Method for mixing audio signals, transmitter and receiver for amplitude- and frequency-modulated digital audio broadcast in channel frequency band

FIELD: methods and devices for processing composite audio broadcast signal.

SUBSTANCE: proposed method includes following procedures: analog-modulated part of audio broadcast signal is separated from digital-modulated part of audio broadcast signal; data from analog component of broadcast signal is separated from its digital component to produce mixed output audio signal. Method is also proposed for transferring composite audio broadcast signal that has analog part and digital part to suppress irregular interruptions in reception of mentioned audio broadcast signal by adding modem frames with analog part of broadcast signal which incorporate audio frames presenting digital part of audio broadcast signal.

EFFECT: provision for suppressing irregular interruptions in reception of audio broadcast signal.

25 cl, 4 dwg

 

The present invention relates to methods and devices for processing signals, in particular to methods and devices for suppressing the effects of signal fading, temporary shading or severe deterioration of the channel in the system digital sound broadcasting in the frequency band of the channel.

Digital audio broadcasting (CSV) is a tool for capturing sound with digital quality, which is higher than that of the existing formats of analogue broadcasting. Both AM and FM signals CSV can be transmitted in a hybrid format in which the signal is digitally modulated coexists with passed at present analog AM or FM signal, or in digital format without the analog signal. System CSV in the frequency band of the channel does not require new allocations of spectrum, as each signal CSW transmitted simultaneously with the same spectral mask of an existing distribution of AM or FM channels. Transmission method in a frequency band of the channel contributes to the economy of the spectrum, at the same time allowing broadcasters to offer their present main part of the audience sound with digital quality. It was suggested several principles CSV in the frequency band of the channel.

The use of FM systems CSW in the frequency band of the channel was the subject of several U.S. patents, including patents No. 5465396, 5315583, 5278844 and 5278826. PEFC is dnee time it was proposed, what FM signal CSW in the frequency band of the channel combines carrier with analog modulation with multiple subcarriers of an orthogonal frequency division channels (OCRC), placed in the range of from about 129 kHz to 199 kHz from the center frequency FM, both above and below the spectrum occupied by the main FM carrier with analog modulation.

One principle AM in CSV in the frequency band of the channel, described in U.S. patent No. 5588022, is a method of simultaneous transmission of analogue and digital signals in a standard channel, AM broadcast. Using this principle is transmitted amplitude-modulated RF signal having the first frequency spectrum. Amplitude-modulated radio frequency signal includes the first carrier, the modulated analog signal program. Simultaneously transmits multiple signals carrying digitally modulated within a frequency band, which encompasses the first frequency spectrum. Each carrier signal with digital modulation is modulated digital signal program. The first group of signals carrying digital modulation lies within the first frequency spectrum and are modulated in quadrature with the first carrier signal. The second and third groups of signals carrying digital modulation lie outside of the first frequency spectrum and are modulated both in-phase and in to the atature with the first carrier signal. Many of bearing used for transferring the information transmitted by orthogonal frequency division channels (OCRC).

Radio signals are susceptible irregular fading or shades that you need to pay attention in broadcasting systems. Usually FM radios suppress the influence of fading or partial shading transition from full stereo sound mode mono sound. Achieved some degree of suppression, so as to record information, which modulates subcarriers requires a higher signal-to-noise ratio for demodulation to obtain the desired level of quality than for monaural information, which is the main band of frequencies. There are, however, some shading, which is completely “destroy” the heaviest band of frequencies and, thus, create a break in reception of a sound signal. System CSV in the frequency band of the channel should be made so as to suppress even these violations radio last type with conventional analog broadcasting, at least where such violations radio are irregular and do not continue more than a few seconds. In order to accomplish this suppression system digital audio broadcasting may use the transmission of the main signal vasani is together with excess signal, moreover, the excess signal is delayed by a specified temporary value, of the order of several seconds, relative to the main broadcast signal. The corresponding delay is introduced in the receiver to delay the received main signal broadcast. The receiver can detect the deterioration of the characteristics in the main channel of the broadcast that are fading or shadowing in the radio frequency signal before they will be perceived by the listener. In response to this detection is delayed redundant signal can temporarily replace the distorted main audio signal, acting as a “gap filler”, when the main signal is distorted or not available. It provides a blending function for a smooth transition from the primary audio signal to the delayed redundant signal.

