Method and device for reducing the ratio of maximum power to the average in the digital broadcasting systems

 

The invention relates to electronic signal processing, in particular to the signal processing to reduce the ratio of maximum power to the average radio signals. Technical result achieved is the reduction of the ratio of maximum power to the average electronic signals with orthogonal frequency seal. A method of reducing the ratio of maximum power to the average radio signal is that modulate the set of subcarriers with a set of vectors of data symbols to obtain a first modulated signal, limit its value, demodulateur it, modulate the set of subcarriers using a pre-distorted vectors of data symbols to obtain a second modulated signal, limit its value, reduce intermodulation components in the second limited modulation signal. The transmitters provide a means for implementing the above method. 4 C. and 24 C.p. f-crystals, 16 ill.

The technical field to which the invention relates

The invention relates to electronic signal processing, in particular to the signal processing to reduce the relations s (CSV) is a means of providing digital audio signal quality, which is superior to analog broadcast formats prior art. Band - ear (UPVC) CSV with FM can be implemented in a hybrid format, with the last digital modulation signal coexists with the broadcast at this time, the analog FM signal, or in a fully digital format, in which the analog FM signal is eliminated. For WPVC not require new spectrum allocations because each CSV signal simultaneously transmit in the same spectral distribution pattern of the FM channels in accordance with the prior art. UPVC contributes to the saving of the spectrum, providing a broadcasting companies to provide digital quality audio signal to your listeners.

The advantages of digital transmission of a sound signal: high signal quality with less noise and a wider dynamic range compared to FM radio channels of the prior art. First hybrid format can be adapted to the receivers of the prior art have been able to continue to receive analog FM signal, and when this new UPVC receivers can decode the digital signal. After some time, when there will be a lot UPVC receivers CSV, besause is to provide a stereo digital audio signal along with the data actually quality level of the CD-ROM, with the simultaneous transmission of the FM signal according to the prior art. The task of fully digital UPVC CSV with FM is to provide a stereophonic sound signal actually quality level of the CD-ROM, together with a data channel, with a bandwidth of approximately 200 KB/s, depending on the interference level at this station.

One of the proposed systems UPVC broadcast the world Cup uses a set of orthogonal multiplexed with the frequency separation (OMCR) bearing for transmission of the digital signal. OMCR signal consists of the sum of multi-carrier modulated at different and rownorzednych frequencies, orthogonal with respect to each other. Therefore, different subcarriers do not interfere with each other. The magnitude of the transmitted signal in such a system sometimes has a very high peak value. Therefore, linear power amplifiers used in transmitters UPVC CSV should work with significant power losses to out-of-band power was below the specified limits. As a result of these conditions require the use of very expensive and inefficient amplifiers. In this regard, there is a need to reduce relations method of reducing the ratio of maximum power to the average electronic signals using orthogonal frequency sealing, carried out in such a way that it can be used in systems UPVC CSV the world Cup.

The invention

This invention provides a method of reducing the ratio of maximum power to the average radio signal. How is that modulate the set of subcarriers with a set of vectors of data symbols to obtain a first modulated signal, limit the magnitude of the first modulated signal to obtain a first limited modulated signal, demodulated first limited modulated signal to recover the points of the constellation, pre-distort the vector of data symbols to provide a minimum value for the in-phase and quadrature components to obtain a pre-distorted vectors of character data, modulate the aggregate carrying through pre-distorted vectors of data symbols to obtain a second modulated signal, limit the value of the second modulated signal to obtain a second limited modulated signal and reduce intermodulation components in the second limited modulation signal.

According to alternative variants of the t vectors of the Central characters of data subcarriers while reducing intermodulation components in the second modulated limited signal.

The subject of this invention are also transmitters that implement this method.

List of figures

Fig.1 is a schematic diagram of frequency allocations and relative spectral power density signal components for hybrid signal UPVC CSV with the world Cup;

Fig.2 is a schematic diagram of frequency allocations and relative spectral power density of the signal for all digital signal UPVC CSV the world Cup.

