Subband decoding method and apparatus

Claim 2

In a subband coding system including an encoder having an input signal and a decoder, a method for providing an improved reconstructed signal at the decoder, comprising the following steps: (a) providing a partially reconstructed signal based on information received from the encoder: (b) receiving from the encoder N subband energy values E k , where k varies from 1-N, each E k based on the energy present in a particular spectral subband of the original input signal: (c) providing N noise/waveform fill signals, each having an energy value E' k , where the E' k is provided by the following steps: (c 1 ) computing values A, B which minimize ##EQU3## (c 2 ) computing N values Z k based on E k -(Ak+B), where k varies from 1-N; (c 3 ) identifying the largest Z k (Z k |max); (c 4 ) computing N values E' k based on E k -ξ(Z k |max -Z k ), where k varies from 1-N and ξ is a predetermined constant; (d) combining the noise/waveform fill signals with said partially reconstructed signal.

Claim 3

The method of claim 1 wherein ξ is generally=0.3.

Claim 4

The method of claim 1 wherein N=11.

Claim 5

A subband coding system including an encoder having an input signal and a decoder, said decoder having means for providing an improved reconstructed signal, comprising: means for providing a partially reconstructed signal based on information received from the encoder; means for receiving from the encoder N subband energy values E k , where k varies from 1-N, each E k based on the energy present in a particular spectral subband of the original input signal; means for providing N noise/waveform fill signals, each having an energy value E' k , including means for providing the E' k , comprising: means for computing values A, B which minimize ##EQU4## means for computing N values Z k based on E k -(Ak+B), where k varies from 1-N; means for identifying the largest Z k (Z k |max); means for computing N values E' k based on E k -ξ(Z k |max -Z k ), where k varies from 1-N and ξ is a predetermined constant; means for combining the noise/waveform fill signals with said partially reconstructed signal.

Claim 6

A subband coding system including an encoder having an input signal and a decoder, said decoder having means for providing an improved reconstructed signal, comprising: means for providing a partially reconstructed signal based on information received from the encoder; means for receiving from the encoder N subband energy values E k , where k varies from 1-N, each E k based on the energy present in a particular spectral subband of the original input signal; means for providing N noise/waveform fill signals, each having an energy value E' k , including means for providing the E' k , comprising: means for computing values A, B which minimize ##EQU4## means for computing N values Z k based on E k -(Ak+B), where k varies from 1-N; means for identifying the largest Z k (Z k |max); means for computing N values E' k based on E k -ξ(Z k |max -Z k ), where k varies from 1-N and ξ is a predetermined constant; means for combining the noise/waveform fill signals with said partially reconstructed signal.

Claim 7

The subband coding system of claim 4 wherein ξ is generally=0.3.

Claim 8

The subband coding system of claim 4 wherein N=11.

Claim 9

A subband coding system including an encoder having an input signal and a decoder, said decoder being arranged for providing an improved reconstructed signal according to the method comprising the following steps: (a) providing a partially reconstructed signal based on information received from the encoder; (b) receiving from the encoder N subband energy values E k , where k varies from 1-N, each E k based on the energy present in a particular spectral subband of the original input signal; (c) providing N noise/waveform fill signals, each having an energy value E' k , where the E' k is provided by the following steps: (c 1 ) computing values A, B which minimize ##EQU5## (c 2 ) computing N values Z k based on E k -(Ak+B), where k varies from 1-N; (c 3 ) identifying the largest Z k (Z k |max); (c 4 ) computing N values E' k based on E k -ξ(Z k |max -Z k ), where k varies from 1-N and ξ is a predetermined constant; (d) combining the noise/waveform fill signals with said partially reconstructed signal.

Claim 10

A subband coding system including an encoder having an input signal and a decoder, said decoder being arranged for providing an improved reconstructed signal according to the method comprising the following steps: (a) providing a partially reconstructed signal based on information received from the encoder; (b) receiving from the encoder N subband energy values E k , where k varies from 1-N, each E k based on the energy present in a particular spectral subband of the original input signal; (c) providing N noise/waveform fill signals, each having an energy value E' k , where the E' k is provided by the following steps: (c 1 ) computing values A, B which minimize ##EQU5## (c 2 ) computing N values Z k based on E k -(Ak+B), where k varies from 1-N; (c 3 ) identifying the largest Z k (Z k |max); (c 4 ) computing N values E' k based on E k -ξ(Z k |max -Z k ), where k varies from 1-N and ξ is a predetermined constant; (d) combining the noise/waveform fill signals with said partially reconstructed signal.