The idea of mixing signal CSW transmission systems in the frequency band of the channel with analog detained in time sound signal (AM or FM signal) is described in co-pending application for U.S. patent transferred with the right to joint use of the System and method of suppressing irregular interruptions in the audio broadcasting system” No. 08/947902, filed October 9, 1997, corresponding to the published patent application WO 99/20007. Implementation, implied in this proposal assumes that the analog signal can be delayed real-time gross simple hardware, processing the signal in real time, where you can precisely control the relative delay.

In publishing Brian W., Kroeger et al., "Compatibility of FM Hybrid In-Band On-Channel (IBOC) System for Digital Audio Broadcasting", IEEE Transactions on Broadcasting, US, New York, Vol. 3, no.4, December 1997, describes the mixing of analog and digital signals in the system of digital sound broadcasting in the frequency band of the channel.

It is desirable, however, to control the delay that can be performed using digital signal processors, programmable non-real-time. The present invention describes a method of processing signals CSV containing the delay function explode and mixing, which can be implemented using integrated circuits programmable digital signal processor operating in non-real time.

The invention

The present invention provides a method of processing a composite digital audio broadcast to suppress irregular interrupt signal reception digital sound broadcasting. How is that a separate part of the analog modulation signal of the digital audio broadcast from the part of the digitally modulated signal of the digital audio broadcast, create a first set of audio frames having symbols representing the portion of the analog modulation signal digital zvukovoj the broadcast, and create a second set of audio frames having symbols representing the portion of the digitally modulated signal digital sound broadcasting. The first set of audio frames is then merged with a second set of audio frames to create a mixed audio output signal.

In addition, the invention includes a method of transferring composite digital audio broadcast with the analog part and the digital part, to suppress irregular interrupt signal reception digital sound broadcasting. How is that place the symbols representing the digital portion of the signal, digital audio broadcasting, multiple audio frames, create the set of modem frames, with each modem frame contains the specified number of audio frames, and add a sync signal frame to each modem frame. Modem frames are then passed along with the analog part of the signal of the digital audio broadcasting and the analog part is delayed by a time delay corresponding to a whole number of modem frames. The invention also includes radio receivers and transmitters, which processes the signals in accordance with the above-described method.

Brief description of drawings

Figure 1 presents the block diagram of the transmitter CSV, which can transmit si is Nala digital sound broadcasting in accordance with the present invention;

figure 2 presents the block diagram of a radio receiver capable of mixing analog and digital portions of the signal of the digital sound broadcasting in accordance with the present invention;

figure 3 presents a time chart showing the phasing of the audio frame with the symbol synchronization frame, and

4 shows a functional block diagram depicting the implementation of mixing for hybrid FM receivers CSV.

Description of the preferred embodiments

As shown in the drawings, figure 1 is a block diagram of the transmitter 10 CSV, which can transmit signals to digital sound broadcasting in accordance with the present invention. The signal source 12 generates a signal which is transferable. The signal source may take various forms, such as analog signal programs and/or digital information signal. Based on the digital signal processor modulator 14 processes the signal source in accordance with various methods of signal processing that are not part of the present invention, such as source coding, interleaving and forward error correction, to generate in-phase and quadrature components of the complex signal baseband frequencies on lines 16 and 18. These components are shifted up cha is the Thoth, filtered and interpolated to a higher sampling rate in block 20 of the Converter with increasing frequency. He creates a digital sampling frequency fdin the signal of the intermediate frequency fFCon line 22. D / a Converter 24 converts the signal to an analog signal on line 26. The intermediate frequency filter 28 filters out spurious low-frequency components in the spectrum of the sample signal to generate a signal of the intermediate frequency fFCon line 30. The local oscillator 32 produces a signal fgon line 34, which is mixed with the intermediate frequency signal on line 30 by means of the mixer 36 to generate sum and difference signals on line 38. The total signal and other unwanted intermodulation components and noise are suppressed by the filter 40 suppression of specular channel to create a modulated signal fncarrier on the line 42. The amplifier 44 high power then sends this signal to the antenna 46.