Fig.3 is a simplified block diagram of the transceiver is configured to apply the method of reduction of the ratio of maximum power to the average according to this invention; and

Fig.4 is a graphic representation of one type of implementation constraints, which can be used in the method according to this invention; and

Fig.5 is a schematic representation of the pre-distortion of data characters applied to this invention; and

Fig.6 is a schematic diagram of the method according to this invention as applied to a broadcasting system that uses a hybrid digital audio signal; and

Fig.7 - grafichnogo invention; and

Fig.8 is a graph of simulation results of power spectral densities modulated waveform processed in accordance with this invention, using the limit function according to Fig.4;

Fig.9 - frequency of bit error for different variants illustrated in Fig.8;

Fig.10 is a graph of simulation results of power spectral densities modulated waveform processed in accordance with this invention, a variant, when the high power amplifier uses a feature limitations, illustrated in Fig.7;

Fig.11 - frequency of bit error for different variants illustrated in Fig.10;

Fig.12 is a schematic diagram of the method according to this invention as applied to a transmitter broadcasting a fully digital audio signal; and

Fig.13 is a graph of simulation results of power spectral densities modulated waveform processed in accordance with this invention, variant, using the limit function illustrated in Fig.4;

Fig.14 - frequency of bit error for different variants illustrated in Fig.13;

Fig.15 is a graphical representation of results of modelling the acquisition, option when high power amplifier uses a feature limitations, illustrated in Fig.7;

Fig.16 - frequency of bit error for different variants illustrated in Fig.15.

Information confirming the possibility of carrying out the invention

Fig.1 is a schematic diagram of frequency allocations (spectral location) and relative spectral power density signal components for hybrid signal 10 UPVC CSV with FM according to this invention. The hybrid format includes a standard stereo analog FM signal 12 having a power spectral density, represented by triangular form 14 located in the Central part 16 of the bandwidth of the channel. Power spectral density (MTA) typical analog FM broadcast signal is almost triangular with a decline of about 0.35 dB/kHz from the center frequency. The totality of the past digital modulation rownorzednych subcarriers are placed on both sides of the analog FM signal at the top side 18 and bottom side 20, and is passed together with the analog FM signal. All carriers pass on this power level, which is defined channel pattern 22 Fe is Ty relative to the average characteristics of the spectral power density.

In accordance with one of the modulation techniques some set rownorzednych orthogonal multiplexed with the frequency spacing of subcarriers (OMCR) placed on both sides of the main analog FM signal occupying approximately range from 129 kHz to 199 kHz from the main Central FM frequency that is depicted in the upper side of the strip 18 and the lower side of the strip 20 in Fig.1. In the hybrid system all CSV-power in OMCR-modulated subcarriers in each side band set about -25 dB relative to the main analog FM power. CSV signal is passed on OMCR-subcarriers located on both sides of the analog spectrum. System CSV contains 191 bearing at the top and 191 carrier bottom of the main FM spectrum. Each CSV-modulate subcarriers using quadrature phase shift keying at a symbol rate equal to 344,53125 Hz. In-phase and the quadrature pulse shapes give the taper raised to the power of cosine (excessive time = 7/128) on the fronts to suppress spectral side lobes. This pulse shape gives the spacing of the frequency orthogonal subcarrier equal 363,3728 Hz.

