DSPs for Future Wireless Base-Stations Sridhar Rajagopal and Joseph Cavallaro ECE Dept., Rice University April 6, 2000
Overview Requirements for Future Base-Stations Current DSP Implementations Suggestions for Performance Acceleration Questions for Ray Simar Meeting with Ray Simar 12/2/2018
Evolution of Wireless Comm First Generation Voice Second/Current Generation Voice + Low-rate Data (9.6Kbps) Third Generation + Voice + High-rate Data (2 Mbps) + Multimedia W-CDMA Meeting with Ray Simar 12/2/2018
Communication System Uplink Direct Path Reflected Paths Noise +MAI User 1 User 2 Base Station Meeting with Ray Simar 12/2/2018
Main Processing Blocks Channel Estimation Detection Decoding Meeting with Ray Simar 12/2/2018
No Multiuser Detection Proposed Base-Station TI's Wireless Basestation (http://www.ti.com/sc/docs/psheets/diagrams/basestat.htm) Meeting with Ray Simar 12/2/2018
Current DSP Implementation 9 10 11 12 13 14 15 0.5 1 1.5 2 x 10 5 Number of Users Data Rates Data Rates for a typical DSP Implementation Data Rate Requirement = 128 Kbps Meeting with Ray Simar 12/2/2018
Complexity Algorithm Choice Limited by Complexity Main Features Matrix based operations High levels of parallelism Bit level computations 32x32 problem size shown Meeting with Ray Simar 12/2/2018
Reasons Sophisticated, Compute-Intensive Algorithms Not enough MIPs/FLOPs performance Unable to fully exploit pipelining or parallelism Bit - level computations / Storage Meeting with Ray Simar 12/2/2018
Our Approach Make algorithms computationally effective without sacrificing error rate performance Task Partitioning on Multiple Processing Elements DSPs : Core FPGAs : Application Specific / Bit-level Computations VLSI Implementation Meeting with Ray Simar 12/2/2018
Suggestions Bit-level storage / processing support Registers / Memory / ALU Efficient Matrix -Based operations Matrix- Vector Multiply Support for Complex-valued data Efficient memory accesses Pre-fetching Data Meeting with Ray Simar 12/2/2018
Software Suggestions Limited OS Support Compiler Efficiency No more Assembly! Performance Analysis Tools Meeting with Ray Simar 12/2/2018
Questions for Ray Simar EPIC DSP with FPGA core Multimedia Extensions In the future, what is a DSP ( as opposed to a GPP)? Branch and Control in DSPs Meeting with Ray Simar 12/2/2018
Questions for Ray Simar Online Arithmetic Truncated Multipliers Meeting with Ray Simar 12/2/2018