Figure 2 presents the block diagram of the radio made in accordance with the present invention. The signal CSW is received by the antenna 50. Band-pass filter 52 with a preliminary selection of skips interest in the band, including the useful signal with a frequency fnbut suppresses the signal of the mirror channel with what astotal f n-2fFC(for lo transmission signal at a low lateral frequency). Low noise amplifier 54 amplifies the signal. The amplified signal is mixed in mixer 56 with the signal fglo, supplied through line 58 custom oscillator 60. This creates total (fn+fg) and difference (fn-fgsignals on line 62. The intermediate frequency filter 64 passes a signal of the intermediate frequency fFCattenuates signals with frequencies outside the frequency band of interest modulated signal. Analog-to-digital Converter 66 works by using the clock signal to generate digital samples on line 68 with a frequency fd. Digital Converter 70 with decreasing frequency shifts the frequency filters and thins signal to generate in-phase and quadrature signals with a lower sampling frequency on lines 72 and 74. Based on the digital signal processor demodulator 76 then performs additional signal processing to produce an output signal on line 78 to the output device 80.

In the absence of a digital portion of an audio signal CSW (for example, when the channel is initially configured or when there is a violation of the radio when ZEV) analog backup sound AM or FM signal is applied to the sound output. When it becomes on the orienting signal CSW, based on the digital signal processor, the demodulator performs the function of mixing for smooth weakening and ultimately remove the analog backup signal during mixing in the sound signal CSV, so that the transition minimally visible.

Similar mixing occurs during the disturbances in the radio channel, which distorts the signal CSW. Distortion is detected within the delay time explode using detection error control cyclic redundancy code. In this case, the analog signal is gradually added to the output audio signal, at the same time weakening the signal CSV, so that the sound mixing becomes fully analog, when there is distortion of the signal CSW on the audio output. In addition, the receiver outputs the analog audio signal whenever no signal is present CSV.

In one proposed design of the receiver digital audio broadcasting analog backup signal is detected and demodulated, creating a stream of samples of the audio signal with a frequency of 44.1 kHz (stereo in the case of FM, which can be further mixed to mono or blocked at low signal-to-noise ratio). The sampling frequency of 44.1 kHz synchronized with the clock pulses of the reference clock receiving the ICA. The data decoder also generates a sampling of the audio signal with a frequency of 44.1 kHz, but the sampling is synchronized with the flow modem data, which is based on the reference clock of the transmitter. Minor deviations of the frequency of clock pulses 44.1 kHz between the transmitter and the receiver to prevent a direct and simple mixing of samples of the analog signal, because the content of the audio signal in the end slowly shifts over time. Requires therefore some way of phasing samples the analog signal and the audio signal CSW.

The modulator of the transmitter allocates the digital information in serial modem frames 82, as shown in figure 3. The symbol synchronization frame 84 is transmitted at the beginning of each modem frame, duplicate, for example, every 256 characters CRC. The symbol synchronization frame indicates the phasing between analog and digital signals, as shown in figure 1. The duration of the modem frame in the preferred embodiment contains characters exactly 16 audio frames 86 (a period of approximately 371,52 MS). The leading edge of the symbol synchronization frame spoziroval with the cutting edge of audio frame 0 (modulo 16). Equivalent to the leading edge of the analog backup signal is transmitted simultaneously with the cutting edge of the symbol synchronization frame. the ADR encoded data, which contains the equivalent of compressed information for the audio frame 0, was actually passed in front of the modem frame that was transmitted previously separated exactly by the amount of delay explode. Equivalent to the leading edge is defined as the temporal sampling of the analog (FM) signal, which corresponds to the first sample of the symbol synchronization frame or the beginning of the modem frame. Delay diversity is a given integer multiple of the number of modem frames. Delay diversity is significantly more delay to the processing made by the digital processing system CSV, with the delay greater than 2.0 and preferably in the range of 3.0 to 5.0 C.

