WO2010091622A1 - Mobile multimedia broadcast transmission system - Google Patents

Mobile multimedia broadcast transmission system Download PDF

Info

Publication number
WO2010091622A1
WO2010091622A1 PCT/CN2010/070476 CN2010070476W WO2010091622A1 WO 2010091622 A1 WO2010091622 A1 WO 2010091622A1 CN 2010070476 W CN2010070476 W CN 2010070476W WO 2010091622 A1 WO2010091622 A1 WO 2010091622A1
Authority
WO
WIPO (PCT)
Prior art keywords
mobile multimedia
multimedia broadcast
interleaver
subcarriers
transmitting system
Prior art date
Application number
PCT/CN2010/070476
Other languages
French (fr)
Chinese (zh)
Inventor
白栋
葛啟宏
陶涛
王军伟
Original Assignee
北京泰美世纪科技有限公司
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 北京泰美世纪科技有限公司 filed Critical 北京泰美世纪科技有限公司
Publication of WO2010091622A1 publication Critical patent/WO2010091622A1/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0056—Systems characterized by the type of code used
    • H04L1/0071—Use of interleaving
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/0001—Arrangements for dividing the transmission path
    • H04L5/0003—Two-dimensional division
    • H04L5/0005—Time-frequency
    • H04L5/0007—Time-frequency the frequencies being orthogonal, e.g. OFDM(A), DMT
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0058—Allocation criteria
    • H04L5/0064—Rate requirement of the data, e.g. scalable bandwidth, data priority

Definitions

  • the present invention relates to the field of digital information transmission technologies, and more particularly to a mobile multimedia broadcast transmission system. Background technique
  • wireless broadcast communication has the characteristics of wide coverage and large program capacity, and its biggest advantage is that it has broadcastability, realizes point-to-multipoint, and has high transmission bandwidth under low-cost conditions. Therefore, as an important part of the information and communication industry, wireless communication broadcasting plays an important role in the construction of national information infrastructure, the realization of universal services and the national information security strategy.
  • Mobile multimedia broadcasting refers to small-screen, small-sized, mobile and portable handheld terminals such as mobile phones, PDAs, MP3s, MP4s, digital cameras, laptops, etc., which can receive broadcast TV programs and information services anytime and anywhere. system.
  • mobile multimedia broadcasting that provides some services is based on existing mobile communication networks and streaming media.
  • the above communication methods cannot be used for existing mobile multimedia broadcasting performance. Further improvement is difficult to provide users with a satisfactory viewing experience.
  • the use of broadcast network and communication network cooperation work to provide a high-quality broadcast multimedia service for mobile terminals becomes mobile multimedia broadcast research and development. The main basis.
  • the present invention provides a mobile multimedia broadcast transmitting system, comprising: an RS encoding and a byte interleaver for performing RS encoding and byte interleaving on an upper layer data stream through a physical logical channel; LDPC encoder, Performing LDPC encoding on the data output by the RS encoding and the byte interleaver to obtain bit data; a bit interleaver for performing bit interleaving on bit data output by the LDPC encoder; a constellation mapper for The data output by the bit interleaver performs constellation mapping; the frequency domain symbol generator is configured to multiplex the scattered pilot, the continuous pilot including the system information, and the data symbols mapped by the constellation to form an OFDM frequency domain converter, An OFDM time domain symbol is generated after the frequency domain symbol output by the scrambler is subjected to an IFFT transform; and a time domain framer is configured to form the OFDM time domain symbol into a time slot, and connect the group a physical layer signal frame;
  • the physical layer signal frame length is 1 second, and includes 40 time slots having a length of 25 milliseconds, the time slot includes 1 beacon and 53 OFDM symbols, and the beacon includes 1 Transmitter identification signal and two identical synchronization signals, the transmitter identification signal is obtained by BPSK mapping and IFFT transformation in sequence by frequency domain random sequence, and then obtained by cyclic extension, and the synchronization sequence intercepts frequency domain random sequence Then, BPSK and IFFT are sequentially obtained and obtained.
  • the synchronization signal (t) is a band-limited pseudo-random signal, and the length 3 ⁇ 4 is 204.8 ⁇ .
  • ⁇ () is generated by mapping, mapping mode for:
  • the binary pseudo-random sequence is generated by a linear feedback shift register, the initial value of the shift register is 01110101101, and the generator polynomial is: x"+x 9 +l.
  • the expression of the generator polynomial of the RS U92, ⁇ ) code is;
  • the upper layer data stream is input into an RS code and a byte interleaver column by column from left to right in a byte unit, wherein the RS code is encoded in a row, and the start word of the byte interleaver
  • the section map is sent at the beginning of a time slot.
  • the output block length of the LDPC encoding is 9216 bits
  • the code rates are 1/2 and 3/4, respectively, corresponding to different code rates
  • the corresponding interleaving modes of the byte interleaver are respectively :
  • MI is the number of lines of the byte interleaver
  • all bytes in the byte interleaver are Mix 192 bytes.
  • the bit interleaver uses a block interleaver of 384 x 216; bit data output from the LDPC encoder is sequentially written into each line of the block interleaver in order from top to bottom, until The entire block interleaver is filled, and then read out from left to right in columns, wherein the output of the bit interleaver is aligned with the time slot.
  • the frequency domain symbol generator multiplexes 234 discrete pilots, 76 consecutive pilots, and 1566 data subcarriers in each OFDM symbol into 1876 active subcarriers.
  • the 76 consecutive pilots use 0, 6, 66, 76, 92, 132, 150, 170, 206, 228, 260, 294, 296 of the 1876 active subcarriers, 328, 338, 382, 392, 406, 462, 474, 480, 494, 552, 562, 582, 624, 630, 668, 738, 744, 760, 790, 806, 834, 850, 922, 937, 938, 952, 1024, 1040, 1068, 1084, 1114, 1130, 1172, 1206, 1210, 1244, 1250, 1292, 1312, 1322, 1380, 1394, 1400, 1412, 1468, 1482, 1492, 1536, 1546, 1578, 1580, 1614, 1646, 1668, 1704, 1724, 1742, 1782, 1798, 1808, 1868, 1875 subcarriers, and in the sixth, 406, 1084, 1482, 66, 46
  • the subcarrier number m corresponding to the scattered pilot in the OFDM symbol is:
  • the generator polynomial of the pseudo random sequence used by the scrambler is: ⁇ 12 + ⁇ ⁇ + ⁇ 8 + ⁇ 6 + ⁇ ; the scrambling code is divided into 8 modes, corresponding register initial The values are:
  • the IFFT converter places 1876 effective subcarriers on the 1st to 938th and 11th to 20thth subcarriers of 2048 subcarriers and performs 2048 point IFFT conversion.
  • the time domain framer sequentially adds the modulated OFDM symbols to the guard interval, the synchronization signal, and the transmitter identification signal to form a time slot, and then connects the 40 time slots to form a physical layer signal frame.
  • the system transmitter identification signals and synchronization are performed.
  • the signal is properly set up to provide stable system information to the system.
  • the RS code is optimized according to the operating bandwidth of the system, and the appropriate coding mode is selected according to different channel conditions. Accordingly, the byte interleaver is optimized, and byte interleaving is performed using reasonable interleaving parameters.
  • the continuous pilot, the scattered pilot, and the digital subcarrier of the system are reasonably set and allocated, so that the mobile multimedia broadcast transmitting system appropriately sets the system overhead and effectively utilizes the spectrum resource to transmit data.
  • FIG. 1 is a schematic structural diagram of a mobile multimedia broadcast transmitting system according to the present invention.
  • FIG. 2 is a schematic structural diagram of a physical channel logical channel of a broadcast channel of a mobile multimedia broadcast transmitting system of the present invention
  • FIG. 3 is a flow chart of logical channel coding and modulation of a physical layer of a mobile multimedia broadcast transmitting system according to the present invention
  • FIG. 4 is a schematic diagram of slot division and frame structure of a physical layer signal frame formed by slot grouping
  • Figure 5 is a schematic structural diagram of a beacon
  • FIG. 6 is a schematic structural diagram of a pseudo random sequence generator of a synchronization signal
  • FIG. 7 is a schematic structural diagram of an OFDM symbol
  • Figure 8 is a schematic view showing the overlap between guard intervals
  • Figure 10 is a schematic diagram of a byte interleaver and RS (192, K) coding
  • FIG. 11 is a schematic diagram of bit interleaving of an LDPC-encoded bit stream
  • FIG. 12 is a schematic diagram of a pilot multiplexing mode for allocating subcarriers of an OFDM symbol to data symbols, discrete pilots, and continuous pilots;
  • Figure 13 is a schematic diagram of a PRBS generation method
  • FIG. 14 is a schematic diagram of a OFDM symbol subcarrier structure. detailed description
  • the mobile multimedia broadcast transmitting system proposed by the present invention comprises: an RS encoding and a byte interleaver, an LDPC encoder, a bit interleaver, a constellation mapper, a frequency domain symbol generator, a scrambler, and an IFFT. Converter, time domain framer, transmitter.
  • the RS encoding and the byte interleaver are configured to perform RS coding and byte interleaving on the upper layer data stream by using a physical logical channel;
  • the LDPC encoder is configured to perform LDPC encoding on the data output by the RS encoding and the byte interleaver to obtain bit data;
  • the interleaver is configured to perform bit interleaving on the bit data output by the LDPC encoder;
  • the constellation mapper is configured to perform constellation mapping on the data output by the bit interleaver;
  • the frequency domain symbol generator is configured to use the scattered pilot, the continuous pilot including the system information, and
  • the data symbols of the constellation mapping are multiplexed together to form an OFDM frequency domain symbol;
  • the frequency domain symbols used by the scrambler for the output of the device are subjected to IFFT transform to generate OFDM time domain symbols; and
  • the time domain framing device is configured to compose OFDM time domain symbols After the time slot, the connection constitutes a physical
  • the mobile multimedia broadcast transmitting system proposed by the present invention can provide the user with high Multimedia programs such as digital audio broadcasting and digital video broadcasting.
  • the invention defines functional modules of the physical layer capable of adapting the upper layer data stream of the mobile multimedia broadcast transmission system in the 5 MHz frequency band, and gives the frame structure, channel coding and modulation of the physical layer transmission signal of the mobile multimedia broadcast channel. technology.
  • the physical layer of the broadcast channel defined by the present invention adapts different requirements of the transmission rate of the various types of applications in the upper layer through the physical layer logical channel.
  • the physical layer logical channel supports multiple encoding and modulation methods to meet the different signal quality requirements of different applications and different transmission environments.
  • the physical layer of the broadcast channel defined by the present invention supports two networking modes, a single frequency network and a multi-frequency network, and different transmission modes and parameters can be selected according to actual application characteristics and networking environment.
  • a hybrid mode that supports multiple applications, matching application characteristics to transmission modes, and achieving application flexibility and economy.
  • FIG. 2 it is a schematic diagram of a physical structure logical channel structure of a broadcast channel of a mobile multimedia broadcast transmitting system of the present invention.
  • the physical layer provides a broadcast channel for the upper layer application through the Physical Logical Channel (PLCH), including the control logical channel CLCH and the service logical channel SLCH.
  • PLCH Physical Logical Channel
  • Each physical layer logical channel can be transmitted using one or more time slots within a 5 MHz digital television bandwidth.
  • the physical layer separately encodes and modulates each physical layer logical channel. Depending on the coding and modulation parameters, the physical layer logical channels can provide different transmission capacities.
  • FIG. 3 is a flow chart showing the logical channel coding and modulation of the physical layer of the mobile multimedia broadcast transmitting system of the present invention.
