4. Conclusion

The development of digital radio has been made possible mainly by the following techniques:

• audio bit-rate reduction with increasingly high-performance codecs, in particular HE-AAC v2, based on a perceptual model, reconstruction of the high-frequency part of the spectrum, and parameterization of the stereo image of an audio signal;

• error-correcting detector codes and their flexibility, which, combined with interleaving-deinterleaving, enable original data to be recovered after propagation under difficult conditions;

• OFDM digital modulation (presented in