CN102957942A - Method, device and system for data transmission in digital multimedia broadcasting - Google Patents

Abstract

The embodiment of the present invention proposes a method for transmitting data in digital multimedia broadcasting, including the following steps: the digital multimedia broadcasting sending end generates transmission data frame allocation information, and sends the transmission data frame allocation information to the digital multimedia broadcasting receiving end, and the digital multimedia broadcasting The multimedia broadcasting receiving end selectively receives service data from the digital multimedia broadcasting sending end according to the transmission data frame allocation information. The embodiment of the present invention also proposes a system for transmitting data in digital multimedia broadcasting, a digital multimedia broadcasting sending end and a digital multimedia broadcasting receiving end. By applying the embodiment of the present invention, the purpose of reducing the working energy consumption of the receiver can be achieved.

Description

Method, device and system for transmitting data in digital multimedia broadcasting

technical field

The present invention relates to the technical field of digital multimedia broadcasting, in particular, the present invention relates to a method, device and system for transmitting data in digital multimedia broadcasting.

Background technique

Digital Multimedia Broadcasting (Digital Multimedia Broadcasting, DMB) is a new concept multimedia mobile broadcasting service that integrates communication and broadcasting. In addition to supporting traditional audio broadcasting, this technology will also be able to transmit various multimedia information such as traffic information and news to mobile terminals through MPEG-4H.264, MPEG-2, AAC+, etc., providing high-quality Quality sound quality and diverse data services.

The biggest feature of digital multimedia broadcasting is that it is broadcast, point-to-multipoint, point-to-face, and the cost of broadcasting information has nothing to do with the number of users. Therefore, digital multimedia broadcasting, as an important part of the information communication industry, plays an important role in the construction of national information infrastructure, the realization of universal service and the national information security strategy.

In the digital multimedia broadcasting system, due to the point-to-multipoint characteristics of information transmission, the data transmitted in the broadcast downlink includes all user data information, and the receiver must receive the downlink data regardless of whether it is needed , after receiving, the expected data is retained, and the undesired data is discarded. This requires that the receiver must always be in the working state, that is, no matter whether the currently transmitted service data is the service data expected by the receiver, the receiver must receive it. Therefore, in this case, the receiver needs relatively large energy consumption. In the case that the receiver is a mobile terminal, this continuous working condition will inevitably lead to an increase in the power consumption of the mobile terminal, and since its working time is limited by the battery capacity, the energy consumption directly affects the performance of the terminal.

Contents of the invention

The present invention aims at at least solving or alleviating one of the above-mentioned technical defects, especially through the method, device and system for transmitting data in digital multimedia broadcasting proposed by the present invention, so as to reduce power consumption.

In order to achieve the above object, one aspect of the present invention proposes a method for transmitting data in digital multimedia broadcasting, comprising the following steps:

The digital multimedia broadcasting sending end generates transmission data frame allocation information, and sends the transmission data frame allocation information to the digital multimedia broadcasting receiving end, and the digital multimedia broadcasting receiving end selectively selects from the transmission data frame allocation information according to the transmission data frame allocation information The digital multimedia broadcasting sender receives service data.

Another aspect of the present invention proposes a system for transmitting data in digital multimedia broadcasting, the system includes a digital multimedia broadcasting sending end and a digital multimedia broadcasting receiving end, wherein:

The digital multimedia broadcasting sending end is used to generate transmission data frame allocation information, and send the transmission data frame allocation information to the digital multimedia broadcasting receiving end;

The DMB receiver is configured to selectively receive service data from the DMB sender according to the transmission data frame allocation information.

Another aspect of the present invention also proposes a digital multimedia broadcasting sending end, including: a data frame distribution information processing unit, a physical signal frame multiplexing unit and a radio frequency transmitting unit, wherein:

A data frame allocation information processing unit, configured to generate transmission data frame allocation information, and sequentially perform channel coding, bit interleaving, and symbol mapping processing on the transmission data frame allocation information;

A physical signal frame multiplexing unit, configured to multiplex the transmission data frame allocation information and service data after the above-mentioned channel coding, bit interleaving and symbol mapping processing into a physical signal frame, and send the physical signal frame to the radio frequency transmitting unit ;

The radio frequency transmitting unit is configured to transmit the physical signal frame.

Another aspect of the present invention also proposes a digital multimedia broadcast receiving end, including a transmission data frame distribution information analyzing unit and a service data receiving unit, wherein:

The transmission data frame allocation information analysis unit is used to receive the transmission data frame allocation information generated by the digital multimedia broadcasting sending end, and analyze the transmission data frame allocation information to determine the working period of receiving service data and the period of not receiving service data non-working period;

The service data receiving unit is used for the digital multimedia broadcasting to receive service data corresponding to the transmission data frame allocation information during the working period, and not to receive the service data when not in the working period.

