Detail of GB/T 26252-2010

Introduction of GB/T 26252-2010

1 Scope This standard specifies the parameters and methods for frequency planning for digital terrestrial television in conformity with GB 20600-2006. This standard is applicable to the coverage network planning of digital terrestrial television broadcasting system in the VHF/UHF bands. 2 Normative References The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding corrections to), or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of these documents are applicable. For undated references, the latest edition of the normative documents referred to applies.GB 3174-1995 "Specifications of PAL-D Television System"GB/T 14433-1993 "Technical Specifications for Coverage Networks of Colour TV Broadcasting"GB 20600-2006 "Framing Structure, Channel Coding, and Modulation for Digital Television Terrestrial Broadcasting System (DTMB)" 3 Terms, Definitions and Abbreviations 3.1 Terms and DefinitionFor the purposes of this standard, the following term and definition applies.3.1.1 Wanted signal The RF signal with information to be received.3.1.2 Unwanted signal Other RF signal irrelevant to the information to be received.3.1.3 RF protection ratio The minimum power ratio of wanted signal to unwanted signal at the normal receiving conditions, generally measured at the receiver inlet and represented by dB. 3.1.4 Time probability The percentage of time when the signal field strength reaches or exceeds a certain given value to the observation time, at any measuring position if the signal varies with the time. 3.1.5 Location probability The percentage of the location where a given value is reached or exceeded to the small measured area (typical value is 100m×100m) when the signal field strength varies with the locations to be measured.3.1.6 Minimum equivalent field strength The minimum field strength to ensure the receiver on the digital terrestrial television can receive the signal normally without other signal interference. Note: The power spectrum density of broadband signal is varied throughout the signal bandwidth, so the "equivalent field strength" is usually adopted instead of "field strength". The equivalent field strength is the irradiation field strength of the non-modulating signal, having the equal power with the broadband signal. 3.1.7 Minimum median equivalent field strength The minimum median field strength to ensure the receiver on the digital terrestrial television can receive the signal normally considering that the statistical factors of wanted signal field strength will vary with the time and location.3.2 Abbreviations For the purpose of this standard, the following abbreviations apply. BER Bit Error Rate C/N Carrier-noise ratio MFN Multiple Frequency Network PR Protection Ratio QAM Quadrature Amplitude Modulation SFN Single Frequency Network TS Transport Stream 4 Terrestrial Television System

Contents of GB/T 26252-2010

Foreword I 1 Scope 2 Normative References 3 Terms, Definitions and Abbreviations 4 Terrestrial Television System 4.1 Digital Terrestrial Television System 4.2 Terrestrial Analog Television System 5 Protection Ratio of Digital Terrestrial Television Signal 5.1 Protection Ratio of Digital Terrestrial Television Signal for Interference of Digital Terrestrial Television Signal 5.2 Protection Ratio of Digital Terrestrial Television Signal against Interference of Terrestrial Analog Television Signal 6 Protection Ratio of Terrestrial Analog Television Signal against Interference by Digital Terrestrial Television Signal 6.1 Protection Ratio of Picture Signal of Terrestrial Analog Television against Interference of Digital Terrestrial Television Signal 6.2 Protection Ratio of Terrestrial Analog Television Audio Signal against Interference by Digital Terrestrial Television Signal 7 Minimum Equivalent Field Strength and Minimum Median Equivalent Field Strength Received by Digital Terrestrial Television Signal 7.1 Minimum Equivalent Field Strength Received by Digital Terrestrial Television Signal at the Fixed Outdoors 7.2 Minimum Median Equivalent Field Strength Received Randomly by Digital Terrestrial Television Signal Appendix A (Normative) Calculation of Minimum Equivalent Field Strength and Minimum Median Equivalent Field Strength Appendix B (Normative) Other Planning Factors Appendix C (Normative) Comparison Method to Assess Analog Television Protection Ratio by Reference Interference Source (SCM) Appendix D (Normative) Tested Methods on Protection Ratio of Wanted Digital Terrestrial Signal Appendix E (Normative) Troposphere Interference and Continuous Interference Appendix F (Normative) Measured Power and Field Strength Conversion of Digital Television Appendix G (Normative) Combined Method on Interference Field Strength Appendix H (Informative) Channel Model Parameters Bibliography