CN1678068A - Single-frequency network system of ground digital TV broadcast and its realizing method - Google Patents

Single-frequency network system of ground digital TV broadcast and its realizing method Download PDF

Info

Publication number
CN1678068A
CN1678068A CNA2004100034926A CN200410003492A CN1678068A CN 1678068 A CN1678068 A CN 1678068A CN A2004100034926 A CNA2004100034926 A CN A2004100034926A CN 200410003492 A CN200410003492 A CN 200410003492A CN 1678068 A CN1678068 A CN 1678068A
Authority
CN
China
Prior art keywords
output
signal
packet
circuit
input
Prior art date
Application number
CNA2004100034926A
Other languages
Chinese (zh)
Other versions
CN1312929C (en
Inventor
杨知行
王劲涛
房海东
潘长勇
王军
韩猛
Original Assignee
清华大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 清华大学 filed Critical 清华大学
Priority to CNB2004100034926A priority Critical patent/CN1312929C/en
Publication of CN1678068A publication Critical patent/CN1678068A/en
Application granted granted Critical
Publication of CN1312929C publication Critical patent/CN1312929C/en

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/20Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
    • H04N21/23Processing of content or additional data; Elementary server operations; Server middleware
    • H04N21/242Synchronization processes, e.g. processing of PCR [Program Clock References]
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/20Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
    • H04N21/23Processing of content or additional data; Elementary server operations; Server middleware
    • H04N21/238Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams
    • H04N21/2383Channel coding or modulation of digital bit-stream, e.g. QPSK modulation

Abstract

The system comprises three parts: adapter in single frequency network, GPS receiver, and modulator of supporting ground digital TV broadcasting in single frequency network. At central transmitting terminal, the adapter inserts MIP packets in transmission code stream. MIP packet carries synchronizing time label relevant to GPS receiver and system maximal time delay to each relay station etc. In each relay station, synchronization system detects M1P packets, reading out time label and maximal time delay, measuring time delay of received signal, calculating out additional time delay. According to the additional time delay, TS flow is delayed properly in order to make signal synchronization again among relay stations. The disclosed scheme is realized through FPGA, and is applied to ground digital multiple media broadcasting transmission system forwaded by Tsinghua Univ. Favorable effect is obtained through actual try.

Description

地面数字电视广播的单频网系统及其实现方法 SFN digital terrestrial television broadcasting and its implementation

技术领域 FIELD

本发明属于数字信息传输技术领域,特别涉及一种地面数字电视广播(Digital TV terrestrialbroadcasting,DTTB)的单频网(Single FrequnecyNetwork,SFN)系统。 The present invention belongs to the technical field of digital transmission of information, particularly, to a digital terrestrial television broadcast (Digital TV terrestrialbroadcasting, DTTB) SFN (Single FrequnecyNetwork, SFN) system.

背景技术 Background technique

在传统的模拟电视广播中,为了对一定区域进行覆盖,相邻发射台需使用不同的频率以避免相互干扰,同一频率必须在一定距离以外才能进行重用,此即多频网(Multi-Frequnecy Network,MFN)方式,如图1所示。 In the conventional analog television broadcasting, in order to cover a certain area, the neighboring transmitting stations need to use different frequencies in order to avoid mutual interference, the same frequency can be reused from a distance, namely multi-frequency network (Multi-Frequnecy Network , MFN) mode, as shown in FIG. 在多频网方式下,为可靠覆盖一个区域必须使用多个差转台,由于频率复用的原因,覆盖一个区域需要占用多个频率。 In the multi-frequency network mode, a reliable coverage area of ​​the turntable must use a plurality of difference, due to the frequency multiplexing, cover an area needs to occupy a plurality of frequencies. 这样,一路信号需要占用几倍的带宽,消耗了大量的频谱资源。 In this way, one signal needs to occupy several times the bandwidth consumed a lot of spectrum resources.

随着电视广播技术的的飞速发展,电视现在已经进入了一个新时代:数字电视时代。 With the rapid development of television technology, television has now entered a new era: the era of digital television. 数字电视是指全部采用数字方式制作、传输和接收电视节目,能使观看者收看到相当于电视台演播室节目质量的图象、声音,没有重影和“雪花”。 It refers to all digital television digitally production, transmission and reception of television programs, the viewer can watch the television studio programs corresponding to the image quality, sound, and no ghosting "snow." 它是集数字信号及信息处理技术、数字通信技术、计算机及网络技术、微电子技术等高新技术发展于一体的高科技产物。 It is a digital signal and information processing technology, digital communications technology, computer and network technology, microelectronics and other high-tech development of high-tech products. 数字电视广播主要通过卫星、有线电视及地面无线三种传输方式实现。 Digital TV broadcasting mainly through satellite, cable and terrestrial wireless three transmission modes. 一般认为,卫星广播着重于解决大面积覆盖。 Generally it believed that satellite radio focused on solving large area coverage. 有线电视广播着重于解决“信息到户”,特别是在城镇等人口居住稠密地区。 Cable television broadcast focused on solving the "information home", especially in the towns and other population live in densely populated areas. 而地面无线广播作为电视广播的传统手段,由于其所独具的简单接收和移动接收的能力,能够满足现代信息化社会所要求的“信息到人”的基本需求。 The terrestrial radio as a traditional means of television broadcasting, due to the simplicity and the ability to receive mobile reception of its unique, to meet the basic needs of a modern information society required "message to the people". 所以,地面数字电视广播在未来数十年中将具备极大的商业价值。 Therefore, the terrestrial digital TV broadcasting has great commercial value in the coming decades. 随着频率资源的日趋紧张,在数字电视地面广播中引入了单频网的概念。 With the increasingly tight frequency resources, it introduces the concept of a single frequency network in the digital television terrestrial broadcasting. 所谓单频网(SFN)是指若干个发射台同一时间在同一个频率上发射同样的信号,以实现对一定服务区域的可靠覆盖。 The so-called Single Frequency Network (SFN) refers to the number of transmitting stations transmit the same signal at the same time on the same frequency, in order to achieve a reliable coverage of a certain service area. 一种单频网覆盖示意图如图2所示。 A schematic view of a single-frequency network coverage shown in FIG. 采用单频网进行电视广播,是电视技术数字化带来的结果,多载波数字调制和数字信号处理技术,使单频网的应用成为可能。 Single frequency network for television broadcasting, television technology is the result of digitization, the digital multi-carrier modulation and digital signal processing technology, the SFN application becomes possible.

单频网带来的最直接的一个好处是频谱效率的提高。 SFN bring the most immediate benefit is to improve spectral efficiency. 相对于传统的多频网而言,由于不需要频率重用,在服务区域内传送一路信号只需要一个频段,因此节省了大量的频率资源,对于需要较大带宽的电视广播而言,这一优点更为突出。 With respect to the conventional multi-frequency network, the frequency reuse is not required, transmits one signal within the service area needs only one frequency band, thus saving a lot of frequency resources, for television broadcast purposes requires a large bandwidth, the advantage more prominent. 多个发射台同时工作所带来的分集效果,也使得接收的可靠性得到增强,获得更好的节目覆盖率。 A plurality of transmitting stations simultaneously brought diversity effect, but also makes the received enhanced reliability, better coverage of the program. 此外,通过对发射网络(如发射机的数量、分布、单个发射机的高度、发射功率等)的调整和优化,还可降低总的功耗,减轻对附近其它网络的干扰,甚至根据需要方便灵活的改变覆盖区域的分布。 Further, by adjusting and optimizing the transmit network (such as the number of transmitters, the distribution, the height of a single transmitter, transmit power, etc.), but also reduce the total power consumption, reduce interference with other nearby networks, or even necessary, to facilitate changes in the distribution area of ​​the flexible cover.

单频网的提出是与多载波调制方式紧密相联的,比如正交频分复用(OrthogonalFrequency Division Multiplexing,OFDM)。 SFN is proposed with a multi-carrier modulation closely related, such as orthogonal frequency-division multiplexing (OrthogonalFrequency Division Multiplexing, OFDM). OFDM调制方式的一个特点是符号带有保护间隔(Guard Interval),落在保护间隔内的多径信号,在经过均衡以后,非但不会产生前后符号间的干扰(ISI),甚至加强了有效信号的功率。 A feature of OFDM modulation is a symbol with a guard interval (Guard Interval), multipath signals fall within the guard interval, after equalized, not only does not produce interference (ISI) between the preceding and following symbols, and even enhanced the effective signal power. 在一个多径情况严重的无线环境,除了反射、散射等造成的自然多径以外,其它发射机在同一频率上所发射的信号也产生大量人工多径,而且可能是强多径。 In one case of severe multipath radio environment, in addition to natural multipath reflections, scattering caused by signals of other transmitters on the same frequency transmitted also generates a lot of artificial multipath, and may be strong multipath. 依靠OFDM调制,可以较容易地处理这些复杂的多径,使单频网的应用成为可能。 Rely on OFDM modulation, it is easier to handle these complex multi-path, so that the application SFN possible.

数字电视地面广播(DTTB)目前在国际上主要有三个标准,即美国高级电视系统委员会(Advanced Television Systems Committee,ATSC)研发的格形编码的八电平残留边带(Trellis-Coded 8-Level Vestigial Side-Band,8-VSB)调制系统;欧洲数字视频地面广播(Digital Video Terrestrial Broadcasting-Terrestrial,DVB-T)标准采用的编码正交频分复用(Coded Orthogonal Frequency Division Multiplexing,COFDM)调制;日本地面综合业务数字广播(Integrated Service Digital Broadcasting-Terrestrial,ISDB-T)采用的频带分段传输(Bandwidth Segmented Transmission,BST)正交频分复用。 Digital Terrestrial Television Broadcasting (DTTB) At present, there are three standards in the international arena, namely the United States Advanced Television Systems Committee (Advanced Television Systems Committee, ATSC) developed by trellis coded eight-level vestigial sideband (Trellis-Coded 8-Level Vestigial Side-Band, 8-VSB) modulation system; European digital video broadcast-terrestrial (digital video terrestrial broadcasting-terrestrial, coded orthogonal DVB-T) standard uses a frequency division multiplexing (coded orthogonal frequency division multiplexing, COFDM) modulation; Japan terrestrial integrated services digital broadcasting (integrated service digital broadcasting-terrestrial, ISDB-T) transmission frequency band segment (Bandwidth segmented transmission, BST) uses orthogonal frequency-division multiplexing. 这三种标准最主要的区别在于调制方式,其中欧洲标准和日本标准都采用了基于OFDM的多载波调制技术,而美国标准则使用了8-VSB的单载波调制方式。 Three standard main difference is that the modulation scheme, wherein both European and Japanese standard using OFDM based multi-carrier modulation technique, and the US standard using single carrier modulation scheme is 8-VSB. 调制方式的差别直接影响了单频网在不同标准中的应用。 Differential modulation scheme directly affects the application of a single frequency network in a different standard. 采用多载波技术的欧洲标准和日本标准对于单频网具有天然的良好支持能力。 Multi-carrier technology for European and Japanese standards SFN has a natural good support. 一般而言,美国ATSC的标准不支持同步的单频网。 In general, the American ATSC standard does not support synchronization of SFN. 由于采用的是单载波调制技术,处理多径的能力主要来自于自适应均衡器,在有多个发射台同时发射信号的强多径环境中,实现单载波的单频网相当困难。 As a result of the single-carrier modulation techniques, the multipath mainly from the ability of the adaptive equalizer, in a strong multipath environment with a plurality of transmitting stations simultaneously transmit signals, quite difficult to achieve single-SFN carrier. 在ATSC标准下,除了使用多频网方案以外,还采用同信道再生器(On-channel repeater)的方式来扩展服务区域。 In the ATSC standard, except that multi-frequency network scheme, it also uses the same channel regenerator (On-channel repeater) way to extend the service area. 再生器接收发射台的信号,进行简单的处理后将信号转发出去。 Regenerator receiver signal transmitting station are forwarded out signal after a simple process. 为了减少人为的多径干扰,再生器和接收器往往使用定向天线。 In order to reduce man-made multipath interference, and receiver regenerator tend to use directional antennas. 由于不同的再生器发射信号是不同步的,因此严格地说,这种结构不是单频网。 Due to the different regenerator transmitted signal are not synchronized, so strictly speaking, this structure is not a single frequency network. 当然,同信道再生器在采用多载波调制方式的方案中也可用作扩展服务区域。 Of course, the same channel regenerator multi-carrier modulation scheme may be used as an extended service area. 另外,使用定向天线也同样有助于单频网的实现。 Further, the use of directional antennas also contribute to the Single Frequency Network.