  • the input data stream of the physical layer logical channel is subjected to forward error correction coding, interleaving, and constellation mapping, and is multiplexed with the scattered pilot and the continuous pilot to perform OFDM modulation.
  • the modulated signal forms a physical layer signal frame after being inserted into the frame header. It is then transmitted after baseband to RF conversion.
  • the physical layer logical channels are divided into a Control Logical Channel (CLCH) and a Service Logical Channel (SLCH).
  • CLCH Control Logical Channel
  • SLCH Service Logical Channel
  • the control logical channel is used to carry system configuration information and is transmitted in the 0th time slot of the system using a fixed channel coding and modulation model.
  • FIG. 4 is a schematic diagram of slot division and frame structure of a physical layer signal frame formed by slot grouping.
  • the system physical layer signal is 1 frame every 1 second, and each frame is divided into 40 time slots (Timelot, TS), and the length of each time slot is 25MHzs.
  • Each slot includes 1 beacon and 53 OFDM modulated data blocks.
  • FIG. 5 is a schematic diagram of the structure of the beacon. As shown, the beacon includes two identical sync signals and a transmitter identification signal (ID).
  • ID transmitter identification signal
  • the synchronization signal is a band-limited pseudo-random sequence, and the length is recorded as , and the value is 204.8 ⁇ .
  • the formula generated by the sync signal is:
  • a pseudo-random BPSK modulated signal carrying a binary sequence; ⁇ (0 is generated by mapping, and the mapping method is: .
  • the binary pseudo-random sequence PN is generated by a linear feedback shift register as shown in Figure 6.
  • the generator polynomial is: ⁇ "+ ⁇ 9 +1.
  • the initial value of the shift register is the same for each sync signal.
  • the transmitter identification signal D (t) is a band-limited pseudo-random signal used to identify different transmitters.
  • the length of & D (t) is denoted as T m and the value is 36.0 ⁇ .
  • the transmitter identification signal is:
  • the BPSK modulated signal X ID ⁇ P> carrying the transmitter identification sequence is generated by mapping the transmitter identification sequence TxIDil.
  • the mapping manner is:
  • the above transmitter identification sequence ⁇ / ⁇ )) is a pseudo-random sequence of length 117 bits.
  • the transmitter identification sequence includes a total of 256 sequences, wherein the sequence 0 to sequence 127 are area identifiers, which are used to identify the region where the transmitter is located, and the even time slots in the inserted signal frame are transmitted: the 0th time slot, the 2nd time slot, ...;; Sequences 128 ⁇ 255 are transmitter identifiers used to identify different transmitters in the same area, which are transmitted in odd time slots in the inserted signal frame: 1st time slot, 3rd time slot, .. . . .
  • the transmitter identification sequence is defined by a hexadecimal sequence that maps to the binary transmitter identification sequence in the order of the most significant bits.
  • the user can provide high quality mobile multimedia services, and the above technical solutions are based on the technical characteristics of the system, and the system transmitter identification signals,
  • the synchronization signal is properly set up to provide stable system information to the system.
  • FIG. 7 it is a schematic structural diagram of an OFDM symbol.
  • the OFDM symbol is composed of a cyclic prefix (CP) and an OFDM symbol body.
  • the cyclic prefix length TCP is 51.2us, that is, 256 samples after the IFFT
  • the OFDM symbol length TS is 409.6us, that is, 2048 samples after the IFFT.
  • the transmitter identification signal, the synchronization signal and the adjacent OFDM symbols overlap each other by a guard interval (GD), and the guard interval GD has a length TGD of 2.4 us, that is, 12 samples after the IFFT. Between adjacent symbols, the tail GD of the previous symbol and the head GD of the latter symbol are weighted by the window function and superimposed as shown in Fig. 8.
  • the window function expression is:
  • T is a constant and is the length of the guard interval.
  • the selection of the guard interval signal is shown in Figure 9.
  • byte interleaver As shown in Figure 10, a schematic diagram of the byte interleaver and RS (192, K) coding
  • the byte interleaver is a block interleaver of MI rows and 192 columns.
  • the number of lines M1 of the byte interleaver is determined by the byte interleave mode and the LDPC code rate, as shown in Table 2:
  • the truncation code RS (192, K) is encoded as follows: Add 63 all "0" bytes before the ⁇ input information bytes, and construct the input sequence of the original RS (255, ⁇ ) system code. ' J (0,0,-- ⁇ ,0, ⁇ 0 , ⁇ ⁇ ,---, ⁇ ⁇ _ ⁇ ) , generates a codeword after encoding (0,0, ⁇ A m 0 ,mf , ⁇ 0 , ⁇ 255 — ⁇ — , and then add the added bytes from the codeword, that is, the codeword of the 192-byte truncated RS code is (mo'mf'm Po'pd M- .
  • the input information sequence polynomial is:
  • the method of encoding and byte interleaving is as follows: The data block is transferred in bytes, from left to right, into the block interleaver, M1 bytes per column, until the Kth column is completed. The RS code is encoded in rows, and the check byte is padded to the next 192-K column. The encoded data is output column by column from left to right in the order of input until the 192 columns are all completed.
  • the above RS coding and byte interleaving are performed in units of physical logical channels, and upper layer data packets of the same physical logical channel are sequentially input into a byte interleaver for byte interleaving and RS coding.
  • the first byte of column 0 of the byte interleaver is defined as the starting byte of the byte interleaver.
  • the output of the byte interleaver each time Mi x 192 bytes is always mapped on an integer number of time slots, where the start word of the byte interleaver
  • the section map is sent at the beginning of a time slot.
  • the RS coding is optimized according to the working bandwidth of the system, and the appropriate coding mode is selected according to different channel conditions. Accordingly, the byte interleaver is optimized, and the byte interleaving is performed using reasonable interleaving parameters.
  • the above-mentioned RS coded and byte-interleaved transmission data is mapped to an 8-bit bit stream and sent to the LDPC encoder according to the principle of high-order bit priority transmission.
  • the first byte of column 0 of the byte interleaver is defined as the start byte of the byte interleaver whose highest bit is always mapped to the first bit of the LDPC input block.
  • the LDPC encoding configuration is shown in Table 3:
  • the LDPC code is given by the check matrix H, and the H matrix is generated as follows:
  • FIG. 11 it is a schematic diagram of bit interleaving of an LDPC-encoded bit stream.
  • the bit interleaver uses a 384 x 216 block interleaver.
  • the LDPC-encoded binary sequence is sequentially written to each line of the block interleaver in order from top to bottom until the entire interleaver is filled, and then read from left to right in columns.
  • the output of the bit interleaver is aligned with the time slot, i.e., the first bit transmitted in each time slot is always defined as the first bit of the bit interleaver output.
  • FIG. 12 is a schematic diagram of a pilot multiplexing manner of allocating subcarriers of an OFDM symbol to data symbols, discrete pilots, and continuous pilots.
  • the oblique line part is a continuous pilot signal
  • the black part is a discrete pilot signal
  • the white part is a data symbol obtained by constellation mapping.
  • the illustrated pilot multiplexing multiplexes the data symbols, the scattered pilots, and the continual pilots to form an OFDM frequency domain symbol.
  • the continuous pilot uses 0, 6, 66, 76, 92, 132, 150, 170, 206, 2 22288, 2266U0, 229944, 229966, 332288, 333388, 382, 392, 406, 462, 474, 480, 494, 552, 562, 582, 624, 630, 668, 738, 744, 760, 790, 806, 834, 850, 922, 937, 938, 952, 1024, 1040, 1068, 1084, 1114, 1130, 1172, 1206, 1210, 1244, 1250, 1292, 1312, 1322, 1380, 1394, 1400, 1412, 1468, 1482, 1492, 1536, 1546, 1578, 1580, 1614, 1646, 1668, 1704, 11772244,, 11774422, 11778822,, 11779988, 11 808, 1868, 1875 subcarriers, a total of 76.
  • a total of 64 carriers carry 16-bit system information.
  • the system information bits are transmitted on four consecutive pilots using a 4-fold repetition coding mapping. The mapping relationship is shown in Table 4, and the system information is specifically shown in Table 5. The remaining consecutive pilots transmit "0". Bit ⁇ subcarrier number
  • bit0 ⁇ bit5 are the current slot number, ranging from 0 ⁇ 39;
  • bit 6 is a byte interleaver synchronization identifier.
  • the time slot is identified as a byte interleaver start time slot
  • bit 7 is a control logical channel change indication, which instructs the terminal to control the logical channel configuration information change by means of differential modulation.
  • the difference mode is as follows: Assume that the previous frame bit7 transmits a, 0 or 1, and the system control channel configuration information will be changed in the next frame, then it is transmitted and held in this frame until the next change occurs.
  • bit8 ⁇ bitl5 is reserved.
  • Continuous pilot with 0 ⁇ /2 + The -V2/2-72/2 j mode is mapped to the subcarriers.
  • the symbols transmitted on the same consecutive subcarrier points of different OFDM symbols in the same slot are the same.
  • data signals are mapped in the order of the subcarriers and the OFDM symbols.
  • the subcarriers other than the scattered pilot and the continuation pilot in the effective subcarrier of each OFDM symbol are data subcarriers.
  • the continuous pilot, the scattered pilot, and the digital subcarrier of the system are reasonably set and allocated, so that the mobile multimedia broadcast transmitting system can reasonably set the system overhead and effectively use the spectrum resource to transmit data.
  • P c ⁇ i) ⁇ -[ ⁇ - 2S t ()) + (1 - 2S q ( ))] , where () and () are binary pseudo-random sequences (PRBS).
  • Figure 13 is a schematic diagram of a PRBS generation method.
  • the PRBS generator polynomial is: 2 + + + + ⁇ +1 , which corresponds to the illustrated shift register structure.
  • the initial value of the shift register is determined by the scrambling mode, and the corresponding relationship is as follows:
  • the PRBS is reset at the beginning of each time slot and all time slots are scrambled by the same pattern.
  • the scrambling code is implemented by complex multiplication of complex symbols and complex pseudo-random sequences on the effective subcarriers, the expression of which is:
  • JT is (0 is the ith effective subcarrier on the nth OFDM symbol of each slot before the scrambling code
  • ⁇ (0 is the effective subcarrier after scrambling.
  • FIG. 14 is a schematic diagram of a OFDM symbol subcarrier structure.
  • the OFDM effective subcarrier Q ⁇ ⁇ N S - 1 is mapped to the OFDM symbol by the IFT, and the mapping manner is:
  • ⁇ is the number of OFDM symbol subcarriers
  • Z n (i) is the IFT input signal of the nth OFDM symbol
  • (4 is the subcarrier spacing of the OFDM symbol, and the value is 2.44140625 kHz
  • ⁇ is the OFDM symbol cycle
  • the length of the prefix is 51.2 ⁇ , where ⁇ s is the length of the OFDM symbol, which is 460.8.
  • the number of OFDM symbol subcarriers N s 2048 , and the mapping relationship between the IFT input signal Z n () and the effective subcarrier of the OFDM frequency domain is:
  • the IFFT-transformed OFDM symbol is added to the cyclic prefix (CP) as shown in Fig. 7 to form a time domain OFDM symbol.
  • CP cyclic prefix
  • the modulated OFDM symbol sequentially adds a guard interval, a synchronization signal, and a transmitter identification signal to form a time slot. Then, 40 time slots are connected to form a physical layer signal frame.
  • the upper layer data stream of the system can use video streams including H.264, AVS, MPEG-2, MPEG-4, audio streams such as AC-3, AAC, and other data types of various data types.
  • Encoding data can include single media (eg video source encoding, text) and multimedia (audio, video) Various types of broadcast data within the mix of frequency, text and data).
  • each functional unit in each embodiment of the present invention may be integrated into one processing module, or each unit may exist physically separately, or two or more units may be integrated into one module.
  • the above integrated modules can be implemented in the form of hardware or in the form of software functional modules.
  • the integrated modules, if implemented in the form of software functional modules and sold or used as stand-alone products, may also be stored in a computer readable storage medium.
  • the above-mentioned storage medium may be a read only memory, a magnetic disk or an optical disk or the like.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Quality & Reliability (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Error Detection And Correction (AREA)