In the technical solution proposed by the present invention, the digital multimedia broadcasting sending end generates transmission data frame allocation information, and this information can instruct the digital multimedia broadcasting receiving end to perform corresponding receiving processing on the target logical frame data, so the digital multimedia broadcasting receiving end does not receive blindly Instead, it can selectively receive service data from the digital multimedia broadcasting sending end, for example, shutting down its working module during non-target logical frames, so that the purpose of reducing the working energy consumption of the receiver can be achieved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, wherein:

FIG. 1 is a flowchart of a method for transmitting data in digital multimedia broadcasting according to an embodiment of the present invention;

2 is a schematic diagram of a logical frame and a physical layer frame structure according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an example frame structure of an embodiment of the present invention;

FIG. 4 is a schematic diagram of subframe allocation mode 1 in Embodiment 1 of the present invention;

FIG. 5 is a schematic diagram of subframe allocation mode 2 in Embodiment 2 of the present invention;

FIG. 6 is a schematic diagram of subframe allocation mode 3 in Embodiment 3 of the present invention;

FIG. 7 is a schematic diagram of reducing power consumption of a receiver according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a system for transmitting data in digital multimedia broadcasting according to an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a digital multimedia broadcasting sending end according to an embodiment of the present invention;

FIG. 10 is a detailed schematic diagram of the structure of a digital multimedia broadcasting sending end according to an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of a digital multimedia broadcast receiving end according to an embodiment of the present invention;

FIG. 12 is a detailed schematic diagram of the structure of a digital multimedia broadcast receiving end according to an embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

In order to achieve the object of the present invention, the embodiment of the present invention proposes a method for transmitting data in digital multimedia broadcasting.

As shown in Figure 1, the following steps are included:

S101: The digital multimedia broadcasting sending end generates transmission data frame allocation information, and sends the transmission data frame allocation information to the digital multimedia broadcasting receiving end.

Here, preferably, the digital multimedia broadcasting is digital audio broadcasting or digital video broadcasting. However, the present invention is not limited to digital audio broadcasting or digital video broadcasting, but can also be embodied in some still media (Still media) broadcasting. Static media refers to digital multimedia whose content does not change over time, such as text and images.

In one embodiment, when the digital multimedia broadcasting is digital audio broadcasting, sending the transmission data frame allocation information to the digital multimedia broadcasting receiving end may specifically include the following steps:

The digital multimedia broadcasting sending end sequentially performs channel coding, bit interleaving and symbol mapping processing on the transmission data frame allocation information; the digital multimedia broadcasting sending end combines the transmission data frame allocation information after the above channel coding, bit interleaving and symbol mapping processing with The service data is multiplexed into physical signal frames, and the physical signal frames are sent to the digital multimedia broadcasting receiving end.

Preferably, multiplexing the transmission data frame allocation information processed by the above-mentioned channel coding, bit interleaving and symbol mapping with the service data into a physical signal frame may specifically include the following steps: combining the above-mentioned channel coding, bit interleaving and symbol mapping The transmission data frame allocation information processed by symbol mapping and the service data form a logical frame; the logical frame is mapped into a physical signal frame and sent.

Preferably, the four physical signal frames may form a physical superframe, and each physical signal frame may include four physical subframes. Each physical subframe can contain 1 beacon symbol and Sn OFDM symbols; 4 described continuous logical frames form a logical superframe, and each logical frame includes 4 continuous logical subframes, and each physical subframe contains 1 Beacon symbols and Sn OFDM symbols.

More specifically, each OFDM symbol preferably includes 36 bits, and the bits c0-c35 included in each OFDM symbol are explained in detail as follows:

in:

c ₀ ~ c ₁ represent the position of the current physical layer signal frame;

c ₂ ~ c ₃ represent the current subframe position;

c ₄ ~ c ₅ represent the subframe allocation method;

c ₆ ~ c ₇ represent the modulation mode of the transmission data frame allocation information;

c ₈ ~ c ₉ represent the modulation mode of service data;

c ₁₀ ~ c ₁₁ represent the layered modulation indication of service data;

c ₁₂ indicates that the coding of business data adopts the indication of uniform protection;

c ₁₃ ~ c ₁₄ represent the LDPC code rate of business data;

c ₁₅ ~ c ₁₆ represent the LDPC code rate of business data;

c ₁₇ ~ c ₂₆ means to keep Rfa;

c ₂₇ ~c ₂₉ represent the CRC check digit;

c ₃₀ to c ₃₅ represent reserved Rfu.

In a preferred embodiment, according to the arrangement order of 4 consecutive logical subframes in the logical frame, the 4 logical subframes in the logical frame are mapped to 4 physical subframes in the physical signal frame, wherein Sn is 56.

In another preferred embodiment, 8 consecutive logical subframes in every 2 logical frames in 4 consecutive logical frames are used as a group, the logical subframes in the group are interleaved with each other, and the logical subframes in the group are interleaved with each other A subframe is mapped to two consecutive physical signal frames, where Sn is 111.

