Effect of Errors in Adaptive Weights

Optimum weighting is used to adaptively increase the signal-to-interference ratio (SIR) of signal processors. The precision required in computing the weights is evaluated. Analytic results have been obtained and verified by computer simulation. lt is shown that for antenna adaptivity the required weight precision increases with increasing values of the attainable SIR improvement and with the number of auxiliary elements. A typical result is that when using 8 auxiliary elements with a theoretical SIR improvement of 40 dB, quantizing the optimum weights to 10 bits degrades the improvement by at most 3 dB.