CN102970269A - Dynamic data sending method for in-band on-channel (IBOC) system based on ear perception - Google Patents

Abstract

The invention discloses a dynamic data sending method for an in-band on-channel (IBOC) system based on ear perception. A digital signal is arranged at different spectrum positions based on an international telecommunications union-radiocommunication (ITU-R) base station (BS).1387-1 psychological acoustics model; and received analog audio quality is analyzed to obtain an ear evaluation level of an audio program under different spectrum positions of the digital signal, so that a relation between each digital signal spectrum position of each frame of signal and a nuclear magnetic resonance (NMR) evaluation level. When the digital signal is sent, the spectrum position of the digital signal corresponding to a specific level is selected, so that a sub carrier number for transmitting the digital signal is instructed; and the digital signal of the dynamically distributed sub carrier number is coupled with an analog signal. On the premise that each frame of data has uniform ear perception, the available spectrum of the digital signal is increased, and the digital signal transmission capacity under a hybrid mode is improved.

Description

Dynamic data sending method based on the IBOC system of auditory perceptual

Technical field

The present invention relates to wireless telecommunication system, relate in particular to the data transmission method for uplink of a kind of in-band on-channel system.

Background technology

Adopt fixing compound mode that the analog and digital signal frequency spectrum is carried out in-band on-channel (In-Band On-Channel, IBOC) transmission in the HD-Radio broadcasting mixed mode.Yet, owing to the spectral bandwidth of FM analog signal along with programme signal changes, the bandwidth excursion is large.Under very large time probability, the boundary bandwidth of analog fm signal bandwidth regulation analog and digital signal frequency spectrum in the mixed mode.In the case, the real-time change of analog signal bandwidth causes occurring a large amount of idle frequency spectrums.Simultaneously, because the shared spectral bandwidth of analog signal is in real-time change, and the digital signal frequency spectrum is placed on same spectrum position regularly, causes the audio quality in the different time sections that people's ear hears to alter a great deal.

Fig. 1 is the frequency spectrum of HD Radio mixed mode, digital signal is placed on the both sides transmission of simulation FM signal, only use 10 frequency spectrum sub-blocks of each main sideband middle distance central subcarrier distal-most end, and distal-most end is numbered ± 546 reference subcarrier, be called the PM frequency band, altogether comprise 382 subcarriers, the band occupancy scope from-198.402～-129.361KHz and 129.361～198.402KHz.In the frequency spectrum-scope of 129.361～129.361KHz keeps to analog signal, can be monophonic signal or stereophonic signal, also may comprise the subsidiary communications authenticated channel.

In the HD Radio system, transmitting terminal is modulated respectively and is generated analog signal and digital signal, and it is synthetic to finish analog and digital signal by synthesizer, system model such as Fig. 2.At this moment, analog signal and digital signal adopt fixing spectrum mode to make up, and namely digital signal is placed on the position apart from the about 130KHz of carrier wave.

The psychoacoustic model that this patent uses is based on the psychoacoustic model of PEAQ algorithm, as shown in Figure 3.The PEAQ algorithm is by the auditory system of imitation people ear, reference signal and test signal are analyzed objective difference grade (the Objective Difference Grade that draws corresponding to audio quality, ODG), this definition is equal to the SDG in the subjective assessment.

After reference signal and test signal were processed through psychoacoustic model respectively, output separately just can calculate a series of model output parameters (Model Output Variables, MOV) via the sensor model characteristic synthetic.At last, be these MOV Parameter Mappings an objective difference grade output by neural network module.

Psychoacoustic model can convert the time-domain signal of audio frequency to basilar memebrane and represent.Basilar memebrane is positioned at cochlea, and the different frequency composition of sound can excite the excitement of its diverse location.By hair cell this excitement is converted into physiological stimulation again, reaches brain by auditory nerve.The concrete computational process of psychoacoustic model is: for the basic version that uses in this patent, audio signal is transformed into frequency domain by the FFT conversion, then simulate external ear and middle ear to the frequency response of sound by the spectral coefficient weighting, again it is mapped to physiology perception territory.

Sensor model is responsible for signal analysis and comprehensive, and purpose is better to simulate the sense quality of people's ear.

Neural net is responsible for MOV parameter that above two modules are calculated and the MOV parameter is mapped to an objective difference grade by neural net.