Sampling the analog and digital audio signals can be spairani through interpolation sampling (oversampling) one of the streams of audio signals, so that it becomes synchronized with the other. If the clock receiver 44.1 kHz should be used for the audio output signal of the DAC, then it's best to perform oversampling digital stream of audio signals for mixing with an analog sound signal, which is synchronized with the reference clock of the receiver. This is done as in the method of mixing is shown in functional block diagrams figure 4. Realizareaconexiunii, shown in figure 4, is designed to be compatible with computer processing of samples of the signal in real time. For example, any delay is implemented by counting samples of the signal instead of measuring the absolute time or calculations of periodic clock pulses. This includes the “marking” of samples of the signal, where it is necessary to perform the phasing. The implementation so it can be processed slabosvyazannykh a subset of the digital signal processor in which a valid group forwarding and processing of samples of the signal. The only restrictions then are the requirements for the integrated absolute delay processing together with appropriate labelling of samples of the signal to eliminate uncertainty during the time window processing.

4 shows a functional block diagram of the relevant part of the hybrid FM receiver CSV. Hybrid AM-receiver CSV has almost identical functionality. To simplify the description of the invention in figure 4, the paths of the signals of the programs shown in solid lines, and the paths of control signals - dotted lines. Input signal for mixing on the line 100 is integrated modem baseband signal (sampled with a frequency of 744187,5 kHz for FM in the preferred embodiment). The block 102 is sabrejet, this signal is divided into a tract 104 analog FM signal and the tract 106 digital signal. This is done by using filters to separate the signals. In the path of the analog FM signal is processed FM detector 108 that produces a sequence of stereo audio output signal, diskretisierung with a frequency of 44.1 kHz on line 110. This FM stereo may also have its own algorithm mixing in mono mode, similar to that already implemented in car radios to improve the signal-to-noise due to crosstalk between the stereo channels. For convenience, as shown in block 112, FM striopallidodentate is FM audio frames of 1024 samples of the audio stereo signal, using the clock generator 114 FM audio frames. These frames can then be transferred and processed blocks. FM audio frames on line 116 are then mixed in block 118 from the re-fazirovannye digital audio frames when they are present. The control signal mixing is fed to the line 120 to control the mixing of the audio frames. The control signal mixing adjusts the relative number of analog and digital portions of the signal that is used to generate the output signal. The control signal is of a mixing usually sensitive on some measurement of degradation of the digital part of the signal. The method used to generate the control signal mixing, is not part of the present invention, however, in the previously mentioned application No. 08/947902 describes how to create a control signal mixing.

The input baseband signal is also divided into digital path 106 through their own filters to separate it from the analog FM signal. Block 122 indicates that the signal CSW main strip “marked” phasing FM audio frame after appropriate correction for different delay processing filters separating device. This marking allows the subsequent measurement for phasing so that the digital audio frames can be re-spairani with FM audio frames. The demodulator 124 digital signal outputs frames of compressed and encoded data to the decoder 126 for subsequent conversion in the audio frames of the digital signal. In the demodulator of the digital signal, as expected, also is the modem detection signal, synchronization and any decoding forward error correction required for the intended decoded and enclosed in a frame of bits at its output. In addition, the digital signal demodulator detects the symbol synchronization frame and measures the time delay relative to armirovannykh samples of the base band, fazirovannykh with FM audio frames. This measured time delay, as shown by block 128, identifies the time offset of the audio frame of the digital signal relative to the time of the FM audio frame with a resolution sampling frequency 744187,5 kHz (i.e. resolution ±672 NS during the period of the audio frame). There remains, however, uncertainty about which audio frame gaziruetsya (i.e. from 0 to 15). This uncertainty is easily solved by means of a designation of each audio frame of the digital signal sequence number from 0 to 15 (modulo 16) during the period of modem frame. Practically it is recommended that, in order to identify the used sequence numbers with a much larger module (for example, 8-bit sequence numbers indicate audio frames of the digital signal from 0 to 255), allowing temporary “surplus” for processing, at the same time, however, preventing the uncertainty in the phase of modem frames during the delay explode.

