Frequency-hopped single sideband mobile radio system

A transmitter (10) for communicating a message signal (s(t)) wherein said transmitter is responsive to said message signal for producing as an output a carrier-frequency-hopped single sideband signal s'.sub.hop (t)), wherein said transmitter comprises

• carrier-frequency-hopping generating means (16) for generating as an output a unique sequence of separate carrier frequencies (f.sub.i (t)) from a plurality of N possible carrier frequencies;
• and
• multiplying means (12, 14, 18) responsive to both said message signal and said unique sequence of separate carrier frequencies for multiplying said message signal with said unique sequence of carrier frequencies and producing as an output of said transmitter the carrier-frequency-hopped single sideband signal, where the multiplying means comprises
• a first bandpass filter (12) responsive to the message signal for producing as an output a filtered message signal r(t) equal to the portion of said message signal appearing in a predetermined frequency range (f.sub.a -f.sub.b);
• a multiplier (14) responsive to both said filtered message signal and the unique sequence of separate carrier frequencies for producing as an output a carrier-frequency-hopped message signal (S.sub.hop (t)) equal to the multiplicative produce thereof;
• and
• a second bandpass filter (18) responsive to both said carrier-frequency-hopped message signal and said unique sequence of separate carrier frequencies for removing unwanted components from said carrier-frequency-hopped message signal and producing as an output of said transmitter the carrier-frequency-hopped single sideband signal (s'.sub.hop (t)).

A receiver (20) capable of receiving and demodulating a carrier-frequency-hopped single sideband signal (s'.sub.hop (t)) and recovering therefrom a message signal (s(t)) wherein the receiver comprises

• carrier-frequency-hopping generating means (24) for generating as an output a unique sequence of separate carrier frequencies relates to the received carrier-frequency-hopped single sideband signal;
• and
• demodulating means (22, 26, 28) responsive to both said received carrier-frequency-hopped single sideband signal and said unique sequence of separate carrier frequencies for demodulating said received carrier-frequency-hopped single sideband signal in accordance with said unique sequence of separate carrier frequencies and producing as an output of said receiver the message signal related thereto, wherein the demodulating means comprises
• a first bandpass filter (22) responsive to both the received carrier-frequency-hopped single sideband signal and the unique sequence of carrier frequencies for producing as an output a filtered carrier-frequency-hopped single sideband signal (r(t));
• a multiplier (26) responsive to both said filtered carrier-frequency-hopped single sideband signal and said unique sequence of carrier frequencies for producing as an output a multiplicative product thereof (d(t));
• and
• a second bandpass filter (28) responsive to said multiplicative product signal for removing unwanted components therefrom and producing as an output of said receiver the message signal related thereto.