单频网中最关键的技术要求就是各个发射机所广播的信号在频率和时间上都实现同步。 SFN is the most important technical requirements individual transmitters broadcast signals in both frequency and time synchronization. 频率同步要求每个单频网发射机的工作频率都彼此相同,对于多载波调制而言,还要求每个子载波的绝对频率相等。 Each frequency synchronization required operating frequency of the single frequency network transmitters are identical to each other, to multicarrier modulation, also requires the absolute frequency of each subcarrier are equal. 频率同步可利用一个共同的参考频率(例如,来自GPS卫星的参考频率)控制所有的调制器来实现。 Frequency synchronization can utilize a common frequency reference (e.g., reference frequency from a GPS satellite) control all the modulators to achieve.

OFDM中保护间隔的长度决定了系统所能处理的多径信号的最大延迟时间,从而限制了单频网发射机之间的最大距离。 OFDM guard interval length determines the maximum multipath signal delay time of the system can handle, thus limiting the maximum distance between the SFN transmitters. 保护间隔越长,发射机间的距离就可以越大,在DVB-T和ISDB-T标准中,都提供了保护间隔比较大的8k工作模式以实现大尺度的单频网,覆盖一个国家或者一个地区。 The longer the guard interval, the distance between the transmitter will be greater, the DVB-T and ISDB-T standard, provides a relatively large guard interval 8k operating mode to achieve a large-scale SFN covering a nation or a region. 较小保护间隔的模式则用以提供本地单频网覆盖。 The smaller the guard interval mode is used to provide local SFN coverage. 在DVB标准中,不同保护间隔下的最大延时扩展与发射机间距离之间的关系见图3。 In the DVB standard, the maximum delay spread between the transmitter at different guard interval relationship between the distance shown in Figure 3.

另一方面,保护间隔越长,系统的传输效率就越低,而超出保护间隔的多径信号对于接收机而言是干扰,将影响系统性能。 On the other hand, the longer the guard interval, the lower the transmission efficiency of the system, the multipath signal exceeds the guard interval for the receiver is an interference will affect the system performance. 因此要求发射机在相同的时间发射完全相同的OFDM符号,实现时间同步,从而让有限的保护间隔在处理多径上发挥作用,而不是消耗在补偿发射机之间的同步误差上。 Thus requiring the transmitter to transmit at the same time identical OFDM symbols, time synchronization, a guard interval so that the limited play a role in the multipath, and not consumed by the synchronization error between the compensated transmitter.

在单频网的实际应用中,还有一类称为“补点器”的发射台,它们主要分布在由于距离远或衰减严重而无法接收信号的较小区域,对这些区域进行“弥补”。 In practical applications in single frequency network, there is a class called emitter station "fill point" on, which are mainly in the small area unable to receive the signal attenuation due to distance or severe, of these areas is "make up." 出于经济因素的考虑,这些补点器在同步的要求上相比一般的发射机不是那么严格,因此在发射功率上也往往比一般的单频网发射机低得多。 For economic reasons, which make up points in the synchronized transmitter compared to the general requirement is not so stringent, and therefore tend to be much lower than the average in the transmission power of SFN transmitters.

目前,采用DVB-T标准的国家和地区有欧洲各国、澳大利亚、新加坡等。 Currently, the use of DVB-T standard in countries and regions are Europe, Australia and Singapore. 美国、加拿大、韩国等国家采用了ATSC标准。 United States, Canada, South Korea and other countries have adopted the ATSC standard. 日本则采用了自己提出的ISDB-T标准。 Japan is using its own proposed ISDB-T standard. 在经过一段时间的准备、试验和调整后,各国分别在部分地区,主要是大城市及其周边地区进行了数字电视地面广播。 After preparation, testing and adjustment period, countries are in some areas, mainly in large cities and their surrounding areas were digital terrestrial television broadcasting. 其中使用了单频网的基本是基于DVB-T标准。 Wherein the single frequency network is substantially based on the DVB-T standard.

我国自1994年起,也开始了高清晰度电视的研究工作。 China since 1994, began the research work of high-definition television. 并于1998年研制成功了中国第一代高清晰度电视功能样机。 And in 1998 successfully developed China's first generation of HDTV functional prototype. 由广播电视主管单位、国家广电总局组织了我国的专家对数字电视及数字高清晰度电视标准进行了制定,清华大学提出的地面数字多媒体广播传输协议是测试方案之一。 By the Radio and Television unit in charge of China's State Administration of Radio Organization expert on digital TV and digital HDTV standards were developed, terrestrial digital multimedia broadcasting transmission protocol Tsinghua University is one of the proposed test program. 此方案采用时域同步的TDS-OFDM技术。 This embodiment of the time-domain synchronous TDS-OFDM technology. TDS-OFDM属于多载波调制技术,它利用了扩频通信技术,插入了PN序列在时域进行帧同步、频率同步、定时同步、信道传输特性估计和跟踪相位噪声等。 TDS-OFDM is a multi-carrier modulation technique which uses spread spectrum communication technology, the PN sequence inserted in the time domain frame synchronization, frequency synchronization, timing synchronization, channel estimation and tracking of the transmission characteristics of phase noise. 由于使用了扩频码,使得TDS-OFDM系统具有了扩频通信的优越性能,从而使得系统既具有COFDM的优点,又回避了其缺点。 Since a spread code, so that a TDS-OFDM system with superior performance spread spectrum communication, so that the system has the advantages of both COFDM, but also avoids the disadvantages.

TDS-OFDM传输系统采用了分级帧结构,见图4。 TDS-OFDM transmission system uses a hierarchical frame structure shown in Figure 4. 它具有周期性,并且可以和绝对时间同步。 It has periodicity, and can be an absolute time synchronization. 帧结构的基本单元称为信号帧,如图5所示。 The basic unit is called a frame configuration signal frame shown in FIG. 一个信号帧包含一个数据帧加一个保护间隔,保护间隔的长度可以为数据帧长的1/9或者1/4。 A signal frame comprising a data frame plus a guard interval, the data length of the guard may be 1/9 or 1/4 of the frame length interval. 一个信号帧群根据保护间隔的长度不同,帧群是包含M(M为整数)个如图5结构所示的信号帧构成。 A signal frame group depending on the guard interval length, comprising a frame group is M (M is an integer) as shown in FIG. 5 texture signal frames. 一个大帧(Megaframe)包含4个帧群,在每一个大帧中包含N(N为整数)个188字节的MPEG-2(Moving Picture Experts Group phase 2)的TS包,TS包结构如图6所示。 A large frame (Megaframe) groups comprising four frames, each comprising a large N frames (N is an integer) of 188 bytes MPEG-2 (Moving Picture Experts Group phase 2) of the TS packet, TS packet structure is shown in FIG 6. 一个超帧包含480个帧群(或者120大帧)。 Superframe 480 comprises a frame group (or a large frame 120).

由于系统采用OFDM调制以及信号帧与绝对时间同步这两个特点,因此在实现单频网上具有先天的优势。 Because the system uses OFDM modulation signal and the absolute time frame synchronization these two characteristics, it has inherent advantages in achieving single frequency network. 本发明就基于这种帧结构提出了一种简单可靠的单频网实现方法。 The present invention is to propose a simple and reliable method to achieve single-frequency network based on such a frame structure.

发明内容 SUMMARY

本发明的目的在于提出一种地面数字电视广播的单频网系统及其实现方法。 Object of the present invention is to provide a digital terrestrial television broadcasting SFN and implementation method.

本发明提出的低复杂度、可靠的单频网(SFN)系统主要由单频网适配器、全球定位系统(Global Position System,GPS)接收机、支持单频网的地面数字电视广播调制器三部分组成。 Proposed low complexity of the present invention, a reliable single frequency network (SFN) system consists of a single frequency network adapter, three parts of a global positioning system (Global Position System, GPS) receiver, a terrestrial digital television broadcasting to support SFN modulator composition. 在中心发射端,SFN适配器在MPEG-2的传输流(Transport Stream,TS)中插入MIP(Megaframe Initialization Packet)包,MIP包中携带与GPS接收机相关的同步时间标签(Synchronization Time Stamp,STS)和到各个中继站的系统最大延时(Max Delay,MD)等信息。 The central transmitter, SFN adapter into the MIP (Transport Stream, TS) in the MPEG-2 transport stream (Megaframe Initialization Packet) packets, MIP packet carries a timestamp associated with the synchronization of the GPS receiver (Synchronization Time Stamp, STS) maximum system delay and the respective relay station (Max delay, MD) and other information. 在各个中继站,同步系统检测MIP包,从中读出时间标签和最大延时,测量接收信号延时(Measured Delay),计算出附加延时(Additional Delay),并按照附加延时适当延迟TS流,使得各个中继站再次发射的信号同步。 In various relay stations, the system detects MIP synchronization packets, read from the tag and the maximum delay time, measures received signal delay (Measured Delay), an additional delay is calculated (Additional Delay), and the additional delay in accordance with the stream suitable delay the TS, so that each relay station transmits a signal synchronized again.

本发明提出的地面数字电视广播的单频网系统的基本结构框图如图7所示。 The basic structure of SFN system proposed by the invention terrestrial digital television broadcast block diagram shown in Fig. SFN适配器的输出是一个合法的MPEG-2传输流,输出的TS包按照一定数量N组成一组,称为一个大帧(Megaframe)。 SFN adapter output is a valid TS MPEG-2 transport stream packets according to the output of a number N form a group, called a large frame (Megaframe). N为一整数,其大小可以视TS码流的传输速率而调整。 N is an integer, the size of which depends on the transmission rate may be the adjusted TS stream. 在中心发射站,用一个SFN适配器每隔一个大帧在MPEG-2传输流中插入一个MIP包,MIP包中携带同步时间标签(STS)和到各个中继站的系统最大延时。 In the central transmitting station, with a large frame every SFN adapter is inserted in a MIP packet MPEG-2 transport stream, MIP packet carries a synchronization time stamp (STS) to the system and the maximum delay of each relay station. STS是GPS接收机的1pps(one pulse per second)信号到大帧开始的时间差,如图8所示。 STS is a GPS receiver 1pps (one pulse per second) signal to the large time difference between the start frame, as shown in FIG.

MIP的结构和MPEG-2的TS流的帧结构完全一致,它包括4字节的包头和184字节的有效载荷,具体组成见图9。 MIP structure and the frame structure of the TS MPEG-2 stream is exactly the same, which comprises a 4-byte payload header of 184 bytes, the specific composition shown in Figure 9. 各部分的解释如下:包头(transport packet heater):符合ISO/IEC 13818-1中有关TS流包头的定义; Explanation of each part as follows: header (transport packet heater): compliance with ISO / IEC 13818-1 in the definition of TS stream header;

同步指示(synchronizatio_id):用于识别所用的同步配置,即是否采用单频网同步配置;块长度(section_length):用于指示紧随其后的这一包中的字节数,包含至CRC_32校验的最后一位,不包含填充字节;指针域(pointer):用2字节的二进制整数指示随后的Megaframe的第一包距离此MIP的TS流包数。 Synchronization instruction (synchronizatio_id): used for identifying a synchronization profile, i.e., whether single frequency network synchronization configuration; block length (section_length): is used to indicate the number of bytes immediately subsequent to this package, comprising correction to CRC_32 the last test, does not include stuffing bytes; pointer field (pointer): with 2-byte binary integer indicating the number of TS packets from this stream MIP Megaframe subsequent first pack. 指针的范围由地面数字电视广播所用的调制模式而定;时间同步标签(synchronization_time_stamp):第M个Megaframe中的MIP的时间同步标签用于指示第M+1个Megaframe的实际起始时间(从开始传送第一包第一字节开始)与最近的脉冲参考(pps,由GPS得到)之间的差值;最大延时(maximum_delay):第M个Megaframe中的MIP的最大延时用于指示从发射天线发出的数字基带信号中的第M+1个Megaframe的开始和SFN适配器中的第M+1个Megaframe的开始的差值。 Range determined by the pointer terrestrial digital broadcasting modulation mode used; time synchronization tag (synchronization_time_stamp): MIP M-th time synchronization Megaframe first label for indicating the M + 1 Megaframe actual start time (from start transmitting a first packet of the first byte) and the nearest reference pulses (pps, obtained by the difference between the GPS); the maximum delay (maximum_delay): M-th maximum delay of MIP Megaframe for indicating from the first difference between the first M + 1 M + 1 Megaframe Megaframe starting SFN adapter and the start of the digital baseband signal sent by the transmitting antenna. 最大延时的数值应大于主要分布式网络中的最长延时与调制器延时、中继器延时、天线馈线延时的总和。 Value should be greater than the maximum delay time delayed by the modulator mainly distributed network delay, repeater delay, the total delay antenna feed. 最大处理的延时是1秒;CRC校验(CRC 32):共32比特,计算时不包含填充字节;填充字节(stuffing_yte):每个填充字节的值为0xFF。 The maximum processing delay time is 1 second; the CRC check (CRC 32): a total of 32 bits, the calculation does not include stuffing bytes; stuffing bytes (stuffing_yte): filling each byte of 0xFF.

