In bistatic integrated sensing and communication (ISAC), the transmitter and receiver of communication and sensing are the same, so the transceiver directly shares the same channel. Considering the commonality of channel state information and sensing information of target scatterers, in this letter, we propose a bistatic sensing-aided channel estimation (SACE) scheme that exploits the superior sensing and communication performance of affine Fourier division multiplexing (AFDM). In addition, we provide a parameters selection criteria that makes AFDM a simplified orthogonal chirp division multiplexing (OCDM) and provides it with a relatively ideal ambiguity function. Simulation results show that, compared with other state-of-the-art waveforms, the AFDM with this parameters selection has not only the best sensing resolution but also the best communication performance under the proposed SACE scheme.