【摘要】 根据四相相移键控 (QPSK)调制信号可等效为限带高斯随机过程及射频信道中功率放大器可等效为带通非线性模型 ,及利用功率级数描述其非线性 ,分析了在码分多址 (CDMA)系统中采用QPSK载波调制时信号通过非线性射频信道后功率谱的分布 ,利用输入、输出信号的自相关函数给出了相应的表达式 ,计算了系统三阶交调指标。该结果对CDMA基站发信机的设计是非常有用的。更多还原

【Abstract】 A rigorous approach that provides helpful predictions of radio frequency(RF) channel output spectra in CDMA wireless communication systems having nonlinear distortion effects is presented. It based on QPSK signal being equivalent to a band-limited Gaussian stochastic process characteristic and power amplifier band pass nonlinearity model theory and power series. The method yields an analytical expression for the autocorrelation function of the output signal as the statistical function of the input signal transformed by a behavioral model of the amplifier. This technique is capable of predicting 3rd-order inter-modulation(IM3) products. This result will be useful in the design of transceiver for CDMA communication systems.更多还原