摘要
为解决毫米波通信系统中数据速率和频谱资源紧张的难题,采用直接数字频率合成(DDS)和锁相环(PLL)技术,基于改进的π/4-QPSK调制方式,以现场可编程门阵列(FPGA)为控制单元,设计了一种用于毫米波通信系统的QPSK调制器。重点介绍了应用FPGA实现Gold码的编码过程,并给出了Gold编码Modelsim仿真结果。测试结果表明,该毫米波调制器工作稳定,QPSK调制信号中心频率30 GHz,数据速率3 Gb/s,输出功率大于4 d Bm,相位噪声优于-100 d Bc/Hz@10 k Hz,可用于实际工程。
In order to solve the problem of low data rate and short spectrum resource in millimeter wave (MMW) communication system,a quadrature phase shift keying(QPSK) modulator is implemented with di-rect digital synthesis( DDS) and phase-locked loop( PLL) technology . This systemˊs modulation is based onπ/4-QPSK and controlled unit is implemented with Field Programmable Gate Array( FPGA) . Especially,the realization of Gold code encoding process by FPGA is introduced,and the result of Gold code Modelsim simu-lation is given. The measured results show that system works stable and frequency centers 30 GHz,data rate is 3 Gb/s,output power is greater than 4 dBm and phase noise level is better than -100 dBc/Hz at 10 kHz offset frequency. This MMW QPSK modulator can be used in practical engineering.
出处
《电讯技术》
北大核心
2015年第9期1047-1050,共4页
Telecommunication Engineering
基金
四川省教育厅重点项目(13ZA0087)~~
