1. A Modified Non Coherent PN Code Acquisition Scheme Rethnakaran P UbiNetics E-Mail: ratna.p@ubinetics.com, ratnu@ieee.orgratna.p@ubinetics.comratnu@ieee.org Joint work with P.K.Venkataraghavan PK (Synopsys Inc) and Tapan Ray (Wipro Technologies)

2. © UbiNetics 2004 CONFIDENTIAL Agenda Acquisition Problem Existing solutions Modified Non-coherent Detection scheme Performance Analytical, Simulation results Summary

3. © UbiNetics 2004 CONFIDENTIAL DSSS System (Transmitter) Transmit Signal

4. © UbiNetics 2004 CONFIDENTIAL DSSS System (Receiver) Received Signal Down Converted I-Q

5. © UbiNetics 2004 CONFIDENTIAL Acquisition Problem Identify (Detect) the transmitted PN code (Code Phase) from the received (I and Q) signals,

6. © UbiNetics 2004 CONFIDENTIAL System Model Receiver Structure

7. © UbiNetics 2004 CONFIDENTIAL Non Coherent Detection Scheme Non Coherent Detector Structure Why Non Coherent? Unknown Random Phase Data modulation yet to be removed Penalty Compared to Coherent scheme

8. © UbiNetics 2004 CONFIDENTIAL Modified Non Coherent Scheme DNC Structure

9. © UbiNetics 2004 CONFIDENTIAL System Model (Continued) Post Detection Integration No Post Detection (L=1) Matched Filter Based Receiver PN Sequence used AWGN No Fading DSSS/BPSK Performance Criteria – ROC Probability of Detection Vs Probability of False Alarm

10. © UbiNetics 2004 CONFIDENTIAL Analytical Results (ROC) False Alarm Probability Probability of Detection

11. © UbiNetics 2004 CONFIDENTIAL Performance (NC Versus DNC)

12. © UbiNetics 2004 CONFIDENTIAL DNC Advantage (Over NC)

13. © UbiNetics 2004 CONFIDENTIAL Simulation Results

14. © UbiNetics 2004 CONFIDENTIAL Summary New Structure Proposed Analytical Expressions (ROC) Derived 2dB SNR Advantage Over Conventional Non Coherent Scheme Supported by System Level Simulations

15. © UbiNetics 2004 CONFIDENTIAL Q&A Thank You Rethnakaran P UbiNetics E-Mail: ratna.p@ubinetics.com, ratnu@ieee.orgratna.p@ubinetics.comratnu@ieee.org http://ratnu.tripod.com http://www.ubinetics.com