Abstract

A mobile multimedia broadcast transmission system is provided in the present invention, and includes: a Reed-Solomon (RS) coding and byte interleaving unit, a Low Density Parity Check (LDPC) coder, a bit interleaver, a constellation mapper, a frequency domain symbol generator, a scrambler, an Inverse Fast Fourier Transform (IFFT) converter, a time domain framer, and a transmitter. According to the technical schemes provided in the present invention, the system can provide mobile multimedia services of high quality for users in 5MHz operation bandwidth. Furthermore, optimization selections are performed on the RS coding according to the operation bandwidth of the system, thereby selecting an appropriate coding mode according to the different channel conditions, accordingly, optimization is performed on the byte interleaver, thereby using the reasonable interleaving parameters to perform byte interleaving. According to the actual bandwidth of the system, the technical schemes provided in the present invention reasonably set and allocate the continuous pilots, the scattered pilots and the data subcarriers of the system, and thereby enable that a mobile multimedia broadcast transmission system reasonably sets system overhead and effectively utilizes spectrum resources to transmit data.

Description

移动多媒体广播发送系统  Mobile multimedia broadcast transmission system
技术领域 本发明涉及数字信息传输技术领域， 特别涉及移动多媒体广播发送系 统。 背景技术 TECHNICAL FIELD The present invention relates to the field of digital information transmission technologies, and more particularly to a mobile multimedia broadcast transmission system. Background technique
目前无论是有线还是无线领域的通信服务， 多媒体业务都已经成为运 营商为客户提供的主要业务。 其中， 在无线通信领域中， 无线广播通信具 有覆盖面广、 节目容量大的特点， 其具有的最大优势就是具有广播性， 实 现一点对多点， 在低成本条件下具有较高传输带宽。 因此， 无线通信广播 作为信息通信业的一个重要组成部分， 在国家信息基础设施建设、 实现普 遍服务和国家信息安全战略中具有重要地位。  At present, whether it is a communication service in the wired or wireless field, multimedia services have become the main business provided by operators for customers. Among them, in the field of wireless communication, wireless broadcast communication has the characteristics of wide coverage and large program capacity, and its biggest advantage is that it has broadcastability, realizes point-to-multipoint, and has high transmission bandwidth under low-cost conditions. Therefore, as an important part of the information and communication industry, wireless communication broadcasting plays an important role in the construction of national information infrastructure, the realization of universal services and the national information security strategy.
在各种多媒体业务中， 其中移动多媒体广播业务目前被业界看作是一 种非常具有推广前景的重要应用。移动多媒体广播是指供七寸以下小屏幕、 小尺寸、 移动便携的手持终端如手机、 PDA, MP3、 MP4、 数码相机、 笔 记本电脑等接收设备， 随时随地接收广播电视节目和信息服务等业务的系 统。  Among various multimedia services, mobile multimedia broadcasting services are currently regarded by the industry as an important application with great promotion prospects. Mobile multimedia broadcasting refers to small-screen, small-sized, mobile and portable handheld terminals such as mobile phones, PDAs, MP3s, MP4s, digital cameras, laptops, etc., which can receive broadcast TV programs and information services anytime and anywhere. system.
目前在提供部分服务的移动多媒体广播都是基于现有移动通讯网络和 流媒体的， 然而， 由于现有移动通讯网络的带宽等技术特点决定了上述通 信方式不能对现有的移动多媒体广播性能作进一步的提升， 难以给用户提 供满意的收视体验。 考虑到广播技术和广播网络的优势， 一次传送无限接 收， 而且低成本、 高带宽， 因此利用广播网络和通讯网络的协作工作给手 持终端提供一种高质量的广播多媒体业务成为移动多媒广播研发的主要基 础。  At present, mobile multimedia broadcasting that provides some services is based on existing mobile communication networks and streaming media. However, due to the technical characteristics of the bandwidth of existing mobile communication networks, the above communication methods cannot be used for existing mobile multimedia broadcasting performance. Further improvement is difficult to provide users with a satisfactory viewing experience. Considering the advantages of broadcast technology and broadcast network, one-time transmission unlimited reception, and low cost and high bandwidth, the use of broadcast network and communication network cooperation work to provide a high-quality broadcast multimedia service for mobile terminals becomes mobile multimedia broadcast research and development. The main basis.
专门针对我国幅员辽阔、 传输环境复杂， 东部地区城市密集西部稀疏， 用户众多和业务需求多样化的国情， 申请人提出了一种釆用卫星广播覆盖 为主、 地面增补网络为辅的系统网络架构， 利用卫星覆盖面广、 建设周期 短、 见效快的特点， 实现低成本、 快速地实现移动多媒体广播信号在全国 的覆盖的技术方案， 并已经对相关的技术方案提交了申请发明专利的申请 文件， 具体见申请号为 200610113915.9、 200610113916.3 的申请文件。 在 上述公开的申请文件中， 提出了对移动多媒体广播釆用的具体技术方案， 包括移动多媒体广播物理层信道帧的结构、 信道编码和调制等技术方案。 Specifically for China's vast territory, complex transmission environment, dense urban sparseness in the eastern region, numerous users and diversified business needs, the applicant proposed a system network architecture based on satellite broadcasting coverage and supplemented by terrestrial supplementary networks. , using satellite coverage, construction period The short-term and quick-acting features enable low-cost and fast implementation of the coverage of mobile multimedia broadcast signals throughout the country, and have submitted application documents for applying for invention patents for related technical solutions. For details, see Application Nos. 200610113915.9, 200610113916.3 Application documents. In the above-mentioned published application file, a specific technical solution for mobile multimedia broadcast is proposed, including a technical scheme of a structure, channel coding and modulation of a mobile multimedia channel layer frame.
然而， 上述申请文件提出的技术方案通常为工作在 8M或 2M带宽内 的移动多媒体广播通信， 随着全球无线通信事业的快速发展， 无线电频率 资源的供需矛盾日益突出。 频率资源作为一种无线通信中必不可少的特殊 资源， 频率资源具有排他性和复用性， 即在一定的时间、 地区和频域内， 频率资源一旦被使用， 其他设备将不能再使用； 但在一定的时间、 地区、 频域和编码条件下， 无线电频率是可以复用和共用。 因此， 在全球各国频 率资源分配各不相同的情况下， 有必要提出一种适应于不同工作带宽的通 信系统。 发明内容  However, the technical solutions proposed in the above application documents are usually mobile multimedia broadcast communications operating within 8M or 2M bandwidth. With the rapid development of the global wireless communication industry, the contradiction between supply and demand of radio frequency resources has become increasingly prominent. As a special resource in wireless communication, frequency resources are exclusive and reusable. That is, in a certain time, region and frequency domain, once the frequency resources are used, other equipments can no longer be used; Radio frequencies are multiplexed and shared under certain time, region, frequency domain and coding conditions. Therefore, in the case of different frequency resource allocations in countries around the world, it is necessary to propose a communication system that adapts to different working bandwidths. Summary of the invention
本发明的目的旨在至少解决上述技术缺陷之一， 特别是解决移动多媒 体广播在不同的工作带宽内的发送问题。 本发明附加的方面和优点将在下 面的描述中部分给出， 部分将从下面的描述中变得明显， 或通过本发明的 实践了解到。  It is an object of the present invention to address at least one of the above-mentioned technical deficiencies, and in particular to solve the problem of transmission of mobile multimedia broadcasts within different operating bandwidths. The additional aspects and advantages of the invention will be set forth in part in the description which follows.
为达到上述目的， 本发明提出了一种移动多媒体广播发送系统， 包括： RS编码与字节交织器， 用于通过物理逻辑信道对上层数据流进行 RS 编码和字节交织； LDPC编码器， 用于对所述 RS编码与字节交织器输出的 数据进行 LDPC编码， 得到比特数据； 比特交织器， 用于对所述 LDPC编 码器输出的比特数据进行比特交织； 星座映射器， 用于对所述比特交织器 输出的数据进行星座映射； 频域符号生成器， 用于将离散导频、 包含有系 统信息的连续导频和经过星座映射的数据符号复接在一起组成 OFDM频域 变换器， 用于将所述扰码器输出的频域符号经过 IFFT 变换后产生 OFDM 时域符号； 时域组帧器， 用于将所述 OFDM时域符号组成时隙后， 连接组 成物理层信号帧； 发射器， 用于将所述物理层信号帧从基带信号变换至射 频后发射， 其中所述发射器使用无线信道内任意 5MHz带宽发射信号。 To achieve the above objective, the present invention provides a mobile multimedia broadcast transmitting system, comprising: an RS encoding and a byte interleaver for performing RS encoding and byte interleaving on an upper layer data stream through a physical logical channel; LDPC encoder, Performing LDPC encoding on the data output by the RS encoding and the byte interleaver to obtain bit data; a bit interleaver for performing bit interleaving on bit data output by the LDPC encoder; a constellation mapper for The data output by the bit interleaver performs constellation mapping; the frequency domain symbol generator is configured to multiplex the scattered pilot, the continuous pilot including the system information, and the data symbols mapped by the constellation to form an OFDM frequency domain converter, An OFDM time domain symbol is generated after the frequency domain symbol output by the scrambler is subjected to an IFFT transform; and a time domain framer is configured to form the OFDM time domain symbol into a time slot, and connect the group a physical layer signal frame; a transmitter, configured to transform the physical layer signal frame from a baseband signal to a radio frequency, wherein the transmitter transmits the signal using any 5 MHz bandwidth in the wireless channel.
根据本发明的实施例， 所述物理层信号帧长度为 1秒， 包括 40个长度 为 25毫秒的时隙， 所述时隙包括 1个信标和 53个 OFDM符号， 所述信标 包括 1个发射机标识信号和 2个相同的同步信号， 所述发射机标识信号由 频域随机序列依次进行 BPSK映射和 IFFT变换后再经过周期延拓而得到， 所述同步序列通过截取频域随机序列后，依次进行 BPSK和 IFFT变换而得 到。  According to an embodiment of the present invention, the physical layer signal frame length is 1 second, and includes 40 time slots having a length of 25 milliseconds, the time slot includes 1 beacon and 53 OFDM symbols, and the beacon includes 1 Transmitter identification signal and two identical synchronization signals, the transmitter identification signal is obtained by BPSK mapping and IFFT transformation in sequence by frequency domain random sequence, and then obtained by cyclic extension, and the synchronization sequence intercepts frequency domain random sequence Then, BPSK and IFFT are sequentially obtained and obtained.
根据本发明的实施例， 所述发射机标识信号通过 117 比特信息标识， 承载所述发射机标识信号的子载波数 ND=128, 通过 BPSK调制， 所述发射 机标识信号 σ(0由发射机标识序列 TxIDW映射产生， 映射方式为： XID(i) = 。According to an embodiment of the present invention, the transmitter identification signal is identified by 117-bit information, and the number of subcarriers carrying the transmitter identification signal is N D = 128, and the transmitter identification signal σ (0 is transmitted by BPSK modulation) The machine identification sequence TxIDW is generated by mapping: X ID (i) = .
Figure imgf000005_0001
Figure imgf000005_0001
根据本发明的实施例， 所述同步信号 (t )为频带受限的伪随机信号， 长度 ¾为 204.8^ ,  According to an embodiment of the invention, the synchronization signal (t) is a band-limited pseudo-random signal, and the length 3⁄4 is 204.8^.
Sh(t) = ≤t≤Tb, 其中 N¾为承载所述同步信号的子载
Figure imgf000005_0002
 S h (t) = ≤t≤T b , where N ¾ to carry the synchronization signal subcarriers
Figure imgf000005_0002
波数， 为承载二进制伪随机序列 ^^¾ )的 BPSK调制信号， （4\为同 步信号的子载波间隔， 子载波数^ =1024, 且 的 BPSK调制信号；^ () 由 映射产生， 映射方式为： Wavenumber , which is a BPSK modulated signal carrying a binary pseudo-random sequence ^^ 3⁄4 ), (4\ is the subcarrier spacing of the synchronization signal, the number of subcarriers is ^=1024, and the BPSK modulated signal; ^ () is generated by mapping, mapping mode for:
Xb(i) = 。X b (i) = .
Figure imgf000005_0003
Figure imgf000005_0003
根据本发明的实施例， 所述二进制伪随机序列由线性反馈移位寄存器 产生， 移位寄存器的初始值为 01110101101, 生成多项式为： x"+x9+l。 According to an embodiment of the invention, the binary pseudo-random sequence is generated by a linear feedback shift register, the initial value of the shift register is 01110101101, and the generator polynomial is: x"+x 9 +l.
根据本发明的实施例， 所述发射机标识、 同步序列和 OFDM符号间釆 用带窗函数的保护间隔相交叠， 所述窗函数的表达式为： w(t) = ，其中， t为时间变量，
Figure imgf000005_0004