MIP的所有参数(例如STS和MD)均对应于相邻的下一个Megaframe,即指针域中的指针所指向的Megaframe。 All MIP parameters (e.g. STS and MD) each corresponding to a next adjacent Megaframe, i.e. the pointer to point to the domain Megaframe. 例如,第M个Megaframe中的MIP参数值对应于第M+1个Megaframe。 For example, MIP M-th parameter value corresponding to the Megaframe of the M + 1 Megaframe.

在每一个接收点,当检测到MIP时,地面数字电视广播调制器中的同步系统就会测出本地相应的大帧的开始时间与从GPS接收机得到的1pps信号的时间差(Measured Delay),如图10所示。 At each receiving point, when detecting the MIP, terrestrial digital television broadcasting system modulator will detect synchronization start time of the corresponding frame is large 1pps local time signal obtained from the differential GPS receiver (Measured Delay), as shown in FIG. 同时从收到的MIP中得到STS时间标签和信道的最大延时MD信息,然后由下式可计算得到传输码流应加的附加延时(Additional Delay):STS+MD=Measured Delay+Additional Delay每个地面数字电视广播调制器根据计算得到的附加延时就可以将经过不同网络路径传播的传输码流延时对齐,以保证单频网应用中的时间同步要求。 Meanwhile STS time stamp obtained from the channel and MIP maximum delay MD received information, and then calculated by the following formula obtained transport stream should be added to the additional delay (Additional Delay): STS + MD = Measured Delay + Additional Delay each modulator terrestrial digital television broadcasting can be transmitted through different streams in the network propagation delay alignment in accordance with the calculated additional delay to ensure that the SFN time synchronization application requirements.

同步系统还可以给出一个复位信号(Reset),使得各个中继站的调制器能够在同一时刻复位。 The system can also give a synchronization reset signal (Reset), such that the modulator of each relay station can be reset at the same time. 复位信号信息是由MIP包携带的,中心发射站给出复位信号,各个中继站同时复位各个调制器,使得每个调制器的信号帧保持绝对同步。 MIP reset signal information is carried in the packet, the central station transmitting a reset signal is given, the relay stations simultaneously resetting respective modulators, each modulator such that signal frame absolute synchronization is maintained.

本发明提出的地面数字电视广播的单频网系统,含有单频网适配器、GPS接收机、分布式网络和同步系统等,其特征在于,它含有:(1)MPEG-2复用器,包括:带有视频信号输入端的视频子系统,带有音频信号输入端的音频子系统,复用器,它由单节目复用电路和多节目复用电路串接而成,单节目复用电路的两个输入端分别与视频子系统、音频子系统的基本业务流输出端相连,多节目复用电路的几个输入端分别依次与单节目复用电路的几个传送流输出端相连;(2)单频网适配器即SFN适配器,它含有:(2.1)接口格式变换电路,包括:同步并行接口即SPI转换到异步串行接口即ASI的芯片,异步串行接口转换到同步并行接口的芯片;根据要求的传输流即TS流的接口格式,在信号输入时,ASI到SPI接口格式变换电路的输入端与MPEG-2复用器中多节目复用电路的TS流输出端相 The present invention is proposed digital terrestrial television broadcasting SFN system, comprising SFN adapter, GPS receivers, distributed network synchronization system and the like, characterized in that it comprises: (1) MPEG-2 multiplexer, comprising : video subsystem having a video signal input terminal, an audio subsystem having an audio signal input terminal, a multiplexer, a single program which series circuit and the multiplexing circuit from the multi-program multiplexing, the single program of two multiplexing circuit inputs video subsystem, respectively, a basic service stream output audio subsystem is connected to the multi-program multiplexing and sequentially, a single program multiplexing several inputs connected to the circuit with a few transport stream output circuit; (2) SFN adapter i.e. SFN adapter, comprising: (2.1) interface format conversion circuit, comprising: a synchronous parallel interface SPI i.e. converted into asynchronous serial interface chip ASI i.e., asynchronous serial interface conversion to synchronous parallel interface chip; according TS stream output terminal requested transport stream TS stream interface format i.e., when the signal input, the ASI to SPI interface format conversion circuit input terminal and the MPEG-2 multiple program multiplexing multiplexer circuit ;(2.2)空包滤除电路,在数字电路中实现,包括:三个依次串接的移位寄存器,其中第一个移位寄存器的输入端与接口格式变换电路的TS流输出端相连;空包判断电路,它的三个输入端依次分别与第一、第二、第三个移位寄存器的TS流输入端相连;(2.3)缓存器,在数字电路中实现,它是一个FIFO存储器,它的输入端与空包虑除电路的经空包滤除后的TS流输出端相连;(2.4)大帧初始化包即MIP包的形成电路,在数字电路中实现,其中,MIP包的结构和MPEG-2的TS流的帧结构完全一致,它包括4字节的包头和184字节的有效载荷,具体由以下各部分组成,它们是对各个大帧初始化包都相同且对应的:a)包头,b)同步指示,c)块长度,排除填充字节, ; (2.2) null packet was filtered off circuit, in digital circuits, comprising: three shift registers sequentially connected, wherein a first TS input shift register interface format converting circuit connected to an output terminal of the stream; null packets determination circuit, which in turn is connected to the three input terminals of the first, second, third TS stream input shift register, respectively; (2.3) buffer, implemented in digital circuitry, which is a FIFO memory , its other input terminal of the TS stream output by filtering out the empty bag is connected to the circuit considered null packets; forming circuit (2.4) large frame initialization packet i.e. MIP packet, implemented in digital circuitry, wherein, MIP packet the structure and the MPEG-2 TS stream identical frame structure, which comprises a 4-byte payload header of 184 bytes, the specific composition of the following parts, which are the same for each large frame initialization packet and corresponding to: a) header, b) indicates synchronization, c) the block length, stuffing bytes excluded,

d)指针域,它是一个2字节的二进制整数,它表示随后大帧的第一包距离此MIP包的TS流包数,e)同步时间标签即STS,第M个大帧中的MIP包的同步时间标签表示第M+1个大帧的实际起始时间与最近的由发射端GPS得到的参考脉冲即1pps之间的差值,f)最大延迟即MD,它表示从发射天线发出的数字基带信号中的第M+1个大帧开始时间和单频网适配器中的第M+1个大帧的开始时间的差值,最大处理的延时是1秒,g)CRC校验,共32比特,h)填充字节;(2.5)发送端的GPS接收机,它通过RS232接口与MIP包形成电路互连,它的10M信号和参考脉冲即1pps的输出端与MIP包形成电路的相应输入端相连;(2.6)复用及速率适配电路,在数字电路中实现,它含有:复用及速率适配子电路,它在数字电路中实现,它有四个信号输入端:MIP包指示有效信号、MIP包、缓存器空指示信号和滤除空包后的TS流信号 d) pointer field, which is a 2-byte binary integer which represents the number of TS packets and then a first stream packet from this frame MIP large package, e) the STS synchronous time stamp i.e., the M-th frame MIP large synchronization time stamp packet M + represents an actual start time of a frame reference pulse that is a large difference between the 1pps, f) i.e. the maximum delay MD and the nearest end GPS obtained by emission, which represents the transmit antenna from M + 1 large first frame start time and a single digital baseband signal in a first frequency network adapter M + difference between start time of a frame is large, the maximum processing delay time is 1 second, g) CRC check , a total of 32 bits, h) stuffing bytes; (2.5) transmits GPS receiver end, which forms the circuit interconnects MIP packet via the RS232 interface, it 10M and a reference pulse signal that is the output of 1pps MIP packet forming circuits is connected to a respective input terminal; (2.6) multiplexing and rate adaptation circuit, a digital circuit, comprising: multiplexing and rate adaptation sub-circuit, it is implemented in a digital circuit, which has four signal inputs: the MIP packet indicates a valid signal, MIP packet, TS stream signal indicative of the buffer empty signal and the filtered air bag 它的输出信号有三种情况:MIP包指示信号有效时,优先传输MIP包;MIP包指示信号无效且缓存器不空时,传输TS流;MIP包指示信号无效且缓存器为空时,传输空包;节目时钟参考即PCR校正电路,它的输入端与复用及速率适配子电路的输出端相连;(3)发送端的传输网络适配器,它的输入端与单频网适配器的符合MPEG-2标准的TS流输出端相连,它是市售产品;(4)分布式网络,它的输入端与传输网络适配器的网络传输信号输出端相连;(5)接收端的多个传输网络适配器,它们的每一个输入都是网络传输信号;(6)接收端的多个GPS接收机,它们的每一个的10MHz信号和参考脉冲即1pps的输出端与同步系统中的MIP检测电路的相应输入端相连,每一个的10MHz信号输出端还与同步系统中的锁相环的相应输入端相连; Its output signal has three cases: MIP packet indication signal is active, the priority transmission MIP packet; invalid MIP packet indicating signal and the buffer is not empty, the transmission TS stream; MIP packet indication signal is inactive and the buffer is empty, the transmission space packet; i.e. the program clock reference PCR correction circuit, coupled to its input terminal and an output terminal multiplexed rate adaptation subcircuit; (3) transport network adapter transmitting end, its input terminal SFN adapter conforms MPEG- standard 2 TS stream output is connected, which is a commercially available product; (4) a distributed network, network transmission signal output terminal is connected to its input terminal and the transmission network adapter; (5) a plurality of network adapters transmission receiving end, which each network transmission signal is input; connected to the output (6) a plurality of GPS receivers receiving end, their 10MHz reference signal and each pulse of the synchronization system 1pps i.e. the MIP respective input terminals of the detection circuit, 10MHz signal output of each further connected to a respective input of the phase locked loop synchronous system;

