基于FPGA的射频装定系统编码模块设计

Design of enoding module of RF Setting System based on FPGA

摘要:

针对射频装定系统易受噪声和干扰的影响,导致数据装定出现错误的问题,提出在装定系统发送端对工作命令进行差错控制编码,增强系统的抗干扰能力。首先,根据(7,4)循环码信息位和监督位之间的线性关系,对工作命令进行编码,使其具有发现并纠正一个错误位的能力。其次,采用平衡Gold码进行扩频调制,使系统具有保密性强的优点。最后,在采用查表法进行正弦信号发生器设计的基础上,进行选择法的QPSK调制,具有结构简单、易于实现的优点。经实验验证,采用31位的的Gold码进行调制,系统扩频增益为14.77dB；QPSK波形频率为781.25 KHz,符合设计需求。

Abstract:

To solve the problem of wrong data setting because RF setting system is susceptible to the impact of noise and interference, a scheme that encode the work command on the end of setting system is proposed to enhance the anti-jamming capability of the system. Firstly, according to the linear relationship between information bits and oversight bits of (7,4) cyclic code, work command is encoded into error control coding, so work command has the ability to detect and correct an error bit. Secondly, the use of balanced Gold code to spread spectrum modulation make the system with the advantage of strong confidentiality. Finally, based on the design of the sinusoidal signal generator in look-up table method, conducting QPSK modulation in choice method, which has a simple structure and easy to realize. The experiments prove that using 31 bits balance Gold code to DSSS modulate, system can gain for 14.77dB; the frequency of QPSK waveform is 781.25 KHz, all meet the design requirements.