Yet, owing to the spectral bandwidth of FM analog signal along with programme signal (such as frequency, amplitude) changes, under very large time probability, the boundary bandwidth of analog fm signal bandwidth regulation analog and digital signal frequency spectrum in the standard.In the case, the real-time change of analog signal bandwidth not only causes a large amount of idle frequency spectrums occurring, and the interior audio quality of different time sections that causes people's ear to be heard alters a great deal.

Summary of the invention

In order to overcome the technical problem that exists in the prior art, the present invention increases digital signal and analog signal self adaptation adjusting module in system, will simulate FM signal and digital signal and join together to process.Frequency spectrum by real-time detection analog fm signal, the information of current analog signal is fed back to digital signal processing module, so that digital signal is carried out the auto-adaptive parameter adjustment, reach and improve the system transmissions ability, and make the different periods that the purpose of identical listening quality be arranged.

The dynamic data sending method of the quasi-definite HD-Radio system based on auditory perceptual of the present invention as shown in Figure 4, may further comprise the steps:

The first step, to transmitting terminal simulated audio signal data intercept to be sent, intercepted length is the 4096*n point, is designated as a frame, and wherein n is positive integer, and the signal after the intercepting is reference signal Ref;

Second step, this reference signal is passed through HD Radio modulation /demodulation software phantom, wherein digital signal places the different spectral position, obtain the simulated audio signal group under the different spectral position after the receiving terminal demodulation, simulated audio signal under each spectrum position is a test signal Test_i, and the length of described each test signal is identical with reference signal;

The 3rd step, according to psychoacoustic model ITU-R BS.1387-1 version, and present frame reference signal Ref and each test signal Test_i, calculate the corresponding psychologic acoustics opinion rating of each test signal NMR_i;

The 4th step, select the corresponding reference signal of required NMR opinion rating, according to the corresponding spectrum position of its digital signal Fstart to Fend, the carrier number N in the designation number signal OFDM modulation, wherein, Fstart is spectrum position top, Fend is that spectrum position is terminal, and N=(Fend-Fstart)/Δ f rounds, and Δ f presses the regulation in the HD Radio standard, Δ f=363.4HZ, thus obtain according to the feature of analog signal and the digital signal after dynamically adjusting;

The 5th step with the modulation of simulated audio signal up-conversion, obtained the FM pumping signal, with FM pumping signal and the digital signal coupling of dynamically adjusting, coupled signal was sent.

Wherein the different spectral position of digital signal refers to, digital signal frequency spectrum terminal constant is identical with HD Radio system digits signal spectrum end, is 200KHZ; The top of digital signal frequency spectrum changes, and value is 80KHZ to 130KHZ, interval 2KHZ; The value of i is 1≤i≤num among the Test_i, and described num value is ((130KHZ-80KHZ)/2KHZ)+1.

The computational methods of wherein said psychologic acoustics opinion rating NMR are:

The first step is carried out respectively the time-domain windowed operation to the reference of a frame length and the test signal of input, then carries out N _FThe weighted factor according to each frequency of property calculation of external ear and middle ear filter is followed in some DFT conversion, afterwards the result of DFT conversion is carried out frequency domain weighting, and wherein the characteristic of external ear and middle ear filter is: $W\left(k\right)=-2.184{(k/1000)}^{-0.8}+6.5e^{-0.6{(k/1000-3.3)}^2}-0.001{(k/1000)}^{3.6},$ K is the spectral line count value;

Second step calculates signal difference, and wherein the computational methods of signal difference are: $X_{\mathrm{diff}}\left[k\right]=X_{\mathrm{ref}}\left[k\right]-2\sqrt{X_{\mathrm{ref}}\left[k\right]\·X_{\mathrm{test}}\left[k\right]}+X_{\mathrm{test}}\left[k\right],$ 0≤k≤N _F/ 2, wherein, X _Ref[k] and X _Test[k] is respectively the spectral line value after the DFT conversion of reference signal and test signal, and k is the spectral line count value;

