N212-119 TITLE: Mobile User Objective System Dynamic Scanning Improvement

RT&L FOCUS AREA(S): Space

TECHNOLOGY AREA(S): Electronics;Space Platforms

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 3.5 of the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop a second-generation spectrally adaptive dynamic scanning algorithm to improve Mobile User Objective System (MUOS) Wideband Code Division Multiple Access (WCDMA) capable terminal UHF transmission efficiency and co-sharing spectrum supportability.

DESCRIPTION: As with any Department of Defense (DoD) radio system, radio frequency spectrum is shared and there is always the increased possibility of mutual or co-site interference. For MUOS capable radios, there are three types of interference mitigated by Spectrum Adaptation (SA): first, the MUOS radio transmission interference with the reception of non-MUOS radios (commonly called victims); second, interference to the satellite caused by other ground-based radios operating in the MUOS radio uplink frequency bands; and third, interference with the MUOS radio reception caused by non-MUOS radios operating locally within the MUOS radio’s receive carrier.

The principal approach to defining interference limits within the Ultra High Frequency (UHF) bands is defined in the National Telecommunications and Information Administration (NTIA) Redbook. Typical narrow band radios have an equivalent isotropically radiated power (EIRP) in the 10 to 100 watt range. Applying the National Telecommunications and Information Administration (NTIA) Redbook criterion, the required out-of-band emission must be in a range no greater than -25dBW to -15dBW, with spurious emissions no larger than -43dBW. Narrow band radios must comply with this Spectral Emission Mask to avoid having additional coordination requirements imposed upon it.

Currently, the MUOS spectrally adaptive waveform transmits in the UHF (300 MHz – 320 MHz) band (20 MHz with 5 MHz distinct and separate channel) – equivalent to multi-carrier WCDMA. To avoid and protect other users within the transmitted band, the MUOS waveform is designed with the capability to scan the transmitted band, determine the presence of a victim signal (based on the pre-determined threshold), and then create RF masks in the amplifier and mask out the transmitted band. The algorithm employed in this case is a modified Discrete Fourier Transform (mDFT) using a polyphaser filterbank technique [Ref 1] and amplified further [Ref 2].

The envisioned second-generation spectrally adaptive algorithm would improve the frequency resolution, achievable notch depth, minimum notch bandwidth, computation cost, and design flexibility. From there, the algorithm would be implemented into a design suitable for incorporation with the MUOS waveform software. The goal for notching bandwidth is to reduce it to 25 kiloHertz or smaller per bin. The goal for notch depth is at least 27 decibels with an objective of 30 or more. The improved notching capability must require the same or less computational complexity in order to allow for software-only updates to existing radios.

Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. owned and operated with no foreign influence as defined by DoD 5220.22-M, National Industrial Security Program Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence Security Agency (DCSA). The selected contractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances, in order to perform on advanced phases of this project as set forth by DCSA and NAVWAR in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material IAW DoD 5220.22-M during the advanced phases of this contract.

PHASE I: Create an initial conceptual design for a second-generation spectrally adaptive dynamic scanning algorithm. Predict performance using modeling and simulation or other tools. Consider radio integration issues. Estimate the power requirements and improved notch depth effectiveness. Determine the feasibility of the proposed approach to develop the algorithm to improve notch depth and scanning efficiency for MUOS radios. Develop a Phase II plan.

PHASE II: Build a prototype algorithm and simulate/test it in the spectrum-congested environment. Evaluate measured performance characteristics versus predictions from Phase I and make design adjustments as necessary. Develop a Phase III commercialization plan.

It is probable that the work under this effort will be classified under Phase II (see Description section for details).

PHASE III DUAL USE APPLICATIONS: Support the integration of the design into the existing MUOS waveform. Support interoperability testing with existing systems in a lab and through end-to-end system test.

The technology developed under this SBIR topic may be applied to a variety of SATCOM and other spectrum dependent communication systems that are currently in development.

 

REFERENCES:

1. Spooner, M.C. "Filterbanks for Adaptive Transmit Filtering." MILCOM 2007 - IEEE Military Communications Conference, Orlando, FL, USA, 2007, pp. 1-8. https://ieeexplore.ieee.org/document/4455185.
2. Commerce Spectrum Management Advisory Committee. "Interference and Dynamic Spectrum Access Committee, Interim Report, May 19, 2010." https://www.ntia.doc.gov/files/ntia/meetings/csmac_may19_idsa_final.pdf.

KEYWORDS: Mobile User Objective System; MUOS; Wideband Code Division Multiple Access; WCDMA; satellite; communications; cellular; 3G; adaptive algorithm; Spectrum Adaptation; SA; Ultra High Frequency; UHF; modified Discrete Fourier Transform; mDFT; polyphaser filte