正弦型非线性调频键控及性能分析

以正弦型非线性调频信号为载波样本，提出一种非单频波带通调制方法--正弦型非线性调频键控（sine non-linear chirp keying， SNCK）。通过调整时间带宽积和频率变化曲线频率等参数，SNCK可实现满足不同信道环境和服务质量需求的无线通信。同时，由于采用非单频波作为载波样本，SNCK具有较好的多普勒频移抑制能力。构建SNCK的数学模型，分析已调信号正交化设计方法、频域特征及信道适应能力等性能。理论分析和实验结果表明：相较于甚小线性调频键控，SNCK具有相近的高白噪声抑制能力和频域能量集中度；相较于最小频移键控，SNCK具有更强的多普勒频移抑制能力。SNCK可作为通信终端高速率运动场景下的变速率无线通信系统的带通调制方案。

Approach to sine non-linear chirp keying modulation and performance analysis

A new kind of non-single frequency wave band pass modulation method named sine non-linear chirp keying (SNCK) is proposed which uses sinusoidal non-linear chirp signals as carriers. Adjusting parameters such as time bandwidth product or the frequencies of frequency variation curve, SNCK can be used in wireless communication systems with different qualities of service or channel characters. More importantly, SNCK has a strong ability to suppress Doppler frequency shift by using non-single frequency wave as carriers. The mathematical model of SNCK is set up, the design method of orthogonalization is given, and the performances, such as frequency domain energy concentration of modulation signals and adaptabilities of channels, are analyzed. Theoretical analysis and experimental results show that SNCK has the same suppression ability of average Gaussian white noise and frequency domain energy concentration compared with the very minimum chirp keying (VMCK), and a stronger Doppler frequency shift suppression ability than the minimum shift keying (MSK). SNCK can be used as a kind of band pass modulation scheme for variable rate wireless communication systems in communication terminals with high mobile speed.