Direct Conversion RF Digital Receiver in L-Band for QPSK

Abstract

In today's world, radios exist in a multitude of items such as cell phones, computers, car door openers, vehicles, and televisions. Traditional hardware based radio devices limit cross-functionality and can only be modified through physical intervention. This results in higher production costs and minimal flexibility in supporting multiple waveform standards. By contrast, software defined radio technology provides an efficient and comparatively inexpensive solution to this problem, allowing multimode, multi-band and/or multi-functional wireless devices that can be enhanced using software upgrades. The processing on base band is carried out in MATLAB/ Simulink using QPSK Modulation. Necessary base band processing algorithms will be written in MATLAB/ Simulink to evaluate the performance of these algorithms. The direct conversion receiver is modeled and simulated using AD9361 with integration of Zed board and ADFMCOMMS2-EBZ board. Direct conversion receiver translates RF signal to base band signal in one stage. The model drastically reduces cost, design time, board size, weight power and results in high performance. It also reduces the problem of image frequency.  .