The resolution of uncertainty regarding audio frames, described in the previous paragraph, can also be simplified encoding of the exact number of audio frames in a modem frame.

This requires a modification in the audio encoder, so that the audio frames with variable length are not allowed to cover g is unity modem frame with two sides. This simplification can eliminate the need for consistent notation audio frames, as these frames (for example, 16, 32 or 64 audio frame) appear in known fixed sequence within each modem frame.

After the error phasing measured and known, this error is eliminated by re-phasing the audio frames of the digital signal exactly at this value. This is done in 2 stages. During the first stage of the re-phasing eliminates fractional error δ violations phasing of the sample, using the fractional interpolator 130 samples of the audio signal. In fact, the fractional interpolator samples of the audio signal has been just the oversampling of samples of the digital audio signal with a delay δ. In the next step, re-phasing eliminates a part of the error delay sampling. This is done by passing samples of the audio signal from the re-fazirovannoi fractional part through the buffer 132 FIFO type (first-come, first-out). After these samples are read from the buffer FIFO type, they re-adjusted, as represented by block 134, so again fazirovannye audio frames of the digital signal synchronized with the FM audio frames. The buffer FIFO type introduces significant is th delay which includes a delay explode minus the latency introduced by the encoder. Re fazirovannye audio frames of the digital signal on line 136 is then mixed with the FM audio frames on line 116 to create a mixed audio output signal on line 138.

In the receiver of figure 4 block 122 illustrates a means for marking the first of many audio frames, representing the part of the amplitude modulation signal CSW, a symbol representing the phase of a second set of audio frames representing the part with digital modulation (CM) signal CSW. Block 128 illustrates a means for measuring the displacement between the first and second sets of audio frame to generate the error signal. Block 134 illustrates a means for correcting the first set audio frames in response to the error signal and illustrates the means for delaying the first set of audio frames before combining the first set of audio frames with the second set of audio frames to create a mixed audio output signal. Block 102 illustrates a means for creating a first set of audio frames representing the part with analog modulation (AM) signal CSW. Block 66 figure 2 illustrates the means for sampling part of the AM signal CSW to generate symbols for the first set of audio frames. Block 132 Il is ustrinum means for placing a given number of audio frames from the first set audio frames in each modem frame from the first set of modem frames. Block 112 illustrates a means for placing a given number of audio frames from the second set of audio frames in each modem frame from the second set of modem frames.

Although the uncertainty of frames can be resolved only on the boundaries of the modem frame, the fractional part (δ) of samples of the audio signal temporarily offset of symbol synchronization, frame, relative to the marked sampling baseband digital signal should be measured at the beginning of each FM audio frame. This allows you to smooth out the fractional value δ delay interpolation to minimize the jitter of the clock frequency when oversampling. Dynamically changing values δ errors in time proportional to the error of the reference oscillator clock pulses. For example, if the error of the reference oscillator clock pulse is 10 pulse/min relative to the clock of the transmitter CSV, the fractional error δ the selection will change on the full sample of beep approximately every 2, 3 C. Similarly, changes δ over time one modem frame is approximately one-sixth of the sample audio signal. This step size can be very large for high-quality sound systems. Smoothing δ therefore, it is desirable to minimize this jitter t is Kutovoy frequency.

This particular implementation of the mixing allows the demodulator CSV, decoder and fractional interpolator samples to work without strict time limits up until these processes are completed within the time delay explode, so the audio frames of the digital signal present in the time of mixing.

