design of viterbi decoder with modified traceback and hybrid register exchange processing
The register-exchange method (REM) and the trace-back method (TBM) are the two well known methods for survivor path storage and decoding. The REM is logically simple, but it requires large power consumption and large chip area. The TBM is the preferred method used in Viterbi decoders (VD) having large constraint length and high performance. However, the TBM has drawbacks, which requires last-in-first-out (LIFO) buffer and has to use multiple read operations for high speed operation. This multiple operation results in complex control logic. In this paper, we propose a new two approaches or decoding methods called modified trace back method (MTBM) and hybrid register exchange method (HREM). The simulation model is ready and VLSI module is under process. The main advantage of the proposed method is that it reduces the number of decoding operation; memory read operations, less switching activity and fewer requirements on additional control logic.
hybrid register exchange method modified traceback method