Silicon Laboratories Inc.

Advanced Micro Devices Corporation

Legerity, Inc.

Yan Zhou

Wentao Li

Terry Lee Dickey

Michael Wu

Guner Arslan

John M Khoury

Hendricus De Ruijter

David S Trager

Antonio Torrini

Jin Li

Vijayakumaran Velayudhan Nair

Michael A Wu

Marius Goldenberg

Safdar M Asghar

Saf M Asghar

Michael James Mills

Rangakrishnan Srinivasan

Russell W Bell

Paul R Teich

Merle L Miller

Qiang Li

Jeffrey Allan Whaley

Jeffrey Jay Anderson

Xun Yang

He Gou

Sherman E Lee

Mustafa H Koroglu

Mohamed M Elsayed

Junsong Li

Eric B Smith

Vitor Pereira

Clayton H Daigle

Younes Djadi

Shouli Yan

Walter Stuart Schopfer

Sergio R Ramirez

Mitchell Reid

Riad S Wahby

Francesco Barale

Jeffrey A Tindle

Sean Anthony Lofthouse

Zhongda Wang

Wenhuan Yu

Ping Xiong

Praveen Vangala

Trenton John Grale

V Vijayakumaran Nair

Albert K Lu

Amey Naik

Yi Shen Yeh

Xushuai Qu

Liguang Pang

John B Youngblood

Jonathan C Grigsby

J A Bolton

A wireless communications device includes a receiver having a phase detector configured to extract frequency offset and provide a corresponding error signal generated based on a baseband version of a received radio frequency signal and an expected transmitted data signal. The receiver has a phase-locked loop configured to generate an error correction signal based on a phase of the error signal and a predicted instantaneous phase of the error signal. The receiver has a correction circuit configured to provide a corrected baseband version of the received radio frequency signal based on the baseband version of the received radio frequency signal and the error correction signal. The receiver may have a re-encoding-based processing circuit configured to provide the expected transmitted data signal based on a preliminarily decoded symbol.

Kalman filter based phase-locked loop with re-encoding based phase detector

A demodulator has a correlator bank with multiple correlators. The correlator bank has multiple configurations, including a signal arrival configuration, a coarse timing configuration, and a despreading configuration. The various configurations are used to correlate function transformations of received symbols to template signals. Each correlator has elements with a number of delay blocks corresponding to a number of chips in a symbol. The output of each delay block is multiplied by a bit of a template signal by negating or not negating the output and the multiplications results are summed. A function transformations block receives phase information to generate the function transformations, which are supplied to the correlators. The function transformations include a transformation with a one chip differential, transformations with multi-chip differentials, an average transformation that includes an average of a one-chip phase difference between two adjacent samples, and a second order phase differentiation used for frequency deviation correlation.

Configurable correlator bank for a non-coherent DSSS demodulator

Techniques for quickly and accurately determining whether a channel is being used for transmission of data using one of a plurality of communications protocols for low power signals using random data of a packet are disclosed. The techniques increase sensitivity and reduce the false alarm rate for a wide range of signal and noise levels. A noise detection technique uses an adaptive window size for fast noise detection that increases the rate of scanning channels during a signal identification period. In a BLE1M detection mode, detection of clusters of zero frequency deviation are used to reduce the false detection rate. Adaptive Zigbee symbol detection improves detection sensitivity beyond −97 dBm. The techniques use a chip-based differential to generate frequency deviation samples for Zigbee detection or data filtering frequency deviation samples generated using sample-based differentials based on an oversampled received signal to improve the signal-to-noise ratio.

Noise detection for multi-channel and multi-protocol communications

An apparatus includes a radio-frequency (RF) receiver for receiving an RF signal using a plurality of antennas. The RF receiver includes a demodulator to provide a switch signal to cause the RF receiver to use an antenna in the plurality of antennas. The RF receiver further includes a carrier frequency offset (CFO) correction circuit that estimates and removes a carrier frequency offset.

Apparatus for receiver with carrier frequency offset correction using frequency information and associated methods

A receiver includes a demodulator having a configurable correlator bank that helps with fast and robust signal detection. The demodulator detects arrival of a first preamble symbol using a first correlator bank configuration. The demodulator makes a course coarse frequency offset estimation after detection of the first preamble signal and the receiver adjusts a frequency used by a mixer based on the coarse frequency offset estimation. The demodulator confirms signal arrival detection with detection of a second preamble symbol. A coarse timing estimation is generated using a second correlator bank configuration using a multi-symbol observation period. A fine frequency offset estimation is made using a third correlation bank configuration. A fine timing estimation is made using a fourth correlation bank configuration. The demodulator then despreads received symbols using a fifth correlator bank configuration.