Part of a hybrid signal transmitted digital modulate the ATA UPVC CSV. The levels of the spectral occupancy and relative power density digital signal OMCR-subcarriers in a fully digital format CSV with the designation 24 shown in Fig.2. Depicted on Fig.1 analog FM signal is replaced by an optional group OMCR-subcarriers, called the advanced fully digital signal 26, which is in the Central stripe 28 frequencies. Ravnovesnye OMCR-subcarriers are also in the upper side band 30 and the bottom side 32. The side bands are fully digital format according to Fig.2 wider lateral bands, depicted in Fig.1. The level of spectral power density of the side strips fully digital UPVC signals installed on approximately 10 dB higher than permitted in hybrid side UPVC bands. This provides for a fully digital UPVC signal significant advantages from the point of view of performance. In addition, the spectral power density advanced fully digital signal by about 15 dB below this density in the hybrid side UPVC bands. This fact minimizes or eliminates the problem of interference of the adjacent hybrid or fully digital UPVC signal, and provides add the ical continuation of the hybrid mode, according to which the analog signal, originally occupied the Central range100 kHz, replaced with digital subcarriers low level. On both sides of the low-level bearing are two digital sidebands, which differ from the hybrid mode to the fact that increasing the bandwidth to approximately 100 kHz and to increase power by 10 dB approximately. We offer a fully digital CSW system has 267 bearing in each side band and 559 bearing in the center. Each CSV-modulate subcarriers using quadrature phase manipulation. In-phase and the quadrature pulse shapes give the taper raised to the power of cosine (excessive time = 7/128) on the fronts to suppress spectral side lobes. This pulse shape gives the spacing of the frequency orthogonal subcarrier equal 363,3728 Hz. Graph spectral power density for the transmitted signal must be completely within the digital template ITVC the world Cup.

Fig.3 is a functional block diagram illustrating implementation of the present invention in the transmitter UPVC CSV the world Cup. The generator 34 characters generates the data symbols are quadrature phase-shift keying (CPK), containing Peredovaya the m CSW signal (normalized). This modulation includes the operation of the inverse fast Fourier transform (OBPF) character data to implement OMCR-modulation. To the modulated signal (excess time = 7/128) using a cyclic prefix with the root finite weighing function to the extent of the cosine. The combination OBPF and weighing transaction using compactly supported functions hereinafter referred to as “CSV-modulator”.

The block 38 is the main block, which implements the reduction of the ratio of maximum power to the average. The modulated output signal CSW modulator 36 is sent as an input signal in this block. The output signal of the block 38 is a signal with reduced AMS. For the implementation of the reduction OMS modulated signal is limited in amplitude, as shown by block 40, then demodulated in block 42, and is received by demodulator vectors characters pre-distort, or bind, to obtain the minimum-phase or quadrature components in the block 44. Related characters then modulate in block 46 to obtain a second modulated signal, which is subjected to further restriction in the block 48. This limitation creates unwanted intermodulation SOS and eliminate the block 50 to the signal in the amplifier 52 high power for broadcast via antenna 54.

Fig.4 is a graph illustrating the operation of the limiter, which can be used to perform the functions of the block 40. Limiter set a certain threshold or limit value K1. If the input power is greater than K1, then it at any time unilaterally to limit K1. Because the input signal is normalized, then it ensures that AMS signal at the output of the limiter is equal to K1. The operation of the limiter (for real x) can be illustrated as follows. If the value of the input signal (X) is less than-K1, the output signal of the limiter is set equal to-K1, if the value of the input signal (X) is greater than K1, the output signal of the limiter is set to K1, and if the input signal has a value between-K and K-1, then the output signal equals the input signal. K1 equal 1,58, means that the ratio of maximum power to the average for this mode of operation is set to 4 dB.

Limited modulated signal is then applied to CSV-demodulator 42. In CSV-demodulator converts the operation of applying the cyclic prefix and weighing using a compactly supported function, first performed on the modulated samples. Then run a quick convert the functions and FFT referred to as “CSV-demodulator”.

Then the points of the constellation vector of data symbols recovered by demodulation operation, connect, so they have a minimum in-phase and quadrature components, in order to reduce distortion caused by the implementation of unilateral restrictions on the limiter. To accomplish this, linking each OMCR-vector characters during this operation forcibly placed in a particular zone 54, 56, 58 or 60 according to Fig.5 - around point of the constellation. In Fig.5 points 62, 64, 66 and 68 of the constellation have the expected in-phase and quadrature value A. Some fixed part a, denoted as F, defines the area in which associated data characters. Linking each element OMCR-vector of symbols is illustrated below.

