Adaptive system for broadband multisignal discrimination in a channel with reverberation

A method for recovering at least one of a plurality I of source signals {S.sub.i } in a communications system, wherein each said source signal S.sub.i arrives at a receiver from one of a plurality J of directions {D.sub.j }, said receiver including a plurality K of sensors each having a sensor output signal E.sub.k, where i, j and k are nonzero positive integers and I, J and K are positive integers greater than unity, said method comprising:

• creating a plurality K of said sensor output signals {E.sub.k } in response to said plurality I of source signals {S.sub.i };
• creating a plurality J of spatial beam signals {B.sub.j } in response to said sensor output signals {E.sub.k } such that ##EQU20## wherein t is time and .beta..sub.kj, b.sub.k and .lambda..sub.k are predetermined constants;
• and
• producing one or more of said estimated source signals {Y.sub.i } in response to said plurality a of spatial beam signals {B.sub.j } and a plurality I.J of transform signals {c.sub.ji }, wherein each estimated source signal Y.sub.i corresponds to one of said source signals {S.sub.i } and said plurality I.J of transform signals {c.sub.ij } corresponds to a transform matrix updated by successive approximation of a plurality I of estimated source signals {Y.sub.i } and by successive addition to each said transform signal c.sub.ji of an increment signal .DELTA.C.sub.ji =(-.mu.)f(Y.sub.j)g(Y.sub.i), wherein [Y.sub.j ]=[II+C.sub.ji ].sup.-1 [B.sub.j ], [II] is the unit matrix, .mu. is a predetermined constant and f(x) and g(x) are predetermined odd functions of x.

A method for recovering at least one of a plurality I of source signals {S.sub.i }, each said source signal S.sub.i arriving at a receiver from one of a plurality J of directions {D.sub.j }, said receiver including a plurality K of sensors each having a sensor output signal E.sub.k, wherein i, j and k are nonzero positive integers and I, J and K are positive integers greater than unity, said method comprising:

• creating a plurality K of said sensor output signals {E.sub.k } responsive to said plurality I of source signals {S.sub.i };
• multiplying said sensor output signals {E.sub.k } by predetermined shading factors {b.sub.k } to create a plurality K of shaded sensor output signals {b.sub.k E.sub.k };
• delaying said shaded sensor output signals {b.sub.k E.sub.k } by means of a plurality J of phasing vectors [.beta..sub.k ].sub.i to produce a plurality J.multidot.K of delayed shaded sensor output signals [b.sub.k E.sub.k ].sub.j and combining said delayed shaded sensor output signals to create a plurality J of spatial beam signals {B.sub.j };
• and
• repeatedly performing the steps of
• combining said spatial beam signals {B.sub.j } to create a plurality I of estimated source signals {Y.sub.i } so that [Y.sub.i ]=[II+C.sub.ji ].sup.-1 [B.sub.j ], wherein [II] is the unit matrix and [C.sub.ji ] is an adaptive transform matrix corresponding to a plurality J.multidot.K of transform signals {c.sub.ji };
• adjusting said transform signals {c.sub.ji } in response to said estimated source signals {Y.sub.i } to correct said adaptive transform matrix [C.sub.ji ];
• and
• producing at least one of said estimated source signals {Y.sub.i }, wherein said produced estimated source signal corresponds to said at least one of said source signals {S.sub.i }.

A system for separating a plurality I of source signals {S.sub.i }, each said source signal S.sub.i arriving from one of a plurality J of directions {D.sub.j }, said system comprising:

• sensor array means having a plurality K of sensors for receiving said source signals {S.sub.i };
• transducer means in each sensor for creating a sensor output signal E.sub.k in response to plurality I of source signals {S.sub.i };
• beamformer means coupled to said sensor array means for creating a plurality J of spatial beam signals {B.sub.j } in response to said plurality K of sensor output signals {E.sub.k };
• broadband shading means coupled to said sensor array means for adjusting said plurality K of sensor output signals {E.sub.k } over a predetermined frequency band for equalizing the amplitude response of said sensor array means over said predetermined frequency band;
• and
• output means coupled to said beamformer means and said broadband shading means for generating a plurality I of output signals {Y.sub.i } corresponding to estimates of said source signals {S.sub.i }, wherein i, j and k are nonzero positive integers and I, J and K are positive integers greater than unity.

