IEEE 802.16e OFDMA TDD 시스템 하향링크 트래픽 채널의 Fixed-point 구현 방법론

김규현,선태형,왕우붕,장경희,박형일,어익수,Kim Kyoo-Hyun,Sun Tae-Hyung,Wang Yu-Peng,Chang Kyung-Hi,Park Hyung-Il,Eo Ik-Soo 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.6A

본 논문에서는 IEEE 802.16e에 기반한 OFDMA TDD 시스템 하향 링크 트래픽 채널의 fixed-point 구현을 위해 Floating-point 모델로부터 성능 열화와 하드웨어 복잡도를 최소화 할 수 있도록 적절한 비트 사이즈를 결정하는 방법론에 대하여 기술한다. Fixed-point 구현에 있어서 여러 가지 고려 사항 중 하나는 비트 사이즈를 절사하는 방법에 따른 Saturation과 Quantization의 선택이며, 반드시 주의해야 할 점은 신호의 분포를 정확히 파악한 후 신호의 분포에 맞도록 Saturation과 Quantization 중 하나의 비트 절사방법을 적절히 적용시켜야 한다는 점이다. 또한, 시행착오를 거치면서 여러 비트 사이즈에 대하여 모의 실험을 수행하여야만 성능 열화를 최소화 하면서 원하는 비트 사이즈를 얻을 수 있다. 본 논문에서는 수신단의 트래픽 채널에 최적화된 비트 사이즈를 결정하기 위하여 AWGN 및 ITU-R M.1225의 Veh-A 채널 환경에서 컴퓨터 모의 실험을 수행한다. This paper propose to methodology for deciding suitable bit size that minimizes hardware complexity and performance degradation from floating-point design the fixed-point implementation of downlink traffic channel of IEEE 802.16e OFDMA TDD system. One of the major considering issues for implementing fixed-point design is to select Saturation or Quantization properly with the knowledge of signal distribution by pdf or histogram. Also, through trial and error, we should execute exhaustive computer simulation for various bit sizes, hence obtain appropriate bit size while minimizing performance degradation. We carry out computer simulation to decide the optimized bit size of downlink traffic channel under AWGN and ITU-R M.1225 Veh-A channel model.

Uncertainty of Radiation Thermometers Calibrated by Interpolation between Fixed Points

Yoshiro Yamada 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

An interpolation scheme for calibration of radiation thermometers in high-temperature is discussed, which utilizes one metal fixed point and one high-temperature fixed point of metal-carbon systems. The two-fixed-point interpolation scheme can realize smaller uncertainty than conventional schemes which make reference to a single fixed point, or to three or more fixed points. The two-fixed-point interpolation scheme has the advantage that no precise evaluation of the radiation thermometer spectral responsivity functionis required. This reduces the need of a regular re-evaluation of the relative spectral responsivity in the presence of filter drift, or even evaluation of the spectralresponsivity at all if the approximate filter bandwidth is known.