In another preferred embodiment, 4 consecutive logical frames are used as a group, and the i-th logical subframe in each logical frame in the group is sequentially mapped to the i-th physical signal frame, where i is 1, 2, 3 or 4.

In the above steps, although four physical signal frames form a physical superframe, and each physical signal frame includes four physical subframes as an example, the present invention is described in detail, those skilled in the art can realize that the present invention does not It is limited to four physical signal frames forming a physical superframe, and it is not limited to each physical signal frame including four physical subframes. In essence, the number of physical signal frames that make up a physical superframe and the number of physical subframes included in each physical signal frame can be changed, and the bits of OFDM symbols and the meaning of each bit can be changed to a certain extent . When the number of subframes is not four, the logical subframes in each logical frame are allocated to the physical layer frame while keeping the sequence unchanged.

S102: The digital multimedia broadcasting receiving end selectively receives service data from the digital multimedia broadcasting sending end according to the transmission data frame allocation information.

Here, specific steps can be taken: the digital multimedia broadcasting receiving end determines the working period for receiving service data and the non-working period for not receiving service data according to the transmission data frame allocation information; when in the working period, the digital multimedia broadcasting receiving corresponding For the service data of the transmission data frame allocation information, when not in the working period, the digital multimedia broadcasting does not receive the service data.

A preferred embodiment of the present invention applied to a digital audio broadcasting system will be further described below with reference to the accompanying drawings.

FIG. 2 is a schematic diagram of a logical frame and a physical layer frame structure of an embodiment of the present invention; FIG. 3 is a schematic diagram of an example frame structure of an embodiment of the present invention.

As shown in Figure 2 and Figure 3, the OFDM-based digital audio broadcasting system transmission structure includes four layers, which are superframe, frame, subframe and OFDM symbol. Each superframe consists of 4 frames, and each frame consists of 4 subframes. The superframe length is 2560ms, each superframe consists of 4 physical layer signal frames with a length of 640ms, each physical layer signal frame includes 4 subframes with a length of 160ms, and each subframe includes 1 beacon and _SN OFDM symbols. Each physical layer signal frame carries data of one logical frame. Among them, the logical frame structure and the physical layer signal frame structure are shown in FIG. 2 , and the structure diagram of the subframe is shown in FIG. 3 . The values of _SN in these figures are shown in Table 1.

Table 1

bit Information description c ₀ ~c ₁ The position of the current physical layer signal frame c ₂ ~c ₃ Current subframe position c ₄ ~ c ₅ Subframe allocation method c ₆ ~c ₇ Modulation method of business description information c ₈ ~ c ₉ Modulation method of business data c ₁₀ ~c ₁₁ Hierarchical modulation indication of business data c ₁₂ The coding of business data adopts the indication of uniform protection _c13 ～ _c14 LDPC code rate of business data c ₁₅ ~c ₁₆ LDPC code rate of business data _c17 ～ _c26 Keep Rfa c ₂₇ ~ c ₂₉ CRC check digit

c ₃₀ ~c ₃₅ Keep Rfu

A logical frame is a data frame before subframe allocation, including synchronization information, system information, service description information, and service data. Each logical frame includes 4 logical subframes, and each logical subframe includes 1 beacon symbol and S _N OFDM symbols. performing subframe allocation on logical subframes SF _{p, q} (p= _{1, 2, 3} , 4, q=1, 2, 3, 4) in four consecutive logical frames F 1 F 2 F 3 F ₄ , SF _{p, q} represents the qth logical subframe in the pth logical frame.

Among them, c ₀ ~ c ₅ bits are defined as follows:

c ₀ ~c ₁ : the position of the current physical layer signal frame in a superframe, 00 indicates the first frame; 01 indicates the second frame; 10 indicates the third frame; 11 indicates the fourth frame. c ₂ ˜c ₃ : the position of the current subframe in a physical layer signal frame, 00 indicates the first subframe; 01 indicates the second subframe; 10 indicates the third subframe; 11 indicates the fourth subframe. c ₄ ˜c ₅ : subframe allocation mode, 00 is reserved; 01 indicates subframe allocation mode 1; 10 indicates subframe allocation mode 2; 11 indicates subframe allocation mode 3.

Preferably, the present invention can adopt three different subframe allocation modes, each allocation mode is shown in FIG. 4 , FIG. 5 and FIG. 6 . FIG. 4 is a schematic diagram of subframe allocation mode 1 in Embodiment 1 of the present invention. In FIG. 4 , the subframe allocation mode 1 does not change the original order of the four logical subframes in each logical frame. Specifically, according to the arrangement sequence of 4 consecutive logical subframes in the logical frame, the 4 logical subframes in the logical frame are mapped to 4 physical subframes in the physical signal frame, where Sn is 56.

