RU2591007C1 - Method of encoding information and device for implementation thereof - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: invention relates to radio engineering and specifically to wireless digital communication, and can be used for encoding information in digital cellular, personal and mobile systems. Method is based on modulation of input information signal and comprises steps of digitising and scrambling signal, processing obtained data as follows: encoding obtained unit of information signal of upper half-wave sinusoidal carrier, and a logic zero - lower half-wave, wherein number of zeros and number of units in output sequence is almost equal to each other, and their distribution on sequence is equiprobable.

EFFECT: technical result consists in narrow spectral width of signals of transmitted information, high transmission speed.

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Description

The invention relates to radio engineering, namely to wireless digital communications and can be used in the field of digital cellular, personal and mobile systems.

A common problem with these systems is to reduce the width of the spectrum of the signals, and consequently, increase the transmission speed.

Well-known types of modulation of information signals: amplitude, frequency, phase, etc.

The closest analogue is the modulation method, in which the transmission speed increases significantly, see the book by K. Feer, "Wireless Digital Communication". M .: Radio and Communication, 2000, p. 470 and 478? fig. 11.3.4. In this system, smoothing of the transmitted pulsed signals is proposed (“overwhelming” their tops).

Disadvantage: this is a half solution, because the log. 1 is encoded by the pulses themselves, and the log. 0 distance between pulses, which will not give the desired speed, tk. the spectral density of the transmitted signals remains wide enough.

An object of the invention is the narrowing of the width of the spectrum of the signals of the transmitted information, and therefore? increase in transmission rate, i.e. improving the quality of coding.

The technical result is achieved by using a new type of modulation: sinusoidal, in which the logical unit of the information signal is encoded by a positive half-wave sinusoidal carrier, and a logical zero by the lower half-wave.

Such a coding system to date does not exist.

To solve this problem, we propose a method of encoding information based on the modulation of the input information signal, which the signal is digitized, scrambled, and processed the received information sequence as follows: encode the received unit of the information signal of the upper half-wave sinusoidal carrier, and the logical zero - the lower half-wave, and the number of zeros and the number of units in the output sequence are almost equal to each other, and their distribution by sequence with equal probability; the device comprises an input information bus, a control device, a scrambler, DAC, low-pass filter and a power amplifier loaded on the radio channel antenna with the following connections: the input information signal bus is connected to the first input of the control device, the output of the scrambler is connected to its second input The outputs of the control device are from the input of the DAC, whose output is through the low-pass filter and a power amplifier connected to the antenna of the radio channel.

In FIG. 1 is an electrical block diagram of a device; FIG. 2 is a view of a sinusoidal synthesized carrier, and FIG. 3 - spectrum of one period of this carrier.

In FIG. 1, the following designations are adopted: 1 - control device (UE), 2 - scrambler, 3 - DAC, 4 - low-pass filter, 5 - power amplifier (UM), 6 - power source, A - antenna, RC - radio channel. FIG. 1 has the following connections: the information signal bus (inf. Signal) is connected to input 1 of UU1, the output of scrambler 2 is connected to input 2 of UU1, the output of which is connected to the inputs of DAC 3, and its output through the low-pass filter 4 and amplifier 5 is connected to antenna A system. The connection of the power source 6 is not conventionally shown.

The nodes of FIG. 1 can be performed on the following ERE and IC.

- УУ1 can be performed on a high-speed microprocessor, for example, from the NXP company of the LPC13XX family. see http://www.nxp.ru;

- Scrambler 2 - on a FPGA FPM240T100C5 chip from Altera, see http://www.altera.com/literature/lit-max2.jsp;

- DAC 3 on the MAXIM microcircuit MAXIM see http://gaw.ru/html.cgi/txt/ic/Maxim/dac/16bit/MAX5891.htm;

- UM 5 (power amplifier) on a linear amplifier of the MGA-53453 type, see http: //www/avagotech.com;

- LPF 4, for example, based on the book of the author A.S. Kotousov et al. "Optimal filtering of signals and interference compensation." M .: "Hot line", Telecom, 2008, p. 28-41;

The device operates as follows.

As is known from the Kotelnikov theorem for representing an analog signal using digital samples, it is necessary to use a sampling frequency of at least twice the upper frequency of the analog signal to be digitally processed. In real technical systems, to improve the shape of an analog signal, the sampling frequency must exceed its upper frequency by 3 ... 10 times. The operating frequency of modern microprocessor systems is constantly growing, currently reaching 3 ... 4 GHz in ordinary personal computers. Taking into account these figures, it is possible to form a carrier sinusoidal signal directly in a digital way by controlling a digital-to-analog converter using a high-speed microprocessor.

The input information signal is digitized in the ADC of the microprocessor 1, the synchronization of which is carried out by a clock frequency ft, which is obtained by adding a random sequence to the input information signal in the scrambler 2. Then, each bit of the digitized signal is sequentially processed: its logical level is determined log. 0 or log. 1, which is used in the DAC 3 to obtain the half-wave sign of the sinusoidal signal. The sinusoidal signal itself is programmed in MP1 and, in the form of a parallel code, is fed to the information inputs of DAC 3, the output of which is a sinusoidal signal if two adjacent bits of digitized information are a log. 0 and the log. 1 (or per revolution). If two neighboring bits are represented as "log. 1", then the output of the DAC. 3 we have two positive half-waves, if two “log. 0”, then two negative, etc. The frequency of the signals at the output of the DAC 3 is determined by the clock frequency ft in the same way as the operation of MP1.

The half-wave sign at the output of the DAC 3 is determined either by a single bit at its information input (the most significant digit) or by switching the voltage sign at its reference input. Each half-wave obtained at the output of the DAC 3 is smoothed out by the filter 4 and, through the power amplifier 5, loaded onto the antenna A, is radiated by the radio channel of the Republic of Kazakhstan.

The proposed design of the circuit allows you to get a new encoding of the information signal, which increases the reliability of synchronization and reduces the level of interference emitted to adjacent data lines, also protects the transmitted information from unauthorized access.

Claims (1)

A method of encoding information based on the modulation of the input information signal, characterized in that the input information signal is digitized, scrambled, processed, the received information sequence as follows: encode the received unit of the information signal of the upper half-wave sinusoidal carrier, and the logical zero - lower half-wave, and the number of zeros and the number of units in the output sequence are almost equal to each other, and their distribution over the sequence is equal okay.

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