Spread spectrum signal

A method of receiving a spread spectrum signal, comprising:

• receiving incoming electromagnetic waves of said spread spectrum signal, said spread spectrum signal comprising a carrier wave and at least one spreading waveform, which modulates said carrier wave;
• said spreading waveform comprising a real linear combination of a first binary waveform at a first waveform rate and a second binary waveform at a second waveform rate;
• said first waveform rate being distinct from said second waveform rate and both waveform rates being non-zero;
• said linear combination being modulated with a binary sequence comprising a signal identification code and said modulated linear combination being of the form
• [α·w1(t)+β·w2(t)]·PRN(t),
• where t represents a time variable, w1(t) said first binary waveform, w2(t) said second binary waveform, α and β non-zero coefficients and PRN(t) said binary sequence comprising the signal identification code;
• generating a local code replica of said binary sequence;
• generating a local replica of said first waveform;
• generating a local replica of said second waveform;
• performing a linear combination of said local replica of said first waveform with said local replica of said second waveform;
• and
• correlating said incoming electromagnetic waves with said linear combination of local replicas and said local code replica.

A receiver for receiving a spread-spectrum signal, comprising:

• an input device to receive incoming electromagnetic waves of said spread spectrum signal, said spread spectrum signal comprising a carrier wave and at least one spreading waveform, which modulates said carrier wave;
• said spreading waveform comprising a real linear combination of a first binary waveform at a first waveform rate and a second binary waveform at a second waveform rate;
• said first waveform rate being distinct from said second waveform rate and both waveform rates being non-zero;
• said linear combination being modulated with a binary sequence comprising a signal identification code and said modulated linear combination being of the form
• [α·w1(t)+β·w2(t)]·PRN(t),
• where t represents a time variable, w1(t) said first binary waveform, w2(t) said second binary waveform, α and β non-zero coefficients and PRN(t) said binary sequence comprising the signal identification code;
• a code generator generating a local code replica of said binary sequence;
• a first waveform generator generating a local replica of said first waveform;
• a second waveform generator generating a local replica of said second waveform;
• a correlator correlating said incoming electromagnetic waves with said local replica of the first waveform and said local code replica so as to form a first correlation result;
• a correlator correlating said incoming electromagnetic waves with said local replica of the second waveform and said local code replica so as to form a second correlation result;
• and
• a combiner linearly combining said first and second correlation results.

A receiver for receiving a spread-spectrum signal, comprising:

• an input device to receive incoming electromagnetic waves of said spread spectrum signal;
• said spread spectrum signal comprising a carrier wave and at least one spreading waveform, which modulates said carrier wave;
• said spreading waveform comprising a real linear combination of a first binary waveform at a first waveform rate and a second binary waveform at a second waveform rate;
• said first waveform rate being distinct from said second waveform rate and both waveform rates being non-zero;
• said linear combination being modulated with a binary sequence comprising a signal identification code and said modulated linear combination being of the form
• [α·w1(t)+β·w2(t)]·PRN(t),
• where t represents a time variable, w1(t) said first binary waveform, w2(t) said second binary waveform, α and β non-zero coefficients and PRN(t) said binary sequence comprising the signal identification code;
• a code generator generating a local code replica of said binary sequence;
• a first waveform generator generating a local replica of said first waveform;
• a second waveform generator generating a local replica of said second waveform;
• a combiner forming a linear combination of said local replica of the first waveform and said local replica of the second waveform;
• and
• a correlator correlating said incoming electromagnetic waves with said linear combination of local replicas and said local code replica.

A method for producing a spread-spectrum signal, said spread spectrum signal comprising a carrier wave and at least one spreading waveform, which modulates said carrier wave;

• said spreading waveform comprising a real linear combination of a first binary waveform at a first waveform rate and a second binary waveform at a second waveform rate;
• said first waveform rate being distinct from said second waveform rate and both waveform rates being non-zero;
• said linear combination being modulated with a binary sequence comprising a signal identification code and said modulated linear combination being of the form
• [α·w1(t)+β·w2(t)]·PRN(t),
• where t represents a time variable, w1(t) said first binary waveform, w2(t) said second binary waveform, α and β non-zero coefficients and PRN(t) said binary sequence comprising the signal identification code;
• said method comprising:
• providing a carrier wave;
• providing a spreading waveform, said providing a spreading waveform including:
• providing a first waveform at said first waveform rate and a second waveform at said second waveform rate;
• said first waveform rate being distinct from said second waveform rate;
• providing a binary sequence comprising at least one signal identification code;
• forming a modulated linear combination of said first waveform and said second waveform, said modulated linear combination being of the form
• [α·w1(t)+β·w2(t)]·PRN(t),
• where t represents a time variable, w1(t) said first binary waveform, w2(t) said second binary waveform, α and β non-zero coefficients and PRN(t) said binary sequence comprising the signal identification code;
• and
• modulating the carrier wave with said spreading waveform.

A navigation signal system comprising:

• a receiver configured to receive a spread-spectrum signal, said spread spectrum signal comprising a carrier wave and at least one spreading waveform, which modulates said carrier wave;
• said spreading waveform comprising a real linear combination of a first binary waveform at a first waveform rate and a second binary waveform at a second waveform rate;
• said first waveform rate being distinct from said second waveform rate and both waveform rates being non-zero;
• said linear combination being modulated with a binary sequence comprising a signal identification code and said modulated linear combination being of the form
• [α·w1(t)+β·w2(t)]·PRN(t),
• where t represents a time variable, w1(t) said first binary waveform, w2(t) said second binary waveform, α and β non-zero coefficients and PRN(t) said binary sequence comprising the signal identification code;
• and said first waveform being a BOC(1, 1) and said second waveform is a binary waveform having a rate selected among 10.23 Mcps, 12.276 Mcps, 15.345 Mcps and 30.69 Mcps.

A system to receive a spread-spectrum signal, said system comprising:

• a signal generator configured to generate said spread spectrum signal, said spread spectrum signal comprising a carrier wave and at least one spreading waveform, which modulates said carrier wave,
• wherein said spreading waveform comprises a real linear combination of a first binary waveform at a first waveform rate and a second binary waveform at a second waveform rate;
• said first waveform rate being distinct from said second waveform rate and both waveform rates being non-zero;
• said linear combination being modulated with a binary sequence comprising a signal identification code and
• said modulated linear combination being of the form
• [α·w1(t)+β·w2(t)]·PRN(t),
• where t represents a time variable, w1(t) said first binary waveform, w2(t) said second binary waveform, α and β non-zero coefficients and PRN(t) said binary sequence comprising the signal identification code;
• and
• a receiver to receive said spread spectrum signal.