According to an embodiment of the present invention, the guard identifier, the synchronization sequence, and the OFDM symbol overlap with a guard interval of a window function, and the expression of the window function is: w(t) = , where t is time variable,
Figure imgf000005_0004
T为常数， T™为所述保护间隔的长度。 根据本发明的实施例， 所述 RS编码是由原始的 RS ( 255, M) 系统码 通过截短后产生的 RS ( 192, K)截短码， 其中 M=K+63, K为一个码字中 信息序列的字节数，所述 RS( 255, M )系统码的每个码元取自域 GF( 256 ) , 该域的生成多项式为 PO) = JCS +JC4 + JC3 +JC2+1。 T is a constant and TTM is the length of the guard interval. According to an embodiment of the present invention, the RS code is an RS (192, K) truncation code generated by truncating the original RS (255, M) system code, where M=K+63, K is a code The number of bytes of the information sequence in the word. Each symbol of the RS ( 255, M ) system code is taken from the domain GF ( 256 ), and the generator polynomial of the domain is PO) = JC S + JC 4 + JC 3 + JC 2 +1.
根据本发明的实施例， 所述 RS ( 192, K)码包括 4种模式， 这 4种模 式中 K的取值分别为 K=192、 Κ=168、 Κ=160和 Κ=144。  According to an embodiment of the present invention, the RS (192, K) code includes four modes, and K values of the four modes are K = 192, Κ = 168, Κ = 160, and Κ = 144, respectively.
根据本发明的实施例， 所述 RS U92, Κ)码的生成多项式的表达式为 ； According to an embodiment of the present invention, the expression of the generator polynomial of the RS U92, Κ) code is;
Figure imgf000006_0001
Figure imgf000006_0001
当 K=192时， RS ( 192, 192) 的生成多项式表达式的系数 &为：
Figure imgf000006_0003
When K=192, the coefficient & of the generator polynomial expression of RS (192, 192) is:
Figure imgf000006_0003
当 K=168时， RS192, 168 ) 的生成多项式表达式的系数 &为:  When K=168, the coefficient & of the generator polynomial expression of RS192, 168) is:
Figure imgf000006_0004
Figure imgf000006_0004
当 K=160时， RS U92, 160 ) 的生成多项式表达式的系数 &为：  When K=160, the coefficient & of the generator polynomial expression of RS U92, 160 ) is:
Figure imgf000006_0005
Figure imgf000006_0005
Figure imgf000006_0002
4 113 17 170 30 21 43 195
Figure imgf000006_0002
4 113 17 170 30 21 43 195
5 204 18 150 31 161 44 2185 204 18 150 31 161 44 218
6 19 19 151 32 240 45 146 19 19 151 32 240 45 14
7 169 20 251 33 25 46 127 169 20 251 33 25 46 12
8 10 21 218 34 15 47 1228 10 21 218 34 15 47 122
9 244 22 245 35 71 48 19 244 22 245 35 71 48 1
10 117 23 166 36 62 10 117 23 166 36 62
11 219 24 149 37 5  11 219 24 149 37 5
12 130 25 183 38 17  12 130 25 183 38 17
根据本发明的实施例， 所述上层数据流以字节为单位， 从左至右逐列 输入 RS编码和字节交织器， 其中， RS编码按行进行编码， 字节交织器的 起始字节映射在某个时隙的起始点发送。  According to an embodiment of the present invention, the upper layer data stream is input into an RS code and a byte interleaver column by column from left to right in a byte unit, wherein the RS code is encoded in a row, and the start word of the byte interleaver The section map is sent at the beginning of a time slot.
根据本发明的实施例， 所述 LDPC编码后的输出块长为 9216比特， 码 率分别为 1/2和 3/4, 对应不同的码率， 所述字节交织器相应的交织模式分 别为：
Figure imgf000007_0001
According to an embodiment of the present invention, the output block length of the LDPC encoding is 9216 bits, and the code rates are 1/2 and 3/4, respectively, corresponding to different code rates, and the corresponding interleaving modes of the byte interleaver are respectively :
Figure imgf000007_0001
其中， MI为字节交织器的行数， 字节交织器中的全部字节为 Mix 192 字节。  Where MI is the number of lines of the byte interleaver, and all bytes in the byte interleaver are Mix 192 bytes.
根据本发明的实施例， 所述比特交织器釆用 384 x 216的块交织器； 从 LDPC 编码器输出的比特数据按照从上到下的顺序依次写入所述块交织器 的每一行， 直至填满整个块交织器， 再从左到右的按列依次读出， 其中比 特交织器的输出与时隙对齐。  According to an embodiment of the present invention, the bit interleaver uses a block interleaver of 384 x 216; bit data output from the LDPC encoder is sequentially written into each line of the block interleaver in order from top to bottom, until The entire block interleaver is filled, and then read out from left to right in columns, wherein the output of the bit interleaver is aligned with the time slot.
根据本发明的实施例，所述频域符号生成器在每个 OFDM符号中将 234 个离散导频、 76个连续导频、 1566个数据子载波复接在一起， 成为 1876 个有效子载波。  According to an embodiment of the invention, the frequency domain symbol generator multiplexes 234 discrete pilots, 76 consecutive pilots, and 1566 data subcarriers in each OFDM symbol into 1876 active subcarriers.
根据本发明的实施例， 所述 76个连续导频使用所述 1876个有效子载 波中第 0, 6, 66, 76, 92, 132, 150, 170, 206, 228, 260, 294, 296, 328, 338, 382, 392, 406, 462, 474, 480, 494, 552, 562, 582, 624, 630, 664, 668, 738, 744, 760, 790, 806, 834, 850, 922, 937, 938, 952, 1024, 1040, 1068, 1084, 1114, 1130, 1172, 1206, 1210, 1244, 1250, 1292, 1312, 1322, 1380, 1394, 1400, 1412, 1468, 1482, 1492, 1536, 1546, 1578, 1580, 1614, 1646, 1668, 1704, 1724, 1742, 1782, 1798, 1808, 1868, 1875个子载波， 并在其中第 6, 406, 1084, 1482, 66, 462, 1114, 1492, 76, 474, 1130, 1536, 92, 480, 1172, 1546, 132, 494, 1206, 1578, 150, 552, 1210, 1580, 170, 562, 1244, 1614, 206, 582, 1250, 1646, 228, 624, 1292, 1668, 260, 630, 1312, 1704, 294, 664, 1322, 1724, 296, 668, 1380, 1742, 328, 738, 1394, 1782, 338, 744, 1400, 1798, 382, 760, 1412, 1808, 392, 790, 1468, 1868共 64 个子载波中承载 16比特系统信息，所述系统信息包括长度为 6比特的时隙 号、 长度为 1 比特的字节交织器同步标识、 长度为 1 比特的控制逻辑信道 变更指示和长度为 8 比特的保留字； 所述连续导频以
Figure imgf000008_0001
,
Figure imgf000008_0002
的方式映射到子载波上， 其中， 同一时隙内不同 OFDM符 号的相同连续子载波点上传输的符号相同。 According to an embodiment of the present invention, the 76 consecutive pilots use 0, 6, 66, 76, 92, 132, 150, 170, 206, 228, 260, 294, 296 of the 1876 active subcarriers, 328, 338, 382, 392, 406, 462, 474, 480, 494, 552, 562, 582, 624, 630, 668, 738, 744, 760, 790, 806, 834, 850, 922, 937, 938, 952, 1024, 1040, 1068, 1084, 1114, 1130, 1172, 1206, 1210, 1244, 1250, 1292, 1312, 1322, 1380, 1394, 1400, 1412, 1468, 1482, 1492, 1536, 1546, 1578, 1580, 1614, 1646, 1668, 1704, 1724, 1742, 1782, 1798, 1808, 1868, 1875 subcarriers, and in the sixth, 406, 1084, 1482, 66, 462, 1114, 1492, 76, 474, 1130, 1536, 92, 480, 1172, 1546, 132, 494, 1206, 1578, 150, 552, 1210, 1580, 170, 562, 1244, 1614, 206, 582, 1250, 1646, 228, 624, 1292, 1668, 260, 630, 1312, 1704, 294, 664, 1322, 1724, 296, 668, 1380, 1742, 328, 738, 1394, 1782, 338, 744, 1400, 1798, 382, 760, 1412, 1808, 392, 790, 1468, 1868 A total of 64 subcarriers carrying 16 bits of system information, the system information a slot number of 6 bits in length, a byte interleaver synchronization identifier of 1 bit in length, a control logical channel change indication of length 1 bit, and a reserved word of 8 bits in length; the continuous pilot is
Figure imgf000008_0001
,
Figure imgf000008_0002
The manner is mapped to the subcarriers, wherein the symbols transmitted on the same consecutive subcarrier points of different OFDM symbols in the same slot are the same.
根据本发明的实施例，当每个时隙中 OFDM符号的编号为 n时， OFDM 符号中离散导频对应的子载波编号 m取值为：  According to an embodiment of the present invention, when the number of the OFDM symbol in each slot is n, the subcarrier number m corresponding to the scattered pilot in the OFDM symbol is:
当 mod(w,2) = 0 , , 禺散导频全邵取值为 1 + 0 。  When mod(w,2) = 0, the total pilot value of the scatter pilot is 1 + 0.
当
Figure imgf000008_0003
when
Figure imgf000008_0003
根据本发明的实施例，所述扰码器使用的伪随机序列的生成多项式为： χ12+χπ+χ8+χ6+ΐ; 所述扰码分为 8种模式， 对应的寄存器初始值分别为：According to an embodiment of the invention, the generator polynomial of the pseudo random sequence used by the scrambler is: χ 12 + χ π + χ 8 + χ 6 + ΐ; the scrambling code is divided into 8 modes, corresponding register initial The values are:
1 )扰码模式 0 初始值 0000 0000 0001, 1) Scrambling mode 0 initial value 0000 0000 0001,
2 )扰码模式 1 初始值 0000 1001 0011,  2) Scrambling mode 1 initial value 0000 1001 0011,
3 )扰码模式 2 初始值 0000 0100 1100,  3) Scrambling mode 2 initial value 0000 0100 1100,
4 )扰码模式 3 初始值 0010 1011 0011,  4) Scrambling mode 3 initial value 0010 1011 0011,
5 )扰码模式 4 初始值 0111 0100 0100,  5) Scrambling mode 4 Initial value 0111 0100 0100,
6 )扰码模式 5 初始值 0100 0100 1100,  6) Scrambling mode 5 initial value 0100 0100 1100,
7 )扰码模式 6 初始值 0001 0110 1101,  7) Scrambling mode 6 Initial value 0001 0110 1101,
8 )扰码模式 7 初始值 1010 1011 0011; 所述伪随机序列在每个时隙的开头重置，所有时隙都被相同图样扰码。 根据本发明的实施例 ,所述 IFFT变换器将 1876个有效子载波放在 2048 个子载波的第 1 ~ 938和第 1110 ~ 2047子载波上后进行 2048点 IFFT变换。 8) scrambling mode 7 initial value 1010 1011 0011; The pseudo-random sequence is reset at the beginning of each time slot, and all time slots are scrambled by the same pattern. According to an embodiment of the invention, the IFFT converter places 1876 effective subcarriers on the 1st to 938th and 11th to 20thth subcarriers of 2048 subcarriers and performs 2048 point IFFT conversion.
根据本发明的实施例， 所述时域组帧器将调制后的 OFDM符号依次加 入保护间隔、 同步信号、 发射机识别信号后组成时隙， 再将 40个时隙连接 组成物理层信号帧。  According to an embodiment of the present invention, the time domain framer sequentially adds the modulated OFDM symbols to the guard interval, the synchronization signal, and the transmitter identification signal to form a time slot, and then connects the 40 time slots to form a physical layer signal frame.
为了使移动多媒体广播发送系统能在不同的频率带宽内正常工作， 尤 其是 5MHz工作带宽内能为用户提供高质量的移动多媒体业务， 本发明根 据系统的技术特征， 对系统发射机标识信号、 同步信号进行合理设置， 使 其能为系统提供稳定的系统信息。此外，对 RS编码根据系统的工作带宽进 行优化选择， 根据不同的信道条件选择合适的编码模式， 相应地， 对字节 交织器进行优化， 使用合理的交织参数进行字节交织。 本发明提出的技术 方案， 根据系统的实际带宽， 合理设置、 分配系统的连续导频、 离散导频、 数字子载波， 使得移动多媒体广播发送系统合理设置系统开销， 有效利用 频谱资源传输数据。 附图说明  In order to enable the mobile multimedia broadcast transmission system to work normally in different frequency bandwidths, especially in the 5 MHz working bandwidth, the user can provide high quality mobile multimedia services. According to the technical features of the system, the system transmitter identification signals and synchronization are performed. The signal is properly set up to provide stable system information to the system. In addition, the RS code is optimized according to the operating bandwidth of the system, and the appropriate coding mode is selected according to different channel conditions. Accordingly, the byte interleaver is optimized, and byte interleaving is performed using reasonable interleaving parameters. According to the technical solution proposed by the present invention, according to the actual bandwidth of the system, the continuous pilot, the scattered pilot, and the digital subcarrier of the system are reasonably set and allocated, so that the mobile multimedia broadcast transmitting system appropriately sets the system overhead and effectively utilizes the spectrum resource to transmit data. DRAWINGS
本发明上述的和 /或附加的方面和优点从下面结合附图对实施例的描 述中将变得明显和容易理解， 其中：  The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from
图 1为本发明的移动多媒体广播发送系统的结构示意图；  1 is a schematic structural diagram of a mobile multimedia broadcast transmitting system according to the present invention;
图 2为本发明的移动多媒体广播发送系统的广播信道物理层逻辑信道 结构示意图  2 is a schematic structural diagram of a physical channel logical channel of a broadcast channel of a mobile multimedia broadcast transmitting system of the present invention;
图 3为本发明的移动多媒体广播发送系统物理层的逻辑信道编码和调 制流程图；  3 is a flow chart of logical channel coding and modulation of a physical layer of a mobile multimedia broadcast transmitting system according to the present invention;
图 4 为由时隙组帧所形成的物理层信号帧的时隙划分和帧结构示意 图；  4 is a schematic diagram of slot division and frame structure of a physical layer signal frame formed by slot grouping;
图 5为信标的结构示意图；  Figure 5 is a schematic structural diagram of a beacon;
图 6为同步信号的伪随机序列生成器结构示意图；  6 is a schematic structural diagram of a pseudo random sequence generator of a synchronization signal;