If the input symbol (x): x=a+bi, where a is the in-phase component, and b is the quadrature component of the output signal (y) is defined as: y=a’+b’i, where a’ and b’ is determined as follows:

If abs(a)<=FAnd

if a<0, a’=-(FA)

or a’=FAnd

or a’=and

If abs(b) <=FA

if b<0, b’=-(FA)

or b is alaysia points of the constellation symbols force have at least a minimum value, equal to some given part of the expected in-phase and quadrature values.

Then the associated vector of symbols modulate using CSV modulator 46, and the modulated output signal is passed through a limiter 48. The limiter 48 uses the limit function that is similar to that depicted in Fig.4, but has a threshold value K2. Thereby it is guaranteed that the signal at the output of the limiter 48 is OMMS equal to K2, because the input signal is normalized.

To the transmitted signal fit within the hybrid template UPVC with FM, the signal is brought to the block 50 by zero subcarriers are not transmitting data. The distortion due to this development is minimal. In a preferred implementation of the system UPVC CSV the world Cup as the actual process involves a unilateral restriction of subcarriers which do not transmit the data for all inactive channels (outside of the two side petals) to zero.

Fig.6 is a schematic diagram illustrating a method of reducing OMS according to this invention. Block 70 illustrates that the input vector characters OMCR CSV data subcarrier injected into CSV-demodulator 72. Thus obtained on line 72 of the first modulated signal to limit the output signal on line 78, then demodulated in block 80, to restore the points of the constellation vector character data on line 82. Restored point constellation pre-distort the block 84 and thus link them, so they have a specified minimum value of the in-phase and quadrature components according to the above. CSV-modulator 86 modulates the associated vectors of symbols to obtain a second modulated signal on line 88. This second modulated signal is limited in a limiter 90, with the second threshold value K2.

Since the operation of the restriction creates intermodulation components, reduce them by using the operations described below. The second limited modulation signal on line 92 is sent to the demodulator in block 94. The demodulated output signal on line 96 is directed to a finishing operation in block 98, where the subcarriers are not transmitting data, one-sided limit to zero. The resulting signal on line 100 modulate in block 102, and the third modulated signal on line 104 limit in block 106 using another limiting threshold (K3). In the preferred implementation of this invention, the operations in blocks 94, 98, 102 and 106 repeat the 106 is not used but the signal is fed to the line 108 in high power amplifier for broadcast.

Amplifier high power in order modeling were used two models. Model 1 uses the limit function curve Z according to Fig.4. The limiter set at some threshold value K5. If the signal strength exceeds K5 (for normalized input signal), then at any moment of its one-sided limit to K5. Model 2 uses the limit function “S curve”. In this case, translated into the scale function 100 errors are used for modeling amplifier high power (see Fig.7). Operating point set by the value of K5. K5 value of 6 dB means that the mean value of the signal by 6 dB below the compression point 1 dB.

Fig.8 is a graph illustrating simulated results of power spectral densities OMCR-subcarriers in custom digital broadcasting sound signal with limit values K1=3; K2, K3, and K4=4; and the fraction F=7/8, using depicted in Fig.4 limiter, with different criteria final one-sided limits. The signal represented by line 112, is one-sided limit at 5.5+0,85 dB. Line 114 illustrates odnostoronie the results of one-way restrictions when 4,0+0,88 dB. Fig.9 illustrates the frequency of bit error for these variants, the number with a dash represent the corresponding results. Line 119 represents the results without unilateral constraints.

Fig.10 is a graph illustrating simulated results of power spectral densities OMCR-subcarriers in custom digital broadcasting sound signal by using the limiting values of K1=3; K2, K3, and K4=4; and part F=7/8, using depicted in Fig.4 limiter in the way of reducing OMMS and using depicted in Fig.7 limiter amplifier high power in the output signal of the transmitter. Signal without unilateral constraints depicted by line 120. Line 122 represents the unilateral limitation of 5.17+1,09 sigrms=-8. Fig.11 illustrates the frequency of bit error for these variants, numbers with a dash are given for relevant results.

