Method and terminal for encoding an analog signal and a terminal for decording the encoded signal

A method for encoding an analog signal subdivided into time frames and to which a synthetic signal is matched, comprising:

• forming the synthetic signal, time frame by time frame, via a synthesis filter excited by an excitation signal;
• forming the excitation signal using at least one adaptive codebook in which an earlier excitation signal is present as a plurality of sampled values having a specific sampling interval;
• selecting a segment corresponding to a length of the time frame for the formed excitation signal from the plurality of sampled values via a basic voice frequency parameter;
• forming intermediate values defined by the basic voice frequency parameter and corresponding to the sampled values when the basic voice frequency parameter assumes a non-integer value, the forming intermediate values resulting in a reduction in a time interval between the intermediate values and the sampled values;
• and
• forming the excitation signal using the totality of intermediate values and sampled values.

A communication terminal having a transmitting unit for transmitting encoding parameters comprising:

• an analog signal divided into time frames;
• an excitation signal formed using at least one adaptive codebook that a previous excitation signal is present as a plurality of sampled values having a specific sampling interval and formed using a fixed codebook;
• a synthesis filter excited via the excitation signal;
• a synthetic signal, matching the analog signal, is formed time frame by time frame via the synthesis filter;
• a basic voice frequency parameter assuming non-integer values;
• and
• intermediate values defined by the basic voice frequency parameter are formed corresponding to the sampled values when the basic voice frequency parameter assumes a non-integer value and such that a time interval between the intermediate values and the sampled values is reduced;
• wherein the intermediate values for an entry in the fixed codebook generated by a time shifting of the fixed codebook entry,
• wherein for the formed excitation signal, a segment corresponding to the length of the time frame is selected from the plurality of sampled values via the basic voice frequency parameter, and
• wherein the totality of intermediate values and sampled values is used for forming the excitation signal.

A receiver having a receiving unit for receiving encoding parameters, comprising:

• a receiver for receiving an encoded signal;
• a computing unit configured for decoding the encoded signal,
• wherein the signal encoded via the method comprising:
• forming the synthetic signal time frame by time frame via a synthesis filter excited by an excitation signal;
• forming the excitation signal using at least one adaptive codebook in which an earlier excitation signal is present as a plurality of sampled values having a specific sampling interval;
• selecting a segment corresponding to a length of the time frame for the formed excitation signal from the plurality of sampled values via a basic voice frequency parameter that assumes a non-integer value;
• forming intermediate values defined by the basic voice frequency parameter and corresponding to the sampled values if the basic voice frequency parameter assumes a non-integer value, the forming intermediate values resulting in a reduction in a time interval between the intermediate values and the sampled values;
• and
• forming the excitation signal using the totality of intermediate values and sampled values.