公开(公告)号：US20210405174A1

公开(公告)日：2021-12-30

申请号：US16917852

申请日：2020-06-30

Applicant: Apple Inc.

Inventor： Michael KERNER ,  John Zhonghua WU ,  Michael DELISHANSKY ,  Zohar AGON ,  Shachar SHAYOVITZ ,  Michael NEY ,  Shay I. FREUNDLICH

IPC: G01S13/28 ,  G01S13/48 ,  G06F3/0354

Abstract: Accuracy for detecting and tracking one or more objects of interest can be improved using radar-based tracking systems. In some examples, multiple radars implemented in a device can be used to transmit signals to, and receive signals from, the one or more objects of interest. To disambiguate an object of interest from undesired objects such as the hand of a user, the object of interest can include a transponder that applies a delay element to a signal received from a radar, and thereafter transmits a delayed return signal back to the radar. The delay produced by the delay element can separate the return signal from undesired reflections and enable disambiguation of those signals. Clear identification of the desired return signal can lead to more accurate object distance determinations, more accurate triangulation, and improved position detection and tracking accuracy.

公开(公告)号：US20180091348A1

公开(公告)日：2018-03-29

申请号：US15645215

申请日：2017-07-10

Applicant: Apple Inc.

Inventor： Zohar AGON

IPC: H04L27/26 ,  H04L5/00

CPC classification number: H04L27/2623 ,  H04L5/0062 ,  H04L27/2647

Abstract: Embodiments include a method, computer program product, and system for utilizing a system for peak cancellation for a received Orthogonal Frequency Division Multiplexing (OFDM) symbol to reduce the peak-to-average power ratio (PAPR). The system detects M sets of clipping noise samples of the symbol where each set includes one of the M highest clipping noise peaks of the symbol, determines cancellation pulses that correspond to the highest clipping noise peaks of the M sets in the time domain, and subtracts the cancellation pulses from the corresponding highest clipping noise peak samples to reduce the PAPR. The cancellation pulses are determined at least in part from the center-of-mass of each set of the clipping noise samples, the phase of some samples of each set, and the in-band energy limitation associated with the OFDM symbol.

公开(公告)号：US20180083820A1

公开(公告)日：2018-03-22

申请号：US15645187

申请日：2017-07-10

Applicant: Apple Inc.

Inventor： Zohar AGON

IPC: H04L27/26 ,  H04L12/26

CPC classification number: H04L27/2623 ,  H04L43/0847

Abstract: Embodiments include a system, method, and computer program product that receives an Orthogonal Frequency Division Multiplexing (OFDM) symbol, and utilizes a weighted gradient-based adaptive peak cancellation convergence algorithm to create a peak cancellation signal to reduce a peak-to-average power ratio (PAPR) as well as induced error rates of the OFDM symbol. Iterations of the weighted gradient-based adaptive peak cancellation convergence algorithm produce a peak cancellation signal that converges to a desired peak cancellation signal that satisfies a targeted PAPR. Some embodiments utilize a priori knowledge of a power spectral density of clipping noise and pre-defined transmission constraints in the frequency domain to create a peak cancellation signal with specific and desired spectral density properties. For example, some peak reduction tones (PRTs) may be scaled to take advantage of available power resources associated with the pre-defined transmission constraints, where the scaling is specific to each PRT.