Fig.12 is a schematic diagram that illustrates a method of reducing OMS according to this invention for all digital signal. Block 124 represents the following: the input vector of characters OMCR CSV data subcarrier injected into CSV-modulator 126, the first modulated signal modulirovannye signal on line 132, then demodulated in block 134 to restore the points of the constellation vector character data on line 136. Restored point constellation pre-distort in block 138, and thus bind to a predetermined minimum value of the in-phase and quadrature components according to the above. Unnecessary subcarriers that do not transmit data, also unilaterally restrict to zero in this operation. CSV-modulator 140 modulates the associated vectors of symbols to obtain a second modulated signal on line 142. This second modulated signal is limited in a limiter 144 with the second threshold value K2.

Since the restriction creates intermodulation components, reduce them in subsequent operations. The second limited modulation signal on line 146 is sent to the demodulator in block 148. The demodulated output signal 150 is passed to the block 152 in which the data symbols from the Central load-bearing pre-distort, and subcarriers are not transmitting data, one-sided limit to zero. Received on line 154 modulate the signal in block 156, and the third modulated signal on line 158 limit in block 160 with another limit threshold is 2, 156 and 160 is repeated twice, using a threshold value K4 is in the restrictor 160 at the first repetition. In the second iteration, the limiter 160 is not used, and routes the signal on the line 162 in high power amplifier for broadcast.

Fig.13 is a graph illustrating simulated results of power spectral densities OMCR-subcarriers in custom digital broadcasting sound signal using the limit value K1=3; K2, K3, and K4=4; and part F=7/8, using depicted in Fig.4 limiter, with different criteria final one-sided limits. Signal without unilateral constraints is illustrated by line 164. Line 166 represents a one-sided limit at 4.5+0,78 dB, line 168 depicts a unilateral constraint when 5,0+0,77 dB, and line 170 represents the results of one-sided limits at 5.5+0,77 dB. Fig.14 depicts the frequency of bit error for these variants, numbers with a dash indicate the corresponding results.

Fig.15 is a graph depicting the simulated results of power spectral densities OMCR-subcarriers in custom digital broadcasting sound signal using the limit value K1=3; K2, K3, and K4=4; and part F=7/8, poele amplifier high power in the output signal of the transmitter. The signal unilateral constraints is illustrated by line 172. Line 174 represents the unilateral constraint when sigrms=6, OMS=6,15+0,95 dB; and line 176 represents a unilateral constraint when sigrms=8, OMS=6,38+0,88 dB. Fig.16 depicts the frequency of bit error for these variants, numbers with a dash indicate the corresponding results.

All variants of the simulation performed using 512 OMCR characters. The optimal selected parameters were: K1=3 dB, K2=4 dB, K3=4 dB, C4=dB, F=7/8. Qualifying scores were: spectral power density (MTA) and the frequency of bit error (CPAB). Point the demodulated signal is depicted as a graph to illustrate the introduced distortion.

In the last step, the sample rate can be doubled by padding the signal with zeros in the frequency domain. To reduce the complexity of the method reduce OMS: the last operation can be done twice instead of three times. It would mean some loss of performance, but the SMP will still be within the hybrid template ITVC the world Cup.

This invention describes a non-novel method for reducing the ratio of maximum power to the average (OMS) in OMCR DLCI show this invention can provide a reduction OMS to 4-7 dB, while not beyond the template, FIFA world Cup. The distortion generated in accordance with this method of pre-distortion is minimal. In particular, using the parameters K1=3 dB, K2=4 dB, K3=4 dB, C4=4 dB, F=7/8 for CSV signal provides a very good graph spectral employment without leaving the confines of the template, FIFA world Cup. Moreover, the distortion introduced by this set of values is minimal.

