Method and arrangement for scalable low-complexity coding/decoding
Uloženo v:
| Název: | Method and arrangement for scalable low-complexity coding/decoding |
|---|---|
| Patent Number: | 9,524,727 |
| Datum vydání: | December 20, 2016 |
| Appl. No: | 14/405707 |
| Application Filed: | November 13, 2012 |
| Abstrakt: | In a quantization method for quantizing a received excitation signal in a communication system performing the steps of re-shuffling S301 the elements of the received excitation signal to provide a re-shuffled excitation signal; coding S302 the re-shuffled excitation signal with a variable bit-rate algorithm to provide a coded excitation signal; and reassigning S303 codewords of the coded excitation signal if a number of used bits exceeds a predetermined fixed bit rate requirement to provide a quantized excitation signal. |
| Inventors: | TELEFONAKTIEBOLAGET L M ERICSSON (PUBL) (Stockholm, SE) |
| Assignees: | Telefonaktiebolaget LM Ericsson (publ) (Stockholm, SE) |
| Claim: | 1. A quantization method for quantizing a received excitation signal in a communication system, comprising: re-shuffling the elements of the received excitation signal to provide a re-shuffled excitation signal; coding the re-shuffled excitation signal with a variable bit-rate algorithm to provide a coded excitation signal, wherein the coded excitation signal is quantized with respect to a plurality of amplitude level; and reassigning codewords of the coded excitation signal if a number of used bits exceeds a predetermined fixed bit rate requirement to provide a quantized excitation signal, wherein: reassigning codewords comprises modifying codeword lengths based on probabilities for each of the plurality of amplitude levels occurring, and a shorter codeword length corresponds with a higher probability of an amplitude level occurring. |
| Claim: | 2. The quantization method according to claim 1 , comprising performing said coding step on the elements of the received excitation signal and prior to performing said re-shuffling step on the coded excitation signal. |
| Claim: | 3. The quantization method according to claim 1 , wherein coding the re-shuffled excitation signal comprises both SQ coding and entropy coding the re-shuffled excitation signal. |
| Claim: | 4. The quantization method according to claim 3 , further comprising inversely re-shuffling the coded excitation signal after reassigning codewords of the coded excitation signal. |
| Claim: | 5. An encoding method in a communication system, comprising: extracting a representation of a spectral envelope of an audio signal; providing and quantizing an excitation signal based on at least the representation and the audio signal, the quantization being performed according to claim 1 ; providing and quantizing a gain for the audio signal based on at least the excitation signal, the provided representation and the audio signal; transmitting quantization indices for at least the quantized gain and the quantized excitation signal to a decoder. |
| Claim: | 6. The encoding method according to claim 5 , wherein: encoding takes place in the time domain; extracting the representation of the spectral envelope comprises extracting and quantizing a set of auto regression coefficients for the audio signal, wherein the set of auto regression coefficients comprise the representation of the spectral envelope of the audio signal; providing and quantizing the excitation signal is based on at least the quantized auto regression coefficients and the audio signal; providing and quantizing the gain is based on at least the excitation signal, the quantized AR coefficients, and the audio signal; transmitting quantization indices comprises transmitting quantization indices for the auto regression coefficients, the excitation signal, and the gain to the decoder. |
| Claim: | 7. The encoding method according to claim 5 , wherein: encoding takes place in the frequency domain; extracting the representation of the spectral envelope comprises extracting a set of band gains for the audio signal, wherein the band gains comprise the representation of the spectral envelope of the audio signal; providing and quantizing the excitation signal is based on at least the extracted band gains and the audio signal; providing and quantizing the set of band gains is based on at least the excitation signal, the extracted band gains, and the audio signal; transmitting quantization indices comprises transmitting quantization indices for the band gain coefficients and the excitation signal to the decoder. |
