 Cryptographic key, or other secret material, recovery |
| According to the present invention there is provided a method permitting secure storage and secure ... |
|
| Music speech filter |
| This invention electronically and automatically determines whether an audio signal is music or ... |
|
| Compatible four channel FM system |
| A four channel audio system is provided which is fully compatible with standard FM stereo and mono ... |
|
| Digital signal processor for adding harmonic content to digital audio signal |
| It is an object of the present invention is to provide added harmonic content to an audio signal in ... |
|
| Method and device for preventing unauthorized access to a computer system |
| I claim: 1. A method for preventing access to a computer system, comprising a processing unit or ... |
|
| Sound field forming circuit and sound field forming apparatus |
| It is an object of the invention to provide a sound field forming circuit which solves the problem, ... |
|
| Minimal inductance electrodynamic transducer |
| Accordingly, it is an object of this invention to reduce the non-linearity and distortion produced ... |
|
| Encryption apparatus |
| The present invention proposes an encryption system which avoids the need of having to optimise the ... |
|
| Data communications system using public key cryptography in a web environment |
| To solve this problem, in accordance with the present invention there is now provided a ... |
|
| Speech encoding apparatus and related decoding apparatus |
| It is an object of this invention to provide an improved speech encoding apparatus. It is another ... |
|
|
Signal processing system and method for digitally mixing a plurality of analog input signals
| Details |
Inventors: Fraisse, Christian;
Assignee: SGS-Thomson Microelectronics S.A. (Gentilly, FR)
Primary Examiner: Chin; Stephen
Assistant Examiner: Maddox; Michael W.
Attorney, Agent or Firm: Wolf, Greenfield & Sacks, P.C., Morris; James H., Galanthay; Theodore E.
A signal processing system receives and mixes a plurality of analog input signals having a maximum frequency. Each analog input signal is connected to an input of a modulator producing a high frequency oversampled digital signal. Each high frequency oversampled signal is connected to an input of a first decimation filter which produces an intermediate frequency oversampled multiple bit signal. Each of the intermediate frequency oversampled signals is connected to a respective input of a first digital mixer which produces a single mixed multiple bit output signal. The single mixed multiple bit output signal is connected to a second decimation filter which produces a final digital output signal, at a frequency suitable for representing the mixed analog input signals. |
|
DETAILED DESCRIPTION In one illustrative embodiment of the invention, a signal processing system is provided, receiving a plurality of analog input signals having a maximum frequency and effecting mixing of the analog input signals.
Each analog input signal is connected to an input of a modulator, producing a high frequency oversampled digital signal.
Each high frequency oversampled signal is connected to an input of a first decimation filter which produces an intermediate frequency oversampled multiple bit signal.
Each of the intermediate frequency oversampled signals is connected to a respective input of a first digital mixer, which produces a single mixed multiple bit output signal.
Furthermore, the single mixed multiple bit output signal is connected to a second decimation filter which produces a final digital output signal, at a frequency suitable for representing the mixed analog input signals.
In an embodiment of the invention, the signal processing system comprises a gain control circuit acting on each intermediate frequency oversampled signal between the first decimation filter and the first digital mixer.
In an embodiment of the invention, each first decimation filter comprises a convolution circuit acting on the respective high frequency oversampled signal, and receiving a sequence of impulse response coefficients common to all convolution circuits.
In an embodiment of the invention, the sequence of impulse response coefficients is stored in a common memory.
In an embodiment of the invention, the convolution circuit produces the intermediate frequency oversampled signal by summing coefficients corresponding to 1's of the high frequency oversampled signal, and subtracting coefficients corresponding to 0's of the high frequency oversampled signal.
In an embodiment of the invention, the signal processing system further comprises an interpolation filter connected to receive the final digital output signal and producing an interpolated signal; a second digital mixer receiving the interpolated signal, and at least one other digital signal, and producing an interpolated mixed digital signal; and a digital-to-analog converter receiving the interpolated mixed digital signal
|
| Related patents |
|
|
Single-chip audio system power reduction circuitry and methods
A single chip audio system includes a bus interface, digital to analog converters, analog mixer, and analog spatial enhancement circuitry. Digital to analog converters ...
|
|
|
Mixing, coding and decoding devices and methods
It is therefore a primary object of the present invention to provide a mixing device and a mixing method which are capable of mixing bitstream data without having to ...
|
|
|
Robot pre-positioning in a wafer processing system
Synchronized, Conflict Resolving Schedulers An aspect of the present invention comprises a method for maximizing throughput and quality in a manufacturing system by ...
|
|
|
Digital interface circuit
The subject invention overcomes the disadvantages of the prior art including those mentioned above in that it comprises a digital interface circuit/protocol converter ...
|
|
|
Encryption apparatus, cryptographic communication system, key recovery system, and storage medium
OF THE INVENTION A preferred embodiment of the present invention will now be described. In the following description, "key piece" implies shared key data; "key ...
|
|
|
Broadcast receiver
OF THE PREFERRED EMBODIMENT Using the antenna 1, a sterophonic broadcast signal is received, the two audio signals of which for the right-hand and left-hand sound ...
|
|
|
Electronic reverberation device
I claim: 1. An electronic reverberation device comprising an input amplifier having an input and an output, an output amplifier having an input and an output, a delay ...
|
|
|
Apparatus and method for reestablishing previously established settings on the controls of an audio mixer
It is an object of the present invention to provide an apparatus and method for reestablishing previously established settings on the controls of an audio mixer that is ...
|
|
|
Digit-serial recursive filters
OF THE INVENTION The concepts underlying the present invention are best illustrated by an example. In particular, consideration is given to the addition of two 16-bit ...
|
|
|
Auscultation augmentation device
The main object of the present invention is to provide a compact, battery-powered device to be used with a conventional stethoscope that will materially improve the ...
|
|
|
Audio Signal Processing 
