CN102299891B - Multi-service graded transmission signal modulation and demodulation method and system - Google Patents

Abstract

The invention discloses a multi-service graded transmission signal modulation and demodulation method and a system, relating to the technical field of digital signal transmission. The method comprises the following steps: A1, processing data flow with high priority; A2, processing data flow with low priority; and A3, respectively filling a result for processing the data flow with the high priority and a result for processing the data flow with the low priority to a data frame to be transmitted. Through differential modulation for the data flow with the high priority, one additional path of service transmission is realized under without influencing the property of a transmission service; and in addition, more flexible multi-path service transmission can be realized by using time division multiplex or frequency division multiplex, based on the scheme of the invention.

Description

The signal modulation/demodulation method of Multi-service graded transmission and system

Technical field

The present invention relates to digital signal transmission technique field, particularly a kind of signal modulation/demodulation method of Multi-service graded transmission and system.

Background technology

China's Digital Television Integral is in the period of accelerated development, and three kinds of transmission meanss (cable tv broadcast, ground digital radio broadcasting and digital satellite broadcasting) are all saved up strength to start out.Wherein, terrestrial DTV is because wide coverage, popularity are high, on the outskirts of a town and the radio and television propagation aspect of rural area there is important function.Terrestrial DTV not only becomes the important engineering that country meets people's entertainment life, and its industry development prospect is Worth Expecting quite also.For example, in Hong Kong, Digital Terrestrial Television Broadcast in December, 2007, starts to adopt Chinese digital television broadcasting DMB-T/H standard broadcast program.

Digital Television Terrestrial Broadcasting is a kind of system of broadband wireless transmission, is faced with the frequency selective fading being caused by multipath channel.In order to resist this decline, orthogonal frequency division multiplexi (Orthogonal Frequency Division Multiplexing, OFDM) channel is divided into some orthogonal sub-channels, high-speed data signal is converted to parallel low speed sub data flow, be modulated on every sub-channels and transmit.Signal bandwidth on every sub-channels is all much smaller than the correlation bandwidth of channel, and therefore every sub-channels all can be similar to and regard flat fading as, thereby can eliminate this frequency selective fading.Just because of OFDM, aspect the decline of contrary frequency selectivity, there is unique advantage, it be widely used with various wireless transmitting systems in, for example WIMAX, WLAN.At present, there are three kinds of conventional OFDM technology, the OFDM of Cyclic Prefix (CP-OFDM), the OFDM of zero padding (ZP-OFDM), the OFDM of Domain Synchronous (TDS-OFDM).Wherein, TDS-OFDM is by time domain and frequency domain mixed processing, realized simply and easily quick code word and caught and sane synchronous tracking, become the core technology of Chinese ground digital television broadcast standard, formed and Europe, autonomous core technology that day multi-transceiver technology is different.In addition, transmit diversity is also a kind of technology that can greatly improve digital tv ground broadcasting performance.Utilize space-frequency coding, introduce time domain relevant with spatial domain between different antennae transmits, comprehensive utilization time domain and spatial domain two-dimensional signal realize transmit diversity, can from the integral body of system, improve communication quality and the quantity of multidiameter fading channel simultaneously.

Through fast development in recent years, the range of application of Digital Terrestrial Television Broadcast is more and more wider, and its business providing still be take the television services of fixed reception as main.But in current broadcasting service demand, new business is constantly emerged in large numbers.For example, the portable set for movements such as mobile phone, PDA, notebook computers provides TV program or data message service.Broadcast when therefore, needing to support high definition television and this two kinds of different business of mobile TV during the broadcast system of new generation of our design.High definition TV (High Definition Television, HDTV) is a kind of new television services, and the twice left and right that its horizontal and vertical definition is existing-quality television, is furnished with multichannel surround sound.Tri-kinds of resolution format of display of existing HDTV are respectively: 720P (1280 * 720, line by line), 1080i (1440 * 1080, interlacing) and 1080P (1920 * 1080, line by line), need higher transmission rate.Mobile TV refers to can be with technology or the application of move mode TV reception with all, this has just comprised other loose impediments such as bus, mobile phone, wherein 800 * 480 display resolution has been the highlighted mobile TV of high definition, and its transmission rate is relatively low.

So support is similar to HDTV (High-Definition Television) and mobile TV is this, need to realize the hierarchical transmission of the multiple business with different transmission rates and condition of acceptance.The method that realizes this transmission has a variety of, and for example, by the method for hierarchical modulation, but its receiver complexity when separated two kinds of business is higher, also has plenty of by dividing time/frequency source block, but causes the capacity loss of system.

