Software Defined Radio

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A project to explore the creation of and applications for Software Defined Radios, which allow you to receive any radio frequency and interpret the data using software -- basically a universal radio device

Introduction

Most Radio Frequency (RF) devices utilize specialized hardware circuits (RF frontends) to filter out unwanted frequencies & noise, and to decode & interpret the signal. Different frequencies (e.g 915MHz, 2.4GHz) require different types of antennas and circuits for optimal efficiency. Different modulation techniques (e.g. AM, FM, CDMA) require different algorithms (implemented in hardware or software) to decode.

A Software Defined Radio (SDR) is an RF device that can be programmed to receive any frequency within a large range. This is usually accomplished by using multiple antennas connected to multiple RF frontends, connected to a very sensitive digital capture device that is controlled by a computer or FPGA. Software on the computer can demodulate the signal and follow the Media Access Control (MAC) protocol (if any) using programmed algorithms.


Implementation & Scratchpad

This section lists work-in-progress notes regarding implementation of SDRs

RF Frontend Options

  • A cable modem tuner module can capture 6.5MHz (IF bandwidth; limited by internal SAW filter?) centered at any frequency in the range 50MHz-890MHz (RF bandwidth)
  • AC97 soundcard codec + narrow band downconverter


Part Research

No research done yet, just collected some mentioned hardware from some links as an example

Tuners

WiNRADIO WR-G526e (20-3000Mhz) tuner/down-converter; $6000 used somewhere
Sharp BS2S7HZ1204 (950 to 2150MHz, 10 to 30MHz IF bandwidth (I/Q))
Sharp BS2S7VZ1302 (950 to 2150MHz, 10 to 30MHz IF bandwidth)
Sharp VA1S1ED5056 (143 to 862MHz, 7 or 8 MHz IF bandwidth)

Sample Devices (ADCs)

Analog Devices AD6645: 80Msps at 14 bits, and is capable of bandpass (aka direct IF) sampling
Measurement Computing ADC card (20Msps): $1300

Radio Scanners

Yaesu VR-5000 (+- 100kHz IF bandwidth): ~ 500-600 EUR
AOR AR3000A (IF bandwith unknown): 780 EUR
AOR AR8600MK2 (IF bandwith +- 2 MHz): 710 EUR
AOR AR5000A (IF bandwith +- 5MHz): 1600EUR


Links

General Info

Analog-to-Digital Converters

Radio Frequency Front End

SDR Hardware Projects

Lists of SDR Links

SDR Groups, Blogs, Posts, etc

Software

Related Topics