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A System Level Implementation of a Three Node Relay Network. Group Members: Harres Bin Tariq Mohammad Taha Khan Muhammad Kumail Haider Roshaan Ahsan. What is Cooperative Communication?. The Three Node Channel. Point to Point Simulation. Transmitter Module. Transmitter.
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A System Level Implementation of a Three Node Relay Network Group Members: Harres Bin Tariq Mohammad Taha Khan Muhammad KumailHaider RoshaanAhsan
Transmitter • Image stored as array • Bit-stream formed
Cooperative Diversity Virtual MIMO for single antenna nodes Multiple transmissions in orthogonal slots
Cooperative Schemes • Comparison of a hybrid Decode Forward-Amplify Forward scheme with simple Amplify Forward • Development of a novel Compress Forward scheme
Amplify-Forward Relay Relay Xr Yr Yd1 Xs Receiver Sender Receiver Yd Xs
Hybrid-Forward Relay Relay Xr Yr Yd2 Xs Receiver Sender Receiver Yd1 Xs
Relay Try decoding the received data using CRC codes: • If decoded correctly, encode again and send to receiver in second time slot • Else switch to Amplify Forward i.e. send whatever was received in first time slot after gain correction
Decisions at the receiver • AF mode: • Decode mode: +1 -1 +1 -1
Compress Forward Scheme Relay dumped Orig. Systematic Convolutional Codes Yr W Hard Decisions BPSK Xr Parity
Compress Forward Scheme Receiver Systematic Convolutional Decoder (Viterbi decoder) recv_1 Yd1 Hard Decisions ML Detector recv_2 {0,1} Yd Hard Decisions Convolutional Decoder Received bits
ML Detector for CF scheme +1 -1 Where Pe is found using Monte Carlo Methods, on the path from S-R-D
Hardware Platforms Used USRP 1 RFX 2400 Daughterboard RFX2400 2.3-2.9 GHz Rx/Tx
Manual Driver Interfaces 1. Tools4SDR Developed By : Supelec, France Issues: Poor Data Reception & Offline Processing 2.Simulink USRP Developed By : KIT, Germany Issues: Driver Compiling Issues 3.Simulink UHD Developed By : KIT, Germany No Issues: No Compiling Issues/Blocks available in Simulink
Next Step: See Data Tx/Rx Sent Sequence of bits 0’s & 1’s Passed From a Raised Cosine Filter (Real Time Processing) Observing FFT:
Debugging Issues • Hardware • Hardware Not Functioning Properly • Verified By Testing on GNU • Software • Processing Limitations • Started Transmission and Reception on Different Hosts • Moved From Real-time to Offline Processing
Complete Point to Point Hardware Testing • Finally we tested the Hardware on a built in Point to Point System with a QPSK Demo Present in Matlab 2011a. • Demo After Presentation
Cooperative Communication Sproj 2011-2012 • Hardware realization of Amplify-Forward and Decode-Forward technique • Ubuntu as the platform • GNU radio and GRC as software • Python scripting also used for processing
Techniques Implemented Amplify-Forward Decode-Forward
Objectives Achieved • Point to Point simulation • Hardware Configuration and Functionality Testing • Compress Forward simulation
Point to Point simulation • Accomplished using matlab code • The string ‘Cooperative Communications ##’ was transmitted • Strings successfully reconstructed were observed against varying SNRs • Respective BERs computed
Hardware Functionality Testing • Accomplished using simulink model • The string ‘Hello World ###’ was transmitted • The reconstructed strings printed • Matlab code based testing in progress
Compress Forward simulation • …………………….
Future Aims and Goals • Hardware completion of point to point system • Point to Point simulation of Compress Forward • Hardware Implementation of CF technique • Re-execution of Decode-Forward and Amplify-Forward Techniques • Tx/Rx in real-time using the 3-node relay network
Future Aims and Goals • Hardware completion of point to point system • Point to Point simulation of Compress Forward • Hardware Implementation of CF technique • Re-execution of Decode-Forward and Amplify-Forward Techniques • Tx/Rx in real-time using the 3-node relay network