【摘要】 在直扩信号接收机中,为了提高码跟踪环的相位跟踪精度,提出一种基于FPGA的新型伪码序列产生方法,生成不同时序关系的高精度伪码序列。该方法采用类似NCO的原理,以相位累加的方式控制伪码存储表输出伪码序列,并通过改变初始相位的设置产生不同延时的伪码序列,以满足伪码跟踪算法对伪码序列的时序要求。与现阶段应用的基于移位寄存器的伪码序列产生方法相比,本方法可以产生任意时延的伪码序列,降低了对采样率的要求,精确性高、复杂度低、易于扩展。文中给出了该方法的实现框图、资源分析,仿真结果验证了方法的有效性。更多还原

【Abstract】 In order to improve phase tracking accuracy in code tracking loop,a new FPGA-based method for the formation of pseu-do-code sequences is presented to generate high precision PN code with different timing relationship.The method uses the principle of NCO which output PN code sequence by controlling the pseudo-code storage Table with the method of accumulation phase and generate different time-lapse pseudo-code sequences by changing the initial phase settings to meet the timing requirements of pseu-do-code tracking algorithm on pseudo-code sequences.Compared with the method basing on the shift register,this method can gen-erate arbitrary delay PN code sequence,reducing the demands on the sampling rate with high accuracy,low complexity and easy to expand.The paper gives the wok flow and occupied resource analysis.The effectiveness is proved by the simulation results.更多还原