The short-wave broadband communication device for transmission the analog narrowband signals

The transmission of information via the radio channel always involves the selection of radio waves modulation and the frequency band occupied by the radio signal. For the narrowband analog signals, the transmission via the radio channels in areas with difficult terrain the short-wave range is widely used. The majority of radio stations use frequency modulation of the transmitter without any message encryption. This gives the opportunity to detect and intercept messages that are transmitted. The use of the voice scramblers allows to hide information that is transmitted via the communication channel, but it is impossible to hide the radiation of the transmitter. The article suggests the use of a broadband signal with a modulation which is not associated with the change of the frequency of the transmitter in accordance with information, which is transmitted. The calculations showed that the proposed communication system can operate in a common frequency band with existing narrowband means of the short-wave range not creating them the substantial interference. The calculated signal/noise ratio on the input of the radio signals monitoring receiver is almost two orders less than for existing narrowband means of the short-wave range.