Error Probabilities for Spread-Spectrum Packet Radio with Convolutional Codes and Viterbi Decoding

The use of convolutional coding in packet radio systems introduces problems in evaluating performance, since the errors out of the decoder are not independent. A new bound on the packet error probability out of a Viterbi decoder may be used to evaluate these systems. We present results on the packet error probability for frequencyhop and direct-sequence spread-spectrum systems. In addition, we show that the assumption of independent errors out of the decoder gives an upper bound that is not as tight as our new bound. Comparisons are made with frequency-hop systems using Reed-Solomon codes.