Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
335 words
A bidirectional data transmission system for transmitting first and second data signals using the technique known as spectrum spreading by direct sequence, comprising first and second transmitter-receiver assemblies, said first transmitter-receiver assembly comprising a first transmitter section including an input for said first data, a first code generator for producing a spreading code having a delay modulated under the control of said first data, means for producing a radioelectrical carrier, and a first modulator for modulating said carrier by said spreading code to provide a coded first data signal for transmission, and a first receiver section for receiving a coded second data signal transmitted from said second transmitter receiver assembly and restoring said second data from said received coded second data signal, said first receiver section including a mixer for mixing said received coded second data signal with said coded first data signal, and means for demodulating the output from said mixer to provide said restored second data, and said second transmitter-receiver assembly comprising a second transmitter section including an input for said second data, means for producing a transmission carrier modulated by said second data, a second code generator for producing a spreading code having a delay, said second code generator also producing an alternating signal, and a second modulator for modulating said transmission carrier by said spreading code produced by said second code generator to provide said coded second data signal for transmission, and a second receiver section for receiving said coded first data signal transmitted from said first transmitter-receiver assembly and restoring said first data by demodulation of the spreading code delay contained in said coded first data signal, said second receiver section including means for correlating the received coded first data signal with said coded second data signal, and a synchronous detector which receives the output from said correlating means and also said alternating signal to provide said restored first data, said restored first data being used to control said delay of said spreading code produced by said second code generator.
Claim 2
Dependent Claim
335 words
A bidirectional data transmission system for transmitting first and second data signals using the technique known as spectrum spreading by direct sequence, comprising first and second transmitter-receiver assemblies, said first transmitter-receiver assembly comprising a first transmitter section including an input for said first data, a first code generator for producing a spreading code having a delay modulated under the control of said first data, means for producing a radioelectrical carrier, and a first modulator for modulating said carrier by said spreading code to provide a coded first data signal for transmission, and a first receiver section for receiving a coded second data signal transmitted from said second transmitter receiver assembly and restoring said second data from said received coded second data signal, said first receiver section including a mixer for mixing said received coded second data signal with said coded first data signal, and means for demodulating the output from said mixer to provide said restored second data, and said second transmitter-receiver assembly comprising a second transmitter section including an input for said second data, means for producing a transmission carrier modulated by said second data, a second code generator for producing a spreading code having a delay, said second code generator also producing an alternating signal, and a second modulator for modulating said transmission carrier by said spreading code produced by said second code generator to provide said coded second data signal for transmission, and a second receiver section for receiving said coded first data signal transmitted from said first transmitter-receiver assembly and restoring said first data by demodulation of the spreading code delay contained in said coded first data signal, said second receiver section including means for correlating the received coded first data signal with said coded second data signal, and a synchronous detector which receives the output from said correlating means and also said alternating signal to provide said restored first data, said restored first data being used to control said delay of said spreading code produced by said second code generator.
Claim 3
Dependent Claim
55 words
A transmission system according to claim 1, wherein said first transmitter section of said first transmitter-receiver assembly includes a voltage controlled oscillator, and the delay modulation of said spreading code produced by said first transmitter-receiver assembly is effected by modification of the frequency of said voltage controlled oscillator under the control of said first data.
Claim 4
Dependent Claim
44 words
A transmission system according to claim 1, wherein the delay modulation of said spreading code produced by said first transmitter-receiver assembly is effected by modification of the delay of the code delivered by said first code generator under the control of said first data.
Claim 5
Dependent Claim
64 words
A transmission system according to claim 1, wherein the spreading code of said first transmitter-receiver assembly is composed of two alternately used pseudo-random binary semi-sequences of period T/2 and having nil or virtually nil inter-correlation, and the spreading code of said second transmitter-receiver assembly is composed of the same half sequences, one of which is affected by an offset corresponding to a circular rotation.
Claim 6
Dependent Claim
24 words
A transmission system according to claim 1, wherein said radioelectrical carrier of said first transmitter-receiver assembly is produced by a fixed frequency local oscillator.
Claim 7
Dependent Claim
35 words
A transmission system according to claim 5, wherein said transmission carrier of said second transmitter-receiver assembly is produced by an oscillator of which the frequency can be modified under the control of said second data.
Claim 8
Dependent Claim
33 words
A transmission system according to claim 1, wherein said radioelectrical carrier of said first transmitter-receiver assembly is produced by a first frequency synthesizer from a voltage controlled oscillator controlled by said first data.
Claim 9
Dependent Claim
47 words
A transmission system according to claim 7, wherein said transmission carrier of said second transmitter-receiver assembly is produced by a second frequency synthesizer from a voltage controlled oscillator controlled by said restored first data, said second frequency synthesizer also receiving said second data as a modulating input.
Claim 10
Dependent Claim
24 words
A transmission system according to claim 1, wherein said first and second modulators are of the type having two phase states, for example O-π.