Qualcomm Incorporated

Cisco Technology, Inc.

Airgo Networks, Inc.

James M Gardner

Vincent Knowles Jones, Iv

Geert Arnout Awater

D J Richard Van Nee

Didier Johannes Richard Van Nee

Gregory C Steele

Vincent K Jones

Derek Gerlach

Jonathan S Leary

Alireza Raissinia

Sandip HomChaudhuri

Richard Van Nee

Vincent K Jones Iv

Burcin Baytekin

Jayanand Asok Kumar

Maarten Menzo Wentink

Xiaoxin Zhang

Albert Van Zelst

Michael A Pollack

Tevfik Yucek

Soumen Chakraborty

Shahram Abdollahi-Alibeik

Michael Kohlmann

Klaas Wortel

Tienyow Liu

Niranjan Anand Talwalkar

Lalitkumar Nathawad

Rainer Gaethke

Sumeet Kumar

Kapil Rai

Arvind Keerti

Patrick Kelliher

Paul Brandon Butler

Suresh Chandrasekaran

Chiao Cheng Huang

Felix Bitterli

Prasanna K Basaralu Subramanya

Shwetank Kishorkumar Mistry

Vikram Kandukuri

Manyuan Shen

Mani Krishnan Venkatachari

Ming-Tuo Chin

Kyungwan Nam

Geert Arnaut Awater

Geert Amout Awater

Ramaprasad Samudrala

Christopher Pisz

Mani Bharathi Pandian

Vincent K Iv Jones

Geert Arnoult Awater

Techniques are provided for radio frequency (RF) sensing using a single wireless device. An example method for determining a distance to an object with radio frequency sensing includes transmitting a radio frequency signal with a transmit channel on a wireless device, receiving a leakage signal with a receive channel on the wireless device at a first time, such that the leakage signal is based on the radio frequency signal, receiving a reflected signal with the receive channel on the wireless device at a second time, such that the reflected signal is based on the radio frequency signal reflecting from the object, and determining the distance to the object based at least in part on a difference between the first time and the second time.

Radio frequency sensing using a single device based on concurrent transmit and receive

This disclosure provides methods, devices and systems for reducing power consumption when a station (STA) is operating in a listen mode. In some aspects, to reduce power consumption in the listen mode, the STA may alternate between monitoring a wireless channel for packets and not monitoring the wireless channel. When the STA is monitoring the wireless channel for packets in the listen mode, the STA may configure packet detection components to a power-on state. When the STA is not monitoring the wireless channel in the listen mode, the STA may configure packet detection components to a power-off state. During the power-on state of the listen mode, the STA may detect a preamble of a packet that was transmitted over the wireless channel. In response to detecting the preamble of the packet, the STA may switch from the listen mode to a receive mode to process the packet.

Reducing listen mode power consumption of a wireless local area network (WLAN) device

This disclosure provides systems, methods and apparatuses for wireless communications. In some implementations, a first wireless communication device associated with a basic service set (BSS) receives a plurality of packets transmitted during a measurement window by a second wireless communication device associated with the BSS. The first wireless communication device determines a received signal strength indicator (RSSI) value of the plurality of received packets, determines a level of overlapping basic service set (OBSS) interference on the wireless medium during the measurement window, and adjusts one or more of a packet detect (PD) threshold, an OBSS PD threshold, or an energy detect (ED) threshold based on the determined RSSI value and the level of OBSS interference.

Adaptive detection threshold for contention-based channel access

Methods, systems, and devices are described for wireless communication at a wireless communication device. A wireless communication device may receive a data frame and use it to estimate a residual channel length (RCL). The device may then modify a finite impulse response (FIR) filter based on the estimated RCL. For example, the device may add additional taps to the FIR filter. The device may continue to adjust the FIR filter until the RCL is at or near zero. In some cases, the wireless communication device may send an indication to the transmitting device to adjust an FIR filter based on the estimated RCL. In some cases, the length of a guard interval may also be adjusted based on the estimated RCL.

Delay spread estimation and utilization

This disclosure provides systems, methods, and apparatus, including computer programs encoded on computer storage media, for contemporaneously estimating transmitter in-phase and quadrature (I/Q) imbalances, receiver I/Q imbalances, and transmit carrier leakage in a wireless transceiver. In some implementations, first, second, and third frequency-domain multi-tone (FDMT) signals transmitted through a calibration path of the wireless transceiver are captured to generate frequency domain representations of the first, second, and third FDMT signals. The frequency domain representations of the first, second, and third FDMT signals may be used to contemporaneously estimate the transmitter I/Q imbalances, receiver I/Q imbalances, and the transmit carrier leakage, which in turn may be used to determine transmitter and receiver I/Q imbalance correction filter coefficients and a transmit carrier leakage correction factor.

TX/RX imbalance and carrier leakage calibration

A system and method for calibrating digital pre-distortion in a wireless device. A pre-distortion circuit may output a first training signal while a power amplifier of the wireless device is on, to generate a first feedback signal. The first feedback signal may be fed back to the pre-distortion circuit via a receive path of the wireless device. The pre-distortion circuit may output a second training signal while the power amplifier is off, to generate a second feedback signal. The second feedback signal may be fed back to the pre-distortion circuit via the receive path. The pre-distortion circuit may then determine one or more pre-distortion coefficients based on the first and second feedback signals.