(7)接收端的多个同步系统,它们的输入端分别与各传输网络适配器的符合MPEG-2标准的TS流输出端相连,每个同步系统含有:(7.1)接口格式变换电路,包括:同步并行接口即SPI转换到异步串行接口即ASI的芯片,异步串行接口转换到同步并行接口的芯片;根据要求的传输流即TS流的接口格式,在信号输入时,ASI到SPI接口格式变换电路的输入端与接收端的传输网络适配器的TS流输出端相连;(7.2)寄存器,在数字电路中实现,它的输入端与格式变换电路的TS流输出端相连;(7.3)传输码流包头检测电路,在数字电路中实现,它的输入端与寄存器的输出端相连,它的输出是上述STS和MD值;(7.4)计数器,在数字电路中实现,它的被测信号输入端与传输码流包头检测电路的输出端相连,它的两个计数控制输入信号分别是来自接收端GPS接收机的10MHZ时钟和1pps脉冲,它的输出 (7) a plurality of synchronous receiving end systems that are connected to the input terminal TS stream output in line with the MPEG-2 standard each of the transport network adapters, each synchronization system comprising: (7.1) interface format conversion circuit, comprising: a synchronization i.e., converted to parallel interface SPI asynchronous serial interface chip ASI i.e., asynchronous serial interface conversion to synchronous parallel interface chip; format according to the interface requirements of the transport stream TS stream i.e., when the signal is input, the SPI interface ASI format conversion TS stream output end of the transmission network adapter input terminal and the receiving terminal of the circuit connected to; (7.2) register, implemented in digital circuitry, connected to its TS stream output of the input and the format conversion circuit; (7.3) transport stream packet header detection circuit, implemented in a digital circuit, its input terminal coupled to the output register, whose output is the above-mentioned MD value and the STS; (7.4) counter implemented in digital circuitry, which is the signal input of the transmission stream header detection circuit connected to the output, the count of its two input signals are derived from the control 10MHZ clock pulses 1pps receiving end and the GPS receiver, its output 本地测量延时信息;(7.5)延时电路,在数字电路中实现,它含有:计算附加延时的减法器,它的被减数输入端与传输码流包头检测电路的输出端相连,它的减数输入端与上述计数器的本地测量延时输出端相连;缓存器,它的一个输入端与减法器的输出端相连,另一个输入端与上述寄存器的TS流输出端相连;(7.6)数字锁相环电路,它的输入端与接收端GPS接收机的10MHz时钟信号输出端相连;(8)多个地面数字电视广播调制器,它的第一个输入端与锁相环电路的调制载波输出端相连,第二个输入端与延时电路的全局复位信号即Reset输出端相连,第三个输入端与延时电路的延时输出TS码流信号输出端相连。 Local measurement delay information; (7.5) delay circuit, implemented in digital circuits, comprising: calculating an additional delay subtracter minuend input terminal and the output terminal of transport stream header detection circuit connected to it the subtrahend input terminal of the local measurement delay of the counter is connected to an output terminal; buffer, which is connected to the output terminal and the input terminal of the subtractor, the other input terminal is connected to the TS output of said register; (7.6) digital phase locked loop circuit, 10MHz clock signal output terminal and its input terminal is connected to a GPS receiver receiving end; (8) a plurality of terrestrial digital TV broadcast modulator, modulating its first input terminal of the phase locked loop circuit carrier output connected to the second input terminal of the delay circuit, i.e., the global reset signal reset output terminal connected to a third input terminal coupled to the delay circuit delays the output signal output TS stream.

本发明提出的地面数字电视广播的单频网系统实现方法,其特征在于,它含有以下步骤:(1)设定大帧初始化包即MIP包的结构和MPEG-2的TS流的帧结构完全一致,它包括4字节的包头和184字节的有效载荷,其各部分组成如下:a)包头, The present invention is proposed digital terrestrial television broadcasting system SFN-implemented method, characterized in that it comprises the following steps: (1) setting a large frame initialization packet i.e. MIP packet and frame structure of the MPEG-2 TS stream completely consistency, which comprises a 4-byte payload header of 184 bytes, each of the following components: a) header,

b)同步指示,c)块长度,排除填充字节,d)指针域,它是一个2字节的二进制整数,它表示随后大帧的第一包距离此MIP包的TS流包数,e)同步时间标签即STS,第M个大帧中的MIP包的同步时间标签表示第M+1个大帧的实际起始时间与最近的由发射端GPS得到的参考脉冲即1pps之间的差值,f)最大延迟即MD,它表示从发射天线发出的数字基带信号中的第M+1个大帧开始时间和单频网适配器中的第M+1个大帧的开始时间的差值,最大处理的延时是1秒,g)CRC校验,共32比特,h)填充字节;(2)在中心发射端,由单频网适配器即SFN适配器没隔一个大帧在MPEG-2的传输流即TS中插入MIP包,大帧指一组TS流,有N包,N为正整数,其步骤如下:(2.1)变换接口格式当输入TS流的接口模式为同步并行接口即SPI模式时,则直接把输入信号接入;当输入TS流的接口模式为异步串行接口即ASI模式时,则要 b) synchronization instruction, c) block length, stuffing bytes excluded, d) pointer field, which is a 2-byte binary integer which represents the number of TS packets and then a first stream packet from this frame MIP large package, E ) i.e. synchronization time synchronization time tag label STS, the M-th frame to the MIP large package represents the actual start time of the M + 1 frame is large and the nearest end of the reference GPS pulse emission obtained i.e. a difference between 1pps value, f) the maximum delay i.e. MD, which indicates the difference between the start time of the first M + 1 large frame start time and a single digital baseband signal from the transmitting antenna frequency network adapter in the first M + 1 large frame , the maximum processing delay time is 1 second, g) CRC check, a total of 32 bits, h) padding bytes; (2) at the center of the transmitting end, i.e. from the SFN adapter SFN adapter is not a large compartment frame MPEG- 2 transport stream, i.e. TS insert MIP packet, large frame refers to a group of TS streams, there are N packet, N being a positive integer, comprises the following steps: (2.1) converting the interface format when the input TS stream interface mode is a synchronous parallel interface i.e. when the SPI mode, the input signal directly access; interface mode when the input TS stream is asynchronous serial interface mode ASI i.e., have 它转换为SPI模式;(2.2)通过检测空包的包标识,把输入TS流中的空包滤除,把数据存入缓存器中;(2.3)通过接收来自GPS接收机的1pps脉冲和10MHz时钟信号,按下式得出同步时间标签即STS,并和信道最大延时即MD一起按照MIP结构加入到一个符合MPEG-2标准的TS流包中,形成MIP;STS=1pps信号到大帧初始化包的时间(2.4)按照等间隔插入的原则,分以下三种情况,依次从缓冲器和MIP包形成电路中读取TS流数据,组合成输出的TS数据流:a)当MIP包指示信号有效时,优先输出MIP包;b)当MIP包指示信号无效且缓存器不空时,输出TS码流;c)当MIP包指示信号无效且缓存器为空时,输出符合MPEG-2标准的空包;(2.5)对最后输出的TS码流作节目时钟参考即节目参考时钟即PCR抖动校正; It is converted into SPI mode; (2.2) by detecting a null packet identification packet, the input stream TS empty packet was filtered off, the data stored in the buffer; (2.3) by receiving a pulse from the GPS receiver 1pps and 10MHz clock signal, synchronization time stamp obtained by the following formula i.e. the STS, and the maximum channel delay and added together MD i.e. MIP structure according to one TS packet stream in line with MPEG-2 standard, the formation MIP; STS = 1pps to large signal frame initialization packet time (2.4) in accordance with the principles of the inserted intervals, divided into the following three cases, the circuit sequentially reads data from the TS packet buffer and MIP is formed, TS output data streams into: a) indicating when the MIP packet signal is active, the priority output MIP packet; b) when the MIP packet indicates an invalid signal, and the buffer is not empty, the output TS stream; c) when a MIP packet indication signal is inactive and the buffer is empty, the output in line with MPEG-2 standard null packets; (2.5) of the TS stream output from the final code for the program clock reference that is a program clock reference PCR i.e. the shake correction;

(2.6)若要求输出的TS流的接口模式为ASI,则要变换接口模式为SPI;(2.7)传输网络适配器把收到的TS码流发向分布式网络;(3)在接收端从传输网络适配器中收到经过网络延时的TS流时,按以下步骤进行延时调整:(3.1)变换接口格式当输入TS流的接口模式为同步并行接口即SPI模式时,则直接把输入信号接入;当输入TS流的接口模式为异步串行接口即ASI模式时,则要把它转换为SPI模式;(3.2)同步系统从接收到的TS流中检测出MIP包,读出STS和MD信息;(3.3)同步系统通过接收来自GPS接收机的1pps脉冲和10MHz时钟信号,测量出本地延时信息;(3.4)同步系统按照下式计算附加延时:附加延时=STS+MD-本地延时;(3.5)同步系统按照附加延时输出TS码流;(3.6)同步系统按照要求的输出格式输出TS码流,确定是否需要进行接口模式转换;(3.7)GPS接收机输出的10MHz时钟信号作为同步系统中 (2.6) If the required interface mode is outputted from the TS stream ASI, will have to interface mode is converted SPI; (2.7) of the transmission network adapter, received TS stream sent to the distributed network; (3) at the receiving end from the transmitted network adapter receives the stream, the following steps for adjusting the delay through the network delay TS: (3.1) converting the interface format of TS stream mode when the input interface is a parallel interface that is synchronous SPI mode, the input signal is connected directly to in; interface mode when the input TS stream is asynchronous serial interface mode ASI i.e., put it into the SPI mode; (3.2) from the synchronous system detects the received TS packet stream in the MIP, and reads out the STS MD information; (3.3) 1pps synchronization system by receiving the pulse from the GPS receiver and the 10MHz clock signal, the local delay information measured; (3.4) synchronization system additional delay is calculated according to the following formula: delay = STS + MD- additional local delay; (3.5) synchronization system according to additional delay output TS stream; (3.6) according to the output format of the output synchronization system TS stream requirements, determine the need for interface mode conversion; 10MHz clock (3.7) GPS receiver output signal as a synchronous system 相环电路的输入信号,把锁相环的输出作为调制载波信号,把同步系统中的延时电路的Reset输出作为全局复位信号,连同同步系统中延时电路输出的延时TS流一起送往地面数字电视广播调制器。 Loop circuit input signals, the phase locked loop output as a modulated carrier signal, the Reset output synchronous delay circuit system as a global reset signal, the synchronization system together with the delay circuit outputs a delay with TS stream to terrestrial digital television broadcasting modulator.

本发明提出的单频网系统实现方案基于OFDM系统,利用了地面数字电视广播协议中的分级帧结构的周期性,设计出的SFN适配器在MPEG-2的TS流包中有规律地插入MIP,而接收端的同步系统根据计算出的附加延时将TS流延时输出,同时还为调制器提供了全网同步的载波调制,很好地实现了单频网技术中的频率同步与时间同步。 SFN scheme proposed by the present invention is implemented based on an OFDM system using a hierarchical frame structure periodic digital terrestrial television broadcasting protocol, the SFN adapter is designed in a regular MPEG-2 TS stream packets inserted in the MIP, and the receiver synchronization system in accordance with the calculated additional delay of the delay output TS stream, and also provides a network-wide synchronization carrier modulation of the modulator, to achieve a good frequency SFN art synchronize with time. 实际系统实验表明,本发明提出的地面数字电视广播的单频网实现方法简单可靠。 Experiments show that the actual system, digital terrestrial television broadcasting by the present invention SFN implementation is simple and reliable.

本发明提出的单频网实现方案已经用FPGA实现,并且应用在清华大学提出的地面数字多媒体广播传输系统中,实际试播和测试取得了良好的效果,图18即为单频网的实地试验示意图。 The present invention proposes a single frequency network implementations have been implemented with FPGA, while the application in the terrestrial digital multimedia broadcasting transmission system proposed by the Tsinghua University, the actual screening and testing achieved good results, a schematic view of FIG. 18 is the test field of a single frequency network .

附图说明 BRIEF DESCRIPTION

图1为用于模拟电视广播的多频网规划。 FIG. 1 is a multi-band analog television broadcast network planning.

图2为一种单频网覆盖示意图。 FIG 2 is a schematic diagram of a single-frequency network coverage.

图3为DVB-T标准中不同保护间隔下的最大延时扩展与发射机间的距离。 FIG 3 is the distance between the maximum delay spread at the transmitter with the DVB-T standard different guard interval.

图4为地面数字多媒体广播传输协议的分级帧结构。 FIG 4 is a hierarchical frame structure of DMB transmission protocol.

图5为地面数字多媒体广播传输协议中基本信号帧的结构。 FIG 5 is a structure of a terrestrial digital multimedia broadcasting basic transmission protocol of the signal frame.

图6为MPEG-2的TS包结构。 FIG 6 is a TS packet structure of MPEG-2.

图7为本发明提出的地面数字电视广播单频网系统的基本结构。 FIG 7 of the present invention provides a terrestrial digital television broadcast single frequency network the basic structure of the system.

图8为本发明提出的单频网实现方法中STS示意图。 SFN implemented method of Figure 8 is a schematic view of proposed invention STS.

图9为本发明提出的单频网实现方法中MIP的结构。 SFN implementation of FIG. 9 of the present invention proposes a structure of MIP.

图1O为本发明提出的单频网实现方法中接收端测量延时示意图。 FIG SFN 1O implementation of the present invention provides a receiving end measurement delay in FIG.

图11为MPEG-2复用器结构示意图。 FIG 11 is a schematic structural diagram of MPEG-2 multiplexer.

