Cognitive Radio Platform Technology Ivan Seskar Rutgers, The State University of New Jersey www.winlab.rutgers.edu seskar (at) winlab (dot) rutgers (dot) edu
Complexity/Performance Tradeoffs Efficient operation requires radios that can: Discover Self-Organize into hierarchical networks Cooperate Collaborate Protocol Complexity (degree of coordination) Unlicensed band + simple coord protocols Internet Internet Server-based Server-based Etiquette Etiquette Internet Internet Leasing Leasing Static Assignme Static Assignme nt nt Unlicensed Unlicensed Band Band with DCA with DCA (e.g. 802.11x) (e.g. 802.11x) Reactive Reactive Rate/Power Rate/Power Control Control Radio-level Radio-level Etiquette Etiquette Protocol Protocol Ad-hoc, Ad-hoc, Multi-hop Multi-hop Collaboration Collaboration Low power FGPA s or massively parallel CPUs in handhelds? UWB, UWB, Spread Spread Hardware Complexity Cooperative Cooperative Coding, Coding, Signal Processing Signal Processing cognitive radio schemes Agile Agile Wideband Wideband Radios Radios Do we wait for Moore s law to catch up or we need new hardware architectures for CR? Problems with existing (experimental) platforms: Analog issues: range (frequency, power), agility, cost, future proofing Digital issues: power consumption, performance vs. flexibility, cost, future proofing Ease of use issues: how do we program/control these platforms? Open Access + smart radios
Low Cost Programmable Radio (LCPR) Cost effective solution tailored for ISM/UNII bands No on-board memory Modest FPGA resources (Spartan XC3S400) 8-bit CPU USB host transfer Used as noise generator/spectrum sensor in Orbit
WARP Platform (Rice University) Xilinx Virtex-II Pro (Xilinx XC2VP70 ) FPGA 10/100 Ethernet 4 Daughtercard Slots RS-232 UART 16-bit Digital I/O Radio dauthercard 2 x 160MS/s 16-bit DAC 2 x 65MS/s 14-bit dual-adc dual-band ISM/UNII RF (2400-2500MHz, 4900-5875MHz) - MIMO capable 20 or 40MHz baseband bandwidth Design flows: Real-time OFDM Non-real-time (interfaces for MATLAB ) SISO and MIMO
USRP/USRP2 with GNU Radio Platform Pentium based SDR: Open-source GNU Radio Software - signal processing code on host computer in C++ (including FSK, PSK, AM, ASK, NBFM. WBFM, 802.11) IF 0-100 MHz (50 MHz transmit) 128 MS/s DAC 64 MS/s ADC USB bus (W = 8 MHz) Channelizer code in Altera Cyclone FPGA 2 RF board slots IF -200 MHz (80 MHz receive) 100 MS/s 14-bit dual (IQ) ADCs 400 MS/s 16-bit dual (IQ) DACs Gigabit Ethernet (W = 25 MHz) Bigger FPGA w/multipliers (Spartan 3) with 1 MB high-speed on-board SRAM and high speed serial expansion interface 1 RF board slot Selection of RF daughtercards (DC-5.9 GHz): DC-30 MHz, 50-870 MHz (Rx only), 800-2400 MHz (Rx only), 400-500 MHz, 800-1000 MHz, 1150-1450 MHz, 1500-2100 MHz, 2300-2900 MHz, 2400-2500+4900-5840 MHz
WiNC2R Platform WINC2R System Two 400 MSPS, 14-bit A/D channels Two 500 MSPS, 16-bit DAC channels Xilinx Virtex5, SX95T FPGA 1GB DDR2 DRAM 4MB QDR-II SRAM 8-lane PCI Express Host Interface ISM/UNII RF (2.4/5 GHz) Xilinx Virtex-5 LX50 FPGA 10/100/1000 Ethernet PHY 16 MB Flash 64 MB DDR2 SDRAM Cypress USB 2.0 controller 10-bit LVDS receive and transmit interfaces Dual RF front-end: 12-bit 64 MS/s ADC 12-bit 64 MS/s DAC ISM/UNII RF (2.4/5 GHz)
Virtual Flow Pipelining Architecture Hardware engine in charge of processing flow control Hardware and software modules atomic modules controlled by hw engine Properties: Low complexity (gates) High performance Simple to program High utilization of resources Programmable processing of phy and higher layer at speed target rate 500 Mbps Event driven processing model Virtualization support for controlled sharing of processing resources across multiprotocol flows Simple programming model System level: combining the hw/sw functions modules to satisfy the protocol, performance and time constraints. Software defined function
Cognitive Experiments at Scale ORBIT radio grid testbed currently supports ~15/USRP and USRP2 (GNU) radios, 100 low-cost spectrum sensors, WARP and WinC2R platforms Plan to reach ~64 cognitive radio nodes (Q1 2009) Suburban 500 meters Office 30 meters ORBIT Radio Grid 20 meters But how do we do large scale experiments in realistic environments? Urban 300 meters Radio Mapping Concept for ORBIT Emulator 400-node Radio Grid Facility at Tech Center Programmable ORBIT radio node Current ORBIT sandbox with GNU radio GENI advanced technology demonstrator of cognitive radio networks Nation-wide(experimental) cognitive radio spectrum allocation URSP CR board