Browsing by Author "KARABED, R"

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A 30-MHZ TRELLIS CODEC CHIP FOR PARTIAL-RESPONSE CHANNELS
(1991-12-01)
SHUNG, CB
;
SIEGEL, PH
;
THAPAR, HK
;
KARABED, R
;
電子工程學系及電子研究所
We present a rate 8/10 matched-spectral-null (MSN) trellis codec chip which can increase noise tolerance in partial-response channels applicable to digital magnetic recording. The Viterbi detector in this codec features an area-efficient pipelined architecture and a modulo metric normalization technique. The chip was implemented in a 1.2-mu-m CMOS process with a die size of 22 mm2. It offers a 12-Mb/s data rate when operating at 30 MHz. Experimental results verified the predicted coding gain of 2.8 dB relative to the uncoded system at a bit-error rate of 10(-7).
ON THE PERFORMANCE OF A RATE 8/10 MATCHED SPECTRAL NULL CODE FOR CLASS-4 PARTIAL RESPONSE
(1992-09-01)
THAPAR, H
;
RAE, J
;
SHUNG, C
;
KARABED, R
;
SIEGEL, P
We present the application and performance of a rate 8/10 Matched-Spectral-Null (MSN) trellis code in conjunction with Class-4 partial response (PR4) signalling. The VLSI implementation of an MSN code is described. Results of experiments using synthesized PR4 waveforms are presented and it is shown that the rate 8/10 code can provide about a 3dB advantage relative to the Class-4 partial response maximum likelihood detection (PRML) in the presence of additive white Gaussian noise as well as additive synthesized adjacent track interference.
REAL-TIME RECORDING RESULTS FOR A TRELLIS-CODED PARTIAL-RESPONSE (TCPR) SYSTEM
(1993-11-01)
THAPAR, HK
;
SHUNG, CB
;
RAE, JW
;
KARABED, R
;
SIEGEL, PH
This paper describes the results of an experimental performance comparison between a Trellis-Coded Partial Response (TCPR) system and a Partial Response Maximum Likelihood (PRML) channel, using magneto-resistive (MR) recording heads and metal film disks. Measured data confirms that the TCPR method provides substantial performance advantage in terms of ontrack error rate, offtrack capability, and areal density.