM> will include HE-SIG-B <NUM> having a length indicated by the number provided in HE-SIG-A <NUM>. In another implementation, HE-SIG-B <NUM> may have a fixed, pre-established length and a single bit in HE-SIG-A <NUM> may indicate whether or not PHY header <NUM> includes HE-SIG-B <NUM>.

HE-SIG-A <NUM> may be encoded in a predetermined channel bandwidth, e.g. <NUM>, and may be duplicated at every predetermined channel bandwidth that the frame occupies. Also, channel estimation and decoding of HE-SIG-A <NUM> may rely on L-STF/L-LTF <NUM>. HE-SIG-B <NUM> may include the resource allocation information for each scheduled STA, which may include mapping information between allocated sub-channel and corresponding STA. HE-SIG-B <NUM> may be encoded using an entire bandwidth that is indicated in HE-SIG-A <NUM>. In some embodiments, HE-SIG-B may be repeated across separate sub-bands of the entire bandwidth. For example, duplicated copies of HE-SIG-B may be repeated in <NUM> segments of the full channel bandwidth. In another example, HE-SIG-B may be partially copied in a set of sub-bands. For example, a first <NUM> sub-band may include a first HE-SIG-B, a second <NUM> sub-band may include a second HE-SIG-B, a third <NUM> sub-band may include the first HE-SIG-B, a fourth <NUM> sub-band may include the second HE-SIG-B, etc..

For proper decoding of HE-SIG-B <NUM>, PHY header <NUM> includes HE-TF-B <NUM>, which refers to STF/LTF for HE-SIG-B, and appears before HE-SIG-B <NUM>, as shown in <FIG>. In the event that PHY header <NUM> does not include HE-SIG-B <NUM>, as indicated by HE-SIG-A <NUM>, HE-TF-B <NUM> will also not be included in PHY header <NUM>.

HE-SIG-C <NUM> may include per-STA frame information, such as MCS level, coding scheme, and use of Space-time block coding (STBC). In one implementation, HE-SIG-C <NUM> may be encoded per each allocated sub-channel, and may utilize HE-STF/LTF <NUM> for channel estimation and decoding.

<FIG> presents PHY frame <NUM> having PHY header <NUM> with four (<NUM>) possible SIG fields <NUM>/<NUM>/<NUM>/<NUM>, according to one implementation of the present disclosure. As shown in <FIG>, SIG fields include L-SIG <NUM>, HE-SIG-A <NUM>, HE-SIG-B <NUM>, and HE-SIG-C <NUM>. In the implementation of <FIG>, HE-SIG-A <NUM> includes an indication to a receiver whether HE-SIG-B <NUM> is included in PHY header <NUM> or not, where HE-SIG-B <NUM> includes resource allocation information. As such, HE-SIG-B <NUM> is included in PHY header <NUM> only when HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> exists in PHY header <NUM>. As shown in <FIG>, PHY header <NUM> also includes L-STF/L-LTF <NUM> and L-SIG <NUM>, which are the same as L-STF <NUM>, L-LTF <NUM>, and L-SIG <NUM> in PHY header <NUM> of <FIG>.

In the implementation of <FIG>, HE-SIG-A <NUM> may include information relating to proper channel deferral, and overall frame format information, which may include channel bandwidth, basic service set (BSS) ID, BSS Color, group ID and/or partial AID/BSSID of target STAs, GI (Guard Interval), and frequency domain tone spacing in the event that there is more than one frequency domain tone spacing used in the frame. HE-SIG-A <NUM> may also include an indication as to whether HE-SIG-B <NUM> exists in PHY header <NUM>. In one implementation, HE-SIG-B <NUM> may have a variable size and HE-SIG-A <NUM> may indicate a length of HE-SIG-B <NUM>. For example, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is zero, HE-SIG-B <NUM> will not be included in PHY header <NUM>. However, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is a number other than zero, PHY header <NUM> will include HE-SIG-B <NUM> of the length indicated by the number in HE-SIG-A <NUM>. In another implementation, HE-SIG-B <NUM> may have a fixed, pre-established length and a single bit in HE-SIG-A <NUM> may indicate whether or not PHY header <NUM> includes HE-SIG-B <NUM>.

