Abstract: Embodiments of the present invention provide a method and device for multi-AP beamforming (e.g., nulling) and spatial reuse to mitigate interference and improve the performance of MAP wireless networks. According to one embodiment, multiple APs agree to collaborate in multi-AP beamforming, transmissions of received PDDUs are measured to determine interference information, the APS generate interference maps, and the APs perform joint and Multi-AP beamforming in a first and second BSS to avoid/mitigate interference of the MAP wireless network. An RTS and CTS frame exchange sequence can be performed prior to Multi-AP beamforming between BSSs using a flag/indicator in the RTS frame to indicate coordinated transmission, or an UL trigger frame can be used to indicate a coordinated UL transmission.

Abstract: Embodiments of the present invention provide systems and methods for synchronous independent channel access in a wireless network. The synchronous independent channel access can be performed by a wireless station having multiple transceivers for simultaneous communication over multiple wireless bands. A wireless station can connect wirelessly to a wireless access point to access a first primary wireless band during a transmission opportunity, and can use early access on a second primary wireless band without receiving a transmission opportunity. The transmission and reception of data frames over the different primary channels are synchronized to prevent or mitigate inter-channel interference. According to some embodiments, the channels are synchronized using back-off procedures and/or padding to align the ending time of transmitted and received data frames, for example.

Abstract: Embodiments of the present invention provide a method and apparatus for hybrid ARQ acknowledgement and retransmission requests for decoding failed MPDUs of an A-MPDU received by an STA. The source address and receiver address of a failed MPDU can be verified according to a MAC header CRC that can be included in an A-Control frame, for example. For verifying the source address and the receiver address in MAC header, according to some embodiments, the MAC header CRC is jointly calculated over the first two octets of the MPDU delimiter of an A-MPDU subframe. Moreover, a Hybrid ARQ frame is defined to include Block Ack Bitmap subfield representing the received status of a plurality of MPDUs according to starting sequence control number, for example.

Abstract: Embodiments of the present invention provide a method and apparatus for coordinated multi-AP channel access in a wireless network. A wireless AP that obtains a transmission opportunity (TXOP) (a “coordinator AP”) can grant one or more STAs or APs under control of the coordinator AP the use of some of the bandwidth granted by the TXOP. The STAs or APs that are granted the use of the bandwidth are referred to as “coordinated APs.” Thereafter, a coordinator AP or a coordinated AP can create a new basic service set (BSS) of devices for coordinating data transmissions. For example, the coordinated AP may serve as a relay, where the coordinated AP services devices in a new BSS by sending and receiving data with a coordinator AP in a different BSS.

Abstract: Signaling and feedback schemes of channel variation information from WLAN receiver are proposed. WLAN receiver performs channel tracking and obtains channel variation information. The signaling and feedback of channel variation information can help WLAN transmitter to decide when to apply travelling pilots or mid-amble in the transmission. Furthermore, the channel variation information can assist WLAN transmitter for scheduling the next transmission properly and thereby enhancing the system performance of WLAN.

Abstract: Mechanisms of CCA status reporting and NAV distribution for coordinated transmissions in a multi-AP WLAN. A coordinator AP may broadcast a RTS frame to a set of coordinated APs, which allow the coordinated APs with a CCA clear status to set a protected period in a CST frame to silence the associated non-AP STAs. The coordinator AP also polls the coordinated APs to have them individually report their CCA statuses as well as additional information used for transmission coordination. In some embodiments, a status report from a coordinated AP may integrate the protected period setting and the CCA clean status indication, and therefore the coordinator AP just needs to poll for such a report without using RTS/CTS exchange. A coordinated AP may set a protected period to end at the complete transmission of a coordination frame. The coordination frame may specify the remaining TXOP duration information.

Abstract: Embodiments of the present invention provide a method and apparatus for enhanced data retransmission based on log-likelihood ratio (LLR) combining in WLAN. According to some embodiments, packets can be retransmitted using a modified transmission scheme. Packets that are received with an error are stored, and a subsequent packet is received that includes data that can be used to correct the error. For example, each packet can be encoded for both error detection and correction, and the retransmission mechanism can be adapted to the error rate. The retransmission scheme is improved by utilizing an LLR combining scheme, transmit diversity, and modified ACK methods.