A system for separating a plurality I of source signals {S.sub.i }, each said source signal S.sub.i arriving from one of a plurality J of directions {D.sub.j }, said system comprising:

• sensor array means having a plurality K of sensors for receiving said source signals {S.sub.i };
• transducer means in each sensor for creating a sensor output signal E.sub.k in response to said plurality I of source signals {S.sub.i };
• beamformer means coupled to said sensor array means for creating a plurality J of spatial beam signals {B.sub.j } in response to said plurality K of sensor output signals {E.sub.k };
• transform means coupled to said beamformer means for creating and storing a plurality I.J of transform signals {c.sub.ji } corresponding to an adaptive transform matrix [C.sub.ji ];
• output means coupled to said beamformer means and said transform means for generating a plurality I of output signals {Y.sub.i } corresponding to estimates of said source signals {S.sub.i } such that [Y.sub.i ]=[II+C.sub.ji ].sup.- [B.sub.j ], wherein [II] is the unit matrix;
• and
• adaptive transform means coupled to said output means and said transform means for adjusting each of said plurality I.J of transform signals {c.sub.ji } in response to an increment signal .DELTA.c.sub.ji =(.mu.)f(Y.sub.j)g(Y.sub.i), wherein .mu. is a predetermined constant and f(x) and g(x) are predetermined odd functions of x, wherein i, j and k are nonzero positive integers and I, J and K are positive integers greater than unity.

A system for adaptive cancellation of one or more interferer signals {S.sub.i } in a signal receiver having a sensor array with a plurality K of sensors, said system comprising:

• transducer means in each sensor for creating a sensor output signal E.sub.k in response to a plurality 1 of said interferer signals {S.sub.i };
• beamformer means coupled to said sensor array for creating a plurality J of spatial beam signals {B.sub.j } in response to said plurality K of sensor output signals {E.sub.k };
• transform means coupled to said beamformer means for creating and storing a plurality I.J of transform signals {c.sub.ji .sub. } corresponding to an adaptive transform matrix [C.sub.ji ];
• output means coupled to said beamformer means and said transform means for signals {S.sub.i } such that [Y.sub.i ]=[II+C.sub.ji ].sup.-1 [B.sub.j ], wherein [II] is the unit matrix;
• and
• adaptive transform means coupled to said output means and said transform means for adjusting each of said plurality I.J of transform signals {c.sub.ji } in response to an increment signal .DELTA.c.sub.ji =(.mu.)f(Y.sub.j)g(Y.sub.i), wherein f(x) and g(x) are predetermined odd functions of x,.mu. is a predetermined constant, i, j and k are nonzero positive integers and I, J and K are positive integers greater than unity.

A system for separating a plurality 1 of source signals {S.sub.i } in an underwater acoustic communications system, each said source signal S.sub.i arriving from one of a plurality J of directions {D.sub.j }, said system comprising:

• sensor array means having a plurality K of acoustic sensors for receiving said plurality I of source signals {S.sub.i };
• transducer means in each acoustic sensor for creating a sensor output signal E.sub.k in response to said plurality I of source signals {S.sub.i };
• beamformer means coupled to said sensor array means for creating a plurality J of spatial beam signals {B.sub.j } in response to said plurality K of sensor output signals {E.sub.k };
• transform means coupled to said beamformer means for creating and storing a plurality I.J of transform signals {c.sub.ji } corresponding to an adaptive transform matrix [C.sub.ji ];
• output means coupled to said beamformer means and said transform means for generating a plurality I of output signals {Y.sub.i } corresponding to estimates of said source signals {S.sub.i } such that [Y.sub.i ]=[II+C.sub.ji ].sup.-1 [B.sub.j ], wherein [II] is the unit matrix;
• and
• adaptive transform means coupled to said output means and said transform means for adjusting each of said plurality I.J of transform signals {c.sub.ji } in response to an increment signal .DELTA.C.sub.ji =(.mu.)f(Y.sub.j)g(Y.sub.i), wherein f(x) and g(x) are predetermined odd functions of x,.mu. is a predetermined constant, i, j and k are nonzero positive integers and I, J and K are positive integers greater than unity.

A system for separating a plurality I of source signals {S.sub.i } in a cellular telecommunication system, each said source signal S.sub.i arriving from one of a plurality J of directions {D.sub.j }, said system comprising:

• sensor array means having a plurality K of antenna elements for receiving said plurality I of source signals {S.sub.i };
• transducer means in each antenna element for creating a sensor output signal E.sub.k in response to said plurality I of source signals {S.sub.i };
• beamformer means coupled to said sensor array means for creating a plurality J of spatial beam signals {B.sub.j } in response to said plurality K of sensor output signals {E.sub.k };
• transform means coupled to said beamformer means for creating and storing a plurality I.J of transform signals {c.sub.ji } corresponding to an adaptive transform matrix [C.sub.ji ];
• output means coupled to said beamformer means and said transform means for generating a plurality I of output signals {Y.sub.i } corresponding to estimates of said source signals {S.sub.i } such that [Y.sub.i ]=[II+C.sub.ji ].sup.-1 [B.sub.j ], wherein [II] is the unit matrix;
• and
• adaptive transform means coupled to said output means and said transform means for adjusting each of said plurality I.J of transform signals {c.sub.ji } in response to an increment signal .DELTA.c.sub.ji =(.mu.)f(Y.sub.i)g(Y.sub.i), wherein f(x) and g(x) are predetermined odd functions of x, .mu. is a predetermined constant, i, j and k are nonzero positive integers and I, J and K are positive integers greater than unity.