An Improved Joint Design of Physical Layer Network Coding and Channel Coding Based on Trellis Coded Modulation in Two-way Relay Channel

A new scheme of joint channel coding and Physical layer Network Coding (PNC) is proposed for multiple-access channel based on Trellis Coded Modulation (TCM) in the Multiple Access Control (MAC) stage of the investigated two-way relay scenario. As a result of the adoption of TCM that combines channel coding with modulation, the scheme improves the free distance of the coding sequence, thus more encoding gain is obtained. In addition, the proposed scheme takes advantage of the linearity of convolutional code and MAC-XOR NC so that digital bits of network coding can be estimated directly. In this way the complexity of the decoding at the relay node is reduced by almost 50%. The proposed scheme considers the problem of joint design of channel coding, modulation and PNC, so that the system not only increases the information transmission rate, but also guarantees the reliability.