Signal processing apparatus and method for sigma-delta modulated signals including gain adjustment
AssigneeSony Corporation
InventorGen Ichimura
Life of this patent
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Abstract
A signal processing apparatus in which the effective dynamic range information for maintaining linearity of an output signal is appended to a transmitted 1-bit digital signal as ancillary data. When the 1-bit signal is converted into a multi-bit digital signal, the gain of the 1-bit signal is adjusted on the basis of the effective dynamic range information.
Claims4
A signal processing apparatus for processing a digital data string formed by a synchronization signal, subdata and sigma-delta modulated main data having a sampling frequency equal to m.times.fs (Hz), where m is a positive integer larger than 1 (m>1) and formed as a 1-bit digital signal, comprising:
- data separating means for separating the main data and the subdata from the transmitted digital data string;
- data conversion means for converting the 1-bit main data having the sampling frequency equal to m.times.fs (Hz), where m>1, separated by the data separating means, into a quantized k-bit digital signal having a sampling frequency equal to n.times.fs (Hz), where n is a positive integer smaller than m (m>n), and k is a positive integer larger than 1 (k>1);
- wherein
- said data conversion means includes gain adjustment means for maintaining linearity of a converted main data output;
- said gain adjustment means being controlled on a basis of effective dynamic information specifying a range of linearity of the main data output contained in the subdata separated by the data separating means.
A signal processing method for converting a digital data string formed by a synchronization signal, subdata and sigma-delta modulated main data formed as a 1-bit digital signal and having a sampling frequency equal to m.times.fs (Hz), where m is a positive integer larger than 1 (m>1), into a quantized k-bit digital signal, having a sampling frequency equal to n.times.fs (Hz), where n is a positive integer smaller than m (m>n), and k is a positive integer larger than 1 (k>1), comprising the steps of:
- separating the main data and the subdata from the transmitted digital data string;
- converting the 1-bit main data with the sampling frequency equal to m.times.fs (Hz), where m>1, separated by the step of separating, into a quantized k bit digital signal having a sampling frequency equal to n.times.fs (Hz), where n is a positive integer smaller than m (m>n) and k is a positive integer larger than 1 (k>1);
- and
- adjusting a gain of the main data output from said step of converting for maintaining linearity of a converted main data output on a basis of effective dynamic information specifying a range of linearity of the main data output contained in the subdata for maintaining linearity of the converted main data output.
Dependencies are inferred from the claim text.