Software Defined Radio (SDR) is a reconfigurable platform whose functionality can be modified through changes in software. This flexibility makes SDR a potential communication technology for algorithm implementations. SDRs find applications in both commercial as well as military applications. In military applications, SDRs usually operate in hostile environments with diverse Quality of Service (QoS) requirements and security concerns. There are two types of security layers; (1) Transmission Security (TRANSEC), and (2) Communication Security (COMMSEC). Traditionally, Analog Frequency Hopping (FH) is employed in tactical SDRs for implementing TRANSEC. A main problem with analog FH is that a higher hop rate cannot be achieved due to tuning time bottlenecks of RF equipment.

To resolve this problem, there exists concept of Digital FH. The main idea behind digital FH is that the narrowband signal is hopped through digital mixing and subsequent digital filtering instead of RF mixing and filtering. The signal hops inside a wider analog RF band instead of the complete frequency range. This analog hop range can be changed by selecting different RF settings. Due to the usage of digital mixing and filtering, higher hop rates can easily be achieved, resulting in the enhanced security of the SDR waveform.