2000 Fiscal Year Final Research Report Summary
Adaptive Digital Signal Processing and Its Application to Comnmunication Systems
| Project/Area Number |
10650364
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
情報通信工学
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| Research Institution | Shimane University |
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Principal Investigator |
NISHIMURA Shotaro Interdisciplinary Faculty of Science and Engineering, Shimane University Professor, 総合理工学部, 教授 (50031092)
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| Co-Investigator(Kenkyū-buntansha) |
OHONO Shuichi Interdisciplinary Faculty of Science and Engineering, Shimane University Lecturer, 総合理工学部, 講師 (70273919)
INOUYE Yujiro Interdisciplinary Faculty of Science and Engineering, Shimane University Professor, 総合理工学部, 教授 (40029533)
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| Project Period (FY) |
1998 – 2000
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| Keywords | Adaptive Digital Filter / IIR Notch FiIter / Grandient Method / Complex Coefficient Digital Filter / Steady-State Characteristics / QPSK / Narrow-Band Interference Rejection / Spread Spectrum Communication Systems |
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| Research Abstract |
1. Steady-State Analysis of Complex Adaptive IIR Notch Filters
We present a new structure for complex adaptive infinite impulse response (IIR) notch filter which is useful for the detection of a complex sinusoid in communication and rader systems. The proposed structure is based on gradient algorithm. A quantitative analysis for the steady-state coefficient fluctuation has been obtained. It has been shown that the variance complex coefficient fluctuation does not depend on the angular frequency of the input sinusoid. The results of computer simulations are also shown which confirm the theoretical prediction.
2. Adaptive Narrow-Band Interference Suppression Using IIR Notch Filter
Improvement of direct sequence spread spectrum (DSSS) communication systems' performance using a lattice based adaptive IIR notch filter with a simplified adaptation algorithm is presented. The improvement is shown to be achieved by rejection of a narrowband interference in a received DSSS binary phase shift keying (BPSK) signal. Apart from noise associated with input additive white gaussian noise, noise attributed to leakage sinusoids due to fluctuation of steady-state variable coefficients is also analysed. Using statistical properties of notch filter and pseudonoise (PN) correlator outputs, improvement of the performance of a DSSS systems gained by the use of interference rejection filter is shown. Computer simulation results are used to confirm analytically derived expressions.
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