In a transmit method, a set of data eigenvectors that are based on a Prometheus Orthonormal Set (PONS) code construction and orthogonal to each other are stored, wherein each of the data eigenvectors is mapped to a unique multi-bit word. A pilot sequence representing a pilot eigenvector that is based on the PONS code construction and orthogonal to each of the data eigenvectors is generated. Input data is grouped into multi-bit words and ones of the data eigenvectors mapped to the multi-bit words are selected. A spread data sequence including the selected ones of the data eigenvectors and that is synchronized to the pilot sequence is generated. An acoustic signal including the synchronized pilot sequence and the spread data sequence is generated. The acoustic signal is transmitted.

In a transmit method, a set of data eigenvectors that are based on a Prometheus Orthonormal Set (PONS) code construction and orthogonal to each other are stored, wherein each of the data eigenvectors is mapped to a unique multi-bit word. A pilot sequence representing a pilot eigenvector that is based on the PONS code construction and orthogonal to each of the data eigenvectors is generated. Input data is grouped into multi-bit words and ones of the data eigenvectors mapped to the multi-bit words are selected. A spread data sequence including the selected ones of the data eigenvectors and that is synchronized to the pilot sequence is generated. An acoustic signal including the synchronized pilot sequence and the spread data sequence is generated. The acoustic signal is transmitted.

The invention relates to an encoder and a decoder and methods therein for supporting split gain shape vector encoding and decoding. The method performed by an encoder, where the encoding of each vector segment is subjected to a constraint related to a maximum number of bits, B.sub.MAX, allowed for encoding a vector segment. The method comprises, determining an initial number, Np_.sub.init, of segments for a target vector x; and further determining an average number of bits per segment, B.sub.AVG, based on a vector bit budget and Np_.sub.init. The method further comprises determining a final number of segments to be used, for the vector x, in the gain shape vector encoding, based on energies of the Np_.sub.init segments and a difference between B.sub.MAX and B.sub.AVG. The performing of the method enables an efficient allocation of the bits of the bit budget over the target vector.

Provided is an encoding/decoding apparatus and method of multi-channel signals. The encoding apparatus and method of multi-channel signals may encode phase information of the multi-channel signals using a quantization scheme and a lossless encoding scheme, and the decoding apparatus and method of multi-channel signals may decode the phase information using an inverse-quantization scheme and a lossless decoding scheme.

The invention relates to an encoder and a decoder and methods therein for supporting split gain shape vector encoding and decoding. The method performed by an encoder, where the encoding of each vector segment is subjected to a constraint related to a maximum number of bits, B.sub.MAX, allowed for encoding a vector segment. The method comprises, determining an initial number, Np.sub.init, of segments for a target vector x; and further determining an average number of bits per segment, B.sub.AVG, based on a vector bit budget and Np.sub.init. The method further comprises determining a final number of segments to be used, for the vector x, in the gain shape vector encoding, based on energies of the Np.sub.init segments and a difference between B.sub.MAX and B.sub.AVG. The performing of the method enables an efficient allocation of the bits of the bit budget over the target vector.

The invention relates to an encoder and a decoder and methods therein for supporting split gain shape vector encoding and decoding. The method performed by an encoder, where the encoding of each vector segment is subjected to a constraint related to a maximum number of bits, B.sub.MAX, allowed for encoding a vector segment. The method comprises, determining an initial number, Np.sub.init, of segments for a target vector x; and further determining an average number of bits per segment, B.sub.AVG, based on a vector bit budget and Np.sub.init. The method further comprises determining a final number of segments to be used, for the vector x, in the gain shape vector encoding, based on energies of the Np.sub.init segments and a difference between B.sub.MAX and B.sub.AVG. The performing of the method enables an efficient allocation of the bits of the bit budget over the target vector.