Qualcomm Incorporated

Qualcomm Atheros Inc.

Google Inc.

Kai Shi

Ning Zhang

Paul J Husted

James Simon Cho

Sandip HomChaudhuri

Zhanfeng Jia

David Kuochieh Su

Tao-Fei Samuel Ng

Ahmed Ibrahim ElArabawy

Youhan Kim

Kenneth Marvin Gainey

Qinfang Sun

Shahram Abdollahi-Alibeik

Srenik Suresh Mehta

MeeLan Lee

Qifan Chen

Ian David O'Donnell

Subramania Sharma Thandaveswaran

Soraya Kasnavi

Junyi Li

Xinzhou Wu

Alireza Raissinia

William John McFarland

Xiaoxin Zhang

Ying Wang

Jubin Jose

Chin-Hung Chen

Tevfik Yucek

Shu Du

John S Thomson

Praveen Dua

Richard Chang

Susinder Rajan Gulasekaran

Sang-Min Lee

Zhen Xie

Meriam Khufu Ragheb Rezk

Richard Mosko

Sandip Homchaudhuri

Srinivas Jasti

Joe I Jamp

Bruce Busby

Felix Bitterli

Chao Cheng

Ahmed H Hassan

John Thomson

Sankara S Venkateswaran

Tuofu Lu

Richard Melvin Mosko, Jr

Ahmed Ibrahim Elarabawy

Meelan Lee

Tao-Fei S Ng

This document describes methods, devices, systems, and means for a switching scheme for opting in and out of multi-user orthogonal frequency-division multiple access (MU-OFDMA). In one aspect, an electronic device enters the MU-OFDMA mode to communicate via a wireless network over a shared-channel bandwidth. During the MU-OFDMA mode, the electronic device determines that an uplink-queue size is greater than a first threshold size. Responsive to the determining, the electronic device opts out of the MU-OFDMA mode and enters a single-user mode to contend for a transmit channel for transmitting uplink data.

Switching scheme for opting in and out of multi-user orthogonal frequency-division multiple access

This disclosure provides systems, methods and apparatuses for selecting a guard interval for transmission of orthogonal frequency-division multiplexing (OFDM) symbols on an uplink (UL) channel and on a downlink (DL) channel. In some implementations, a transmitting device and a receiving device can estimate channel delay spread (CDS) information for each other's transmit channels, exchange the estimated CDS information with each other, and select a guard interval based on the estimated CDS information exchanged with each other. The transmitting device can transmit a number of OFDM symbols separated by the selected guard interval to the receiving device on the UL channel, and the receiving device can transmit a number of OFDM symbols separated by the selected guard interval to the transmitting device on the DL channel.

FTM protocol enhancements for channel delay spread

In a multiple-input, multiple-output (MIMO) system, a wireless node's receive chain demodulation function is enhanced to include phase tracking. VHT Long Training Fields (LTFs) embedded in a frame preamble are used for phase tracking. Single stream pilot tones are added during transmission of VHT-LTFs. A receiver estimates the channel using the pilot tones in a first set of LTFs. A second set of LTFs are used to estimate the phase of the pilot tones using the estimated channel. The phase estimation is continuously applied to other received data tones throughout the VHT-LTFs of data symbols. Phase errors due to PLL mismatches and phase noise are reduced at reception, leading to better signal to noise ratio for different levels of drift and frequency offset. Further, MIMO channel estimation is more accurate, improving the overall wireless network when the accurate MIMO channel estimation data participates in calibration and handshake between wireless nodes.

Single stream phase tracking during channel estimation in a very high throughput wireless MIMO communication system

In MIMO a wireless node's receive chain demodulation function is enhanced to include phase tracking using very high-throughput long training fields (VHT-LTFs) embedded in a frame preamble. Single stream pilot tones are added during transmission of VHT-LTFs. A receiver estimates the channel using the pilot tones in a first set of VHT-LTFs, and estimates the phase of the pilot tones using a second set of VHT-LTFs. The phase estimation receiver estimates the channel using the pilot tones in a first set of VHT-LTFs. The phase estimation is continuously applied to other received data tones throughout the VHT-LTFs of data symbols. Phase errors due to PLL mismatches and phase noise are reduced at reception, leading to better signal to noise ratio for different levels of drift and frequency offset.