图12为本发明提出的单频网适配器的结构框图。 SFN adapter block diagram proposed in FIG. 12 of the present invention.

图13为本发明提出的接收端同步系统结构框图。 A block diagram of a receiving end synchronization system 13 of the present invention set forth in FIG.

图14为本发明提出的空包滤除电路的结构框图。 14 a block diagram of the null packets filtered proposed circuit of the present invention.

图15为本发明提出的复用及速率适配电路的结构框图。 And multiplexing block diagram of FIG rate adaptation circuit 15 of the present invention proposes.

图16为本发明提出的MIP检测电路的结构框图。 FIG 16 present a block diagram of a detection circuit MIP proposed invention.

图17为本发明提出的延时电路的结构框图。 17 a block diagram of the proposed delay circuit of the present invention.

图18为单频网实地试验示意图。 18 is a schematic view of a field test SFN.

具体实施方式 Detailed ways

下面将结合附图对本发明的理论分析和具体实施例进行详细描述。 Theoretical analysis of the present invention in conjunction with the accompanying drawings and will be described in detail specific embodiments.

图7显示了本发明提出的地面数字电视广播单频网系统的基本结构。 Figure 7 shows the basic structure of a digital terrestrial television broadcast single frequency network system proposed by the present invention. 本系统主要由单频网适配器、GPS接收机、支持单频网的地面数字电视广播调制器三部分组成。 The system consists of a single frequency network adapter, GPS receivers, digital terrestrial television broadcasting support modulator three parts SFN composition. 在中心发射端,SFN适配器在MPEG-2的TS流中定间隔地插入MIP包,MIP包中携带与GPS接收机相关的同步时间标签(STS)和到各个中继站的系统最大延时(MD)等信息。 In the center of the transmitting end, the SFN adapter into the MIP packet of MPEG-2 TS stream in the given interval, the system carries maximum delay MIP packet related to the GPS receiver synchronization time stamp (STS) and to the respective relay station (MD) and other information. 在各个中继站,同步系统检测MIP包,从中读出时间标签和最大延时,测量接收信号延时(MeasuredDelay),计算出附加延时(Additional Delay),并按照附加延时适当延迟TS流,使得各个中继站再次发射的信号同步。 In various relay stations, the system detects MIP synchronization packets, read from the tag and the maximum delay time, measures received signal delay (MeasuredDelay), calculates the additional delay (Additional Delay), and a suitable delay according to the additional delay TS stream, such that the relay station re-transmitting the signal of each synchronization.

本发明提出的地面数字电视广播的单频网系统主要由以下几个部分构成:1)MPEG-2复用器。 The present invention is proposed digital terrestrial television broadcasting SFN system consists of the following parts: 1) MPEG-2 multiplexer. 将基本业务流以及辅助数据复用,输出为TS流。 The basic service and auxiliary data stream multiplexing, to the output stream TS. 结构示意图如图11所示。 11 shows a schematic view of the structure of FIG.

2)GPS接收机。 2) GPS receiver. 主要用于为单频网适配器提供1pps参考脉冲以及10MHz同步时钟,现有的能够提供上述两个信号的GPS接收机都可以适用。 Is mainly used for the SFN adapter, and provide a reference pulse 1pps 10MHz synchronization clock, a conventional GPS receiver can provide the above-described two signals can be applied.

3)单频网适配器。 3) SFN adapter. 主要用于在MPEG-2的TS流中插入包含STS和MD信息的MIP包,以供接收端接收计算附加延时,插入的MIP包位置可以按照要求自行调整。 Primarily for insertion contained in the TS stream of MPEG-2 and MIP MD STS information packet, the receiving end for receiving additional delay calculation, the position of insertion of MIP packet can adjust as required. 同时,适配器还可以通过插入空包实现系统输入端的速率适配。 Meanwhile, the adapter may also be adapted to insert null packet rate achieved by the system input. SFN适配器的结构框图如图12所示。 SFN adapter structure diagram shown in Figure 12.

4)传输网络适配器。 4) transport network adapter. 在发射端,输入为同步并行接口(SPI)或异步串行接口(ASI)格式的TS流,输出为适合光纤或电缆等网络传输的信号;在接收端,输入输出相反,完成相反的功能。 At the transmitter, the input TS stream is synchronous parallel interface (SPI) or Asynchronous Serial Interface (ASI) format suitable for network transmission output fiber or cable signal; at the receiving end, opposite to the input and output, performs the reverse function. 这已有现成的的产品可以应用。 It has ready-made products can be applied.

5)分布式网络。 5) distributed network. 传输媒介可以是电缆或光纤等。 Transmission medium may be a cable or optical fiber.

6)同步系统。 6) synchronization system. 它一般位于地面数字电视广播调制器中,主要功能是通过本地的测量延时(Measured Delay)以及从接收到的MIP中得到的STS与MD计算得到附加延时,并将TS码流延时相应的时间。 It is usually located on the ground digital television broadcast modulator, the main function is to give additional delay by measuring the time delay of the local (Measured Delay) and STS and MD calculated from the received MIP, and the corresponding delay TS stream time. 同时还要给出全局复位信号和与GPS信号锁定的调制载波。 But also gives a global reset signal and a GPS signal lock modulated carrier. 同步系统结构框图如图13所示。 Synchronization system block diagram shown in Figure 13.

7)地面数字电视广播调制器。 7) terrestrial digital TV broadcasting modulator. 用于将经过同步调整后的TS流调制后发射出去,这种调制器已有实际产品。 After TS stream for the synchronized adjustment of the modulated emitted, such products have been used for the modulator.

本发明提出的SFN适配器的结构框图如图12所示。 The proposed structure of the present invention SFN adapter 12 of the block diagram shown in FIG. 其在TS码流中插入MIP以及进行速率适配的过程分为以下步骤完成:1)如果输入TS码流的接口模式为异步串行接口(ASI),则先将ASI格式的码流转换为同步并行接口(SPI)模式,在本系统中使用Cypress公司的CY7B933为核心芯片实现,也可使用与其功能相当的同类型芯片实现;如果输入TS码流的接口模式为SPI,则直接将输入信号接入。 MIP is inserted and the rate adaptation process in the TS stream is divided into the following steps is completed: 1) If the input interface TS stream mode asynchronous serial interface (ASI), the first stream format is converted ASI synchronous parallel Interface (SPI) mode, Cypress's in this system CY7B933 core chip may also be used to their function the same type of chip equivalent; if the input TS stream interface mode SPI, directly the input signal access.

2)通过检测空包的包标识PID=0x1FFF,将输入的TS码流中的空包滤除,然后将数据流存入缓存器中。 2) by the empty packet detecting packet identifier PID = 0x1FFF, TS stream the input null packets filtered off, and then stored in the buffer in the data stream. 具体电路结构如图14所示。 Specific circuit configuration as shown in FIG.

3)通过接收来自GPS接收机的1pps脉冲和10MHz时钟信号,计算出同步时间标签STS,并和信道最大延时信息MD一起按照图9所示的结构加入到一个符合MPEG-2标准的TS流包中,形成MIP。 3) by receiving the pulse from the GPS receiver 1pps 10MHz clock signal and calculates the synchronization time stamp the STS, and with the maximum channel delay and channel information is added to the MD line with a MPEG-2 standard according to the structure shown in FIG. 9 TS stream package, forming MIP.

4)按照等间隔的插入规则,依次从缓存器和MIP形成电路中读取TS流数据,输出的信号可分为三种情况:当MIP包指示信号有效时,优先传输MIP包;当MIP包指示信号无效且缓存器不空时,传输TS码流;当MIP包指示信号无效且缓存器为空时,传输符合MPEG-2标准的空包。 4) according to rules intervals inserted, are formed sequentially reading circuit TS data stream, the output signal may be divided into three cases from the buffer and MIP: MIP packet indication signal when valid, MIP packet transmission priority; MIP packet when invalid indication signal and the buffer is not empty, the transport stream TS; MIP packet when the signal indicates invalid and the buffer is empty, the transmission line with MPEG-2 standard null packets. 另外,还要将最后输出的TS流作PCR抖动校正。 Also, the final output stream TS as PCR jitter correction. 此即复用及速率适配电路,具体结构如图15所示。 Namely rate adaptation and multiplexing circuitry, the specific configuration shown in Figure 15.

5)如果要求输出的TS码流的接口模式为ASI,则要将符合SPI模式的TS流转换为符合ASI模式的TS流输出,在本系统中使用Cypress公司的CY7B923为核心芯片实现,也可使用与其功能相当的同类型芯片实现;如果要求输出TS码流的接口模式为SPI,则直接将信号输出。 5) If the required output interface mode TS stream is ASI, will have to meet the TS stream into TS stream SPI mode is an output mode in line with ASI, using the Cypress CY7B923 in the present system as the core chip, may be functionally equivalent thereto using the same type of chip; TS stream if the request output mode interface SPI, and outputs a signal directly.

其中,上述的空包滤除电路、缓存器电路、MIP形成电路和复用及速率适配电路都在FPGA中用硬件编程语言实现。 Wherein said filtered air bag circuit, buffer circuit, MIP circuit is formed and the rate adaptation and multiplexing circuit in the FPGA are implemented using hardware description language.

本发明提出的接收端同步系统结构框图如图13所示。 A receiving end synchronization system block diagram of the structure proposed by the invention as shown in Fig. 其延时输出TS码流的过程分为以下步骤完成:1)如果输入TS码流的接口模式为ASI,则先将ASI格式的码流转换为SPI模式,在本系统中使用Cypress公司的CY7B933为核心芯片实现,也可使用与其功能相当的同类型芯片实现;如果输入TS码流的接口模式为SPI,则直接将输入信号接入。 During which delay the output TS stream is divided into the following steps is completed: 1) If the input interface mode is ASI TS stream, the first stream into ASI format into SPI mode, the Cypress CY7B933 used in the present system core chip, functionally equivalent thereto may also be used in the same type of chip; if the input TS stream interface mode is SPI, directly access the input signal.

2)通过检查图9所示的MIP结构,从接收到的TS流中检测到MIP,读出其中的STS和MD信息。 2) MIP by checking the configuration shown in FIG. 9, is detected from the received TS stream to the MIP, STS and read out the information MD. MIP检测电路的结构如图16所示。 MIP structure detection circuit 16 shown in FIG.

3)通过接收来自GPS接收机的1pps脉冲和10MHz时钟信号,测量出本地延时信息Measured Delay。 3) by receiving the pulse from the GPS receiver 1pps and 10MHz clock signal, delay information measured local Measured Delay.

4)根据STS、MD以及本地延时Measured Delay信息按照下式计算出附加延时Additional Delay:STS+MD=Measured Delay+Additional Delay5)按照Additional Delay延时输出TS码流。 4) Measured Delay Additional Delay information showing additional delay calculated according to the following equation STS, MD and the local delay: STS + MD = Measured Delay + Additional Delay5) according to the output delay Additional Delay TS stream. 上述的延时电路的基本结构如图17所示。 The basic configuration of the delay circuit 17 shown in FIG.

6)如果要求输出的TS码流的接口模式为ASI,则要将符合SPI模式的TS流转换为符合ASI模式的TS流输出,在本系统中使用Cypress公司的CY7B923为核心芯片实现,也可使用与其功能相当的同类型芯片实现;如果要求输出TS码流的接口模式为SPI,则直接将信号输出。 TS stream converter 6) If the required output interface mode TS stream is ASI, SPI mode will have to comply with the ASI to meet the TS stream output mode, the Cypress CY7B923 used in the present system as the core chip, may be functionally equivalent thereto using the same type of chip; TS stream if the request output mode interface SPI, and outputs a signal directly.

7)将GPS接收机输出的10MHz时钟作为参考源,为地面数字电视广播调制器提供调制载波信号,这可以通过数字通信中常用的锁相环电路实现。 7) The 10MHz clock output from the GPS receiver as a reference source, providing a modulated carrier signal is digital terrestrial television broadcasting modulator, which can be achieved by commonly used in digital communication phase locked loop circuit.

其中,上述的MIP检测电路、延时电路都在FPGA中用硬件编程语言实现。 Wherein the above-described MIP detecting circuit, the delay circuits are implemented in a hardware description language using FPGA.