Summary of the invention

(1) technical problem that will solve

The technical problem to be solved in the present invention is: how in the situation that do not affect the performance of transport service, the transmission of realization increase by one tunnel business.

(2) technical scheme

For solving the problems of the technologies described above, the invention provides a kind of signal modulating method of Multi-service graded transmission, comprise the following steps:

A1: the data flow to high priority is processed;

A2: the data flow to low priority is processed;

A3: the result of the Data Stream Processing of the result of the Data Stream Processing of described high priority and described low priority is filled to respectively in Frame to be sent.

Preferably, steps A 1 specifically comprises the following steps:

A11: the data flow of described high priority is carried out to preliminary treatment, to obtain high priority symbols waiting for transmission;

A12: use described high priority symbols to the basic sequence of upper a group to carrying out differential modulation, to obtain the basic sequence pair of current group;

A13: to the basic sequence of described current group when carrying out sky or space-frequency coding, to obtain the time-domain training sequence to be sent of each transmitting antenna.

Preferably, steps A 2 specifically comprises the following steps:

A21: the data flow of described low priority is carried out to preliminary treatment, to obtain low-priority symbols waiting for transmission;

A22: described low-priority symbols is carried out to space-frequency coding, to obtain block of frequency domain data to be sent;

A23: described block of frequency domain data is carried out to inversefouriertransform, to obtain the time-domain data blocks to be sent of each transmitting antenna.

Preferably, steps A 3 specifically comprises the following steps:

A31: the time-domain data blocks to be sent of described each transmitting antenna is filled to respectively in the Frame to be sent of each transmitting antenna;

A32: the time-domain training sequence to be sent of described each transmitting antenna is filled to respectively in the Frame to be sent of each transmitting antenna, and before being positioned at described time-domain data blocks to be sent.

Preferably, described preliminary treatment comprises: carry out successively interweave, chnnel coding and mapping.

Preferably, the span of the transmitting number of described transmitting antenna is for being more than or equal to 1.

The signal demodulating method that the invention also discloses a kind of Multi-service graded transmission, comprises the following steps:

B1: the time-domain training sequence in current data frame and upper one group of basis sequence, to carrying out differential ference spiral, are obtained to high priority symbols;

B2: described high priority symbols is carried out to rectification, to obtain the data flow of high priority;

B3: calculate current group of basis sequence according to described upper one group of basis sequence and described high priority symbols, and carry out channel estimating according to described current group of basis sequence, to obtain channel condition information;

B4: according to described channel condition information, the time-domain data blocks in described Frame is carried out to coherent demodulation, to obtain low-priority symbols, more described low-priority symbols is carried out to rectification, to obtain the data flow of low priority.

Preferably, described rectification comprises: the demapping of carrying out successively, channel-decoding and deinterleaving.

The signal modulating system that the invention also discloses a kind of Multi-service graded transmission, comprising:

High priority processing module, processes for the data flow to high priority;

Low priority processing module, processes for the data flow to low priority;

Packing module, for being filled to respectively Frame to be sent by the result of the Data Stream Processing of the result of the Data Stream Processing of described high priority and described low priority.

The signal demodulating system that the invention also discloses a kind of Multi-service graded transmission, comprising:

Differential ference spiral module, for to the time-domain training sequence of Frame and upper one group of basis sequence to carrying out differential ference spiral, obtain high priority symbols;

Demodulation module, for described high priority symbols is carried out to rectification, to obtain the data flow of high priority;

Channel estimation module, for calculating current group of basis sequence according to described upper one group of basis sequence and described high priority symbols, and carries out channel estimating according to described current group of basis sequence, to obtain channel condition information;

Coherent demodulation module, for according to described channel condition information, the time-domain data blocks of described Frame being carried out to coherent demodulation, to obtain low-priority symbols, then carries out rectification to described low-priority symbols, to obtain the data flow of low priority.

(3) beneficial effect

The present invention is by carrying out differential modulation to the data flow of high priority, in the situation that do not affect the performance of transport service, realized the transmission that increases by a road business, in addition, on the basis of this programme, also can pass through time division multiplexing or frequency division multiplexing, realize the transmission of multi-channel service.