HE-SIG-A <NUM> is encoded in a predetermined channel bandwidth, e.g. <NUM>, and is duplicated at every predetermined channel bandwidth that the frame occupies. Also, channel estimation and decoding of HE-SIG-A <NUM> may rely on L-STF/L-LTF <NUM>. HE-SIG-B <NUM> has the resource allocation information for each scheduled STA, which may include mapping information between allocated sub-channel and a corresponding STA. HE-SIG-B <NUM> may be encoded using an entire bandwidth that is indicated in HE-SIG-A <NUM> or may be encoded across multiple sub-bands of the channel in duplicated, non-duplicated, or partially duplicated parts as noted above. Unlike the implementation of <FIG>, PHY header <NUM> of <FIG> does not include a HE-TF-B field and, thus, there is less overhead in PHY header <NUM> compared to PHY header <NUM>. In the implementation of <FIG>, for proper decoding of HE-SIG-B <NUM> with the absence of a HE-TF-B field, the receiver buffers the entire channel bandwidth of the received L-LTF <NUM> and after identifying the bandwidth of the frame, the receiver reutilizes L-LTF <NUM> information for the whole occupied bandwidth for decoding HE-SIG-B <NUM>.

HE-SIG-C <NUM> may include per-STA frame information, such as MCS level, coding scheme, and/or use of STBC. In one implementation, HE-SIG-C <NUM> may be encoded per each allocated sub-channel and may utilize HE-STF/LTF <NUM> for channel estimation and decoding.

<FIG> presents PHY frame <NUM> having PHY header <NUM> with three (<NUM>) SIG fields <NUM>/<NUM>/<NUM> and HE-TF-B <NUM> field, according to one implementation of the present disclosure. As shown in <FIG>, SIG fields include L-SIG <NUM>, HE-SIG-A <NUM>, and HE-SIG-B <NUM>. In the implementation of <FIG>, HE-SIG-A <NUM> includes an indication to a receiver whether or not HE-SIG-B <NUM> includes resource allocation information. As such, resource allocation information is included in HE-SIG-B <NUM> only when HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> includes such information. As shown in <FIG>, PHY header <NUM> also includes L-STF/L-LTF <NUM> and L-SIG <NUM>, which are the same as L-STF <NUM>, L-LTF <NUM> and L-SIG <NUM> in PHY header <NUM> of <FIG>.

In the implementation of <FIG>, HE-SIG-A <NUM> may include information relating to proper channel deferral, and overall frame format information, which may include channel bandwidth, basic service set (BSS) ID, BSS Color, group ID and/or partial AID/BSSID of target STAs, GI (Guard Interval), and frequency domain tone spacing in the event that there is more than one frequency domain tone spacing used in the frame. HE-SIG-A <NUM> may also include an indication if HE-SIG-B <NUM> is present in the PHY header <NUM> or includes resource allocation information.

HE-SIG-A <NUM> may be encoded in a predetermined channel bandwidth, e.g. <NUM>, and may be duplicated at every predetermined channel bandwidth that the frame occupies. Also, channel estimation and decoding of HE-SIG-A <NUM> may rely on L-STF/L-LTF <NUM>. HE-SIG-B <NUM> may include per-STA frame information, such as MCS level, coding scheme, and/or use of STBC. If HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> includes resource allocation information, HE-SIG-B <NUM> field will have resource allocation information for each scheduled STA, which may include mapping information between allocated sub-channel and a corresponding STA. HE-SIG-B <NUM> may be encoded using an entire bandwidth that is indicated in HE-SIG-A <NUM> or may be encoded across multiple sub-bands of the channel in duplicated, non-duplicated, or partially duplicated parts as noted above. For proper decoding of HE-SIG-B <NUM>, PHY header <NUM> may include HE-TF-B <NUM>, which appears before HE-SIG-B <NUM>, as shown in <FIG>.

As shown in <FIG>, PHY header <NUM> may also include L-STF/L-LTF <NUM> and L-SIG <NUM>, which are the same as L-STF <NUM>, L-LTF <NUM> and L-SIG <NUM> in PHY header 301of <FIG>. HE-SIG-A <NUM> may include information relating to proper channel deferral and overall frame format information, which may include channel bandwidth, basic service set (BSS) ID, BSS Color, group ID and/or partial AID/BSSID of target STAs, GI (Guard Interval), and frequency domain tone spacing in the event that there is more than one frequency domain tone spacing used in the frame. HE-SIG-A <NUM> may also include an indication if HE-SIG-B <NUM> is included in PHY header <NUM>. In one implementation, HE-SIG-B <NUM> may have a variable size and HE-SIG-A <NUM> may indicate a length of HE-SIG-B <NUM>. For example, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is zero, PHY header <NUM> will not include HE-SIG-B <NUM>. However, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is a number other than zero, PHY header <NUM> will include HE-SIG-B <NUM> of the length indicated.

