Suk-Jin Jung

A new survivor memory management method in Viterbi decoders: trace-delete method and its implementation

The well known methods for survivor path storage and decoding are the register-exchange method (REM) and the trace-back method (TBM). The REM is conceptually simple, but it is not appropriate for VLSI implementation because it requires large power consumption and large chip area. The TBM is the preferred method in the VLSI implementation of Viterbi decoders (VD) having large constraint length and high performance. However, the TBM 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 survivor memory management method called trace-delete method (TDM) and realize this algorithm in hardware (H/W) for VLSI implementation and we compare the TDM with the TBM in terms of latency, the number of memory elements, and the requirements of control logic. The main advantage of the proposed method can be found as short latency and less requirements on additional control logic. Especially, if we combine the TDM with block interleaving the implementation is even simpler than the TBM. The method is studied with particular relevance to HDTV.

A new survivor memory management method in Viterbi decoders

In this paper, we propose a new survivor memory management method called the trace-delete method (TDM). Hardware (H/W) realization of the proposed algorithm for VLSI implementation is considered. Comparison of the TDM with the trace-back method (TBM) is also provided in terms of latency, the number of memory elements, and the requirements of control logic. The main advantages of the proposed method are short latency and less requirements on additional control logic. The performance is also evaluated when the method is applied to the Grand Alliance HDTV system.

A single VSB/QAM/QPSK IC for ATSC and OpenCable/sup TM/ digital terminals

This paper presents a single IC designed for the ATSC-VSB terrestrial receiver and the OpenCable/sup TM/ digital set-top terminal. The IC integrates a VSB/QAM demodulator for in-band broadcasting with a QPSK modem for bi-directional out-of-band cable signaling. It features all-digital synchronization scheme and robust channel equalization technique applied to the common VSB/QAM demodulation. Performance evaluation of the IC has shown that it can handle effectively the severe fading effect encountered in terrestrial broadcasting and the phase noise of cable transmission channels. It is designed with 0.18 /spl mu/m CMOS technology.