Upper Limits on the Performance of the Optimum Processor in Mismatched Environment

In most signal detection problems, information about the observations is not precisely known beforehand. The performance of the likelihood ratio processor (LRP), designed according to a preassumed observation vector parameter, is investigated when the actual processed observations have a vector parameter that differs from the preassumed design vector parameter. An upper limit on the performance of the LRP is obtained when the actual and design vector parameters are equal. The possible need for using adaptive processors is determined by this LRP performance investigation.