System and apparatus of differential coding

Abstract

Abstract PURPOSE:To attain differential coding to a stagger QAM transmission system by using a differential coding system using a new theorem. CONSTITUTION:An m-bit original information series is inputted to an input terminal 301 at each T/2 sec in a differential coder especially to a 2mX2m stagger QAM transmission system. A caption 302 is a read only memory (ROM) outputting an m-bit symbol and decided for its address in 3m-bit, and its output is fed back as a part of address of an ROM 302 and also inputted to a latch circuit 306 and a T/2-sec delay circuit 305. Latch circuits 306, 307 output a transmission code series obtained in this way at each T/2sec to output terminals 308, 309 as an in-phase data series at each Tsec and an orthogonal data series at each Tsec delayed by T/2sec from the in-phase data series. A decoder applies inversion, and the in-phase data series and the orthogonal data series at each Tsec respectively, are inputted to input terminals 401, 402.

Inventors

• 👤 Botaro Hirosaki
• 👤 廣崎　膨太郎

Bibliographic Details