5. 在三条径的瑞利信道中，对于直接序列扩频：
(1)　　请设计DS-CDMA一种具体的码分导引辅助的信道估计方法，接收机分别采用等均益合并、最大比合并。用Simulink进行仿真，画出比特信噪比与信道估计均方误差的关系曲线和比特信噪比与误码率的关系曲线。
(2)　　设频率已经同步，请设计DS-CDMA一种具体的单停顿滑动相关时间同步方法，用Simulink进行仿真，画出比特信噪比与捕获概率的关系曲线。
(3)　　设时间已经同步，请设计DS-CDMA一种具体的频率同步方法，用Simulink进行仿真，画出比特信噪比与频率同步误差的关系曲线。(5. In three-path Rayleigh channel, for direct sequence spread spectrum:
(1) please design a specific code division navigation aided channel estimation method for ds-cdma, and adopt equal-beneficial combination and maximum ratio combination for receivers respectively.Simulink is used to simulate and draw the relationship curve between bit SNR and channel estimation mean square error and the relationship curve between bit SNR and bit error rate.
(2) assuming that the frequency has been synchronized, please design a specific single-stop sliding correlation time synchronization method ds-cdma, Simulink simulation, draw the relationship between the bit SNR and the acquisition probability curve.
(3) if the time has been synchronized, please design a specific frequency synchronization method ds-cdma, Simulink simulation, draw the relationship between the bit SNR and frequency synchronization error curve.)