The effect of automatic gain control on the performance of matched-filter packet acquisition using dual antenna diversity

The performance of serial acquisition is evaluated for direct-sequence spread-spectrum packet radio communications using dual antenna transmissions with orthogonal preamble sequences. Non-coherent diversity combining of the outputs from a corresponding pair of preamble matched filters is considered in conjunction with threshold-based acquisition using both fixed and adaptive acquisition thresholds. The effect of the intermediate-frequency filter and the automatic gain control subsystem on the acquisition performance is addressed, and the performance is evaluated in a slow fading channel. The effect of fixed and adaptive acquisition thresholds on the link outage probability is compared for the dual antenna system, and both are compared with the outage probability in a single antenna system.