Multi pass joint Viterbi detector decoder (MP JVDD) over AWGN/ISI channels
In this paper, a new two stage joint detector/decoder named the multi pass joint Viterbi detector decoder (MP JVDD) is proposed as an alternative to the iterative detector decoder (IDD) and the originally proposed JVDD. The MP JVDD operates on a trellis with the first stage estimating the minimum metric sequence (MMS) similar to a normal Viterbi algorithm, while the second stage utilizes the estimated MMS to perform a decoding search for the minimum metric legal codeword (MMLC) This is achieved by utilizing the parity check matrix (H) to identify survivor path transitions and illegal survivors in the trellis. The survivor path transitions occur only at nodes in the trellis corresponding to each parity check constraint. The corresponding survivors in the trellis are checked for parity upon reaching the last node of each parity check constraint in turn. The survivors violating the parity checks are discarded and thus only survivors corresponding to legal codewords make it through. In contrast to JVDD, the MP JVDD considers path transitions of survivors only at the parity check nodes. However, this has to be repeated for every parity check in H. Herein lies the multi pass nature of the algorithm one pass per parity check. Each pass has substantially fewer survivors, since possible path transitions are considered for only the parity check nodes. This results in lower memory and computational requirements for the algorithm which has been verified through extensive simulation studies.
2016 International Conference on Computing, Networking and Communications (ICNC)