Patent attributes
Methods, apparatus, and systems for mode assignment and mode adaptation to channel conditions are provided which are based on estimations of real signal-to-noise ratios (SNR) for each frequency carrier bearing information during a data transmission session. The invention utilizes two principal procedures: signal-to-noise ratio (SNR) estimation, and a corresponding mode assignment. SNR estimation is obtained by an averaging of squared Euclidean distances between normalized received signals and reference signals corresponding to either current hard decisions from the output of a demodulator or soft decisions provided by a decoder, for each frequency carrier bearing random information. Using the SNR estimations, various algorithms for determining mode assignment are provided.
