Non-interacting complementary coding system

Claim 1

A two channel system comprising: first means for providing pluralities of coded sequences A and C in the first channel; second means for providing pluralities of coded sequences B and D in the second channel, each of said A, B, C and D coded sequences being of N bits in length; third and fourth means for respectively receiving said pluralities of coded sequences A and C in said first channel for respectively developing autocorrelation functions AA and CC and cross-correlation function AC; fifth and sixth means for respectively receiving said pluralities of coded sequences B and D in said second channel for respectively developing autocorrelation functions BB and DD and cross-correlation function BD, each of the functions AA, BB, CC, DD, AC and BD being of 2N-1 bits in length; seventh means coupled to said third and fifth means for summing corresponding terms of the functions AA, BB, AC and BD to develop a first output which Is zero for all corresponding terms except the Nth term; and eighth means coupled to said fourth and sixth means for summing corresponding terms of the functions CC, DD, AC and BD to develop a second output which is zero for all corresponding terms except the Nth term.

Claim 3

A system comprising: an acoustic structure having a surface with first and second ends and with first and second channels thereon providing transmission paths between said first and second ends; first and second data sources for respectively generating first and second pluralities of input digital signals; first and second input transducers in said first channel respectively positioned along the path near the first end and respectively coupled to said first and second data sources, said first and second input transducers being respectively responsive to each first and each second input digital signals for respectively developing first and second coded sequences therefrom; third and fourth input transducers in said second channel respectively positioned along the path near the first end and respectively coupled to said first and second data sources, said third and fourth input transducers being respectively responsive to each first and each second input digital signals for respectively developing third and fourth coded sequences therefrom; first and second output transducers in said first channel respectively positioned along the path near the second end to respectively develop the auto correlation functions of the first and second coded sequences; third and fourth output transducers in said second channel respectively positioned along the path near the second end to respectively develop the autocorrelation functions of the third and fourth coded sequences; first summing means coupled to said first and third output transducers for summing the autocorrelation functions of said first and third coded sequences to develop a first output digital signal for each input digital signal supplied by said first data source; and second summing means coupled to said second and fourth output transducers for summing the autocorrelation functions of said second and fourth coded sequences to develop a second output digital signal for each input digital signal supplied by said second data source, said first and third coded sequences being respectively non-interacting with said second and fourth coded sequences since the sum of the cross-correlation function of the first coded sequence developed in said second output transducer and the cross correlation function of the third coded sequence developed in said fourth output transducer is zero and since the sum of the cross-correlation function of the second coded sequence developed in said first output transducer and the cross correlation function of the fourth coded sequence developed in said third output transducer is zero.

Claim 4

A system comprising: an acoustic structure having a surface with first and second ends and with first and second channels thereon providing transmission paths between said first and second ends; first and second data sources for respectively generating first and second pluralities of input digital signals; first and second input transducers in said first channel respectively positioned along the path near the first end and respectively coupled to said first and second data sources, said first and second input transducers being respectively responsive to each first and each second input digital signals for respectively developing first and second coded sequences therefrom; third and fourth input transducers in said second channel respectively positioned along the path near the first end and respectively coupled to said first and second data sources, said third and fourth input transducers being respectively responsive to each first and each second input digital signals for respectively developing third and fourth coded sequences therefrom; first and second output transducers in said first channel respectively positioned along the path near the second end to respectively develop the auto correlation functions of the first and second coded sequences; third and fourth output transducers in said second channel respectively positioned along the path near the second end to respectively develop the autocorrelation functions of the third and fourth coded sequences; first summing means coupled to said first and third output transducers for summing the autocorrelation functions of said first and third coded sequences to develop a first output digital signal for each input digital signal supplied by said first data source; and second summing means coupled to said second and fourth output transducers for summing the autocorrelation functions of said second and fourth coded sequences to develop a second output digital signal for each input digital signal supplied by said second data source, said first and third coded sequences being respectively non-interacting with said second and fourth coded sequences since the sum of the cross-correlation function of the first coded sequence developed in said second output transducer and the cross correlation function of the third coded sequence developed in said fourth output transducer is zero and since the sum of the cross-correlation function of the second coded sequence developed in said first output transducer and the cross correlation function of the fourth coded sequence developed in said third output transducer is zero.

Claim 7

A system comprising: an acoustic structure providing first and second transmission paths between first and second positions; first and second means for respectively receiving first and second pluralities of input Digital signals; third and fourth means respectively positioned in the first and second transmission paths at the first position, said third and fourth means being coupled to said first means for respectively providing coded bit sequences A and B in response to each of the first plurality of input digital signals therefrom; fifth and sixth means respectively positioned adjacent to said third and fourth means in the first and second transmission paths near the first position, said fifth and sixth means being coupled to said second means for respectively providing coded bit sequences C and D in response to each of the second plurality of input digital signals therefrom; seventh and eighth means respectively positioned in the first and second transmission paths near the second position for respectively developing autocorrelation functions AA and BB and for respectively developing the cross correlation functions AC and BD, each of the functions AA, BB, AC and BD being 2N-1 terms in length; ninth and tenth means respectively positioned adjacent to said seventh and eighth means in the first and second transmission paths near the second position for respectively developing autocorrelation functions CC and DD and for respectively developing the cross-correlation functions AC and BD, each of the functions CC, DD, AC and BD being 2N-1 terms in length; eleventh means coupled to said seventh and eighth means for summing corresponding terms of the AA, BB, AC and BD functions to develop a first output which is zero for all corresponding 2N-1 terms except the Nth term, said eleventh means developing a first output for each of the first plurality of input signals; and twelfth means coupled to said ninth and tenth means for summing terms of the CC, DD, AC and BD functions to develop a second output which is zero for all corresponding 2N-1 terms except the Nth term, said twelfth means developing a second output for each of the second plurality of input signals.

Claim 8

A system comprising: an acoustic structure providing first and second transmission paths between first and second positions; first and second means for respectively receiving first and second pluralities of input Digital signals; third and fourth means respectively positioned in the first and second transmission paths at the first position, said third and fourth means being coupled to said first means for respectively providing coded bit sequences A and B in response to each of the first plurality of input digital signals therefrom; fifth and sixth means respectively positioned adjacent to said third and fourth means in the first and second transmission paths near the first position, said fifth and sixth means being coupled to said second means for respectively providing coded bit sequences C and D in response to each of the second plurality of input digital signals therefrom; seventh and eighth means respectively positioned in the first and second transmission paths near the second position for respectively developing autocorrelation functions AA and BB and for respectively developing the cross correlation functions AC and BD, each of the functions AA, BB, AC and BD being 2N-1 terms in length; ninth and tenth means respectively positioned adjacent to said seventh and eighth means in the first and second transmission paths near the second position for respectively developing autocorrelation functions CC and DD and for respectively developing the cross-correlation functions AC and BD, each of the functions CC, DD, AC and BD being 2N-1 terms in length; eleventh means coupled to said seventh and eighth means for summing corresponding terms of the AA, BB, AC and BD functions to develop a first output which is zero for all corresponding 2N-1 terms except the Nth term, said eleventh means developing a first output for each of the first plurality of input signals; and twelfth means coupled to said ninth and tenth means for summing terms of the CC, DD, AC and BD functions to develop a second output which is zero for all corresponding 2N-1 terms except the Nth term, said twelfth means developing a second output for each of the second plurality of input signals.