HE-SIG-A <NUM> may be encoded in a predetermined channel bandwidth, e.g. <NUM>, and may be duplicated at every predetermined channel bandwidth that the frame occupies. Also, channel estimation and decoding of HE-SIG-A <NUM> may rely on L-STF/L-LTF <NUM>. HE-SIG-B <NUM> may include per-STA frame information, such as MCS level, coding scheme, and/or use of STBC. HE-SIG-B <NUM> may have resource allocation information for each scheduled STA, which may include mapping information between allocated sub-channel and corresponding STA. HE-SIG-B <NUM> may be encoded using an entire bandwidth that is indicated in HE-SIG-A <NUM> or may be encoded across multiple sub-bands of the channel in duplicated, non-duplicated, or partially duplicated parts as noted above. For proper decoding of HE-SIG-B <NUM>, PHY header <NUM> includes HE-TF-B <NUM>, which appears before HE-SIG-B <NUM>, as shown in <FIG>. In the event that PHY header <NUM> does not include HE-SIG-B <NUM>, as indicated by HE-SIG-A <NUM>, HE-TF-B <NUM> will also not be included in PHY header <NUM>.

<FIG> presents PHY frame <NUM> having PHY header <NUM> according to one implementation of the present disclosure, where HE-SIG-A <NUM> may include an indication to a receiver that a HE-SIG-B field is not included in PHY header <NUM>. As such, resource allocation information is included only when HE-SIG-A <NUM> (or HE-SIG-A <NUM> of <FIG>) indicates that the HE-SIG-B is included in PHY header <NUM> (or <NUM>). In <FIG>, L-STF/L-LTF <NUM>, L-SIG <NUM>, HE-SIG-A <NUM>, HE-STF/LTF <NUM> and Data Payload <NUM> may correspond to L-STF/L-LTF <NUM>, L-SIG <NUM>, HE-SIG-A <NUM>, HE-STF/LTF <NUM> and Data Payload <NUM> of <FIG>, respectively.

<FIG> presents PHY frame <NUM> having PHY header <NUM> with three (<NUM>) SIG fields <NUM>/<NUM>/<NUM>, according to one implementation of the present disclosure. As shown in <FIG>, SIG fields include L-SIG <NUM>, HE-SIG-A <NUM>, and HE-SIG-B <NUM>. In the implementation of <FIG>, HE-SIG-A <NUM> includes an indication to a receiver whether or not HE-SIG-B <NUM> includes resource allocation information. As such, resource allocation information is included in HE-SIG-B <NUM> only when HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> includes such information. As shown in <FIG>, PHY header <NUM> also includes L-STF/L-LTF <NUM> and L-SIG <NUM>, which are the same as L-STF <NUM>, L-LTF <NUM>, and L-SIG <NUM> in PHY header <NUM> of <FIG>.

Unlike the implementation of <FIG>, PHY header <NUM> of <FIG> may not include a HE-TF-B field and, thus, there is less overhead in PHY header <NUM> compared to PHY header <NUM>. In the implementation of <FIG>, for proper decoding of HE-SIG-B <NUM> with a HE-TF-B field absent, the receiver buffers the entire channel bandwidth of the received L-LTF <NUM>, and after identifying the bandwidth of the frame, the receiver reutilizes L-LTF <NUM> information for the whole occupied bandwidth for decoding HE-SIG-B <NUM>.

In the implementation of <FIG>, HE-SIG-A <NUM> may include information relating to proper channel deferral, and overall frame format information, which may include channel bandwidth, basic service set (BSS) ID, BSS Color, group ID and/or partial AID/BSSID of target STAs, GI (Guard Interval), and frequency domain tone spacing in the event that there is more than one frequency domain tone spacing used in the frame. HE-SIG-A <NUM> may also include an indication if HE-SIG-B <NUM> includes resource allocation information and may also indicate the size of HE-SIG-B <NUM>.