Abstract: Modulation schemes that use dual sub-carrier to reliably transmit physical layer related signaling information and/or data in high efficiency wireless local area network (HE WLAN) are proposed. The proposed schemes can be implemented with low complexity and provide better performance than existing modulation schemes used in WLAN that are based on IEEE 802.11/a/b/g/n/ac standards. The proposed schemes enhance the reliability of transmissions, especially under narrow band interferences. In accordance with a novel aspect, dual subcarrier modulation (DCM) is introduced in HE WLAN. DCM can introduce frequency diversity into OFDM systems by transmitting the same information on two subcarriers separated in frequency. A DCM indication scheme is used such that both encoding and decoding of DCM is really simple.

Abstract: Methods and apparatus are provided for structured resource allocation signaling. In one novel aspect, an 8-bit RU allocation filed is allocated in the HE-SIG-B common field for each 20 MHz. The structured resource signaling supports more than four MU-MIMO users. In one embodiment, the STA decodes the 8-bit RU allocation signal following a structured resource unit (RU) allocation rule, and determines the RU. In one embodiment, the STA decodes the first two bits of the 8-bit RU allocation signal to determine a first category of the RU allocation. The categories of the RU allocation includes a large RU size category indicating larger than or equal to 20 MHz RUs exist, a two 106-tone category indicating two 106-tone RUs exist, and a no-large-RU category indicating only smaller-than-242-tone RUs exist. The STA further decodes based on the category. A lookup table (LUT) for RU allocation is built and decoded based on a structured signaling rule.

Abstract: A joint sounding mechanism used in a multi-AP system to gain channel information for joint data transmission. Multiple sounding APs can transmit a joint sounding packet that includes training symbols for the antennas of all the sounding APs with regard to the transmission channel. The antennas of the multiple sounding APs may be treated as a virtual antenna array with global antenna indexes. The joint sounding packet may include a plurality of training fields, each field corresponding to a respective antenna in the virtual antenna array. Alternatively, the joint sounding packet has subcarrier-interleaved training fields, where each sounding AP transmits training symbols on an allocated set of non-pilot subcarriers. Channel status information (CSI) can be generated by the STAs in response to the joint sounding packet and supplied to the APs. Accordingly, the APs can perform antenna beamforming and transmit a data packet jointly on the transmission channel.

Abstract: A method of enhanced beamforming procedure to achieve spatial reuse and thereby improving cell edge performance and area throughput is proposed. The enhanced beamforming method increases the likelihood of channel access under dense deployment condition, reduces interference to OBSS, reduces collision during reception, and increases the likelihood of spatial reuse in dense deployment scenario thus leading to higher network throughput.

Abstract: System and method of OFDMA transmission in which mid-ambles are configured on a per-user basis for channel variation adaptation. The multiple channels used in an OFDMA transmission may use different mid-amble settings based on their respective channel characteristics. Particularly, some channels may have mid-ambles and some may have not, and mid-amble update intervals may vary across the channels. For a trigger-based (TB) uplink (UL) OFDMA transmission, an AP may signal the per-user mid-amble information in the user information fields of the trigger frame. For a downlink (DL) OFDMA transmission, an AP may signal the per-user mid-amble information in the HE SIG-B fields.

Abstract: A method of combined direction finding (DF) and fine timing measurement (FTM) positioning in a wireless location area network (WLAN) is proposed. A multiple antenna IEEE 802.11 transmitting device (AP) can transmit signal preamble containing multiple Long Training Field (LTF) symbols in a radio frame from multiple antennas, which allows a receiving device (STA) to resolve multiple DF sounding signals transmitted from the multiple antennas and thereby estimating angle of departure (AoD). On the other hand, the AP can estimate angle of arrival (AoA) from radio signals transmitted from the STA. When the radial resolution error of AoD or AoA positioning increases, DF positioning and fine-timing measurement (FTM) ranging can be jointly applied to reduce the radial resolution error and extends the AoD/AoA service area with positing accuracy.

Abstract: A cooperative multi-band wireless station architecture that enables full duplex operations of wireless stations (STAs). Such an STA includes a WIFI transceiver and one or more additional transceivers. The two transceivers (and the associated channels) operate in mutually exclusive WIFI bands or different types of protocols and therefore can transmit and/or receive simultaneously without signal interference to each other. The multiple transceivers can perform independent clear channel assessment (CCA) and then simultaneously perform signal transmission or reception jointly or independently. In a cooperative multi-band operation, one channel may be used as an independent assistant channel and responsible for supplying assistant information relevant to a transmission opportunity (TXOP) for the other channel (primary channel) to take corresponding actions.

