Beamforming/null-steering adaptive array

• US 4,651,155 A
• Filed: 05/28/1982
• Issued: 03/17/1987
• Est. Priority Date: 05/28/1982
• Status: Expired due to Term

• Current Assignee: Hazeltine Corporation (BAE Systems Plc)
• Original Assignee: Hazeltine Corporation (BAE Systems Plc)
• Inventors: Masak, Raymond J., Baurle, Herbert F.
• Primary Examiner(s): Blum, Theodore M.
• Assistant Examiner(s): Barron, Jr., Gilberto
• Application Number:
  US06/383,036
• Time in Patent Office: 1,754 Days
• Field of Search: 343/370, 343/374, 343/368, 343/379-384, 343/378, 455/278, 455/279, 455/296, 455/305, 455/306, 375/99, 375/102
• US Class Current: 342/378
• CPC Class Codes: H01Q 3/2617 Array of identical elements

Abstract

A beamforming adaptive control loop is simultaneously employed in combination with a null-steering adaptive control loop to enhance the signal/interference ratio resulting in an increase in the message quality. The loops employ spectral processing in which case bandpass filters and notch filters form separate loops which enhance the desired signals and cancel the undesired signals, respectively. The correlated output from the beamforming loop is added to the correlated output of the null-steering loop and mixed with the incoming signal.

Claims

1. An apparatus for cancelling undesired signals received with a desired signal, said apparatus comprising:

(a) first means for providing the desired and any undesired signals received with the desired signal;

(b) a first adaptive control loop coupled to said first means, said first loop having a negative correcting output for minimizing the undesired signal;

(c) a second adaptive control loop coupled to the first means, said second loop having a positive correcting output for maximizing the desired signal;

(d) second means for summing the negative correcting output and the positive correcting output and providing a sum signal corresponding thereto;

(e) a mixer for mixing the desired and any undesired signals with the sum signal to provide a mixed output;

(f) said first adaptive control loop further comprising a first notch filter circuit coupled to the first means and providing a notch unmixed output, a second notched circuit coupled to the mixed output and providing a notch mixed output and a notch correlator correlating the notch unmixed output with the notch mixed output, said notch correlator providing the negative correcting output;

(g) said second adaptive control loop further comprising a first bandpass filter circuit coupled to the first means and providing a bandpass unmixed output, a second bandpass filter circuit coupled to the mixed output and providing a bandpass mixed output and a bandpass correlator correlating the bandpass unmixed output with the bandpass mixed output, said bandpass correlator providing the positive correcting output.

2. The apparatus of claim 1 wherein said bandpass correlator comprises:

(1) a first mixer for mixing the bandpass unmixed output and the bandpass mixed output and providing a first mixer output; and

(2) a first integrator for integrating the first mixer output and providing the integrated first mixer output to the second means as the positive correcting output;

and wherein said notch correlator comprises;

(1) a second mixer for mixing the notch unmixed output and the notch mixed output providing a second mixer output; and

(2) a second integrator for integrating the second mixer output and providing the integrated second mixer output to the second means as the negative connecting output.

3. The apparatus of claim 1 further including means for code correlating the vector components of the desired signal so that the resultant coded signal vector provided by said first means includes the desired signal transformed into a narrow band form and the undesired signal maintained in a wideband form.