1. Cornel Zlibut, Undergraduate Junior Tennessee State University
Cooperative Wireless Communication and Networked Methods for Spectrum Sharing and Interference
14 – 17 November 2011
Presented by
Dr. Wei Chen, Professor
Cornel Zlibut, Undergraduate Junior
Tennessee State University

2. Problem Statement
Study the benefits that the cooperation brings to cognitive radio networks. Focus on the cooperative MIMO technology, where multiple distributed secondary users cooperate on data transmission and reception.
Goal: Design of novel cooperative paradigms that can significantly improve the performance of both overlay and underlay systems in cognitive radio networks.

3. Approach
1. Cooperative Relay in Overlay System Multiple secondary users help primary users’ data transmission (in order to use the primary users channel)
2. Cooperative Transmission in Underlay Systems
Multiple secondary users cooperate on data transmission (in order to reduce the energy level without disturbing the primary users transmission) PR
Primary users PT
Secondary users
Primary users
Secondary users PT PR CT CR
Approach: Use MIMO technology and optimize the parameters in the cooperative relay/transmission

4. Approach - continue
3. Cooperatively limit the interference towards primary users.
Ptx: primary Tx
Prx: primary Rx
Stx: secondary Tx
Srx: secondary Rx
Ptx1
Prx1
Ptx2
Prx2
Stx1
Srx1
Stx2
Srx2
Null constraints
Null constraint

5. Evaluation and Results
Numerical analysis
Energy model:
(2) Experiment on Universal prototype testbed

6. Evaluation and Results - continue
1. Cooperative Relay in Overlay System Multiple secondary users help primary users’ data transmission (in order to use the primary users channel) PR
Primary users PT
Secondary users

7. Evaluation and Results - continue
2. Cooperative Transmission in Underlay Systems
Multiple secondary users cooperate on data transmission (in order to reduce the energy level without disturbing the primary users transmission)
Primary users
Secondary users PT PR CT CR

8. Experiment and Results
Hardware and Software Architecture
Hardware: Universal Software Radio Peripheral + RFX 2400 daughter board
Software: GNUradio
Relay Strategy: Decode and Forward
Programming Strategy
Python codes for data transmission and receiving
Visual programming for signal combination and performance evaluation S R D
Signal
Combination
If this project is a continuation of previous work, under MLP, it is acceptable to use a couple of slides under the “Problem Statement” to discuss the previous work. The overall time limit still applies.

9. Two-phase implementation
One relay node scheme
Two-phase implementation
Hardware setup
Results:
Trial
Combined
Source-Destination
Source- Relay
Relay-Destination 1
2.21%
9.13%
15.73%
7.05% 2
2.27%
12.73%
14.74%
8.20% 3
2.89%
10.76%
23.69%
8.75%
Average
2.46%
10.87%
18.05%
8.00%

10. Two-relay nodes scheme (in progress) Implementation approach
Signal
Combination S D R1 R2 R1 R2 R1 R2 D R1 R2 D R1 D R1
Signal
Combination
If this project is a continuation of previous work, under MLP, it is acceptable to use a couple of slides under the “Problem Statement” to discuss the previous work. The overall time limit still applies.