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: A new lower density parity check (LDPC) tone mapper is proposed when DCM is applied for a given resource unit (RU) when LDPC is used as the channel control coding. For HE PPDU transmission with DCM, LDPC encoded streams are first modulated by a DCM constellation mapper. The modulated symbols of the lower half of the frequency segment and the modulated symbols of the upper half of the frequency segment are modulated using the same LDPC encoded bits using DCM mapping. The modulated symbols of the lower half of the frequency segment are mapped to lower half of the data subcarriers using DCM LDPC tone mapper. The modulated symbols of the upper half of the frequency segment are mapped to upper half of the data subcarriers using the same DCM LDPC tone mapper. Maximum frequency diversity for DCM can be achieved.

Abstract: A method of transmitting and receiving a HE PPDU and perform channel estimation enhancement is proposed. The HE PPDU comprises legacy preamble, HE-STF, HE-LTF, and data. A beam-change indication indicates if the pre-multiplied beamforming Q-matrix is changed from legacy preamble to H-SFT, HE-LTF, and data portion. A value of 1 indicates that Q matrix is changed. A value of 0 indicates that Q matrix is unchanged and receiver should be safe to combine L-LTF and HE-LTF. The beam-change indication can be used to significantly enhance channel estimation at receiver. When there is no beam-change, receiver does not change operation during HE-STF and HE-LTF such that the channel estimations can rely on the combination of L-LTFs, L-SIG, RL-SIG, HE-SIGAs and HE-LTF.

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 method of spatial reuse with opportunistic transmit power control (TPC) and clear channel assessment (CCA) is proposed. In the opportunistic TPC and CCA, a spatial reuse station (SR-STA) gains enough knowledge in certain situation for more aggressive spatial reuse such that its transmit power may be adjusted to meet the spatial reuse conditions based on the received OBSS PPDU and the corresponding spatial reuse parameter (SRP). Both Type 1 SRP and Type 2 SRP are defined. In one example, the Type 1 or Type 2 SRP is a 5-bit parameter carried in the HE-SIG-A field of the OBSS PPDU, which can be a trigger frame, a response frame, a request-to-send (RTS)/clear-to-send (CTS) frame, and a data frame.

Abstract: Methods and apparatus are provided for HE-SIG-B common field formats and indications. In one novel aspect, a fixed format is used for HE-SIG-B common field indicating resource allocations (RA). In one embodiment, look-up tables (LUT) are configured for the resource allocation and indicated in the HE-SIG-B common field. In one embodiment, one or more RA LUTs are used based on the operation bandwidth. The RA LUTs are placed in an order of channel indexes from lower channel to upper channel signaled in each corresponding RA LUT. In another novel aspect, MU-MIMO is used for operation bandwidth of 160 MHz and a compression indicator is set in the HE-SIG-A field indicating a saving of all RA LUTS in the HE-SIG-B common field. In yet another novel aspect, a one-bit middle-tone indicator is included in the HE-SIG-B common field indicating whether the one or more middle 26 tone is used.

Abstract: A method of direction finding (DF) positioning in a wireless location area network (WLAN) is proposed. A multiple antenna IEEE 802.11 transmitting device can transmit signal preamble containing multiple Long Training Field (LTF) symbols in a radio frame from multiple antennas simultaneously, which allows a receiving device to resolve multiple DF sounding signals transmitted from the multiple antennas. As a result, angle of departure (AoD) of the transmitting device can be estimated by using the multiple resolved DF sounding signals from each antenna for DF positioning purpose.

Abstract: A method of sub-channel feedback in OFDMA systems is provided. A wireless receiving device (STA) receives a radio signal from a transmitting device (AP) over a wide channel in an OFDMA system. The radio signal is transmitted over multiple sub-channels of the wide channel. The STA estimates channel quality information based on the received radio signal for each sub-channel. The STA then sends feedback information to the transmitting device. The feedback information comprises the estimated channel quality information for a selected subset of sub-channels from the wide channel based on a predefined rule. In one embodiment, the feedback information is embedded within an ACK/BA frame or is carried in a frame immediately subsequent to the ACK/BA frame.

Abstract: A method of supporting incompatible channelization in a wireless communications system is provided. A coordinating device determines a first set of physical parameters of a first wireless channel. The first set of physical parameters includes a channel bandwidth, a central frequency, a transmit power limit, and a modulation and coding scheme. The coordinating device establishes communication with a first set of communications devices over the first wireless channel. The coordinating device then broadcasts a channel-adjustment message and determines a protection period. The channel-adjustment message comprises a set of instructions on how to adjust to a second set of physical parameters of a second wireless channel. A second set of communications devices adjust physical parameters based on the channel-adjustment message. Finally, the coordinating device communicates with the second set of communications devices over the second wireless channel during the protection period.