FIG. 5 is a schematic diagram of subframe allocation mode 2 in Embodiment 2 of the present invention. In FIG. 5 , in the subframe allocation mode 2, each logical subframe in every 2 consecutive logical frames in 4 consecutive logical frames forms a physical layer signal frame in the manner shown in FIG. 5 . Specifically, 8 consecutive logical subframes in every 2 logical frames in 4 consecutive logical frames are used as a group, the logical subframes in the group are interleaved with each other, and the group of interleaved logical subframes are mapped to 2 consecutive physical signal frames, where Sn is 111.

FIG. 6 is a schematic diagram of subframe allocation mode 3 in Embodiment 3 of the present invention. In subframe allocation mode 3, each logical subframe of 4 consecutive logical frames is composed into a physical layer signal frame in the manner shown in FIG. 6 . Specifically, taking 4 consecutive logical frames as a group, the i-th logical subframe in each logical frame in the group is sequentially mapped to the i-th physical signal frame, where i is 1, 2, 3 or 4.

Table 2 shows the preferred values of the number of OFDM symbols in each subframe in the three subframe allocation modes.

Table 2

parameters symbol Transmission mode 1 Transmission Mode 2 Transmission Mode 3 Number of OFDM symbols per subframe S _N 56 111 61

It can be seen that when the present invention is applied to the field of digital audio broadcasting, in the method of the embodiment of the present invention, firstly, according to the distribution state of the digital audio broadcasting sending end to the sending time of multiple logical frame data, the digital audio broadcasting at the sending end forms a The transmission data frame allocation information used to control the logical frame allocation control, and channel coding, bit interleaving and symbol mapping are performed on it; then it is multiplexed with other pilot information and business information to form a transmission signal frame and allocated according to the transmission data frame The information transmits the corresponding frame of the broadcast signal; then, after time and frequency synchronization, channel estimation and equalization at the receiving end of the system, the demodulated data symbols carrying the transmission data frame allocation information are extracted; and then the symbols are deinterleaved and decoded operation; and extract the control information related to logical frame allocation from the decoded transmission data frame allocation information, and adjust the working switch status of the receiver and the target logical frame to perform corresponding receiving processing. Through the method of the embodiment of the present invention, the receiver can be instructed to process the received information effectively, so it can be widely used in the digital multimedia broadcasting system and reduce the energy consumption of the receiver.

Based on the above detailed description, FIG. 7 is a schematic diagram of reducing power consumption of a receiver according to an embodiment of the present invention.

As shown in Figure 7, if the current target service data is logical frame 1 and is sent according to subframe allocation method 2, the receiver only needs to use subframes 1 and 3 of the first two physical signal frames of each superframe It is only necessary to perform signal reception, and the rest of the time may not receive signals, so as to achieve the purpose of receiving the target service and reducing the working energy consumption of the receiver.

The invention also proposes a system for transmitting data in digital multimedia broadcasting. FIG. 8 is a schematic structural diagram of a system for transmitting data in digital multimedia broadcasting according to an embodiment of the present invention.

As shown in FIG. 8 , the system includes a DMB sending end 810 and a DMB receiving end 820 .

The digital multimedia broadcasting sending end 810 is configured to generate transmission data frame allocation information, and send the transmission data frame allocation information to the digital multimedia broadcasting receiving end;

The DMB receiving end 820 is configured to selectively receive service data from the DMB sending end according to the transmission data frame allocation information.

In the above system, the digital multimedia broadcasting is preferably digital audio broadcasting. When it is digital audio broadcasting, the digital multimedia broadcasting sending end 810 can be used to sequentially perform channel coding, bit interleaving and symbol mapping processing on the transmission data frame allocation information, and will undergo the above channel coding, bit interleaving and symbol mapping processing The subsequent transmission data frame allocation information and the service data are multiplexed into a physical signal frame, and the physical signal frame is sent to the digital multimedia broadcasting receiving end 820 .

In one embodiment, the digital multimedia broadcasting sending end 810 is configured to form a logical frame with the transmission data frame allocation information processed by the above-mentioned channel coding, bit interleaving and symbol mapping and the service data, and combine the logical The frame is mapped to a physical signal frame and sent; wherein 4 physical signal frames form a physical superframe, and each physical signal frame includes 4 physical subframes, and each physical subframe includes 1 beacon symbol and Sn OFDM symbols; 4 consecutive logical frames form a logical superframe, each logical frame includes 4 consecutive logical subframes, and each physical subframe includes 1 beacon symbol and Sn OFDM symbols.

Wherein, each OFDM symbol includes bits c0-c35;

in:

c ₀ ~ c ₁ represent the position of the current physical layer signal frame;

c ₂ ~ c ₃ represent the current subframe position;

c ₄ ~ c ₅ represent the subframe allocation method;

c ₆ ~ c ₇ represent the modulation mode of the transmission data frame allocation information;

c ₈ ~ c ₉ represent the modulation mode of service data;

c ₁₀ ~ c ₁₁ represent the layered modulation indication of service data;

c ₁₂ indicates that the coding of business data adopts the indication of uniform protection;

c ₁₃ ~ c ₁₄ represent the LDPC code rate of business data;

c ₁₅ ~ c ₁₆ represent the LDPC code rate of business data;

c ₁₇ ~ c ₂₆ means to keep Rfa;

c ₂₇ ~c ₂₉ represent the CRC check digit;

c ₃₀ to c ₃₅ represent reserved Rfu.

