In this paper, a novel chirp based modulation and detection strategy for wireless communication systems using fractional Fourier transform (FrFT) is presented. In this scheme, the input data are mapped onto two chirp signals which have different initial frequencies and the same chirp rate, the received signals are detected and extracted by using FrFT. We evaluate the performance of proposed system over general additive white Gaussion noise (AWGN) channel, simulation results show that the bit error rate (BER) is improved greatly.