1. Modeling of RF in W-CDMA with SystemView
RENE: Wireless Cellular Radio Srikrishna Bhashyam, Sridhar Rajagopal, Kanu Chadha, Dinesh Rajan, Bryan Jones, Yuanbin Guo, Ahmad Khoshnevis, Frank Livingston, Charles Camp, Behnaam Aazhang, Joseph Cavallaro
Base-station Receiver
Coding vs Spreading in W-CDMA
Next Generation Cellular System
Multimedia capabilities
Multirate services
Guaranteed Quality of service
Higher Data Rates: 2 Mbps, 384 Kbps, 128 Kbps.
Coding error correction capability
Spreading interference cancellation.
Both cause bandwidth expansion.
Given fixed information rate and transmission bandwidth
Find ‘optimum’ trade-off between Spreading and Coding
Channel Estimator
Multiuser Detector
Demux
Decoder
Data
Pilot
Estimated Amplitudes & Delays
Demodulator
Antenna
Channel Effects
Multiple Users share spectrum
Multiple Access Interference
Multipath Fading
Additive White Gaussian Noise
Multiprocessor Implementation
Rapid Prototyping using Simulink
The Wireless Channel 5 10 15 20 25 30 35 -6 -5 -4 -3 -2
Execution time (in seconds)
Users
Single DSP implementation
2 DSP implementation
Target data rate Kbps/user
2 DSPs + 2 FPGAs
Joint estimation and detection runs on DSP, while data generation, analysis runs on host!
Direct
Reflections
noise + interference
User 1
User 2
Base-station
Accelerating the blocks in Multistage Detection
to meet real-time requirements.
Future Work
Modeling of RF in W-CDMA with SystemView
Complete system evaluation on multiple DSPs and RF hardware
Carrier offset and synchronization - multiple users
Mobile handset - low power, fixed point DSP implementation
Integrating physical layer with higher layers
Task partitioning and Parallel architectures for acceleration
NCO
AFC N
Decimation factor
Welkin
>40MSPS
ADC:
AD6640
1.Off-shelf Chips(GC1012,AD6620)
2. FPGA
Output BW=InFs/N
N: 2~64 --wideband
32~ narrow
Complete System with DSP+RF
Distortion True RF modeling (IP3,P1dB, NF…)
Real world Component Specification
Multi-domain Integration ( SystemView + Matlab)
Software Radio design with DDC/DDS
ECE Industrial Affiliates, Rice University 1999