Claims (2)

1.地面数字电视广播的单频网系统,含有单频网适配器、GPS接收机、分布式网络和同步系统等,其特征在于,它含有:(1)MPEG-2复用器,包括:带有视频信号输入端的视频子系统,带有音频信号输入端的音频子系统,复用器,它由单节目复用电路和多节目复用电路串接而成,单节目复用电路的两个输入端分别与视频子系统、音频子系统的基本业务流输出端相连,多节目复用电路的几个输入端分别依次与单节目复用电路的几个传送流输出端相连;(2)单频网适配器即SFN适配器,它含有:(2.1)接口格式变换电路,包括:同步并行接口即SPI转换到异步串行接口即ASI的芯片,异步串行接口转换到同步并行接口的芯片;根据要求的传输流即TS流的接口格式,在信号输入时,ASI到SPI接口格式变换电路的输入端与MPEG-2复用器中多节目复用电路的TS流输出端相连;(2.2)空包 1. The terrestrial digital television broadcasting SFN, comprising SFN adapter, GPS receivers, distributed network synchronization system and the like, characterized in that it comprises: (1) MPEG-2 multiplexer, comprising: tape video signal input terminal of the video subsystem, audio subsystem with an audio signal input of the multiplexer, it is connected in series by a single program, and multiplexing circuits multiplexing circuit from the multi-program, a single program multiplexing circuit of two inputs end of the video subsystem, a basic service stream output respectively connected to the audio subsystem, the multi-program multiplexing circuit sequentially several inputs are respectively connected with a number of single program transport multiplex circuit output stream; (2) single frequency That SFN adapter network adapter, comprising: (2.1) interface format conversion circuit, comprising: a synchronous parallel interface SPI i.e. converted into asynchronous serial interface chip ASI i.e., asynchronous serial interface conversion to synchronous parallel interface chip; in accordance with the requirements of i.e., the transport stream TS stream interface format, when the signal is input, to the input of the ASI SPI interface format converting circuit and MPEG-2 multiplexer are connected by the multi-program TS stream multiplexing circuit output; (2.2) null packet 滤除电路,在数字电路中实现,包括:三个依次串接的移位寄存器,其中第一个移位寄存器的输入端与接口格式变换电路的TS流输出端相连;空包判断电路,它的三个输入端依次分别与第一、第二、第三个移位寄存器的TS流输入端相连;(2.3)缓存器,在数字电路中实现,它是一个FIFO存储器,它的输入端与空包虑除电路的经空包滤除后的TS流输出端相连;(2.4)大帧初始化包即MIP包的形成电路,在数字电路中实现,其中,MIP包的结构和MPEG-2的TS流的帧结构完全一致,它包括4字节的包头和184字节的有效载荷,具体由以下各部分组成,它们是对各个大帧初始化包都相同且对应的:a)包头,b)同步指示,c)块长度,排除填充字节,d)指针域,它是一个2字节的二进制整数,它表示随后大帧的第一包距离此MIP包的TS流包数,e)同步时间标签即STS,第M个大帧中的MIP包的同 Filtered off circuit, implemented in a digital circuit, comprising: three shift registers sequentially connected, which is connected to the TS output of the input shift register and a first interface format conversion circuit; null packets determination circuit, it the three input terminals are successively connected to the first, second, third terminal of the TS stream input shift register; (2.3) buffer, implemented in digital circuitry, which is a FIFO memory, and its input terminal null packet division circuit considered by the air stream output after the TS packets filtered connected; forming circuit (2.4) large frame initialization packet i.e. MIP packet, implemented in digital circuitry, wherein the MIP packet structure of MPEG-2, and the frame structure is exactly the same TS stream, which comprises a 4-byte payload header of 184 bytes, the specific composition of the following sections, each of which is the same for large and that the corresponding frame initialization packet: a) header, b) synchronization indication, c) block length, negative stuff byte, d) pointer field, which is a 2-byte binary integer which represents the number of streams TS packets subsequent frame from the first packet of this MIP large package, e) the synchronization That time label with STS, a large M-th frame to the MIP packets 步时间标签表示第M+1个大帧的实际起始时间与最近的由发射端GPS得到的参考脉冲即1pps之间的差值,f)最大延迟即MD,它表示从发射天线发出的数字基带信号中的第M+1个大帧开始时间和单频网适配器中的第M+1个大帧的开始时间的差值,最大处理的延时是1秒,g)CRC校验,共32比特,h)填充字节;(2.5)发送端的GPS接收机,它通过RS232接口与MIP包形成电路互连,它的10M信号和参考脉冲即1pps的输出端与MIP包形成电路的相应输入端相连;(2.6)复用及速率适配电路,在数字电路中实现,它含有:复用及速率适配子电路,它在数字电路中实现,它有四个信号输入端:MIP包指示有效信号、MIP包、缓存器空指示信号和滤除空包后的TS流信号,它的输出信号有三种情况:MIP包指示信号有效时,优先传输MIP包;MIP包指示信号无效且缓存器不空时,传输TS流;MIP包指示信号无效且 Step M + time label represents the actual start time of a frame reference pulse that is a large difference between the 1pps, f) i.e. the maximum delay MD and the nearest end GPS obtained by emission, which represents the number emitted from the transmitting antenna M +, difference of the start time of a frame of a large M + 1 large single frame start time and the baseband signal frequency network adapter, the maximum processing delay time is 1 second, g) CRC check, a total of 32 bits, h) stuffing bytes; (2.5) transmits GPS receiver end, which forms the circuit interconnects MIP packet via the RS232 interface, it 10M and a reference pulse signal that is the output of the MIP 1pps respective input packet forming circuit terminal coupled; (2.6) multiplexing and rate adaptation circuit, a digital circuit, comprising: multiplexing and rate adaptation sub-circuit, it is implemented in a digital circuit, which has four signal inputs: the MIP packet indication a valid signal, MIP packet, and a buffer empty signal indicating filtered air stream signal TS packet, its output signal in three ways: MIP packet indication signal is active, MIP packet transmission priority; MIP and the packet buffer is invalid indication signal is not empty, the transport stream TS; invalid indication signal and the MIP packets 存器为空时,传输空包;节目时钟参考即PCR校正电路,它的输入端与复用及速率适配子电路的输出端相连;(3)发送端的传输网络适配器,它的输入端与单频网适配器的符合MPEG-2标准的TS流输出端相连,它是市售产品;(4)分布式网络,它的输入端与传输网络适配器的网络传输信号输出端相连;(5)接收端的多个传输网络适配器,它们的每一个输入都是网络传输信号;(6)接收端的多个GPS接收机,它们的每一个的10MHz信号和参考脉冲即1pps的输出端与同步系统中的MIP检测电路的相应输入端相连,每一个的10MHz信号输出端还与同步系统中的锁相环的相应输入端相连;(7)接收端的多个同步系统,它们的输入端分别与各传输网络适配器的符合MPEG-2标准的TS流输出端相连,每个同步系统含有:(7.1)接口格式变换电路,包括:同步并行接口即SPI转换到异步串行接口即ASI的 Register is empty, transmitting null packets; Program Clock Reference i.e. PCR correction circuit having an input terminal and an output of the multiplexer and rate adaptation sub-circuit are connected; (3) the transmission side the transmission network adapter, its input terminal SFN adapter comply with the TS stream output is connected to the MPEG-2 standard, which is a commercially available product; (4) a distributed network, network transmission signal output terminal is connected to its input terminal and the transmission network adapter; (5) received a plurality of terminal transmission network adapters, each of which is an input signal transmission network; (6) a plurality of GPS receivers receiving end, each of them of a reference pulse and a 10MHz signal output of the synchronization system 1pps i.e. the MIP respective inputs connected to the detection circuit, 10MHz signal output of each further connected to a respective input of the phase locked loop synchronous system; (7) receiving a plurality of synchronization system terminal, an input terminal thereof, respectively, with each transport network adapter consistent with MPEG-2 standard TS stream output connected, each synchronization system comprising: (7.1) interface format conversion circuit, comprising: a synchronous parallel interface that is converted into asynchronous serial interface SPI i.e., the ASI 片,异步串行接口转换到同步并行接口的芯片;根据要求的传输流即TS流的接口格式,在信号输入时,ASI到SPI接口格式变换电路的输入端与接收端的传输网络适配器的TS流输出端相连;(7.2)寄存器,在数字电路中实现,它的输入端与格式变换电路的TS流输出端相连;(7.3)传输码流包头检测电路,在数字电路中实现,它的输入端与寄存器的输出端相连,它的输出是上述STS和MD值;(7.4)计数器,在数字电路中实现,它的被测信号输入端与传输码流包头检测电路的输出端相连,它的两个计数控制输入信号分别是来自接收端GPS接收机的10MHZ时钟和1pps脉冲,它的输出是本地测量延时信息;(7.5)延时电路,在数字电路中实现,它含有:计算附加延时的减法器,它的被减数输入端与传输码流包头检测电路的输出端相连,它的减数输入端与上述计数器的本地测量延时输 Sheet, asynchronous serial interface conversion to synchronous parallel interface chip; according to the interface format required by the transport stream i.e. TS stream, when the signal is input, the ASI to the input terminal and the receiving terminal SPI interface format converting circuit of the transmission network adapter TS stream an output terminal connected to; (7.2) register, implemented in digital circuitry, connected to its TS stream output of the input and the format conversion circuit; (7.3) transport stream packet header detecting circuit, implemented in digital circuits, its input register connected to the output terminal, its output value is above STS and MD; (7.4) counter implemented in digital circuitry, which is coupled to the signal input and the transport stream packet header detecting circuit output terminal, its two counting control input signals are derived from 1pps 10MHZ clock pulses and a receiving end of a GPS receiver, whose output is the local measurement delay information; (7.5) delay circuit, implemented in digital circuits, comprising: calculating additional delay subtractor whose minuend input terminal and the output terminal of transport stream header detection circuit is connected to local measurement delay its subtrahend input terminal and the input of the counter 端相连;缓存器,它的一个输入端与减法器的输出端相连,另一个输入端与上述寄存器的TS流输出端相连;(7.6)数字锁相环电路,它的输入端与接收端GPS接收机的10MHz时钟信号输出端相连;(8)多个地面数字电视广播调制器,它的第一个输入端与锁相环电路的调制载波输出端相连,第二个输入端与延时电路的全局复位信号即Reset输出端相连,第三个输入端与延时电路的延时输出TS码流信号输出端相连。 Terminal coupled; buffer, coupled to its output to an input of the subtractor, the other input terminal is connected to the TS output of said register; (7.6) a digital phase lock loop circuit, its input end and the receiving end GPS 10MHz clock signal output terminal connected to the receiver; (8) a plurality of terrestrial digital TV broadcast modulator, which is connected to the output terminal of a modulated carrier input of the phase locked loop circuit, the second input terminal of the delay circuit reset global reset signal that is connected to an output terminal, a third input terminal coupled to the delay circuit delays the output signal output TS stream.
2.地面数字电视广播的单频网系统实现方法,其特征在于,它含有以下步骤:(1)设定大帧初始化包即MIP包的结构和MPEG-2的TS流的帧结构完全一致,它包括4字节的包头和184字节的有效载荷,其各部分组成如下:a)包头,b)同步指示,c)块长度,排除填充字节,d)指针域,它是一个2字节的二进制整数,它表示随后大帧的第一包距离此MIP包的TS流包数,e)同步时间标签即STS,第M个大帧中的MIP包的同步时间标签表示第M+1个大帧的实际起始时间与最近的由发射端GPS得到的参考脉冲即1pps之间的差值,f)最大延迟即MD,它表示从发射天线发出的数字基带信号中的第M+1个大帧开始时间和单频网适配器中的第M+1个大帧的开始时间的差值,最大处理的延时是1秒,g)CRC校验,共32比特,h)填充字节;(2)在中心发射端,由单频网适配器即SFN适配器没隔一个大帧在MPEG-2的传输流即TS 2. The terrestrial digital television broadcasting SFN-implemented method, characterized in that it comprises the following steps: (1) setting a large frame initialization packet i.e. MIP packet and frame structure of the MPEG-2 TS stream is exactly the same, it includes a 4-byte payload header of 184 bytes, each of the following components: a) header, b) indicates synchronization, c) the block length, stuffing bytes excluded, d) pointer field, which is a 2-word section binary integer which represents the number of the synchronization time stamp TS stream packet followed by a first packet from this frame MIP large package, e) the STS synchronous time stamp i.e., the M-th frame to the MIP large packet represents M + 1 the actual start time of the nearest large frame and by the difference between the reference pulse i.e. 1pps, f) i.e. the maximum delay MD ends GPS emission obtained, M + 1 representing the first digital baseband signal from the transmission antenna M +, difference of the start time of a large frame start time and a big frame SFN adapter, the maximum processing delay time is 1 second, g) CRC check, a total of 32 bits, h) stuffing byte ; (2) at the center of the transmitting end, i.e., SFN adapter is not separated from the SFN adapter a large frame in a transport stream of MPEG-2 TS i.e. 插入MIP包,大帧指一组TS流,有N包,N为正整数,其步骤如下:(2.1)变换接口格式当输入TS流的接口模式为同步并行接口即SPI模式时,则直接把输入信号接入;当输入TS流的接口模式为异步串行接口即ASI模式时,则要把它转换为SPI模式;(2.2)通过检测空包的包标识,把输入TS流中的空包滤除,把数据存入缓存器中;(2.3)通过接收来自GPS接收机的1pps脉冲和10MHz时钟信号,按下式得出同步时间标签即STS,并和信道最大延时即MD一起按照MIP结构加入到一个符合MPEG-2标准的TS流包中,形成MIP;STS=1pps信号到大帧初始化包的时间(2.4)按照等间隔插入的原则,分以下三种情况,依次从缓冲器和MIP包形成电路中读取TS流数据,组合成输出的TS数据流:a)当MIP包指示信号有效时,优先输出MIP包;b)当MIP包指示信号无效且缓存器不空时,输出TS码流;c)当MIP包指示信号无效且缓 Insert MIP packet, large frame refers to a group of TS streams, there are N packet, N being a positive integer, comprises the following steps: (2.1) converting the interface format when the input TS stream interface mode is a synchronous parallel interface i.e. SPI mode, directly to access input signal; interface mode when the input TS stream is asynchronous serial interface mode ASI i.e., put it into the SPI mode; (2.2) by detecting a null packet identification packet, the input null packets in the TS stream filtered off, the data stored in the buffer; (2.3) and by receiving pulse 1pps 10MHz clock signal from the GPS receiver, the following formula obtained i.e. the STS synchronous time stamp, and the maximum channel delay, and that is in accordance with the MIP MD It was added to the TS packet structure of a standard MPEG-2 compliance form MIP; STS = 1pps large signal to the time frame initialization packet (2.4) is inserted in accordance with the principle of equal intervals, divided into the following three cases, in order from the buffer, and MIP TS stream packet forming circuit reads TS data stream, to output a combination: a) a signal indicating when valid packet MIP, MIP packet priority output; b) when a signal indicating an invalid MIP packet and the buffer is not empty, the output TS stream; c) when an invalid indication signal and slow MIP packet 存器为空时,输出符合MPEG-2标准的空包;(2.5)对最后输出的TS码流作节目时钟参考即PCR抖动校正;(2.6)若要求输出的TS流的接口模式为ASI,则要变换接口模式为SPI;(2.7)传输网络适配器把收到的TS码流发向分布式网络;(3)在接收端从传输网络适配器中收到经过网络延时的TS流时,按以下步骤进行延时调整:(3.1)变换接口格式当输入TS流的接口模式为同步并行接口即SPI模式时,则直接把输入信号接入;当输入TS流的接口模式为异步串行接口即ASI模式时,则要把它转换为SPI模式;(3.2)同步系统从接收到的TS流中检测出MIP包,读出STS和MD信息;(3.3)同步系统通过接收来自GPS接收机的1pps脉冲和10MHz时钟信号,测量出本地延时信息;(3.4)同步系统按照下式计算附加延时:附加延时=STS+MD-本地延时;(3.5)同步系统按照附加延时输出TS码流;(3.6)同步系统按照要求的输出格式 Register is empty, the output in line with MPEG-2 standard null packets; (2.5) of the TS code final output stream for program clock reference i.e. PCR jitter correction; (2.6) interface mode when the required output of the TS stream is ASI, interface mode will have converted to SPI; (2.7) of the transmission network adapter, received TS stream sent to the distributed network; (3) at the receiving end via the network delay TS stream received from the transport network adapter, press delay adjustment following steps: (3.1) converting the interface format when the input TS stream interface mode i.e. synchronous parallel interface SPI mode, the input signal directly access; interface mode when the input TS stream is an asynchronous serial interface i.e. when the ASI mode, then put it into SPI mode; (3.2) from the synchronous system detects the received TS packet stream in the MIP, STS and read information MD; (3.3) by receiving synchronization system from the GPS receiver 1pps pulse and a 10MHz clock signal, the local delay information measured; (3.4) additional delay synchronization system is calculated according to the following formula: delay = STS + MD- additional local delay; (3.5) synchronization system in accordance with an additional delay output code TS stream; (3.6) synchronization system in accordance with the output format required 输出TS码流,确定是否需要进行接口模式转换;(3.7)GPS接收机输出的10MHz时钟信号作为同步系统中锁相环电路的输入信号,把锁相环的输出作为调制载波信号,把同步系统中的延时电路的Reset输出作为全局复位信号,连同同步系统中延时电路输出的延时TS流一起送往地面数字电视广播调制器。 TS stream output, determine the need for interface mode conversion; 10MHz clock signal (3.7) GPS receiver output of the phase locked loop circuit as a synchronous system input signal, the phase locked loop output as a modulated carrier signal, the synchronization system reset the output of the delay circuit as a global reset signal, together with the synchronous delay circuit system, the delay output from the TS stream sent with digital terrestrial television broadcasting modulator.
CNB2004100034926A 2004-04-01 2004-04-01 Single-frequency network system of ground digital TV broadcast and its realizing method CN1312929C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNB2004100034926A CN1312929C (en) 2004-04-01 2004-04-01 Single-frequency network system of ground digital TV broadcast and its realizing method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNB2004100034926A CN1312929C (en) 2004-04-01 2004-04-01 Single-frequency network system of ground digital TV broadcast and its realizing method