Accompanying drawing explanation

Fig. 1 is according to the flow chart of the signal modulating method of the Multi-service graded transmission of one embodiment of the present invention;

Fig. 2 is the signal frame structure schematic diagram of two transmitting antenna TDS-OFDM systems of using in the signal modulating method shown in Fig. 1;

Fig. 3 carries out the method flow diagram of signal demodulation to the signal modulating method shown in Fig. 1;

Fig. 4 is to be under 100Hz environment at channel 1 and Doppler frequency shift, and in the Multi-service graded transmission method that the embodiment of the present invention proposes, a kind of high-priority data (being called for short high-level data in figure) adopts BPSK, lower-priority data (being called for short low level data in figure) to adopt the performance of BER of TDS-OFDM system of two transmitting antennas and the performance of BER comparison diagram of the TDS-OFDM system of the two transmitting antennas of traditional 16QAM modulation of 16QAM;

Fig. 5 is to be under 100Hz environment at channel 1 and Doppler frequency shift, the embodiment of the present invention propose Multi-service graded transmission method in a kind of high-priority data (being called for short high-level data in figure) adopt 4QPSK, lower-priority data (being called for short low level data in figure) to adopt the performance of BER of TDS-OFDM system of two transmitting antennas and the performance of BER comparison diagram of the TDS-OFDM system of traditional 64QAM modulation pair transmitting antennas of 64QAM;

Fig. 6 is to be under 20Hz environment at channel 2 and Doppler frequency shift, the embodiment of the present invention propose Multi-service graded transmission method in a kind of high-priority data (being called for short high-level data in figure) adopt BPSK, lower-priority data (being called for short low level data in figure) to adopt the performance of BER of TDS-OFDM system of two transmitting antennas and the performance of BER comparison diagram of the TDS-OFDM system of traditional 16QAM modulation pair transmitting antennas of 16QAM;

Fig. 7 is to be under 20Hz environment at channel 2 and Doppler frequency shift, and in the Multi-service graded transmission method that the embodiment of the present invention proposes, a kind of high-priority data adopts 4QPSK, lower-priority data to adopt the performance of BER comparison diagram of the performance of BER of TDS-OFDM system and the TDS-OFDM system of the two transmitting antennas of traditional 64QAM modulation of the two transmitting antennas of 64QAM.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail.Following examples are used for illustrating the present invention, but are not used for limiting the scope of the invention.

With reference to Fig. 1, the signal modulating method of the Multi-service graded transmission of present embodiment, comprises the following steps:

A1: the data flow to high priority is processed;

A2: the data flow to low priority is processed (in present embodiment, to the processing of the data flow of high priority and be completely independently to the processing of the data flow of low priority);

A3: the result of the Data Stream Processing of the result of the Data Stream Processing of described high priority and described low priority is filled to respectively in Frame to be sent.

Steps A 1 specifically comprises the following steps:

A11: the data flow of described high priority is carried out to preliminary treatment, with obtain high priority symbols waiting for transmission [... d _td _t+1d _t+2d _t+3], wherein

(k is subcarrier sequence number), N _dthe length of high-priority data piece; In present embodiment, described preliminary treatment comprises: carry out successively interweave, chnnel coding and mapping, described in to interweave can be convolutional interleave or block interleaving etc., described mapping can be QAM modulation or PSK modulation etc.;

A12: use described high priority symbols to the basic sequence of upper a group to carrying out differential modulation, to obtain the basic sequence pair of current group; Remember that upper one group of basis sequence is to being

n wherein _tbe the length of training sequence, and meet N _t=2N _d.Remember described upper one group of right N of basis sequence _tpoint Fourier be changed to

use described high priority symbols d _t, d _t+1the basic sequence of upper one group, to carrying out differential modulation, is obtained to the basic sequence pair of current group.

A13: to the basic sequence of described current group when carrying out sky or space-frequency coding, to obtain each transmitting antenna, (the number span of described transmitting antenna is for being more than or equal to 1, in present embodiment, number of transmit antennas is 2, but does not limit its protection range) time-domain training sequence to be sent; In TDS-OFDM system, for fear of phase mutual interference between the training sequence of two antennas, carry out channel estimating, in the time of carrying out sky to training sequence or space-frequency coding.Under the strong channel of time selectivity, training sequence is carried out to space-frequency coding, to utilize the frequency domain correlation of channel to realize channel estimating; Under the strong channel of frequency selectivity, training sequence is carried out to Space Time Coding, to utilize the frequency/relativity of time domain of channel to realize channel estimating.

