Telefonaktiebolaget Lm Ericsson (publ)

Peter Alexander Mustel

Tor Bjorn Minde

Ingemar Johansson

Tomas Lagerqvist

Hans M Nilsson

A method and arrangement for telecommunication comprises that it is detected ( ) whether an incoming signal is speech or background noise, and encoding ( ) and transmitting parameters characterising the incoming signal. In or before ( ) in the encoding of the background noise, parameters are produced, which represent background noise having increased low frequency components. Thus, the incoming signal can be subjected ( ) to a frequency tilting operation. The degree of increasing the low frequency components is determined by the maximum long term correlation of the incoming signal. This method and arrangement provides a better generation of comfort noise, when the input signal comprises low frequency sinusoids, such as engine noise from cars and trams.

Methods and arrangements in a telecommunications system

An analysis-by-synthesis linear predictive speech coder is described. This speech coder has a synthesis part including an adaptive codebook for generating an adaptive excitation, means for generating a multi-pulse excitation and means for generating a transformed binary pulse excitation. The multi-pulse excitation generating means comprises means for generating pulses in restricted pulse positions. The multi-pulse excitation and the transformed binary pulse excitation are combined.

Analysis-by-synthesis linear predictive speech coder with

In a TDMA cellular telephone system, an error concealment method provides parameter interpolation based on soft quality measures that will enhance the speech quality under bad channel conditions compared to prior methods of repeating previous voice data frames. Specifically, the soft technique of the present invention uses a weighted combination of previous and present frame parameters, where the weighting reflects the probability of error. The present invention will improve the masking of errors compared to hard actions based on a binary detection, especially when the binary detection fails or when the received frame is declared as being 'good'. The method can also utilize parameter based soft information without increasing the bitrate.

Growing community of inventors

Upplands Vasby, Sweden

Peter Alexander Mustel