SU932629A1 - Telegraphy signal receiving device - Google Patents

Description

(54) TO GET TELEGRAPH SIGNALS

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The invention relates to radio technology and can be used in a device for receiving discrete signals.

A device for receiving telegraphic signals is known, which contains spatially separated antennas that are connected via radio receiving units to the first inputs of corresponding signal splitters, the outputs of which are connected to the inputs of the computing unit and to the first inputs of the corresponding multipliers, the outputs of which are connected to the inputs of the adder, the output of which is connected through the first terminator to the input of the detector information signal, while the second inputs of the splitters are connected to the input of the phase shifter, the output of which It is connected to the third inputs of the signal splitters, as well as the first additional multiplier, the measuring filter, the second limiter, the second additional multiplier and the subtractive unit, the output of which is connected to the corresponding input of the computing unit, the outputs of which are connected to

the second inputs of the respective multipliers 1.

However, the known device has a low noise immunity for receiving narrowband telegraph signals.

The purpose of the invention is to improve the noise immunity of receiving narrowband telegraph signals.

The goal is achieved by the fact that

10 a device for receiving telegraphic signals; a delay element and a low-pass filter connected in series; a regenerator of information symbols and a signal conditioner whose outputs are connected;

ts to the second input of the second additional multiplier and to the first input of the first additional multiplier, the second input of which is connected to the second input of the reading unit and the output of the delay element, the input of which is connected to the output of the adder, and the output of the information signal detector is connected to the input of the low-pass filter. The drawing shows a structural electrical circuit of the proposed device. Telegraph Receiver || The signal contains radio receiving blocks 1, signal splitters 2, each of which consists of mixers 3 n filters 4 lower frequencies, phase shifter 5, multiplier c 6, adder 7, first limiter 8, information signal detector 9, low-pass filter 10, regenerator 11 information symbols, a signal conditioner 12, a delay element 13, a first additional alternator 14, a measuring filter 15, a second limiter 16, a second additional multiplier 17, a subtraction unit 18, a computing unit 19, spaced s antenna 20. The device operates as follows. . The device contains N spatially separated antennas, radio receiving unit 1 is connected to each of the KOTOI IX. Accepted. The signal and interference mixture at the intermediate frequency comes to the splitter, which consists of mixers 3 and low-pass filters 4. The other input of each of the mixers 3 is supplied from outside by a suppressed voltage with a frequency equal to the intermediate frequency. Mixer color is connected in parallel in each branch of the mixer 3, and the reference voltage is fed to the inputs of these mixers with a phase shift of 90 °, which ensures the decomposition of the narrowband signal and interference mixture into quadrature components. The doubled intermediate frequency arising in the mixer is filtered out by a low-pass filter at which the real and imaginary components of the signal are extracted. The multiplier x 6 multiplies the complex ve; the causes of S (t), the corresponding signal mixture and interference for the complex weighting factor W (t) coming from the computing unit, i.e. at the output of the i-ro multiplier, we have a complex value) S, (i). The signals from the output of all i-x multipliers 6 are summed in adder 7, the output of which yields fl: (- t). 1 Output Process from the adder 7 SjCt) is fed through the first limiter 8, the detector 9 of the information signal, low-pass 10, the regenerator 11 to the control input of the signalformer 12 of the signal as an estimate of the telegraph parcels b (t). This shaper 12 generates a fluctuation AT, TH or SCRT in accordance with the type of received information. This oscillation has the form) - - TH signal (1)) for the OFT signal (2) Ct) l (.- fc) for the AT signal (2, where bk (1) is the telegraph packet estimate recoded for the OFT; b (t ) - evaluation of telegraph packages; 9- - frequency deviation;% - initial phase. The oscillation generated in this way goes to the input of the second additional multiplier 17. To the input of the first additional multiplier 14 comes from the former 12 complex-conjugate oscillation) "-ChO-THY signal (3) Q -} (} - Kll for the OFT signal (4) (-b) b (-t) for the AT signal. (4). On the other hand, to the input of the first extension of the multiplier 14 through the delay element 13, which compensates for the evaluation delay of the demodulated information signal b (t) relative to the envelope of the manipulated signal from the output of the adder 7, the oscillation comes from the output of the adder 7 S (t), which can be represented as rb (t) SL6S (t) -s. (-t) .s sip “,) yes THU signal (5) yt; -seffl Ve - for the OFT signal (6), where Sc is the module of the signal envelope; f (t) is the slow fluctuating phase of the signal caused by channel effects; Sip is the i-th interference envelope module; O) fzza interference. At the first additional multiplier 14, the production n, (t) is calculated. For the THU signal, the expression for Pz (t) needs to be substituted (5). As a result, we get n, (t) e. (T) «. -HS ipWe In the case when the ratio of the siga-interference is large enough, we get b (O-b) g. -. (. Cm) 4 (i:) ai3 ni (t) s e. 2 Sip (t) e (8) The second term in (8), which is a product of interference conversion with a much wider spectrum, does not pass through the measuring filter 15, i.e. at the output of the measuring filter 15 moidao write cM), (9) where Kf is the transmission coefficient of the measuring filter at zero frequency. After the second limiter 16, which leads the modulus of oscillation (9) to unity and the subsequent multiplication in the second additional multiplier of 17 expressions (9) by (1), we get H-FadMsi-e H -. (OSli + f (t) J as a result of (10) is a reference signal; d, which is an estimate of the transmitted information, which is reduced as a decrement to the computing unit. Signal (5), delayed by so many that b (t) and b (t) coincide in time. Then, at the output of subtractive unit 18, we have e (t). (t) a-t4 (t) 3 See i4 (t) Automatic control system using weights W that are generated in the computing unit 19, are normalized by Sc to 1, with the result that eC-t) - e-ipe is a pure interference, which Its automatic control system minimizes. Thus, the use of the proposed device makes it possible to compensate for up to N-I interference with the reception of narrowband telegraph signals and thereby increase the noise tolerance of the reception of telegraph sitnals. Apparatus of the Invention A device for receiving telegraphic signals comprising spatially separated antennas that are connected via radio receiving units to the first inputs of respective signal splitters, the outputs of which are connected to the inputs of the computing unit and to the first inputs of the corresponding multipliers, the outputs of which are connected to the inputs of the adder, the output of which is through the first the limiter is connected to the input of the information signal detector; in this case, the second inputs of the signal splitters are connected to the input of the phase rotation the body, the output of which is connected to the third inputs of the signal splitters, as well as the first additional multiplier, the measuring filter, the second limiter, the second additional multiplier and the subtractive unit, the output of which is connected to the corresponding input of the computing unit, whose outputs are connected to the second inputs of the corresponding multipliers, characterized in that, in order to improve the noise immunity of receiving narrowband telegraph signals, a delay element has been introduced into it, and Consistently connected low-pass filter, information symbol regenerator and shaper sigal, the outputs of which are connected to the second input of the second additional multiplier and to the first input of the first additional multiplier, the second input of which is connected to the second input of the subtracting unit and to the output of the delay element whose input is connected to the output adder, and the output of the detector information signal connected to the input of the filter of the lower frequencies. Sources of information taken into account in the examination 1. Compton R. G. Adaptive antenna array in a broadband communication system. - TII ER, t. 66, No. 3. 1978, p. 23-24 (about, totype).