Non-coherent DSSS demodulator with fast signal arrival detection and improved timing and frequency offset estimation

A wireless communication device has a receiver to listen to a sequence of channels. A controller responds to a preamble being detected on a first channel while the receiver is tuned to the first channel by causing the receiver to stay on the first channel and decode packet(s) associated with the preamble. The controller responds to detection of a first symbol of a first transmission protocol and the preamble not being detected to cause the receiver to stay on the first channel for a predetermined time waiting for a retry. The controller responds to detection of a second symbol of a second transmission protocol and the preamble not being detected to cause the receiver to switch to an advertising channel of the second transmission protocol. If no preambles, noise, or symbols are detected, the receiver switches to listening to a next channel in the sequence after a fixed time.

Concurrent listening

In at least one embodiment, a method for measuring a distance between a first communications device including a first local oscillator and a second communications device including a second local oscillator includes unwrapping N phase values to generate N unwrapped phase values. N is an integer greater than one. Each of the N phase values indicate an instantaneous phase of a received signal. The method includes averaging the N unwrapped phase values to generate an average phase value. The method includes wrapping the average phase value to generate a final phase measurement of the first local oscillator with respect to the second local oscillator.

Phase measurements for high accuracy distance measurements

Signal identification for multi-channel and multi-protocol communications

A phase-locked loop (PLL) that provides a local oscillator signal for a radio. An oscillator of the PLL supplies an oscillator output signal. Control logic receives a request to change the oscillator output signal to a new frequency and responds to the request by setting a first capacitor circuit of the oscillator to a first capacitance that corresponds to a predetermined frequency of the oscillator output signal. The control logic also responds to the request by setting one or more other capacitor circuits of the oscillator according to temperature and according to a frequency difference between the predetermined frequency and the new frequency. After responding to the request by setting the first capacitor circuit and the one or more other capacitor circuits, the PLL locks to the new frequency using a signal from the PLL loop filter to adjust another capacitor circuit in the oscillator.

Fast frequency synthesizer switching

A receiver concurrently demodulates data transmitted with a plurality of protocols. The receiver utilizes multiple and simultaneous protocol detections at preamble and/or packet payload phases. To provide robust detection and achieve fewer false detections, the receiver extends the cross correlation length once a short cross-correlation is valid. The receiver includes a first demodulator path and a second demodulator path with different filter bandwidths. The second demodulator path includes a decimator that reduces data by two. A correlator bank is coupled to the first and second demodulator paths and concurrently detects preamble symbols associated with a plurality of protocols. A first noise detector is coupled to the first demodulator path and a second noise detector is coupled to the second demodulator path. A first symbol identifier circuit is coupled to the first demodulator path and a second symbol identifier circuit coupled to the second demodulator path to provide packet payload symbol detection.

Context switching demodulator and symbol identifier

An apparatus includes a radio-frequency (RF) receiver for receiving an RF signal using a plurality of antennas. The RF receiver includes a demodulator to provide a switch signal to cause the RF receiver to use an antenna in the plurality of antennas. The RF receiver further includes a carrier frequency offset (CFO) correction circuit that uses an estimation of the carrier frequency offset and an estimation of phase differences to remove the carrier frequency offset.

Apparatus for receiver with carrier frequency offset correction using phase and frequency information and associated methods

A method for communicating between a first radio frequency communications device including a first local oscillator and a second radio frequency communications device including a second local oscillator includes generating phase values based on samples of a received signal. Each of the phase values indicates an instantaneous phase of the received signal. The method includes unwrapping the phase values to generate unwrapped phase values. The method includes generating frequency offset estimates based on the unwrapped phase values. The method includes generating an average frequency offset estimate based on the unwrapped phase values. The method includes wrapping the average frequency offset estimate to generate a residual frequency offset estimate. The method includes adjusting the first local oscillator based on the residual frequency offset estimate, thereby reducing a frequency offset between the first local oscillator and the second local oscillator.

Correction of frequency offset between initiator and reflector

A system and method for one-way ranging is disclosed. The system comprises a transmitter, also referred to as tag, transmitting a packet having a first frequency. The receiver, also referred to as the locator, receives the first frequency and measures the phase at a specific point in time. At a predetermined time, the transmitter switches to a second frequency. This is performed while maintaining phase continuity. The receiver also switches to the second frequency at nearly the same time. The receiver then measures the phase of the second frequency at a second point in time. Based on these two phase measurements, the distance between the transmitter and the receiver may be calculated.

One way ranging synchronization and measurement

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Austin, TX, United States of America

Yan Zhou