A lattice-based scheme for the single-frame and the double-frame quantization of the speech line spectral frequency parameters is proposed. The lattice structure provides a low-complexity vector quantization framework, which is implemented using a trellis structure. In the single-frame scheme, the intraframe dependencies are exploited using a linear predictor. In the double-frame scheme, the parameters of two consecutive frames are jointly quantized and hence the interframe dependencies are also exploited. A switched scheme is also considered in which, lattice-based double-frame and single-frame quantization is performed for each two frame and the one which results in a lower distortion is chosen. Comparisons to the Split-VQ, the Multi-Stage VQ, the Trellis Coded Quantization, the interframe Block-Based Trellis Quantizer, and the interframe scheme used in IS-641 EFRC and the GSM AMR codec are provided. These results demonstrate the effectiveness of the proposed lattice-based quantization schemes, while maintaining a very low complexity. Finally, the issue of the robustness to channel errors is investigated

We present a scheme for single frame (20 msec) and double frame (40 msec) quantization of line spectral frequency (LSF) parameters in a code-excited linear prediction (CELP) speech coder using noise feedback coding. To improve the performance, an appropriate lattice structure is used as the quantizer in the noise feedback loop. We also consider a switched structure based on using either a double frame quantizer or two single frame quantizers for two subsequent frames where an extra bit is used to specify the choice offering a lower distortion. Numerical results are presented showing an excellent performance with very low complexity.