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Claims (1)

Claim A device for receiving telegraph signals containing spatially spaced antennas that are connected via radio receiving units to the first inputs of the corresponding signal splitters, the outputs of which are connected to the inputs of the computing unit and to the first inputs of the corresponding multipliers, the outputs of which are connected to the inputs of the adder, the output of which is connected through the first limiter to the input of the detector of the information signal, while the second inputs of the signal splitters are connected to the input of the phase shifter, the output of which is splitters for prison to the third input signal and connected in series (ίο) As a result, (10) is a reference signal, which is an estimate of the transmitted information, which comes as ’’ reducible ”to the computing unit. 3 ° A signal ^ (5) is received as a ’’ subtracted signal, delayed so much that b (t) and b (t) coincide in time. Then at the output of the subtracting block 18 we have with „„ An automatic control system with ₄₀ weights W4, which are generated in the computing unit 19, normalize S _c to 1, as a result of which € (£) · is a “pure” interference, which is minimized by the same automatic control system. Thus, the application of the proposed device allows you to compensate up to N-1 ^{50 the} first additional multiplier, a measuring filter, a second limiter, a second additional multiplier and a subtracting unit, the output of which is connected to the corresponding input of the computing unit, the outputs of which are connected to the second inputs of the respective multipliers, characterized in that, in order to increase the noise immunity of receiving narrow-band telegraph signals, a delay element and series-connected phi are introduced into it low-frequency litter, information symbol regenerator and signal generator, the outputs of which are connected to the second input of the second additional multiplier and to the first input of the first additional multiplier, the second input of which is connected to the second input of the subtracting unit and to the output of the delay element, to the input of which the output of the adder is connected, moreover, the output of the information signal detector is connected to the input of the low-pass filter.