Introduction
In the era of rapid development of wireless communication technology, software defined radio (SDR) technology has become an important direction. It allows users to define the transmission and reception characteristics of radio equipment through software instead of relying on traditional hardware solutions. The flexibility and programmability of this technology has brought revolutionary changes to wireless communication. This article will introduce the basic concepts and working principles of software radio.
What is software radio?
Software radio (SDR) refers to the functions of SDR equipment can be changed through software updates and conuse of software to implement radio functions, including signal generation, modulation, transmission and reception. Unlike traditional hardware radio equipment, the figurations without replacing hardware. Software radio (SDR) usually includes a configurable RF front end and an FPGA or programmable system on chip (SoC) for performing digital functions. Commercial SDR hardware can transmit and receive signals of different frequencies, thereby realizing a variety of wireless standards from FM radio to 5G, LTE and WLAN.
The birth of software radio
Dating back to the Gulf War, the multinational forces led by the United States used a variety of communication equipment, which caused them to have difficulty communicating with each other. In May 1992, at the American Telecommunications Systems Conference, Jeo Mitola of MITRE first clearly proposed the concept of "software radio". The idea is to make all tactical radios based on the same hardware platform, install different software to form different types of radios, and complete functions of different natures. Therefore, it has software programmability. Later, the US military and Hazcltine developed a software radio called "speakeasy", the core purpose of which is to solve the problem of compatible communication between various military radio stations, including voice, data and video images.
Working principle of software radio
The working principle of software radio is to convert radio signals into digital signals, and then use software to process and analyze digital signals. Specifically, the SDR device first converts the radio signal into an intermediate frequency signal through the RF front end, and then converts the intermediate frequency signal into a digital signal through an analog-to-digital converter. Next, the digital signal is sent to a computer or embedded processor, and processed and analyzed by software to realize the radio function.
Advantages of software radio
- Super high flexibility: The function of software radio equipment can be changed by adding modules and updating configurations without replacing hardware. It can communicate with any radio station and can also serve as a radio frequency relay for other radio stations.
- Super openness: The openness of SDR technology means that anyone can use SDR equipment for communication and research. The functions of SDR equipment are realized by writing code, allowing users to customize the behavior and characteristics of radio equipment. This provides more opportunities for radio enthusiasts and also provides greater space for the development and innovation of radio equipment.
Application of software radio
The application field of software radio technology is very wide.
Military: including military communications, radar systems, electronic warfare systems, satellite communications, radio monitoring and detection, etc. Commercial: including commercial radio, commercial drone communications, wireless research and amateur radio activities, etc.
Due to its flexibility and scalability, SDR has become an important technical direction in the field of modern wireless communications. With the advancement of technology, the capabilities and applications of SDR will continue to be released.