In different coded systems, the differential scheme that this programme proposes is also different.In order to express easily, definition high priority d _t, d _t+1symbol has been spliced into a data block d,

$d={\left\{d\left(k\right)\right\}}_{k=1}^{N_T}=[d_t\left(0\right)...d_t(N_d-1)d_{t+1}\left(0\right)...d_{t+1}(N_d-1)]$

When training sequence is Space Time Coding, the basic sequence of current group is to being:

$\left\{\begin{array}{c}{\tilde{C}}_t\left(t\right)={\tilde{C}}_{t-2}\left(k\right)d\left(k\right)\\ {\tilde{C}}_{t+1}\left(k\right)={\tilde{C}}_{t-1}\left(k\right)d\left(k\right)\end{array}\right.,k=\mathrm{0,1,2},...N_T-1$

Grounding, to carrying out Space Time Coding, is obtained to transmitting antenna Tx ₀t and the training sequence C to be sent of t+1 signal frame _{0, t}, C ₀, _t+1with transmitting antenna Tx ₁t and the training sequence C to be sent of t+1 signal frame _{1, t}, C _{1, t+1}.

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">C</figure-callout>}}_{0,t}\left(k\right)={\tilde{C}}_t\left(k\right)\\ {\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{1,t}\left(k\right)={\tilde{C}}_{t+1}\left(k\right)\\ {\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">C</figure-callout>}}_{0,t+1}\left(k\right)={\left({\tilde{C}}_{t+1}\left(k\right)\right)}^{<figure-callout\; id="1"\; label="*\; C"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">*</figure-callout>}& \\ C_{}{}_{1,t+1}\left(k\right)=-{\left({\tilde{C}}_t\left(k\right)\right)}^{*}\end{array}\right.,k=\mathrm{0,1,2},...N_T-1$

When training sequence is space-frequency coding, the basic sequence of current group is to being:

$\left\{\begin{array}{c}{\tilde{C}}_t\left(k\right)={\tilde{C}}_{t-1}\left(k\right)d\left(k\right)\\ {\tilde{C}}_t(k+1)={\tilde{C}}_{t-1}(k+1)d^{*}\left(k\right)\\ {\tilde{C}}_{t+1}\left(k\right)={\tilde{C}}_{t}d(k+1)\\ {\tilde{C}}_{t+1}(k+1)={\tilde{C}}_t(k+1)d^{*}(k+1)\end{array}\right.,k=\mathrm{0,2,4}...N_T-2$

Grounding, to carrying out space-frequency coding, is obtained to transmitting antenna Tx ₀t and the training sequence C to be sent of t+1 signal frame _{0, t}, C _{0, t+1}with transmitting antenna Tx ₁t and the training sequence C to be sent of t+1 signal frame _{1, t}, C _{1, t+1}.

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">C</figure-callout>}}_{0,t}\left(k\right)=-{\left(C_{1t}(k+1)\right)}^{*}={\tilde{C}}_t\left(k\right)\\ {\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">C</figure-callout>}}_{0,t}(k+1)={\left({\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{1,t}\left(k\right)\right)}^{*}={\tilde{C}}_t(k+1)\\ {\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">C</figure-callout>}}_{0,t+1}\left(k\right)=-{\left({\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{1,t+1}(k+1)\right)}^{*}={\tilde{C}}_{t+1}\left(k\right)\\ {\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">C</figure-callout>}}_{0,t+1}(k+1)={\left({\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{1,t+1}\left(k\right)\right)}^{*}={\tilde{C}}_{t+1}(k+1)\end{array}\right.,k=\mathrm{0,2,4},...N_T-2$

Because differential modulation can cause error code diffusion, for fear of this situation, the every difference interval D of transmitting terminal in this programme _difsignal frame sends known basic sequence pair, as mod (t, D _dif)=0 o'clock,

$\left\{\begin{array}{c}{\tilde{C}}_t\left(k\right)={\stackrel{\&OverBar;}{C}}_0\left(k\right)\\ {\tilde{C}}_{t+1}\left(k\right)={\stackrel{\&OverBar;}{C}}_1\left(k\right)\end{array}\right.,k=\mathrm{0,1,2}...N_T-1$

Wherein,

with

for transmitting terminal and receiving terminal known basic sequence all.