In one embodiment, the digital multimedia broadcasting sending end 810 is configured to map the 4 logical subframes in the logical frame into the physical signal frame according to the sequence of the 4 consecutive logical subframes in the logical frame. 4 physical subframes, where Sn is 56.

In another embodiment, the digital multimedia broadcasting sending end 810 is configured to use 8 consecutive logical subframes in every 2 logical frames in 4 consecutive logical frames as a group, and interleave the logical subframes in the group, And map the group of mutually interleaved logical subframes into two consecutive physical signal frames, where Sn is 111.

In another embodiment, the digital multimedia broadcasting sending end 810 is configured to take 4 consecutive logical frames as a group, and sequentially map the i-th logical subframe in each logical frame in the group to the i-th physical signal frame, where i is 1, 2, 3 or 4.

Preferably, when the digital multimedia broadcasting is digital audio broadcasting, the digital multimedia broadcasting receiving end 820 is used to determine the working period for receiving service data and the non-working period for not receiving service data according to the transmission data frame allocation information; During the working period, the digital multimedia broadcasting receives service data corresponding to the transmission data frame allocation information, and when not in the working period, the digital multimedia broadcasting does not receive the service data.

It can be seen that, in the embodiment of the present invention, the transmission data frame allocation information can be used to instruct the receiver to selectively receive the data of the target logical frame, and to shut down its working module during the period of the non-target logical frame, thereby reducing the energy consumption of the receiver. Specifically, the system according to the present invention can define a transmission data frame allocation signal for indicating logical frame allocation at the sending end, and perform encoding, interleaving and symbol mapping on it, and combine the transmission data frame allocation information with other service data Sending; the receiver at the receiving end receives the transmission data frame allocation information to obtain the working status information about the allocation of multiple logical frames at the transmitting end, and performs corresponding receiving processing on the receiver's destination logical frame data according to this information, during the non-destination logical frame period Turn off its working module, so as to achieve the purpose of reducing the energy consumption of the receiver.

The invention also proposes a digital multimedia broadcasting sending end.

FIG. 9 is a schematic structural diagram of a digital multimedia broadcasting sending end according to an embodiment of the present invention. As shown in Figure 9, it includes: a data frame allocation information processing unit 910, a physical signal frame multiplexing unit 920 and a radio frequency transmitting unit 930, wherein:

A data frame allocation information processing unit 910, configured to generate transmission data frame allocation information, and sequentially perform channel coding, bit interleaving, and symbol mapping processing on the transmission data frame allocation information;

The physical signal frame multiplexing unit 920 is configured to multiplex the transmission data frame allocation information and service data processed by the above-mentioned channel coding, bit interleaving and symbol mapping into a physical signal frame, and send the physical signal frame to the radio frequency transmitter Unit 930;

The radio frequency transmitting unit 930 is configured to transmit the physical signal frame.

Based on the logical structure shown in FIG. 9 , FIG. 10 is a detailed schematic diagram of a structure of a digital multimedia broadcasting sending end according to an embodiment of the present invention.

In FIG. 10 , most of the module functions are commonly used functional modules in the field, and their functions are not described here.

其中N_MUX为交织块的长度为144，交织后的输出序列为：

则z′_n＝z_R(n)，其中R(n)可按照下列算法求得：However, the convolutional coding bit interleaving and constellation mapping module 101 completes the channel coding, bit interleaving and symbol mapping of the transmission data frame allocation information of the sending end. In the 36-bit system information shown in Table 2, the first 6 bits of information c0- c5 forms the distribution control information of the logical frame. The logical frame framing subframe allocation physical layer signal frame module 102 multiplexes the system information symbols after symbol mapping with other pilot information and service information, and according to the allocation control information of the logical frame (that is, c0 in the aforementioned Table 2 -c5 bits) perform subframe allocation and physical layer signal framing operations on the logical signal frame, wherein the channel coding uses a 1/4 convolutional code with a constraint length of 7, and the octal generator polynomial corresponding to the encoder of the convolutional code is : 133, 171, 145, 133, the initial value of the shift register is all "0". Each of the 36 systematic information shown in Table 2 is independently convolutionally encoded. The low bit of the system information bit stream comes first, that is, c ₀ comes first. Among them: the system information after convolutional encoding adopts bit interleaving, and the interleaving is carried out in units of interleaving blocks. The interleaving algorithm is as follows: Let the input sequence before interleaving be

Where N _MUX is the length of the interleaving block is 144, and the output sequence after interleaving is:

Then z′ _n ＝z _R(n) , where R(n) can be obtained according to the following algorithm:

q＝s/4-1。where, p(0)=0, p(i)=(5×p(i-1)+q) mod s, (i≠0),

q=s/4-1.

