A system and method for determining a transport format of a transport channel is described. A guiding stream is received on a guiding transport channel and a guided stream is received on a guided transport channel. The guided stream is convolutionally decoded to produce a plurality of Viterbi path metrics. A transport format for the guided transport channel is selected from possible transport formats. The possible transport formats are determined by information provided on the guiding transport channel. The selection of the transport format is based at least in part on a metric computed from a combination of the Viterbi path metrics.