METHOD AND ARRANGEMENT FOR CODING AND DECODING SIGNALS

摘要

A transform coder wherein different segments of signal samples to be transmitted to a receiver are encoded using different coding transforms. In order to avoid problems encountered with signal samples forming the transition between successive segments an intermediate transform is used for such transition. This has conventionally required significant transmission overhead, because the selected intermediate transform matrix must be transmitted to the receiver to enable it to decode the transitional signal samples. The invention instead provides weighting factors to indicate the extent to which frequency spectra of the basis functions of the intermediate transform resemble the frequency spectra of the basis functions of the transforms used for the adjoining signal segments. The inverse of the intermediate transform can then be calculated by the receiver from the weighting factors.