The fixed point property of an <i>M</i>-retract and its applications

Elsevier 2017 Topology and its applications Vol.230 No.-

<P><B>Abstract</B></P> <P>The present paper studies both the <I>fixed point property</I> (<I>FPP</I> for brevity) and the <I>almost fixed point property</I> (<I>AFPP</I> for short) for Marcus-Wyse (<I>M</I>-, for short) topological spaces by using an <I>M</I>-retract. Under <I>M</I>-topology, let S <SUB> N M </SUB> ( x ) be the smallest open neighborhood of <I>x</I>. In this paper we prove that every <I>M</I>-connected subspace of S <SUB> N M </SUB> ( x ) has the <I>FPP</I>. Let S C M 4 be a simple closed <I>M</I>-curve with four elements in <SUP> Z 2 </SUP> . Besides, consider an <I>M</I>-topological plane ( X , <SUB> γ X </SUB> ) (see ) such that S <SUB> N M </SUB> ( x ) ⊂ ( X , <SUB> γ X </SUB> ) , where <I>x</I> is a double even point or an even point. Then, proving that S C M 4 is an <I>M</I>-retract of ( X , <SUB> γ X </SUB> ) , we propose that every <I>M</I>-topological plane does not have the <I>AFPP</I>. Finally, the present paper proves the following: consider <I>M</I>-connected spaces ( <SUB> X i </SUB> , <SUB> γ <SUB> X i </SUB> </SUB> ) , where <SUB> X i </SUB> ⊂ Z , 2 ≤ | <SUB> X i </SUB> | ≨ ∞ , i ∈ { 1 , 2 } . Then the Cartesian product as an <I>M</I>-topological subspace ( <SUB> X 1 </SUB> × <SUB> X 2 </SUB> , <SUB> γ <SUB> X 1 </SUB> × <SUB> X 2 </SUB> </SUB> ) does not have the <I>AFPP</I>.</P>

Study on the Realization of Zinc Point

J. V. Widiatmo,M. Sakai,K. Yamazawa,K. Satou,J. Tamba,M. Arai 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

Two zinc-point cells were fabricated using high grade zinc samples, impurity elements of one of which were analyzed extensively. Temperature measurements during the solid-liquid coexistence, under which the zinc fixed-point is defined, were conducted, the result of which was used to perform a thermal analysis. Comparisons of zinc-point temperature realized within the newly fabricated cells were also conducted. Zinc-point depression due to impurity elements was calculated based on the chemical element analysis. Evaluation was made on the thermal analysis, the cell comparison results and the chemical element analysis, to lead to an estimation of uncertainty caused by the impurity elements. The present paper outlines the cell fabrication, the temperature measurements and the evaluation of impurity effect to the zinc-point realization.

이방성 재료의 소성변형 해석을 위한 고정점 축차

양승용,김정한 한국분말재료학회 2023 한국분말재료학회지 (KPMI) Vol.30 No.1

A fixed-point iteration is proposed to integrate the stress and state variables in the incremental analysis of plastic deformation. The Conventional Newton–Raphson method requires a second-order derivative of the yield function to generate a complicated code, and the convergence cannot be guaranteed beforehand. The proposed fixed-point iteration does not require a second-order derivative of the yield function, and convergence is ensured for a given strain increment. The fixed-point iteration is easier to implement, and the computational time is shortened compared with the Newton–Raphson method. The plane-stress condition is considered for the biaxial loading conditions to confirm the convergence of the fixed-point iteration. 3-dimensional tensile specimen is considered to compare the computational times in the ABAQUS/explicit finite element analysis.

MPEG 심리음향 모델-ll 알고리듬의 ASIC 구현을 위한 고정 소수점 연산 최적화

이근섭,박영철,윤대희,Lee Keun-Sup,Park Young-Cheol,Youn Dae Hee 한국통신학회 2004 韓國通信學會論文誌 Vol.29 No.11C

The psychoacoustic model in MPEG audio layer-III (MP3) encoder is optimized for the fixed-point processing. The optimization process consists of determining the data word length of arithmetic unit and the algorithm for transcendental functions that are often used in the psychoacoustic model. In order to determine the data word length, we defined a statistical model expressing the relation between the fixed-point operation errors of the psychoacoustic model and the probability of alteration of the allocated bits doe to these errors. Based on the simulations using this model, we chose a 24-bit data path and constructed a 24-bit fixed-point MP3 encoder. Sound quality tests using the constructed fixed-point encoder showed a mean degradation of -0.2 on ITU-R 5-point audio impairment scale. 구현하기 위하여 고정 소수점 연산기에 적합하도록 최적화를 수행하였다. 최적화 과정은 크게 부호화기의 음질을 고려하여 프로세서의 데이터 워드 길이를 결정하는 과정과 자주 사용되는 초월 함수를 고정 소수점 연산을 통해 구현하는 것으로 구성된다. 데이터 워드 길이를 결정하기 위하여 심리음향 모델 과정의 고정 소수점 연산 오차와 이 오차가 비트 할당 과정에 영향을 미칠 확률 사이의 관계를 통계적 모델로 정의하였다. 여기서 정의된 모델을 사용하여 고정 소수점 연산 오차에 의한 영향이 1% 이내가 되도록 24비트의 데이터 워드를 선택하였다. 최적화된 고정 소수점 심리음향 모델을 사용한 MP3 부호화기의 음질은 부동 소수점 부호화기에 비해 W-R의 음질평가 점수를 기준으로 평균 -0.2 이내의 구분하기 힘든 수준의 음질 저하를 보였다