This invention uses a combination of pre-distortion signal transmission with one-sided limit, to minimize OMMS the transmitted signal. Reduction OMS in the optimized signal transfer is demonstrated by simulation results. Although this invention is illustrated in preferred embodiments of its implementation, it is understood that in the disclosed method and system may be implemented in various modifications within the scope of the invention defined by the following claims, including equivalents. For example, this invention is illustrated from the point of view of its use for digital audio broadcasting, but it has more General application margin-top:2mm;">Claims

1. A method of reducing the ratio of maximum power to the average radio signal, namely, that modulate the set of subcarriers with a set of vectors of data symbols to obtain a first modulated signal, limit the magnitude of the first modulated signal to obtain a first limited modulated signal and demodulated first limited modulated signal to recover the vector of data symbols, wherein the pre-distort the recovered vectors of data symbols to provide a minimum value for the in-phase and quadrature components to obtain a pre-distorted vectors of character data, modulate the set of subcarriers using a pre-distorted vectors of data symbols to obtain a second modulated signal, limit the value of the second modulated signal to obtain a second limited modulated signal and reduce intermodulation components in the second limited modulation signal.

2. The method according to p. 1, characterized in that for reducing intermodulation components in the second vtorogo demodulated signal, one-sided limit to zero subcarriers is not transmitting data, the second demodulated signal and modulate the second demodulated signal to obtain a third modulated signal.

3. The method according to p. 2, characterized in that it further restrict third modulated signal.

4. The method according to p. 3, characterized in that it further demodulator third modulated signal to obtain a third demodulated signal, unilaterally restrict to zero subcarriers is not transmitting data, in the third demodulated signal and modulate the third demodulated signal to obtain a fourth modulated signal.

5. The method according to p. 4, characterized in that it further restrict fourth modulated signal.

6. The method according to p. 5, characterized in that it further demodulator fourth modulated signal to obtain a fourth demodulated signal, unilaterally restrict to zero subcarriers is not transmitting data, in the fourth demodulated signal and modulate the fourth demodulated signal to obtain a fifth modulated signal.

7. The method according to p. 1, characterized in that the vector of data symbols additional constellations are in-phase component and quadrature component, and when pre-distortion is additionally used to scale the in-phase component of each point of the constellation to a value that exceeds a first specified portion of the expected value of the inphase component or its equivalent, will scale the quadrature component of each point of the constellation to a value that exceeds the second specified portion of the expected magnitude of the quadrature component, or equal to it.

8. The method according to p. 1, wherein when the modulation of subcarriers together with the set of data symbols to obtain a first modulated signal are modulated using quadrature phase manipulation.

9. The method according to p. 8, wherein the subcarriers indicated totality of subcarriers are orthogonal multiplexed with the frequency separation of the carriers.

10. The method according to p. 1, characterized in that when the limit value of the first modulated signal to obtain a first limited modulated signal is additionally set a maximum value of the first modulated signal to a predetermined constant value.

11. The method according to p. 1, characterized in that when the limit value of the first modulated signal p of the first modulated signal by a specified amount, defined enumerated in the scale of the curve z

12. The method according to p. 1, characterized in that it further normalize these modulated subcarriers.

13. The method according to p. 1, wherein when the modulation of subcarriers together with the set of vectors of data symbols to obtain a first modulated signal further apply the inverse fast Fourier transform to the specified vector of data symbols, apply a cyclic prefix to the specified vector of data symbols and apply finite root of the weighing function to the extent of the cosine of the specified vector data characters.

14. A method of reducing the ratio of maximum power to the average radio signal, namely, that modulate the set of subcarriers with a set of vectors of data symbols to obtain a first modulated signal, with the first group of subcarriers is located in the upper and lower side bands of the radio channel, and the second group of subcarriers is located in the Central band of the radio channel, and limit the magnitude of the first modulated signal to obtain a first modulated signal, wherein remove intermodulation sostavlyala recovery points of the constellation data representing data characters, pre-distort the vector of data symbols in the first and second groups of subcarriers to ensure minimum value for the in-phase and quadrature components in order to generate a pre-distorted vectors of character data, modulate the set of subcarriers using a pre-distorted vectors of data symbols to obtain a second modulated signal, limit the value of the second modulated signal to obtain a second limited modulated signal, remove the intermodulation components in the second limited modulation signal and pre-distort the vector of data symbols in the second group of subcarriers to ensure minimum value for the in-phase and quadrature components in order to more pre-distorted vectors of data characters.

