CONNECTION METHODS OF THE DIFFERENTIAL CODER AND DECODER IN SOFT DECISION ERROR-CORRECTING DECODER AND A NUMBER OF QUESTIONS IN IMPLEMENTING SOFT DECISION

摘要

In the error-correcting decoder of nonsystematic convolutional code used in DPSK receiving system, there is a problem as to how to locate the place of differential encoder/decoder in the proper place, by using the differential encoder/decoder, not only the advantage of the differential encoding/decoding can be fully developed, but also the double-bit-errors resulted from differential decoding can be removed. We had discussed the problem in detail [1], [2]. In this paper we generalize the result metioned above to soft decision error-correcting decoder. The selection of the quantized table, the calculation of soft decision metic and the selection of the shreshold interval of soft decision are also discussed.