Publications (2)

Publication Number Publication Date
CN1678068A true CN1678068A (en) 2005-10-05
CN1312929C CN1312929C (en) 2007-04-25

Family

ID=35050337

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB2004100034926A CN1312929C (en) 2004-04-01 2004-04-01 Single-frequency network system of ground digital TV broadcast and its realizing method

Country Status (1)

Country Link
CN (1) CN1312929C (en)

Cited By (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007118347A1 (en) * 2006-04-14 2007-10-25 Zte Corporation A cooperate broadcast system structure for cooperate the wire and wireless and a method thereof
WO2007118348A1 (en) * 2006-04-14 2007-10-25 Zte Corporation An inserting method and device for inserting control information, and a measuring method and device
CN100468989C (en) * 2006-06-30 2009-03-11 北京泰美世纪科技有限公司 Method for adapting single frequency net in digital broadcasting satellite system
CN100512436C (en) 2007-06-07 2009-07-08 上海交通大学 System clock feeding and recovering method for railway television single frequency network
CN100525250C (en) 2006-11-08 2009-08-05 北京新岸线移动多媒体技术有限公司 Method for realizing IP stream mode service utilizing MPE-FEC technique in T-MMB system
CN101162982B (en) 2006-10-12 2010-05-12 中兴通讯股份有限公司 TDD communication system and frame structure selecting method thereof
CN101018085B (en) 2006-12-08 2010-05-19 北京创毅视通科技有限公司 A method and system for providing the digital multi-media broadcast signal
CN101729235A (en) * 2008-10-23 2010-06-09 汤姆森许可贸易公司 Synchronised control method of a plurality of formatting equipment and stream formatting equipment
CN101252668B (en) 2007-12-26 2010-06-09 深圳创维数字技术股份有限公司 Digital television information broadcasting system and equipment
CN101547364B (en) 2009-05-05 2010-08-25 北京牡丹视源电子有限责任公司 Transport stream generator
CN101222281B (en) 2008-01-31 2010-10-13 北京创毅视讯科技有限公司 Single frequency net system and its synchronous system and method in mobile multimedia broadcast
CN101883272A (en) * 2010-06-09 2010-11-10 清华大学 Multi-service adaptation method based on DTMB (Digital Television Terrestrial Multimedia Broadcasting) single-frequency network system and implementation device thereof
CN101895330A (en) * 2010-06-08 2010-11-24 上海高清数字科技产业有限公司 Signal-uninterruption method and device used during mode switching of modulator of monochromatic network
US7876750B2 (en) 2006-04-04 2011-01-25 Samsung Electronics Co., Ltd. Digital broadcasting system and data processing method thereof
CN101422039B (en) 2006-06-16 2011-04-06 三星电子株式会社 Transmission stream generating device for generating transmission stream which additional data is stuffed in a payload area of a packet, digital broadcast transmitting/receiving device for transmitting/receiving transmission stream and method
CN101431499B (en) 2008-10-27 2011-04-27 宁波大学 Space-frequency modulation method for anti-interference digital television ground broadcasting transmitter
CN101237276B (en) 2007-01-30 2011-06-01 展讯通信(上海)有限公司 Mobile phone TV single-frequency network synchronization system and method based on mobile network
CN101110688B (en) 2007-06-29 2011-07-27 北京创毅视讯科技有限公司 Single frequency network system transmission method and single frequency network adapter
CN101835036B (en) 2009-03-13 2011-08-17 北京北广科技股份有限公司 Method for converting ASI code stream into SPI code stream and interface circuit for realizing same
CN102186106A (en) * 2011-05-04 2011-09-14 苏州全波通信技术有限公司 Clock synchronization device in single-frequency network
CN102264002A (en) * 2011-07-14 2011-11-30 中山爱科数字家庭产业孵化基地有限公司 A digital home interactive business network adapters and Implementation
CN101232323B (en) 2007-01-26 2012-03-14 展讯通信(上海)有限公司 Mobile phone television broadcasting system based on TD-SCDMA network
CN101690197B (en) 2007-06-26 2012-04-18 Lg电子株式会社 Digital broadcasting system and data processing method
CN101076145B (en) 2007-06-29 2012-04-18 北京创毅视讯科技有限公司 Mobile multi-medium broadcasting system, mono-frequency network system and synchronizing system
CN101527606B (en) 2009-03-26 2012-08-22 上海交通大学 Railway TV monochromatic network signal overlapping area tester
CN101536373B (en) 2006-11-07 2012-11-28 高通股份有限公司 Method and apparatus for reinforcement of broadcast transmissions in mbsfn inactive areas
CN101998285B (en) 2005-06-09 2012-12-12 桥扬科技有限公司 Methods and apparatus for power efficient broadcasting and communication systems
US8335280B2 (en) 2007-08-24 2012-12-18 Lg Electronics Inc. Digital broadcasting system and method of processing data in digital broadcasting system
CN101697588B (en) 2006-04-04 2013-01-30 三星电子株式会社 Digital broadcasting system and data processing method thereof
CN101911497B (en) 2008-01-02 2013-02-06 思科技术公司 Phase compensated renormalizable dynamic phase locked loop
US8391404B2 (en) 2007-08-24 2013-03-05 Lg Electronics Inc. Digital broadcasting system and method of processing data in digital broadcasting system
CN101707706B (en) 2007-05-15 2013-08-14 三星电子株式会社 Digital transmission and reception devices for transmitting and receiving streams, and processing methods thereof
CN103354528A (en) * 2013-06-28 2013-10-16 北京智谷睿拓技术服务有限公司 Method and device for multi-stream synchronization
US8670463B2 (en) 2007-06-26 2014-03-11 Lg Electronics Inc. Digital broadcast system for transmitting/receiving digital broadcast data, and data processing method for use in the same
CN103944851A (en) * 2014-04-03 2014-07-23 西安交通大学 Method and system for establishing OFDM single frequency network through MMDS device
US8964856B2 (en) 2007-08-24 2015-02-24 Lg Electronics Inc. Digital broadcasting system and method of processing data in digital broadcasting system
CN104579625A (en) * 2015-01-09 2015-04-29 中国传媒大学 DRM single-frequency network synchronization implementation method based on ARM and CPLD
CN105429745A (en) * 2015-12-30 2016-03-23 中国科学院上海高等研究院 Synchronization method and system for constructing single-frequency sub network
CN105847872A (en) * 2013-05-09 2016-08-10 蔡留凤 Ultra-high definition digital television signal emitter capable of increasing television program's resolutions

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1118195C (en) * 2000-08-25 2003-08-13 清华大学 Digital information transmission method and ground digital multimedia TV broadcasting system
CN1332556A (en) * 2001-04-27 2002-01-23 清华大学 Channel transmission method for ground digital multimeldia television broadcast system
CN1209920C (en) * 2001-08-28 2005-07-06 电子科技大学 Synchronous multicarrier spread spectrum ground digital TV transmission system
ITTO20020076A1 (en) * 2002-01-28 2003-07-28 Rai Radiotelevisione Italiana Procedure and cancellation apparatus of the reentry signal in unripetitore of gap filler type for single-frequency DVB-T networks.