15. The method according to p. 14, characterized in that when you remove intermodulation components in the second limited modulation signal additionally demodulator second modulated signal to obtain a second demodulated signal, unilaterally restrict to zero subcarriers is not transmitting data, in Deuteronomy the signal.

16. The method according to p. 15, characterized in that it further restrict third modulated signal.

17. The method according to p. 16, characterized in that it further demodulator third modulated signal to obtain a third demodulated signal, unilaterally restrict to zero subcarriers is not transmitting data, in the third demodulated signal and modulate the third demodulated signal to obtain a fourth modulated signal.

18. The method according to p. 17, characterized in that it further restrict fourth modulated signal.

19. The method according to p. 18, characterized in that it further demodulator fourth modulated signal to obtain a fourth demodulated signal, unilaterally restrict to zero subcarriers is not transmitting data, in the fourth demodulated signal and modulate the fourth demodulated signal to obtain a fifth modulated signal.

20. The method according to p. 14, characterized in that the vectors characters advanced data include a set of constellation points representing data characters, the points of the constellation are in-phase component and quadrature component, and when predvaritel exceeds the first specified portion of the expected value of the inphase component or its equivalent, scale the quadrature component of each point of the constellation to a value that exceeds the second specified portion of the expected magnitude of the quadrature component, or equal to it.

21. The method according to p. 14, wherein when the modulation of subcarriers together with the set of data symbols to obtain a first modulated signal further perform modulation using quadrature phase manipulation.

22. The method according to p. 21, wherein the subcarriers indicated totality of subcarriers are orthogonal multiplexed with the frequency spacing of subcarriers.

23. The method according to p. 14, wherein when the limiting magnitude of the first modulated signal to obtain a first limited modulated signal is additionally set a maximum value of the first modulated signal to a predetermined constant value.

24. The method according to p. 14, wherein when the limiting magnitude of the modulated signal to obtain a first limited modulated signal is additionally set a maximum value of the first modulated signal to a predetermined magnitude determined recalculated scale crooked is.

26. The method according to p. 14, wherein when the modulation of subcarriers together with the set of vectors of data symbols to obtain a first modulated signal further apply the inverse fast Fourier transform to the specified vector of data symbols, apply a cyclic prefix to the specified vectors of data characters to the specified character data.

27. Radio frequency transmitter, providing reduced the ratio of maximum power to the average radio signal containing means (36) designed to modulate the subcarriers together with the set of vectors of data symbols to obtain a first modulated signal, means (40) designed to limit the magnitude of the first modulated signal to obtain a first limited modulated signal, and means (42) used for demodulation of the first limited modulated signal to recover the vector of data symbols, characterized in that it contains means (44), designed for pre-distortion of the reconstructed vectors of characters of data in order to ensure minimum value for the in-phase and quadrature - to modulation the aggregate carrying through pre-distorted vectors of data symbols to obtain a second modulated signal, means (48) designed to limit the magnitude of the second modulated signal to obtain a second limited modulated signal, means (50) designed to reduce intermodulation components in the second limited modulation signal.

28. Radio frequency transmitter, providing reduced the ratio of maximum power to the average radio signal containing means (36) designed to modulate the subcarriers together with the set of vectors of data characters, for receiving the first modulated signal, and the first group of subcarriers is located in the upper and lower side bands of the radio channel, and the second group of subcarriers is located in the Central band of the radio channel, and means (40) designed to limit the magnitude of the first modulated signal to obtain a first limited modulated signal, and to remove intermodulation components in the first limited modulated signal, characterized in that that contains a means (42) used for demodulation of the first limited modulated signal to recover the points of the constellation data representing singularly groups of subcarriers to ensure the least amount for their in-phase and quadrature components to obtain a pre-distorted vectors of data characters, means (46) designed to modulate the aggregate carrying through pre-distorted vectors of symbols of data to obtain a second modulated signal, means (48) designed to limit the magnitude of the second modulated signal to obtain a second limited modulated signal, means (50) that is designed to remove intermodulation components in the first limited modulated signal, and means (44) designed for pre-distortion vectors of the data symbols in the second group of subcarriers to ensure the least amount for their in-phase and quadrature components, for more pre-distorted vectors of data characters.

