The Graphs C(t)13 are Graceful for t = 0, 3 (mod 4). - Xirong Xu; Yuansheng Yang; Lizhong Han; Huijun Li (Ars Comb., 2009)

DCT-based channel estimation for wireless OFDM systems with the hexagonal pilot pattern. - Lizhong Han; Bingyang Wu (WCSP, 2010)