| Claim: | 8. A quantizer for quantizing a received excitation signal a communication system, comprising one or more processors configured for: re-shuffling the elements of the received excitation signal to provide a re-shuffled excitation signal; coding the re-shuffled excitation signal with a variable bit-rate algorithm to provide a coded excitation signal, wherein the coded excitation signal is quantized with respect to a plurality of amplitude levels; and reassigning codewords of the coded excitation signal if a number of used bits exceeds a predetermined fixed bit rate requirement, wherein: reassigning codewords comprises modifying codeword lengths based on probabilities for each of the plurality of amplitude levels occurring, and a shorter codeword length corresponds with a higher probability of an amplitude level occurring. |
| Claim: | 9. The quantizer according to claim 8 , wherein the one or more processors are configured for: SQ coding the re-shuffled excitation signal, and entropy coding the SQ coded re-shuffled excitation signal. |
| Claim: | 10. The quantizer according to claim 8 , wherein the one or more processors are configured for inversely re-shuffling the elements of the coded excitation signal after reassigning codewords of the coded excitation signal. |
| Claim: | 11. An encoder comprising one or more processors configured for: implementing a quantizer according to claim 8 , wherein the quantizer is configured for providing and quantizing an excitation signal based on at least a representation of a spectral envelope of an audio signal and the audio signal; extracting the representation of the spectral envelope of the audio signal; providing and quantizing a gain based on at least the excitation signal, the provided representation and the audio signal; and transmitting quantization indices for at least the quantized gain and the quantized excitation signal to a decoder. |
| Claim: | 12. The encoder according to claim 11 , wherein the one or more processors are configured for: operating in the time domain; extracting and quantizing AR coefficients as the representation of the spectral envelope of the audio signal; providing and quantizing an excitation signal based on at least the quantized auto regression coefficients and the received audio signal; providing and quantizing a gain based on at least the excitation signal, the quantized auto regression coefficients, and the received audio signal; transmitting quantization indices for the auto regression coefficients, the excitation signal, and the gain to a decoder. |
| Claim: | 13. The encoder according to claim 11 , wherein the one or more processors are configured for: operating in the frequency domain; extracting a set of band gains as the representation of the spectral envelope for the audio signal; providing and quantizing an excitation signal based on at least the extracted band gains and the received audio signal; quantizing the set of band gains based on at least the excitation signal, the extracted band gains, and the received audio signal; transmitting quantization indices for the band gain coefficients and the excitation signal to a decoder. |
| Claim: | 14. A user terminal comprising a quantizer according to claim 8 . |
| Claim: | 15. A de-quantization method for reconstructing an excitation signal in a communication system, comprising: entropy decoding a received quantized excitation signal, wherein: the received quantized excitation signal is quantized with respect to a plurality of amplitude levels, the length of codewords of the received quantized excitation signal are based on probabilities for each of the plurality of amplitude levels occurring, and a shorter codeword length corresponds with a higher probability of an amplitude level occurring; SQ decoding the entropy decoded excitation signal to provide the reconstructed excitation signal, and inversely re-shuffling the elements of the reconstructed excitation signal. |
| Claim: | 16. The method according to claim 15 , wherein inversely re-shuffling step is performed when the elements of the reconstructed excitation signal have been previously re-shuffled in a quantizer. |
| Claim: | 17. A decoder comprising one or more processors configured for: implementing a de-quantizer according to claim 16 , wherein the de-quantizer, is further configured for generating a reconstructed excitation signal based on received quantization indices for the excitation signal; generating and spectrally shaping a reconstructed representation of a spectral envelope of an audio signal based at least on the generated reconstructed excitation signal and a received quantized representation of a spectral envelope of the audio signal to provide a synthesized audio signal; scaling the synthesized audio signal based on received quantization indices for a gain to provide a decoded audio signal. |
| Claim: | 18. The decoder according to claim 17 , wherein the one or more processors are configured for: operating in the time domain; generating and spectrally shaping the reconstructed representation of the spectral envelope based on the generated reconstructed excitation signal and received quantizer auto regression coefficients as the representation of the spectral envelope, and scaling the synthesized audio signal based on received quantization indices for a gain to provide the decoded audio signal. |
