射频性能和计算量的平衡是正交频分复用(OFDM)雷达信号得以应用的前提。文中使用一种子载波频谱幅度滚降的OFDM 雷达信号加权系数生成方法,通过调整滚降系数来控制过渡带中的子载波功率,保证低功率峰均比的前提下减少直接数字式频率合成(DDS)中有限长单位冲激响应(FIR)滤波器所需阶数。通过设计低计算复杂度的产生与接收方案,分析了饱和放大器幅度非线性以及模拟滤波器相位非线性对OFDM 雷达信号带来的影响,使其在现有雷达硬件平台上可实现。仿真和测试验证了文中提出方法的有效性。

The balance between the radio frequency (RF) performance and the complexity is necessary for the orthogonal frequency division multiplexing (OFDM) radar signal. A method for getting the weight values of the OFDM signals with low peak-to-average power ratio (PAPR) is developed, which can decrease the finite impulse response (FIR) filter orders in the direct digital frequency synthesis (DDS) circuit by rolling off the OFDM spectrums. The powers of the subcarriers in the filter transition band can be reduced by tuning the roll-off parameter. The OFDM radar signal’s generating and receiving architectures are designed with low computation complexity for the application on the existing radar hardware. Some effects from the RF circuits are discussed including the nonlinearity of the amplitude produced by the power amplifiers and the nonlinearity of the phase produced by the analog filters. A simulated example is provided to illustrate the performance of the proposed method. An experiment demonstrates the achieved performance.

TN957