The way information transmission and converter sequence of digital samples

 

The invention relates to techniques for transmitting and receiving information. The technical result is to reduce the amount of distortion in the transmission of discrete digital samples of information. How is that on the transmission side converts a sequence of digital samples to an analog signal using samples type sinx(cos(x/n)-1)/2nsin(x/n), where x= 2FinFinthe upper frequency in the spectrum of the transmitted analog signal, a n is an integer equal to the number of used frequency components in the spectrum of the analog signal. The resulting analog signal is passed to a communication line. At the receiving side, the original sequence of digital samples to recover using this function counts. The data transmission method is implemented using the appropriate Converter sequence of digital samples to an analog signal. 2 C. p. F.-ly, 3 ill.

Technical field the Invention relates to techniques for transmitting and receiving information and can be used in communication systems, measurements, etc.,

The existing level of technology In the transmission of discrete information on Cana is the country in such channels of communication sequence of discrete digital samples of information is converted into an analog signal using a given function counts, introduces distortions in the transmitted analog signal.

Well-known given function countswhere x=2FinFinthe upper frequency in the spectrum of the transmitted analog signal has a rectangular range on the innite time interval. Actually transmitted analog signals take a finite time interval, so that the result of converting digital samples of information: the result of multiplying the specified function countsthe sequence of digital samples of information, previously converted into rectangular (ideally) signals, leads to a significant expansion of an ideal rectangular spectrum. When the final filtering at the receiving side of the analog signal with the same range, i.e., when cutting off the "tails" of the spectrum of the transmitted analog signal, inevitably distorted (Gonorovski I. S. Radio circuits and signals. - M.: Owls. radio, 1977, S. 55-58).

Well-known attempt to remedy this situation by finding the optimum of a given function counts to ensure minimal distortion of the analog signal at the reception (Kotelnikov Century A. "Pulses with Naumenko in this work such a function was not found.

There is a method of transmitting information, namely, that on the transmission side converts a sequence of digital samples to an analog signal using a specified function counts and transmit the generated analog signal to a communication line, and at the receiving side take the specified analog signal from the communication line and using the specified function counts recover from a received analog signal to a sequence of digital samples of information (tiled Japan's bid 10-098497, H 04 L 27/10, 14.04.1998). Using this method of information transfer known given function referencein some cases leads to the intake after the filter to the distortion of the sequence of digital samples of information that ultimately can lead to the loss of transmitted information.

The objective of the invention and the technical result of the invention is to develop a method of transmitting data in which the specified function counts for converting the sequence of digital samples to an analog signal reduces distortion, as well as the development of the Converter sequence of digital samples in the anal which is less distortion of the sequence of digital samples of information when filtering the recovered analog signals at the receiving side.

The invention is a method of information transmission according to the invention is that on the transmission side converts a sequence of digital samples to an analog signal using a specified function counts and transmit the generated analog signal to a communication line on the receiving side take the specified analog signal from the communication line and using the specified function counts recover from an analog signal to a sequence of digital samples of information, and as specified function counts usewhere x=2Fin,
Finthe upper frequency in the spectrum of the transmitted analog signal,
n is an integer greater than one, equal to the number of used frequency components in the spectrum of the analog signal.

To solve the problem and achieve the same technical result according to the present invention is proposed Converter the sequence of digital samples using the specified function counts

where x=2Fin,
Finthe upper frequency in the spectrum of the transmitted analog signage signal, containing eight series-connected individual units conversion (1), each of which consists of the first (2) and second (3) multiplier products, adder (5) and quadrature phase shifter (4), the quadrature phase shifter (4) combined with the information input of the first multiplier (2) and an information input of this block conversion, and the output of the quadrature phase shifter (4) connected to the information input of the second multiplier (3), and the outputs of each of the specified multiplier connected to the respective first and second inputs of the adder (5), the output of which is a separate output of the conversion unit, with the reference inputs of the first multiplier products (2.1, 2.2) and the reference inputs of the second multiplier products (3.1, 3.2) of the first and second conversion blocks, respectively, are combined and are used as inputs quadrature reference oscillations to twice the sampling frequency, the reference inputs of the first multiplier products (2.3, 2.4) and the reference inputs of the second multiplier products (3.3, 3.4) the third and fourth conversion blocks, respectively, are combined and are used as inputs quadrature reference frequency of sampling, the reference inputs of the first multiplier products (2.5-2.8) and the reference inputs of the second hadreturned reference oscillations at half the sampling frequency, the information input of the first conversion unit is an information input of the Converter sequence of digital samples of information, and the output of the eighth conversion unit is an inverter output sequence of digital samples of information.