Abstract: Systems and methods of transmitting a multi-user (MU) wake-up packet in WLAN including wake-up signals to activate main radios on multiple communication devices via the wake-up radios (WURs). In the multi-user wake-up packet, a frequency channel can be divided into several sub-channels for transmitting multiple wake-up signals in FDMA. Each wake-up signal is modulated in ON/OFF Key modulation. Two adjacent wake-up signals are adequately spaced apart by a certain frequency spacing to reduce adjacent channel interferences. Once a WUR on a receive device receives the packet, it generates a wake-up indication to wake up the main radio for active data communication. The MU wake-up packet may also include a sequence of multiple wake-up signals transmitted using the same sub-channel and cascaded in a time-domain. A reconfiguration window may be inserted between consecutive wake-up signals on the same sub-channel, and between a legacy preamble and the following wakeup signals.

Abstract: Systems and methods of transmitting a multi-user (MU) wake-up packet in FDMA. In the wake-up setup stage, an STA informs the AP that it can resolve an MU wake-up packet transmitted in FDMA. Accordingly, AP allocates a frequency channel to the STA in a WUR setup response frame which indicates a channel offset relative to the primary channel. Moreover, if a WUR channel allocated to an STA is inaccessible or there is on pending wake-up signal for the STA, no wake-up signal is included in the MU wake-up packet while any other accessible allocated channels may still be utilized for transmitting the scheduled wake-up signals. During such a transmission, an inaccessible channel may be punctured; and an accessible channel having no pending wake-up signal may be used to carry an invalid wake-up signal or a legacy preamble followed with no wake-up signal.

Abstract: Systems and methods of WLAN communication including efficient spatial reuse mechanisms for relay transmissions between a repeater network and non-AP STAs in OFDMA. The non-AP STAs are grouped based on their connectivity with the individual repeaters and the radio coverage regions of the repeaters. Each group is either a non-overlapping group with the constituent non-AP STAs located in a non-overlapping coverage region of a particular repeater, or an overlapping group with the constituent non-AP STAs located in an overlapping coverage region of two or more repeaters. Based on the grouping, certain RUs (or subchannels) are reused for multiple groups without causing inter-group interference, thereby expanding the bandwidths used in the relay operations. RU allocation based on grouping can be used in combination with transmit power adjustment to achieve efficient spatial reuse in OFDMA.

Abstract: Systems and methods of transmitting a PPDU to or from a single user station (STA) in an OFDMA transmission by using multiple RUs. An access point (AP) allocates multiple RUs to an STA for an OFDMA transmission and correspondingly specifies the STA ID repeatedly in the user specific field of a SIG-B field in a downlink PPDU, or in the user information fields of a trigger frame. Alternatively, multiple AIDs of the STA can be specified in the user specific field or the user information fields instead of repeating the same STA ID. An indication may be inserted in the SIG-A field to indicate that the enhanced RU allocation scheme is used for the OFDMA transmission.

Abstract: Systems and methods of transmitting a PPDU to or from a single user station (STA) in an MIMO transmission by using unequal MCSs. An access point (AP) allocates a plurality of spatial streams to the STA and assigned them into groups for the MIMO transmission. Multiple unequal MCSs are assigned to the different spatial stream groups. Correspondingly the STA ID is repeatedly specified in the user block fields of a SIG-B field of a downlink PPDU, or in the user information fields of a trigger frame. Alternatively, multiple AIDs of the STA can be specified in the user block fields or the user information fields instead of repeating the same STA ID. An indication may be inserted in the SIG-A field to indicate that the grouped-based unequal MCSs scheme is used for the MIMO transmission.

Abstract: A method for identifying source BSS in WLAN is proposed. A high efficiency (HE) access point (AP) sends a packet containing a basic service set (BSS) color to a HE station. The HE AP also sends a packet containing an assigned association identification (AID) to a very high throughput (VHT) station. The assigned AID comprises at least part of the BSS color information. The VHT station therefore sends a packet containing the at least part of the BSS color information such that any AP or station that receives the packet can determine the BSS the VHT station is in.