2. Baseband PPM and PAM Algorithm Implementation Kenneth Rice Joel Simoneau Dr. Pearson Summer Undergraduate Research Experience

3. Purpose Main Objective: Create a library of available baseband communications algorithms Secondary Objective: Test the algorithms for efficiency and productivity based upon certain noise situations

4. Outline Pulse Amplitude Modulation Pulse Position Modulation Demodulation Techniques: Matched Filter Time Limited Accumulation Filter Direct/Reflect Path Noise Random Inversion Noise Algorithm Implementation Testing Future Work

5. Pulse Amplitude Modulation The amplitude of the pulses denote the information that is sent Example:

6. Pulse Position Modulation The location of the pulse within the specified pulse frame indicates what was sent Example

7. Matched Filter

8. Time Limited Accumulation

9. Direct/Reflected Path Noise When the transmitted signal changes path during transmission in such a way that the signal is inverted when received

10. Random Inversion Noise Transmitted signal randomly inverts at any given moment during transmission

11. Algorithm Implementation Pulse Amplitude Modulation (PAM) Pulse Amplitude Demodulation (PAD) -Matched Filter Pulse Position Modulation (PPM) Pulse Position Demodulation (PPD) -Matched Filter -Matched Filter Altered -Time Limited Accumulation (TLA) Filter -TLA Altered

12. FPGAs

13. Circuit: PAM PAM: Transmitter ‘1’ -> ‘001000’ ‘0’ -> ‘111000’

14. Circuit: PAD PAM: Receiver

15. Circuit: PPM PPM: Transmitter ‘1’ -> 0400-Hex ‘0’ -> 8000-Hex

16. Circuit: PPD-Matched PPD: Matched Receiver

17. Circuit: PPD-Matched Altered PPD: Matched Altered Receiver

18. Circuit: PPD-TLA PPD: TLA Receiver

19. Circuit: PPD-TLA Altered PPD: TLA Altered Receiver

20. Testing Table 1: Direct Path / Reflected Path Results Design101 bits1001 bits Matched44 errorsN/A Matched (Altered)0 errors TLA0 errors5 errors TLA (Altered)0 errors SNR is 4.8 for the also included Gaussian noise

21. Testing (continued) Design101 bits1001 bits Matched42 errorsN/A Matched (Altered)24 errors266 errors TLA0 errorsN/A TLA (Altered)24 errors266 errors Table 2: Random Inversion Results SNR is 4.8 for the also included Gaussian noise

22. Future Work Testing with a more accurate channel model Quantify the relative complexity of the various algorithms to give a performance versus FPGA memory trade-off

23. References [1] L.C. Ludeman, Fudamentals of Digital Signal Processing. New York: Harper and Row, 1986. [2] M.B. Pursley, Introduction to Digital Communications. New Jersey: Pearson Prentice Hall, 2005.