Browsing by Author "Wei, SW"

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A pipeline structure for high-speed step-by-step RS decoding
(2003-02-01)
Chen, TC
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Wei, CH
;
Wei, SW
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Based on a modified step-by-step decoding procedure, a high-speed pipelined Reed-Solomon decoder is presented. The decoder requires only the delay time of three 2-input XOR gates for decoding each coded symbol. The decoder can be operated in a bit rate of Gbits/sec order and thus suitable for the very high speed data transmission systems.
A two-stage Reed-Solomon decoder for coded 2(m)-QAM systems
(2000)
Chen, TC
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Wei, CH
;
Wei, SW
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A two-stage Reed-Solomon (RS) decoder for coded 2(m)-ary QAM systems is presented. This two-stage RS decoder consists of a modified step-by-step decoding algorithm as first-stage and a direct solution algorithm as second-stage. The computation complexity is reduced by a factor of (2(m)-1)/4, compared with the conventional step-by-step RS decoder.
Step-by-step decoding algorithm for Reed-Solomon codes
(2000-02-01)
Chen, TC
;
Wei, CH
;
Wei, SW
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new step-by-step decoding algorithm for decoding Reed-Solomon codes over GF(2(m)) is presented. Based on several properties of the syndrome matrices, the new step-by-step decoding algorithm can directly determine whether every received symbol is an error locator, The detection of error location is based only on the determinant of a v x v syndrome matrix, where v is the number of errors. When an error location is found, its corresponding error value can also be determined by performing a determinant division operation between two syndrome matrices. The new decoding algorithm can significantly reduce computation complexity and improve the decoding speed compared with the conventional step-by-step decoding algorithm.
Step-by-step error/erasure decoding reed-solomon codes
(2002)
Chen, TC
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Wei, CH
;
Wei, SW
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A step-by-step error/erasure decoding algorithm for Reed-Solomon codes is presented. Compared with the standard algebraic decoding, this step-by-step error/erasure decoding algorithm does not need to find the coefficients of the error location polynomial, to search the error locators, and to calculate the error evaluator and error/erasure polynomials for obtaining the error and erasure values. This algorithm can detect whether each received code symbol is an error or erasure location or not and then directly find the corresponding error or erasure value in the manner of symbol-by-symbol.
Transmission capability of discrete multitone modulation for Taiwan's subscriber loops
(1996-01-01)
Wei, SW
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Leu, ST
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Wei, CH
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電子工程學系及電子研究所
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電信研究中心
The transmission of 1.5 Mb/s and beyond data rate in the conventional twisted-pair local loops, called asymmetrical digital subscriber line (ADSL) technology, will be possible to create a new transport access capability to provide economic wideband voice/data/video integrated services directly to residential customers. The term 'asymmetric' in ADSL refers to the much higher data rate in the direction from central office (CO) to the customer and the lower rate of return (control) data from the customer to the CO. Discrete multitone (DMT) modulation has been selected as the modulation scheme in ADSL. Because the crosstalk of local loops in Taiwan is 10-15 dB worse than that in the US, the service capability of DMT ADSL for Taiwan's local loops may be different from that in other countries, and thus needs to be evaluated. On the basis of the characteristics of Taiwan's local loops, transmission capability is estimated to be 1.544 Mb/s and 6 Mb/s in Taiwan. Simulation results also show what percentage of users in Taiwan may have 1.544 Mb/s or 6 Mb/s of ADSL services. Far-end crosstalk (FEXT) and additive white Gaussian noise (AWGN) are considered to be the dominant noise sources in the work.