Implementation of 72 point DST-IV for 60 channel TDM-FDM transmultiplexer

The implementation of 72 point DST-IV (discrete sine transform L type four) is presented in this paper. This design is used for the 60 channel transmultiplexer (TMUX) which implements the conversion between time division multiplex (TDM) signals and frequency division multiplex (FDM) signals. Based on a newly developed fast algorithm, two cascaded printed circuit boards are designed. They are composed of general high speed integrated circuits, with structures suitable for pipeline and parallel computation. A ROM direct control mode is adopted. Combined with the use of multiplexing techniques, the above measures promise the real-time implementation of 72-point DST-IV equipment with 125 mu s time duration at 9.216 MHz clock rate.<>