A review on essentials and technical challenges of software defined radio

Since the initiation of the Joint Tactical Radio System (JTRS) program, the concept of software defined radio (SDR) has received considerable attention and significant progress has been made. While the raison d'etre of SDR is somewhat different for military and commercial applications, they share similar challenges in implementing a true SDR. A true SDR faces numerous hardware and software challenges, many of them still to be addressed by research. In the literature concerning SDR software architecture and requirements, the technology requirements tend to be sidelined. This is mainly because, in the JTRS program, the focus is on voice and low data rate applications; also, the frequency band is limited to UHF. On the other hand, the implementation cost is less of a concern for now. However, by the emergence of advance warfare technology where it is required to transport more bits per warrior to accommodate video and telemetry data, and also by introducing initiatives similar to the JTRS to other communication systems, the technology requirements of SDR have to be revisited. The paper focuses on the hardware technology aspect of SDR. The main technical objective of SDR is a versatile reconfigurable platform, which provides interoperability. The main blocks of a true SDR are: intelligent antenna; programmable RF modules; high-performance digital-to-analog (DAC) and analog-to-digital converters (ADC); digital signal processing (DSP) techniques/technology; interconnection technology.