HE-SIG-A <NUM> is encoded in a predetermined channel bandwidth, e.g. <NUM>, and is duplicated at every predetermined channel bandwidth that the frame occupies. Also, channel estimation and decoding of HE-SIG-A <NUM> may rely on L-STF/L-LTF <NUM>. HE-SIG-B <NUM> includes per-STA frame information, such as MCS level, coding scheme, and/or use of STBC. If HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> includes resource allocation information, HE-SIG-B <NUM> will have resource allocation information for each scheduled STA, which may include mapping information between allocated sub-channel and corresponding STA. HE-SIG-B <NUM> may be encoded using an entire bandwidth that is indicated in HE-SIG-A <NUM> or may be encoded across multiple sub-bands of the channel in duplicated, non-duplicated, or partially duplicated parts as noted above. For proper decoding of HE-SIG-B <NUM>, the receiver needs to buffer L-LTF <NUM> value for the entire channel bandwidth of the received frame, as discussed above.

In another implementation of <FIG>, HE-SIG-A <NUM> includes an indication to a receiver whether HE-SIG-B <NUM> is included in PHY header <NUM> or not, where HE-SIG-B <NUM> includes resource allocation information. As such, resource allocation information is included only when HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> is included. As shown in <FIG>, PHY header <NUM> also includes L-STF/L-LTF <NUM> and L-SIG <NUM>, which are the same as L-STF <NUM>, L-LTF <NUM> and L-SIG <NUM> in PHY header <NUM> of <FIG>.

In this implementation of <FIG>, HE-SIG-A <NUM> may include information relating to proper channel deferral and overall frame format information, which may include channel bandwidth, basic service set (BSS) ID, group ID and/or partial AID/BSSID of target STAs, GI (Guard Interval), and frequency domain tone spacing in the event that there is more than one frequency domain tone spacing used in the frame. HE-SIG-A <NUM> may also include an indication if HE-SIG-B <NUM> is included in PHY header <NUM>, and/or may also indicate the size of HE-SIG-B <NUM>. In one implementation, HE-SIG-B <NUM> may have a variable size, and HE-SIG-A <NUM> may indicate a length of HE-SIG-B <NUM>. For example, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is zero, HE-SIG-B <NUM> is not included in PHY header <NUM>. However, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is a number other than zero, PHY header <NUM> will include HE-SIG-B <NUM> of the length indicated.

HE-SIG-A <NUM> may be encoded in a predetermined channel bandwidth, e.g. <NUM>, and is duplicated at every predetermined channel bandwidth that the frame occupies. Also, channel estimation and decoding of HE-SIG-A <NUM> may rely on L-STF/L-LTF <NUM>. HE-SIG-B <NUM> includes per-STA frame information, such as MCS level, coding scheme, and use of STBC. HE-SIG-B <NUM> may also have resource allocation information for each scheduled STA, which may include mapping information between allocated sub-channel and corresponding STA. HE-SIG-B <NUM> may be encoded using an entire bandwidth that is indicated in HE-SIG-A <NUM> or may be encoded across multiple sub-bands of the channel in duplicated, non-duplicated, or partially duplicated parts as noted above. For proper decoding of HE-SIG-B <NUM>, the receiver needs to buffer L-LTF <NUM> value for the entire channel bandwidth of the received frame, as discussed above.

<FIG> presents PHY frame <NUM> having PHY header <NUM> with four (<NUM>) possible SIG fields <NUM>/<NUM>/<NUM>/<NUM> and common HE-STF/LTF1 <NUM> field, according to one implementation of the present disclosure.

As shown in <FIG>, SIG fields include L-SIG <NUM>, HE-SIG-A <NUM>, HE-SIG-B <NUM>, and HE-SIG-C <NUM>. In the implementation of <FIG>, HE-SIG-A <NUM> includes an indication to a receiver whether HE-SIG-B <NUM> is included in PHY header <NUM> or not, where HE-SIG-B <NUM> includes resource allocation information. As such, HE-SIG-B <NUM> is included in PHY header <NUM> only when HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> exists in PHY header <NUM>. As shown in <FIG>, PHY header <NUM> also includes L-STF/L-LTF <NUM> and L-SIG <NUM>, which are the same as L-STF <NUM>, L-LTF <NUM> and L-SIG <NUM> in PHY header <NUM> of <FIG>. PHY header <NUM> also includes HE-STF/LTF1 <NUM> for estimating the channel and decoding of HE-SIG-B <NUM>, HE-SIG-C <NUM>, and data payload <NUM> for each allocated user's stream. In case the data payload <NUM> is encoded with the number of space-time streams more than one, additional HE-LTF2 to HE-LTF2n <NUM> would follow HE-SIG-C <NUM>.

