TIA-102 BABG-2010 Project 25 Enhanced Vocoder Methods of Measurement for Performance (Includes Access to Additional Content)《项目25 增强型编解码器性能测量方法 可访问其他内容》.pdf

《TIA-102 BABG-2010 Project 25 Enhanced Vocoder Methods of Measurement for Performance (Includes Access to Additional Content)《项目25 增强型编解码器性能测量方法 可访问其他内容》.pdf》由会员分享，可在线阅读，更多相关《TIA-102 BABG-2010 Project 25 Enhanced Vocoder Methods of Measurement for Performance (Includes Access to Additional Content)《项目25 增强型编解码器性能测量方法 可访问其他内容》.pdf（33页珍藏版）》请在麦多课文档分享上搜索。

1、 Access to Additional Content for TIA-102.BABG, Dated: March 2010 (Click here to view the publication) This Page is not part of the original publication This page has been added by IHS as a convenience to the user in order to provide access to additional content as authorized by the Copyright holder

2、 of this document Click the link(s) below to access the content and use normal procedures for downloading or opening the files. TIA-102.BABG Extra Files Information contained in the above is the property of the Copyright holder and all Notice of Disclaimer (b) there is no assurance that the Document

3、 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. The use or practice of contents of this Document may involve the use of intellectual property rights

4、 (“IPR”), including pending or issued patents, or copyrights, owned by one or more parties. TIA makes no search or investigation for IPR. When IPR consisting of patents and published pending patent applications are claimed and called to TIAs attention, a statement from the holder thereof is requeste

5、d, all in accordance with the Manual. TIA takes no position with reference to, and disclaims any obligation to investigate or inquire into, the scope or validity of any claims of IPR. TIA will neither be a party to discussions of any licensing terms or conditions, which are instead left to the parti

6、es involved, nor will TIA opine or judge whether proposed licensing terms or conditions are reasonable or non-discriminatory. TIA does not warrant or represent that procedures or practices suggested or provided in the Manual have been complied with as respects the Document or its contents. If the Do

7、cument 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 as a standard, specification, recommendation or otherwise), whether such reference consists of mandat

8、ory, 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 or letters of assurance relating to any such Normative Reference; (ii) TIAs policy of encouragement o

9、f voluntary disclosure (see Engineering Manual Section 6.5.1) of Essential Patent(s) and published pending patent applications shall apply; and (iii) Information as to claims of IPR in the records or publications of the other SSO shall not constitute identification to TIA of a claim of Essential Pat

10、ent(s) or published pending patent applications. TIA does not enforce or monitor compliance with the contents of the Document. TIA does not certify, inspect, test or otherwise investigate products, designs or services or any claims of compliance with the contents of the Document. ALL WARRANTIES, EXP

11、RESS 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 MERCHANTABILITY AND ITS NONINFRINGEMENT OF ANY THIRD PARTYS INTELLECTUAL PROPERTY RIGHTS. TIA EXPRESSLY D

12、ISCLAIMS 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 THE SAFETY OR HEALTH EFFECTS OF THE CONTENTS OR ANY PRODUCT OR SERVICE REFERRED TO IN THE DOCUMENT O

13、R PRODUCED OR RENDERED TO COMPLY WITH THE CONTENTS. TIA SHALL NOT BE LIABLE FOR ANY AND ALL DAMAGES, DIRECT OR INDIRECT, ARISING FROM OR RELATING TO ANY USE OF THE CONTENTS CONTAINED HEREIN, INCLUDING WITHOUT LIMITATION ANY AND ALL INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES (INCLUDING DA

14、MAGES 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 ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. THE FOREGOING NEGATION OF DAMAGES IS A FUNDAMENTAL ELEMEN

15、T OF THE USE OF THE CONTENTS HEREOF, AND THESE CONTENTS WOULD NOT BE PUBLISHED BY TIA WITHOUT SUCH LIMITATIONS. TIA-102.BABG Foreword This document has been submitted to PROJECT 25 by the Telecommunications Industry Association (TIA), as provided for in a Memorandum of Understanding (MOU) dated Dece

16、mber 1993. That MOU provides that PROJECT 25 will devise a Common System Standard for digital public safety communications (the Standard), and that TIA shall provide technical assistance in the development of documentation for the Standard. This document has been developed with inputs from the TIA P

17、roject 25, Interface Committee (APIC), the APIC Vocoder Task Group, and TIA industry members. This document is being published because it is felt that there is an urgent need for Project 25 to set a standard for spectrum efficiency equivalent to 6.25 kHz as stated by the FCC. Technology choices for

