1、 TIA-102.BABA-A (Revision of TIA-102.BABA) February 2014Project 25 Vocoder Description ANSI/TIA-102.BABA-A-2014 APPROVED: JANUARY 27, 2014 NOTICE TIA Engineering Standards and Publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and purch
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4、ance with the American National Standards Institute (ANSI) patent policy. By such action, TIA does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the Standard or Publication. This Standard does not purport to address all safety problems a
5、ssociated with its use or all applicable regulatory requirements. It is the responsibility of the user of this Standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations before its use. Any use of trademarks in this document are for inf
6、ormation purposes and do not constitute an endorsement by TIA or this committee of the products or services of the company. (From Project No. ANSI/TIA-PN-102.BABA-A, formulated under the cognizance of the TIA TR-8 Mobile and Personal Private Radio Standards, TR-8.4 Subcommittee on Vocoders). Publish
7、ed by TELECOMMUNICATIONS INDUSTRY ASSOCIATION Technology (b) there is no assurance that the Document will be approved by any Committee of TIA or any other body in its present or any other form; (c) the Document may be amended, modified or changed in the standards development or any editing process.
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11、r provided in the Manual have been complied with as respects the Document or its contents. If the Document contains one or more Normative References to a document published by another organization (“other SSO”) engaged in the formulation, development or publication of standards (whether designated a
12、s a standard, specification, recommendation or otherwise), whether such reference consists of mandatory, alternate or optional elements (as defined in the TIA Engineering Manual, 4thedition) then (i) TIA disclaims any duty or obligation to search or investigate the records of any other SSO for IPR o
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15、signs or services or any claims of compliance with the contents of the Document. ALL WARRANTIES, EXPRESS OR IMPLIED, ARE DISCLAIMED, INCLUDING WITHOUT LIMITATION, ANY AND ALL WARRANTIES CONCERNING THE ACCURACY OF THE CONTENTS, ITS FITNESS OR APPROPRIATENESS FOR A PARTICULAR PURPOSE OR USE, ITS MERCH
16、ANTABILITY AND ITS NONINFRINGEMENT OF ANY THIRD PARTYS INTELLECTUAL PROPERTY RIGHTS. TIA EXPRESSLY DISCLAIMS ANY AND ALL RESPONSIBILITIES FOR THE ACCURACY OF THE CONTENTS AND MAKES NO REPRESENTATIONS OR WARRANTIES REGARDING THE CONTENTS COMPLIANCE WITH ANY APPLICABLE STATUTE, RULE OR REGULATION, OR
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18、 WITHOUT LIMITATION ANY AND ALL INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES (INCLUDING DAMAGES FOR LOSS OF BUSINESS, LOSS OF PROFITS, LITIGATION, OR THE LIKE), WHETHER BASED UPON BREACH OF CONTRACT, BREACH OF WARRANTY, TORT (INCLUDING NEGLIGENCE), PRODUCT LIABILITY OR OTHERWISE, EVEN IF A
19、DVISED OF THE POSSIBILITY OF SUCH DAMAGES. THE FOREGOING NEGATION OF DAMAGES IS A FUNDAMENTAL ELEMENT OF THE USE OF THE CONTENTS HEREOF, AND THESE CONTENTS WOULD NOT BE PUBLISHED BY TIA WITHOUT SUCH LIMITATIONS. TIA-102.BABA-A i Foreword: (This foreword is not part of the standard) This Vocoder Stan
20、dard (102BABA), titled Vocoder Description, has been developed with inputs from the APCO Project 25 Interface Committee (APIC), the APIC Vocoder Task Group, and TIA Industry Members. This Standard will be maintained by TR-8.4. This document has been submitted to APCO/NASTD/FED by the Telecommunicati
21、ons Industry Association (TIA), as provided for in a Memorandum of Understanding (MOU) dated December, 1993. That MOU provides that APCO/NASTD/FED will devise a Common System Standard for digital public safety communications (the Standard), and that TIA shall provide technical assistance in the deve
22、lopment of documentation for the Standard. The symbol “P25” or the wording “Project 25” appearing on the cover sheet of this document when published or in the title of any TIA-102 document or Telecommunications Service Bulletin (TSB) referenced herein, that indicates the APCO/NASTD/FED Project 25 St
23、eering Committee has adopted the document as part of the Standard. The appearance of the abbreviation “P25” or the wording “Project 25” on the cover sheet of this document or in the title of any document referenced herein does not limit the applicability of the information contained in this document
24、 to “P25” or “Project 25” implementations exclusively. This document is being published to provide technical information on the emerging digital techniques for Land Mobile Radio Service. This document defines vocoders for land mobile radios capable of 12.5 kHz efficiency and/or 6.25 kHz efficiency.
