Software Defined Radio

1. Overview

Software Defined Radio (SDR) refers to a radio communication system where components typically implemented in hardware (e.g., mixers, filters, amplifiers, modulators, demodulators, detectors) are instead implemented by means of software on a personal computer or embedded system.
SDR systems are versatile and adaptable, allowing developers to modify their radio protocols or frequencies solely through software changes, rather than alterations in hardware.
The concept of SDR exploits the flexibility of modern computing architectures to accommodate multiple signal types or standards dynamically.

Flexibility: SDRs can quickly adapt to new frequencies or standards as they emerge globally.
Cost Efficiency: By eliminating the need for multiple hardware radios designed for various signals, SDRs potentially reduce hardware costs.
Multi-standard Support: They support a variety of communications standards and protocols within the same hardware framework.

Processing Power: SDR requires significant digital signal processing (DSP) capabilities to handle real-time signal modulation/demodulation.
Latency: Software processes can introduce latencies that are not present in traditional hardware radios.
Complexity in Design: While SDRs support flexibility, designing robust software architectures that effectively implement desired functionalities can be complex.

RF Front End: Captures and converts incoming radio signals into a form that can be processed by the ADC (Analog-to-Digital Converter).
ADC/DAC: Converts analog signals to digital (ADC) for processing, and vice versa (DAC) for transmission.
Digital Signal Processor: Computes the necessary transformations on the digital signal.
Software Stack: Controls all smart radio functions including filtering, modulation/demodulation, encoding, and decoding.

Telecommunications: Supporting multi-standard wireless communication networks.
Research: Assisting researchers in developing and testing new communication protocols.
Defense and Public Safety: Enabling secure, flexible communication channels on the field.

SDR can leverage modern advances in cloud computing and AI for adaptive signal processing.

While SDR allows for rapid software changes, the dependency on high-performance computing resources might not be feasible in energy-constrained or resource-limited environments.
Security might be a concern since the ease of reprogramming can potentially allow malicious modifications if proper security measures aren’t implemented.
- see Cyber Security