The system information is fixed in QPSK mapping mode. The bit streams v ₀ , v ₁ , and v ₂ L after bit interleaving are mapped to QPSK symbol streams for transmission, and power normalization factors are added to various symbol mappings to make the average power of various symbol mappings converge. The power normalization factor β has been included in the constellation diagram, when QPSK mapping $\mathrm{\β}=\sqrt{2}.$

The embodiment of the present invention also proposes a digital multimedia broadcast receiving end. FIG. 11 is a schematic structural diagram of a digital multimedia broadcast receiving end according to an embodiment of the present invention.

As shown in Figure 11, the digital multimedia broadcasting receiver includes a transmission data frame allocation information parsing unit 1110 and a service data receiving unit 1120, wherein:

The transmission data frame allocation information analysis unit 1110 is used to receive the transmission data frame allocation information generated by the digital multimedia broadcasting sending end, and analyze the transmission data frame allocation information to determine the working period of receiving service data and not receiving service data non-working period;

The service data receiving unit 1120 is configured to receive service data corresponding to transmission data frame allocation information during the working period, and not receive service data when not in the working period.

Based on the logical structure shown in FIG. 10 , FIG. 12 is a detailed schematic diagram of the structure of a digital multimedia broadcast receiving end according to an embodiment of the present invention.

In FIG. 12 , most of the module functions are commonly used functional modules in the field, and their functions are not described here.

However, the timing and frequency synchronization module 202 utilizes the beacon signal in the subframe structure of Fig. 2 and Fig. 3 to complete time and frequency synchronization; the channel estimation and equalization module 203 utilizes the pilot signal in the received signal to complete channel estimation and equalization; the transmission data The frame allocation information symbol extraction module 204 module extracts the demodulated data symbols carrying the system information shown in Table 2; the deinterleaving and convolution decoding module 205 performs convolution decoding on the symbol information; in the decoded 36-bit system information Control bit information required for logical frame allocation is extracted.

It can be understood that in the multi-carrier digital broadcasting system based on OFDM, the transmission of the transmission data frame allocation information that plays a controlling role can effectively control the processing of the receiver, and can conveniently reduce the working time of the receiver and reduce energy consumption. the goal of. The method is applicable to fixed terminals and/or mobile terminals in satellite broadcasting and terrestrial wireless broadcasting systems.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (24)

