超宽带正交脉冲波形设计

Optimizing orthogonal pulse waveforms for ultra-wideband communications

超宽带系统利用窄脉冲传输信息,其系统性能受脉冲的功率利用率影响.为了使脉冲波形充分利用FCC功率谱密度规范所划分的频段,该文从最大化功率利用率的角度出发,采用半正定规划的方法设计了一组脉冲超宽带的正交波形.设计得到的脉冲波形具有时域持续时间短、频域满足FCC规范及功率利用率高等优点,并且不同脉冲间在零点处互相关系数小,正交性好.通过将目标函数中的2-范数转换成1-范数,可以进一步增加正交波形的功率利用率,从而有效提高接收端的信噪比.设计结果表明这种设计方法是一种满足规范要求的较为理想的方法.

Uhra-wideband （UWB） systems use narrow pulses to transfer information; however, its performance is considerably ＇affected by the power efficiency of the pulse waveform. In order to fully utilize frequency bands as di- vided by the FCC mask, waveform power utilization efficiency must be maximized. Therefore semi-definite program- ming（SDP） was used to design a set of orthogonal waveform of uhra-wideband pulses. The pulse waveforms de- signed here have short time duration that satisfies the FCC mask in frequency domain and have high power utiliza- tion efficiency. Moreover, the orthogonality among pulses is good, which is the result of a small cross-correlation coefficient for zero time-shift when they are radiated. By transforming the 2-norm in the objective function to 1- norm, the power utilization efficiency of orthogonal pulse waveforms can be further increased to enhance the signal- to-noise ratio for the receiver.