| Claim: | 19. The decoder according to claim 17 , wherein the one or more processors are configured for: operating in the frequency domain; generating and spectrally shaping the reconstructed representation of the spectral envelope based on the generated reconstructed excitation signal, and scaling the synthesized audio signal based on received quantization indices for band gains to provide the decoded audio signal. |
| Claim: | 20. A decoding method in a communication system, comprising: generating a reconstructed excitation signal for an audio signal based on received quantization indices for an excitation signal according to claim 15 ; generating and spectrally shaping a reconstructed representation of the spectral envelope of the audio signal based on at least the generated reconstructed signal and received quantized representation of a spectral envelope of the audio signal to provide a synthesized audio signal; scaling the synthesized audio signal based on received quantization indices for a gain to provide a decoded audio signal. |
| Claim: | 21. The decoding method according to claim 20 , wherein: the method operates in the time domain; generating and spectrally shaping the reconstructed representation of the spectral envelope is based on the reconstructed excitation signal and received quantized auto regression coefficients as the representation of the spectral envelope; and scaling the synthesized audio signal is based on received quantization indices for a gain to provide the decoded audio signal. |
| Claim: | 22. The decoding method according to claim 20 , wherein: the method operates in the frequency domain; generating and spectrally shaping the reconstructed representation of the spectral envelope is based on the generated reconstructed excitation signal; and scaling the synthesized audio signal based on received quantization indices for band gains to provide the decoded audio signal. |
| Claim: | 23. A de-quantizer for reconstructing excitation signals in a communication system, comprising one or more processors configured for: entropy decoding a received quantized excitation signal, wherein: the received quantized excitation signal is quantized with respect to a plurality of amplitude levels, the length of codewords of the received quantized excitation signal are based on probabilities for each of the plurality of amplitude levels occurring, and a shorter codeword length corresponds with a higher probability of an amplitude level occurring; SQ decoding the entropy decoded excitation signal to provide a reconstructed excitation signal, and inversely re-shuffling elements of the reconstructed excitation signal. |
| Claim: | 24. The de-quantizer according to claim 23 , wherein the one or more processors are configured to inversely re-shuffling elements of the reconstructed excitation signal when the elements of the reconstructed excitation signal have been previously re-shuffled in an encoder. |
| Claim: | 25. A base station terminal comprising a de-quantizer according to claim 23 . |
| Patent References Cited: | 5748839 May 1998 Serizawa 5825311 October 1998 Kataoka 6052661 April 2000 Yamaura RE38279 October 2003 Kataoka 6928406 August 2005 Ehara 7698132 April 2010 Kandhadai 2004/0117176 June 2004 Kandhadai 2005/0004793 January 2005 Ojala 2009/0234653 September 2009 Kawashima 2009/0248424 October 2009 Koishida 2010/0046626 February 2010 Tu 2014/0343953 November 2014 Geiger 2 463 974 April 2010 |
| Other References: | JM Valin Mozilla Corporation K Vos Skype Technologies S A T Terriberry Mozilla Corporation: “Definition of the Opus Audio Codec; draft-ietf-codec-opus-13.txt”, Definition of the Opus Audio Codec; Draft-IETF-Codec-Opus-13.txt, Internet Engineering Task Force, IETF May 16, 2012. cited by applicant International Search Report for International application No. PCT/EP2012/072491 Mar. 8, 2013. cited by applicant PCT International Preliminary Report on Patentability for International application No. PCT/EP2012/072491 Oct. 7, 2014. cited by applicant |
| Primary Examiner: | Abebe, Daniel |
| Attorney, Agent or Firm: | Baker Botts, LLP |
| Přístupové číslo: | edspgr.09524727 |
| Databáze: | USPTO Patent Grants |
| Abstrakt: | In a quantization method for quantizing a received excitation signal in a communication system performing the steps of re-shuffling S301 the elements of the received excitation signal to provide a re-shuffled excitation signal; coding S302 the re-shuffled excitation signal with a variable bit-rate algorithm to provide a coded excitation signal; and reassigning S303 codewords of the coded excitation signal if a number of used bits exceeds a predetermined fixed bit rate requirement to provide a quantized excitation signal. |
|---|