1. A method for transmitting data in digital multimedia broadcasting, comprising the following steps: The digital multimedia broadcasting sending end generates transmission data frame allocation information, and sends the transmission data frame allocation information to the digital multimedia broadcasting receiving end, and the digital multimedia broadcasting receiving end selectively selects from the transmission data frame allocation information according to the transmission data frame allocation information The digital multimedia broadcasting sender receives service data. 2. The method for transmitting data in digital multimedia broadcasting according to claim 1, wherein the digital multimedia broadcasting is digital audio broadcasting or digital video broadcasting. 3. The method for transmitting data in digital multimedia broadcasting as claimed in claim 1, wherein said digital multimedia broadcasting is digital audio broadcasting; wherein said transmission data frame allocation information is sent to a digital multimedia broadcasting receiving terminal comprising the following step: The digital multimedia broadcasting sending end sequentially performs channel coding, bit interleaving and symbol mapping processing on the transmission data frame allocation information; The digital multimedia broadcasting sending end multiplexes the transmission data frame allocation information after the above channel coding, bit interleaving and symbol mapping processing with the service data into a physical signal frame, and sends the physical signal frame to the digital multimedia broadcasting receiving end . 4. The method for transmitting data in digital multimedia broadcasting as claimed in claim 3, wherein the transmission data frame allocation information after the above-mentioned channel coding, bit interleaving and symbol mapping processing is multiplexed with the service data Frames for physical signals include the following steps: Composing the transmission data frame allocation information after the above channel coding, bit interleaving and symbol mapping processing with the service data into a logical frame; Mapping the logical frame into a physical signal frame and sending it; Wherein 4 described physical signal frames form a physical superframe, and each physical signal frame includes 4 physical subframes, and each physical subframe includes 1 beacon symbol and Sn OFDM symbols; The 4 consecutive logical frames form a logical superframe, each logical frame includes 4 consecutive logical subframes, and each physical subframe includes 1 beacon symbol and Sn OFDM symbols. 5. The method for transmitting data in digital multimedia broadcasting as claimed in claim 4, wherein each OFDM symbol comprises bits c0～c35; in: c ₀ ~ c ₁ represent the position of the current physical layer signal frame; c ₂ ~ c ₃ represent the current subframe position; c ₄ ~ c ₅ represent the subframe allocation method; c ₆ ~ c ₇ represent the modulation mode of the transmission data frame allocation information; c ₈ ~ c ₉ represent the modulation mode of service data; c ₁₀ ~ c ₁₁ represent the layered modulation indication of service data; c ₁₂ indicates that the coding of business data adopts the indication of uniform protection; c ₁₃ ~ c ₁₄ represent the LDPC code rate of business data; c ₁₅ ~ c ₁₆ represent the LDPC code rate of business data; c ₁₇ ~ c ₂₆ means to keep Rfa; c ₂₇ ~c ₂₉ represent the CRC check digit; c ₃₀ to c ₃₅ represent reserved Rfu. 6. The method for transmitting data in digital multimedia broadcasting as claimed in claim 4 or 5, said mapping a logical frame into a physical signal frame comprises: According to the arrangement sequence of 4 consecutive logical subframes in the logical frame, map the 4 logical subframes in the logical frame to 4 physical subframes in the physical signal frame, where Sn is 56. 7. The method for transmitting data in digital multimedia broadcasting as claimed in claim 4 or 5, said mapping a logical frame into a physical signal frame comprises: Take 8 consecutive logical subframes in every 2 logical frames of 4 consecutive logical frames as a group, interleave the logical subframes in the group, and map the group of interleaved logical subframes into 2 consecutive physical Signal frame, where Sn is 111. 8. The method for transmitting data in digital multimedia broadcasting as claimed in claim 4 or 5, said mapping a logical frame into a physical signal frame comprises: Taking 4 consecutive logical frames as a group, the i-th logical subframe in each logical frame in the group is sequentially mapped to the i-th physical signal frame, where i is 1, 2, 3 or 4. 9. The method for transmitting data in digital multimedia broadcasting as claimed in claim 1, wherein said digital multimedia broadcasting is digital audio broadcasting; The digital multimedia broadcast receiving end selectively receiving service data from the digital multimedia broadcast sending end includes: The digital multimedia broadcasting receiving end determines a working period for receiving service data and a non-working period for not receiving service data according to the transmission data frame allocation information; During the working period, the digital multimedia broadcasting receives service data corresponding to the transmission data frame allocation information, and when not in the working period, the digital multimedia broadcasting does not receive the service data. 10. A system for transmitting data in digital multimedia broadcasting, characterized in that the system includes a digital multimedia broadcasting sending end and a digital multimedia broadcasting receiving end, wherein: The digital multimedia broadcasting sending end is used to generate transmission data frame allocation information, and send the transmission data frame allocation information to the digital multimedia broadcasting receiving end; The DMB receiver is configured to selectively receive service data from the DMB sender according to the transmission data frame allocation information. 11. The system for transmitting data in digital multimedia broadcasting as claimed in claim 10, wherein the digital multimedia broadcasting is digital audio broadcasting; The digital multimedia broadcasting sending end is used to sequentially perform channel coding, bit interleaving and symbol mapping processing on the transmission data frame allocation information, and combine the transmission data frame allocation information after the above channel coding, bit interleaving and symbol mapping processing with the transmission data frame allocation information Multiplexing the service data into physical signal frames, and sending the physical signal frames to the digital multimedia broadcasting receiving end. 12. The system for transmitting data in digital multimedia broadcasting as claimed in claim 11, characterized in that, The digital multimedia broadcasting sending end is used to form a logical frame with the transmission data frame allocation information processed by the above-mentioned channel coding, bit interleaving and symbol mapping and the service data, and map the logical frame into a physical signal frame and send it; Wherein 4 described physical signal frames form a physical superframe, and each physical signal frame includes 4 physical subframes, and each physical subframe includes 1 beacon symbol and Sn OFDM symbols; The 4 consecutive logical frames form a logical superframe, each logical frame includes 4 consecutive logical subframes, and each physical subframe includes 1 beacon symbol and Sn OFDM symbols. 