图 7为 OFDM符号的结构示意图； 图 8为保护间隔之间交叠的示意图； 7 is a schematic structural diagram of an OFDM symbol; Figure 8 is a schematic view showing the overlap between guard intervals;
图 9为 OFDM符号结构示意图；  9 is a schematic structural diagram of an OFDM symbol;
图 10为字节交织器与 RS ( 192 , K ) 编码的示意图；  Figure 10 is a schematic diagram of a byte interleaver and RS (192, K) coding;
图 11为对经过 LDPC编码后的比特流进行比特交织的示意图； 图 12为将 OFDM符号的子载波分配给数据符号、 离散导频和连续导 频的导频复接方式示意图；  11 is a schematic diagram of bit interleaving of an LDPC-encoded bit stream; FIG. 12 is a schematic diagram of a pilot multiplexing mode for allocating subcarriers of an OFDM symbol to data symbols, discrete pilots, and continuous pilots;
图 13为 PRBS生成方法的示意图；  Figure 13 is a schematic diagram of a PRBS generation method;
图 14为 OFDM符号子载波结构示意图。 具体实施方式  14 is a schematic diagram of a OFDM symbol subcarrier structure. detailed description
下面详细描述本发明的实施例， 所述实施例的示例在附图中示出， 其 中自始至终相同或类似的标号表示相同或类似的元件或具有相同或类似功 能的元件。 下面通过参考附图描述的实施例是示例性的， 仅用于解释本发 明， 而不能解释为对本发明的限制。  The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are intended to be illustrative only and not to be construed as limiting.
如图 1所示， 为本发明提出的移动多媒体广播发送系统， 包括： RS编 码与字节交织器、 LDPC 编码器、 比特交织器、 星座映射器、 频域符号生 成器、 扰码器、 IFFT变换器、 时域组帧器、 发射器。  As shown in FIG. 1 , the mobile multimedia broadcast transmitting system proposed by the present invention comprises: an RS encoding and a byte interleaver, an LDPC encoder, a bit interleaver, a constellation mapper, a frequency domain symbol generator, a scrambler, and an IFFT. Converter, time domain framer, transmitter.
其中， RS编码与字节交织器用于通过物理逻辑信道对上层数据流进行 RS编码和字节交织； LDPC编码器用于对 RS编码与字节交织器输出的数 据进行 LDPC编码， 得到比特数据； 比特交织器用于对 LDPC编码器输出 的比特数据进行比特交织； 星座映射器用于对比特交织器输出的数据进行 星座映射； 频域符号生成器用于将离散导频、 包含有系统信息的连续导频 和经过星座映射的数据符号复接在一起组成 OFDM频域符号； 扰码器用于 器输出的频域符号经过 IFFT变换后产生 OFDM时域符号； 时域组帧器， 用于将 OFDM时域符号组成时隙后， 连接组成物理层信号帧； 发射器用于 将所述物理层信号帧从基带信号变换至射频后发射， 其中发射器使用无线 信道内任意 5MHz带宽发射信号。  The RS encoding and the byte interleaver are configured to perform RS coding and byte interleaving on the upper layer data stream by using a physical logical channel; the LDPC encoder is configured to perform LDPC encoding on the data output by the RS encoding and the byte interleaver to obtain bit data; The interleaver is configured to perform bit interleaving on the bit data output by the LDPC encoder; the constellation mapper is configured to perform constellation mapping on the data output by the bit interleaver; the frequency domain symbol generator is configured to use the scattered pilot, the continuous pilot including the system information, and The data symbols of the constellation mapping are multiplexed together to form an OFDM frequency domain symbol; the frequency domain symbols used by the scrambler for the output of the device are subjected to IFFT transform to generate OFDM time domain symbols; and the time domain framing device is configured to compose OFDM time domain symbols After the time slot, the connection constitutes a physical layer signal frame; the transmitter is configured to transform the physical layer signal frame from the baseband signal to the radio frequency, and the transmitter transmits the signal using any 5 MHz bandwidth in the wireless channel.
利用本发明提出的移动多媒体广播发送系统， 可以向用户提供包括高 质量的数字音频广播、 数字视频广播在内的多媒体节目。 The mobile multimedia broadcast transmitting system proposed by the present invention can provide the user with high Multimedia programs such as digital audio broadcasting and digital video broadcasting.
本发明定义了每 5MHz频带内， 能对移动多媒体广播发送系统广播上 层数据流进行适配处理的物理层各功能模块， 给出了移动多媒体广播信道 物理层传输信号的帧结构、 信道编码、 调制技术。  The invention defines functional modules of the physical layer capable of adapting the upper layer data stream of the mobile multimedia broadcast transmission system in the 5 MHz frequency band, and gives the frame structure, channel coding and modulation of the physical layer transmission signal of the mobile multimedia broadcast channel. technology.
本发明定义的广播信道物理层通过物理层逻辑信道来适配上层各类应 用对传输速率的不同要求。 物理层逻辑信道支持多种编码和调制方式用以 满足不同应用、 不同传输环境对信号质量的不同要求。  The physical layer of the broadcast channel defined by the present invention adapts different requirements of the transmission rate of the various types of applications in the upper layer through the physical layer logical channel. The physical layer logical channel supports multiple encoding and modulation methods to meet the different signal quality requirements of different applications and different transmission environments.
本发明定义的广播信道物理层支持单频网和多频网两种组网模式， 可 根据实际应用的特性和组网环境选择不同的传输模式和参数。 支持多种应 用的混合模式， 达到应用特性与传输模式的匹配， 实现了应用的灵活性和 经济性。  The physical layer of the broadcast channel defined by the present invention supports two networking modes, a single frequency network and a multi-frequency network, and different transmission modes and parameters can be selected according to actual application characteristics and networking environment. A hybrid mode that supports multiple applications, matching application characteristics to transmission modes, and achieving application flexibility and economy.
如图 2所示， 为本发明的移动多媒体广播发送系统的广播信道物理层 逻辑信道结构示意图。  As shown in FIG. 2, it is a schematic diagram of a physical structure logical channel structure of a broadcast channel of a mobile multimedia broadcast transmitting system of the present invention.
物理层通过物理层逻辑信道（ Physical Logical Channel, 即 PLCH ) (包 括控制逻辑信道 CLCH和业务逻辑信道 SLCH )提供上层应用的广播通道。 每个物理层逻辑信道可以使用 5MHz数字电视带宽内的一个或多个时隙发 送。 物理层对每个物理层逻辑信道进行单独的编码和调制。 根据编码和调 制参数不同， 物理层逻辑信道可提供不同传输容量。  The physical layer provides a broadcast channel for the upper layer application through the Physical Logical Channel (PLCH), including the control logical channel CLCH and the service logical channel SLCH. Each physical layer logical channel can be transmitted using one or more time slots within a 5 MHz digital television bandwidth. The physical layer separately encodes and modulates each physical layer logical channel. Depending on the coding and modulation parameters, the physical layer logical channels can provide different transmission capacities.
图 3为本发明的移动多媒体广播发送系统物理层的逻辑信道编码和调 制流程图。  3 is a flow chart showing the logical channel coding and modulation of the physical layer of the mobile multimedia broadcast transmitting system of the present invention.
如图所示， 物理层逻辑信道的输入数据流经过前向纠错编码、 交织和 星座映射后， 与离散导频以及连续导频复接在一起进行 OFDM调制。 调制 后的信号经过插入帧头后形成物理层信号帧。 再经过基带至射频变换后进 行发射。  As shown in the figure, the input data stream of the physical layer logical channel is subjected to forward error correction coding, interleaving, and constellation mapping, and is multiplexed with the scattered pilot and the continuous pilot to perform OFDM modulation. The modulated signal forms a physical layer signal frame after being inserted into the frame header. It is then transmitted after baseband to RF conversion.
物理层逻辑信道分为控制逻辑信道（CLCH )和业务逻辑信道（ SLCH )。 控制逻辑信道用于承载系统配置信息， 釆用固定的信道编码和调制模型在 系统第 0时隙发送。  The physical layer logical channels are divided into a Control Logical Channel (CLCH) and a Service Logical Channel (SLCH). The control logical channel is used to carry system configuration information and is transmitted in the 0th time slot of the system using a fixed channel coding and modulation model.
图 4 为由时隙组帧所形成的物理层信号帧的时隙划分和帧结构示意 图。 如图所示， 系统物理层信号每 1 秒为 1 帧， 每帧划分为 40 个时隙 ( Timeslot, 即 TS ) , 各时隙的长度为 25MHzs。 每个时隙包括 1个信标和 53个 OFDM调制数据块。 FIG. 4 is a schematic diagram of slot division and frame structure of a physical layer signal frame formed by slot grouping. As shown in the figure, the system physical layer signal is 1 frame every 1 second, and each frame is divided into 40 time slots (Timelot, TS), and the length of each time slot is 25MHzs. Each slot includes 1 beacon and 53 OFDM modulated data blocks.
图 5为信标的结构示意图。 如图所示， 信标包括 2个相同的同步信号 以及发射机标识信号 （ID) 。  Figure 5 is a schematic diagram of the structure of the beacon. As shown, the beacon includes two identical sync signals and a transmitter identification signal (ID).
同步信号为频带受限的伪随机序列， 长度记为 , 取值为 204.8^。 同 步信号产生的公式为：  The synchronization signal is a band-limited pseudo-random sequence, and the length is recorded as , and the value is 204.8^. The formula generated by the sync signal is:
Shit) = 0≤t≤Tb, 其中， N¾为同步信号的子载波数，
Figure imgf000012_0001
S h it) = 0 ≤ t ≤ T b , where N 3⁄4 is the number of subcarriers of the synchronization signal,
Figure imgf000012_0001
为承载二进制伪随机序列 ^¾ )的 BPSK调制信号， （Δ/)¾为同步信号 的子载波间隔， 取值为 4.8828125kHz, 同步信号的子载波数 N¾ =1024。 Modulated carrier signal is BPSK binary pseudo-random sequence ^ ¾) a, (Δ /) ¾ subcarriers at intervals of the synchronization signal, a value of 4.8828125kHz, the number of subcarriers N ¾ = 1024 sync signal.
承载二进制序列伪随机 的 BPSK 调制信号；^ (0由 映射产 生， 映射方式为： 。 A pseudo-random BPSK modulated signal carrying a binary sequence; ^ (0 is generated by mapping, and the mapping method is: .
Figure imgf000012_0002
Figure imgf000012_0002
二进制伪随机序列 PN )由如图 6所示线性反馈移位寄存器产生，生成 多项式为： χ"+χ9+1。 移位寄存器初始值对每个同步信号均相同， 为The binary pseudo-random sequence PN is generated by a linear feedback shift register as shown in Figure 6. The generator polynomial is: χ"+χ 9 +1. The initial value of the shift register is the same for each sync signal.
01110101101。 01110101101.
发射机标识信号 D(t)为频带受限的伪随机信号，用于标识不同发射机。The transmitter identification signal D (t) is a band-limited pseudo-random signal used to identify different transmitters.
&D(t)长度记为 Tm , 取值为 36.0^。 发射机标识信号为： The length of & D (t) is denoted as T m and the value is 36.0^. The transmitter identification signal is:
SID (t) = o≤t≤TID, 其中， ND为发射机标识信
Figure imgf000012_0003
S ID (t) = o ≤ t ≤ T ID , where N D is the transmitter identification letter
Figure imgf000012_0003
号的子载波数， D(0为承载发射机标识序列的 BPSK调制信号， （A D为发 射机标识信号的子载波间隔， 取值为 39.0625kHz, JDcp为发射机标识信号 的循环前缀长度， 取值为 10.4^, 发射机标识信号的子载波数 ND =128。 Number of subcarriers, D (0 is the BPSK modulated signal carrying the transmitter identification sequence, (A D is the subcarrier spacing of the transmitter identification signal, and the value is 39.0625 kHz, J Dcp is the cyclic prefix length of the transmitter identification signal) , the value is 10.4^, and the number of subcarriers of the transmitter identification signal is N D =128.
承载发射机标识序列的 BPSK调制信号 XID{P>由发射机标识序列 TxIDil) 映射产生， 映射方式为： The BPSK modulated signal X ID {P> carrying the transmitter identification sequence is generated by mapping the transmitter identification sequence TxIDil. The mapping manner is:
\-2xTxID(i-\\ 1</<58  \-2xTxID(i-\\ 1</<58
0, = 0或 59≤ ≤ 68  0, = 0 or 59 ≤ ≤ 68
\-2xTxID(i-n\ 69</<127 上述发射机标识序列 Γχ/Ζ) )是长度为 117 比特的伪随机序列。 发射机 标识序列共包括 256个序列， 其中序列 0〜序列 127为地区标识， 用于标 识发射机所在的地区， 其插入信号帧中的偶数时隙发送： 第 0 时隙， 第 2 时隙， ... ...； 序列 128 ~ 255为发射机标识， 用于标识同一地区内的不同发 射机， 其插入信号帧中的奇数时隙发送： 第 1 时隙， 第 3时隙， ... ...。 发 射机标识序列由十六进制序列定义， 该十六进制序列按照最高有效比特在 先的顺序映射为二进制发射机标识序列。 \-2xTxID(in\ 69</<127 The above transmitter identification sequence Γχ/Ζ)) is a pseudo-random sequence of length 117 bits. The transmitter identification sequence includes a total of 256 sequences, wherein the sequence 0 to sequence 127 are area identifiers, which are used to identify the region where the transmitter is located, and the even time slots in the inserted signal frame are transmitted: the 0th time slot, the 2nd time slot, ...;; Sequences 128 ~ 255 are transmitter identifiers used to identify different transmitters in the same area, which are transmitted in odd time slots in the inserted signal frame: 1st time slot, 3rd time slot, .. . . . The transmitter identification sequence is defined by a hexadecimal sequence that maps to the binary transmitter identification sequence in the order of the most significant bits.