Cited By (58)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101998285B (en) 2005-06-09 2012-12-12 桥扬科技有限公司 Methods and apparatus for power efficient broadcasting and communication systems
US7876750B2 (en) 2006-04-04 2011-01-25 Samsung Electronics Co., Ltd. Digital broadcasting system and data processing method thereof
US7929529B2 (en) 2006-04-04 2011-04-19 Samsung Electronics Co., Ltd. Digital broadcasting system and data processing method thereof
CN101697588B (en) 2006-04-04 2013-01-30 三星电子株式会社 Digital broadcasting system and data processing method thereof
CN101401318B (en) 2006-04-14 2012-05-23 中兴通讯股份有限公司 An inserting method and device for inserting control information, and a measuring method and device
WO2007118348A1 (en) * 2006-04-14 2007-10-25 Zte Corporation An inserting method and device for inserting control information, and a measuring method and device
WO2007118347A1 (en) * 2006-04-14 2007-10-25 Zte Corporation A cooperate broadcast system structure for cooperate the wire and wireless and a method thereof
CN101371576B (en) 2006-04-14 2011-03-02 中兴通讯股份有限公司 Cooperation broadcast system structure with wired and wireless cooperation, and method thereof
CN101422039B (en) 2006-06-16 2011-04-06 三星电子株式会社 Transmission stream generating device for generating transmission stream which additional data is stuffed in a payload area of a packet, digital broadcast transmitting/receiving device for transmitting/receiving transmission stream and method
CN100468989C (en) * 2006-06-30 2009-03-11 北京泰美世纪科技有限公司 Method for adapting single frequency net in digital broadcasting satellite system
CN101162982B (en) 2006-10-12 2010-05-12 中兴通讯股份有限公司 TDD communication system and frame structure selecting method thereof
CN101536373B (en) 2006-11-07 2012-11-28 高通股份有限公司 Method and apparatus for reinforcement of broadcast transmissions in mbsfn inactive areas
CN100525250C (en) 2006-11-08 2009-08-05 北京新岸线移动多媒体技术有限公司 Method for realizing IP stream mode service utilizing MPE-FEC technique in T-MMB system
CN101018085B (en) 2006-12-08 2010-05-19 北京创毅视通科技有限公司 A method and system for providing the digital multi-media broadcast signal
CN101232323B (en) 2007-01-26 2012-03-14 展讯通信(上海)有限公司 Mobile phone television broadcasting system based on TD-SCDMA network
CN101237276B (en) 2007-01-30 2011-06-01 展讯通信(上海)有限公司 Mobile phone TV single-frequency network synchronization system and method based on mobile network
CN101707706B (en) 2007-05-15 2013-08-14 三星电子株式会社 Digital transmission and reception devices for transmitting and receiving streams, and processing methods thereof
CN100512436C (en) 2007-06-07 2009-07-08 上海交通大学 System clock feeding and recovering method for railway television single frequency network
US9860016B2 (en) 2007-06-26 2018-01-02 Lg Electronics Inc. Digital broadcast system for transmitting/receiving digital broadcast data, and data processing method for use in the same
US10097312B2 (en) 2007-06-26 2018-10-09 Lg Electronics Inc. Digital broadcast system for transmitting/receiving digital broadcast data, and data processing method for use in the same
USRE46728E1 (en) 2007-06-26 2018-02-20 Lg Electronics Inc. Digital broadcasting system and data processing method
US8670463B2 (en) 2007-06-26 2014-03-11 Lg Electronics Inc. Digital broadcast system for transmitting/receiving digital broadcast data, and data processing method for use in the same
CN101690197B (en) 2007-06-26 2012-04-18 Lg电子株式会社 Digital broadcasting system and data processing method
US9490936B2 (en) 2007-06-26 2016-11-08 Lg Electronics Inc. Digital broadcast system for transmitting/receiving digital broadcast data, and data processing method for use in the same
US8374252B2 (en) 2007-06-26 2013-02-12 Lg Electronics Inc. Digital broadcasting system and data processing method
CN101110688B (en) 2007-06-29 2011-07-27 北京创毅视讯科技有限公司 Single frequency network system transmission method and single frequency network adapter
CN101076145B (en) 2007-06-29 2012-04-18 北京创毅视讯科技有限公司 Mobile multi-medium broadcasting system, mono-frequency network system and synchronizing system
US9755849B2 (en) 2007-08-24 2017-09-05 Lg Electronics Inc. Digital broadcasting system and method of processing data in digital broadcasting system
US8391404B2 (en) 2007-08-24 2013-03-05 Lg Electronics Inc. Digital broadcasting system and method of processing data in digital broadcasting system
US9369154B2 (en) 2007-08-24 2016-06-14 Lg Electronics Inc. Digital broadcasting system and method of processing data in digital broadcasting system
USRE47183E1 (en) 2007-08-24 2018-12-25 Lg Electronics Inc. Digital broadcasting system and method of processing data in digital broadcasting system
US8335280B2 (en) 2007-08-24 2012-12-18 Lg Electronics Inc. Digital broadcasting system and method of processing data in digital broadcasting system
US8964856B2 (en) 2007-08-24 2015-02-24 Lg Electronics Inc. Digital broadcasting system and method of processing data in digital broadcasting system
CN101252668B (en) 2007-12-26 2010-06-09 深圳创维数字技术股份有限公司 Digital television information broadcasting system and equipment
CN101911497B (en) 2008-01-02 2013-02-06 思科技术公司 Phase compensated renormalizable dynamic phase locked loop
CN101222281B (en) 2008-01-31 2010-10-13 北京创毅视讯科技有限公司 Single frequency net system and its synchronous system and method in mobile multimedia broadcast
CN101729235B (en) 2008-10-23 2014-02-26 汤姆森许可贸易公司 Synchronised control method of a plurality of formatting equipment and stream formatting equipment
CN101729235A (en) * 2008-10-23 2010-06-09 汤姆森许可贸易公司 Synchronised control method of a plurality of formatting equipment and stream formatting equipment
CN101431499B (en) 2008-10-27 2011-04-27 宁波大学 Space-frequency modulation method for anti-interference digital television ground broadcasting transmitter
CN101835036B (en) 2009-03-13 2011-08-17 北京北广科技股份有限公司 Method for converting ASI code stream into SPI code stream and interface circuit for realizing same
CN101527606B (en) 2009-03-26 2012-08-22 上海交通大学 Railway TV monochromatic network signal overlapping area tester
CN101547364B (en) 2009-05-05 2010-08-25 北京牡丹视源电子有限责任公司 Transport stream generator
CN101895330A (en) * 2010-06-08 2010-11-24 上海高清数字科技产业有限公司 Signal-uninterruption method and device used during mode switching of modulator of monochromatic network
CN101895330B (en) 2010-06-08 2013-07-31 上海高清数字科技产业有限公司 Signal-uninterruption method and device used during mode switching of modulator of monochromatic network
CN101883272A (en) * 2010-06-09 2010-11-10 清华大学 Multi-service adaptation method based on DTMB (Digital Television Terrestrial Multimedia Broadcasting) single-frequency network system and implementation device thereof
CN102186106A (en) * 2011-05-04 2011-09-14 苏州全波通信技术有限公司 Clock synchronization device in single-frequency network
CN102186106B (en) 2011-05-04 2014-01-22 苏州全波通信技术有限公司 Clock synchronization device in single-frequency network
CN102264002A (en) * 2011-07-14 2011-11-30 中山爱科数字家庭产业孵化基地有限公司 A digital home interactive business network adapters and Implementation
CN102264002B (en) 2011-07-14 2013-06-05 中山爱科数字家庭产业孵化基地有限公司 Network adapter of digital household interactive service and realization method thereof
CN105847872A (en) * 2013-05-09 2016-08-10 蔡留凤 Ultra-high definition digital television signal emitter capable of increasing television program's resolutions
CN103354528B (en) * 2013-06-28 2017-05-03 北京智谷睿拓技术服务有限公司 Method and apparatus for synchronizing multiple streams
CN103354528A (en) * 2013-06-28 2013-10-16 北京智谷睿拓技术服务有限公司 Method and device for multi-stream synchronization
CN103944851B (en) * 2014-04-03 2017-10-20 西安交通大学 The method of using the equipment set up mmds ofdm SFN system and
CN103944851A (en) * 2014-04-03 2014-07-23 西安交通大学 Method and system for establishing OFDM single frequency network through MMDS device
CN104579625A (en) * 2015-01-09 2015-04-29 中国传媒大学 DRM single-frequency network synchronization implementation method based on ARM and CPLD
CN104579625B (en) * 2015-01-09 2018-06-12 中国传媒大学 Based drm single arm and cpld frequency network synchronization method implemented
CN105429745B (en) * 2015-12-30 2019-04-16 中国科学院上海高等研究院 It is a kind of for constructing the synchronous method and system of single-frequency subnet
CN105429745A (en) * 2015-12-30 2016-03-23 中国科学院上海高等研究院 Synchronization method and system for constructing single-frequency sub network

Also Published As

Publication number Publication date
CN1312929C (en) 2007-04-25

Similar Documents

Publication Publication Date Title
US5963557A (en) High capacity reservation multiple access network with multiple shared unidirectional paths
KR100900531B1 (en) System and method for synchronizing a transport stream in a single frequency network
CN101652995B (en) Digital broadcasting system and method of processing data
CN1703871B (en) Home network device
US8261308B2 (en) Mapping of network information between data link and physical layer
US5923755A (en) Multi-service data receiver architecture
US20060133429A1 (en) Device and method for demultiplexing received transport stream in digital broadcasting receiver
CN1943150B (en) Use of signaling for auto-configuration of modulators and repeaters
CN106027578B (en) Broadcast singal sending device and the method for sending broadcast singal
KR100552678B1 (en) Apparauts and method for transmitting and receiving with reducing the setup time of data packet
US20130003819A1 (en) Ofdm signal transmission method, transmission apparatus, and reception apparatus
US6785903B1 (en) Digital television translator with PSIP update
CN1739305B (en) Broadcast hand-over in a wireless network
CN1236572C (en) Digital broadcast system
US20090094356A1 (en) Associating Physical Layer Pipes and Services Through a Program Map Table
JP3743742B2 (en) Data transmission system
US7903574B2 (en) Service discovery mechanism in broadcast telecommunication network
US20090092037A1 (en) Wireless Interactive System and Method
JP2010532649A (en) Mobile television broadcasting system
KR101088599B1 (en) Method and device for processing a dvb-hdigital video broadcasting-handheld compliant transport stream
US9882731B2 (en) Broadcasting signal transmitter/receiver and broadcasting signal transmission/reception method
CN101715121A (en) Digital broadcast transmitter/receiver having improved receiving performance and signal processing method thereof
JP2006345493A (en) Apparatus and method for transmitting and receiving broadcasting in digital multimedia broadcasting system
KR20080057654A (en) Digital broadcasting system and data processing method
CN1247026C (en) Mobile terminal oriented multimedia broadcasting system and implementing method thereof

Legal Events

Date Code Title Description
C06 Publication
C10 Entry into substantive examination
C14 Grant of patent or utility model
LICC Enforcement, change and cancellation of record of contracts on the licence for exploitation of a patent or utility model
CF01 Termination of patent right due to non-payment of annual fee