High frequency content recovering method and device for over-sampled synthesized wideband signal
DCFirst Claim
1. A decoder for producing a synthesized wideband signal, comprising:
- a) a signal fragmenting device for receiving an encoded version of a wideband signal previously down-sampled during encoding and extracting from said encoded wideband signal version at least pitch codebook parameters, innovative codebook parameters, and linear prediction filter coefficients;
b) a pitch codebook responsive to said pitch codebook parameters for producing a pitch codevector;
c) an innovative codebook responsive to said innovative codebook parameters for producing an innovative codevector;
d) a combiner circuit for combining said pitch codevector and said innovative codevector to thereby produce an excitation signal;
e) a signal synthesis device including a linear prediction filter for filtering said excitation signal in relation to said linear prediction filter coefficients to thereby produce a synthesized wideband signal, and an oversampler responsive to said synthesized wideband signal for producing an over-sampled signal version of the synthesized wideband signal; and
f) a high-frequency content recovering device comprising;
i) a random noise generator for producing a noise sequence having a given spectrum;
ii) a spectral shaping unit for shaping the spectrum of the noise sequence in relation to linear prediction filter coefficients related to said down-sampled wideband signal; and
iii) a signal injection circuit for injecting said spectrally-shaped noise sequence in said over-sampled synthesized signal version to thereby produce said full-spectrum synthesized wideband signal.
6 Assignments
Litigations
3 Petitions
Accused Products
Abstract
In a method and device for recovering the high frequency content of a wideband signal previously down-sampled, and for injecting this high frequency content in an over-sampled synthesized version of the wideband signal to produce a fill-spectrum synthesized wideband signal, a random noise generator produces a noise sequence having a given spectrum. A spectral shaping unit spectrally shapes the noise sequence in relation to linear prediction filter coefficients related to the down-sampled wideband signal. A signal injection circuit finally injects the spectrally-shaped noise sequence in the over-sampled synthesized signal version to thereby produce the full-spectrum synthesized wideband signal.
85 Citations
54 Claims
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1. A decoder for producing a synthesized wideband signal, comprising:
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a) a signal fragmenting device for receiving an encoded version of a wideband signal previously down-sampled during encoding and extracting from said encoded wideband signal version at least pitch codebook parameters, innovative codebook parameters, and linear prediction filter coefficients; b) a pitch codebook responsive to said pitch codebook parameters for producing a pitch codevector; c) an innovative codebook responsive to said innovative codebook parameters for producing an innovative codevector; d) a combiner circuit for combining said pitch codevector and said innovative codevector to thereby produce an excitation signal; e) a signal synthesis device including a linear prediction filter for filtering said excitation signal in relation to said linear prediction filter coefficients to thereby produce a synthesized wideband signal, and an oversampler responsive to said synthesized wideband signal for producing an over-sampled signal version of the synthesized wideband signal; and f) a high-frequency content recovering device comprising; i) a random noise generator for producing a noise sequence having a given spectrum; ii) a spectral shaping unit for shaping the spectrum of the noise sequence in relation to linear prediction filter coefficients related to said down-sampled wideband signal; and iii) a signal injection circuit for injecting said spectrally-shaped noise sequence in said over-sampled synthesized signal version to thereby produce said full-spectrum synthesized wideband signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 53, 54)
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9. A decoder for producing a synthesized wideband signal, comprising:
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a) a signal fragmenting device for receiving an encoded version of a wideband signal previously down-sampled during encoding and extracting from said encoded wideband signal version at least pitch codebook parameters, innovative codebook parameters, and linear prediction filter coefficients; b) a pitch codebook responsive to said pitch codebook parameters for producing a pitch codevector; c) an innovative codebook responsive to said innovative codebook parameters for producing an innovative codevector; d) a combiner circuit for combining said pitch codevector and said innovative codevector to thereby produce an excitation signal; and e) a signal synthesis device including a linear prediction filter for filtering said excitation signal in relation to said linear prediction filter coefficients to thereby produce a synthesized wideband signal, and an oversampler responsive to said synthesized wideband signal for producing an over-sampled signal version of the synthesized wideband signal; the improvement a high-frequency content recovering device comprising; i) a random noise generator for producing a noise sequence having a given spectrum; ii) a spectral shaping unit for shaping the spectrum of the noise sequence in relation to linear prediction filter coefficients related to said down-sampled wideband signal; and iii) a signal injection circuit for injecting said spectrally-shaped noise sequence in said over-sampled synthesized signal version to thereby produce said full-spectrum synthesized wideband signal. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 50)