18、the TDMA Two Slot Air Interface are based on Project 25 Steering Committee decisions regarding the vocoder, modulations and over all bit rate made at their meeting of 27-April-2007. iTIA-102.BABG TABLE OF CONTENTS 1. Introduction 1 1.1 Scope 1 1.2 Objectives 1 1.3 Standard Definitions 2 1.3.1 Standa

19、rd Average Speech Level . 2 1.3.2 Standard Vocoder Sample Rate 3 1.3.3 Standard Audio Sample Rate 3 1.3.4 Standard Reference Encoder. 3 1.3.5 Standard Reference Decoder. 3 1.3.6 Standard Test Tone . 4 1.3.7 Standard Decibel Level Units . 4 1.4 Standard Test Conditions. 5 1.4.1 Digital Channel Test I

20、nterface 5 1.4.2 Digital Audio Test Interface . 5 1.4.3 Standard Test Sentence Pairs 6 1.4.4 Standard Test Noises. 6 1.5 Characteristics of Test Equipment and Software. 8 1.5.1 WAV Files 8 1.5.2 PCM Files . 8 1.5.3 DAT Files 9 1.5.4 PESQ and MOS LQO Calculation 9 1.5.5 Software Floating Point Precis

21、ion 10 1.5.6 Active Speech Level . 10 1.5.7 Standard Hex Interpolation. 10 1.5.8 Standard Hex Decimation. 11 2. Methods of Measurement 13 2.1 Encoder 13 2.1.1 Audio Sensitivity 13 2.1.2 Noise Reduction 14 2.2 Decoder 15 2.2.1 Audio Output Level 15 2.2.2 Residual Noise 16 3. Performance Specification

22、s . 18 3.1 Encoder 18 3.1.1 Audio Sensitivity 18 3.1.2 Noise Reduction 18 3.2 Decoder 18 3.2.1 Audio Output Level 18 3.2.2 Residual Noise 19 4. References, Abbreviations and History . 20 4.1 Normative References 20 4.2 Informative References. 20 4.3 Abbreviations and Acronyms 20 4.4 Revision History

23、 21 iiTIA-102.BABG 1. Introduction Clause 1 introduces the scope of this standard and its objectives. Clause 1 also introduces standard definitions, standard test conditions, and the characteristics of test equipment (hardware and software) required by this standard. The subsequent two clauses provi

24、de the methods of measurement (clause 2) and performance specifications (clause 3) defined by this standard. The final clause 4 identifies the references and abbreviations used in this standard. 1.1 Scope This document defines the methods of measurement to test performance of the Project 25 (P25) en

25、hanced vocoder. The measurements can then be compared to performance specifications to meet the voice and audio quality objectives defined by this standard for the P25 enhanced vocoder. The P25 enhanced vocoder is a dual-rate vocoder with a full-rate mode for interoperability with P25 Phase 1 equipm

26、ent and a half-rate mode for interoperability with P25 Phase 2 equipment. The test methods and performance specifications are defined for both modes of operation. The test methods and performance specifications are defined for both the encoder and the decoder components of the P25 enhanced vocoder.

27、The P25 enhanced vocoder to be tested shall be applicable to both a radio, and a fixed infrastructure device such as a console. 1.2 Objectives The objectives of the Project 25 standard that were expressed in the APCO Project 25 System and Standards Definition bulletin, TSB-102-A 4.2.2, are as follow

28、s. Obtain maximum radio spectrum efficiency, Ensure competition in system life cycle procurement, Allow effective, efficient and reliable intra-agency and inter-agency communications, Provide user friendly equipment. The APCO Project 25 Statement of Requirements 4.2.1 defines a key goal to achieve s

29、pectrum efficiency in Phase 2 equivalent to four-to-one spectrum utilization in a 25 kHz channel. The Two-Slot TDMA standard for Phase 2 doubles the spectrum efficiency of the Phase 1 standard for 12.5 kHz operation to contribute to the first objective of the Project 25 standard suite and a key goal

30、 of the Statement of Requirements. The Two-Slot TDMA standard also maintains interoperability and compatibility with the Phase 1 standard and is based on the Phase 2, 12.5 kHz TDMA (i.e., two-slot TDMA) requirements defined in the P25 Statement of Requirements to preserve the achievement of the othe

31、r three objectives. In order to meet these objectives, the P25 standards use a vocoder that is defined in the Project 25 Vocoder Description and its associated annexes 4.1.1. A baseline vocoder defined in prior versions of 4.1.1 for Phase 1 is outside the scope of the tests defined in this document.

