• Title/Summary/Keyword: LNS (Logarithmic Number System)

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An LNS-based Low-power/Small-area FFT Processor for OFDM Systems (OFDM 시스템용 로그 수체계 기반의 저전력/저면적 FFT 프로세서)

  • Park, Sang-Deok;Shin, Kyung-Wook
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.8
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    • pp.53-60
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    • 2009
  • A low-power/small-area 128-point FFT processor is designed, which is based on logarithmic number system (LNS) and some design techniques to minimize both hardware complexity and arithmetic error. The complex-number multiplications and additions/subtractions for FFT computation are implemented with LNS adders and look-up table (LUT) rather than using conventional two's complement multipliers and adders. Our design reduces the gate counts by 21% and the memory size by 16% when compared to the conventional two's complement implementation. Also, the estimated power consumption is reduced by about 18%. The LNS-based FFT processor synthesized with 0.35 ${\mu}m$ CMOS standard cell library has 39,910 gates and 2,880 bits memory. It can compute a 128-point FIT in 2.13 ${\mu}s$ with 60 MHz@2.5V, and has the average SQNR of 40.7 dB.