Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
224 words
A privacy signal transmission system comprising: a transmitter (100; 200) including digital pulse modulator means (1) for converting a first analog signal (Xi n ) into a first digital signal (X1), encryption means (2) for converting the first digital signal into a digital privacy signal (X 2 ), extractor means (10, 4) for extracting a first error signal (X 4 ) representative of a difference between a second analog signal (X 10 ) provided by analog conversion of the first digital signal (X 1 ) and the first analog signal (Xin), and transmission means (25, 7) for transmitting the first error signal (X 4 , X 5 ) and the first digital privacy signal (X 2 ); and a receiver (101; 201) including means (12,13,14,18, 19;23,19) for receiving the first error signal and the first digital privacy signal to individually generate a second error signal (X 19 ) and a second digital privacy signal (X 14 ), decryption means (15) for converting the second digital privacy signal into a second digital signal (X 15 ), digital pulse demodulator means (16) for converting the second digital signal (X 15 ) into a third analog signal (X 16 ), and reproduction means (20, 21) for reproducing the first analog signal by adding the error signal (X 19 ) to the third analog signal (X 16 ).
Claim 2
Dependent Claim
224 words
A privacy signal transmission system comprising: a transmitter (100; 200) including digital pulse modulator means (1) for converting a first analog signal (Xi n ) into a first digital signal (X1), encryption means (2) for converting the first digital signal into a digital privacy signal (X 2 ), extractor means (10, 4) for extracting a first error signal (X 4 ) representative of a difference between a second analog signal (X 10 ) provided by analog conversion of the first digital signal (X 1 ) and the first analog signal (Xin), and transmission means (25, 7) for transmitting the first error signal (X 4 , X 5 ) and the first digital privacy signal (X 2 ); and a receiver (101; 201) including means (12,13,14,18, 19;23,19) for receiving the first error signal and the first digital privacy signal to individually generate a second error signal (X 19 ) and a second digital privacy signal (X 14 ), decryption means (15) for converting the second digital privacy signal into a second digital signal (X 15 ), digital pulse demodulator means (16) for converting the second digital signal (X 15 ) into a third analog signal (X 16 ), and reproduction means (20, 21) for reproducing the first analog signal by adding the error signal (X 19 ) to the third analog signal (X 16 ).
Claim 3
Dependent Claim
19 words
A system as claimed in claim 1, in which the digital pulse modulator means comprises a ΔM modulator (1).
Claim 4
Dependent Claim
21 words
A system as claimed in claim 1 or 2, in which the digital pulse demodulator means comprises aAM demodulator means (16).
Claim 5
Independent Claim
69 words
A system as claimed in any one of claims 1 to 3, in which the transmission means (100) comprises frequency modulator means (3) for frequency-modulating a carrier with the first digital privacy signal (X 2 ), amplitude modulator means (6) for amplitude-modulating an output of said frequency modulator means (3) with the first error signal (XS) and means for transmitting an output of said amplitude modulator means (25, 7).
Claim 6
Independent Claim
70 words
A system as claimed in any one of claims 1 to 3, in which the transmission means (200) comprises amplitude modulator means (22) for amplitude-modulating the first digital privacy signal (X 2 ) with the first error signal (X5), frequency modulator means (3) for frequency-modulating a carrier with an output of said amplitude modulator means (22), and means (25, 7) for transmitting an output of said frequency modulator means (3).
Claim 7
Independent Claim
42 words
A system as claimed in any one of claims 1 to 5, in which the transmission means comprises means for phase-modulating the first digital privacy signal with the error signal, frequency-modulating a carrier with the phase-modulated signal, and transmitting said frequency-modulated signal.