Brief description of drawings
The present invention is illustrated with the description of the embodiments thereof with reference to accompanying drawings.

Fig.1. A view of the specified functiontimes,
where x=2Fin,
Finthe upper frequency in the spectrum of the transmitted signal,
n=16.

Fig.2. Range specified function of the samples in Fig.1.

Fig.3. The block diagram of the Converter of the sequence of digital samples using a given function of the samples shown in Fig.1.

Detailed description of the invention
To achieve the minimum distortion for receiving a sequence of digital samples of information after filtering the specified function counts must be periodic with a period that is bound to the repetition period of the sequence of digital samples Twith=1/Fina range specified function counts should be compact with level side �a/61/615043.gif">
where x=2Fin,
Finthe upper frequency in the spectrum of the transmitted analog signal,
n is an integer greater than one, equal to the number of used frequency components in the spectrum of the analog signal has the form shown in Fig.1 (shown for n=16). The value of n is determined by the formula n=T/2Twithwhere T is the given processing interval (period specified function counts), in this case 10,66667 MS, and Twith=1/Finthe repetition period of the sequence of digital samples of information. This is a given function of the samples has a double periodic character: component sin provides "high-frequency" frequency, which is attenuated as the distance from the Central value. However, this attenuation goes on to infinity, because the componentspecifies the lower-frequency frequency (with a period of n times). Due to this range of the specified function of the samples of the form (1), shown in Fig.2, differs from the spectrum of the known preset function countsthe fact that he has not rectangular, and descending form. Because of this, the range of end-time analog signal received by a given function of samples of the form (1), is finite and almost not distorted when filtering at the receiving side.

Converting the sequence of digital samples to an analog signal using a given function of samples of the form (1) can be implemented in both software and hardware. Implementation of conversion using software similar to the construction of the digital filter with impulse response.

The block diagram of the hardware implementation of the Converter of the sequence of digital samples of information rectangular shape to an analog signal using a given function of samples of the form (1) shown in Fig.3. This diagram Converter digital samples consists of eight identical blocks of transform (1.1-1.8), connected in series. Each conversion unit includes first (2.1-2.8) and second (3.1-3.8) multiplier products, quadrature phase shifter (4.1-4.8) and the adder (5.1-5.8). In Fig.3, each processing block is denoted by the reference position 1.i, where i indicates the sequence number of this block 1 conversion. Each element of the corresponding block 1 conversion also has a dual designation, where the second digit specifies the number conversion unit, in which the ion input of the second multiplier 3, and the outputs of each of the specified multiplier 2 and 3 are connected to the respective first and second inputs of the adder 5. When this input quadrature phase shifter 4 is combined with the information input of the first multiplier 2, and an information input of the Converter sequence of digital samples, and the output of the adder 5 is the output sequence of digital samples.

The reference inputs of the first multiplier products 2.1 and 2.2 and the reference inputs of the second multiplier products 3.1 and 3.2 of the first and second blocks 1.1 and 1.2 conversion, respectively, are combined and are used as inputs 6 and 7 of the quadrature reference oscillations to twice the sampling frequency of the entire Converter digital samples, i.e., the frequency corresponding to the value 4 in the expression (1). The reference inputs of the first multiplier products 2.3 and 2.4 and the reference inputs of the second multiplier products 3.3 and 3.4 of the third and fourth blocks 1.3 and 1.4 conversion, respectively, are combined and are used as inputs 8 and 9 of the quadrature reference frequency of sampling of the entire Converter sequence of digital samples, i.e., the frequency corresponding to the value of 2 in the expression (1). Finally, the reference inputs of the first multiplier products 2.5, 2.6, 2.7 and 2.8 and the reference inputs of the second peresa inputs 10 and 11 of the quadrature reference oscillations at half the sampling frequency, i.e., the frequency corresponding to the value of x in the expression (1). The information input of the first unit 1.1 conversion is an information input 12 of the Converter sequence of digital samples, and the output of the eighth block 1.8 conversion is output 13 of the Converter sequence of digital samples.

Quadrature phase shifter 4 in each block 1 conversion provides the phase change arriving at its input signal by the value of/2 (for frequencies Fin).

