Constraining pulse positions in CELP vocoding
First Claim
1. A method of vocoding an input signal comprising the steps of:
- filtering the input signal resulting in a filtered signal having a first signal pulse and a second signal pulse;
encoding the first signal pulse by association of the first signal pulse with a first pulse position within a first track of a data structure;
assigning the second signal pulse to a second pulse position within a second track of the data structure; and
verifying that the first pulse position and the second pulse position are not a constrain combination.
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Accused Products
Abstract
An apparatus and method for vocoding an input signal comprising a linear predictive filter for generating a filtered signal with a first signal pulse and a second signal pulse in response to receiving the input signal and a processor having a lookup table with a plurality of track positions and a set of rules for constraining the first signal pulse to a first track position in the first plurality of track positions and constraining the second signal pulse to a second track position in the second plurality of pulse positions in accordance with the set of rules. Additionally, the apparatus has a transmitter which transmits the plurality of excitation parameters in a transmission signal in response to receiving the plurality of excitation parameters from the processor.
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Citations
15 Claims
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1. A method of vocoding an input signal comprising the steps of:
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filtering the input signal resulting in a filtered signal having a first signal pulse and a second signal pulse;
encoding the first signal pulse by association of the first signal pulse with a first pulse position within a first track of a data structure;
assigning the second signal pulse to a second pulse position within a second track of the data structure; and
verifying that the first pulse position and the second pulse position are not a constrain combination. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus for vocoding an input signal comprising:
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a linear predictive filter for generating a filtered signal with a first signal pulse and a second signal pulse in response to receiving the input signal;
a processor having a lookup table with a plurality of track positions and a set of rules for constraining the first signal pulse to a first track position in the first plurality of track positions and constraining the second signal pulse to a second track position in the second plurality of pulse positions in accordance with the set of rules; and
a transmitter which transmits the plurality of excitation parameters in a transmission signal in response to receiving the plurality of excitation parameters from the processor. - View Dependent Claims (9, 10, 11, 12, 13)
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14. An article of manufacture comprising:
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a computer usable medium having computer readable program code means embodied therein for vocoding of a signal, the computer readable program code means in said article of manufacture having;
means having a first computer readable program code for filtering of the signal resulting in an residual signal, means having a second computer readable program code for long term predictive filtering of the residual signal resulting in at least a first signal pulse and a second signal pulse, means having a third computer readable program code for identifying a first codebook index associated with the first signal pulse from a codebook, and means having a fourth computer readable program code for identifying a second codebook index associated with the second signal pulse from a codebook such that the second codebook index is constrained by the first codebook index. - View Dependent Claims (15)
assigning the second code book index if the distance is greater than a predetermined distance.
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Specification