Goals+and+Requirements

__**Goals and Requirements**__

At the onset of this project we were asked to design a software defined radio receiver to perform the same function as the radio JOVE receiver but with improved performance and a custom software application to process the data. We were given a few target values in terms of hardware performance and a basic description of the desired functionality of the accompanying software and from these requirements we developed our system.

System Requirements
 Since this system was supposed to be an improved model of the radio JOVE receiver, we needed ensure that we did not stray too far from the basic design features of the direct conversion receiver, mainly its portability, and ability to be powered from either a wall transformer or a battery source. With these things in mind the system had to be able to be easily transported by a single person, powered from either a wall transformer or from a DC source in the range of 13V – 20V and also have circuitry to protect the receiver from overvoltage and from applying power with the incorrect polarity. It was also specified that the system could not be solely powered via USB. The system was required to be secured within a metal enclosure, with access to connectors for an antenna input, signal out, power switch, power jacks, and access to a USB port.

Hardware Requirements
 The hardware specifications required that the system be able to measure and record a 1MHz bandwidth centered at 20.1MHz, split the signal into its in phase and quadrature components and transmit that data over USB to a personal computer. The system was required to be able to detect signals as small as 1μV at the center frequency of 20.1MHz.

 It was required that a high performance 14bit or greater ADC be used in the design. It was desired that the system have a dynamic range of approximately 100dB and it was required that the system be able to mix down the signal of interest to audio frequency before the ADC. This was to be used strictly for testing purposes to verify proper operation of the receiver.

Software Requirements
The software application was required to be run on a mid-range laptop running Linux. It should have four different modes of operation: real time, radio astronomy, full record, and data analysis.

In real time mode the application should plot to the screen frequency vs. time vs. signal strength and be able to process live data into audio which can be saved to the hard disk. The user should have control over which part of the 1MHz bandwidth is processed to audio.

In radio astronomy mode the application should give the user the ability to plot a live or previously recorded data by taking the integrated RMS average of signal energy over the entire 1MHz bandwidth and plotting this average over time. The user should also be able to export the averaged data in a parsable format.

The full record mode is required to save all unprocessed, digitized I and Q streams to a file. The user should be able to configure how much data the program should store. The user should be able to select whether a buffer should be used to only store a certain amount of data, or whether the program should continue to record until out of disk space. Also while in “Full Record” mode, a waterfall plot should be displayed.

The data analysis mode is required to give the user the ability to analyze previously recorded I/Q data recorded in “Full Record” mode or in “Radio Astronomy” mode.

A graphical user interface is required in order to present the user with different modes of operation, different ways of capturing the data, and options for what data should be captured or displayed. The GUI should have a file menu, toolbar, options area, and pane for displaying plots.