1、 Recommendation ITU-R BT.2052-1 (10/2015) Planning criteria for terrestrial multimedia broadcasting for mobile reception using handheld receivers in VHF/UHF bands BT Series Broadcasting service (television) ii Rec. ITU-R BT.2052-1 Foreword The role of the Radiocommunication Sector is to ensure the r
2、ational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radi
3、ocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1
4、 of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent info
5、rmation database can also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (televisio
6、n) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service
7、 systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2015 ITU 2015 Al
8、l rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R BT.2052-1 1 RECOMMENDATION ITU-R BT.2052-1 Planning criteria for terrestrial multimedia broadcasting for mobile reception using handheld receivers in VHF/UHF bands
9、 (2014-2015) Scope This Recommendation defines the planning criteria for various methods of providing terrestrial multimedia broadcasting for mobile reception using handheld receivers in VHF/UHF bands. The ITU Radiocommunication Assembly, considering a) that digital multimedia broadcasting systems h
10、ave been implemented in many countries or are planned to be introduced, using the inherent capability of digital broadcasting systems; b) that many types of interference, including co-channel and adjacent channel, ignition noise, multipath and other signal distortions exist in the VHF/UHF bands; c)
11、that the error-correction, data framing, modulation and emission methods for terrestrial multimedia broadcasting systems have been defined in Recommendation ITU-R BT.2016; d) that terrestrial emission systems for mobile reception using handheld receivers require specific consideration for determinin
12、g planning criteria due to peculiar propagation characteristics; e) that the availability of consistent sets of planning criteria agreed by administrations will facilitate the introduction of terrestrial multimedia broadcasting services; f) that while there is a necessary connection between the rece
13、iver characteristics required as limit specifications for manufacturing, efficient spectrum use and frequency planning should take account of the complete receiving system and should be based on a representative reference receiving system rather than “worst-case” limit specifications, noting a) that
14、 Recommendation ITU-R BT.1368 defines the planning criteria for various methods of providing digital terrestrial television services in the VHF/UHF bands; b) that Recommendation ITU-R BS.1660 defines the planning criteria, which could be used for planning of terrestrial digital sound broadcasting in
15、 the VHF band; c) that Recommendation ITU-R BT.2033 defines the planning criteria for second generation of digital terrestrial television broadcasting systems in the VHF/UHF bands, recommends that the relevant planning criteria, including protection ratios (PRs) and the minimum field strength values
16、 given in Annexes 1, 2 and 3 should be used as the basis for frequency planning for terrestrial multimedia broadcasting services. 2 Rec. ITU-R BT.2052-1 Introduction This Recommendation contains the following Annexes: Annex 1 Planning criteria for Multimedia System A (T-DMB and AT-DMB) terrestrial m
17、ultimedia broadcasting systems in VHF/UHF bands. Annex 2 Planning criteria for Multimedia System F (ISDB-T multimedia broadcasting) terrestrial multimedia broadcasting systems in VHF/UHF bands. Annex 3 Planning criteria for Multimedia System T2 (T2 Lite profile of DVB-T2 system) terrestrial multimed
18、ia broadcasting systems in VHF/UHF bands. General The RF protection ratio is the minimum required value of the wanted-to-unwanted signal ratio, C/I, usually expressed in decibels at receiver input. For the purpose of this Recommendation, D/U will also be used in its Annexes with the identical meanin
19、g for the protection ratio. The reference level of the digital signal is defined as the r.m.s. value of the emitted signal power within the channel bandwidth. The protection ratio values for wanted digital signals were historically measured with a 60 dBm receiver input power. Where possible, protect
20、ion ratios for terrestrial multimedia broadcasting systems are derived from measurements covering a range of signal levels. Two methods of measurement can be applied: the subjective failure point (SFP) and quasi-error-free (QEF). The SFP method can be used for measurements of protection ratios. The
21、quality criterion for measurements of protection ratios is to find a limit for a just error-free picture on the TV screen. The RF protection ratio for the wanted signal is the minimum required value for the wanted-to-unwanted signal ratio at receiver input, e.g. determined with the SFP method. The S
22、FP method corresponds to the picture quality where no more than one error is visible in the picture for an average observation time of 20 s. The quality criterion for SFP corresponds to a 5% erroneous seconds ratio (ESR). The QEF method can also be used for measurements of protection ratios. The qua
