METHOD AND DEVICE FOR CONVERTING STREAM OF REAL NUMBER INPUT DATA INTO COMPLEX OUTPUT SYMBOL STREAM

摘要

PROBLEM TO BE SOLVED: To efficiently convert real number data into a complex symbol, when receiving a carrier to be transmitted via a telephone line and subjected to phase modulation and amplitude modification. SOLUTION: A group stream to be formed from 2N pieces of the real number input data is converted into a complex number output symbol stream to be formed from N complex output samples by an interleave type processing. The interleave type processing is constituted of a pre-processing and a post- processing. The post-processing is timewisely nested regarding two continuos symbols, two memories of the same size which can be individually addressed are used and address specification of the two memories is executed continuously and alternately in the natural order and the reverse order, while being synchronized with a symbol clock signal.