25、The readers attention is called to the possibility that compliance with this Standard may require the use of one or more inventions covered by patent rights. By publication of this Standard, no position is taken with respect to the validity of those claims or any patent rights in connection therewit
26、h. The patent holders so far identified have, however, led statements of willingness to grant licenses under those rights on reasonable and nondiscriminatory terms and conditions to applicants desiring to obtain such licenses. Details may be obtained from the publisher. TIA-102.BABA-A ii Vocoder Des
27、cription Digital Voice Systems Inc. (DVSI) claims certain rights, including patent rights, in the Improved Multi-Band Excitation (IMBE) voice coding algorithm described in this document and elsewhere. Any use of this technology requires a separate written license from DVSI. DVSI grants a free, irrev
28、ocable license to the Telecommunications Industry Association (TIA) to incorporate text contained in this contribution and any modifications thereof in the creation of a TIA standards publication; to copyright in TIAs name any TIA standards publication even though it may include portions of this con
29、tribution; and at TIAs sole discretion to permit others to reproduce in whole or in part the resulting TIA standards publication. Note: The users attention is called to the possibility that compliance with this standard may require use of one or more inventions covered by patent rights. By publicati
30、on of this standard, no position is taken with respect to the validity of those claims or of any patent rights in connection therewith. The patent holders so far identified have, however, filed statements of willingness to grant licenses under those rights on reasonable and nondiscriminatory terms a
31、nd conditions to applicants desiring to obtain such licenses. Details may be obtained from the publisher. TIA-102.BABA-A iii Contents 1 Scope . 1 2 Introduction . 2 3 Multi-Band Excitation Speech Model . 5 4 Speech Input / Output Requirements . 7 5 Speech Analysis 9 5.1 Pitch Estimation . 11 5.1.1 D
32、etermination of E(P) . 12 5.1.2 Pitch Tracking 13 5.1.3 Look-Back Pitch Tracking 14 5.1.4 Look-Ahead Pitch Tracking 14 5.1.5 Pitch Refinement . 16 5.2 Voiced / Unvoiced Determination 17 5.3 Estimation of the Spectral Amplitudes . 19 6 Full-Rate Parameter Encoding and Decoding 21 6.1 Fundamental Freq
33、uency Encoding and Decoding . 21 6.2 Voiced / Unvoiced Decision Encoding and Decoding . 23 6.3 Spectral Amplitudes Encoding . 24 6.3.1 Encoding the Gain Vector 27 6.3.2 Encoding the Higher Order DCT Coefficients 27 6.4 Spectral Amplitudes Decoding . 29 6.4.1 Decoding the Gain Vector 29 6.4.2 Decodin
34、g the Higher Order DCT Coefficients 30 6.5 Synchronization Encoding and Decoding 32 7 Full-Rate Bit Manipulations . 33 7.1 Bit Prioritization 34 7.2 Encryption 35 7.3 Error Control Coding . 36 7.4 Bit Modulation 38 7.5 Bit Interleaving . 39 7.6 Error Estimation 39 7.7 Frame Repeats 40 7.8 Frame Muti
35、ng 41 8 Full-Rate Spectral Amplitude Enhancement 42 TIA-102.BABA-A iv 9 Adaptive Smoothing . 44 10 Full-Rate Parameter Encoding Example 46 11 Speech Synthesis . 51 11.1 Speech Synthesis Notation 51 11.2 Unvoiced Speech Synthesis 52 11.3 Voiced Speech Synthesis 53 12 Additional Notes 56 13 Half-Rate
36、Vocoder Quantization . 57 13.1 Fundamental Frequency Encoding and Decoding 58 13.2 Voiced / Unvoiced Decision Encoding and Decoding 59 13.3 Spectral Amplitudes Encoding 59 13.3.1 Encoding the PRBA Vector . 62 13.3.2 Encoding the Higher Order DCT Coefficients . 62 13.4 Spectral Amplitudes Decoding 63
37、 13.4.1 Decoding the Gain 63 13.4.2 Decoding the PRBA Vector . 63 13.4.3 Decoding the Higher Order DCT Coefficients . 64 14 Half-Rate Bit Manipulations . 66 14.1 Bit Prioritization . 67 14.2 Error Control Coding . 68 14.3 Bit Modulation . 69 14.4 Bit Interleaving 70 14.5 Error Estimation . 70 14.6 F
