Apple Inc.

Broadcom Corporation

National Semiconductor Corporation

Navid Lashkarian

Arya Behzad

Ali Parsa

Ali Afsahi

Karim Nassiri-Toussi

Ling Su

Colin Fraser

Konrad W Kratochwil

Ehsan Adabi

Utku Seckin

Dengwei Fu

Saeed Chehrazi

Albert Chia-Wen Jerng

Marcellus D Forbes

The representative embodiments discussed in the present disclosure relate to techniques in which the transmission and reception of phase array antennas may be measured to more accurately and more efficiently estimate incidence angles of the associated RF signals. More specifically, in some embodiments, RF signals may be transmitted and received by various subsets of antennas in a pair of phased antenna arrays, and the resulting signals may adaptively filtered and fed back to perform iterations until incidence angles may be accurately determined.

Estimation of incidence angles in phased antenna arrays

Systems and method provided herein relate to reducing distortion of signals introduced by components on a phase path of a radio frequency system polar architecture. To reduce phase path distortion, a pre-distortion is introduced prior to a distortion caused by the components on the phase path. The pre-distortion in conjunction with the component distortion results in a transmission signal that forms its expected shape.

Radio frequency systems and methods for polar phase distortion calibration

Systems and method for improving operation of a radio frequency system are provided. One embodiment provides a radio frequency system that includes an amplifier device with a first data path and a second data path. Additionally, the radio frequency system includes a controller that instructs the radio frequency system to transmit a calibration signal, which includes a first portion that excites the first data path and a second portion that excites the second data path; determines time skew between the first and second data paths based at least in part on phase shift between a first sample of a feedback signal and the first portion, phase shift between a second sample of the feedback signal and the second portion, or both; and instructs the radio frequency system to adjust delay applied on the first data path, the second data path, or both based at least on the time skew.

Radio frequency time skew calibration systems and methods

Communication processing paths include distortions, such as DC offset in the baseband analog path, local oscillator feed-through distortion, and nonlinearity of gm's and power amplifiers which are calibrated for, separately or in combination. The cascaded DC offset and nonlinear distortions are modeled separately or in combination using even-and-odd order polynomials. A loopback path from the output of one or more distortion causing devices passes through a measurement and calculation module. The calculation module calculates predistortion polynomial's coefficients which will be stored in a look-up table to be used by a baseband predistorter to calibrate the path. The look-up table is stored locally or remotely.

Calibration of communication processing path

A signal-to-noise estimator is provided for estimating the signal-to-noise ratio in wireless fading channels. The estimator can be applied to likelihood ratio estimation of turbo decoders in third generation wide-band code division multiple access (WCDMA) systems. Time-multiplexed samples of pilot symbols from a wireless receiver are supplied to the estimator to obtain individual estimates of signal power and/or noise power. The estimator uses a de-correlating filter in which the coefficients are known functions (such as eigen-vectors) of the auto-correlation matrix for a wireless channel. The decorrelating filter is used by the estimator to map an observation vector into a set of statistically independent samples. The energy of each vector component is computed individually and combined to produce an aggregate sum for the vector. The aggregate sum can be subtracted from the pilot tone power in order to produce an estimate of noise power.

Signal-to-noise ratio (SNR) estimator in wireless fading channels

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Pleasanton, CA, United States of America

Navid Lashkarian