23、lity criterion for protection measurements is to find a limit for the prescribed BER (e.g. 1012), which is usually applied to the evaluation of systems. 1 Reception mode Three reception modes: portable outdoor, portable indoor and mobile. The relevant administrations should consider which reception
24、modes to be included. 1.1 Portable reception In general, portable reception refers to a reception where a portable receiver is used outdoors or indoors at no less than 1.5 m above ground level. Two receiving locations will be distinguished: portable outdoor reception is defined as reception outdoors
25、 by a portable receiver with a battery supply and an attached or built-in antenna at no less than 1.5 m above ground level; portable indoor reception is defined as reception indoors by a portable receiver with an attached or a built-in antenna; Rec. ITU-R BT.2052-1 3 the receiver is used indoors at
26、no less than 1.5 m above floor level in rooms on the ground floor and with a window in an external wall. It is assumed that optimal receiving conditions will be found by moving the antenna a maximum of 0.5 m in any direction while the portable receiver and large objects in the near vicinity remain u
27、nmoved during reception. 1.2 Mobile reception Mobile reception is defined as reception by a receiver in motion at the speed of an automobile or train. Vehicle receivers may be used in addition to portable receivers. 2 Planning parameters for terrestrial multimedia broadcasting to be used for plannin
28、g study There are many planning parameters to take into account in the planning study of terrestrial multimedia broadcasting services due to a number of combinations of reception modes and other transmission systems to be considered. Planning studies should primarily be conducted using the items lis
29、ted in 2.1 and 2.2, and then other parameters listed in 3 could be applied when such parameters are thought to be included. 2.1 Basic planning parameters Two basic planning parameters are defined as below: Minimum field strength is defined as the field strength that gives the minimum input voltage o
30、f a reference receiver for correct reception, usually expressed in dBV/m. Protection ratio is the minimum value of wanted-to-unwanted signal ratio, usually expressed in decibels at the receiver input. 2.2 Reference receiving conditions The following conditions should be observed in the planning purp
31、ose: characteristics of reference receiver: To be provided in each Annex. System dependent characteristics such as C/N are included; reference antenna height: 1.5 m above ground level for portable outdoor reception, and 1.5 m above floor level in rooms on the ground floor with a window in an externa
32、l wall for portable indoor reception; reference antenna gain: 0 dBd, such as a /4 monopole antenna. 3 Other parameters to be considered in planning 3.1 Location correction factor The location correction factor is the margin to add to field strength to obtain a certain location probability. The field
33、 strength distributions of wanted and unwanted waves can be assumed to exhibit the same statistics, although they come from different directions. Recommendation ITU-R P.1546 states the standard deviation of field strengths for digital broadcasting waves is 5.5 dB and provides correction factor for d
34、ifferent location probability. 4 Rec. ITU-R BT.2052-1 Annex 1 Planning criteria for Multimedia System A (T-DMB and AT-DMB) terrestrial multimedia broadcasting systems in VHF/UHF bands This Annex describes the planning criteria for Multimedia System A in VHF band within a 6 MHz TV channel. Channel ba
35、ndwidth of Multimedia System A is 1.536 MHz. The minimum guard band between two adjacent channels is 0.192 MHz and the maximum guard band is 1.008 MHz by the channel arrangement in Korea for Multimedia System A as shown in Fig. 1. That is, the frequency spacing between the nearest two adjacent chann
36、els is 1.728 MHz apart from their central frequencies. The measurement scale of protection ratios is 1 dB. FIGURE 1 Channel arrangement of Multimedia System A in VHF band B T .2 0 5 2 -0 11 . 0 0 8 M H z6 M H z1 . 5 3 6 M H z 0 . 1 9 2 M H zThe spectrum masks operating in critical cases defined in F
37、ig. 1 of Annex 1 of Recommendation ITU-R BS.1660-6 are used for the measurement of protection ratios. AT-DMB increases channel capacity of T-DMB and guarantees backward compatibility with T-DMB. To guarantee backward compatibility with T-DMB, a hierarchical modulation mechanism is applied. Hierarchi
38、cal modulation is the technology modulating multiple data streams into one single symbol stream. AT-DMB has two layers by hierarchical modulation: the base layer and the enhancement layer. The base layer is T-DMB channel and the enhancement layer is the additional channel added by AT-DMB. AT-DMB def
39、ines two hierarchical modulation schemes: mode B using BPSK symbol mapping over DQPSK symbol and mode Q using QPSK symbol mapping over DQPSK symbol. The hierarchical modulation schemes are shown in Fig. 2. Mode B hierarchical modulation has better performance in a mobile environment. On the other ha
40、nd, mode Q hierarchical modulation is more advantageous in a fixed reception environment. AT-DMB also defines a constellation ratio. The constellation ratio is defined as: ba where: a: maximum distance between two neighbouring quadrants b: maximum distance between constellation points in a quadrant.