The mixing of the audio signals of the present invention includes a delay explode necessary for all systems CSW in the frequency band of the channel. The preferred implementation includes the phasing of the sampling frequency of the audio signal with the frequency of the clock pulses 44.1 kHz, derived from the reference clock source to the receiver. Described here is a specific implementation includes the use of programmable digital signal processors, working in real time, as opposed to hardware implementation in real-time. Phasing should match the virtual clock generator CSV with a frequency of 44.1 kHz, which is synchronized with the transmitted digital signal CSW. Although the clocks of the transmitter and receiver is nominally designed for a sampling frequency of the audio signal is 44.1 kHz, the physical tolerances of the clocks fail, which should b the th corrected in the receiver. Method of phasing includes interpolation (oversampling) audio signal CSW to fix the clock.

Although the present invention has been described based on its preferred option for implementation, for specialists in this field of technology it is clear that can be done various modifications to the described embodiment of implementation within the scope of the invention defined in the attached claims.

1. The method of processing a composite signal of the digital sound broadcasting to suppress irregular interrupt signal reception digital sound broadcasting (CSV), namely, that separate part with analog modulation (AM) signal CSW from parts with digital modulation (CM) signal CSV, create a first set of audio frames having symbols representing the part of the AM signal CSV, create a second set of audio frames having symbols representing the part of the CM signal CSW, combine the first set of audio frames with the second set of audio frames, thus regulate the relative amount of parts with AM and part C The CM signal CSW, which are used to form an audio output signal, moreover, the presence of part of the CM signal CSW remove the part with the AM signal CSW during their mixing in the audio output signal CSW and the case of detecting the distortion part of the CM signal CSW part of the AM signal CSW gradually mixed with the audio output signal, at the same time weakening the part of the CM signal CSW sound output signal by mixing becomes fully part of the AM signal CSW.

2. The method according to claim 1, characterized in that it further mark the second set of audio frames, each with a symbol that represents a phase of a second set of audio frames.

3. The method according to claim 1, characterized in that it further measure the offset between the first and second sets of audio frame to generate the error signal, adjusting the second set audio frames in response to the error signal and delay adjusted second set of audio frames before mentioned Association of the first set of audio frames with the second set of audio frames to create a mixed audio output signal.

4. The method according to claim 1, characterized in that when the first set of audio frames, representing the part of the AM signal CSW, discretizing part of the AM signal CSW to generate symbols for the first set of audio frames and place specified number of audio frames from the first set audio frames in each modem frame from the first set of modem frames.

5. The method according to claim 4, characterized in that when creating the second set of audio frames, representing the part of the CM signal CSW place mentioned specified number is the number of audio frames from the second set of audio frames in each modem frame from the second set of modem frames.

6. The method according to claim 1, characterized in that the detection of the distortion part of the CM signal CSW control using a cyclic redundancy code part with the CM signal CSW during the period of time delay explode.

7. The method according to claim 1, characterized in that additionally use a first set of audio frames to create the original sound output signal to the said Association.

8. A receiver for processing a composite digital audio broadcast to suppress irregular interrupt signal reception digital sound broadcasting (CSV)containing means for separating a portion from an analog modulation (AM) signal CSW from parts with digital modulation (CM) signal CSW, means for creating a first set of audio frames having symbols representing the part of the AM signal CSW, means for creating a second set of audio frames having symbols representing the part of the CM signal CSW, means for mixing the first set of audio frames with the second set of audio frames, which served to control the mixing sonic frame control signal mixing, which is sensitive to changes in the parameters part of the CM signal CSW, and is governed by the relative number of parts and AM part of the CM signal CSW, which is used to generate audible what about the output.

9. Receiver of claim 8, characterized in that it further comprises means for marking the first of many audio frames symbol representing the phase of a second set of audio frames.

10. Receiver of claim 8, characterized in that it further comprises means for measuring the displacement between the first and second sets of audio frame to generate the error signal, means for correcting the first set audio frames in response to the error signal, and means for delaying the adjusted first set of audio frames before mentioned Association of the first set of audio frames with the second set of audio frames to create a mixed audio output signal.

