CAJ | 학술논문

通过介绍直接序列扩频（DSSS）+GMSK调制的扩频系统的基本原理，分析了GMSK调制相对于MSK调制的优越性。对接收端信号先解扩后解调能有效利用扩频增益，提高系统性能。提出一种零中频直接相关的解扩解调方法。该方法在接收端先将本地扩频码进行GMSK调制，再与接收信号作相关，可以实现接收端伪码的捕获以及后续的解扩解调工作。通过Matlab仿真可以得到，在低信噪比环境下，该方法比先解调再解扩的方法有更好的误码性能。
통과개소직접서렬확빈（DSSS）+GMSK조제적확빈계통적기본원리，분석료GMSK조제상대우MSK조제적우월성。대접수단신호선해확후해조능유효이용확빈증익，제고계통성능。제출일충령중빈직접상관적해확해조방법。해방법재접수단선장본지확빈마진행GMSK조제，재여접수신호작상관，가이실현접수단위마적포획이급후속적해확해조공작。통과Matlab방진가이득도，재저신조비배경하，해방법비선해조재해확적방법유경호적오마성능。
The fundamental of spread spectrum system with direct sequence spread spectrum(DSSS)+GMSK modulation is introduced,the superiority of GMSK modulation relative to MSK modulation is analyzed. The receiving terminal signal conducted with demodulation after despreading can utilize the spread spectrum gain effectively and improve system performance. The de?spreading and demodulation method which is directly related to zero intermediate frequency is proposed. The local spread spec?trum codes are modulated with GMSK in the receiving terminal,and the modulated nodes are correlated with the received signal. The capture of pseudo code in the receiving terminal and the following dispreading and demodulation work can be realized. Mat?lab simulation results show that this method has better BER performance than the method of demodulation before despreading in low SNR environment.