The 3rd step, reference signal and the test signal of frequency domain are transformed into the Bark territory, the transformational relation in its frequency domain and Bark territory is: z=B (k)=7*asinh (k/650), and wherein, k is frequency domain spectral line count value, B (k) represents frequency domain to the transformational relation in Bark territory, z represents the Bark territory, and the data after the conversion are equally divided into 109 Bark territory subbands, finds boundary value corresponding to each Bark territory subband, again frequency domain is changed in the boundary value contravariant, the inverse transformation relational expression is: k=B ^-1(z)=650*sinh (z/7), wherein B ^-1(z) represent the Bark territory to the transformational relation of frequency domain, find boundary value corresponding to frequency domain, thereby frequency domain data is divided into 109 frequency domain subbands;

The 4th step is respectively with X _RefThe spectral line energy addition that comprises in [k] each frequency domain subband obtains the masking threshold Ehs[m of each frequency domain subband], wherein m is sub band number, m=1 ... 109;

The 5th step is respectively with X _DiffThe spectral line energy addition that comprises in [k] each frequency domain subband obtains the sample noise Ebn[m of each frequency domain subband], wherein m is sub band number, m=1 ... 109;

The 6th goes on foot, and masking threshold and the sample noise weighting of each frequency domain subband is average, calculates the NMR of whole frame data, and its computational methods are: $\mathrm{NNR}=10\log 10(\frac{1}{n}*\frac{1}{109}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}\underset{m=1}{\overset{109}{\mathrm{\Σ}}}\frac{\mathrm{EbN}[p,m]}{g[p,m]*\mathrm{EhS}[p,m]}),$ G[m wherein] be the weighting of masking threshold, expression formula is: $g\left[m\right]=\left\{\begin{array}{cc}{10}^{-3/10}& m\≤48\\ {10}^{m/16}& m>48\end{array}\right..$

Can be further understood by following detailed description and accompanying drawings about advantage of the present invention and method.

Description of drawings

Accompanying drawing described herein is used to provide a further understanding of the present invention, consists of the application's a part, and illustrative examples of the present invention and explanation thereof are used for explaining the present invention, do not consist of improper restriction of the present invention.In the accompanying drawings:

Fig. 1 is the spectrogram of mixed mode (Hybrid);

Fig. 2 is the HD Radio system diagram of the U.S.;

Fig. 3 is the psychoacoustic model algorithm block diagram;

Fig. 4 is the IBOC system data sending method block diagram that the present invention drafts.

Embodiment

Below in conjunction with accompanying drawing preferred embodiment of the present invention is elaborated, thereby so that advantages and features of the invention can be easier to be it will be appreciated by those skilled in the art that protection scope of the present invention is made more explicit defining.

The dynamic data that Fig. 4 shows according to the IBOC system based on auditory perceptual of the present invention sends block diagram.With reference to Fig. 4, may further comprise the steps based on the dynamic data sending method of the IBOC system of auditory perceptual:

The first step, to transmitting terminal simulated audio signal data intercept to be sent, intercepted length is the 4096*n point, is designated as a frame, and wherein n is positive integer, and the signal after the intercepting is reference signal Ref;

Second step, this reference signal is passed through HD Radio modulation /demodulation software phantom, wherein digital signal places the different spectral position, obtain the simulated audio signal group under the different spectral position after the receiving terminal demodulation, simulated audio signal under each spectrum position is a test signal Test_i, and the length of described each test signal is identical with reference signal;

The 3rd step, according to psychoacoustic model ITU-R BS.1387-1 version, and present frame reference signal Ref and each test signal Test_i, calculate the corresponding psychologic acoustics opinion rating of each test signal NMR_i;

The 4th step, select the corresponding reference signal of required NMR opinion rating, according to the corresponding spectrum position of its digital signal Fstart to Fend, the carrier number N in the designation number signal OFDM modulation, wherein, Fstart is spectrum position top, Fend is that spectrum position is terminal, and N=(Fend-Fstart)/Δ f rounds, and Δ f presses the regulation in the HD Radio standard, Δ f=363.4HZ, thus obtain according to the feature of analog signal and the digital signal after dynamically adjusting;

The 5th step with the modulation of simulated audio signal up-conversion, obtained the FM pumping signal, with FM pumping signal and the digital signal coupling of dynamically adjusting, coupled signal was sent.