 

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6 cl, 22 dwg

FIELD: communication engineering, possible use for engineering and production of synchronous and asynchronous communication systems as system for transferring discontinuous information, in communication channels with unstable parameters and leaping frequency readjustment under effect from intentional pulse interference.

SUBSTANCE: system consists of transmitter portion, which has clock pulse generator, Different-code generator, generator of double frequency manipulation signals, modulator, frequencies synthesizer, pseudo-random numbers generator, connected via broadcast pipe to receipt portion, which has demodulator, frequencies synthesizer, pseudo-random numbers generator, signals selector, clock pulse generator, block for selecting additional series, first and second two-channeled synchronized filters, first and second subtracter, interference compensator and resolving block.

EFFECT: higher resistance to interference and trustworthiness under effect from intentional pulse interference in communication channels with random parameters of signal for systems with code compression of signals and systems with multiple access.

2 cl, 8 dwg

FIELD: radio engineering, possible use in fiber-optic communication systems.

SUBSTANCE: device has commutator, k-1 delay blocks, branch device, multi-branch delay line, k-1 transformers of pulse series, law-setting block, block for processing optical signal and solving block.

EFFECT: increased resistance to interference or increased length of regeneration portion of fiber-optic communication line.

3 cl, 6 dwg

FIELD: engineering of devices for generating series of preamble with low ratio of pike to average power in communications system with orthogonal multiplexing and frequency separation of channels.

SUBSTANCE: in accordance to method, first series of preamble is generated, wherein odd data of input series of preamble are transformed to zero data, and even data of aforementioned series are transformed to nonzero data, first series of preamble is transmitted through one of two antennas, second preamble series is generated, wherein even data of input series of preamble are transformed to zero data, and odd data of aforementioned series are transformed to nonzero data, second series of preamble is transmitted through another antenna.

EFFECT: increased efficiency.

6 cl, 10 dwg

FIELD: radio engineering.

SUBSTANCE: device implementing proposed method designed for use in pseudorandom operating frequency tuning radio communication systems and in monitoring systems of the latter has first and second band filers 1 and 3, respectively, first and second multipliers 2 and 16, respectively, demodulator 4, first, second, third, and fourth delay lines 4, 5, 7, and 9, respectively, adjustable frequency synthesizer 6, first, second, third, and fourth spectrum analyzers 10, 11, 12, and 13, respectively, first and second subtracters 14 and 15, respectively, comparator 17, and maximal higher-than-threshold component searching unit 18.

EFFECT: ability of signal reception and demodulation in case of a priori uncertain pseudorandom operating frequency tuning program.

2 cl, 8 dwg

FIELD: technology for exchanging digital data with usage of transfer system based on multiplexing with orthogonal frequency division of channels, including at least one transmitter, and receivers.

SUBSTANCE: method includes selection of operation mode in transmitter from at least one mode, while each operation mode is associated with a number of active carriers for transferring useful data, selection of interlacing symbol in aforementioned selected operation mode, usage of symbol interlacing in transmitter in relation with data element blocks, display of interlaced elements of data on active carriers of aforementioned selected operation mode, receipt of interlaced data elements in receiver, recognition in receiver of symbol interlacing symbol used during data transfer, selection of reversed interlacing symbol in receiver for match with recognized interlacing symbol and reverse interlacing in receiver of received data elements by means of selected reverse interlacing symbol.

EFFECT: increased stability of system due to efficient correction of errors.

4 cl, 9 dwg

FIELD: technology for processing digital signals.

SUBSTANCE: in digital multi-frequency transmitter-receiver during receipt signals are simultaneously decimated and roughly converted with frequency decrease in iteration process for narrowing received broad range of frequency down to required channel, and during transmission signals are interpolated iteratively for receiving required frequency of digitization and width of frequency band.

EFFECT: provision of processing of digital signal at digitization frequency of analog-digital converter.

6 cl, 21 dwg

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