Cooperative Wireless Communication and Networked Methods for Spectrum Sharing and Interference

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23 Νοε 2013 (πριν από 3 χρόνια και 11 μήνες)

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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

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.

Approach

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

Approach:
Use MIMO technology and optimize the parameters in the cooperative
relay/transmission

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

3.
C
ooperatively limit the interference towards primary users.

Ptx
: primary
Tx

Prx
: primary Rx

Stx
: secondary
Tx

Srx
: secondary Rx

Ptx1

Prx1

Ptx2

Prx2

S
tx1

S
r
x1

Stx2

Srx2

Null constraints

Null constraint

Null constraints

Approach
-

continue

Evaluation and Results

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E
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Evaluation

(1)
Numerical analysis


Energy model:




(2) Experiment on
Universal prototype
testbed


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

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

Experiment and Results

1.
Hardware and Software Architecture


Hardware
: Universal Software Radio Peripheral + RFX 2400
daughter
board


Software
:
GNUradio

2.
Relay Strategy: Decode and Forward






3.
Programming Strategy


Python codes for data transmission and
receiving


Visual programming for signal combination and
performance
evaluation

S

R

D

Signal

C
ombination

4.
O
ne 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%

5.
Two
-
relay nodes scheme (in progress)


Implementation approach






S

D

R1

R2

R1

R2

R1

R2

R1

D

R1

D

R1

R2

D

Signal

Combination

Signal

Combination