Realtek Semiconductor Inc.

Wei-Hung He

Chun-Ming Cho

Chin-Tai Chen

Kuang-Yu Yen

Shieh-Hsing Kuo

Hou-Wei Lin

An audio processing method includes: converting a time-domain audio signal into a frequency-domain audio signal; determining a noise reduction gain according to the frequency-domain audio signal; and selecting at least one set of time-domain filter coefficients from a plurality sets of time-domain filter coefficients according to the noise reduction gain; configuring a time-domain filter according to the at least one selected set of time-domain filter coefficients, and filtering the time-domain audio signal with the time-domain filter.

Audio processing method for performing audio pass-through and related apparatus

The present disclosure discloses an audio playback apparatus having noise-canceling mechanism that includes a sound receiving circuit, a storage circuit, a filter control circuit, a filter circuit and an audio playback circuit. The sound receiving circuit receives received audio signal including noise. The storage circuit stores filter parameters. The filter control circuit includes a noise estimation circuit, a noise distribution determination circuit and a parameter generation circuit. The noise estimation circuit receives the received audio signal and calculates a stationary noise power spectrum density of the noise such that the noise distribution determination circuit determines a noise spectrum distribution accordingly. The parameter generation circuit analyses the noise spectrum distribution and retrieves a group of selected filter parameters accordingly. The filter circuit filters the received sound signal according to the group of selected filter parameters to generate an anti-noise audio signal. The audio playback circuit playbacks an actual audio signal and the anti-noise audio signal simultaneously.

Audio playback apparatus and method having noise-canceling mechanism

The present disclosure discloses a sound receiving that includes an air conduction sound receiving circuit, a bone conduction sound receiving circuit, an adaptive filter, a crossover frequency control circuit and a synthesis circuit. The air conduction sound receiving circuit generates an air conduction sound signal. The bone conduction sound receiving circuit generates a bone conduction sound signal. The adaptive filter performs calculation according to a minimum of an error function in real time to generate a transferring filter function to filter the bone conduction sound signal to generate a transferred bone conduction sound signal. The crossover frequency control circuit determines a crossover frequency according to a maximum energy frequency point of the transferring filter function on a frequency domain. The synthesis circuit synthesizes the air conduction sound signal higher than the crossover frequency and the bone conduction sound signal lower than the crossover frequency to generate a synthesized sound signal.

Sound receiving apparatus and method

The present disclosure discloses an audio playback apparatus having a noise-canceling mechanism that includes an audio-receiving circuit, an adjusting parameter generation circuit, a frequency-warping filter circuit and an audio playback circuit. The audio-receiving circuit receives an audio signal. The adjusting parameter generation circuit generates adjusting parameters according to at least the audio signal. The frequency-warping filter circuit includes first order all pass filter units to filter the audio signal in series to generate a plurality of filtered results, multiplication units to respectively multiply each of the filtered results by one of adjusting parameters to generated adjusted filtered results and an adder circuit to add the filtered results to generate a noise-canceling signal. The audio playback circuit playbacks the audio signal and the noise-canceling signal at the same time.

Audio playback apparatus and method having a noise-canceling mechanism

An active noise cancellation (ANC) circuit includes: an audio generating circuit; an audio input unit for transmitting an audio to be broadcast or a sound testing signal as a first time domain signal; an audio receiver for receiving a background sound as a second time domain signal, wherein the background sound corresponds to the audio to be broadcasted or the sound testing signal; and a channel estimation unit, configured to receive the first time domain signal and the second time domain signal, perform time-frequency conversion upon the first time domain signal and the second time domain signal to obtain a first frequency domain signal and a second frequency domain signal respectively, and generate a frequency response according to the first frequency domain signal and the second frequency domain signal. The frequency response is for adjusting an active noise cancelling coefficient of the ANC circuit to improve a noise cancellation effect.

Audio adjustment method and associated audio adjustment circuit for active noise cancellation

The present invention discloses a direction-finding chip, a direction-finding method and a beacon. The direction-finding chip is applied to a beacon of a direction-finding system. The beacon includes multiple antennas and an inertial measurement unit (IMU). A mobile device can calculate angle information according to supplement provided by the beacon. The direction-finding chip includes a computation circuit and a radio frequency circuit. The computation circuit generates coordinate conversion information or a correction amount of the coordinate conversion information according to an acceleration and a magnetic field vector generated by the IMU. The coordinate conversion information or the correction amount can be used to compensate the angle information. The radio frequency circuit is coupled to the computation circuit and configured to transmit the supplement and the coordinate conversion information or the correction amount.

Direction-finding chip, direction-finding method and beacon

The present invention provides an audio adjustment method and associated audio adjustment device for active noise cancellation. The audio adjustment method includes: broadcasting a single tone having a frequency f; generating M sets of filtering coefficients regarding the frequency f, wherein each set of filtering coefficients within the M sets of filtering coefficients includes a combination of an amplitude and a phase, and the M sets of filtering coefficients are different from one another; determining an mset of filtering coefficients from the M sets of filtering coefficients to minimize energy corresponding to the frequency f; and adjusting the single tone with the mset of filtering coefficients to obtain an adjusted single tone corresponding to the frequency f.

