Integrated waveform design of ITS channel and radar communication

This article demonstrates the time-varying nature of time-frequency domain channels and the sparsity of time-delay Doppler domain channels through simulation. The concepts and formulas of ambiguity function, PAPR, and BER are given, and the basic principles and integrated system structure of OFDM modulation are introduced. The ambiguity function formula of OFDM signals is derived, and its ambiguity function is verified to be a pushpin type through simulation. The formula for PAPR of OFDM signal is given, and simulation shows that PAPR increases with the increase of subcarrier number M. Then, the basic principle and system structure of OTFS modulation were introduced, and the ambiguity function of OTFS signal was given based on OFDM signal. It was proved that the ambiguity function of OTFS signal is also a pushpin type, and the PAPR of OTFS signal was analyzed. Finally, the relationship between PAPR and symbol number N of OFDM and OTFS signals was demonstrated through simulation, as well as the BER of the two signals at different target speeds. The advantages and disadvantages of the two modulation methods were analyzed from the aspects of CP length and modulation and demodulation complexity.