In the implementation of <FIG>, HE-SIG-A <NUM> may include information relating to proper channel deferral and overall frame format information, which may include channel bandwidth, basic service set (BSS) ID, BSS Color, group ID and/or partial AID/BSSID of target STAs, GI (Guard Interval), and frequency domain tone spacing in the event that there is more than one frequency domain tone spacing used in the frame. HE-SIG-A <NUM> may also include an indication as to whether HE-SIG-B <NUM> exists in PHY header <NUM>. In one implementation, HE-SIG-B <NUM> may have a variable size and HE-SIG-A <NUM> may indicate a length of HE-SIG-B <NUM>. For example, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is zero, HE-SIG-B <NUM> is not included in PHY header <NUM>. However, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is a number other than zero, PHY header <NUM> will include HE-SIG-B <NUM> of the length indicated. In another implementation, HE-SIG-B <NUM> may have a fixed length and a single bit in HE-SIG-A <NUM> may indicate whether or not PHY header <NUM> includes HE-SIG-B <NUM>.

HE-SIG-A <NUM> is encoded in a predetermined channel bandwidth, e.g. <NUM>, and is duplicated at every predetermined channel bandwidth that the frame occupies. Also, channel estimation and decoding of HE-SIG-A <NUM> may rely on L-STF/L-LTF <NUM>. HE-SIG-B <NUM> has the resource allocation information for each scheduled STA, which may include mapping information between allocated sub-channel and corresponding STA. HE-SIG-B <NUM> may be encoded using an entire bandwidth that is indicated in HE-SIG-A <NUM> or may be encoded across multiple sub-bands of the channel in duplicated, non-duplicated, or partially duplicated parts as noted above.

HE-SIG-C <NUM> may include per-STA frame information, such as MCS level, coding scheme, and/or use of STBC. In one implementation, HE-SIG-C <NUM> may be encoded per each allocated sub-channel and utilizes HE-STF/LTF1 <NUM> for channel estimation and decoding.

For proper decoding of HE-SIG-B <NUM>, HE-SIG-C <NUM> and data payload, HE-STF/LTF1 <NUM> is included in PHY header <NUM> before HE-SIG-B <NUM>. In case the data payload is encoded with the number of space-time streams more than one, additional HE-LTF2 to HE-LTF2-n <NUM> would follow HE-SIG-C <NUM>. In case data payload of different users is encoded with different number of space-time streams, the number of HE-LTF2 <NUM> fields for each different sub-channel can be different depending on the actual number of space-time streams allocated in each sub-channel. If frequency domain tone spacing of data payload is different from that of legacy fields, for example legacy field is using <NUM> FFT in <NUM> bandwidth (i.e., a DFT period of <NUM> and subcarrier spacing of <NUM>) and data payload is using <NUM> FFT in <NUM> bandwidth (i.e., a DFT period of <NUM> and subcarrier spacing of <NUM>), frequency domain tone spacing of data payload is applied from HE-STF/LTF1 <NUM> through the end of the frame.

<FIG> presents PHY frame <NUM> having PHY header <NUM> with three (<NUM>) SIG fields <NUM>/<NUM>/<NUM> and common HE-STF/LTF1 <NUM> field, according to one implementation of the present disclosure. As shown in <FIG>, SIG fields include L-SIG <NUM>, HE-SIG-A <NUM> and HE-SIG-B <NUM>. In the implementation of <FIG>, HE-SIG-A <NUM> includes an indication to a receiver whether or not HE-SIG-B <NUM> includes resource allocation information. As such, resource allocation information is included in HE-SIG-B <NUM> only when HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> includes such information. As shown in <FIG>, PHY header <NUM> also includes L-STF/L-LTF <NUM> and L-SIG <NUM>, which are the same as L-STF <NUM>, L-LTF <NUM> and L-SIG <NUM> in PHY header <NUM> of <FIG>. PHY header <NUM> also includes HE-STF/LTF1 <NUM> for estimating channel and decoding of HE-SIG-B <NUM> and data payload for each allocated user's stream. In case the data payload is encoded with a number of space-time streams more than one, additional HE-LTF2 to HE-LTF2-n fields <NUM> would follow HE-SIG-B <NUM>.