Audio adjustment method and associated audio adjustment device for active noise cancellation

An audio playback device having a noise-cancelling mechanism is provided that includes an external sound-receiving circuit that receives external noise, a fixed-coefficient filtering circuit, an operation circuit, an audio playback circuit, an internal sound-receiving circuit and an adjusting circuit. The fixed-coefficient filtering circuit generates an inverted signal including a main and an auxiliary inverted components having the same amplitude and phases orthogonal to each other according to the external noise. The operation circuit multiplies the inverted signal by adjusting parameters to generate an adjusted inverted signal. The audio playback circuit receives and playbacks an audio signal and the adjusted inverted signal to generate a playback result. The internal sound-receiving circuit receives the playback result to generate a received sound signal. The adjusting circuit generates the adjusting parameters according to an error signal between the received sound signal and the audio signal and the inverted signal.

Audio playback device and method having noise-cancelling mechanism

A headset includes a first sound receiving circuit, a second sound receiving circuit, an adaptive circuit, a first synthesis circuit, and a second synthesis circuit. The adaptive circuit is configured to: obtain a first direction of arrival and a second direction of arrival according to a first sound signal and a second sound signal; obtain a first conversion function and a second conversion function according to the first direction of arrival and the second direction of arrival; obtain a first feed forward audio signal according to the first conversion function and the first sound signal; and obtain a second feed forward audio signal according to the second conversion function and the second sound signal.

Headset

An apparatus for detecting a null symbol of an input signal includes: a first circuit for processing the input signal to obtain a first output signal, the first output signal being used to track the influence of a channel phenomenon; a second circuit for processing the input signal to obtain a second output signal, the second output signal being used to track the null symbol in the input signal; and a determining circuit coupled to the first circuit and the second circuit and determining the null symbol of the input signal according to the first output signal and the second output signal. A method for detecting a null symbol of an input signal is also disclosed.

Apparatus and method for detecting null symbols

A frequency offset acquisition method includes: receiving a specific sequence signal transmitted through a channel; shifting a frequency of the specific sequence signal at a plurality of different frequencies in frequency domain to thereby generate a plurality of shifted sequence signals respectively; and determining an estimated frequency offset value between a transmitter and a receiver according to the shifted sequence signals.

Frequency offset acquisition method and apparatus thereof

An audiovisual processing system comprises a signal receiving circuit and a host device. The signal receiving circuit comprises a tuner and a demodulator. The tuner generates a tuned signal based on a radio frequency signal. The demodulator generates a digital signal based on the tuned signal, generates a frequency down-converted signal based on the digital signal, generates an audio processing signal based on the frequency down-converted signal in an audio processing mode, generates a demodulated video signal based on the frequency down-converted signal in a video processing mode, generates an output signal based on the audio processing signal in the audio processing mode, and generates the output signal based on the demodulated video signal in the video processing mode. The host device receives the output signal, and generates a demodulated audio signal based on the output signal in the audio processing mode.

Integrated digital broadcasting receiver system

A pseudo noise code (PN code) tracking circuit includes a first correlator, a storage device, a second correlator and a detector. The first correlator is utilized for performing correlation on a first PN code in a first signal frame with a local PN code to generate a first set of correlation values, and for performing correlation on a second PN code in a second signal frame with the local PN code to generate a second set of correlation values. The storage device is coupled to the first correlator for storing the first and second sets of correlation values. The second correlator is coupled to the storage device for performing correlation on the first set of correlation values with the second set of correlation values to generate a shift value. The detector is coupled to the second correlator for generating a frame number according to the shift value.

Pseudo noise code tracking circuit and pseudo noise code tracking method

A single carrier/multi carrier community receiver includes: a first discrete Fourier transform unit, for generating a frequency-domain signal by executing a first discrete Fourier transform on a received signal received via the single carrier/multi carrier; a first frequency-domain equalizer, for generating a first equalized frequency-domain signal by executing a first equalizing process on the frequency-domain signal; an inverse discrete Fourier transform unit, coupled to the first frequency-domain equalizer, for generating a first equalized time-domain signal executing an inverse discrete Fourier transform according to the first equalized frequency-domain signal; a slicer, coupled to the inverse discrete Fourier transform unit, for generating a sliced time-domain signal by executing a slicing process according to the first equalized time-domain signal; and a compensating circuit, for compensating the first equalized frequency-domain signal or the first equalized time-domain signal at least according to the sliced time-domain signal.

Single carrier/multi carrier community receiver

A single-carrier/multi-carrier community receiver includes a discrete Fourier transform unit, a frequency-domain equalizer, an inverse discrete Fourier transform unit and an inter-symbol interference (ISI) cancellation unit. The discrete Fourier transform unit is utilized for executing a discrete Fourier transform upon a received signal to generate a frequency-domain signal. The frequency-domain equalizer is utilized for executing an equalization operation upon the frequency-domain signal to generate a frequency-domain equalized signal. The inverse discrete Fourier transform unit is utilized for executing an inverse discrete Fourier transform upon the frequency-domain equalized signal to generate a time-domain equalized signal. The ISI cancellation unit is utilized for executing an ISI cancellation operation upon the time-domain equalized signal to generate an ISI-cancelled signal.

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Taipei Hsien, Taiwan

Wei-Hung He