Method for generation of bit reliability information for a digital transmission system using M-ary orthogonal modulation

摘要

The method involves a superheterodyne receiver (13) receiving signals picked up by an antenna (10) and fed to a demodulator (11) whose output is delivered to a computer (12) with memory. Correspondence values (decision variables) are worked out from comparison between received and stored signals for conversion into a-posteriori symbol probabilities. The received signal constitutes symbols each representing a group of data bits. The probabilities are computed so that individual probability information is obtained for each bit of a group, and reliability values can be determined and output with the associated bits as soft data bits.