In the implementation of <FIG>, HE-SIG-A <NUM> may include information relating to proper channel deferral and overall frame format information, which may include channel bandwidth, basic service set (BSS) ID, BSS Color, group ID and/or partial AID/BSSID of target STAs, GI (Guard Interval), and frequency domain tone spacing in the event that there is more than one frequency domain tone spacing used in the frame. HE-SIG-A <NUM> may also include an indication if HE-SIG-B <NUM> includes resource allocation information, and may also indicate the size of HE-SIG-B <NUM>.

HE-SIG-A <NUM> is encoded in a predetermined channel bandwidth, e.g. <NUM> and is duplicated at every predetermined channel bandwidth that the frame occupies. Also, channel estimation and decoding of HE-SIG-A <NUM> may rely on L-STF/L-LTF <NUM>. HE-SIG-B <NUM> may include per-STA frame information, such as MCS level, coding scheme, and/or use of STBC. If HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> includes resource allocation information, HE-SIG-B <NUM> field will have resource allocation information for each scheduled STA, which may include mapping information between allocated sub-channel and corresponding STA. HE-SIG-B <NUM> may be encoded using an entire bandwidth that is indicated in HE-SIG-A <NUM> or may be encoded across multiple sub-bands of the channel in duplicated, non-duplicated, or partially duplicated parts as noted above.

For proper decoding of HE-SIG-B <NUM> and data payload, HE-STF/LTF1 <NUM> is included in PHY header <NUM> before HE-SIG-B <NUM>. In case the data payload is encoded with the number of space-time streams more than one, additional HE-LTF2 to HE-LTF2-n <NUM> would follow HE-SIG-B <NUM>. If frequency domain tone spacing of data payload is different from that of legacy fields, for example legacy field is using <NUM> FFT in <NUM> bandwidth (i.e., a DFT period of <NUM> and subcarrier spacing of <NUM>) and data payload is using <NUM> FFT in <NUM> bandwidth (i.e., a DFT period of <NUM> and subcarrier spacing of <NUM>), frequency domain tone spacing of data payload is applied from HE-STF/LTF1 <NUM> through the end of the frame.

In another implementation that is shown in <FIG>, HE-SIG-A <NUM> may include an indication to a receiver whether HE-SIG-B <NUM> is included in PHY header <NUM> or not, where HE-SIG-B <NUM> includes resource allocation information. As such, resource allocation information is included in HE-SIG-B <NUM> only when HE-SIG-A <NUM> indicates that HE-SIG-B <NUM> is included in PHY header <NUM>. As shown in <FIG>, PHY header <NUM> also includes L-STF/L-LTF <NUM> and L-SIG <NUM>, which are the same as L-STF <NUM>, L-LTF <NUM> and L-SIG <NUM> in PHY header <NUM> of <FIG>. PHY header <NUM> also includes HE-STF/LTF1 <NUM> for estimating channel and decoding of HE-SIG-B <NUM> and data payload for each allocated user's stream. In case the data payload is encoded with a number of space-time streams more than one, additional HE-LTF2 to HE-LTF2-n fields <NUM> would follow HE-SIG-B <NUM>.

In this implementation of <FIG>, HE-SIG-A <NUM> may include information relating to proper channel deferral, and overall frame format information, which may include channel bandwidth, basic service set (BSS) ID, BSS Color, group ID and/or partial AID/BSSID of target STAs, GI (Guard Interval), and frequency domain tone spacing in the event that there is more than one frequency domain tone spacing used in the frame. HE-SIG-A <NUM> may also include an indication as to whether HE-SIG-B <NUM> exists in PHY header <NUM>. In one implementation, HE-SIG-B <NUM> may have a variable size, and HE-SIG-A <NUM> may indicate a length of HE-SIG-B <NUM>. For example, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is zero, PHY header <NUM> will not include HE-SIG-B <NUM>. However, if HE-SIG-A <NUM> indicates that the length of HE-SIG-B <NUM> is a number other than zero, PHY header <NUM> will include HE-SIG-B <NUM> of the length indicated.

HE-SIG-A <NUM> may be encoded in a predetermined channel bandwidth, e.g. <NUM>, and may be duplicated at every predetermined channel bandwidth that the frame occupies. Also, channel estimation and decoding of HE-SIG-A <NUM> may rely on L-STF/L-LTF <NUM>. HE-SIG-B <NUM> may include per-STA frame information, such as MCS level, coding scheme, and/or use of STBC. HE-SIG-B <NUM> field may also have resource allocation information for each scheduled STA, which may include mapping information between allocated sub-channel and corresponding STA. HE-SIG-B <NUM> may be encoded using an entire bandwidth that is indicated in HE-SIG-A <NUM> or may be encoded across multiple sub-bands of the channel in duplicated, non-duplicated, or partially duplicated parts as noted above.

