This paper describes a new speech coder at 600 bps based on the enhanced mixed excitation linear prediction (MELPE) algorithm, which is the new NATO standard STANAG 4591. The algorithm of this speech coder includes features of MELPE. Multi-frame joint vector quantification is performed, which takes advantage of inherent inter-frame redundancy. The predicted multi-stage vector quantization (PMSVQ) algorithm is designed to quantize the line spectrum frequency (LSF) parameters. The informal subjective quality tests show that the speech quality of the proposed coder is better than that of LPC10e and approximates to 2.4 kbps MELP standard.