1、INTERNATIONALSTANDARDIEC61603-7First edition2003-05Transmission systems of audio and/or video andrelated signals using infra-red radiation Part 7:Digital audio signals for conference andsimilar applicationsReference numberIEC 61603-7:2003(E)LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE
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8、er Service Centre:Email:custserviec.chTel:+41 22 919 02 11Fax:+41 22 919 03 00LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.INTERNATIONALSTANDARDIEC61603-7First edition2003-05Transmission systems of audio and/or video andrelated sign
9、als using infra-red radiation Part 7:Digital audio signals for conference andsimilar applications IEC 2003 Copyright-all rights reservedNo part of this publication may be reproduced or utilized in any form or by any means,electronic ormechanical,including photocopying and microfilm,without permissio
10、n in writing from the publisher.International Electrotechnical Commission,3,rue de Varemb,PO Box 131,CH-1211 Geneva 20,SwitzerlandTelephone:+41 22 919 02 11 Telefax:+41 22 919 03 00 E-mail:inmailiec.ch Web:www.iec.chUFor price,see current cataloguePRICE CODECommission Electrotechnique Internationale
11、International Electrotechnical Commission LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.2 61603-7 IEC:2003(E)CONTENTSFOREWORD.41Scope.52Normative references.53Terms and definitions.54Abbreviations.55Explanation of terms and general i
12、nformation.66System considerations.67Basic system concept.68Protocol.78.1System context.78.2Physical layer.88.3Data link layer.138.4Detailed overview of audio frame structures.159Data protocol.179.1General.179.2Data messages.189.3Data packet structure.21Annex A(normative)Definition of prototype filt
13、er.23Annex B(informative)Example of/f diagram in the user area conference.24Annex C(informative)Provision for future developments.25Bibliography.26Figure 1 System.7Figure 2 Conceptual model.7Figure 3 Band allocation for 6 modulated sub-carriers.8Figure 4 (D)QPSK constellation and differential decodi
14、ng algorithm.9Figure 5 Pulse response of a raised cosine channel filter.10Figure 6 Scrambler.11Figure 7 Block diagram of sub-band APCM encoder.12Figure 8 Quantization of sub-band samples.13Figure 9 Superframe structure.14Figure 10 RS frame structure.14Figure 11 Audio block structure.15Figure 12 CRC
15、calculation.15Figure 13 Audio block structure for medium quality.16Figure 14 Bit-pool sample structure for medium quality.16Figure 15 Audio block structure for high quality.16Figure 16 Bit-pool sample structure for high quality.17Figure 17 Positioning of the data protocol.18LICENSED TO MECON Limited
16、.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.61603-7 IEC:2003(E)3 Figure 18 Data message build-up.18Figure 19 Configuration message structure.19Figure 20 Display message structure for ASCII display data.20Figure 21 Display message structure for bitmap display data.21Figure 22 Segmentation of data messages.21Figure 23 Data packets fitted on to the superframe structure.22Table 1 Sub-carrier centre frequencies.8Table 2 Phase transitions of the differential