Wherein the different spectral position of digital signal refers to, digital signal frequency spectrum terminal constant is identical with HD Radio system digits signal spectrum end, is 200KHZ; The top of digital signal frequency spectrum changes, and value is 80KHZ to 130KHZ, interval 2KHZ; The value of i is 1≤i≤num among the Test_i, and described num value is ((130KHZ-80KHZ)/2KHZ)+1.

The computational methods of wherein said psychologic acoustics opinion rating NMR are:

The first step is carried out respectively the time-domain windowed operation to the reference of a frame length and the test signal of input, then carries out N _FThe weighted factor according to each frequency of property calculation of external ear and middle ear filter is followed in some DFT conversion, afterwards the result of DFT conversion is carried out frequency domain weighting, and wherein the characteristic of external ear and middle ear filter is: $W\left(k\right)=-2.184{(k/1000)}^{-0.8}+6.5e^{-0.6{(k/1000-3.3)}^2}-0.001{(k/1000)}^{3.6},$ K is the spectral line count value;

Second step calculates signal difference, and wherein the computational methods of signal difference are: $X_{\mathrm{diff}}\left[k\right]=X_{\mathrm{ref}}\left[k\right]-2\sqrt{X_{\mathrm{ref}}\left[k\right]\·X_{\mathrm{test}}\left[k\right]}+X_{\mathrm{test}}\left[k\right],0\≤k\≤N_F/2,$ Wherein, X _Ref[k] and X _Test[k] is respectively the spectral line value after the DFT conversion of reference signal and test signal, and k is the spectral line count value;

The 3rd step, reference signal and the test signal of frequency domain are transformed into the Bark territory, the transformational relation in its frequency domain and Bark territory is: z=B (k)=7*asinh (k/650), and wherein, k is frequency domain spectral line count value, B (k) represents frequency domain to the transformational relation in Bark territory, z represents the Bark territory, and the data after the conversion are equally divided into 109 Bark territory subbands, finds boundary value corresponding to each Bark territory subband, again frequency domain is changed in the boundary value contravariant, the inverse transformation relational expression is: k=B ^-1(z)=650*sinh (z/7), wherein B ^-1(z) represent the Bark territory to the transformational relation of frequency domain, find boundary value corresponding to frequency domain, thereby frequency domain data is divided into 109 frequency domain subbands;

The 4th step is respectively with X _RefThe spectral line energy addition that comprises in [k] each frequency domain subband obtains the masking threshold Ehs[m of each frequency domain subband], wherein m is sub band number, m=1 ... 109;

The 5th step is respectively with X _DiffThe spectral line energy addition that comprises in [k] each frequency domain subband obtains the sample noise Ebn[m of each frequency domain subband], wherein m is sub band number, m=1 ... 109;

The 6th goes on foot, and masking threshold and the sample noise weighting of each frequency domain subband is average, calculates the NMR of whole frame data, and its computational methods are: $\mathrm{NNR}=10\log 10(\frac{1}{n}*\frac{1}{109}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}\underset{m=1}{\overset{109}{\mathrm{\Σ}}}\frac{\mathrm{EbN}[p,m]}{g[p,m]*\mathrm{EhS}[p,m]}),$ G[m wherein] be the weighting of masking threshold, expression formula is: $g\left[m\right]=\left\{\begin{array}{cc}{10}^{-3/10}& m\≤48\\ {10}^{m/16}& m>48\end{array}\right..$

The above; it only is one of the specific embodiment of the present invention; but protection scope of the present invention is not limited to this; any those of ordinary skill in the art are in the disclosed technical scope of the present invention; variation or the replacement that can expect without creative work all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range that claims were limited.

Claims (3)

1. based on the dynamic data sending method of auditory perceptual IBOC system, it is characterized in that, may further comprise the steps:

The first step, to transmitting terminal simulated audio signal data intercept to be sent, intercepted length is the 4096*n point, is designated as a frame, and wherein n is positive integer, and the signal after the intercepting is reference signal Ref;

Second step, this reference signal is passed through HD Radio modulation /demodulation software phantom, wherein digital signal places the different spectral position, obtain the simulated audio signal group under the different spectral position after the receiving terminal demodulation, simulated audio signal under each spectrum position is a test signal Test_i, and the length of described each test signal is identical with reference signal;

The 3rd step, according to psychoacoustic model ITU-R BS.1387-1 version, and present frame reference signal Ref and each test signal Test_i, calculate the corresponding psychologic acoustics opinion rating of each test signal NMR_i;

