noise shaping


Also found in: Wikipedia.

noise shaping

(communications)
Spectral noise transformation in a quantisation processes. Noise is "colourised" in the time domain an/or frequency domain by adding parts of the previous sample. The SNR bandwidth and SNR time integral stay the same, so some noise decreases, some increases, but overall noise always increases.

An example of noise shaping in the frequency domain is quantisation of samples on a Compact Disc to reduce noise below -98 dB. The are different algorithms with slightly different filters, e.g. Super Bitmapping, 4D Recording.

A time domain example is MPEG-4 AAC TNS, which is a method to enhance quality by temporal forming of the noise in a transform block.
Mentioned in ?
References in periodicals archive ?
1) The noise shaping inherent in this type of converter makes possible the high resolution provided by many models of [SIGMA][DELTA] devices.
Using a multi-path gated ring oscillator at this work has demonstrated first- order noise shaping characters.
And the SC-BTT490 Home cinema system delivers state-of-the-art Panasonic technology that produces impressive cinema-like surround sound based on MASH noise shaping technology with Anti-Jitter Digital Amplifier to reduce distortion.
Here is a small sampling of paper topics to give a sense of the technical level: rate distortion bounds for binary erasure source using sparse graph codes, subsampling-adaptive directional wavelet transform for image coding, fixed-lag smoothing for low-delay predictive coding with noise shaping for Lossy networks, and shape recognition using vector quantization.
Over the past decade, researchers have gone from wiring genetic toggle switches and oscillators in living cells to building living circuits capable of pattern generation, noise shaping, edge detection and event counting.
All ADC circuits must put up with some noise, and oversampling and noise shaping help decrease quantization noise.
What Tangerine Dream played that night was an astonishing, brutal set of white noise shaping.
Wouldn't it be nice to know beforehand what jitter, noise shaping, etc.
The method uses noise shaping to destroy all energy in the spurious signals and to convert the signals to noise, which is shaped like a highpass spectrum so the loop can filter it.
Rounding out the chapter are presentations of digital signal processing, filter designs, digital-to-analogue converters, chip sets, low-bit D/A conversion, noise shaping, and serial transmission format.
The sigma-delta process provides noise shaping, so a low-pass filter can eliminate much of the transient energy that has been shifted to high frequencies.