Spectrally Efficient Communication of Non-Orthogonal Overlapping Chirp

The scarcity of spectrum resources leads to an ever-growing demand for high spectral efficiency in wireless communication. In light of this requirement, we design non-orthogonal overlapping chirps to increase efficiency. Accordingly, a demodulation method based on a correlation matrix with low-complexity is proposed. To enhance the reliability of this system, we develop continuous orthogonal phase modulation, which avoids the correlation matrix being ill-conditioned. Moreover, we rigorously derive and utilize the oversampling gain in signal-to-noise ratio. Simulation results illustrate that with the assistance of continuous orthogonal phase modulation and oversampling gain, the proposed system are more resistant to noise and it can achieve 30 bps/Hz of spectral efficiency with lower bit error rates than that of the traditional modulation system. These performances verify the high efficiency and reliability of non-orthogonal overlapping chirp system.