Abstract: A unified channel contention scheme is proposed such that spatial reuse can be enabled by a wireless station (STA) when a basic service set (BSS) color of a received signal cannot be resolved. If the detected frame is an intra-BSS frame, then the STA should not contend the channel for the PPDU duration. If the detected frame is an inter-BSS frame, then the STA uses OBSS Packet Detection (OBSS-PD) level as the CCA level for channel contention. Furthermore, when BSS color cannot be resolved, channel contention schemes for WiFi signal and non-WiFi signal are differentiated. If the received signal is detected as WiFi signal, then the STA uses WiFi-SIG Detection (WD) level as the CCA level for channel contention. If the received signal is detected as non-WiFi signal, then the STA uses Non-WiFi-SIG Detection (NWD) level as the CCA level for channel contention.

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 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.

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: A method of sounding and feedback with channel quality information and reduced overhead is provided. A receiving station receives a sounding signal transmitted from an access point over multiple sub-channels of a wide channel in a wireless network. The receiving station detects channel quality based on the received sounding signal for each sub-channel. The receiving station then performs channel estimation based on the received sounding signal and thereby determining feedback information. Finally, the receiving station transmits a feedback message to the access point, the feedback message contains NULL feedback information, reduced feedback information, or channel integrity/quality indicators based on the channel quality information for each sub-channel. Based on the feedback message, the access point may repeat the sounding process, narrow the transmission bandwidth, or select only stations who have indicated uncorrupted channel sounding for MU-MMO transmission.

Abstract: The present invention provides a method and an electronic apparatus for transmitting a packet with changeable spreading factor. The method comprises: utilizing a spreading circuit to select a spreading factor from a plurality of spreading factors according to a transmitting condition to adjust a spreading for the packet; and transmitting the packet. The electronic apparatus comprises: a spreading circuit and a transmitting circuit. The spreading circuit is utilized for selecting a spreading factor from a plurality of spreading factors according to a transmitting condition to adjust the spreading for the packet. The transmitting circuit is coupled to the spreading circuit, and utilized for transmitting the packet.

Abstract: The present invention provides a method and an electronic apparatus for automatically detecting bandwidth and the packet type of a packet, so as to solve the problem mentioned above. The method comprises: detecting a plurality of symbols in the preamble of the packet; generating a sign pattern according to the symbols; and determining the bandwidth and the packet type of the packet according to the detected sign pattern. The electronic apparatus comprises: a symbol detecting circuit, a sign pattern generating circuit, and a determining circuit. The symbol detecting circuit is utilized for detecting a plurality of symbols in the preamble of the packet. The sign pattern generating circuit is utilized for generating a sign pattern according to the symbols. The determining circuit is utilized for determining the bandwidth and the packet type of the packet according to the detected sign pattern.

Abstract: A novel feedback schemes are introduced to assistant link adaptation for re-transmissions and to improve the network throughput and efficiency. When reception failure is a type B failure, then a failure report (FR) frame is feedback from the destination STA to the source STA. In the failure report frame, link adaptation information and information on failure causes are included.

Abstract: A method of channel estimation enhancement is provided. In a wireless communications system, a transmitting device transmits a long preamble frame comprising a first training field, a signal field, and a second training field. The signal field has a beam-change indicator bit indicates whether there is beam change between the first training field and the second training field. A receiving device receives the long preamble frame, performs a first channel estimation based on the first training field, and performs a second channel estimation based on the second training field. If the beam-change indicator bit indicates negative beam change, then the receiving device performs channel estimation enhancement by combining the first channel estimation and the second channel estimation. As a result, channel estimation performance is improved.

Abstract: A method of improved allocation of uplink resources in an OFDMA network is proposed. A wireless communications station (an AP) reserves both dedicated resource and contention resource for uplink OFDMA operation for a list of communications devices (STAs). The AP can switch between random access operation and non-random access operation without the need for any special protection mechanisms. In the event of an increase in uplink OFDMA frame collisions the AP can switch from random operation to non-random operation to reduce the number of collisions. In the event of a decrease in uplink OFDMA frame collisions the AP can switch from non-random operation to random operation to reduce required AP processing. The AP can also dynamically control a STA access probability to reduce the number of collisions by reducing the number of uplink OFDMA frames each STA transmits.

Abstract: A method to improve the area throughput of dense wireless local area networks (WLAN) by channel access control is proposed. The method allows an access point to obtain information of a plurality of stations within the wireless network. The access point classifies the plurality of stations into at least one group of stations and assigns a group identification (ID) according to the obtained information. The group ID and channel access control parameters are sent to the stations that are classified into the certain group. The stations in each of the group use the received channel access control parameters to communicate with the access point.