SU769747A2 - Device for two-channel reception with discrete autoselection - Google Patents

Description

one

The invention relates to the field of radio receivers, can be applied in the implementation of two-channel reception.

According to the main author. St. No. 2,72388, a device for dual-channel reception with discrete auto-selection known in the field of radio receivers, contains two channel demodulators, two signal-to-noise ratio meters, two channel keys, a differential device, and adder 1.

However, the device works well only when the signal-to-noise ratio in one channel is significantly higher than the other. If this is not observed, then there are times when the signal-to-noise ratio meters produce the same results. In these cases, the output of the difference device control is lush, its signal is not present, the channel keys either remain not turned on, or are turned on simultaneously. Even with a good signal-to-noise ratio in both channels, this leads either to a complete loss of the received information or to cross-distortions in the adder, which significantly reduces the interference immunity of the reception as a whole.

The aim of the invention is to improve noise immunity.

For this, in the device for two-channel reception with discrete auto-selection, containing demodulators, and signal-to-noise ratio, differential device, channel keys and adder, the outputs of the control unit are connected to the channel key inputs, the first input of which is connected through the state analyzer of the differential device the output of the differential device, and the second input through the comparison element - with the outputs of the channel switches.

Claims (1)

The drawing shows an electrical structural diagram of the device for 115 two-channel reception with discrete auto selection. The device consists of demodulators 1 and 2, whose inputs are respectively connected to the inputs of the signal-to-noise ratio meters 3 and 4. The outputs of demodulators 1 and 2, respectively, are loaded on the first the inputs of the channel switches 5 and 6, the second inputs of which are connected to the output of the differential device 7, the two inputs of which are respectively connected to the outputs of the signal-to-noise ratio meters 3 and 4. The outputs of the switches are loaded to the inputs Odmator 8 and the inputs of the comparison element 9. The output of the differential device 7 is connected to this input of the state analyzer of the differential device 10, the output of which is connected to the first input of the control unit 11. The second input of the control unit I is connected to the output of the comparison element 9, and the outputs to the third the inputs of the channel keys 5 and 6, respectively. The inputs of the device are supplied with voltage and "x | and and XV, which are a mixture of the signal i of the noise of the corresponding channels. These voltages are simultaneously received at demodulators 1 and 2 by the sigual / common meters 3 and 4 meters. Depending on the type of modulation used, demodulators 1 and 2 are amplitude, frequency, or phase detectors. At the output of the demodulators, video signals Ui and U2 are formed. The received video signals are fed to channel keys 5 and 6 with different polarity after launch. When the control voltage is applied and output from the differential device 7 to the keys 5 and 6, a discrete automatic video signal is output at the output of the adder 8 depending on the signal-to-noise ratio of one channel in comparison with another - the signal from the output of the adder 8 is output to the device. If both channels are affected by proportional noise simultaneously, uncertainty arises in the choice of channel and the signal controlled by keys 5 and 6 does not appear at the output of difference device 7. The state analyzer of the differential device 10 determines the presence of a signal controlling the operation of the channel switches 5 or 6, sends a resolution signal to the control unit 11 in the absence of a control signal. When a control signal appears at the output of the difference device 7, the resolution signal is removed and the control unit 11 is turned off. The control unit AND, in the presence of a resolution signal at the output of the state analyzer of the differential device 10, makes it possible to leave one of the channels on which information was received before the appearance of the resolution signal. In the case of the occurrence of the enable signal when the receiving device is turned on, the control unit 11 includes any of the channel keys 5 and 6, allowing to begin receiving information on one of the channels. Comparison element 9 determines the presence of a received signal in a particular channel and sends to the control unit 11 a signal on the operation of the corresponding channel. Thus, the elimination of reception uncertainty is carried out in the presence of a mixture of signals with commensurate noise at the channel inputs. Claims of the Invention A device for two-channel reception with a discrete auto-selection on aut. No. 272388, characterized in that, in order to increase noise immunity, the outputs of the channel keys are connected to the outputs of the control unit, the first input of which is connected to the output of the differential device through the state analyzer of the differential device, and the second input is connected to the outputs of the channel keys Sources information taken into account during the examination 1. USSR author's certificate L. 272388, cl. H 03 D 3/18, 1968. f-%, I