• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.43-45
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• 2004

This paper represents the improvement of floating point operation for AC servo motor controller based on fixed point operation DSP. TMS320F2812 has fixed point operation processing structure. The controller parameters are modified to the digitized data by scaling the original parameters. TMS320F 2812 is a 32-bit processor, and it could have enough accuracy to get the digitized data this procedure is implemented and the experiments controling a AC servo system.

• Proceedings of the KIEE Conference
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• summer
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• pp.1196-1198
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• 2004

This paper represents the improvement of floating point operation for AC servo motor controller based on fixed point operation DSP. TMS320F2812 has fixed point operation processing structure. The controller parameters are modified to the digitized data by scaling the original parameters. TMS320F 2812 is a 32-bit processor, and it could have enough accuracy to got the digitized data this procedure is implemented and the experiments controling a AC servo system.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.3
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• pp.96-105
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• 1992

The use of fixed-point digital signal processors, such as the TMS 320C25, requires scaling of data at each arithmetic step to prevent overflows while keeping the accuracy. A software which automatizes this process is developed for TMS 320C25. The programmers use a model of a hypothetical floating-point digital signal processor and a floating-point format for data representation. However, the program and data are automatically translated to a fixed-point version by this software. Thus, the execution speed is not sacrificed. A fixed-point variable has a unique binary-point location, which is dependent on the range of the variable. The range is estimated from the floating-point simulation. The number of shifts needed for arithmetic or data transfer step is determined by the binary-points of the variables associated with the operation. A fixed-point code generator is also developed by using the proposed automatic scaling software. This code generator produces floating-point assembly programs from the specifiations of FIR, IIR, and adaptive transversal filters, then floating-point programs are transformed to fixed-point versions by the automatic scaling software.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.1
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• pp.95-103
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• 2009

We improve the performance of WCDMA repeater by cancelling the feedback interference radio signal under the fixed point implementation. Floating-point DSP or FPGA to implement the ICS algorithm may have an disadvantage of high cost, To solve this problem, we suggest the ICS algorithm based on LMS under fixed point operation, and show the validity of our results by comparing with the floating-point results through numerical simulation.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.4
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• pp.331-341
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• 1991

The discrete cosine transform (DCT) is widely used in many signal processing areas, including image and speech data compression. In this paper, we investigate a fixed-point error analysis for fast DCT algorithms, namely, Lee [6], Hou [7] and Vetterli [8]. A statistical model for fixed-point error is analyzed to predict the output noise due to the fixed-point implementation. This paper deals with two's complement fixed-point data representation with truncation and rounding. For a comparison purpose, we also investigate the direct form DCT algorithm. We also propose a suitable scaling model for the fixed-point implementation to avoid an overflow occurring in the addition operation. Computer simulation results reveal that there is a close agreement between the theoretical and the experimental results. The result shows that Vetterli's algorithm is better than the other algorithms in terms of SNR.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.280-287
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• 1999

An automatic train operation(ATO) system executes the operation of constant speed travelling and fixed point parking by using microprocessors instead of drivers manual operation. This paper describes the mathematical model for the train considering unknown disturbances which consist of start resistance, travelling resistance, slope resistance, curve resistance, and so on. The speed controller of ATO system is designed by considering the disturbances. The simulation is executed to verify the speed control and fixed point parking performance and to compare its performance with that of a PID-type ATO control system under disturbances. Simulation results show that the control performance of gain scheduled control scheme fur ATO system is better than that of the conventional PID controller.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7C
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• pp.735-742
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• 2006

In this paper, we explain the operation scheme and fixed-point design method of DFE (Digital Front End), which performs DC offset compensation, automatic frequency control, and automatic gain control over the input signal to the UE (User Equipment) receiver of IEEE 802.16e OFDMA-TDD system. Then, we analyze the performance of DFE under ITU-R M. 1225 Veh-A 60km/h channel environment. To optimize the fixed-point design of DFE, we reduce the number of bit resulted from calculation without performance degradation, leading to the decreased complexity of the operation in H/W, and design the Loop filter with considering trade-off between the Acquisition time and the Stability.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.3
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• pp.114-119
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• 2001

An automatic train operation(ATO) system executes the operation of constant speed travelling and fixed point parking by using microprocessors instead of driver's manual operation. This paper describes the mathematical model for the train considering unknown disturbances which consist of start resistance, travelling resistance, slope resistance, curve resistance, and so on. The speed controller of ATO system is designed by considering the disturbances. The simulation is executed to verify the speed control and fixed point parking performance and to compare its performance with that of a PID-type ATO control system under disturbances. Simulation results show that the control performance of gain scheduled control scheme for ATO system is better than that of the conventional PID controller.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.8B
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• pp.1460-1468
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• 2000

The goal of this research is the real-time implementation of MPEG-1 Layer III audio decoder using the fixed-point digital signal processor of TMS320C6201 The main job for this work is twofold: one is to convert floating-point operation in the decoder into fixed-point operation while maintaining the high resolution, and the other is to optimize the program to make it run in real-time with memory size as small as possible. We, especially, devote much time to the descaling module in the decoder for conversion of floating-point operation into fixed-point operation with high accuracy. The inverse modified cosine transform(IMDCT) and synthesis polyphase filter bank modules are optimized in order to reduce the amount of computation and memory size. After the optimization process, in this paper, the implemented decoder uses about 26% of maximum computation capacity of TMS320C6201. The program memory, data ROM, data RAM used in the decoder are about 6.77kwords, 3.13 kwords and 9.94 kwords, respectively. Comparing the PCM output of fixed-point computation with that of floating-point computation, we achieve the signal-to-noise ratio of more than 60 dB. A real-time operation is demonstrated on the PC using the sound I/O and host communication functions in the EVM board.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.12
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• pp.514-521
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• 2006

The existing ULTC operation control strategy based on the measured data deteriorates the voltage compensation capability making the efficient corresponding to the load variation difficult by following the fixed load center point voltage. Accordingly, this paper proposes a new on-line fuzzy ULTC controller based on the designed multiple load center points which can improve the voltage compensation capability of ULTC and minimize voltage deviation by moving in real-time the load center point according to the load variation to an adequate position among the multiple load center points designed using the clustering technique. The Max-Min distance technique is adopted as the clustering technique for the decision of multiple load points from measured MTr load current and PTr voltage, and the minimum distance classifier is adopted for the decision of fuzzy output membership function. To verify the effectiveness of the proposed strategy, Visual C++ MFC-based simulation environments is developed. Finally, the superiority the proposed strategy is proved by comparing the fuzzy ULTC operation control results based on multiple load center points with the existing ULTC operation control results based on fixed load center point using the data for three day.