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17. A cellular communication system for servicing a geographical area divided into a plurality of cells, comprising:
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a) mobile transmitter/receiver units; b) cellular base stations respectively situated in said cells; c) a control terminal for controlling communication between the cellular base stations; d) a bidirectional wireless communication sub-system between each mobile unit situated in one cell and the cellular base station of said one cell, said bidirectional wireless communication subsystem comprising, in both the mobile unit and the cellular base station; i) a transmitter including an encoder for encoding a wideband signal and a transmission circuit for transmitting the encoded wideband signal; and ii) a receiver including a receiving circuit for receiving a transmitted encoded wideband signal and a decoder for decoding the received encoded wideband signal, said decoder comprising; (1) a signal fragmenting device for receiving an encoded version of a wideband signal previously down-sampled during encoding and extracting from said encoded wideband signal version at least pitch codebook parameters, innovative codebook parameters, and linear prediction filter coefficients; (2) a pitch codebook responsive to said pitch codebook parameters for producing a pitch codevector; (3) an innovative codebook responsive to said innovative codebook parameters for producing an innovative codevector; (4) a combiner circuit for combining said pitch codevector and said innovative codevector to thereby produce an excitation signal; (5) a signal synthesis device including a linear prediction filter for filtering said excitation signal in relation to said linear prediction filter coefficients to thereby produce a synthesized wideband signal, and an oversampler responsive to said synthesized wideband signal for producing an over-sampled signal version of the synthesized wideband signal; and (6) a high-frequency content recovering device comprising; a) a random noise generator for producing a noise sequence having a given spectrum; b) a spectral shaping unit for shaping the spectrum of the noise sequence in relation to linear prediction filter coefficients related to said down-sampled wideband signal; and c) a signal injection circuit for injecting said spectrally-shaped noise sequence in said over-sampled synthesized signal version to thereby produce said full-spectrum synthesized wideband signal. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 51)
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25. A mobile transmitter/receiver unit comprising:
a receiver including a receiving circuit for receiving a transmitted encoded wideband signal and a decoder for decoding the received encoded wideband signal, said decoder comprising; i) a signal fragmenting device for receiving an encoded version of a wideband signal previously down-sampled during encoding and extracting from said encoded wideband signal version at least pitch codebook parameters, innovative codebook parameters, and linear prediction filter coefficients; ii) a pitch codebook responsive to said pitch codebook parameters for producing a pitch codevector; iii) an innovative codebook responsive to said innovative codebook parameters for producing an innovative codevector; iv) a combiner circuit for combining said pitch codevector and said innovative codevector to thereby produce an excitation signal; v) a signal synthesis device including a linear prediction filter for filtering said excitation signal in relation to said linear prediction filter coefficients to thereby produce a synthesized wideband signal, and an oversampler responsive to said synthesized wideband signal for producing an over-sampled signal version of the synthesized wideband signal; and vi) a high-frequency content recovering device comprising; (1) a random noise generator for producing a noise sequence having a given spectrum; (2) a spectral shaping unit for shaping the spectrum of the noise sequence in relation to linear prediction filter coefficients related to said down-sampled wideband signal; and (3) a signal injection circuit for injecting said spectrally-shaped noise sequence in said over-sampled synthesized signal version to thereby produce said full-spectrum synthesized wideband signal. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 52)
Specification