Steps A 2 specifically comprises the following steps:

A21: the data flow of described low priority is carried out to preliminary treatment, with obtain low-priority symbols waiting for transmission [... S _ts _t+1s _t+2s _t+3]; In present embodiment, described preliminary treatment comprises: interweave, encode and shine upon;

A22: described low-priority symbols is carried out to space-frequency coding, to obtain block of frequency domain data to be sent; When t signal frame transmitting, right

carry out space-frequency coding, obtain respectively the block of frequency domain data to be sent of two transmitting antennas, be specially:

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="0"\; label="S"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">S</figure-callout>}}_{0,t}\left(k\right)=S_t\left(k\right)\\ {\mathrm{<figure-callout\; id="0"\; label="S"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">S</figure-callout>}}_{0,t}(k+1)=S_t(k+1)\\ {\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">S</figure-callout>}}_{1,t}\left(k\right)={S_t}^{*}(k+1)\\ {\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">S</figure-callout>}}_{1,t}(k+1)=-{S_t}^{*}\left(k\right)\end{array}\right.$

k＝0，2，4，…N-2

A23: described block of frequency domain data is carried out to inversefouriertransform, to obtain the time-domain data blocks to be sent of each transmitting antenna, (the number span of described transmitting antenna is for being more than or equal to 1, in present embodiment, number of transmit antennas is 2, but does not limit its protection range); Be specially, described block of frequency domain data is carried out to inversefouriertransform, obtain respectively transmitting antenna Tx ₀time-domain data blocks to be sent [... s _{0, t}s _{0, t+1}s _{0, t+2}s _{0, t+3}] and transmitting antenna Tx ₁time-domain data blocks to be sent [... s _{1, t}s _{1, t+1}s _{1, t+2}s _{1, t+3}].

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="0"\; label="s"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">s</figure-callout>}}_{0,t}=\mathrm{idft}\left({\mathrm{<figure-callout\; id="0"\; label="S"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">S</figure-callout>}}_{0,t}\right)\\ {\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_{1,t}=\mathrm{idft}\left({\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">S</figure-callout>}}_{1,t}\right)\end{array}\right..$

Steps A 3 specifically comprises the following steps:

A31: the time-domain data blocks to be sent of described each transmitting antenna is filled to respectively in the Frame to be sent of each transmitting antenna;

A32: with reference to Fig. 2, the time-domain training sequence to be sent of described each transmitting antenna is filled to respectively in the Frame to be sent of each transmitting antenna, and before being positioned at described time-domain data blocks to be sent.

The invention also discloses a kind of method that signal that described signal modulating method is modulated carries out signal demodulation, with reference to Fig. 3, comprise the following steps:

B1: the time-domain training sequence in current data frame and upper one group of basis sequence, to carrying out differential ference spiral, are obtained to high priority symbols; Remember that t-2, t-1, t, t+1 receive data block and be respectively y _t-1, Y _t, Y _t+1, they can be written as:

$\left\{\begin{array}{c}{Y}_{t-2}\left(k\right)={\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t-2}\left(k\right){\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">C</figure-callout>}}_{0,t-2}\left(k\right)+{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t-2}\left(k\right){\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{1,t-2}\left(k\right)\\ Y_{t-1}\left(k\right)={\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t-1}\left(k\right){\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">C</figure-callout>}}_{0,t-1}\left(k\right)+{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t-1}\left(k\right){\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{1,t-1}\left(k\right)\\ Y_t\left(k\right)={\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t}\left(k\right){\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">C</figure-callout>}}_{0,t}\left(k\right)+{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t}\left(k\right){\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{1,t}\left(k\right)\\ Y_{t+1}\left(k\right)={\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t+1}\left(k\right){\mathrm{<figure-callout\; id="0"\; label="C"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">C</figure-callout>}}_{0,t+1}\left(k\right)+{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t+1}\left(k\right){\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">C</figure-callout>}}_{1,t+1}\left(k\right)\end{array}\right.,k=\mathrm{0,1,2}...N_T-1$

The coded system of different training sequences, the differential ference spiral method described in this programme is different.When training sequence is Space Time Coding, receives data block and can be written as:

$\left\{\begin{array}{c}{Y}_{t-2}\left(k\right)={\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t-2}\left(k\right){\tilde{C}}_{t-2}\left(k\right)+{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t-2}\left(k\right){\tilde{C}}_{t-1}\left(k\right)\\ Y_{t-1}\left(k\right)={\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t-1}\left(k\right){{\tilde{C}}_{t-1}}^{*}\left(k\right)-{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t-1}\left(k\right){{\tilde{C}}_{t-2}}^{*}\left(k\right)\\ Y_t\left(k\right)=({\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t}\left(k\right){\tilde{C}}_{t-2}\left(k\right)+{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t}\left(k\right){\tilde{C}}_{t-1}\left(k\right))d\left(k\right)\\ Y_{t+1}\left(k\right)=({\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t+1}\left(k\right){{\tilde{C}}_{t-1}}^{*}\left(k\right)-{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t+1}\left(k\right){{\tilde{C}}_{t-2}}^{*}\left(k\right))d^{*}\left(k\right)\end{array}\right.,k=\mathrm{0,1},...,N_T-1$