11. Receiver of claim 8, wherein the means for creating a first set of audio frames, representing the part of the AM signal CSV contains means for sampling part of the AM signal CSW to generate symbols for the first set of audio frames and the means for placing a given number of audio frames from the first set audio frames in each modem frame from the first set of modem frames.

12. The receiver according to claim 11, characterized in that the means for creating a second set of audio frames, representing the part of the CM signal CSW, provides a means to accommodate mentioned the acceptable number of audio frames from the second set of audio frames in each modem frame from the second set of modem frames.

13. Receiver of claim 8, characterized in that it further comprises means for monitoring using a cyclic redundancy code part with the CM signal CSW during the period of time delay explode.

14. The transfer method composite digital audio broadcast with the analog part and the digital part, to suppress irregular interrupt signal reception digital sound broadcasting (CSV), namely, that place the symbols representing digital part of the signal CSW, in many audio frames, create the set of modem frames, with each modem frame contains the specified number of audio frames, add a sync signal frame to each modem frame, and the synchronization signal frame indicates the phasing between analog part and digital part, transmit modem frames and transmit the analog part of the signal CSW after a time delay, the corresponding integer modem frames, while the leading edge of the synchronization signal frame transmit simultaneously with the equivalent cutting edge analog part.

15. The method according to 14, characterized in that it further represent each of the audio frames sequence number.

16. The method according to item 15, wherein the sequence numbers contain the number of rooms, covering a wide range of modem frames

17. A transmitter for transmitting the composite signal of the digital audio broadcasting with analog part and digital part, to suppress irregular interrupt signal reception digital sound broadcasting (CSV)containing a modulator for placement of symbols representing digital part of the signal CSW, in many audio frames to create a variety of modem frames, with each modem frame contains the specified number of audio frames, and to add a sync signal frame to each modem frame, and the synchronization signal frame indicates the phasing between analog part and digital part, and the antenna for modem transmission frames for transmission of analog signal CSV after a time delay corresponding to a whole number of modem frames, while the leading edge of the synchronization signal frame is transmitted simultaneously with the equivalent cutting edge analog part.

18. The transmitter 17, characterized in that it further comprises means for designating each of the audio frames sequence number.

19. The transmitter p, characterized in that the sequence numbers contain the number of rooms, covering a wide range of modem frames.

20. The transmitter 17, wherein the audio frames of the first set of audio frames are of variable length and each modem frame contains the specified number of audio frames from the first set of audio frames.

21. A radio receiver for processing a composite digital audio broadcasting (CSV)containing the delimiter signals, which divides the signal path of the analog signal path of the digital signal, and in the path of the analog signal is processed by the detector, creating a first set of audio frames having symbols representing part with amplitude modulation (AM) signal CSW, the digital signal demodulator, which outputs the frames of compressed and encoded data to the decoder for converting the second set of audio frames having symbols representing part with digital modulation (CM) signal CSV, and performs detection of the modem signal, synchronization, and decoding forward error correction, and a unit for mixing the first set of audio frames with the second set of audio frames, which served to control the mixing of the audio frame control signal mixing, which is sensitive to changes in the parameters part of the CM signal CSW, and is governed by the relative number of parts and AM part of the CM signal CSW, which is used to generate the audio output signal.

22. The receiver according to item 21, characterized in that it further comprises a unit for marking the first of many audio frames fazirovannym-audio frame after correction for different delay processing filters separator.

23. The receiver according to item 21, characterized in that it further comprises means for measuring the displacement between the first and second sets of audio frame to generate the error signal, means for correcting the first set audio frames in response to the error signal, and means for delaying the adjusted first set of audio frames before mentioned Association of the first set of audio frames with the second set of audio frames to create a mixed audio output signal.

24. The receiver according to item 21, wherein the processor to create a first set of audio frames, representing the part of the AM signal CSV contains means for sampling part of the AM signal CSW to generate symbols for the first set of audio frames and the means for placing a given number of audio frames from the first set audio frames in each modem frame from the first set of modem frames.

25. The receiver according to paragraph 24, wherein the demodulator to generate a second set of audio frames, representing the part of the CM signal CSW, contains a means for placing the aforementioned specified number of audio frames from the second set of audio frames in each modem frame from the second set of modem frames.



