Innovative Methods for Mobile Frequency Hopping Radio Networks

Period of Performance: 12/18/1998 - 08/09/1999


Phase 1 SBIR

Recipient Firm

Viasat, Inc.
2290 Cosmos Court
Carlsbad, CA 92009
Principal Investigator

Research Topics


As wireless communications systems move to higher carrier frequencies, advantages of direct-sequence methods are reduced due to the decrease in channel coherence time. Frequency hopping systems will be required to gain advantages of spread spectrum systems and minimize multi-user access interference. Channel dynamics increase with higher frequency operation and provide a significant obstacle to current receive processing techniques. Co-Channel interference, is emerging as one of the greatest impacts to digital data communications systems. A new approach to receiver design, applying Per Survivor Processing (PSP), offers the opportunity to achieve dramatic performance improvements (e.g. improved acquisition, and/or interference rejection) when a large number of users, difficult dynamics and/or large chanted uncertainties are present. Further, PSP excels when the channel characteristics, the number of interferers or reflections, and other key signal parameters are unknown. Application of PSP is now becoming feasible due to the rapidly increasing computational power and decreasing price of modern digital technology. PSP algorithms have been developed and simulated for dense urban environments wit mobile users under other efforts. The focus of this proposed Phase I work will be to develop an implementation capable of demonstrating the performance improvement of PSP applied to the mobile frequency hopped application. BENEFITS: The primary benefit of this multi-phased SBIR program is the implementation high-performance, robust and cost effective processing to enhance the performance and capacity of mobile frequency hopped communication systems. Mobile network protocols that are self-configuring and robust are called for in a variety of commercial situations, and represent a significant hurdle for current commercial wireless systems. Therefore, successful new methodologies for frequency hopping radio networks will have significant commercial potential for high carrier frequency multi-user systems.