The channel variation of supposing adjacent channel is less,

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t-2}\left(k\right)\&ap;{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t-1}\left(k\right)\&ap;{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t}\left(k\right)\\ {\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t-2}\left(k\right)\&ap;{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t-1}\left(k\right)\&ap;{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t}\left(k\right)\end{array}\right.$

The high-priority data symbol stream sending can revert to:

$d\left(k\right)=\frac{1}{2}{\left(Y_{t-2}\left(k\right)\right)}^{*}{Y}_t\left(k\right)+\frac{1}{2}{Y}_{t-1}\left(k\right){\left(Y_{t+1}\left(k\right)\right)}^{*},k=\mathrm{0,1},...,N_T-1$

Differential ference spiral method described in this programme is different.When training sequence is space-frequency coding, receives data block and can be written as:

$\left\{\begin{array}{c}{Y}_{t+1}\left(k\right)={\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t+1}\left(k\right){\tilde{C}}_{t+1}\left(k\right)+{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t+1}\left(k\right){{\tilde{C}}_{t+1}}^{*}(k+1)\\ Y_{t+1}(k+1)={\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t+1}(k+1){\tilde{C}}_{t+1}(k+1)-{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t+1}(k+1){{\tilde{C}}_{t+1}}^{*}\left(k\right)\\ Y_{t+2}\left(k\right)=({\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t+2}\left(k\right){\tilde{C}}_{t+1}\left(k\right)+{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t+2}\left(k\right){{\tilde{C}}_{t+1}}^{*}(k+1))d\left(k\right)\\ Y_{t+2}(k+1)=({\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t+2}(k+1){\tilde{C}}_{t+1}(k+1)-{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t+2}(k+1){{\tilde{C}}_{t+1}}^{*}\left(k\right))d^{*}\left(k\right)\end{array}\right.,k=\mathrm{0,2,4}...N_T-2$

The channel variation of supposing adjacent channel is less,

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t-1}\left(k\right)\&ap;{\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA0000085220890000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{0,t}\left(k\right)\\ {\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t-1}\left(k\right)\&ap;{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t}\left(k\right)\end{array}\right.$

The high-priority data symbol stream sending can revert to:

$d\left(k\right)=\frac{1}{2}{Y_{t-1}}^{*}\left(k\right)Y_t\left(k\right)+\frac{1}{2}{Y}_{t-1}(k+1)Y_t^{*}(k+1),k=\mathrm{0,2,4}...N_T-2$

The data flow of in like manner, carrying in even subcarriers can revert to:

$d(k+1)=\frac{1}{2}{Y}_t^{*}\left(k\right)Y_{t+1}\left(k\right)+\frac{1}{2}{Y}_t(k+1){Y_{t+1}}^{*}(k+1),k=\mathrm{0,2,4}...N_T-2$

B2: described high priority symbols is carried out to rectification, to obtain the data flow of high priority; Described rectification comprises: the demapping of carrying out successively, channel-decoding and deinterleaving;

B3: calculate current group of basis sequence according to described upper one group of basis sequence and described high priority symbols, and carry out channel estimating according to described current group of basis sequence, to obtain channel condition information; After high-priority data symbol stream recovers, can recover to obtain the grounding sequence pair of current group by simple calculating

with

utilize reception signal and the basic sequence of current group with

just can to current demand signal frame the wireless channel of process estimate.Take Space Time Coding as example, receive signal and can be written as:

$\left[\begin{array}{c}{Y}_t\left(k\right)\\ Y_{t+1}\left(k\right)\end{array}\right]=\left[\begin{array}{cc}{\tilde{C}}_t\left(k\right)& {\tilde{C}}_{t+1}\left(k\right)\\ {\left({\tilde{C}}_{t+1}\left(k\right)\right)}^{*}& -{\left({\tilde{C}}_t\left(k\right)\right)}^{*}\end{array}\right]\left[\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t}\left(k\right)\\ {\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA0000085220890000031.png,HDA0000085220890000032.png"\; state="\{\{state\}\}">H</figure-callout>}}_{2,t}\left(k\right)\end{array}\right]$

:

$\left[\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HDA0000085220890000011.png"\; state="\{\{state\}\}">H</figure-callout>}}_{1,t}\left(k\right)\\ {\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA0000085220890000031.png,HDA0000085220890000032.png"\; state="\{\{state\}\}">H</figure-callout>}}_{2,t}\left(k\right)\end{array}\right]=\frac{1}{{\left|{\tilde{C}}_t\left(k\right)\right|}^2+{\left|{\tilde{C}}_{t+1}\left(k\right)\right|}^2}\left[\begin{array}{cc}{\left({\tilde{C}}_t\left(k\right)\right)}^{*}& {\tilde{C}}_{t+1}\left(k\right)\\ {\left({\tilde{C}}_{t+1}\left(k\right)\right)}^{*}& -\left({\tilde{C}}_t\left(k\right)\right)\end{array}\right]\left[\begin{array}{c}{Y}_t\left(k\right)\\ Y_{t+1}\left(k\right)\end{array}\right]$

B4: according to described channel condition information, the time-domain data blocks in described Frame is carried out to coherent demodulation, to obtain low-priority symbols, more described low-priority symbols is carried out to rectification, to obtain the data flow of low priority.

The signal modulation/demodulation method that the present invention is directed to the Multi-service graded transmission shown in Fig. 1 and Fig. 3 has carried out Computer Simulation, and main simulation parameter is as shown in table 1.In emulation, two kinds of channel models used are typical wireless multi-path Fading Channel as shown in table 2, and wherein, channel 1 is to be respectively Brazilian A model and the Brazilian B model for field test with channel 2.

Table 1

Symbol rate	7.56M symbol/second
		OFDM subcarrier planisphere	QPSK/16QAM
OFDM sub-carrier number N	3780
		Training sequence length	420
LDPC encoder bit rate	0.6

Table 2

For comparative analysis, simulation result has provided BER (Bit Error Rate, the bit error rate) performance curve of traditional TDS-OFDM system.Fig. 4 is under the environment that is 100Hz at channel 1 and Doppler frequency shift, high-priority data adopts BPSK, lower-priority data to adopt the performance of BER of TDS-OFDM system of two transmitting antennas and the performance of BER comparison diagram of the TDS-OFDM system of the two transmitting antennas of traditional 16QAM modulation of 16QAM, in figure, SNR (Signal Noise Ratio) is signal to noise ratio.Because channel 1 is typical time-selective channel, so training sequence adopts space-frequency coding in emulation.As can be seen from the figure, high-priority data has lower threshold level, can be for supporting mobile service, low complex degree receiver.In addition, the performance of low-priority data stream also very approach traditional TDS-OFDM system, even if difference interval D dif increases, performance loss is very little also.Fig. 5 is under the environment that is 100Hz at channel 1 and Doppler frequency shift, and high-priority data adopts 4QAM, lower-priority data to adopt the performance of BER curve of this programme of 64QAM and the TDS-OFDM scheme of traditional 64QAM modulation.As can be seen from the figure, the performance of low priority traffice and traditional TDS-OFDM's is almost to coincide together.

Under the environment that it is 20Hz that Fig. 6 and Fig. 7 are respectively at channel 2 and Doppler frequency shift, the performance of BER curve of " BPSK+16QAM " and " 4QAM+64QAM " two kinds of application.Now environment is typical frequency-selective channel, so training sequence adopts Space Time Coding in emulation.Simulation result shows this method also still use under frequency-selective channel.

The signal modulating system that the invention also discloses a kind of Multi-service graded transmission, comprising:

High priority processing module, processes for the data flow to high priority;

Low priority processing module, processes for the data flow to low priority;

Packing module, for being filled to respectively Frame to be sent by the result of the Data Stream Processing of the result of the Data Stream Processing of described high priority and described low priority.

The invention also discloses the system that a kind of signal that described signal modulating system is modulated carries out signal demodulation, comprising:

Differential ference spiral module, for to the time-domain training sequence of Frame by upper one group basis sequence to carrying out differential ference spiral, to obtain high priority symbols;

Demodulation module, for described high priority symbols is carried out to rectification, to obtain the data flow of high priority;

Channel estimation module, for calculating current group of basis sequence according to described upper one group of basis sequence and described high priority symbols, and carries out channel estimating according to described current group of basis sequence, to obtain channel condition information;

Coherent demodulation module, for according to described channel condition information, the time-domain data blocks of described Frame being carried out to coherent demodulation, to obtain low-priority symbols, then carries out rectification to described low-priority symbols, to obtain the data flow of low priority.

