Dirty Paper Coding with phase reshaping: New integration scheme for broadcast and unicast

This paper proposes a new integration scheme for broadcast and unicast in future OFDM system based on Dirty Paper Coding (DPC) to release the orthogonal resource allocation limitation to systems today. Based on the proposed DPC integration architecture, we focus on one-dimensional DPC to optimize the unicast throughput as well as guarantee the coverage of broadcast. It is shown that there is inevitable precoding loss of Tomlinson-Harashima precoding (THP) and structured DPC (SDPC) as they only consider signal amplitude for DPC encoding. The proposed DPC method, called as DPC with phase reshaping (DPC-PR), establishes a connection between DPC and phase reconstruction at the receiver. For QPSK case, link level simulation results prove that DPC-PR outperforms SDPC up to 4dB in AWGN channel. System level performance is also investigated in this paper where unicast applies DPC with known interference of broadcast and broadcast works on single frequency network (SFN) manner. Performances without DPC integration are shown for comparison.