TECHNOLOGY AREAS: Information Systems, Sensors

ACQUISITION PROGRAM: JPEO JTRS ACAT I Airborne, Maritime, Fixed (AMF) Program

OBJECTIVE: Research and develop a multi-channel, programmable, scalable, and extensible RF-channel emulator that will enable laboratory verification of next-generation military and commercial radio and waveform capabilities by emulating a high-fidelity operationally-representative radio frequency environment for networks of 8 to 100 radio nodes.

DESCRIPTION: The Joint Tactical Radio System Program (JTRS) produces a family of multi-functional Software Defined Radio (SDR) communications systems operating within the 2 MHz to 2 GHz that provides the next generation of voice, video and data for Joint and Coalition Warfighter. A key goal of next-generation military and commercial protocols is to provide a means for greater spectral efficiency, reduced Inter-symbol Interference (ISI), resilience against interference, Multipath, and Doppler-shift distortions. Unlike legacy waveforms, newer Internet Protocol (IP) based protocols incorporate complex link adaptation algorithms that make spectrum and modulation decisions based on continuously-sensed link conditions. In order to measure their effectiveness, a real-time channel impairment high isolation emulator with extensive capabilities is required.

Existing Hardware in the loop (HWIL) channel emulators are geared towards fixed infrastructure architectures and do not provide support for Ultrawideband or wideband frequency agile mesh radio architectures. The current state of the art wideband channel emulators support 5khtz-125 Mhtz bandwidths starting at 30-225Mhtz and are geared for single protocol channel emulation for half duplex point to point satellite or terrestrial line of sight communications. This poses challenges for military communication protocols which, due to their extensive use of fast and slow frequency hopping spread spectrum algorithms, can span up to 255+ Mhtz. This limitation also impacts research communities that are investigating frequency agile or Ultrawideband protocols protocols (span over 500+ Mhtz). The ability to test a frequency agile mesh network requires a combinatorial channel count which based on existing wideband channel emulation technology would require tens to hundreds of devices for small radio counts (i.e 16 radio net could require 120 radios links) and would require a complex external RF interconnect infrastructure. The drawbacks of this approach is that isolation between emulated links would be impossible.

A key difference from commercially available emulators, is that the RF Channel Impairment emulators should be able to interconnect multiple RF channels (at a minimum 8 channels) for any given permutation of configurations. It should not be designed to work with a limited number of pre-programmed waveforms within these bands, since this limitation in commercial products is one of the drivers originating this SBIR. Unlike existing channel emulators, solutions produced herin would require significant research efforts in parallel computation and effective resource partitioning to develop an architecture that can manipulate a multitude of independent channels and recombine these channels into logically distinct networks. The goal of this system is to support channel emulation for several hundred megahertz bandwidth coverage within the 2 MHz to 2 GHz spectrum using predefined characterization input (i.e delay, attenuation, doppler shift, etc.) and real-time configurable control. The system should support satellite unlink/downlink frequency range conversions and delays of up to one second. The system should facilitate the emulation of pathloss, doppler shift, a subset of statistical fading profiles and predefined user channel characterization input.

PHASE I: Develop an architecture and a conceptual design for a modular programmable RF channel emulator that supports the waveforms and RF channel impairments described above. Perform basic proof-of-concept testing to validate the feasibility of the design. Approach may leverage COTS hardware/hardware or utilize a custom design.

PHASE II: Develop detailed designs for the Phase I modular programmable RF channel emulator and fabricate an eight-channel prototype suitable for proof of concept testing in a laboratory environment. Conduct preliminary testing demonstrating eight channel communications capability for the 2 MHz to 2 GHz range with the implemented channel impairment capabilities identified in Phase 1.

PHASE III: Transition the product into a supportable commercial product to be used in characterizing commercial cellular systems and military tactical systems.

PRIVATE SECTOR COMMERCIAL POTENTIAL: The RF impairment emulator proposed within this SBIR is far reaching and can be used to test commercial cellular applications like GSM/GPR/EDGE, PCS, WCDMA, CDMA, 3GPP LTE, WiMAX.

REFERENCES:
[1] T. Jämsä, T. Poutanen, H. Hakalahti, "Realization of a Multipath Radio Channel Simulator for Wideband Wireless Radio Systems," Proc. 7th Virginia Tech Symposium. Wireless Personal Communications, Blacksburg, Virginia, USA, June 11-13, 1997

[2] G. Judd and P. Steenkiste. "Repeatable and realistic wireless experimentation through physical emulation." In HotNets-II, Cambridge, MA, November 2003. ACM.

[3] P. Murphy, F. Lou, and J. Patrick Frantz, "A hardware testbed for the implementation and evaluation of MIMO algorithms," in Proceedings of the 2003 Conference on Mobile and Wireless Communications Networks, October 2003.

KEYWORDS: RF; channel; emulator; simulator; multipath; radio; JTRS

** TOPIC AUTHOR (TPOC) **

DoD Notice:   Between November 10 and December 12, 2010, you may talk directly with the Topic Authors to ask technical questions about the topics. Their contact information is listed above. For reasons of competitive fairness, direct communication between proposers and topic authors is not allowed starting December 13, 2011, when DoD begins accepting proposals for this solicitation.

However, proposers may still submit written questions about solicitation topics through the DoD's SBIR/STTR Interactive Topic Information System (SITIS), in which the questioner and respondent remain anonymous and all questions and answers are posted electronically for general viewing until the solicitation closes. All proposers are advised to monitor SITIS (11.1 Q&A) during the solicitation period for questions and answers, and other significant information, relevant to the SBIR 11.1 topic under which they are proposing.

If you have general questions about DoD SBIR program, please contact the DoD SBIR Help Desk at (866) 724-7457 or email weblink.