13. The system for transmitting data in digital multimedia broadcasting as claimed in claim 12, wherein each OFDM symbol comprises bits c0-c35; in: c ₀ ~ c ₁ represent the position of the current physical layer signal frame; c ₂ ~ c ₃ represent the current subframe position; c ₄ ~ c ₅ represent the subframe allocation method; c ₆ ~ c ₇ represent the modulation mode of the transmission data frame allocation information; c ₈ ~ c ₉ represent the modulation mode of service data; c ₁₀ ~ c ₁₁ represent the layered modulation indication of service data; c ₁₂ indicates that the coding of business data adopts the indication of uniform protection; c ₁₃ ~ c ₁₄ represent the LDPC code rate of business data; c ₁₅ ~ c ₁₆ represent the LDPC code rate of business data; c ₁₇ ~ c ₂₆ means to keep Rfa; c ₂₇ ~c ₂₉ represent the CRC check digit; c ₃₀ to c ₃₅ represent reserved Rfu. 14. The system for transmitting data in digital multimedia broadcasting according to claim 12 or 13, wherein: The digital multimedia broadcasting sending end is used to map the 4 logical subframes in the logical frame to the 4 physical subframes in the physical signal frame according to the arrangement order of the 4 consecutive logical subframes in the logical frame frame, where Sn is 56. 15. The system for transmitting data in digital multimedia broadcasting according to claim 12 or 13, wherein: The digital multimedia broadcasting sending end is used to take 8 consecutive logical subframes in every 2 logical frames in 4 consecutive logical frames as a group, interleave the logical subframes in the group, and interleave the groups The logical subframe of is mapped to two consecutive physical signal frames, where Sn is 111. 16. The system for transmitting data in digital multimedia broadcasting according to claim 12 or 13, wherein: The digital multimedia broadcasting sending end is used to take 4 consecutive logical frames as a group, and sequentially map the i-th logical subframe in each logical frame in the group to the i-th physical signal frame, where i is 1, 2, 3 or 4. 17. The system for transmitting data in digital multimedia broadcasting as claimed in claim 10, wherein said digital multimedia broadcasting is digital audio broadcasting; The digital multimedia broadcast receiving end is used to determine a working period for receiving service data and a non-working period for not receiving service data according to the transmission data frame allocation information; The service data of the transmission data frame allocation information, when not in the working period, the digital multimedia broadcasting does not receive the service data. 18. A digital multimedia broadcasting sending end, characterized in that it comprises: a data frame distribution information processing unit, a physical signal frame multiplexing unit and a radio frequency transmitting unit, wherein: A data frame allocation information processing unit, configured to generate transmission data frame allocation information, and sequentially perform channel coding, bit interleaving, and symbol mapping processing on the transmission data frame allocation information; A physical signal frame multiplexing unit, configured to multiplex the transmission data frame allocation information and service data after the above-mentioned channel coding, bit interleaving and symbol mapping processing into a physical signal frame, and send the physical signal frame to the radio frequency transmitting unit ; The radio frequency transmitting unit is configured to transmit the physical signal frame. 19. The digital multimedia broadcasting sending terminal according to claim 18, wherein the digital multimedia broadcasting is a digital audio broadcasting, A physical signal frame multiplexing unit, configured to form a logical frame with the transmission data frame allocation information after the above-mentioned channel coding, bit interleaving and symbol mapping processing and the service data, and map the logical frame into a physical signal frame , and send it; where: The 4 physical signal frames form a physical superframe, and each physical signal frame includes 4 physical subframes, and each physical subframe includes 1 beacon symbol and Sn OFDM symbols; The 4 consecutive logical frames form a logical superframe, each logical frame includes 4 consecutive logical subframes, and each physical subframe includes 1 beacon symbol and Sn OFDM symbols. 20. The digital multimedia broadcasting transmitter according to claim 19, wherein each OFDM symbol comprises bits c0-c35; in: c ₀ ~ c ₁ represent the position of the current physical layer signal frame; c ₂ ~ c ₃ represent the current subframe position; c ₄ ~ c ₅ represent the subframe allocation method; c ₆ ~ c ₇ represent the modulation mode of the transmission data frame allocation information; c ₈ ~ c ₉ represent the modulation mode of service data; c ₁₀ ~ c ₁₁ represent the layered modulation indication of service data; c ₁₂ indicates that the coding of business data adopts the indication of uniform protection; c ₁₃ ~ c ₁₄ represent the LDPC code rate of business data; c ₁₅ ~ c ₁₆ represent the LDPC code rate of business data; c ₁₇ ~ c ₂₆ means to keep Rfa; c ₂₇ ~c ₂₉ represent the CRC check digit; c ₃₀ to c ₃₅ represent reserved Rfu. 21. The digital multimedia broadcasting transmitting end as claimed in claim 19 or 20, wherein the physical signal frame multiplexing unit is configured to, according to the order of arrangement of 4 consecutive logical subframes in the logical frame, place the The four logical subframes in the logical frame are mapped to the four physical subframes in the physical signal frame, where Sn is 56. 22. The digital multimedia broadcasting transmitting end as claimed in claim 19 or 20, wherein the physical signal frame multiplexing unit is configured to use 8 consecutive logical frames in every 2 logical frames in 4 consecutive logical frames A subframe is a group, and the logical subframes in the group are interleaved with each other, and the group of interleaved logical subframes is mapped into two consecutive physical signal frames, where Sn is 111. 23. The digital multimedia broadcasting transmitting end as claimed in claim 19 or 20, wherein the physical signal frame multiplexing unit is configured to take 4 consecutive logical frames as a group, and in each logical frame in the group The i-th logical subframe of is mapped to the i-th physical signal frame in turn, where i is 1, 2, 3 or 4. 24. A digital multimedia broadcast receiving end, characterized in that it includes a transmission data frame allocation information analysis unit and a service data receiving unit, wherein: The transmission data frame allocation information analysis unit is used to receive the transmission data frame allocation information generated by the digital multimedia broadcasting sending end, and analyze the transmission data frame allocation information to determine the working period of receiving service data and the period of not receiving service data non-working period; The service data receiving unit is used for the digital multimedia broadcasting to receive service data corresponding to the transmission data frame allocation information during the working period, and not to receive the service data when not in the working period.

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