In the paper a new go-back-Nscheme for communication systems using error-detecting codes is described. This scheme has a buffer at the receiver side in order to introduce a memory into the go-back-Nprotocol. This memory and a soft demodulation of each received symbol significantly increase the performance of classical go-back-Nschemes. It is also shown that, for mean and high error rate conditions, the scheme proposed has a higher throughput than the selective scheme and, at the same time, a lower implementation conplexity.