为了使移动多媒体广播发送系统能在不同的频率带宽内正常工作， 尤 其是 5MHz工作带宽内能为用户提供高质量的移动多媒体业务， 上述技术 方案根据系统的技术特征， 对系统发射机标识信号、 同步信号进行合理设 置， 使其能为系统提供稳定的系统信息。  In order to enable the mobile multimedia broadcast transmission system to work normally in different frequency bandwidths, especially in the 5 MHz working bandwidth, the user can provide high quality mobile multimedia services, and the above technical solutions are based on the technical characteristics of the system, and the system transmitter identification signals, The synchronization signal is properly set up to provide stable system information to the system.
如图 7所示，为 OFDM符号的结构示意图。 OFDM符号由循环前缀（ CP ) 和 OFDM符号体构成， 循环前缀长度 TCP为 51.2us , 即 IFFT后的 256个 釆样点， OFDM符号长度 TS为 409.6us, 即 IFFT后的 2048个釆样点。  As shown in FIG. 7, it is a schematic structural diagram of an OFDM symbol. The OFDM symbol is composed of a cyclic prefix (CP) and an OFDM symbol body. The cyclic prefix length TCP is 51.2us, that is, 256 samples after the IFFT, and the OFDM symbol length TS is 409.6us, that is, 2048 samples after the IFFT.
发射机标识信号、同步信号和相邻 OFDM符号之间通过保护间隔（ GD ) 相互交叠， 保护间隔 GD的长度 TGD为 2.4us , 即 IFFT后的 12个釆样点。 相邻符号之间， 前一个符号的尾部 GD与后一个符号的头部 GD经过窗函 数加权后叠加， 如图 8所示。  The transmitter identification signal, the synchronization signal and the adjacent OFDM symbols overlap each other by a guard interval (GD), and the guard interval GD has a length TGD of 2.4 us, that is, 12 samples after the IFFT. Between adjacent symbols, the tail GD of the previous symbol and the head GD of the latter symbol are weighted by the window function and superimposed as shown in Fig. 8.
所述的窗函数表达式为：  The window function expression is:
0.5 + 0.5 cos(^ + ^t/ 7GD), 0≤t≤TGD 0.5 + 0.5 cos(^ + ^t/ 7 GD ), 0≤t≤T GD
1, TGD < t < T+ TGD ，其中， t为时间变量，1, T GD < t < T+ T GD , where t is a time variable,
0.5 + 0.5 cosOr + π(Τ -t) /TGD), T+ TGD≤t≤T+ 2TGD 0.5 + 0.5 cosOr + π(Τ -t) /T GD ), T+ T GD ≤t≤T+ 2T GD
T为常数， 为所述保护间隔的长度。  T is a constant and is the length of the guard interval.
保护间隔信号的选取如图 9所示。 对于发射机标识信号， 同步信号和 OFDM符号， T0和 T1部分的取值见表 1 , τ = το + η。  The selection of the guard interval signal is shown in Figure 9. For the transmitter identification signal, the synchronization signal and the OFDM symbol, the values of the T0 and T1 parts are shown in Table 1, τ = το + η.
Figure imgf000013_0001
Figure imgf000013_0001
表 1、 保护间隔信号取值表  Table 1. Protection interval signal value table
如图 10所示， 为字节交织器与 RS ( 192 , K ) 编码的示意图 字节交织器为 MI行、 192列的块交织器。 字节交织器的行数 Ml由字 节交织模式和 LDPC码率决定， 如表 2所示：
Figure imgf000014_0002
As shown in Figure 10, a schematic diagram of the byte interleaver and RS (192, K) coding The byte interleaver is a block interleaver of MI rows and 192 columns. The number of lines M1 of the byte interleaver is determined by the byte interleave mode and the LDPC code rate, as shown in Table 2:
Figure imgf000014_0002
表 2、 字节交织器参数 MI的取值表  Table 2. Byte interleaver parameters MI value table
RS码釆用码长为 192字节的 RS ( 192,K) 截短码。 该码由原始的 RS ( 255,Μ) 系统码通过截短产生，其中 Μ=Κ+63。 Κ 为一个码字中信息序列 的字节数， 校验字节数为 （192-K) 。 RS ( 192,Κ)码提供 4种模式， 分 别为 Κ=192、 Κ=168、 Κ=160、 Κ=144。  The RS code uses an RS (192, K) truncation code with a code length of 192 bytes. This code is generated by truncation of the original RS (255, Μ) system code, where Μ = Κ + 63. Κ is the number of bytes of the information sequence in a codeword, and the number of check bytes is (192-K). The RS (192, Κ) code provides four modes, Κ=192, Κ=168, Κ=160, Κ=144.
RS 码的每个码元取自 域 GF ( 256 ) , 其域生成多 项式为 p(x) = JC8 + JC4 + JC3 + JC2 + 1。 Each symbol of the RS code is taken from the domain GF (256) whose domain generator polynomial is p(x) = JC 8 + JC 4 + JC 3 + JC 2 + 1.
截短码 RS ( 192,K) 釆用如下方式进行编码： 在 Κ 个输入信息字节 前添加 63个全 "0" 字节， 构造为原始的 RS ( 255,Μ) 系统 码 的 输 入 序 歹' J (0,0,--·,0,τη0,ηιλ,---,ηικ_λ) , 编 码 后 生 成 码 字 (0,0,··· A m0,mf ,υ0, ρ255—Μ— , 再从码字中删去添加的字节， 即得到 192字节的截短 RS码的码字为 (mo'mf'm Po'pd M— 。 The truncation code RS (192, K) is encoded as follows: Add 63 all "0" bytes before the 输入 input information bytes, and construct the input sequence of the original RS (255, Μ) system code. ' J (0,0,--·,0,τη 0 ,ηι λ ,---,ηι κ _ λ ) , generates a codeword after encoding (0,0,··· A m 0 ,mf ,υ 0 , ρ 255 — Μ — , and then add the added bytes from the codeword, that is, the codeword of the 192-byte truncated RS code is (mo'mf'm Po'pd M- .
RS ( 192,K)码的生成多项式表示为：  The generator polynomial of the RS (192, K) code is expressed as:
； ;
Figure imgf000014_0001
Figure imgf000014_0001
输入信息序列多项式为：  The input information sequence polynomial is:
m(x) = jmlx1； 输出的系统码多项式为： m(x) = j m l x 1 ; The system code polynomial of the output is:
C(x) = yClx' = xl92-Km{x) + r{x)； 其中， r(x) = ^ ~~ ^。 C(x) = y Cl x' = x l92 - K m{x) + r{x); where r(x) = ^ ~~ ^.
!=。 gO)  !=. gO)
当 K=192时， RS ( 192, 192) 的生成多项式表达式的系数 &为：
Figure imgf000014_0003
When K=192, the coefficient & of the generator polynomial expression of RS (192, 192) is:
Figure imgf000014_0003
当 K=168时， RS192, 168 ) 的生成多项式表达式的系数 &为:
Figure imgf000014_0004
2 199 9 125 16 218 23 244When K=168, the coefficient & of the generator polynomial expression of RS192, 168) is:
Figure imgf000014_0004
2 199 9 125 16 218 23 244
3 208 10 44 17 8 24 13 208 10 44 17 8 24 1
4 173 11 167 18 197 4 173 11 167 18 197
5 79 12 198 19 195  5 79 12 198 19 195
6 45 13 150 20 20  6 45 13 150 20 20
当 K=160时， RS U92, 160 ) 的生成多项式表达式的系数 &为：  When K=160, the coefficient & of the generator polynomial expression of RS U92, 160 ) is:
Figure imgf000015_0001
Figure imgf000015_0001
当 K=144时， RS ( 192, 144 ) 的生成多项式表达式的系数 &为：  When K=144, the coefficient & of the generator polynomial expression of RS (192, 144) is:
Figure imgf000015_0002
Figure imgf000015_0002
编码和字节交织的方法如下： 传输数据块以字节为单位， 从左至右逐 列输入块交织器，每列 Ml字节， 直到第 K列完成。 RS编码按行进行编码， 校验字节填充至后的 192-K列。 编码后的数据再按照输入的顺序从左至右 逐列输出， 直到 192列全部完成。  The method of encoding and byte interleaving is as follows: The data block is transferred in bytes, from left to right, into the block interleaver, M1 bytes per column, until the Kth column is completed. The RS code is encoded in rows, and the check byte is padded to the next 192-K column. The encoded data is output column by column from left to right in the order of input until the 192 columns are all completed.
上述 RS编码和字节交织以物理逻辑信道为单位进行，相同物理逻辑信 道的上层数据包依次输入字节交织器进行字节交织和 RS编码。字节交织器 第 0列的第一个字节定义为字节交织器的起始字节。 字节交织器每次的输 出 Mi x 192字节总是映射在整数个时隙上发送， 其中字节交织器的起始字 节映射在某个时隙的起始点发送。 The above RS coding and byte interleaving are performed in units of physical logical channels, and upper layer data packets of the same physical logical channel are sequentially input into a byte interleaver for byte interleaving and RS coding. The first byte of column 0 of the byte interleaver is defined as the starting byte of the byte interleaver. The output of the byte interleaver each time Mi x 192 bytes is always mapped on an integer number of time slots, where the start word of the byte interleaver The section map is sent at the beginning of a time slot.
通过上述技术方案，对 RS编码根据系统的工作带宽进行优化选择，根 据不同的信道条件选择合适的编码模式， 相应地， 对字节交织器进行优化， 使用合理的交织参数进行字节交织。  Through the above technical solution, the RS coding is optimized according to the working bandwidth of the system, and the appropriate coding mode is selected according to different channel conditions. Accordingly, the byte interleaver is optimized, and the byte interleaving is performed using reasonable interleaving parameters.
经过上述 RS 编码和字节交织后的传输数据按照高位比特优先发送的 原则， 将每字节映射为 8位比特流， 送入 LDPC编码器。 字节交织器第 0 列的第一个字节定义为字节交织器的起始字节，其最高位总是映射在 LDPC 输入比特块的第一个比特。 LDPC编码配置如表 3所示：  The above-mentioned RS coded and byte-interleaved transmission data is mapped to an 8-bit bit stream and sent to the LDPC encoder according to the principle of high-order bit priority transmission. The first byte of column 0 of the byte interleaver is defined as the start byte of the byte interleaver whose highest bit is always mapped to the first bit of the LDPC input block. The LDPC encoding configuration is shown in Table 3:
Figure imgf000016_0002
Figure imgf000016_0002
表 3、 LDPC编码配置  Table 3. LDPC encoding configuration
LDPC编码由校验矩阵 H给出， H矩阵的生成方法如下:  The LDPC code is given by the check matrix H, and the H matrix is generated as follows:
1 ) 丄 LDPC码校验矩阵生成方法  1) 生成 LDPC code check matrix generation method
Figure imgf000016_0001
Figure imgf000017_0001
Figure imgf000016_0001
Figure imgf000017_0001
以下为生成丄 LDPC码校验矩阵的循环程序段：  The following is the loop block for generating the 丄 LDPC code check matrix:
2  2
for 1=1:18;  For 1=1:18;
取上表第 I行， 记为 hexp;  Take the first line of the table and record it as hexp;
for J=l:256;  For J=l:256;
丽= ( J-l ) *18+I;  丽 = ( J-l ) *18+I;
for K=l:6;  For K=l:6;
column = ([hexp(K) / 36」 + J - 1) %256] * 36 + (hexp(K)%36) + 1 奇偶校验矩阵的第 row行、 第 column列为非 0元素 end;  Column = ([hexp(K) / 36" + J - 1) %256] * 36 + (hexp(K)%36) + 1 The first row of the parity check matrix, the column of the column is a non-zero element end;
end;  End;
end;  End;
2) ^LDPC码校验矩阵生成方法  2) ^LDPC code check matrix generation method
4  4
Figure imgf000017_0002
Figure imgf000017_0002
以下为生成 LDPC码校验矩阵的循环程序段：  The following is the loop block for generating the LDPC code check matrix:
4  4
for 1=1:9;  For 1=1:9;
取上表第 I行， 记为 hexp;  Take the first line of the table and record it as hexp;
for J=l:256;  For J=l:256;
丽= (J-l ) *9+I;  丽 = (J-l) *9+I;
for K=l:12;  For K=l:12;
column = ([hexp(K) / 36」 + J - 1) %256] * 36 + (hexp(K)%36) + 1 奇偶校验矩阵的第 row行第 column列为非 0元素 end; end; Column = ([hexp(K) / 36" + J - 1) %256] * 36 + (hexp(K)%36) + 1 The first column of the parity matrix is the non-zero element end; End;
erid。  Erid.
如图 11所示，为对经过 LDPC编码后的比特流进行比特交织的示意图。 比特交织器釆用 384 x 216的块交织器。 LDPC编码后的二进制序列按 照从上到下的顺序依次写入块交织器的每一行， 直至填满整个交织器， 再 从左到右的按列依次读出。 比特交织器的输出与时隙对齐， 即， 每个时隙 中传送的第一个比特总定义为比特交织器输出的第一个比特。  As shown in FIG. 11, it is a schematic diagram of bit interleaving of an LDPC-encoded bit stream. The bit interleaver uses a 384 x 216 block interleaver. The LDPC-encoded binary sequence is sequentially written to each line of the block interleaver in order from top to bottom until the entire interleaver is filled, and then read from left to right in columns. The output of the bit interleaver is aligned with the time slot, i.e., the first bit transmitted in each time slot is always defined as the first bit of the bit interleaver output.
图 12为将 OFDM符号的子载波分配给数据符号、 离散导频和连续导 频的导频复接方式示意图。 其中， 斜线部分为连续导频信号， 黑色部分为 离散导频信号， 白色部分为经星座映射得到的数据符号。 图示的导频复接 将数据符号、 离散导频和连续导频复接在一起， 组成 OFDM频域符号。 每 个 OFDM符号包括 1876个子载波（ 0 - 1875 ) , 记为 JT()， = 0,1,···1875 , 其中包括 234个离散导频、 76个连续导频、 1566个数据子载波。  12 is a schematic diagram of a pilot multiplexing manner of allocating subcarriers of an OFDM symbol to data symbols, discrete pilots, and continuous pilots. Wherein, the oblique line part is a continuous pilot signal, the black part is a discrete pilot signal, and the white part is a data symbol obtained by constellation mapping. The illustrated pilot multiplexing multiplexes the data symbols, the scattered pilots, and the continual pilots to form an OFDM frequency domain symbol. Each OFDM symbol includes 1876 subcarriers (0 - 1875), denoted as JT(), = 0,1,···1875, which includes 234 discrete pilots, 76 consecutive pilots, and 1566 data subcarriers.