38、rame Repeats . 71 14.7 Frame Muting . 71 15 Half-Rate Spectral Amplitude Enhancement . 72 16 Tone Frames 73 16.1 Tone Detection . 73 16.2 Tone Transmission 74 16.3 Tone Regeneration . 75 17 Parametric Rate Conversion . 76 Annex A Variable Initialization 78 Annex B Initial Pitch Estimation Window . 7
39、9 Annex C Pitch Refinement Window . 81 Annex D FIR Low Pass Filter . 83 TIA-102.BABA-A v Annex E Gain Quantizer Levels 84 Annex F Bit Allocation and Step Size for Transformed Gain Vector . 85 Annex G Bit Allocation for Higher Order DCT Coefficients 89 Annex H Bit Frame Format . 102 Annex I Speech Sy
40、nthesis Window . 103 Annex J Log Magnitude Prediction Residual Block Lengths . 105 Annex K Flow Charts . 106 Annex L (Normative) Fundamental Frequency Quantization Table . 127 Annex M (Normative) V/UV Quantization Vectors 128 Annex N (Normative) Log Magnitude Prediction Residual Block Lengths . 129
41、Annex O (Normative) Gain Quantizer Levels 130 Annex P (Normative) PRBA24 Vector Quantizer Levels 131 Annex Q (Normative) PRBA58 Vector Quantizer Levels 137 Annex R (Normative) Quantization Tables for Higher Order Coefficients . 140 Annex S (Normative) Bit Frame Format . 143 Annex T (Normative) Tone
42、Frame Parameters . 144 Informative References 145 TIA-102.BABA-A vi List of Figures Figure 1 Improved Multi-Band Excitation Speech Coder . 2 Figure 2 Comparison of Traditional and MBE Speech Models . 6 Figure 3 Analog Front End . 7 Figure 4 Analog Input / Output Filter Mask . 8 Figure 5 IMBE Speech
43、Analysis Algorithm 9 Figure 6 High Pass Filter Frequency Response at 8 kHz Sampling Rate 10 Figure 7 Relationship between Speech Frames 11 Figure 8 Window Alignment . 12 Figure 9 Initial Pitch Estimation 13 Figure 10 Pitch Refinement . 16 Figure 11 IMBE Voiced/Unvoiced Determination . 17 Figure 12 I
44、MBE Frequency Band Structure 19 Figure 13 IMBE Spectral Amplitude Estimation . 19 Figure 14 Fundamental Frequency Encoding and Decoding 23 Figure 15 V/UV Decision Encoding and Decoding . 24 Figure 16 Encoding of the Spectral Amplitudes . 24 Figure 17 Prediction Residual Blocks for L = 34 26 Figure 1
45、8 Formation of Gain Vector 26 Figure 19 Decoding of the Spectral Amplitudes . 29 Figure 20 Encoder Bit Manipulations . 33 Figure 21 Decoder Bit Manipulations . 34 Figure 22 Priority Scanning of b3 through bL+1 35 Figure 23 Formation of Code Vectors v0 through v3 36 Figure 24 Formation of Code Vector
46、s v4 through v7 37 Figure 25 Parameter Enhancement and Smoothing . 45 Figure 26 IMBE Speech Synthesis . 51 Figure 27 Half-Rate Code Vector Construction . 66 TIA-102.BABA-A vii List of Tables Table 1 Bit Allocation Among Model Parameters 21 Table 2 Eight Bit Binary Representation . 21 Table 3 Uniform
47、 Quantizer Step Size for Higher Order DCT Coefficients 28 Table 4 Standard Deviation of Higher Order DCT Coefficients 28 Table 5 Division of Prediction Residuals into Blocks in Encoding Example . 46 Table 6 Example Bit Allocation and Step Size for the Transformed Gain Vector 46 Table 7 Example Bit A
48、llocation and Step Size for Higher Order DCT Coefficients . 47 Table 8 Construction of ui in Encoding Example (1 of 3) 48 Table 9 Construction of ui in Encoding Example (2 of 3) 49 Table 10 Construction of ui in Encoding Example (3 of 3) . 50 Table 11 Breakdown of Algorithmic Delay . 56 Table 12 Hal
49、f-Rate Voice/Silence Frame Bit Allocation 57 Table 13 Seven Bit Binary Representation . 58 Table 14 Vocoder Frame Types . 58 Table 15 Construction of Bit Vector u0 . 67 Table 16 Construction of Bit Vector u1 . 67 Table 17 Construction of Bit Vector u2 . 67 Table 18 Construction of Bit Vector u3 . 68 Table 19 Half-Rate Vocoder: Supported Tone Signals . 74 Table 20 Tone Frame Format . 75 Table 21 Frame Type Conversion . 76 TIA-102.BABA-A viii This page intentionally left blank.TIA-102.BABA-A 1 1 Scope This document serves as the interoperability specification for the Dual-Rate Vocoder e
