System and method for bandwidth compression of frequency and phase modulated signals by suppression of the upper and lower sidebands from the transmission medium

A receiver for receiving and processing narrow band or very narrow band frequency-modulated information signals with suppressed upper and lower sidebands that have a predetermined small or very small frequency deviation due to compression of transmitted signals, and that have been transmitted over a narrow band or very narrow band communication channel, the receiver comprising:

• means for receiving from the communication channel the narrow band or very narrow band frequency-modulated information signals with the suppressed upper and lower sidebands, said narrow band or very narrow band frequency-modulated information signals with the suppressed upper and lower sidebands having the predetermined small or very small frequency deviation;
• and
• a circuit that expands the predetermined small or very small predetermined frequency deviation of the received narrow band or very narrow band frequency-modulated information signals with the suppressed upper and lower sidebands.

A transmitter for transmitting an information signal via a communication channel connecting a transmitting side and a receiving side, involving frequency modulation with a modulation index M that is not greater than 0.2 to thus compress a bandwidth of the information signal to have a small or very small frequency deviation at the transmitting side of the communication channel and in the communication channel, the transmitter comprising:

• means for frequency modulating an information signal with a modulation index M that is not greater than 0.2 to compress a bandwidth of the information signal to form a narrow band or very narrow band frequency-modulated information signal having a small or very small frequency deviation at the transmitting side of a narrow or very narrow band communication channel and in said communication channel;
• and
• means for suppressing upper and lower sidebands of the narrow band or very narrow band frequency-modulated information signal prior to transmission.

A receiver for receiving and processing narrow band or very narrow band phase modulated information signals with suppressed upper and lower sidebands that have a predetermined small or very small frequency deviation due to compression of transmitted signals, and that have been transmitted over a narrow band or very narrow band communication channel, the receiver comprising:

• means for receiving from the communication channel the narrow band or very narrow band phase-modulated information signals with the suppressed upper and lower sidebands, said narrow band or very narrow band phase-modulated information signals with the suppressed upper and lower sidebands having the predetermined small or very small frequency deviation;
• and
• a circuit that expands the predetermined small or very small predetermined frequency deviation of the received narrow band or very narrow band phase-modulated information signals with the suppressed upper and lower sidebands.

A transmitter for transmitting an information signal via a communication channel connecting a transmitting side and a receiving side, involving phase modulation with a modulation index M that is not greater than 0.2 to thus compress a bandwidth of the information signal to have a small or very small frequency deviation at the transmitting side of the communication channel and in the communication channel, the transmitter comprising:

• means for phase modulating an information signal with a modulation index M that is not greater than 0.2 to compress a bandwidth of the information signal to form a narrow band or very narrow band phase-modulated information signal having a small or very small frequency deviation at the transmitting side of a narrow or very narrow band communication channel and in said communication channel;
• and
• means for suppressing upper and lower sidebands of the narrow band or very narrow band phase-modulated information signal prior to transmission.