图 12中， 连续导频使用第 0, 6, 66, 76, 92, 132, 150, 170, 206, 2 22288,, 2266U0,, 229944,, 229966,, 332288,, 333388,, 382, 392, 406, 462, 474, 480, 494, 552, 562, 582, 624, 630, 664, 668, 738, 744, 760, 790, 806, 834, 850, 922, 937, 938, 952, 1024, 1040, 1068, 1084, 1114, 1130, 1172, 1206, 1210, 1244, 1250, 1292, 1312, 1322, 1380, 1394, 1400, 1412, 1468, 1482, 1492, 1536, 1546, 1578, 1580, 1614, 1646, 1668, 1704, 11772244,, 11774422,, 11778822,, 11779988,, 11丽808，, 1868, 1875个子载波， 共 76个。  In Figure 12, the continuous pilot uses 0, 6, 66, 76, 92, 132, 150, 170, 206, 2 22288, 2266U0, 229944, 229966, 332288, 333388, 382, 392, 406, 462, 474, 480, 494, 552, 562, 582, 624, 630, 668, 738, 744, 760, 790, 806, 834, 850, 922, 937, 938, 952, 1024, 1040, 1068, 1084, 1114, 1130, 1172, 1206, 1210, 1244, 1250, 1292, 1312, 1322, 1380, 1394, 1400, 1412, 1468, 1482, 1492, 1536, 1546, 1578, 1580, 1614, 1646, 1668, 1704, 11772244,, 11774422, 11778822,, 11779988, 11 808, 1868, 1875 subcarriers, a total of 76.
其中第 6, 406, 1084, 1482, 66, 462, 1114, 1492, 76, 474, 1130, 1536, 92, 480, 1172, 1546, 132, 494, 1206, 1578, 150, 552, 1210, 1580, 170, 562, 1244, 1614, 206, 582, 1250, 1646, 228, 624, 1292, 1668, 260, 630, 1312, 1704, 294, 664, 1322, 1724, 296, 668, 1380, 1742, 328, 738, 1394, 1782, 338, 744, 1400, 1798, 382, 760, 1412, 1808, 392, 790, 1468, 1868共 64个载波承载 16比特系统信息。 系统信 息比特釆用 4倍重复编码映射在 4个连续导频上传送， 映射关系如表 4所 示， 系统信息具体表述如表 5所示。 其余连续导频传输 "0" 。 比特 釆用子载波编号 Wherein, 6, 406, 1084, 1482, 66, 462, 1114, 1492, 76, 474, 1130, 1536, 92, 480, 1172, 1546, 132, 494, 1206, 1578, 150, 552, 1210, 1580, 170, 562, 1244, 1614, 206, 582, 1250, 1646, 228, 624, 1292, 1668, 260, 630, 1312, 1704, 294, 664, 1322, 1724, 296, 668, 1380, 1742, 328, 738, 1394, 1782, 338, 744, 1400, 1798, 382, 760, 1412, 1808, 392, 790, 1468, 1868 A total of 64 carriers carry 16-bit system information. The system information bits are transmitted on four consecutive pilots using a 4-fold repetition coding mapping. The mapping relationship is shown in Table 4, and the system information is specifically shown in Table 5. The remaining consecutive pilots transmit "0". Bit 釆 subcarrier number
0 6、 406、 1084、 1482  0 6, 406, 1084, 1482
1 66、 462、 1114、 1492  1 66, 462, 1114, 1492
2 76、 474、 1130、 1536  2 76, 474, 1130, 1536
3 92、 480、 1172、 1546  3 92, 480, 1172, 1546
4 132、 494、 1206、 1578  4 132, 494, 1206, 1578
5 150、 552、 1210、 1580  5 150, 552, 1210, 1580
6 170、 562、 1244、 1614  6 170, 562, 1244, 1614
7 206、 582、 1250、 1646  7 206, 582, 1250, 1646
8 228、 624、 1292、 1668  8 228, 624, 1292, 1668
9 260、 630、 1312、 1704  9 260, 630, 1312, 1704
10 294、 664、 1322、 1724  10 294, 664, 1322, 1724
11 296、 668、 1380、 1742  11 296, 668, 1380, 1742
12 328、 738、 1394、 1782  12 328, 738, 1394, 1782
13 338、 744、 1400、 1798  13 338, 744, 1400, 1798
14 382、 760、 1412、 1808  14 382, 760, 1412, 1808
15 392、 790、 1468、 1868  15 392, 790, 1468, 1868
表 4、 连续导频上的重复编码方式  Table 4. Repeated coding methods on continuous pilots
Figure imgf000019_0002
Figure imgf000019_0002
表 5、 连续导频传输的系统信息  Table 5. System information for continuous pilot transmission
表 5中各比特具体所包含信息内容如下：  The information contained in each bit in Table 5 is as follows:
1 ) bit0~bit5为当前时隙号， 取值范围 0~ 39;  1) bit0~bit5 are the current slot number, ranging from 0~39;
2) bit6为字节交织器同步标识， 该比特取值为 1时标识本时隙为字节 交织器起始时隙；  2) bit 6 is a byte interleaver synchronization identifier. When the bit is 1, the time slot is identified as a byte interleaver start time slot;
3) bit7为控制逻辑信道变更指示， 其釆用差分调制的方式指示终端控 制逻辑信道配置信息变更。 所述差分方式如下： 假设上一帧 bit7传送的是 a, 0或者 1, 而系统控制信道配置信息将在下一帧发生变更， 则在本帧中 传送 并保持下去， 直到发生下次变更。  3) bit 7 is a control logical channel change indication, which instructs the terminal to control the logical channel configuration information change by means of differential modulation. The difference mode is as follows: Assume that the previous frame bit7 transmits a, 0 or 1, and the system control channel configuration information will be changed in the next frame, then it is transmitted and held in this frame until the next change occurs.
4) bit8~bitl5保留。  4) bit8~bitl5 is reserved.
连续导频以 0→ /2 +
Figure imgf000019_0001
-V2/2-72/2 j的方式映射到子载波上。 同一时隙内不同 OFDM符号的相同连续子载波点上传输的符号相同。 Continuous pilot with 0→ /2 +
Figure imgf000019_0001
The -V2/2-72/2 j mode is mapped to the subcarriers. The symbols transmitted on the same consecutive subcarrier points of different OFDM symbols in the same slot are the same.
记 n为每个时隙中 OFDM符号的编号， 0≤«≤52； m为每个 OFDM符 号中离散导频对应的子载波编号， 则 m取值如下：  Let n be the number of the OFDM symbol in each slot, 0 ≤ « ≤ 52; m is the subcarrier number corresponding to the discrete pilot in each OFDM symbol, then m is as follows:
当 mod(w,2) = 0  When mod(w,2) = 0
Figure imgf000020_0001
Figure imgf000020_0001
图 12中，按子载波、 OFDM符号的前后顺序映射数据信号。每个 OFDM 符号的有效子载波中除离散导频和连续导频外的子载波为数据子载波。 每 个时隙中共有 82998个数据子载波， 其中前 82944个数据子载波用于承载 星座映射后的数据符号， 最后 54个数据子载波填充 0 + 0j。  In Fig. 12, data signals are mapped in the order of the subcarriers and the OFDM symbols. The subcarriers other than the scattered pilot and the continuation pilot in the effective subcarrier of each OFDM symbol are data subcarriers. There are 82,998 data subcarriers in each time slot, of which the first 82,944 data subcarriers are used to carry the constellation mapped data symbols, and the last 54 data subcarriers are filled with 0 + 0j.
本发明提出的上述技术方案， 根据系统的实际带宽， 合理设置、 分配 系统的连续导频、 离散导频、 数字子载波， 使得移动多媒体广播发送系统 合理设置系统开销， 有效利用频谱资源传输数据。  According to the above technical solution proposed by the present invention, according to the actual bandwidth of the system, the continuous pilot, the scattered pilot, and the digital subcarrier of the system are reasonably set and allocated, so that the mobile multimedia broadcast transmitting system can reasonably set the system overhead and effectively use the spectrum resource to transmit data.
图 12所示时频格栅上的所有符号 （有效子载波） ， 包括数据子载波、 离散导频和连续导频等， 均被一个复伪随机序列 扰码。 所述复伪随机 序列 PC( )的生成方式如下： All symbols (effective subcarriers) on the time-frequency grid shown in Figure 12, including data subcarriers, scattered pilots, and continual pilots, are scrambled by a complex pseudo-random sequence. The pseudo-random random sequence P C ( ) is generated as follows:
Pc{i) = ^-[{\- 2St ()) + (1 - 2Sq ( ))] , 其中， ()和 ()为二进制伪随机序列 （PRBS) 。 P c {i) = ^-[{\- 2S t ()) + (1 - 2S q ( ))] , where () and () are binary pseudo-random sequences (PRBS).
图 13为 PRBS生成方法的示意图。  Figure 13 is a schematic diagram of a PRBS generation method.
如图所示， PRBS的生成多项式为： 2+ + + ^+1 , 与图示的移位寄 存器结构相对应。 移位寄存器的初始值由扰码模式确定， 其对应关系如下：As shown, the PRBS generator polynomial is: 2 + + + ^+1 , which corresponds to the illustrated shift register structure. The initial value of the shift register is determined by the scrambling mode, and the corresponding relationship is as follows:
1 )扰码模式 0 初始值 000000000001 1) Scrambling mode 0 Initial value 000000000001
2 )扰码模式 1 初始值 000010010011  2) Scrambling mode 1 Initial value 000010010011
3 )扰码模式 2 初始值 000001001100  3) Scrambling mode 2 Initial value 000001001100
4 )扰码模式 3 初始值 001010110011  4) Scrambling mode 3 Initial value 001010110011
5 )扰码模式 4 初始值 011101000100  5) Scrambling mode 4 Initial value 011101000100
6 )扰码模式 5 初始值 010001001100 7 )扰码模式 6: 初始值 000101101101; 6) Scrambling mode 5 initial value 010001001100 7) scrambling code mode 6: initial value 000101101101;
8)扰码模式 7: 初始值 101010110011。  8) Scrambling mode 7: Initial value 101010110011.
PRBS在每个时隙开头重置， 所有时隙都被相同图样扰码。  The PRBS is reset at the beginning of each time slot and all time slots are scrambled by the same pattern.
该扰码通过将有效子载波上的复符号和复伪随机序列 进行复数乘 法而实现， 所述扰码的表达式为：  The scrambling code is implemented by complex multiplication of complex symbols and complex pseudo-random sequences on the effective subcarriers, the expression of which is:
Yn (/) = Χη (/) χ c (« χ 1876 + /), 0</<1875,0<«<52 Y n (/) = Χ η (/) χ c (« χ 1876 + /), 0</<1875, 0<«<52
其中， JT„(0为扰码前每个时隙第 n个 OFDM符号上的第 i个有效子载 波， ί (0为扰码后的有效子载波。  Where JT is (0 is the ith effective subcarrier on the nth OFDM symbol of each slot before the scrambling code, ί (0 is the effective subcarrier after scrambling.
图 14为 OFDM符号子载波结构示意图。  14 is a schematic diagram of a OFDM symbol subcarrier structure.
上述插入导频并加扰后 OFDM有效子载波 Q≤ ≤NS- 1通过 IFT映 射为 OFDM符号， 映射方式为： After the above pilot is inserted and scrambled, the OFDM effective subcarrier Q ≤ ≤ N S - 1 is mapped to the OFDM symbol by the IFT, and the mapping manner is:
Ns-\ N s -\
Sn (t) = -j= Τ Zn {ί)β ί2πί^ 0≤t≤Ts,0≤n≤52 , 其中， (t)为时隙中第 S n (t) = -j= Τ Z n {ί) β ί2πί ^ 0 ≤ t ≤ T s , 0 ≤ n ≤ 52 , where (t) is the time slot
,=。  ,=.
n个 OFDM符号， ^为 OFDM符号子载波数， Zn(i)为第 n个 OFDM符号 的 IFT输入信号，（4 为 OFDM符号的子载波间隔，取值为 2.44140625kHz, ^为 OFDM符号循环前缀长度， 取值为 51.2^, Γs为 OFDM符号长度， 取值为 460.8 。 n OFDM symbols, ^ is the number of OFDM symbol subcarriers, Z n (i) is the IFT input signal of the nth OFDM symbol, (4 is the subcarrier spacing of the OFDM symbol, and the value is 2.44140625 kHz, ^ is the OFDM symbol cycle The length of the prefix is 51.2^, where Γ s is the length of the OFDM symbol, which is 460.8.
OFDM符号子载波数 Ns = 2048 , IFT输入信号 Zn ()与 OFDM频域有效 子载波 ί^Ο的映射关系为： The number of OFDM symbol subcarriers N s = 2048 , and the mapping relationship between the IFT input signal Z n () and the effective subcarrier of the OFDM frequency domain is:
Yn{i-\ 1</<938 Y n {i-\ 1</<938
Zn(i) = J 7„(/-172), 1110≤ ≤ 2047。 Z n (i) = J 7„(/-172), 1110≤ ≤ 2047.
0, = 0或 939≤ ≤1109  0, = 0 or 939 ≤ ≤1109
经过 IFFT变换的 OFDM符号按照图 7所述， 加入循环前缀（ CP ) , 组成时域 OFDM符号。  The IFFT-transformed OFDM symbol is added to the cyclic prefix (CP) as shown in Fig. 7 to form a time domain OFDM symbol.
调制后的 OFDM符号， 按照图 4所述的帧结构， 依次加入保护间隔、 同步信号、 发射机识别信号后组成时隙。 再将 40个时隙连接组成物理层信 号帧。  The modulated OFDM symbol, according to the frame structure described in FIG. 4, sequentially adds a guard interval, a synchronization signal, and a transmitter identification signal to form a time slot. Then, 40 time slots are connected to form a physical layer signal frame.
本系统的上层数据流可以釆用包括 H.264、 AVS、 MPEG-2、 MPEG-4 等视频流， AC- 3、 AAC等音频流， 和其它多种数据类型的数据格式。 对 数据编码可包括单一媒体 （例如视频源编码、 文本） 和多媒体 （音频、 视 频、 文本和数据的混合） 在内的各种类型的广播数据。 The upper layer data stream of the system can use video streams including H.264, AVS, MPEG-2, MPEG-4, audio streams such as AC-3, AAC, and other data types of various data types. Encoding data can include single media (eg video source encoding, text) and multimedia (audio, video) Various types of broadcast data within the mix of frequency, text and data).
本技术领域的普通技术人员可以理解实现上述实施例方法携带的全部 或部分步骤是可以通过程序来指令相关的硬件完成， 所述的程序可以存储 于一种计算机可读存储介质中， 该程序在执行时， 包括方法实施例的步骤 之一或其组合。  One of ordinary skill in the art can understand that all or part of the steps carried by the method of implementing the above embodiments can be completed by a program to instruct related hardware, and the program can be stored in a computer readable storage medium. When executed, one or a combination of the steps of the method embodiments is included.
此外， 在本发明各个实施例中的各功能单元可以集成在一个处理模块 中， 也可以是各个单元单独物理存在， 也可以两个或两个以上单元集成在 一个模块中。 上述集成的模块既可以釆用硬件的形式实现， 也可以釆用软 件功能模块的形式实现。 所述集成的模块如果以软件功能模块的形式实现 并作为独立的产品销售或使用时， 也可以存储在一个计算机可读取存储介 质中。  In addition, each functional unit in each embodiment of the present invention may be integrated into one processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. The integrated modules, if implemented in the form of software functional modules and sold or used as stand-alone products, may also be stored in a computer readable storage medium.
上述提到的存储介质可以是只读存储器， 磁盘或光盘等。  The above-mentioned storage medium may be a read only memory, a magnetic disk or an optical disk or the like.
以上所述仅是本发明的优选实施方式， 应当指出， 对于本技术领域的 普通技术人员来说， 在不脱离本发明原理的前提下， 还可以做出若干改进 和润饰， 这些改进和润饰也应视为本发明的保护范围。  The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. It should be considered as the scope of protection of the present invention.