41、 AT-DMB supports four constellation ratios: 1.5, 2.0, 2.5 and 3.0. By changing the value of the constellation ratio, the performance of the base layer and the enhancement layer of AT-DMB would be changed. AT-DMB adopted Turbo code in the enhancement layer in order to improve its reception performanc
42、e, whereas Convolutional code is used in the base layer. AT-DMB supports four Turbo code rates: 1/2, 2/5, 1/3, 1/4. The performance of the enhancement layer of AT-DMB would be increased as the value of Turbo code rate decreases. Rec. ITU-R BT.2052-1 5 Refer to Report ITU-R BT.2049-5, Recommendation
43、ITU-R BT.1833-2 and Recommendation ITU-R BT.2016 for more information. FIGURE 2 AT-DMB hierarchical modulation scheme B T . 2 0 5 2 - 0 2ReImCo ns t e l l a t i on po i nt (e ve n s ym bo l )Co ns t e l l a t i on po i nt (od d s ym bo l )babaMo d e B h i erarc h i cal mo d u l at i o nbabaMo d e Q
44、h i erarc h i cal mo d u l at i o nReImCo ns t e l l a t i on po i nt (e ve n s ym bo l )Co ns t e l l a t i on po i nt (od d s ym bo l )The effective data rates of T-DMB/AT-DMB depend on its forward error correction (FEC) code rates as shown in Table 1. Since Turbo code rate of AT-DMB enhancement l
45、ayer can be selected regardless of Convolutional code rate of T-DMB/AT-DMB base layer, the total effective data rate of AT-DMB is to add effective data rates of AT-DMB base layer and AT-DMB enhancement layer. TABLE 1 Effective data rates of T-DMB/AT-DMB T-DMB/AT-DMB base layer AT-DMB enhancement lay
46、er (Mode B) FEC code rate Convolutional code 1/2 Turbo code 1/2 Turbo code 2/5 Turbo code 1/3 Turbo code 1/4 Effective data rate 1.152 Mbit/s 0.576 Mbit/s 0.448 Mbit/s 0.384 Mbit/s 0.288 Mbit/s The Convolutional code rate 1/2 at T-DMB and at the base layer of AT-DMB is usually used. Mode B at AT-DMB
47、 is used for the mobile broadcasting service. Protection ratios would be different whether its test signal is video or audio. It is because BER for correcting errors of test signal at the receiver side is different from each other. To measure precise protection ratios, the spectrum mask shall be app
48、lied each to the outputs of both wanted and unwanted T-DMB/AT-DMB signals. But whether the spectrum mask is applied to the output of T-DMB/AT-DMB wanted signal or not, the performance of its reception is the same. Taking these into consideration, the spectrum mask was applied to the output of unwant
49、ed T-DMB/AT-DMB signal and not applied to the output of T-DMB/AT-DMB wanted signal. Thus, a protection ratio test had been measured under the following conditions: convolutional code rates of T-DMB and the base layer of AT-DMB are set to 1/2; 6 Rec. ITU-R BT.2052-1 hierarchical modulation mode of AT-DMB is set to mode B; QVGA quality videos are only used for test; frequency of unwanted T-DMB/AT-DMB signal is set to 213.008 MHz; constellation ratio of unwanted AT-DMB signal is set to 2.0; turbo code rate of unwanted AT-DMB signal is set to 1/2; spe
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1