Before entering on the input of the Converter sequence of digital samples of the original sequence of discrete digital samples transform using a digital to analogue Converter (DAC) in a sequence of rectangular pulses with amplitude equal to the amplitude of corresponding digital samples of information.

Quadrature reference oscillation serves to corresponding inputs of the Converter sequence of digital samples from an external pulse generator, the outputs of which form the quadrature reference oscillations of double, single and half the sampling frequency.

Coming to the information input of the Converter 12 posledovatelnostei of which quadrature phase shifter 4 changes the phase of the digital readout on/2. Next, rectangular (quadrature) components of the specified sequence of digital samples to arrive at the appropriate multiplier products 2 and 3, where they perform their multiplication with the quadrature reference oscillations supplied from the pulse generator. The result of the multiplication is summed up by the adder 5 and serves on the output unit 1.1 conversion. In the following blocks 1.2-1.8 conversion sequentially processing the signal from the previous block 1 conversion. In the first two blocks 1.1 and 1.2 conversion quadrature components of the input signal are multiplied with fluctuations twice the sampling frequency, i.e., a quadruple frequency Fin(the upper frequencies in the spectrum of the transmitted analog signal), the following two blocks 1.3 and 1.4 converting the multiplication is performed with the frequency of sampling, i.e., twice the frequency Fin. In the last four sections of 1.5-1.8 multiplication component of the input signal is carried out with fluctuations half the sampling frequency, or frequency Fin. The output of the eighth unit Converter 1.8 sequence of digital samples is formed an analog signal representing the product of the input posledovatel is
where x=2Fin,
Finthe upper frequency in the spectrum of the transmitted analog signal,
n is the number of frequency components in the spectrum of the analog signal(in this example n=16).

At the receiving side from a received analog signal to restore the original sequence of digital samples of information using a digital filter with impulse response equal to the specified function reference on the transmission side.

Restored by the present invention at the receiving side a sequence of digital samples of information has distortion in the reference points (in the absence of noise) is not worse than 10-4%, compared with the known method on the prototype, in which the corresponding distortion is 1%.

Industrial applicability
This invention can be used in communications technology, dimensions, and any other applications where it is necessary to transfer or convert the information using the specified function of the timing information. This prompted the specified function counts ensures minimum distortion in the transmission of discrete samples in real communication channels with carrier frequency.

If the input of Palotai Fin(the upper frequency in the spectrum of the transmitted analog signal), then the Converter will function generator proposed specified function counts

and can be used in the specified quality in the technique of sending and receiving information.

Although the present invention is described with reference to a specific example of implementation, this example in no way limits the scope of patent claims, which is defined by the attached claims with regard to the possible equivalents.


Claims

1. The method of transmission of information, namely, that on the transmission side converts a sequence of digital samples to an analog signal using a given function of timing, transmit the generated analog signal to a communication line on the receiving side take the specified analog signal from the communication line, using the specified function counts recover from an analog signal to a sequence of digital samples of information, characterized in that as a given function of the samples use the function

where x=2 n is an integer greater than one, equal to the number of used frequency components in the spectrum of the analog signal.

2. The Converter sequence of digital samples, containing eight series-connected individual units conversion (1), each of which consists of the first (2) and second (3) multiplier products, adder (5) and quadrature phase shifter (4), the quadrature phase shifter (4) combined with the information input of the first multiplier (2) and an information input of this block conversion, and the output of the quadrature phase shifter (4) connected to the information input of the second multiplier (3), thus the output of each of the specified multiplier connected to the respective first and second inputs of the adder (5), the output of which is a separate output of the conversion unit, with the reference inputs of the first multiplier products (2.1, 2.2) and the reference inputs of the second multiplier products (3.1, 3.2) of the first and second conversion blocks, respectively, are combined and are used as inputs quadrature reference oscillations to twice the sampling frequency, the reference inputs of the first multiplier products (2.3, 2.4) and the reference inputs of the second multiplier products (3.3, 3.4) the third and fourth blocks preobrazovaniya inputs of the first multiplier products (2.5-2.8) and the reference inputs of the second multiplier products (3.5-3.8) fifth eighth conversion blocks, respectively, are combined and are used as inputs quadrature reference oscillations at half the sampling frequency, the information input of the first conversion unit is an information input of the Converter digital samples, and the output of the eighth conversion unit is an inverter output sequence of digital samples.

 

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