 

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FIELD: generation of analog and digital signals for.

SUBSTANCE: method for generating signal of weakened amplitude for simultaneous transfer, meant for simultaneous transfer of digital radio broadcast and analog radio broadcast signal, contains stages of generation of primary error signal, generation on basis of primary weakened signals of final signal for simultaneous transmission. Generator of weakened amplitude signal for simultaneous transmission, meant for simultaneous transfer of digital and analog radio broadcast signals contains final signal generator for simultaneous transmission, advance weakening cascade, containing primary signal generator for simultaneous transfer, meant for generation, on basis of aforementioned digital and analog broadcast signals, of primary error signal and primary amplitude weakening block, meant for weakening of at least one of aforementioned radio broadcast signals.

EFFECT: generation of stable signal for simultaneous transfer with maximal level of signal for analog and digital transferred signals, allowing to increase primary service area for analog and digital system.

2 cl, 4 dwg

FIELD: communications engineering, in particular, systems for communication inside vehicles or in close proximity of vehicles.

SUBSTANCE: in accordance to one of variants, system for transferring information from first position inside or in close proximity of a vehicle to second position inside a vehicle, where vehicle has a conductive metallic structure, containing a remote block, containing first communication equipment, provided with sensor, exciter block, containing second communication equipment and excitation means, connected due to conductivity to metallic structure of vehicle, while first communication equipment receives information in first position, realizes modulation of signal using this information, receives electromagnetic field in metallic structure of vehicle through sensor, excitation device performs extraction of current at the expense of conductivity from metallic structure of vehicle and production of current signal, second communication equipment receives that signal, demodulates and transfers information to second position, in such a way realizing transfer of information from first position to second position by wireless communication method.

EFFECT: creation of excitation system and excitation methods for providing communication inside or in close proximity of vehicles.

8 cl, 18 dwg

FIELD: methods for identification of changed in repeatedly broadcasted database.

SUBSTANCE: in accordance to the method data is produced in fragments, document is received which contains information about fragments, information is analyzed, and fragments are received repeatedly in accordance to aforementioned information.

EFFECT: possible listening of repeated broadcasting with minimal processing of data, detection of change of any data element and determining of location where the change is described.

4 cl, 2 dwg

FIELD: technology for receiving audio broadcasting signals.

SUBSTANCE: method for receiving frequency-modulated signal of digital audio broadcasting, including first and second sets of sub-carriers respectively in upper and lower side band of radio channel, contains steps of mixing of digital audio broadcasting signal with heterodyne signal, letting through of intermediate frequency signal through band filter, determining presence of distortion of upper or lower side band of digital audio broadcasting signal, application of frequency shift to heterodyne signal for ensuring change of frequency of signal of intermediate frequency, at which band filter removes sub-carriers in distorted upper or lower side band. The receiver realizes the method.

EFFECT: minimized influence of first neighboring interferences in received signals.

2 cl, 5 dwg

FIELD: communications engineering.

SUBSTANCE: in accordance to the invention, ground-based digital video-broadcasting network contains content provider and three transmitters. Integrated receiver/decoder (IRD) moves in a zone near transmitters. By transmitting service information as a part of network information table at data level, transmitters provide transmission parameter information in their output signals as data for signaling transmission parameters (TPS) at physical level. Aforementioned TPS information includes one bit, which defines to which type of network the signal is related, and information, which denotes whether the signal contains data flows, quantized in time. That information is used by (IRD) both in scanning a signal or (IRD) initialization by parameters, required for detection of service at 1-2 levels of open systems (OSI), and for canceling selection of signals as candidates for relay service transfer. Because transmission parameter information is transmitted more often and at lower OSI level compared to network information table, (IRD) may efficiently make decisions: whether the signal is fitting for relay service transfer, or whether it is a signal of interest.

EFFECT: reduction of energy consumption in mobile receiver.

5 cl, 5 dwg, 11 tbl

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