For proper decoding of HE-SIG-B <NUM> and data payload, HE-STF/LTF1 <NUM> may be included in PHY header <NUM> before HE-SIG-B <NUM>. In case the data payload is encoded with the number of space-time streams more than one, additional HE-LTF2 to HE-LTF2-n <NUM> would follow HE-SIG-B <NUM>. If frequency domain tone spacing of data payload is different from that of legacy fields, for example legacy field is using <NUM> FFT in <NUM> bandwidth (i.e., a DFT period of <NUM> and subcarrier spacing of <NUM>) and data payload is using <NUM> FFT in <NUM> bandwidth (i.e., a DFT period of <NUM> and subcarrier spacing of <NUM>), frequency domain tone spacing of data payload is applied from HE-STF/LTF1 <NUM> through the end of the frame.

<FIG> presents a flow diagram of method <NUM> for use by a wireless device in WLAN <NUM> of <FIG>, according to one implementation of the present disclosure. For example, method <NUM> may be performed by AP <NUM> or STA <NUM>. Method <NUM> will be described below in relation to AP <NUM> for simplicity, but it is understood that method <NUM> may be similarly performed by another wireless device in WLAN <NUM>.

As discussed above and shown in <FIG>, AP <NUM> may include baseband processor <NUM> and memory <NUM>, which may be used to perform one or more of the operations of method <NUM>. In one embodiment, method <NUM> may commence at operation <NUM>. At operation <NUM>, AP <NUM> may determine whether resource allocation/scheduling information should or needs to be included in a generated frame that will be transmitted to one or more recipients by AP <NUM>. In one embodiment, AP <NUM> may determine at operation <NUM> that the resource allocation/scheduling information is unnecessary for the generated frame when the generated frame is intended to be sent to a single recipient in a full-band transmission (e.g., a single user (SU) full band transmission). In this case of a single recipient/user full band transmission, resource allocation/scheduling information provided would be unnecessary as the channel will not be divided into separate sub-channel/resource units. When method <NUM> will be performed by STA <NUM>, the resource allocation/scheduling information may be unnecessary when the generated frame will be transmitted as a response to a trigger frame. In the case of a response to a trigger frame, resource allocation/scheduling information does not need to be retransmitted back to the sender of the trigger frame as the trigger frame included this information. Accordingly, the recipient of the generated frame would already be aware of this reallocation information. Conversely, resource allocation/scheduling information may be necessary when the generated frame is a downlink multi-user transmission (e.g., an OFDMA transmission from AP <NUM> to two or more STAs <NUM>/<NUM>/<NUM>). In this situation, each STA needs to know sub-channel assignment to analyze the generated frame, which would be provided in resource allocation/scheduling information.

In response to determining that the resource allocation/scheduling information is needed in the generated frame, operation <NUM> may set an indication in a first signaling field of the generated frame that a second signaling field containing the resource allocation/scheduling information is present in the generated frame. In one implementation, this indication may be a single bit that indicates the presence of the second signaling field, while in other implementations the indication may be a series of bits that indicates a length of the second signaling field. For example, in the latter case, the first signaling field may record a length of zero when the second signaling field is not present and a length greater than zero when the second signaling field is present.

In some embodiments, the generated frame may be similar or identical to one or more of frames <NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM> described above and may include a header similar to one or more of headers <NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM>. For example, the first signaling field may be HE-SIG-A while the second signaling field is HE-SIG-B.

Following setting the indication of the presence of the second signaling field and corresponding presence of resource allocation/scheduling information, operation <NUM> may add the second signaling field to the frame. As noted above, the second signaling field may include resource allocation/scheduling information, including mapping of STAs to particular sub-bands of a channel.

Returning to operation <NUM>, upon determining that resource allocation/scheduling information is not needed in the frame, operation <NUM> may reflect this decision in the first signaling field. As noted above, when method <NUM> is being performed by STA <NUM> and the generated frame is a response to a trigger frame, the frame may not require resource allocation/scheduling information. In particular, since the trigger frame already included resource allocation/scheduling information, the generated frame does not need to convey this information to the original sender (e.g., AP <NUM>).

