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Optimized FPGA Implementation of Multi-Rate FIR Filters Through Thread DecompositionMultirate (decimation/interpolation) filters are among the essential signal processing components in spaceborne instruments where Finite Impulse Response (FIR) filters are often used to minimize nonlinear group delay and finite-precision effects. Cascaded (multi-stage) designs of Multi-Rate FIR (MRFIR) filters are further used for large rate change ratio, in order to lower the required throughput while simultaneously achieving comparable or better performance than single-stage designs. Traditional representation and implementation of MRFIR employ polyphase decomposition of the original filter structure, whose main purpose is to compute only the needed output at the lowest possible sampling rate. In this paper, an alternative representation and implementation technique, called TD-MRFIR (Thread Decomposition MRFIR), is presented. The basic idea is to decompose MRFIR into output computational threads, in contrast to a structural decomposition of the original filter as done in the polyphase decomposition. Each thread represents an instance of the finite convolution required to produce a single output of the MRFIR. The filter is thus viewed as a finite collection of concurrent threads. The technical details of TD-MRFIR will be explained, first showing its applicability to the implementation of downsampling, upsampling, and resampling FIR filters, and then describing a general strategy to optimally allocate the number of filter taps. A particular FPGA design of multi-stage TD-MRFIR for the L-band radar of NASA's SMAP (Soil Moisture Active Passive) instrument is demonstrated; and its implementation results in several targeted FPGA devices are summarized in terms of the functional (bit width, fixed-point error) and performance (time closure, resource usage, and power estimation) parameters.
Document ID
20150009149
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Zheng, Jason Xin
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Nguyen, Kayla
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
He, Yutao
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
June 1, 2015
Publication Date
March 6, 2010
Subject Category
Electronics And Electrical Engineering
Meeting Information
Meeting: IEEE Aerospace Conference
Location: Big Sky, MT
Country: United States
Start Date: March 6, 2010
End Date: March 13, 2010
Sponsors: Institute of Electrical and Electronics Engineers, American Inst. of Aeronautics and Astronautics
Distribution Limits
Public
Copyright
Other
Keywords
DSP

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