SOME FIXED-POINT RESULTS ON PARAMETRIC N_b-METRIC SPACES

Tas, Nihal,Ozgur, Nihal Yilmaz Korean Mathematical Society 2018 대한수학회논문집 Vol.33 No.3

Our aim is to introduce the notion of a parametric $N_b-metric$ and study some basic properties of parametric $N_b-metric$ spaces. We give some fixed-point results on a complete parametric $N_b-metric$ space. Some illustrative examples are given to show that our results are valid as the generalizations of some known fixed-point results. As an application of this new theory, we prove a fixed-circle theorem on a parametric $N_b-metric$ space.

디지털 능동배열레이다의 빔형성을 위한 고정소수점 기반 빔형성 계수 연산기 설계 및 성능 분석

양태원,배찬희,강성모,이재용 한국전자파학회 2023 한국전자파학회논문지 Vol.34 No.12

In this study, a fixed-point-based beamforming coefficient calculator is proposed for the beamforming of a digital active array radar. Floating-point-based calculations enable precise calculations but have the disadvantages of high computational complexity and latency. To complement this, the proposed fixed-point-based beamforming coefficient calculation had a high signal to quantization noise ratio (SQNR) of 51.35 dB and the beam steering angle error was between −0.05° and 0.05° when compared with those of the floating-point calculation; these satisfied the system requirements. The proposed fixed-point-based beamforming coefficient calculator was implemented on a Xilinx Kintex UltraScale FPGA. It could reduce 54.94 % CLB register, 44.33 % CLB LUT, 60 % DSP slice, and −58.16 % latency than the floating-point calculator. Furthermore, at small beam pattern powers, the performance degradation of the calculator was less compared with previous research.

A Rule-based Optimal Placement of Scaling Shifts in Floating-point to Fixed-point Conversion for a Fixed-point Processor

Park, Sang-Hyun,Cho, Doo-San,Kim, Tae-Song,Paek, Yun-Heung The Institute of Electronics and Information Engin 2006 Journal of semiconductor technology and science Vol.6 No.4

In the past decade, several tools have been developed to automate the floating-point to fixed-point conversion for DSP systems. In the conversion process, a number of scaling shifts are introduced, and they inevitably alter the original code sequence. Recently, we have observed that a compiler can often be adversely affected by this alteration, and consequently fails to generate efficient machine code for its target processor. In this paper, we present an optimization technique that safely migrates scaling shifts to other places within the code so that the compiler can produce better-quality code. We consider our technique to be safe in that it does not introduce new overflows, yet preserving the original SQNR. The experiments on a commercial fixed-point DSP processor exhibit that our technique is effective enough to achieve tangible improvement on code size and speed for a set of benchmarks.

Circle Actions on Oriented Manifolds with Few Fixed Points

장동훈 영남수학회 2020 East Asian mathematical journal Vol.36 No.5

Let the circle act on a compact oriented manifold with a dis- crete fixed point set. At each fixed point, there are positive integers called weights, which describe the local action of S1 near the fixed point. In this paper, we provide the author’s original proof that only uses the Atiyah- Singer index formula for the classification of the weights at the fixed points if the dimension of the manifold is 4 and there are at most 4 fixed points, which made the author possible to give a classification for any finite num- ber of fixed points.