Although described in relation to first and second signaling fields, the generated frame may include one or more additional fields, such as L-STF/LTF <NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM> and L-SIG <NUM>/<NUM>/<NUM>/<NUM>/<NUM>/ <NUM>/<NUM>, HE-STF/LTF <NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM> and HE-SIG-C <NUM>/<NUM>/<NUM>, and also data payload <NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM>/<NUM>. Following generation of the generated frame, AP <NUM> may transmit the generated frame at operation <NUM> to one or more wireless devices (e.g., STAs <NUM>/<NUM>/<NUM>).

Turning now to <FIG>, method <NUM> will be described. Method <NUM> may be performed by a wireless device operating in WLAN <NUM> shown in <FIG>. For example, method <NUM> may be performed by AP <NUM> or STA <NUM>. As described herein, method <NUM> will be performed by STA <NUM> for simplicity of description. As discussed above and shown in <FIG>, STA <NUM> may include baseband processor <NUM> and memory <NUM>, which may be used to perform one or more of the operations of method <NUM>.

Method <NUM> may commence at operation <NUM> with STA <NUM> receiving a frame, which may have been generated by AP <NUM> using method <NUM>. The frame may include a first signaling field and optionally a second signaling field, which contains resource allocation information for multiple user transmissions. In some embodiments, the received frame may also be received simultaneously by multiple other STAs (e.g., STA <NUM> and <NUM>).

At operation <NUM>, STA <NUM> may process the received frame. Processing the frame may include analyzing a first signaling field of the first frame to determine the presence of a second signaling field. As described above in relation to method <NUM>, the first signaling field may include an indication as to whether a second signaling field containing resource allocation information is present in the received frame. This indication may be a single bit or a set of bits, which may be used to indicate the length of the second signaling field.

Upon determining that the second signaling field is present and/or includes resource allocation information, STA <NUM> may extract resource allocation information from the second signaling field of the received frame at operation <NUM>. STA <NUM> may thereafter utilize the extracted information to process the frame at operation <NUM>. For example, STA <NUM> may determine a sub-band/sub-channel in the frame that is devoted/assigned/mapped to STA <NUM> based on the extracted resource allocation information from the frame. For example, the resource allocation information may indicate that a <NUM> channel, upon which the received frame was transmitted, has been divided into two sub-channels/sub-bands: a first sub-channel/sub-band mapped to STA <NUM> and a second sub-channel/sub-band mapped to STA <NUM>. In this example, STA <NUM> may analyze the resource scheduling information and determine that the first sub-channel/sub-band is mapped to STA <NUM>. Based on this, STA <NUM> may process a data payload of the frame transmitted within the first sub-channel/sub-band.

Alternatively, upon determining that the second signaling field is not present and/or the received frame does not include resource allocation information, STA <NUM> may process the frame using previously known resource allocation information at operation <NUM> or otherwise without resource allocation information from the received frame (e.g., process the frame a single user, full band transmission).

From the above description it is manifest that various techniques can be used for implementing the concepts described in the present application without departing from the scope of those concepts. Moreover, while the concepts have been described with specific reference to certain implementations, a person of ordinary skill in the art would recognize that changes can be made in form and detail without departing from the scope of those concepts. As such, the described implementations are to be considered in all respects as illustrative and not restrictive. It should also be understood that the present application is not limited to the particular implementations described above, but many rearrangements, modifications, and substitutions are possible without departing from the scope of the present disclosure.

As noted above, an embodiment of the invention may be an apparatus (e.g., an access point, a client station, or another network or computing device) that includes one or more hardware and software logic structure for performing one or more of the operations described herein. For example, the apparatus may include a memory unit, which stores instructions that may be executed by a hardware processor installed in the apparatus. The apparatus may also include one or more other hardware or software elements, including a network interface, a display device, etc..

Claim 1:
A method for performing wireless communications, the method comprising:
generating, by a first wireless device, a frame for transmission to a second wireless device, wherein generating the frame includes:
adding a first signaling field to the frame, wherein the first signaling field assists a second wireless device that receives the frame to process the frame,
determining (<NUM>) to not include a second signaling field in the frame when the frame is transmitted as a single user transmission to the second wireless device, and
determining (<NUM>) to include and adding a second signaling field to the frame when the frame is transmitted as a multi-user transmission; and
transmitting (<NUM>), by the first wireless device, the frame to the second wireless device over a wireless channel.