Deep-space Ka-band link priority data protection: pre-emptive retransmission vs. margin

Abstract

In this paper the performance of two preemptive retransmission schemes for protection of priority data over deep-space Ka-band lnks is evaluated. The first scheme merges the correctly received bit from each transmission to create the most complete set of priority data for each pass (bit merge). The second scheme (symbol combining) combines the soft symbols received from each transmission of the priority data to increase the priority data's signal to noise ratio (SNR), thus increasing the liklihood of the correct reception.