Claim 11

The subband coding system of claim 7 wherein ξ is generally=0.3.

Claim 12

The subband coding system of claim 7 wherein N=11.

Claim 13

A subband coding system including an encoder having an input signal and a decoder, said decoder having a computing means such as a microprocessor or a digital signal processor programmed for providing an improved reconstructed signal according to the method comprising the following steps: (a) providing a partially reconstructed signal based on information received from the encoder; (b) receiving from the encoder N subband energy values E k , where k varies from 1-N, each E k based on the energy present in a particular spectral subband of the original input signal; (c) providing N noise/waveform fill signals, each having an energy value E' k , where the E' k is provided by the following steps: (c 1 ) computing values A, B which minimize ##EQU6## (c 2 ) computing N values Z k based on E k -(Ak+B), where k varies from 1-N; (c 3 ) identifying the largest Z k (Z k |max); (c 4 ) computing N values E' k based on E k -ξ(Z k |max -Z k ), where k varies from 1-N and ξ is a predetermined constant; (d) combining the noise/waveform fill signals with said partially reconstructed signal.

Claim 14

A subband coding system including an encoder having an input signal and a decoder, said decoder having a computing means such as a microprocessor or a digital signal processor programmed for providing an improved reconstructed signal according to the method comprising the following steps: (a) providing a partially reconstructed signal based on information received from the encoder; (b) receiving from the encoder N subband energy values E k , where k varies from 1-N, each E k based on the energy present in a particular spectral subband of the original input signal; (c) providing N noise/waveform fill signals, each having an energy value E' k , where the E' k is provided by the following steps: (c 1 ) computing values A, B which minimize ##EQU6## (c 2 ) computing N values Z k based on E k -(Ak+B), where k varies from 1-N; (c 3 ) identifying the largest Z k (Z k |max); (c 4 ) computing N values E' k based on E k -ξ(Z k |max -Z k ), where k varies from 1-N and ξ is a predetermined constant; (d) combining the noise/waveform fill signals with said partially reconstructed signal.

Claim 15

The subband coding system of claim 10 wherein ξ is generally=0.3.

Claim 16

The subband coding system of claim 10 wherein N=11.

Claim 17

In a subband coding system including an encoder having an input signal and a decoder, a method for operating a computer such as a microprocessor or a digital signal processor for providing an improved reconstructed signal at the decoder, the method comprising the following steps: (a) providing a partially reconstructed signal based on information received from the encoder; (b) receiving from the encoder N subband energy values E k , where k varies from 1-N, each E k based on the energy present in a particular spectral subband of the original input signal; (c) providing N noise/waveform fill signals, each having an energy value E' k , where the E' k is provided by the following steps; (c 1 ) computing values A, B which minimize ##EQU7## (c 2 ) computing N values Z k based on E k -(Ak+B), where k varies from 1-N; (c 3 ) identifying the largest Z k (Z k | max ); (c 4 ) computing N values E' k based on E k -ξ(Z k | max -Z k ), where k varies from 1-N and ξ is a predetermined constant; (d) combining the noise/waveform fill signals with said partially reconstructed signal.

Claim 18

In a subband coding system including an encoder having an input signal and a decoder, a method for operating a computer such as a microprocessor or a digital signal processor for providing an improved reconstructed signal at the decoder, the method comprising the following steps: (a) providing a partially reconstructed signal based on information received from the encoder; (b) receiving from the encoder N subband energy values E k , where k varies from 1-N, each E k based on the energy present in a particular spectral subband of the original input signal; (c) providing N noise/waveform fill signals, each having an energy value E' k , where the E' k is provided by the following steps; (c 1 ) computing values A, B which minimize ##EQU7## (c 2 ) computing N values Z k based on E k -(Ak+B), where k varies from 1-N; (c 3 ) identifying the largest Z k (Z k | max ); (c 4 ) computing N values E' k based on E k -ξ(Z k | max -Z k ), where k varies from 1-N and ξ is a predetermined constant; (d) combining the noise/waveform fill signals with said partially reconstructed signal.

Claim 19

The method of claim 13 wherein ξ is generally=0.3.

Claim 20

The method of claim 13 wherein N=1.