Methods, systems, and devices are described for power conservation in a wireless communications system. In embodiments, power conservation may be achieved by adaptively controlling power modes of a wireless communication device, using a modulation and coding scheme (MCS) value as a factor for guidance. According to one aspect, the device may be in a reception mode. While in a first power mode, the device may receive control information for incoming data that is being transmitted via a transmission frame. The control information may be located in a first portion of the frame with the data following in a second portion of the frame. The control information may include or otherwise indicate an MCS value corresponding to the MCS applied to the incoming data. Based on the MCS value, the device may be adaptively switched to a second power mode for receiving the incoming data.

Adaptive control of RF low power modes in a multi-rate wireless system using MCS value

Methods, systems, and devices are described for power conservation in a wireless communications system. In embodiments, power conservation may be achieved by adaptively controlling power modes of a wireless communication device, and implementing lower power modes with various modes of the device. According to one aspect, the mode of the device may be a beacon monitoring mode or a delivery traffic indication message (DTIM) mode. In such a mode, the device may receive a portion of a beacon in a first power mode. The device may transition to a second, different (e.g., higher) power mode using information contained in the received portion of the beacon as guidance.

Adaptive control of RF low power modes in a multi-rate wireless system using device mode

Methods, systems, devices, and apparatuses are described for wireless communications in which first type of traffic may be transmitted from a gateway access point (AP) directly to a station. Beacon signals transmitted to the station are transmitted as part of the first type of traffic. A second type of traffic may be transmitted from the gateway AP to the station via at least one relay AP. The first type of traffic may include low-throughput traffic and may be transmitted over a long-range radio link (e.g., 2 GHz band link or sub-1 GHz band link). The second type of traffic may include high-throughput traffic and may be transmitted over at least one short-range radio link (e.g., 5 GHz band link). The gateway AP may receive low-throughput traffic directly from the station and high-throughput traffic from the station via the at least one relay AP.

Multi-band management of wireless relaying networks

A system and method for transmitting LDPC parameters is provided. In the method, an initial number of OFDM symbols (Nsym_init) is determined for a packet that is based on the number of information bits to be delivered in the packet. An STBC value is also determined. A number of extra symbols (Nsym_ext) value is generated based on the Nsym_init value, wherein a Nsym value is based on said Nsym_init value and said Nsym_ext value. An Nldpc_ext value is determined based on the STBC value and the Nsym_ext value for purposes of determining LDPC parameters associated with the packet.

System and method for transmitting a low density parity check signal

A first combination of frequency bands is selected for transmitting a first data packet, and a second, different combination of frequency bands is selected for transmitting a second data packet. A data stream is divided into a first set of data and a second set of data. The first set of data is allocated to the first combination of frequency bands, and the second set of data is allocated to the second combination of frequency bands.

Selecting frequency bands for transmitting data packets

A method and apparatus are disclosed for searching for a radar signal within signals received by a wireless device. The wireless device may receive signals within a first frequency segment and a second frequency segment, which is adjacent to the first frequency segment. The wireless device may determine Fast Fourier Transform (FFT) bins associated with the first frequency segment and the second frequency segment. The wireless device may combine the FFT bins associated with the first frequency segment and the second frequency segment and may search for the radar signal within the combined FFT bins.

Radar detection for adjacent segments in wireless communications

Methods, systems, and devices are described for detecting dedicated short range communications (DSRC) transmissions to determine whether to use at least a portion of the DSRC spectrum. In one embodiment, a multi-mode device may be operated outside of the DSRC spectrum using a first clock rate, and may then be switched to a second clock rate while operating outside of the DSRC spectrum to detect DSRC transmissions using the DSRC spectrum.

DSRC listen mode for Wi-Fi using DSRC spectrum

Improved methods of decoding data symbols of a high throughput (HT) data field in a mixed mode packet are provided. In one embodiment, first and second data symbols of the HT data field can be decoded using timing information derived from a legacy header of the mixed mode packet. In another embodiment, the first data symbol of the HT data field can be decoded using timing information derived from a legacy header of the mixed mode packet, whereas the second data symbol of the HT data field can be decoded using approximately half of the tones of the HT long training field in the mixed mode packet. Subsequent data symbols of the HT data field can be decoded using all tones of the HT long training field in the received mixed mode packet.

Fine timing for high throughput packets

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San Jose, CA, United States of America

Kai Shi