Above execution mode is only for illustrating the present invention; and be not limitation of the present invention; the those of ordinary skill in relevant technologies field; without departing from the spirit and scope of the present invention; can also make a variety of changes and modification; therefore all technical schemes that are equal to also belong to category of the present invention, and scope of patent protection of the present invention should be defined by the claims.

Claims (7)

1. a signal modulating method for Multi-service graded transmission, is characterized in that, comprises the following steps:

A1: the data flow to high priority is processed;

A2: the data flow to low priority is processed;

A3: the result of the Data Stream Processing of the result of the Data Stream Processing of described high priority and described low priority is filled to respectively in Frame to be sent;

Steps A 1 specifically comprises the following steps:

A11: the data flow of described high priority is carried out to preliminary treatment, to obtain high priority symbols waiting for transmission;

A12: use described high priority symbols to the basic sequence of upper a group to carrying out differential modulation, to obtain the basic sequence pair of current group;

A13: to the basic sequence of described current group when carrying out sky or space-frequency coding, to obtain the time-domain training sequence to be sent of each transmitting antenna;

Steps A 2 specifically comprises the following steps:

A21: the data flow of described low priority is carried out to preliminary treatment, to obtain low-priority symbols waiting for transmission;

A22: described low-priority symbols is carried out to space-frequency coding, to obtain block of frequency domain data to be sent;

A23: described block of frequency domain data is carried out to inversefouriertransform, to obtain the time-domain data blocks to be sent of each transmitting antenna;

Steps A 3 specifically comprises the following steps:

A31: the time-domain data blocks to be sent of described each transmitting antenna is filled to respectively in the Frame to be sent of each transmitting antenna;

A32: the time-domain training sequence to be sent of described each transmitting antenna is filled to respectively in the Frame to be sent of each transmitting antenna, and before being positioned at described time-domain data blocks to be sent.

2. signal modulating method as claimed in claim 1, is characterized in that, described preliminary treatment comprises: carry out successively interweave, chnnel coding and mapping.

3. signal modulating method as claimed in claim 1, is characterized in that, the span of the transmitting number of described transmitting antenna is for being more than or equal to 1.

4. a signal demodulating method for Multi-service graded transmission, is characterized in that, comprises the following steps:

B1: the time-domain training sequence in current data frame and upper one group of basis sequence, to carrying out differential ference spiral, are obtained to high priority symbols;

B2: described high priority symbols is carried out to rectification, to obtain the data flow of high priority;

B3: calculate current group of basis sequence according to described upper one group of basis sequence and described high priority symbols, and carry out channel estimating according to described current group of basis sequence, to obtain channel condition information;

B4: according to described channel condition information, the time-domain data blocks in described Frame is carried out to coherent demodulation, to obtain low-priority symbols, more described low-priority symbols is carried out to rectification, to obtain the data flow of low priority.

5. method as claimed in claim 4, is characterized in that, described rectification comprises: the demapping of carrying out successively, channel-decoding and deinterleaving.

6. a signal modulating system for Multi-service graded transmission, is characterized in that, comprising:

High priority processing module, processes for the data flow to high priority, use described high priority symbols to the basic sequence of upper a group to carrying out differential modulation, to the basic sequence of current group when carrying out sky or space-frequency coding;

Low priority processing module, processes for the data flow to low priority, and described low-priority symbols is carried out to space-frequency coding, and block of frequency domain data is carried out to inversefouriertransform;

Packing module, for the result of the Data Stream Processing of the result of the Data Stream Processing of described high priority and described low priority is filled to respectively to Frame to be sent, the time-domain training sequence to be sent of each transmitting antenna is filled to respectively in the Frame to be sent of each transmitting antenna, and before being positioned at described time-domain data blocks to be sent.

7. a signal demodulating system for Multi-service graded transmission, is characterized in that, comprising:

Differential ference spiral module, for to the time-domain training sequence of Frame and upper one group of basis sequence to carrying out differential ference spiral, obtain high priority symbols;

Demodulation module, for described high priority symbols is carried out to rectification, to obtain the data flow of high priority;

Channel estimation module, for calculating current group of basis sequence according to described upper one group of basis sequence and described high priority symbols, and carries out channel estimating according to described current group of basis sequence, to obtain channel condition information;

Coherent demodulation module, for according to described channel condition information, the time-domain data blocks of described Frame being carried out to coherent demodulation, to obtain low-priority symbols, then carries out rectification to described low-priority symbols, to obtain the data flow of low priority.

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