Digital signal processing for controlling error correction based on the state of the control bit

摘要

In multiplex FM broadcasting, a digital signal is composed of a frame which consists of a predetermined number of blocks in the vertical direction, a block consisting of a predetermined number of bits in the horizontal direction and having a horizontal parity (error correcting code) for correcting errors in the horizontal direction and a vertical parity for correcting errors in the vertical direction. The block also has a control bit for determining whether the error correction in the horizontal direction is to be carried out only once. A decoding identification detector (20) detects the content of the control bit, a controller (12) controls the re-writing of the digital signal into a frame buffer (13) after the error correction of the digital signal in the vertical direction by an error corrector (14). The controller (12) also controls the provision of the digital signal stored in the buffer (13) to the error corrector (14) according to the content of the control bit, determining whether the second error correction in the horizontal direction is to be carried out.