FIELD: iterative decoder for mobile communication system. SUBSTANCE: iterative decoder has its first component decoder that functions to receive first peripheral data signal, first parity signal, and systematic code signal to decode systematic code signal out of signals received, and generates primary decoded signal including second peripheral data signal. First and second peripheral data signals remove noise from input signals supplied to first and second component decoders. Second component decoder receives primary decoded signal from first component decoder and second parity signal, decodes signals received, and generates secondary decoded signal and first peripheral data signal. One or more gain controllers are inserted between first and second component decoders for controlling gain of one or both first and second peripheral data signals. EFFECT: reduced errors and their rate in bits (forty bits) and frames (forty frames). 42 cl, 6 dwg
