Joint design of physical layer network coding and channel decoding based on trellis coded modulation in two-way relay channel

In this paper we consider a two-way relaying system, where two users A and B wish to exchange information with the help of a common relay R., To decode the superimposed signal from A and B efficiently, we propose a new scheme of jointing physical layer network coding (PNC) and channel decoding for multiple-access channel based on trellis coded modulation (TCM). Since TCM combines channel coding with modulation, the scheme improves the free distance of the coding sequence, thus more encoding gain is achieved. In addition, taking advantage of the linearity of convolutional code and MAC-XOR NC code, the digital bits of network coding are estimated directly. In a word, we propose a novel scheme which considers channel coding, modulation and PNC at the same time, so that not only the information transmission rate is increased, but also the reliability is improved.