Qualcomm Incorporated

James Young Hurt

Nikolai Schlegel

Jong Hyeon Park

Je Woo Kim

Serguei A Glazko

Sameer Nanavati

Paul J Husted

Jeffrey Alexander Levin

Roland Reinhard Rick

Le Nguyen Luong

Michael Alexander Howard

Yann Ly-Gagnon

Faramarz Sabouri

Yuanning Yu

RaviKiran Gopalan

Bok Tae Sim

Eunmo Kang

Robert Fuchs

Kuei-Chiang Lai

Daniel Jose Fernandes Barros

Preethi Chandrasekhar

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

Systems and methods are disclosed for compensating I-Q imbalance in a wireless receiver. The receiver may employ a quadrature downconverter configured to receive an RF signal input and output an in-phase component and a quadrature component at an IF, an IF rotation block configured to downconvert the in-phase and quadrature components to baseband and an I-Q correction block configured to compensate for an I-Q imbalance in the received signal, wherein the I-Q correction block is positioned downstream from the IF rotation block in the signal path. Performing the I-Q correction after conversion to baseband may allow the compensation calculations to operate at a reduced digital rate. Similarly, digitally adjusting the gain of the signal prior to I-Q compensation may reduce the number of bits that are manipulated during the compensation process. These features may represent significant efficiencies as compared to I-Q corrections performed at IF.

System and method for I-Q imbalance correction

In a wireless communication system, an initiator, such as a card reader, can communicate with a target, such as a smart card or other device emulating a smart card, by amplitude modulating a radio frequency signal. In a receiver, levels of samples of a digital baseband signal of the amplitude modulated signal can vary. Apparatus and methods associate a received sample with a hard or sliced output state (such as +1, 0, or &#x2212;1) and update a value associated with the hard output state for accurate slicing of the samples. This permits the use of hard symbols in further processing rather than soft samples, which can dramatically reduce the complexity of circuitry.

Adaptive slicer for a discrete level amplitude modulation receiver

A method and apparatus for combining retransmitted hybrid automatic repeat-request (HARQ) messages divided into coding blocks in an orthogonal frequency-division multiplexing (OFDM)/orthogonal frequency-division multiple access (OFDMA) receiver are provided. According to such a coding-block-based HARQ combining scheme, the quality of each coding block may be compared to a threshold to determine whether the decoded bits or the HARQ combined signal should be saved for each coding block for subsequent HARQ iterations. In addition to reducing the required HARQ buffer size while preserving the combining gain, coding-block-based HARQ combining may also provide fast decoding and reduced power consumption when compared to conventional HARQ combining techniques.

Coding block based HARQ combining scheme for OFDMA systems

A method and apparatus for combining retransmitted hybrid automatic repeat-request (HARQ) messages at different stages in an orthogonal frequency-division multiplexing (OFDM)/orthogonal frequency-division multiple access (OFDMA) receiver are provided. The type of HARQ combiner used for a particular channel may depend on a number of selection criteria including the modulation order of the transmission, the number of bits needed for the combined signals, and the headroom in the HARQ buffer. For some embodiments, a combination of different types of HARQ combiners may be designed into a receiver and selected on a per-channel basis. Proper selection of a HARQ combining scheme may reduce the required HARQ buffer size and may provide an increased combining gain when compared to conventional HARQ combining techniques.

Selective HARQ combining scheme for OFDM/OFDMA systems

An access terminal for processing a communication signal includes a receiver. The receiver is configured to determine a bias point for the communication signal based on a quality measurement of the communication signal, the quality measurement having a carrier-to-interference (C/I) estimate associated therewith. The receiver is further configured to determine a C/I cap for the communication signal using the C/I estimate, the C/I cap being configured to cap a signal to interference-plus-noise ratio (SINR) of the communication signal. In addition, the receiver is configured to process the communication signal using the determined bias point and the determined C/I cap. A method is also provided for processing a communication signal.

Method and apparatus for processing a communication signal

Certain embodiments of the present disclosure provide techniques for channel estimation without resorting to the channel second-order statistics. Methods and systems are proposed for improving the performance of an un-constrained least squares channel interpolator by using available side information of the channel, such as signal-to-noise ratio (SNR), Doppler frequency and/or delay spread.

Methods and systems for least squares block channel estimation

A method and apparatus is provided for efficient processing of signal in a communication system. The processing of the signal for transmission may include encoding a block of data at an encoding rate 1/R. The encoding produces R number of data symbols for every data bit in the block of data. A block of RAM () is partitioned into a plurality of blocks of RAM to allow reading simultaneously data symbols from the plurality of blocks of RAM to produce an in-phase and a quad-phase data symbols simultaneously. At least two scramblers (and) are used for simultaneously scrambling the in-phase and quad-phase data symbols. A Walsh covering/summing block () followed by the scramblers provides efficient Walsh covering and summing of signals for a combined transmission from the communication system.

Method and apparatus for efficient Walsh covering and summing of signals in a communication system

An efficient method and apparatus for implementing a back-end channel matched filter in a receiver is disclosed. A typical channel matched filter embodiment includes a peak detector for establishing processing synchronization from a despread signal, a channel estimator producing a channel impulse response (CIR) estimate from the despread signal based on the synchronization by the peak detector and a back-end symbol combiner coherently combining dominant multipath components of the despread signal by weights based on the CIR estimate based on the synchronization by the peak detector to generate a decision variable. In a digital spread spectrum implementation, the despread signal operated on by the channel matched filter has been previously been correlated with a spreading sequence replica.

Efficient back-end channel matched filter (CMF)

Communication system method and apparatus

A method and apparatus for encoding multiple bits in parallel wherein outputs are generated recursively. During each clock cycle, the encoder processes multiple bits and generates outputs consistent with those generated sequentially over multiple clock cycles in a conventional convolutional encoder. In one embodiment, input data is stored in multiple memory storage units, which are then each uniquely addressed to provide data to parallel encoders.

Method and apparatus for coding bits of data in parallel

A method and apparatus is provided for efficient processing of signal in a communication system. The processing of the signal for transmission may include encoding a block of data at an encoding rate 1/R. The encoding produces R number of data symbols for every data bit in the block of data. A block of RAM is partitioned into a plurality of blocks of RAM to allow reading simultaneously data symbols from the plurality of blocks of RAM to produce an in-phase and a quad-phase data symbols simultaneously. At least two scramblers are used for simultaneously scrambling the in-phase and quad-phase data symbols. A Walsh covering/summing block followed by the scramblers provides efficient Walsh covering and summing of signals for a combined transmission from the communication system.

A method and apparatus for efficient encoding of linear block codes uses a lookup table including a set of impulse responses to support faster performance by encoding in parallel. Advantages include a scalability that is lacking in existing schemes.

Method and apparatus for encoding of linear block codes

A method and apparatus is provided for efficient processing of signal in a communication system. The processing of the signal for transmission may include encoding a block of data at an encoding rate 1/R. The encoding produces R number of data symbols for every data bit in the block of data. A block of RAM ( ) is partitioned into a plurality of blocks of RAM to allow reading simultaneously data symbols from the plurality of blocks of RAM to produce an in-phase and a quad-phase data symbols simultaneously. At least two scramblers ( and ) are used for simultaneously scrambling the in-phase and quad-phase data symbols. A Walsh covering/summing block provides efficient Walsh covering and summing of signals for a combined transmission from the communication system.

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San Diego, CA, United States of America

James Young Hurt