Jonathan HawsBlair Leonard

Khemmer PorterJoshua Templin

Software Defined RadioA Modular Approach

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Review of SDR (JON)

• Software Defined Radio– Multipurpose hardware– Significant utility in military and

cellular markets– Modular architecture allows for fast

development

• Precursor to “Cognitive Radio”

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Problem (JON)

• Design a software defined radio that has the ability to:

1. Change modulation techniques “on the fly”

2. Avoid unwanted white noise3. Provide a means to easily implement

the same software on other radios

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Solution (JON)

• Code and implement on a DSP various algorithms that provide the desired functionality of the radio

• Keep code modular (C++ classes)

• Final product useful for ECE5660 course

Development Process (JON)

1. Algorithms coded in Matlab

2. Simulations performed in Matlab

3. Algorithms ported to C++

4. Simulation verification in C++

5. C++ code implemented on DSP

System Block Diagram (JON)

Matlab Coding (BLAIR)

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Matlab Simulation Results (BLAIR)

MATLAB simulation square 16-QAM modulation

Raw Signal

Demodulated Signal

C++ Coding (KHEMMER)

C++ Simulation Results (KHEMMER)

GUI Controller Software (JOSH)

RTDX Communication with SD Boards (JOSH)

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Spectrum Digital DSP Boards (JOSH/JON)

SDI TMS320C6713 DSP Boards

• 225 MHz

• 512KB Flash

• 8MB SDRAM

• Microphone, Speaker, Mono In/Out audio ports

• USB Interface

DSP Default Parameters (JON)

• Sample Rate: 96kHz• Carrier Frequency: 24kHz

– 24kHz allows for easy calculation of sine and cosine functions (+1, -1, 0, …)

• Anti-Aliasing Filter: 4kHz LPF• Bit Rate: 2400bps• Downsample Factor: 10• Bits/Symbol: 4 (Square 16-QAM)

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Modified Demonstration (JON)

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Any Questions?

We appreciate your time.Thank you for coming!