32、 In general, the baseline vocoder cannot pass the tests defined here, except as may be explicitly indicated in the test description. 1TIA-102.BABG This standard defines performance levels that shall be achieved by P25 enhanced vocoders to achieve voice and audio quality that is equivalent to or bett

33、er than that achievable using vocoders implementing the P25 Enhanced Full-Rate Vocoder (Phase 1 operation) or the P25 Enhanced Half-Rate Vocoders (Phase 2 operation) that have passed the tests defined in 4.2.3 and 4.2.4.12This standard uses the same PC executable vocoder from the MOS tests as a refe

34、rence for interoperation with a candidate vocoder under test. The tests in this standard use the reference vocoder as either the encoder or decoder in a test configuration with the candidate vocoder under test in the complimentary position. Some performance parameters are then measured in the test c

35、onfiguration. For the Encoder tests, the candidate vocoder encoder performance is tested with the reference vocoder decoder. For the Decoder tests, the candidate vocoder decoder performance is tested with the reference vocoder encoder. In this way, the test directly verifies interoperation with the

36、vocoder from the MOS tests. The tests with noise include the sentences from the MOS test as representative signals for the measurement of active speech level and PESQ since these measurements are designed for such speech signals. The noises from the MOS tests are also included in the noise measureme

37、nts. Although the list of noise types used in this testing is wide ranging, it is not an inclusive list of every existing version of that noise type. The performance specification limits are set from measurements with the reference vocoder from the MOS test in both the encoder and decoder positions.

38、 In this way, the test measures the performance of the candidate vocoder as both an encoder and a decoder, independently, to obtain performance equivalent to that of the reference vocoder as tested in the MOS tests. This standard includes standard parameter titles, definitions, test conditions, test

39、 equipment, and test reference software for the purpose of measuring vocoder performance. The tests use WAV files with test sentences and test noises as described in clauses 1.4.3 and 1.4.4, and these files are provided with this standard for use in the measurements. 1.3 Standard Definitions The fol

40、lowing standard definitions are used in the methods of measurement. 1.3.1 Standard Average Speech Level The standard average speech level shall be -22 dBm0. This equates to -28.02 dBov. This is the level used for the MOS tests. 1The relevant performance levels for the P25 Enhanced Full-Rate Vocoder

41、are those established by TIA Engineering Committee TR8.4 (Experiments 1 and 2) and ITS (Experiment 3) in 2003-2005 using Mean Opinion Score testing and documented respectively in 4.2.3 (TSB-102.BABE, Project 25 Vocoder Evaluation, Mean Opinion Score Test, Telecommunication Industry Association, May

42、2007). The relevant performance levels for the P25 Enhanced Half-Rate Vocoder are those defined in 4.2.4 (TSB-102.BABF, Experiment 3 MOS Test Plan for Vocoder Technology for Project 25 Phase 2, Telecommunications Industry Association, 2008). 2This requirement is focused on the enhanced performance l

43、evel and differentiation of non-enhanced from enhanced performance and does not supersede the requirement for audio quality as stated in the P25 Statement of Requirements. 2TIA-102.BABG 1.3.2 Standard Vocoder Sample Rate The standard vocoder sample rate is 8 kHz. This is the sample rate used by the

44、audio input to the standard reference vocoder encoder, and also the sample rate used by the audio output of the standard reference vocoder decoder. This sample rate is also used by the PESQ algorithm. 1.3.3 Standard Audio Sample Rate The standard audio sample rate is 48 kHz. This is the sample rate

45、used by the audio WAV files used as input to the standard reference encoder, and also the sample rate of WAV files used by the audio output of the standard reference decoder. 1.3.4 Standard Reference Encoder The standard reference encoder is test reference software that emulates the operation of an

46、instantiated encoder with the enhanced MBE vocoder. The standard reference encoder consists of two parts. The first part decimates the audio sample rate from 48 kHz to 8 kHz, which is called hex decimation. The second part is the part of the vocoder that operates within the encoder. In many cases, t

47、he audio may already be sampled at 8 kHz, and so the hex decimation part of the encoder may not be necessary. 1.3.4.1 Standard Hex Decimation The first part of the standard reference encoder decimates an input audio WAV file at a 48 kHz sample rate to 8 kHz. A WAV file at a 48 kHz sample rate is cap

48、able of recording noise with spectrum components above the 4 kHz frequency limit that would apply to an 8 kHz sample rate. The input to the vocoder encoder is a PCM file sampled at 8 kHz with 16-bit linear samples. Standard hex decimation algorithms are described in clause 1.5.8. 1.3.4.2 Standard Re

49、ference Vocoder Encoder The second part is the standard reference vocoder encoder. The standard reference vocoder encoder is software that takes a digital representation of the input signal sampled at the standard vocoder sample rate of 8 kHz with 16 bits of precision. The output of the PC executable software is a DAT file representing the encoded audio. The standard reference vocoder encoder is software that shall obtain the performance demonstrated by the MOS tests in 4.2.3 and 4.2.4. The standard reference vocoder encoder also represents the standard fo