Composite signal generation and decoding in digital signal processing automotive audio system
AssigneeFord Motor Company
InventorsJohn E. Whitecar, Gregory R. Hamel, Sylvester P. Porambo
Life of this patent
Estimating the term…
Abstract
A digital signal processing automotive audio system uses an analog audio source providing stereo output signals. One of the stereo signals is mixed to a distinct frequency band and summed with the other stereo signal to form a composite signal which can be digitized in a single analog-to-digital converter. Separate digital stereo signals are recovered using digital signal processing.
Claims5
A digital signal processing automotive audio/ system having an analog audio source, comprising:
- a stereo signal source providing a first analog audio signal and a second analog audio signal;
- mixing means coupled to said stereo signal source for mixing said second audio signal with an analog mixing signal having a predetermined frequency to generate a frequency-shifted audio signal;
- summing means coupled to said stereo signal source and said mixing means for summing said first audio signal and said frequency-shifted audio signal to generate a composite analog signal;
- an analog-to-digital converter coupled to said summing means and receiving said composite analog signal for generating a composite digital signal;
- and
- digital decoding means coupled to said analog-to-digital converter for recovering a first digital audio signal and a second digital audio signal.
A method for converting first and second analog audio signals from a stereo audio source to first and second digital audio signal in an automotive audio system with digital signal processing, comprising the steps of:
- mixing said second analog audio signal with an analog mixing signal having a predetermined frequency to generate a frequency-shifted audio signal;
- summing said first analog audio signal and said frequency-shifted audio signal to generate a composite analog signal;
- sampling said composite analog signal to generate a composite digital signal;
- and
- digitally decoding said composite digital signal to recover said first digital audio signal and said second digital audio signal.
Dependencies are inferred from the claim text.