A 2-STAGE DATA WORD PACKET COMMUNICATION DECODER USING RATE 1-BY-3 VITERBI DECODER AND PARITY GENERATOR

Abstract

In the field of consumer electronics the high speed communication technology applications based on hardware and software control are playing a vital role in establishing the benchmarks for catering the operational requirements of the electronic hardware to fulfil the consumer requirements in wired and wireless communication. In the modern era of communication electronics decoding and encoding of any data(s) using high speed and low power features of FPGA devices [1] based on VLSI technology offers less area, hardware portability, data security, high speed network connectivity [2], data error removal capability, complex algorithm realization, etc. Viterbi decoder is a high rate decoder that is very commonly and effectively used method in modern communication hardware. It involves Trellis coded modulation (TCM) scheme for decoding the data. The viterbi decoder is an attempt to reduce the power, speed [1], and cost as compared to normal decoders for wired and wireless communication. The work in this paper proposes a improved data error identification probability design of Viterbi decoders for communication systems with a low power operational performance. The proposed design combines the error identification capability of the viterbi decoder with parity decoder to improve the probability of the overall system in identifying the error during the communication process. Among various functional blocks in the Viterbi decoder, both hardware complexity and decoding speed highly depends on the architecture of the Decoder. The operational blocks of viterbi decoder are combined with parity testing block to identify the error in the viterbi decoded data using parity bit. The present design proposes a multi-stage pipelined architecture of decoder. The former stage is the viterbi decoding stage and the later stage is the parity decoding stage for the identification of error in the communicated data. Any Odd number of errors occuring in the recovered data from the former decoding stage can be identified using the later decoding stage. A general solution to derive the communication using conventional viterbi decoder is also given in this paper. Implementation result of proposed design for a rate 1/3 convolutional code is compared with the conventional design. The design of proposed algorithm is simulated and synthesized successfully Xilinx ISE Tool [3] on Xilinx Spartan 3E FPGA.