A robust adaptive array processor

A post-beam-former interference canceller (PIC) processes the signals derived from an antenna array by forming two beams using fixed beam-forming weights. The weighted output of the one beam, referred to as the interference beam, is subtracted from the other beam, referred to as the signal beam, which has a specified response in the signal direction. This paper presents an algorithm to adjust the complex weight of the interference channel iteratively, studies its convergence, presents an exact expression for the misadjustment, and compares the performance of this processor with that of an element space processor. The paper shows that in the absence of errors the performance of the two processors is identical but in the presence of the signal direction error the PIC processor performs better than the element space processor. Furthermore, the adaptive algorithm of the PIC needs to adjust only one complex weight per iteration, whereas in the element space processor the number of complex weights required to be updated at each iteration is equal to the number of elements in the array.