宽带无线系统直接变频方式的设计与实现

为了进一步缩小宽带无线系统的体积、减小功耗，基于软件无线电的思想和专用的射频直接变频芯片，设计并实现了物理层直接变频方案。该方案使用MAX2831芯片实现射频与基带之间的直接变换，利用FPGA实现基带信号处理和射频模块的控制。详细讨论了方案的硬件结构和软件的设计方法，通过实验验证了直接变频前端的收发性能。实验结果表明，所设计的物理屡射频前端方案能够满足宽带无线通信的直接变频功能，且结构简单，便于工业应用。

Design and Realization of Direct-conversion in Wireless Broadband System

Based on the software defined radio and the specific direct-conversion integrated circuit, a physical-layer direet-conversian scheme is provided and implemented to reduce the power and size of wide-band wireless system. In the scheme, the signal conversion between RF and baseband is finished by the chip MAX2831 ,while the processing of baseband signal and controlling of RF is realized by FPGA. The scheme is discussed in detail both in software and structure of hardware, verifying the performance of direct-conversion circuit in test. The result indi- cates that, the function of direct-conversion in broadband wireless communications is realized with simple structure, helpful in industrial applications.