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상관결과의 왜곡 방지를 위한 재양자화 방법에 관한 연구 KCI 등재
A STUDY ON THE RE-QUANTIZATION METHOD FOR PREVENTING DISTORTION OF CORRELATION RESULT
- 언어KOR
- URLhttps://db.koreascholar.com/Article/Detail/390113
pp.419-429
In this paper, we propose a new re-quantization method after FFT processing to prevent the distortion of correlation result of VCS (VLBI Correlation Subsystem). The re-quantization is used to rearrange the data bit so as to reduce the data rate processed as 16-bit of FFT result of VCS. Having done this procedure, we found that the distorted spectrum of correlation result occurred in the delay tracking experiments by the re-quantization method introduced for initial design of VCS. In order to solve this, two kinds of re-quantization method, that is, the comparison and selection-type, are proposed. The first is to re-quantize the FFT result as a valid-bit by comparing with the input data after determining the adequate threshold. The second is manually to select the valid-bit of FFT result after finding the valid-field of data according to the bit-distribution of input data. We confirmed that the second is more effective compared with the first through the experimental result, and it will be implemented without so much modification of applied method in the condition of the limited resource of FPGA. The re-quantization is, however, carried out with 4-bit in the proposed second method for FFT result, and then the distortion of correlation result is also appeared. To fix this problem, the bit for re-quantization is extended to 8-bit. The proposed 8-bit selection-type is effectively verified so that the distortion of correlation result disappeared by applying to VCS in consequence of the simulation and correlation experiments.
1. 서론
2. VCS에서 신호의 양자화
3. 제안된 재양자화 기법
3.1. 비교형 재양자화 제안
3.2. 선택형 재양자화 제안
3.3. 비교형 및 선택형 재양자화 방법의 비교
3.4. 선택형 재양자화의 확장
4. 실험결과 및 고찰
4.1. 시뮬레이션 결과
4.2. 상관처리 결과
5. 결론
참고 문헌