Closed loop digital pre-distortion

A method and apparatus are disclosed for a wireless communication device capable of scanning for radar signals while detecting and/or receiving a wireless communication signal. The wireless communication device may include a plurality of local oscillator synthesizers to allow distinct frequency bands to be used for wireless communication signals and radar detection. In some embodiments, the wireless communication device may include a radar detection physical layer (PHY) circuit to detect the presence of radar signals within a received RF signal. The radar detection PHY may have limited functionality suitable primarily for radar signal analysis and not suitable for processing (decoding) communication signals.

Agile radar detection for wireless communications

Embodiments of the present disclosure provide techniques for reducing power consumption by wireless devices through transmission output power control.

Output power control for advanced WLAN and bluetooth-amp systems

A method for providing uplink spatial division multiple access (SDMA) transmission opportunities (TXOP) is described. A demarcation indication may be sent to one or more subscriber stations. An SDMA contention window may be started. An allocation indication may be received. Requested uplink SDMA TXOP resources may be allocated according to the allocation indication.

Systems and methods for providing a separate contention window allowing allocations for pending uplink SDMA transmission opportunities

Systems, methods and apparatus a provided for calibrating actual output power of a transmit power sensor for closed loop power control using a quality metric such as error vector magnitude (EVM) to improve power detection accuracy. In aspects, a method for correlating an output of a transmit power sensor with actual output power of a wireless transmitter includes deriving a characteristic correlation between an actual output power of a set of transmit amplifiers and an output power and of a set of corresponding power detection circuits over a range of transmit power levels in a corresponding set of wireless devices; storing the characteristic correlation in a wireless device that is not part of the set from which the characteristic correlation was derived; and sensing an output of a transmit power sensor of the device while the transmitter of the device transmits according to one or more gain settings.

Methods and apparatus for power amplifier calibration

A modified preamble is used by extended devices that operate at higher rates, MIMO or other extensions relative to strict 802.11a-compliant devices. The extended devices might use multiple antenna techniques (MIMO), where multiple data streams are multiplexed spatially and/or multi-channel techniques, where an extended transmitter transmits using more than one 802.11 a channel at a time. Such extensions to IEEE 802.11 a can exist in extended devices. The modified preamble is usable for signaling, to legacy devices as well as extended devices, to indicate capabilities and to cause legacy devices or extended devices to defer to other devices such that the common communication channel is not subject to unnecessary interference. The modified preamble is also usable for obtaining MIMO channel estimates and/or multi-channel estimates. The modified preamble preferably includes properties that facilitate detection of conventional and/or extended modes ('mode detection') and provides some level of coexistence with legacy IEEE 802.11 a devices.

Modified preamble structure for IEEE 802.11A extensions to allow for coexistence and interoperability between 802.11A devices and higher data rate, MIMO or otherwise extended devices

A soft symbol decoder for use in a multiple input multiple output (MIMO) and OFDM (orthogonal frequency division multiplexing) system. The decoder generates soft symbol values for a digital signal that represents a number of source bits. The source bits are transmitted as symbols in corresponding to points in a signaling constellation. Soft metrics are determined by searching for all possible multi-dimensional symbols that could have been transmitted. The method includes transmitting a sample of the multi-dimensional symbol using K transmit antennas. The multi-dimensional symbol is represent-able as a complex, K-dimensional vector x. Each vector component of vector x represents a signal transmitted with one of the K transmit antennas. After transmission through a communication channel, a sample corresponding to the transmitted sample is received. The received sample is represented by a complex, N-dimensional vector y, where N is the number of receive antennas in the MIMO system. After the sample is received, a soft metric L(b) is determined for each bit bencoded by x according to the equation: and xrepresents all possible values for x. In addition, a reduced complexity method is used for providing soft metric values in the MIMO system. This exemplary aspect reduces the complexity of the above computations from 2to 2, where B is the number of bits transmitted per symbol per antenna.

System for soft symbol decoding MIMO log-map detection

Systems and methodologies are described that facilitate calibration techniques for a station in a wireless communication system that can be utilized to provide joint estimates for distortion introduced by in-phase and quadrature (I/Q) imbalance and mixing-product modulated images.

I/Q calibration for walking-IF architectures

A packet detector joint detects 802.11a packets, 802.11b packets and interference that is within a monitored frequency range but is not formatted as 802.11a packets or 802.11b packets. The packet detector can use signals from one or more antennas. Detection of signals is done using differentially detected correlations. In addition to packet detection, the packet detector can identify signal levels, noise levels and locations of narrowband interference. The process of packet detection and identifying other indicators can be done simultaneously and as the signal is being received.

Joint packet detection in a wireless communication system with one or more receivers

A receiver chain is provided for use in wireless data communication including a plurality of receive antennas and a vector Barker decoder or a CCK decoder. The vector Barker decoder operates on the plurality of received signals, preferably processed through a plurality of channel matched filters. The weightings of the plurality of channels can be done using a slicer variance, a PLL variance or another method.

Multi-antenna wireless receiver chains with vector decoding

Growing community of inventors

San Jose, CA, United States of America

James M Gardner