The 4th step, select the corresponding reference signal of required NMR opinion rating, according to the corresponding spectrum position of its digital signal Fstart to Fend, the carrier number N in the designation number signal OFDM modulation, wherein, Fstart is spectrum position top, Fend is that spectrum position is terminal, and N=(Fend-Fstart)/Δ f rounds, and Δ f presses the regulation in the HD Radio standard, Δ f=363.4HZ, thus obtain according to the feature of analog signal and the digital signal after dynamically adjusting;

The 5th step with the modulation of simulated audio signal up-conversion, obtained the FM pumping signal, with FM pumping signal and the digital signal coupling of dynamically adjusting, coupled signal was sent.

2. method according to claim 1 is characterized in that, the different spectral position of digital signal refers in the described step 2, and digital signal frequency spectrum terminal constant is identical with HD Radio system digits signal spectrum end, is 200KHZ; The top of digital signal frequency spectrum changes, and value is 80KHZ to 130KHZ, interval 2KHZ; The value of i is 1≤i≤num among the Test_i, and described num value is ((130KHZ-80KHZ)/2KHZ)+1.

3. method according to claim 1 is characterized in that, the production method of NMR grade may further comprise the steps in the described step 3:

The first step is carried out respectively the time-domain windowed operation to the reference of a frame length and the test signal of input, then carries out N _FThe weighted factor according to each frequency of property calculation of external ear and middle ear filter is followed in some DFT conversion, afterwards the result of DFT conversion is carried out frequency domain weighting, and wherein the characteristic of external ear and middle ear filter is: $W\left(k\right)=-2.184{(k/1000)}^{-0.8}+6.5e^{-0.6{(k/1000-3.3)}^2}-0.001{(k/1000)}^{3.6},$ K is the spectral line count value;

Second step calculates signal difference, and wherein the computational methods of signal difference are: $X_{\mathrm{diff}}\left[k\right]=X_{\mathrm{ref}}\left[k\right]-2\sqrt{X_{\mathrm{ref}}\left[k\right]\·X_{\mathrm{test}}\left[k\right]}+X_{\mathrm{test}}\left[k\right],0\≤k\≤N_F/2,$ Wherein, X _Ref[k] and X _Test[k] is respectively the spectral line value after the DFT conversion of reference signal and test signal, and k is the spectral line count value;

The 3rd step, reference signal and the test signal of frequency domain are transformed into the Bark territory, the transformational relation in its frequency domain and Bark territory is: z=B (k)=7*asinh (k/650), and wherein, k is frequency domain spectral line count value, B (k) represents frequency domain to the transformational relation in Bark territory, z represents the Bark territory, and the data after the conversion are equally divided into 109 Bark territory subbands, finds boundary value corresponding to each Bark territory subband, again frequency domain is changed in the boundary value contravariant, the inverse transformation relational expression is: k=B ^-1(z)=650*sinh (z/7), wherein B ^-1(z) represent the Bark territory to the transformational relation of frequency domain, find boundary value corresponding to frequency domain, thereby frequency domain data is divided into 109 frequency domain subbands;

The 4th step is respectively with X _RefThe spectral line energy addition that comprises in [k] each frequency domain subband obtains the masking threshold Ehs[m of each frequency domain subband], wherein m is sub band number, m=1 ... 109;

The 5th step is respectively with X _DiffThe spectral line energy addition that comprises in [k] each frequency domain subband obtains the sample noise Ebn[m of each frequency domain subband], wherein m is sub band number, m=1 ... 109;

The 6th goes on foot, and masking threshold and the sample noise weighting of each frequency domain subband is average, calculates the NMR of whole frame data, and its computational methods are $\mathrm{NNR}=10\log 10(\frac{1}{n}*\frac{1}{109}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}\underset{m=1}{\overset{109}{\mathrm{\Σ}}}\frac{\mathrm{EbN}[p,m]}{g[p,m]*\mathrm{EhS}[p,m]}),$ G[m wherein] be the weighting of masking threshold, expression formula is: $g\left[m\right]=\left\{\begin{array}{cc}{10}^{-3/10}& m\≤48\\ {10}^{m/16}& m>48\end{array}\right..$

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