Dual Function System With Shared Spectrum Using FMCW

Although an automotive radar system tends to be practical presently, it still needs to set up an extra device to achieve communication for vehicle. Considering system complexity and equipment costs, the research on automotive radar and communication integration has a very good application prospect. These days, there has been some research work on radar and communication integration based on the traditional LFMCW, but not involving triangle LFMCW, FSK, and MFSK waveform used typically for automotive radar, and its realization of dual function mainly depends on frequency diversity, meaning that systems need to occupy more spectrum resources. In this paper, a method on radar and communication integration with shared spectrum is proposed by using FMCW, which combines between Chirp-BOK modulation and FSK radar. In the system, communication information can be demodulated by decision on chirp polar, and target information can be extracted from phases of chirp. Moreover, to reduce the complexity of the receiver, a matching filter method is used commonly to complete the implementation of dual function in the system. However, it is necessary to note that the Doppler effect make phases of matching output change, which has an impact on target detection based on FSK. Therefore, the relationship of phases between Doppler and matching output will be analyzed first. Then, the system's operating principle, derivation of the algorithm, the limitation of system parameters selection, and simulation results are described in this paper.