FPGA Implementation of High Resolution Spectral De-Noising Modules of MEMS-based Inertial Sensors

Scott Dybwad, Don McGaughey and Aboelmagd Noureldin

Abstract:	Accessibility to Inertial Navigation Systems (INS) has been severely limited by cost in the past. The introduction of low cost Micro-Electro-Mechanical-Systems (MEMS) based INS to be integrated with GPS in order to provide a reliable positioning solution has provided more wide spread use of such systems. However, MEMS-based INS suffer from a wide variety of stochastic error characteristics (bias drift, scale factor instability, randomwalk) that could be either long-term (low frequency) or short-term (high frequency). This requires sophisticated pre-filtering techniques with high-resolution spectral denoising capabilities, in order to extract the desired motion components. Fast Orthogonal Search (FOS) is one such method and has provided superior performance over other pre-filtering techniques including wavelet de-noising. This paper presents a real-time implementation of the FOS de-noising algorithm. A Field Programmable Gate Array (FPGA) was selected as a suitable hardware platform for its speed and ability to provide processing perform operations in parallel. For implementation on a FPGA, the performance of the FOS algorithm using fixed point numbers was investigated. In addition, memory requirements for cross-correlation tables used by the FOS algorithm were excessive, so optimizations in the look-up table were developed.
Published in:	Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007) September 25 - 28, 2007 Fort Worth Convention Center Fort Worth, TX
Pages:	121 - 126
Cite this article:	Dybwad, Scott, McGaughey, Don, Noureldin, Aboelmagd, "FPGA Implementation of High Resolution Spectral De-Noising Modules of MEMS-based Inertial Sensors," Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007), Fort Worth, TX, September 2007, pp. 121-126.
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