Analysis of an error control protocol for spread spectrum communication networks

The authors evaluate the performance of spread spectrum multiple access packet radio networks under a simple hybrid-ARQ (automatic-repeat-request) scheme using convolutional encoding and Viterbi decoding with repeat request. This scheme can achieve improved reliability with only a slight degradation in throughput. A shorter length of chip sequences (or frequency hopping patterns) or a required smaller transmitting power can be implemented under this scheme while still accomplishing the desired reliability. The retransmission and additional delay can be controlled by adjusting a threshold level. This hybrid scheme offers a more flexible set of parameters from which individual users can choose. The evaluation of packet error probability, throughput, and delay is investigated and numerically presented