Study on integrated radar-communication signal of OFDM-LFM based on FRFT

In view of the defects that low data transmission rate in integrated radar-communication system based on Linear Frequency Modulation (LFM), and integrated radar-communication system based on Orthogonal Frequency Division Multiplexing (OFDM) is sensitive to frequency shift, its orthogonality of subcarriers is also easily broken. For those problems, this paper presents a novel integrated radar-communication signal of OFDM-LFM, which uses orthogonal LFM signals as subcarriers and uses Fractional Fourier Transform (FRFT) as modulation and demodulation method, making a thorough analysis on spectrum distribution and factors on radar ambiguity function (AF) of integrated radar-communication signal respectively. It also takes a further research on the communication and radar performance of integrated radar-communication signal. Theoretical analysis and simulation results show that OFDM-LFM integrated signal based on FRFT achieves a great range resolution and low bit error rate (BER) compared with the traditional OFDM integrated signal in frequency selective fading condition. Moreover, it can meet the requirement of transmitting a large number of data in a short time.