Claims

权利要求书 Claim
1、 一种移动多媒体广播发送系统， 其特征在于， 包括： A mobile multimedia broadcast transmitting system, comprising:
RS编码与字节交织器， 用于通过物理逻辑信道对上层数据流进行 RS 编码和字节交织；  An RS coding and byte interleaver for performing RS coding and byte interleaving on the upper layer data stream through a physical logical channel;
LDPC 编码器， 用于对所述 RS 编码与字节交织器输出的数据进行 An LDPC encoder, configured to perform data output by the RS encoding and the byte interleaver
LDPC编码， 得到比特数据； LDPC encoding to obtain bit data;
比特交织器，用于对所述 LDPC编码器输出的比特数据进行比特交织； 星座映射器， 用于对所述比特交织器输出的数据进行星座映射； 频域符号生成器， 用于将离散导频、 包含有系统信息的连续导频和经 过星座映射的数据符号复接在一起组成 OFDM频域符号；  a bit interleaver for performing bit interleaving on the bit data output by the LDPC encoder; a constellation mapper for constelling the data output by the bit interleaver; and a frequency domain symbol generator for using the discrete guide Frequency, contiguous pilots containing system information and data symbols mapped by constellation are multiplexed together to form an OFDM frequency domain symbol;
IFFT变换器， 用于将所述扰码器输出的频域符号经过 IFFT变换后产 生 OFDM时域符号； An IFFT converter, configured to generate an OFDM time domain symbol by performing IFFT transform on a frequency domain symbol output by the scrambler;
时域组帧器， 用于将所述 OFDM时域符号组成时隙后， 连接组成物理 层信号帧；  a time domain framer, configured to form the physical layer signal frame after the OFDM time domain symbols are formed into time slots;
发射器， 用于将所述物理层信号帧从基带信号变换至射频后发射， 其 中所述发射器使用无线信道内任意 5MHz带宽发射信号。  And a transmitter, configured to convert the physical layer signal frame from a baseband signal to a radio frequency, wherein the transmitter transmits the signal using any 5 MHz bandwidth in the wireless channel.
2、 如权利要求 1所述的移动多媒体广播发送系统， 其特征在于， 所述 物理层信号帧长度为 1秒， 包括 40个长度为 25毫秒的时隙， 所述时隙包 括 1个信标和 53个 OFDM符号， 所述信标包括 1个发射机标识信号和 2 个相同的同步信号， 所述发射机标识信号由频域随机序列依次进行 BPSK 映射和 IFFT变换后再经过周期延拓而得到，所述同步序列通过截取频域随 机序列后， 依次进行 BPSK和 IFFT变换而得到。  2. The mobile multimedia broadcast transmitting system according to claim 1, wherein the physical layer signal frame length is 1 second, and includes 40 time slots having a length of 25 milliseconds, wherein the time slot includes one beacon. And 53 OFDM symbols, the beacon includes 1 transmitter identification signal and 2 identical synchronization signals, and the transmitter identification signal is sequentially subjected to BPSK mapping and IFFT transformation by a frequency domain random sequence, and then cyclically extended. It is obtained that the synchronization sequence is obtained by performing BPSK and IFFT transformation after intercepting the frequency domain random sequence.
3、 如权利要求 2所述的移动多媒体广播发送系统， 其特征在于， 所述 发射机标识信号通过 117 比特信息标识， 承载所述发射机标识信号的子载 波数 ND = 128 , 通过 BPSK 调制， 所述发射机标识信号；r D(o由发射机标识 序列 TxID(Ii)映射产生， 映射方式为： 。3. The mobile multimedia broadcast transmitting system according to claim 2, wherein the transmitter identification signal is identified by 117-bit information, and the number of subcarriers carrying the transmitter identification signal is N D = 128, and is modulated by BPSK. The transmitter identification signal; r D (o is generated by mapping the transmitter identification sequence TxID(Ii), and the mapping manner is: .
Figure imgf000024_0001
Figure imgf000024_0001
4、 如权利要求 2所述的移动多媒体广播发送系统， 其特征在于， 所述 同步信号 (0为频带受限的伪随机信号， 长度 为 204. ,  The mobile multimedia broadcast transmitting system according to claim 2, wherein the synchronization signal (0 is a band-limited pseudo-random signal having a length of 204.
Sb(t) = Xb(i)e]'2m, ≤t≤Tb , 其中 N¾为承载所述同步信号的子载
Figure imgf000024_0002
 S b (t) = X b (i) e] '2m, ≤t≤T b, where N ¾ to carry the synchronization signal subcarriers
Figure imgf000024_0002
波数， 为承载二进制伪随机序列 ^^¾ )的 BPSK调制信号， （4\为同 步信号的子载波间隔， 子载波数^ =1024, 且 的 BPSK调制信号；^ () 由 映射产生， 映射方式为：
Figure imgf000024_0003
 Wavenumber , which is a BPSK modulated signal carrying a binary pseudo-random sequence ^^ 3⁄4 ), (4\ is the subcarrier spacing of the synchronization signal, the number of subcarriers is ^=1024, and the BPSK modulated signal; ^ () is generated by mapping, mapping mode for:
Figure imgf000024_0003
5、 如权利要求 4所述的移动多媒体广播发送系统， 其特征在于， 所述 二进制伪随机序列由线性反馈移位寄存器产生， 移位寄存器的初始值为 5. The mobile multimedia broadcast transmitting system according to claim 4, wherein the binary pseudo random sequence is generated by a linear feedback shift register, and an initial value of the shift register is
01110101101, 生成多项式为： x"+x9+l。 01110101101, the generator polynomial is: x"+x 9 +l.
6、 如权利要求 2所述的移动多媒体广播发送系统， 其特征在于， 所述 发射机标识、 同步序列和 OFDM符号间釆用带窗函数的保护间隔相交叠， 所述窗函数的表达式为： ，其中， t为时间变量,
Figure imgf000024_0004
The mobile multimedia broadcast transmitting system according to claim 2, wherein the guard identifier, the synchronization sequence, and the guard interval of the window function are overlapped between the OFDM symbols, and the expression of the window function is : , where t is a time variable,
Figure imgf000024_0004
T为常数， 为所述保护间隔的长度。  T is a constant and is the length of the guard interval.
7、 如权利要求 1所述的移动多媒体广播发送系统， 其特征在于， 所述 RS编码是由原始的 RS ( 255, M) 系统码通过截短后产生的 RS ( 192, K) 截短码，其中 M=K+63, K为一个码字中信息序列的字节数，所述 RS( 255, M ) 系统码的每个码元取自域 GF ( 256 ) , 该域的生成多项式为 p(x) = jc8 + jc4 + jc3 + jc2 + 1。 7. The mobile multimedia broadcast transmitting system according to claim 1, wherein the RS encoding is an RS (192, K) truncation code generated by truncating the original RS (255, M) system code. Where M = K + 63, K is the number of bytes of the information sequence in a codeword, each symbol of the RS (255, M) system code is taken from the domain GF (256), and the generator polynomial of the domain is p(x) = jc 8 + jc 4 + jc 3 + jc 2 + 1.
8、 如权利要求 7所述的移动多媒体广播发送系统， 其特征在于， 所述 RS ( 192, K)码包括 4种模式， 这 4种模式中 K的取值分别为 K=192、 Κ=168、 Κ=160和 Κ=144。  8. The mobile multimedia broadcast transmitting system according to claim 7, wherein the RS (192, K) code comprises four modes, wherein K values of the four modes are respectively K=192, Κ= 168, Κ = 160 and Κ = 144.
9、 如权利要求 8所述的移动多媒体广播发送系统， 其特征在于， 所述 192— 9. The mobile multimedia broadcast transmitting system according to claim 8, wherein: 192-
192, K)码的生成多项式的表达式为 g(x)= ;  The expression of the generator polynomial of 192, K) code is g(x)= ;
当 K=192时， RS ( 192, 192) 的生成多项式表达式的系数 &为：
Figure imgf000025_0001
When K=192, the coefficient & of the generator polynomial expression of RS (192, 192) is:
Figure imgf000025_0001
当 K=168时， RS192, 168 ) 的生成多项式表达式的系数 &为:  When K=168, the coefficient & of the generator polynomial expression of RS192, 168) is:
Figure imgf000025_0002
Figure imgf000025_0002
当 K=160时， RS U92, 160 ) 的生成多项式表达式的系数 &为：  When K=160, the coefficient & of the generator polynomial expression of RS U92, 160 ) is:
Figure imgf000025_0003
Figure imgf000025_0003
当 K=144时， RS ( 192, 144) 的生成多项式表达式的系数 &为：  When K=144, the coefficient & of the generator polynomial expression of RS (192, 144) is:
Figure imgf000025_0004
Figure imgf000025_0004
10、 如权利要求 9所述的移动多媒体广播发送系统， 其特征在于， 所 述上层数据流以字节为单位，从左至右逐列输入 RS编码和字节交织器，其 中， RS编码按行进行编码， 字节交织器的起始字节映射在某个时隙的起始 点发送。 O 10. The mobile multimedia broadcast transmitting system according to claim 9, wherein: The upper layer data stream is input into the RS code and the byte interleaver column by column from left to right, wherein the RS code is encoded in rows, and the start byte of the byte interleaver is mapped in a certain time slot. The starting point is sent. O
11、 权利要求 10 述的移动多媒体广播发送系统， 其特征在于， 所述 卜  11. The mobile multimedia broadcast transmitting system of claim 10, wherein:
LDPC编码后的输出块长为 9216比特， 码率分别为 1/2和 3/4, 对应不同的 码率， 所述字节交织器 o相应的交织模式分别为：
Figure imgf000026_0002
The output block length of the LDPC encoding is 9216 bits, and the code rates are 1/2 and 3/4, respectively, corresponding to different code rates. The corresponding interleaving modes of the byte interleaver o are:
Figure imgf000026_0002
其中， MI为字节交织器的行数， 字节交织器中的全部字节为 Mix 192 字节。  Where MI is the number of lines of the byte interleaver, and all bytes in the byte interleaver are Mix 192 bytes.
12、 如权利要求 1 所述的移动多媒体广播 Ο发送系统， 其特征在于， 所 述比特交织器釆用 384 x 216的块交织器；从 LDPC编码器输出的比特数据 按照从上到下的顺序依次写入所述块交织器的每一寸行， 直至填满整个块交 织器， 再从左到右的按列依次读出， 其中比特交织器的输出与时隙对齐。  12. The mobile multimedia broadcast port transmission system according to claim 1, wherein said bit interleaver uses a block interleaver of 384 x 216; and bit data output from the LDPC encoder is in order from top to bottom. Each inch of the block interleaver is sequentially written until the entire block interleaver is filled, and then read from left to right in columns, wherein the output of the bit interleaver is aligned with the time slot.
卜  Bu
13、 如权利要求 1 所述的移动多媒体广播发送系统， 其00 特征在于， 所 述频域符号生成器在每个 OFDM符号中将 234个离散导频、 76个连续导频、 1566个数据子载波复接在一起， 成为 1876个有效子载波。  13. The mobile multimedia broadcast transmitting system according to claim 1, wherein the frequency domain symbol generator has 234 discrete pilots, 76 consecutive pilots, and 1566 data sub-samples in each OFDM symbol. The carriers are multiplexed together to become 1876 active subcarriers.
14、 如权利要求 13所述的移动多媒体广播发送系统， 其特征在于，0 0所 o 述 76个连续导频使用所述 1876个有效子载波中第 0, 6, 66, 76, 92, 132, 14. The mobile multimedia broadcast transmitting system according to claim 13, wherein said 76 consecutive pilots use 0, 6, 66, 76, 92, 132 of said 1876 valid subcarriers. ,
150, 170, 206, 228, 260, 294, 296, 328, 338, 382, 392, 406, 462,150, 170, 206, 228, 260, 294, 296, 328, 338, 382, 392, 406, 462,
474, 480, 494, 552, 562, 582, 624, 630, 664, 668, 738, 744, 760, 790, 806, 834, 850, 922, 937, 938, 952, 1024, 1040, 1068, 1084,474, 480, 494, 552, 562, 582, 624, 630, 664, 738, 738, 744, 760, 790, 806, 834, 850, 922, 937, 938, 952, 1024, 1040, 1068, 1084,
1114, 1210, 1244, 1114, 1210, 1244,
1394, 1400, 1412, 1468, 1482, 1492,
Figure imgf000026_0001
1394, 1400, 1412, 1468, 1482, 1492,
Figure imgf000026_0001
1646, 1668, 1704, 1724, 1742, 1782, 1798, 1808, 1868, 1875个子载 波， 并在其中第 6, 406, 1084, 1482, 66, 462, 1114, 1492, 76, 474, 1130, 1536, 92, 480, 1172, 1546, 132, 494, 1206, 1578, 150, 552, 1210, 1580, 170, 562, 1244, 1614, 206, 582, 1250, 1646, 228, 624, 1292, 1668, 260, 630, 1312, 1704, 294, 664, 1322, 1724, 296, 668, 1380, 1742, 328, 738, 1394, 1782, 338, 744, 1400, 1798, 382, 760, 1412, 1808, 392, 790, 1468, 1868共 64个子载波中承载 16比特系统信 息， 所述系统信息包括长度为 6比特的时隙号、 长度为 1 比特的字节交织 器同步标识、 长度为 1 比特的控制逻辑信道变更指示和长度为 8比特的保 留字； 所述连续导频以
Figure imgf000027_0001
的方式映射到子 载波上， 其中， 同一时隙内不同 OFDM符号的相同连续子载波点上传输的 符号相同。 1646, 1668, 1704, 1724, 1742, 1782, 1798, 1808, 1868, 1875 subcarriers, and in them 6, 406, 1084, 1482, 66, 462, 1114, 1492, 76, 474, 1130, 1536, 92, 480, 1172, 1546, 132, 494, 1206, 1578, 150, 552, 1210, 1580, 170, 562, 1244, 1614, 206, 582, 1250, 1646, 228, 624, 1292, 1668, 260, 630, 1312, 1704, 294, 664, 1322, 1724, 296, 668, 1380, 1742, 328, 738, 1394, 1782, 338, 744, 1400, 1798, 382, 760, 1412, 1808, 392, 790, 1468, 1868 A total of 64 subcarriers carrying 16-bit system information, the system information includes a slot number of 6 bits in length, a byte interleaver synchronization identifier of 1 bit length, and a length of 1 bit. Control logical channel change indication and a reserved word of length 8 bits; the continuous pilot is
Figure imgf000027_0001
The manner is mapped to the subcarriers, wherein the symbols transmitted on the same consecutive subcarrier points of different OFDM symbols in the same slot are the same.
15、 如权利要求 14所述的移动多媒体广播发送系统， 其特征在于， 当 每个时隙中 OFDM符号的编号为 n时， OFDM符号中离散导频对应的子载 波编号 m取值为：  The mobile multimedia broadcast transmitting system according to claim 14, wherein when the number of the OFDM symbol in each slot is n, the subcarrier number m corresponding to the discrete pilot in the OFDM symbol is:
当 mod(w,2) = 0  When mod(w,2) = 0
Figure imgf000027_0002
Figure imgf000027_0002
16、 如权利要求 1 所述的移动多媒体广播发送系统， 其特征在于， 所 述扰码器使用的伪随机序列的生成多项式为： x12+x"+x8+x6+l; 所述扰码 分为 8种模式， 对应的寄存器初始值分别为： The mobile multimedia broadcast transmitting system according to claim 1, wherein a generator polynomial of the pseudo random sequence used by the scrambler is: x 12 + x" + x 8 + x 6 + l; The scrambling code is divided into 8 modes, and the corresponding initial values of the registers are:
1 )扰码模式 0: 初始值 000000000001 ,  1) Scrambling mode 0: initial value 000000000001,
2 )扰码模式 1: 初始值 000010010011,  2) Scrambling mode 1: initial value 000010010011,
3 )扰码模式 2: 初始值 000001001100,  3) Scrambling mode 2: initial value 000001001100,
4)扰码模式 3: 初始值 001010110011,  4) Scrambling mode 3: Initial value 001010110011,
5 )扰码模式 4: 初始值 011101000100,  5) Scrambling mode 4: Initial value 011101000100,
6 )扰码模式 5: 初始值 010001001100,  6) Scrambling mode 5: initial value 010001001100,
7 )扰码模式 6: 初始值 000101101101,  7) Scrambling mode 6: Initial value 000101101101,
8)扰码模式 7: 初始值 101010110011;  8) Scrambling mode 7: Initial value 101010110011;
所述伪随机序列在每个时隙的开头重置，所有时隙都被相同图样扰码。  The pseudo-random sequence is reset at the beginning of each time slot, and all time slots are scrambled by the same pattern.
17、 如权利要求 1 所述的移动多媒体广播发送系统， 其特征在于， 所 述 IFFT变换器将 1876个有效子载波放在 2048个子载波的第 1 ~ 938和第 1110 ~ 2047子载波上后进行 2048点 IFFT变换。 17. The mobile multimedia broadcast transmitting system according to claim 1, wherein said IFFT converter places 1876 effective subcarriers on 1st to 938th and 20th of 2048 subcarriers. The 2048-point IFFT conversion is performed on the 1110 ~ 2047 subcarriers.
18、 如权利要求 1至 17之一所述的移动多媒体广播发送系统， 其特征 在于， 所述时域组帧器将调制后的 OFDM符号依次加入保护间隔、 同步信 号、 发射机识别信号后组成时隙， 再将 40个时隙连接组成物理层信号帧。  The mobile multimedia broadcast transmitting system according to any one of claims 1 to 17, wherein the time domain framer sequentially adds the modulated OFDM symbols to the guard interval, the synchronization signal, and the transmitter identification signal. The time slot, then 40 time slots are connected to form a physical layer signal frame.
PCT/CN2010/070476 2009-02-11 2010-02-02 Mobile multimedia broadcast transmission system WO2010091622A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN200910078052.X 2009-02-11
CN200910078052A CN101800725B (en) 2009-02-11 2009-02-11 Mobile multimedia broadcast transmission system

Publications (1)

Publication Number Publication Date
WO2010091622A1 true WO2010091622A1 (en) 2010-08-19

Family

ID=42561408

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2010/070476 WO2010091622A1 (en) 2009-02-11 2010-02-02 Mobile multimedia broadcast transmission system

Country Status (3)

Country Link
CN (1) CN101800725B (en)
HK (1) HK1147149A1 (en)
WO (1) WO2010091622A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102611463A (en) * 2012-04-09 2012-07-25 上海交通大学 Cascade coding and decoding system and method of multi-system low-density parity check code
CN113783597A (en) * 2021-08-10 2021-12-10 中国科学院国家空间科学中心 Variable coding modulation data transmission framing system and framing method for near-earth remote sensing satellite

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016049909A1 (en) * 2014-09-30 2016-04-07 华为技术有限公司 Data transmission method and related device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1909546A (en) * 2006-08-18 2007-02-07 清华大学 Transmitting method for physical layer descending chain circuit frame of broad band wireless multimedia system
CN1960358A (en) * 2006-10-20 2007-05-09 北京泰美世纪科技有限公司 Digital information transmission method of a kind of multicarrier digital mobile multimedia broadcast system
CN1960357A (en) * 2006-10-20 2007-05-09 北京泰美世纪科技有限公司 Multicarrier digital mobile multimedia broadcast system, and digital information transmission method
CN101018223A (en) * 2006-10-22 2007-08-15 北京创毅视讯科技有限公司 A transmission system and method of the mobile digital multimedia broadcast signals
CN101018104A (en) * 2006-11-01 2007-08-15 北京创毅视讯科技有限公司 Mobile digital multimedia broadcast signal transmission system and channel bandwidth change method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1909546A (en) * 2006-08-18 2007-02-07 清华大学 Transmitting method for physical layer descending chain circuit frame of broad band wireless multimedia system
CN1960358A (en) * 2006-10-20 2007-05-09 北京泰美世纪科技有限公司 Digital information transmission method of a kind of multicarrier digital mobile multimedia broadcast system
CN1960357A (en) * 2006-10-20 2007-05-09 北京泰美世纪科技有限公司 Multicarrier digital mobile multimedia broadcast system, and digital information transmission method
CN101018223A (en) * 2006-10-22 2007-08-15 北京创毅视讯科技有限公司 A transmission system and method of the mobile digital multimedia broadcast signals
CN101018104A (en) * 2006-11-01 2007-08-15 北京创毅视讯科技有限公司 Mobile digital multimedia broadcast signal transmission system and channel bandwidth change method

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102611463A (en) * 2012-04-09 2012-07-25 上海交通大学 Cascade coding and decoding system and method of multi-system low-density parity check code
CN102611463B (en) * 2012-04-09 2014-08-06 上海交通大学 Cascade coding and decoding system and method of multi-system low-density parity check code
CN113783597A (en) * 2021-08-10 2021-12-10 中国科学院国家空间科学中心 Variable coding modulation data transmission framing system and framing method for near-earth remote sensing satellite
CN113783597B (en) * 2021-08-10 2022-11-01 中国科学院国家空间科学中心 Variable coding modulation data transmission framing system and framing method for near-earth remote sensing satellite

Also Published As

Publication number Publication date
CN101800725A (en) 2010-08-11
HK1147149A1 (en) 2011-07-29
CN101800725B (en) 2012-10-24

Similar Documents

Publication Publication Date Title
WO2010091617A1 (en) Mobile multimedia broadcast transmission system
US11190834B2 (en) Apparatus for transmitting broadcast signals, apparatus for receiving broadcast signals, method for transmitting broadcast signals and method for receiving broadcast signals
WO2010091618A1 (en) Mobile multimedia broadcast transmission system
US10623534B2 (en) Apparatus for transmitting signaling information, apparatus for receiving signaling information, method for transmitting signaling information and method for receiving signaling information
CN107078847B (en) Apparatus and method for transceiving broadcast signals
US9756363B2 (en) Apparatus for transmitting media data via streaming service, apparatus for receiving media data via streaming service, method for transmitting media data via streaming service and method for receiving media data via streaming service
KR101830744B1 (en) Apparatus for transmitting broadcast signals, apparatus for receiving broadcast signals, method for transmitting broadcast signals and method for receiving broadcast signals
CN105794166B (en) Method and apparatus for transmitting and receiving broadcast signal
CN111510250B (en) Apparatus and method for transmitting and receiving broadcast signal
WO2008049282A1 (en) A multi-carrier digital mobile multimedia broadcast system and the digital information transmission method thereof
KR101911274B1 (en) Broadcast signal transmission apparatus, broadcast signal reception apparatus, broadcast signal transmission method, and broadcast signal reception method
KR102004274B1 (en) Broadcast signal transmitting apparatus, broadcast signal receiving apparatus, broadcast signal transmitting method, and broadcast signal receiving method
CN107005522B (en) Broadcast signal transmitting and receiving apparatus and method
WO2010091620A1 (en) Mobile multimedia broadcast transmission system
CN100493179C (en) Transmission method for raio multimedic broadcast system and its system
WO2010091622A1 (en) Mobile multimedia broadcast transmission system
CN111277531B (en) Apparatus and method for transmitting and receiving broadcast signal

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10740911

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10740911

Country of ref document: EP

Kind code of ref document: A1