This paper proposes a new information modulation resorting to orthogonal signal and its phase for dual-function radar communication (DFRC) systems. Focusing on the standardized lin-ear frequency modulation (LFM) signal by additional phase, a bank of signals enjoying satisfactory autocorrelation and cross-correlation characteristics, are generated. Then, these signals map the dif-ferent information as well as their phases are also modulated to increase the communication bit rate, thus yielding a series of dual-use signals. Finally, the radar detection and communication per-formance of dual-use signals are also provided through numerical simulation and half-physical plat-form verification, confirming the effectiveness of the designed signals compared with the existing design strategy.