Qualcomm Incorporated

RaviKiran Gopalan

Le Nguyen Luong

Koorosh Akhavan

Danlu Zhang

Faramarz Sabouri

James Young Hurt

Mahbod Mofidi

Eunmo Kang

Yu-Han Yang

Markos Troulis

Seyed Mohammad Ehsan Hosseini

Systems and methods are disclosed that may detect a likely presence of a narrow band signal in the presence of wide-band interference without powering up a wireless receiver. A wireless device may receive a wireless signal, measure a first energy level in a first frequency band associated with an expected frequency band of the narrow band wireless signal, measure a second energy level in a second frequency band that is offset from and non-overlapping with the first frequency band, and determine whether a difference between the first energy level and the second energy level exceeds a threshold. A wireless receiver of the wireless device may be powered up based at least in part on the difference between the first energy level and the second energy level exceeding the threshold.

Detecting narrow band signals in wide-band interference

A method for wireless communication is described. The method includes receiving a signal that is pattern-mapped and Gaussian frequency-shift keying (GFSK) modulated. The method also includes performing a joint demapping and demodulation of the received signal based on a stored accumulated phase. The method may further include updating the stored accumulated phase based on the joint demapping and demodulation.

Systems and methods for joint demodulation and demapping

Multiple input multiple output (MIMO) communication systems and methods for chip to chip and intrachip communication are disclosed. In one aspect, MIMO techniques that have been applied to wireless communication systems are applied to interchip and intrachip communication systems. In particular, a transfer function is applied at the transmitter, and a reverse transfer function is applied at the receiver. The transfer function dynamically changes based on channel conditions to cancel or otherwise mitigate electromagnetic interference (EMI) and crosstalk conditions. In an exemplary aspect, a sum of power levels across the channels may have a maximum. To abide by such power level constraint, the transfer function may be optimized to reduce interference while remaining within the power level constraint.

Multiple input multiple output (MIMO) communication systems and methods for chip to chip and intrachip communication

Aspects disclosed in the detailed description include simplified multiple input multiple output (MIMO) communication schemes for interchip and intrachip communications. In exemplary aspects, MIMO techniques are applied to interchip and intrachip communication systems. In particular, a programmable control function is provided at an electrical signal source and supports a default MIMO communication scheme on a MIMO channel comprising possible communication paths among a plurality of transmitting and receiving endpoints. In addition, the programmable control function can opportunistically employ a simplified MIMO communication scheme when the MIMO channel is determined to be a tri-diagonal MIMO channel. The simplified MIMO communication scheme uses an Inverse Fast Fourier Transformation (IFFT) with reduced computational complexity. By employing the simplified MIMO communication scheme, interchip or intrachip communication may be supported with reduced implementation complexity, lower power consumption, and improved robustness.

Simplified multiple input multiple output (MIMO) communication schemes for interchip and intrachip communications

A method includes demodulating a load modulated signal at an initiator device based at least partially on a phase adjusted comparison value corresponding to the load modulated signal.

System and method to demodulate a load modulated signal

A method of joint demodulating and demapping of a digital signal includes receiving a first sequence of the digital signal. The digital signal has a pattern in which a norm of an ideal transmitted sequence of symbols for zero is equal to a norm of an ideal transmitted sequence of symbols for one. The method also includes defining a portion of the first sequence as a third sequence, determining, for each element of a set of the third sequence, one of a real part of a value or an imaginary part of the value of the element, calculating a value for a combination of the determined one of the real part of the value or the imaginary part of the value for the each element of the set, and setting a bit equal to one in response to the value for the combination being less than zero.

Joint demodulating and demapping of digital signal

A method for improving communication sensitivity by a wireless communication device is described. The method includes obtaining a string of bits. The method also includes mapping each bit in the string of bits to a pre-allocated bit pattern to create a series of concatenated pre-allocated bit patterns. The method further includes generating a modulated signal based on the series. The method additionally includes transmitting the modulated signal.

Systems and methods for improving communication sensitivity

Systems, methods, and devices for wireless communication are included herein. An aspect of the subject matter described in the disclosure provides a device configured to detect a transmission. The device includes a receiver configured to receive an inductive communication signal having a center frequency. The device further includes an analog-to-digital converter configured to sample the signal at a rate higher than twice the center frequency. The device further includes one or more processors configured to digitally downconvert the signal. The processors are further configured to compare an energy of the downconverted signal to a detection threshold. The device further includes a transmitter configured to selectively transmit a communication based on the comparison.

Systems and methods for collision avoidance in near-field communications

Aspects disclosed herein relate to improving acquisition for NFC load modulation. In one example, a communications device is equipped to monitor at least a complex component of load modulation of a carrier signal, detect, using a NFC technology type specific peak detection scheme, a peak associated with at least the complex component, and determine a presence of a packet beginning pattern based on the detected peak. In an aspect, the packet beginning pattern may be associated with a reception of a packet from a target NFC device.

Methods and apparatus for improving acquisition for NFC load modulation

Systems, methods, and devices for determining an acquisition threshold boundary value and applying that boundary value to identify which incoming signals are directed to a device, based on matching the device syncword with the syncword for the incoming signal. For some implementations using ANT protocol, syncwords composed of the last four bits of the preamble and first 14 bits of the network address identify each device. Incoming syncwords are correlated with the device's syncword, and the correlation compared to threshold boundary value which is based on the characteristics of the individual syncword, including syncword bit stream inter-symbol interference.

ANT syncword specific acquisition thresholding

In a wireless near field communication (NFC) system, a target, such as a smart card, can communicate with an initiator, such as a card reader, by load modulating a radio frequency (RF) signal generated by the initiator. When two or more targets load modulate the RF signal generated, 'collisions' can occur with the load modulation. Apparatus and methods detect the presence or absence of collisions in a lower layer or physical layer and report the presence of detected collisions to an upper layer for further handling.

Systems and methods for detecting data collisions for a near field communication system

In a particular embodiment, a method includes receiving a first portion of a sync field of a packet at a receiver. The sync field includes the first portion and a second portion. The packet includes the sync field and a payload field. The method includes detecting a sync word associated with the packet. The sync word is detected based on the first portion of the sync field and prior to receiving the second portion of the sync field. The method initiates a demodulation stage of the receiver prior to receiving an initial bit of the payload field. Initiating the demodulation stage prior to receipt of the initial bit of the payload field enables a demodulator to perform initial demodulation activity prior to demodulation of the payload field. Demodulation continues if, after the second portion is received, the entire received sync field matches the detected sync word.

Demodulating a data packet based on a detected sync word

A method for determining an effective frequency offset by circuitry is described. The method includes determining a first frequency offset average over a first half of a syncword. The method also includes determining a second frequency offset average over the entire syncword. The method further includes determining a third frequency offset average over a second half of the syncword. The method additionally includes determining an effective frequency offset at an end of the syncword based on the first frequency offset average, the second frequency offset average and the third frequency offset average.

Systems and methods for performing frequency offset estimation

A method for detecting an access code in a receiver that does not require an explicit DC-offset interference correction block, comprising:

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San Diego, CA, United States of America

RaviKiran Gopalan